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linux/drivers/gpu/drm/drm_dp_mst_topology.c
Suraj Upadhyay 948de84233 drm : Insert blank lines after declarations. 
Resolve checkpatch issues for missing blank lines after declarations.
Issues found in multiple files with checkpatch.pl.

Signed-off-by: Suraj Upadhyay <usuraj35@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702131749.GA25710@blackclown
2020-07-02 15:26:00 +02:00

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/*
* Copyright © 2014 Red Hat
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/iopoll.h>
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
#include <linux/stacktrace.h>
#include <linux/sort.h>
#include <linux/timekeeping.h>
#include <linux/math64.h>
#endif
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_dp_mst_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_print.h>
#include <drm/drm_probe_helper.h>
#include "drm_crtc_helper_internal.h"
#include "drm_dp_mst_topology_internal.h"
/**
* DOC: dp mst helper
*
* These functions contain parts of the DisplayPort 1.2a MultiStream Transport
* protocol. The helpers contain a topology manager and bandwidth manager.
* The helpers encapsulate the sending and received of sideband msgs.
*/
struct drm_dp_pending_up_req {
struct drm_dp_sideband_msg_hdr hdr;
struct drm_dp_sideband_msg_req_body msg;
struct list_head next;
};
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf);
static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload);
static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static void
drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port);
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid);
static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
#define DBG_PREFIX "[dp_mst]"
#define DP_STR(x) [DP_ ## x] = #x
static const char *drm_dp_mst_req_type_str(u8 req_type)
{
static const char * const req_type_str[] = {
DP_STR(GET_MSG_TRANSACTION_VERSION),
DP_STR(LINK_ADDRESS),
DP_STR(CONNECTION_STATUS_NOTIFY),
DP_STR(ENUM_PATH_RESOURCES),
DP_STR(ALLOCATE_PAYLOAD),
DP_STR(QUERY_PAYLOAD),
DP_STR(RESOURCE_STATUS_NOTIFY),
DP_STR(CLEAR_PAYLOAD_ID_TABLE),
DP_STR(REMOTE_DPCD_READ),
DP_STR(REMOTE_DPCD_WRITE),
DP_STR(REMOTE_I2C_READ),
DP_STR(REMOTE_I2C_WRITE),
DP_STR(POWER_UP_PHY),
DP_STR(POWER_DOWN_PHY),
DP_STR(SINK_EVENT_NOTIFY),
DP_STR(QUERY_STREAM_ENC_STATUS),
};
if (req_type >= ARRAY_SIZE(req_type_str) ||
!req_type_str[req_type])
return "unknown";
return req_type_str[req_type];
}
#undef DP_STR
#define DP_STR(x) [DP_NAK_ ## x] = #x
static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
{
static const char * const nak_reason_str[] = {
DP_STR(WRITE_FAILURE),
DP_STR(INVALID_READ),
DP_STR(CRC_FAILURE),
DP_STR(BAD_PARAM),
DP_STR(DEFER),
DP_STR(LINK_FAILURE),
DP_STR(NO_RESOURCES),
DP_STR(DPCD_FAIL),
DP_STR(I2C_NAK),
DP_STR(ALLOCATE_FAIL),
};
if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
!nak_reason_str[nak_reason])
return "unknown";
return nak_reason_str[nak_reason];
}
#undef DP_STR
#define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
static const char *drm_dp_mst_sideband_tx_state_str(int state)
{
static const char * const sideband_reason_str[] = {
DP_STR(QUEUED),
DP_STR(START_SEND),
DP_STR(SENT),
DP_STR(RX),
DP_STR(TIMEOUT),
};
if (state >= ARRAY_SIZE(sideband_reason_str) ||
!sideband_reason_str[state])
return "unknown";
return sideband_reason_str[state];
}
static int
drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
{
int i;
u8 unpacked_rad[16];
for (i = 0; i < lct; i++) {
if (i % 2)
unpacked_rad[i] = rad[i / 2] >> 4;
else
unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
}
/* TODO: Eventually add something to printk so we can format the rad
* like this: 1.2.3
*/
return snprintf(out, len, "%*phC", lct, unpacked_rad);
}
/* sideband msg handling */
static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = num_nibbles * 4;
u8 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x10) == 0x10)
remainder ^= 0x13;
}
number_of_bits = 4;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x10) != 0)
remainder ^= 0x13;
}
return remainder;
}
static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = number_of_bytes * 8;
u16 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x100) == 0x100)
remainder ^= 0xd5;
}
number_of_bits = 8;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x100) != 0)
remainder ^= 0xd5;
}
return remainder & 0xff;
}
static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
{
u8 size = 3;
size += (hdr->lct / 2);
return size;
}
static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int *len)
{
int idx = 0;
int i;
u8 crc4;
buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
for (i = 0; i < (hdr->lct / 2); i++)
buf[idx++] = hdr->rad[i];
buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
(hdr->msg_len & 0x3f);
buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
buf[idx - 1] |= (crc4 & 0xf);
*len = idx;
}
static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int buflen, u8 *hdrlen)
{
u8 crc4;
u8 len;
int i;
u8 idx;
if (buf[0] == 0)
return false;
len = 3;
len += ((buf[0] & 0xf0) >> 4) / 2;
if (len > buflen)
return false;
crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
return false;
}
hdr->lct = (buf[0] & 0xf0) >> 4;
hdr->lcr = (buf[0] & 0xf);
idx = 1;
for (i = 0; i < (hdr->lct / 2); i++)
hdr->rad[i] = buf[idx++];
hdr->broadcast = (buf[idx] >> 7) & 0x1;
hdr->path_msg = (buf[idx] >> 6) & 0x1;
hdr->msg_len = buf[idx] & 0x3f;
idx++;
hdr->somt = (buf[idx] >> 7) & 0x1;
hdr->eomt = (buf[idx] >> 6) & 0x1;
hdr->seqno = (buf[idx] >> 4) & 0x1;
idx++;
*hdrlen = idx;
return true;
}
void
drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
int i;
u8 *buf = raw->msg;
buf[idx++] = req->req_type & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
idx++;
break;
case DP_ALLOCATE_PAYLOAD:
buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
(req->u.allocate_payload.number_sdp_streams & 0xf);
idx++;
buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
idx++;
buf[idx] = (req->u.allocate_payload.pbn >> 8);
idx++;
buf[idx] = (req->u.allocate_payload.pbn & 0xff);
idx++;
for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
(req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
idx++;
}
if (req->u.allocate_payload.number_sdp_streams & 1) {
i = req->u.allocate_payload.number_sdp_streams - 1;
buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
idx++;
}
break;
case DP_QUERY_PAYLOAD:
buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.query_payload.vcpi & 0x7f);
idx++;
break;
case DP_REMOTE_DPCD_READ:
buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_read.num_bytes);
idx++;
break;
case DP_REMOTE_DPCD_WRITE:
buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
idx += req->u.dpcd_write.num_bytes;
break;
case DP_REMOTE_I2C_READ:
buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
idx++;
for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
idx++;
buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
idx++;
memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
idx += req->u.i2c_read.transactions[i].num_bytes;
buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
idx++;
}
buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_read.num_bytes_read);
idx++;
break;
case DP_REMOTE_I2C_WRITE:
buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
idx += req->u.i2c_write.num_bytes;
break;
}
raw->cur_len = idx;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
/* Decode a sideband request we've encoded, mainly used for debugging */
int
drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
struct drm_dp_sideband_msg_req_body *req)
{
const u8 *buf = raw->msg;
int i, idx = 0;
req->req_type = buf[idx++] & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
break;
case DP_ALLOCATE_PAYLOAD:
{
struct drm_dp_allocate_payload *a =
&req->u.allocate_payload;
a->number_sdp_streams = buf[idx] & 0xf;
a->port_number = (buf[idx] >> 4) & 0xf;
WARN_ON(buf[++idx] & 0x80);
a->vcpi = buf[idx] & 0x7f;
a->pbn = buf[++idx] << 8;
a->pbn |= buf[++idx];
idx++;
for (i = 0; i < a->number_sdp_streams; i++) {
a->sdp_stream_sink[i] =
(buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
}
}
break;
case DP_QUERY_PAYLOAD:
req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
WARN_ON(buf[++idx] & 0x80);
req->u.query_payload.vcpi = buf[idx] & 0x7f;
break;
case DP_REMOTE_DPCD_READ:
{
struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
r->port_number = (buf[idx] >> 4) & 0xf;
r->dpcd_address = (buf[idx] << 16) & 0xf0000;
r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
r->dpcd_address |= buf[++idx] & 0xff;
r->num_bytes = buf[++idx];
}
break;
case DP_REMOTE_DPCD_WRITE:
{
struct drm_dp_remote_dpcd_write *w =
&req->u.dpcd_write;
w->port_number = (buf[idx] >> 4) & 0xf;
w->dpcd_address = (buf[idx] << 16) & 0xf0000;
w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
w->dpcd_address |= buf[++idx] & 0xff;
w->num_bytes = buf[++idx];
w->bytes = kmemdup(&buf[++idx], w->num_bytes,
GFP_KERNEL);
if (!w->bytes)
return -ENOMEM;
}
break;
case DP_REMOTE_I2C_READ:
{
struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
struct drm_dp_remote_i2c_read_tx *tx;
bool failed = false;
r->num_transactions = buf[idx] & 0x3;
r->port_number = (buf[idx] >> 4) & 0xf;
for (i = 0; i < r->num_transactions; i++) {
tx = &r->transactions[i];
tx->i2c_dev_id = buf[++idx] & 0x7f;
tx->num_bytes = buf[++idx];
tx->bytes = kmemdup(&buf[++idx],
tx->num_bytes,
GFP_KERNEL);
if (!tx->bytes) {
failed = true;
break;
}
idx += tx->num_bytes;
tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
tx->i2c_transaction_delay = buf[idx] & 0xf;
}
if (failed) {
for (i = 0; i < r->num_transactions; i++) {
tx = &r->transactions[i];
kfree(tx->bytes);
}
return -ENOMEM;
}
r->read_i2c_device_id = buf[++idx] & 0x7f;
r->num_bytes_read = buf[++idx];
}
break;
case DP_REMOTE_I2C_WRITE:
{
struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
w->port_number = (buf[idx] >> 4) & 0xf;
w->write_i2c_device_id = buf[++idx] & 0x7f;
w->num_bytes = buf[++idx];
w->bytes = kmemdup(&buf[++idx], w->num_bytes,
GFP_KERNEL);
if (!w->bytes)
return -ENOMEM;
}
break;
}
return 0;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
void
drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
int indent, struct drm_printer *printer)
{
int i;
#define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
if (req->req_type == DP_LINK_ADDRESS) {
/* No contents to print */
P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
return;
}
P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
indent++;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
P("port=%d\n", req->u.port_num.port_number);
break;
case DP_ALLOCATE_PAYLOAD:
P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
req->u.allocate_payload.port_number,
req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
req->u.allocate_payload.number_sdp_streams,
req->u.allocate_payload.number_sdp_streams,
req->u.allocate_payload.sdp_stream_sink);
break;
case DP_QUERY_PAYLOAD:
P("port=%d vcpi=%d\n",
req->u.query_payload.port_number,
req->u.query_payload.vcpi);
break;
case DP_REMOTE_DPCD_READ:
P("port=%d dpcd_addr=%05x len=%d\n",
req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
req->u.dpcd_read.num_bytes);
break;
case DP_REMOTE_DPCD_WRITE:
P("port=%d addr=%05x len=%d: %*ph\n",
req->u.dpcd_write.port_number,
req->u.dpcd_write.dpcd_address,
req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
req->u.dpcd_write.bytes);
break;
case DP_REMOTE_I2C_READ:
P("port=%d num_tx=%d id=%d size=%d:\n",
req->u.i2c_read.port_number,
req->u.i2c_read.num_transactions,
req->u.i2c_read.read_i2c_device_id,
req->u.i2c_read.num_bytes_read);
indent++;
for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
const struct drm_dp_remote_i2c_read_tx *rtx =
&req->u.i2c_read.transactions[i];
P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
i, rtx->i2c_dev_id, rtx->num_bytes,
rtx->no_stop_bit, rtx->i2c_transaction_delay,
rtx->num_bytes, rtx->bytes);
}
break;
case DP_REMOTE_I2C_WRITE:
P("port=%d id=%d size=%d: %*ph\n",
req->u.i2c_write.port_number,
req->u.i2c_write.write_i2c_device_id,
req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
req->u.i2c_write.bytes);
break;
default:
P("???\n");
break;
}
#undef P
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
static inline void
drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
const struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_sideband_msg_req_body req;
char buf[64];
int ret;
int i;
drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
sizeof(buf));
drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
drm_dp_mst_sideband_tx_state_str(txmsg->state),
txmsg->path_msg, buf);
ret = drm_dp_decode_sideband_req(txmsg, &req);
if (ret) {
drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
return;
}
drm_dp_dump_sideband_msg_req_body(&req, 1, p);
switch (req.req_type) {
case DP_REMOTE_DPCD_WRITE:
kfree(req.u.dpcd_write.bytes);
break;
case DP_REMOTE_I2C_READ:
for (i = 0; i < req.u.i2c_read.num_transactions; i++)
kfree(req.u.i2c_read.transactions[i].bytes);
break;
case DP_REMOTE_I2C_WRITE:
kfree(req.u.i2c_write.bytes);
break;
}
}
static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
{
u8 crc4;
crc4 = drm_dp_msg_data_crc4(msg, len);
msg[len] = crc4;
}
static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
u8 *buf = raw->msg;
buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
raw->cur_len = idx;
}
static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
struct drm_dp_sideband_msg_hdr *hdr,
u8 hdrlen)
{
/*
* ignore out-of-order messages or messages that are part of a
* failed transaction
*/
if (!hdr->somt && !msg->have_somt)
return false;
/* get length contained in this portion */
msg->curchunk_idx = 0;
msg->curchunk_len = hdr->msg_len;
msg->curchunk_hdrlen = hdrlen;
/* we have already gotten an somt - don't bother parsing */
if (hdr->somt && msg->have_somt)
return false;
if (hdr->somt) {
memcpy(&msg->initial_hdr, hdr,
sizeof(struct drm_dp_sideband_msg_hdr));
msg->have_somt = true;
}
if (hdr->eomt)
msg->have_eomt = true;
return true;
}
/* this adds a chunk of msg to the builder to get the final msg */
static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
u8 *replybuf, u8 replybuflen)
{
u8 crc4;
memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
msg->curchunk_idx += replybuflen;
if (msg->curchunk_idx >= msg->curchunk_len) {
/* do CRC */
crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
if (crc4 != msg->chunk[msg->curchunk_len - 1])
print_hex_dump(KERN_DEBUG, "wrong crc",
DUMP_PREFIX_NONE, 16, 1,
msg->chunk, msg->curchunk_len, false);
/* copy chunk into bigger msg */
memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
msg->curlen += msg->curchunk_len - 1;
}
return true;
}
static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
int i;
memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
idx += 16;
repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
for (i = 0; i < repmsg->u.link_addr.nports; i++) {
if (raw->msg[idx] & 0x80)
repmsg->u.link_addr.ports[i].input_port = 1;
repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
if (repmsg->u.link_addr.ports[i].input_port == 0)
repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
if (repmsg->u.link_addr.ports[i].input_port == 0) {
repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
idx++;
}
if (idx > raw->curlen)
goto fail_len;
}
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
idx++;
/* TODO check */
memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.vcpi = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen) {
DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
idx, raw->curlen);
return false;
}
return true;
}
static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->reply_type = (raw->msg[0] & 0x80) >> 7;
msg->req_type = (raw->msg[0] & 0x7f);
if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
memcpy(msg->u.nak.guid, &raw->msg[1], 16);
msg->u.nak.reason = raw->msg[17];
msg->u.nak.nak_data = raw->msg[18];
return false;
}
switch (msg->req_type) {
case DP_LINK_ADDRESS:
return drm_dp_sideband_parse_link_address(raw, msg);
case DP_QUERY_PAYLOAD:
return drm_dp_sideband_parse_query_payload_ack(raw, msg);
case DP_REMOTE_DPCD_READ:
return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
case DP_REMOTE_DPCD_WRITE:
return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
case DP_REMOTE_I2C_READ:
return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
case DP_ENUM_PATH_RESOURCES:
return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
case DP_ALLOCATE_PAYLOAD:
return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
case DP_POWER_DOWN_PHY:
case DP_POWER_UP_PHY:
return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
case DP_CLEAR_PAYLOAD_ID_TABLE:
return true; /* since there's nothing to parse */
default:
DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
drm_dp_mst_req_type_str(msg->req_type));
return false;
}
}
static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->req_type = (raw->msg[0] & 0x7f);
switch (msg->req_type) {
case DP_CONNECTION_STATUS_NOTIFY:
return drm_dp_sideband_parse_connection_status_notify(raw, msg);
case DP_RESOURCE_STATUS_NOTIFY:
return drm_dp_sideband_parse_resource_status_notify(raw, msg);
default:
DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
drm_dp_mst_req_type_str(msg->req_type));
return false;
}
}
static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_WRITE;
req.u.dpcd_write.port_number = port_num;
req.u.dpcd_write.dpcd_address = offset;
req.u.dpcd_write.num_bytes = num_bytes;
req.u.dpcd_write.bytes = bytes;
drm_dp_encode_sideband_req(&req, msg);
}
static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_LINK_ADDRESS;
drm_dp_encode_sideband_req(&req, msg);
}
static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
drm_dp_encode_sideband_req(&req, msg);
}
static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
int port_num)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_ENUM_PATH_RESOURCES;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
int port_num,
u8 vcpi, uint16_t pbn,
u8 number_sdp_streams,
u8 *sdp_stream_sink)
{
struct drm_dp_sideband_msg_req_body req;
memset(&req, 0, sizeof(req));
req.req_type = DP_ALLOCATE_PAYLOAD;
req.u.allocate_payload.port_number = port_num;
req.u.allocate_payload.vcpi = vcpi;
req.u.allocate_payload.pbn = pbn;
req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
number_sdp_streams);
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
}
static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
int port_num, bool power_up)
{
struct drm_dp_sideband_msg_req_body req;
if (power_up)
req.req_type = DP_POWER_UP_PHY;
else
req.req_type = DP_POWER_DOWN_PHY;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
}
static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi)
{
int ret, vcpi_ret;
mutex_lock(&mgr->payload_lock);
ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
if (ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of payload ids %d\n", ret);
goto out_unlock;
}
vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
if (vcpi_ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
goto out_unlock;
}
set_bit(ret, &mgr->payload_mask);
set_bit(vcpi_ret, &mgr->vcpi_mask);
vcpi->vcpi = vcpi_ret + 1;
mgr->proposed_vcpis[ret - 1] = vcpi;
out_unlock:
mutex_unlock(&mgr->payload_lock);
return ret;
}
static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
int vcpi)
{
int i;
if (vcpi == 0)
return;
mutex_lock(&mgr->payload_lock);
DRM_DEBUG_KMS("putting payload %d\n", vcpi);
clear_bit(vcpi - 1, &mgr->vcpi_mask);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i] &&
mgr->proposed_vcpis[i]->vcpi == vcpi) {
mgr->proposed_vcpis[i] = NULL;
clear_bit(i + 1, &mgr->payload_mask);
}
}
mutex_unlock(&mgr->payload_lock);
}
static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
unsigned int state;
/*
* All updates to txmsg->state are protected by mgr->qlock, and the two
* cases we check here are terminal states. For those the barriers
* provided by the wake_up/wait_event pair are enough.
*/
state = READ_ONCE(txmsg->state);
return (state == DRM_DP_SIDEBAND_TX_RX ||
state == DRM_DP_SIDEBAND_TX_TIMEOUT);
}
static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
unsigned long wait_timeout = msecs_to_jiffies(4000);
unsigned long wait_expires = jiffies + wait_timeout;
int ret;
for (;;) {
/*
* If the driver provides a way for this, change to
* poll-waiting for the MST reply interrupt if we didn't receive
* it for 50 msec. This would cater for cases where the HPD
* pulse signal got lost somewhere, even though the sink raised
* the corresponding MST interrupt correctly. One example is the
* Club 3D CAC-1557 TypeC -> DP adapter which for some reason
* filters out short pulses with a duration less than ~540 usec.
*
* The poll period is 50 msec to avoid missing an interrupt
* after the sink has cleared it (after a 110msec timeout
* since it raised the interrupt).
*/
ret = wait_event_timeout(mgr->tx_waitq,
check_txmsg_state(mgr, txmsg),
mgr->cbs->poll_hpd_irq ?
msecs_to_jiffies(50) :
wait_timeout);
if (ret || !mgr->cbs->poll_hpd_irq ||
time_after(jiffies, wait_expires))
break;
mgr->cbs->poll_hpd_irq(mgr);
}
mutex_lock(&mgr->qlock);
if (ret > 0) {
if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
ret = -EIO;
goto out;
}
} else {
DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
/* dump some state */
ret = -EIO;
/* remove from q */
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
list_del(&txmsg->next);
}
out:
if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
}
mutex_unlock(&mgr->qlock);
drm_dp_mst_kick_tx(mgr);
return ret;
}
static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
if (!mstb)
return NULL;
mstb->lct = lct;
if (lct > 1)
memcpy(mstb->rad, rad, lct / 2);
INIT_LIST_HEAD(&mstb->ports);
kref_init(&mstb->topology_kref);
kref_init(&mstb->malloc_kref);
return mstb;
}
static void drm_dp_free_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb =
container_of(kref, struct drm_dp_mst_branch, malloc_kref);
if (mstb->port_parent)
drm_dp_mst_put_port_malloc(mstb->port_parent);
kfree(mstb);
}
/**
* DOC: Branch device and port refcounting
*
* Topology refcount overview
* ~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* The refcounting schemes for &struct drm_dp_mst_branch and &struct
* drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
* two different kinds of refcounts: topology refcounts, and malloc refcounts.
*
* Topology refcounts are not exposed to drivers, and are handled internally
* by the DP MST helpers. The helpers use them in order to prevent the
* in-memory topology state from being changed in the middle of critical
* operations like changing the internal state of payload allocations. This
* means each branch and port will be considered to be connected to the rest
* of the topology until its topology refcount reaches zero. Additionally,
* for ports this means that their associated &struct drm_connector will stay
* registered with userspace until the port's refcount reaches 0.
*
* Malloc refcount overview
* ~~~~~~~~~~~~~~~~~~~~~~~~
*
* Malloc references are used to keep a &struct drm_dp_mst_port or &struct
* drm_dp_mst_branch allocated even after all of its topology references have
* been dropped, so that the driver or MST helpers can safely access each
* branch's last known state before it was disconnected from the topology.
* When the malloc refcount of a port or branch reaches 0, the memory
* allocation containing the &struct drm_dp_mst_branch or &struct
* drm_dp_mst_port respectively will be freed.
*
* For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
* to drivers. As of writing this documentation, there are no drivers that
* have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
* helpers. Exposing this API to drivers in a race-free manner would take more
* tweaking of the refcounting scheme, however patches are welcome provided
* there is a legitimate driver usecase for this.
*
* Refcount relationships in a topology
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* Let's take a look at why the relationship between topology and malloc
* refcounts is designed the way it is.
*
* .. kernel-figure:: dp-mst/topology-figure-1.dot
*
* An example of topology and malloc refs in a DP MST topology with two
* active payloads. Topology refcount increments are indicated by solid
* lines, and malloc refcount increments are indicated by dashed lines.
* Each starts from the branch which incremented the refcount, and ends at
* the branch to which the refcount belongs to, i.e. the arrow points the
* same way as the C pointers used to reference a structure.
*
* As you can see in the above figure, every branch increments the topology
* refcount of its children, and increments the malloc refcount of its
* parent. Additionally, every payload increments the malloc refcount of its
* assigned port by 1.
*
* So, what would happen if MSTB #3 from the above figure was unplugged from
* the system, but the driver hadn't yet removed payload #2 from port #3? The
* topology would start to look like the figure below.
*
* .. kernel-figure:: dp-mst/topology-figure-2.dot
*
* Ports and branch devices which have been released from memory are
* colored grey, and references which have been removed are colored red.
*
* Whenever a port or branch device's topology refcount reaches zero, it will
* decrement the topology refcounts of all its children, the malloc refcount
* of its parent, and finally its own malloc refcount. For MSTB #4 and port
* #4, this means they both have been disconnected from the topology and freed
* from memory. But, because payload #2 is still holding a reference to port
* #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
* is still accessible from memory. This also means port #3 has not yet
* decremented the malloc refcount of MSTB #3, so its &struct
* drm_dp_mst_branch will also stay allocated in memory until port #3's
* malloc refcount reaches 0.
*
* This relationship is necessary because in order to release payload #2, we
* need to be able to figure out the last relative of port #3 that's still
* connected to the topology. In this case, we would travel up the topology as
* shown below.
*
* .. kernel-figure:: dp-mst/topology-figure-3.dot
*
* And finally, remove payload #2 by communicating with port #2 through
* sideband transactions.
*/
/**
* drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
* device
* @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
*
* Increments &drm_dp_mst_branch.malloc_kref. When
* &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
* will be released and @mstb may no longer be used.
*
* See also: drm_dp_mst_put_mstb_malloc()
*/
static void
drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
{
kref_get(&mstb->malloc_kref);
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
}
/**
* drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
* device
* @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
*
* Decrements &drm_dp_mst_branch.malloc_kref. When
* &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
* will be released and @mstb may no longer be used.
*
* See also: drm_dp_mst_get_mstb_malloc()
*/
static void
drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
{
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
}
static void drm_dp_free_mst_port(struct kref *kref)
{
struct drm_dp_mst_port *port =
container_of(kref, struct drm_dp_mst_port, malloc_kref);
drm_dp_mst_put_mstb_malloc(port->parent);
kfree(port);
}
/**
* drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
* @port: The &struct drm_dp_mst_port to increment the malloc refcount of
*
* Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
* reaches 0, the memory allocation for @port will be released and @port may
* no longer be used.
*
* Because @port could potentially be freed at any time by the DP MST helpers
* if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
* function, drivers that which to make use of &struct drm_dp_mst_port should
* ensure that they grab at least one main malloc reference to their MST ports
* in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
* there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
*
* See also: drm_dp_mst_put_port_malloc()
*/
void
drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
{
kref_get(&port->malloc_kref);
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
}
EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
/**
* drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
* @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
*
* Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
* reaches 0, the memory allocation for @port will be released and @port may
* no longer be used.
*
* See also: drm_dp_mst_get_port_malloc()
*/
void
drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
{
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
kref_put(&port->malloc_kref, drm_dp_free_mst_port);
}
EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
#define STACK_DEPTH 8
static noinline void
__topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_topology_ref_history *history,
enum drm_dp_mst_topology_ref_type type)
{
struct drm_dp_mst_topology_ref_entry *entry = NULL;
depot_stack_handle_t backtrace;
ulong stack_entries[STACK_DEPTH];
uint n;
int i;
n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
if (!backtrace)
return;
/* Try to find an existing entry for this backtrace */
for (i = 0; i < history->len; i++) {
if (history->entries[i].backtrace == backtrace) {
entry = &history->entries[i];
break;
}
}
/* Otherwise add one */
if (!entry) {
struct drm_dp_mst_topology_ref_entry *new;
int new_len = history->len + 1;
new = krealloc(history->entries, sizeof(*new) * new_len,
GFP_KERNEL);
if (!new)
return;
entry = &new[history->len];
history->len = new_len;
history->entries = new;
entry->backtrace = backtrace;
entry->type = type;
entry->count = 0;
}
entry->count++;
entry->ts_nsec = ktime_get_ns();
}
static int
topology_ref_history_cmp(const void *a, const void *b)
{
const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
if (entry_a->ts_nsec > entry_b->ts_nsec)
return 1;
else if (entry_a->ts_nsec < entry_b->ts_nsec)
return -1;
else
return 0;
}
static inline const char *
topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
{
if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
return "get";
else
return "put";
}
static void
__dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
void *ptr, const char *type_str)
{
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
int i;
if (!buf)
return;
if (!history->len)
goto out;
/* First, sort the list so that it goes from oldest to newest
* reference entry
*/
sort(history->entries, history->len, sizeof(*history->entries),
topology_ref_history_cmp, NULL);
drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
type_str, ptr);
for (i = 0; i < history->len; i++) {
const struct drm_dp_mst_topology_ref_entry *entry =
&history->entries[i];
ulong *entries;
uint nr_entries;
u64 ts_nsec = entry->ts_nsec;
u32 rem_nsec = do_div(ts_nsec, 1000000000);
nr_entries = stack_depot_fetch(entry->backtrace, &entries);
stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
entry->count,
topology_ref_type_to_str(entry->type),
ts_nsec, rem_nsec / 1000, buf);
}
/* Now free the history, since this is the only time we expose it */
kfree(history->entries);
out:
kfree(buf);
}
static __always_inline void
drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
{
__dump_topology_ref_history(&mstb->topology_ref_history, mstb,
"MSTB");
}
static __always_inline void
drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
{
__dump_topology_ref_history(&port->topology_ref_history, port,
"Port");
}
static __always_inline void
save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
enum drm_dp_mst_topology_ref_type type)
{
__topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
}
static __always_inline void
save_port_topology_ref(struct drm_dp_mst_port *port,
enum drm_dp_mst_topology_ref_type type)
{
__topology_ref_save(port->mgr, &port->topology_ref_history, type);
}
static inline void
topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->topology_ref_history_lock);
}
static inline void
topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_unlock(&mgr->topology_ref_history_lock);
}
#else
static inline void
topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
static inline void
topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
static inline void
drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
static inline void
drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
#define save_mstb_topology_ref(mstb, type)
#define save_port_topology_ref(port, type)
#endif
static void drm_dp_destroy_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb =
container_of(kref, struct drm_dp_mst_branch, topology_kref);
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
drm_dp_mst_dump_mstb_topology_history(mstb);
INIT_LIST_HEAD(&mstb->destroy_next);
/*
* This can get called under mgr->mutex, so we need to perform the
* actual destruction of the mstb in another worker
*/
mutex_lock(&mgr->delayed_destroy_lock);
list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
mutex_unlock(&mgr->delayed_destroy_lock);
queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
}
/**
* drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
* branch device unless it's zero
* @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
*
* Attempts to grab a topology reference to @mstb, if it hasn't yet been
* removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
* reached 0). Holding a topology reference implies that a malloc reference
* will be held to @mstb as long as the user holds the topology reference.
*
* Care should be taken to ensure that the user has at least one malloc
* reference to @mstb. If you already have a topology reference to @mstb, you
* should use drm_dp_mst_topology_get_mstb() instead.
*
* See also:
* drm_dp_mst_topology_get_mstb()
* drm_dp_mst_topology_put_mstb()
*
* Returns:
* * 1: A topology reference was grabbed successfully
* * 0: @port is no longer in the topology, no reference was grabbed
*/
static int __must_check
drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
{
int ret;
topology_ref_history_lock(mstb->mgr);
ret = kref_get_unless_zero(&mstb->topology_kref);
if (ret) {
DRM_DEBUG("mstb %p (%d)\n",
mstb, kref_read(&mstb->topology_kref));
save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
}
topology_ref_history_unlock(mstb->mgr);
return ret;
}
/**
* drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
* branch device
* @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
*
* Increments &drm_dp_mst_branch.topology_refcount without checking whether or
* not it's already reached 0. This is only valid to use in scenarios where
* you are already guaranteed to have at least one active topology reference
* to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
*
* See also:
* drm_dp_mst_topology_try_get_mstb()
* drm_dp_mst_topology_put_mstb()
*/
static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
{
topology_ref_history_lock(mstb->mgr);
save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
WARN_ON(kref_read(&mstb->topology_kref) == 0);
kref_get(&mstb->topology_kref);
DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
topology_ref_history_unlock(mstb->mgr);
}
/**
* drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
* device
* @mstb: The &struct drm_dp_mst_branch to release the topology reference from
*
* Releases a topology reference from @mstb by decrementing
* &drm_dp_mst_branch.topology_kref.
*
* See also:
* drm_dp_mst_topology_try_get_mstb()
* drm_dp_mst_topology_get_mstb()
*/
static void
drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
{
topology_ref_history_lock(mstb->mgr);
DRM_DEBUG("mstb %p (%d)\n",
mstb, kref_read(&mstb->topology_kref) - 1);
save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
topology_ref_history_unlock(mstb->mgr);
kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
}
static void drm_dp_destroy_port(struct kref *kref)
{
struct drm_dp_mst_port *port =
container_of(kref, struct drm_dp_mst_port, topology_kref);
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
drm_dp_mst_dump_port_topology_history(port);
/* There's nothing that needs locking to destroy an input port yet */
if (port->input) {
drm_dp_mst_put_port_malloc(port);
return;
}
kfree(port->cached_edid);
/*
* we can't destroy the connector here, as we might be holding the
* mode_config.mutex from an EDID retrieval
*/
mutex_lock(&mgr->delayed_destroy_lock);
list_add(&port->next, &mgr->destroy_port_list);
mutex_unlock(&mgr->delayed_destroy_lock);
queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
}
/**
* drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
* port unless it's zero
* @port: &struct drm_dp_mst_port to increment the topology refcount of
*
* Attempts to grab a topology reference to @port, if it hasn't yet been
* removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
* 0). Holding a topology reference implies that a malloc reference will be
* held to @port as long as the user holds the topology reference.
*
* Care should be taken to ensure that the user has at least one malloc
* reference to @port. If you already have a topology reference to @port, you
* should use drm_dp_mst_topology_get_port() instead.
*
* See also:
* drm_dp_mst_topology_get_port()
* drm_dp_mst_topology_put_port()
*
* Returns:
* * 1: A topology reference was grabbed successfully
* * 0: @port is no longer in the topology, no reference was grabbed
*/
static int __must_check
drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
{
int ret;
topology_ref_history_lock(port->mgr);
ret = kref_get_unless_zero(&port->topology_kref);
if (ret) {
DRM_DEBUG("port %p (%d)\n",
port, kref_read(&port->topology_kref));
save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
}
topology_ref_history_unlock(port->mgr);
return ret;
}
/**
* drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
* @port: The &struct drm_dp_mst_port to increment the topology refcount of
*
* Increments &drm_dp_mst_port.topology_refcount without checking whether or
* not it's already reached 0. This is only valid to use in scenarios where
* you are already guaranteed to have at least one active topology reference
* to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
*
* See also:
* drm_dp_mst_topology_try_get_port()
* drm_dp_mst_topology_put_port()
*/
static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
{
topology_ref_history_lock(port->mgr);
WARN_ON(kref_read(&port->topology_kref) == 0);
kref_get(&port->topology_kref);
DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
topology_ref_history_unlock(port->mgr);
}
/**
* drm_dp_mst_topology_put_port() - release a topology reference to a port
* @port: The &struct drm_dp_mst_port to release the topology reference from
*
* Releases a topology reference from @port by decrementing
* &drm_dp_mst_port.topology_kref.
*
* See also:
* drm_dp_mst_topology_try_get_port()
* drm_dp_mst_topology_get_port()
*/
static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
{
topology_ref_history_lock(port->mgr);
DRM_DEBUG("port %p (%d)\n",
port, kref_read(&port->topology_kref) - 1);
save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
topology_ref_history_unlock(port->mgr);
kref_put(&port->topology_kref, drm_dp_destroy_port);
}
static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_branch *to_find)
{
struct drm_dp_mst_port *port;
struct drm_dp_mst_branch *rmstb;
if (to_find == mstb)
return mstb;
list_for_each_entry(port, &mstb->ports, next) {
if (port->mstb) {
rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
port->mstb, to_find);
if (rmstb)
return rmstb;
}
}
return NULL;
}
static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_branch *rmstb = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
mgr->mst_primary, mstb);
if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
rmstb = NULL;
}
mutex_unlock(&mgr->lock);
return rmstb;
}
static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *to_find)
{
struct drm_dp_mst_port *port, *mport;
list_for_each_entry(port, &mstb->ports, next) {
if (port == to_find)
return port;
if (port->mstb) {
mport = drm_dp_mst_topology_get_port_validated_locked(
port->mstb, to_find);
if (mport)
return mport;
}
}
return NULL;
}
static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_port *rport = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
rport = drm_dp_mst_topology_get_port_validated_locked(
mgr->mst_primary, port);
if (rport && !drm_dp_mst_topology_try_get_port(rport))
rport = NULL;
}
mutex_unlock(&mgr->lock);
return rport;
}
static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
{
struct drm_dp_mst_port *port;
int ret;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
ret = drm_dp_mst_topology_try_get_port(port);
return ret ? port : NULL;
}
}
return NULL;
}
/*
* calculate a new RAD for this MST branch device
* if parent has an LCT of 2 then it has 1 nibble of RAD,
* if parent has an LCT of 3 then it has 2 nibbles of RAD,
*/
static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
u8 *rad)
{
int parent_lct = port->parent->lct;
int shift = 4;
int idx = (parent_lct - 1) / 2;
if (parent_lct > 1) {
memcpy(rad, port->parent->rad, idx + 1);
shift = (parent_lct % 2) ? 4 : 0;
} else
rad[0] = 0;
rad[idx] |= port->port_num << shift;
return parent_lct + 1;
}
static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
{
switch (pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
case DP_PEER_DEVICE_SST_SINK:
return true;
case DP_PEER_DEVICE_MST_BRANCHING:
/* For sst branch device */
if (!mcs)
return true;
return false;
}
return true;
}
static int
drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
bool new_mcs)
{
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
struct drm_dp_mst_branch *mstb;
u8 rad[8], lct;
int ret = 0;
if (port->pdt == new_pdt && port->mcs == new_mcs)
return 0;
/* Teardown the old pdt, if there is one */
if (port->pdt != DP_PEER_DEVICE_NONE) {
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
/*
* If the new PDT would also have an i2c bus,
* don't bother with reregistering it
*/
if (new_pdt != DP_PEER_DEVICE_NONE &&
drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
port->pdt = new_pdt;
port->mcs = new_mcs;
return 0;
}
/* remove i2c over sideband */
drm_dp_mst_unregister_i2c_bus(port);
} else {
mutex_lock(&mgr->lock);
drm_dp_mst_topology_put_mstb(port->mstb);
port->mstb = NULL;
mutex_unlock(&mgr->lock);
}
}
port->pdt = new_pdt;
port->mcs = new_mcs;
if (port->pdt != DP_PEER_DEVICE_NONE) {
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
/* add i2c over sideband */
ret = drm_dp_mst_register_i2c_bus(port);
} else {
lct = drm_dp_calculate_rad(port, rad);
mstb = drm_dp_add_mst_branch_device(lct, rad);
if (!mstb) {
ret = -ENOMEM;
DRM_ERROR("Failed to create MSTB for port %p",
port);
goto out;
}
mutex_lock(&mgr->lock);
port->mstb = mstb;
mstb->mgr = port->mgr;
mstb->port_parent = port;
/*
* Make sure this port's memory allocation stays
* around until its child MSTB releases it
*/
drm_dp_mst_get_port_malloc(port);
mutex_unlock(&mgr->lock);
/* And make sure we send a link address for this */
ret = 1;
}
}
out:
if (ret < 0)
port->pdt = DP_PEER_DEVICE_NONE;
return ret;
}
/**
* drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
* @aux: Fake sideband AUX CH
* @offset: address of the (first) register to read
* @buffer: buffer to store the register values
* @size: number of bytes in @buffer
*
* Performs the same functionality for remote devices via
* sideband messaging as drm_dp_dpcd_read() does for local
* devices via actual AUX CH.
*
* Return: Number of bytes read, or negative error code on failure.
*/
ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
aux);
return drm_dp_send_dpcd_read(port->mgr, port,
offset, size, buffer);
}
/**
* drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
* @aux: Fake sideband AUX CH
* @offset: address of the (first) register to write
* @buffer: buffer containing the values to write
* @size: number of bytes in @buffer
*
* Performs the same functionality for remote devices via
* sideband messaging as drm_dp_dpcd_write() does for local
* devices via actual AUX CH.
*
* Return: number of bytes written on success, negative error code on failure.
*/
ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
aux);
return drm_dp_send_dpcd_write(port->mgr, port,
offset, size, buffer);
}
static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
{
int ret = 0;
memcpy(mstb->guid, guid, 16);
if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
if (mstb->port_parent) {
ret = drm_dp_send_dpcd_write(mstb->mgr,
mstb->port_parent,
DP_GUID, 16, mstb->guid);
} else {
ret = drm_dp_dpcd_write(mstb->mgr->aux,
DP_GUID, mstb->guid, 16);
}
}
if (ret < 16 && ret > 0)
return -EPROTO;
return ret == 16 ? 0 : ret;
}
static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
int pnum,
char *proppath,
size_t proppath_size)
{
int i;
char temp[8];
snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
for (i = 0; i < (mstb->lct - 1); i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
snprintf(temp, sizeof(temp), "-%d", port_num);
strlcat(proppath, temp, proppath_size);
}
snprintf(temp, sizeof(temp), "-%d", pnum);
strlcat(proppath, temp, proppath_size);
}
/**
* drm_dp_mst_connector_late_register() - Late MST connector registration
* @connector: The MST connector
* @port: The MST port for this connector
*
* Helper to register the remote aux device for this MST port. Drivers should
* call this from their mst connector's late_register hook to enable MST aux
* devices.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_dp_mst_connector_late_register(struct drm_connector *connector,
struct drm_dp_mst_port *port)
{
DRM_DEBUG_KMS("registering %s remote bus for %s\n",
port->aux.name, connector->kdev->kobj.name);
port->aux.dev = connector->kdev;
return drm_dp_aux_register_devnode(&port->aux);
}
EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
/**
* drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
* @connector: The MST connector
* @port: The MST port for this connector
*
* Helper to unregister the remote aux device for this MST port, registered by
* drm_dp_mst_connector_late_register(). Drivers should call this from their mst
* connector's early_unregister hook.
*/
void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
struct drm_dp_mst_port *port)
{
DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
port->aux.name, connector->kdev->kobj.name);
drm_dp_aux_unregister_devnode(&port->aux);
}
EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
static void
drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
char proppath[255];
int ret;
build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
port->connector = mgr->cbs->add_connector(mgr, port, proppath);
if (!port->connector) {
ret = -ENOMEM;
goto error;
}
if (port->pdt != DP_PEER_DEVICE_NONE &&
drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
port->cached_edid = drm_get_edid(port->connector,
&port->aux.ddc);
drm_connector_set_tile_property(port->connector);
}
drm_connector_register(port->connector);
return;
error:
DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
}
/*
* Drop a topology reference, and unlink the port from the in-memory topology
* layout
*/
static void
drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
mutex_lock(&mgr->lock);
port->parent->num_ports--;
list_del(&port->next);
mutex_unlock(&mgr->lock);
drm_dp_mst_topology_put_port(port);
}
static struct drm_dp_mst_port *
drm_dp_mst_add_port(struct drm_device *dev,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb, u8 port_number)
{
struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port)
return NULL;
kref_init(&port->topology_kref);
kref_init(&port->malloc_kref);
port->parent = mstb;
port->port_num = port_number;
port->mgr = mgr;
port->aux.name = "DPMST";
port->aux.dev = dev->dev;
port->aux.is_remote = true;
/* initialize the MST downstream port's AUX crc work queue */
drm_dp_remote_aux_init(&port->aux);
/*
* Make sure the memory allocation for our parent branch stays
* around until our own memory allocation is released
*/
drm_dp_mst_get_mstb_malloc(mstb);
return port;
}
static int
drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
struct drm_device *dev,
struct drm_dp_link_addr_reply_port *port_msg)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port;
int old_ddps = 0, ret;
u8 new_pdt = DP_PEER_DEVICE_NONE;
bool new_mcs = 0;
bool created = false, send_link_addr = false, changed = false;
port = drm_dp_get_port(mstb, port_msg->port_number);
if (!port) {
port = drm_dp_mst_add_port(dev, mgr, mstb,
port_msg->port_number);
if (!port)
return -ENOMEM;
created = true;
changed = true;
} else if (!port->input && port_msg->input_port && port->connector) {
/* Since port->connector can't be changed here, we create a
* new port if input_port changes from 0 to 1
*/
drm_dp_mst_topology_unlink_port(mgr, port);
drm_dp_mst_topology_put_port(port);
port = drm_dp_mst_add_port(dev, mgr, mstb,
port_msg->port_number);
if (!port)
return -ENOMEM;
changed = true;
created = true;
} else if (port->input && !port_msg->input_port) {
changed = true;
} else if (port->connector) {
/* We're updating a port that's exposed to userspace, so do it
* under lock
*/
drm_modeset_lock(&mgr->base.lock, NULL);
old_ddps = port->ddps;
changed = port->ddps != port_msg->ddps ||
(port->ddps &&
(port->ldps != port_msg->legacy_device_plug_status ||
port->dpcd_rev != port_msg->dpcd_revision ||
port->mcs != port_msg->mcs ||
port->pdt != port_msg->peer_device_type ||
port->num_sdp_stream_sinks !=
port_msg->num_sdp_stream_sinks));
}
port->input = port_msg->input_port;
if (!port->input)
new_pdt = port_msg->peer_device_type;
new_mcs = port_msg->mcs;
port->ddps = port_msg->ddps;
port->ldps = port_msg->legacy_device_plug_status;
port->dpcd_rev = port_msg->dpcd_revision;
port->num_sdp_streams = port_msg->num_sdp_streams;
port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
/* manage mstb port lists with mgr lock - take a reference
for this list */
if (created) {
mutex_lock(&mgr->lock);
drm_dp_mst_topology_get_port(port);
list_add(&port->next, &mstb->ports);
mstb->num_ports++;
mutex_unlock(&mgr->lock);
}
/*
* Reprobe PBN caps on both hotplug, and when re-probing the link
* for our parent mstb
*/
if (old_ddps != port->ddps || !created) {
if (port->ddps && !port->input) {
ret = drm_dp_send_enum_path_resources(mgr, mstb,
port);
if (ret == 1)
changed = true;
} else {
port->full_pbn = 0;
}
}
ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
send_link_addr = true;
} else if (ret < 0) {
DRM_ERROR("Failed to change PDT on port %p: %d\n",
port, ret);
goto fail;
}
/*
* If this port wasn't just created, then we're reprobing because
* we're coming out of suspend. In this case, always resend the link
* address if there's an MSTB on this port
*/
if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
port->mcs)
send_link_addr = true;
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
else if (!port->input)
drm_dp_mst_port_add_connector(mstb, port);
if (send_link_addr && port->mstb) {
ret = drm_dp_send_link_address(mgr, port->mstb);
if (ret == 1) /* MSTB below us changed */
changed = true;
else if (ret < 0)
goto fail_put;
}
/* put reference to this port */
drm_dp_mst_topology_put_port(port);
return changed;
fail:
drm_dp_mst_topology_unlink_port(mgr, port);
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
fail_put:
drm_dp_mst_topology_put_port(port);
return ret;
}
static void
drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
struct drm_dp_connection_status_notify *conn_stat)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port;
int old_ddps, old_input, ret, i;
u8 new_pdt;
bool new_mcs;
bool dowork = false, create_connector = false;
port = drm_dp_get_port(mstb, conn_stat->port_number);
if (!port)
return;
if (port->connector) {
if (!port->input && conn_stat->input_port) {
/*
* We can't remove a connector from an already exposed
* port, so just throw the port out and make sure we
* reprobe the link address of it's parent MSTB
*/
drm_dp_mst_topology_unlink_port(mgr, port);
mstb->link_address_sent = false;
dowork = true;
goto out;
}
/* Locking is only needed if the port's exposed to userspace */
drm_modeset_lock(&mgr->base.lock, NULL);
} else if (port->input && !conn_stat->input_port) {
create_connector = true;
/* Reprobe link address so we get num_sdp_streams */
mstb->link_address_sent = false;
dowork = true;
}
old_ddps = port->ddps;
old_input = port->input;
port->input = conn_stat->input_port;
port->ldps = conn_stat->legacy_device_plug_status;
port->ddps = conn_stat->displayport_device_plug_status;
if (old_ddps != port->ddps) {
if (port->ddps && !port->input)
drm_dp_send_enum_path_resources(mgr, mstb, port);
else
port->full_pbn = 0;
}
new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
new_mcs = conn_stat->message_capability_status;
ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
dowork = true;
} else if (ret < 0) {
DRM_ERROR("Failed to change PDT for port %p: %d\n",
port, ret);
dowork = false;
}
if (!old_input && old_ddps != port->ddps && !port->ddps) {
for (i = 0; i < mgr->max_payloads; i++) {
struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
struct drm_dp_mst_port *port_validated;
if (!vcpi)
continue;
port_validated =
container_of(vcpi, struct drm_dp_mst_port, vcpi);
port_validated =
drm_dp_mst_topology_get_port_validated(mgr, port_validated);
if (!port_validated) {
mutex_lock(&mgr->payload_lock);
vcpi->num_slots = 0;
mutex_unlock(&mgr->payload_lock);
} else {
drm_dp_mst_topology_put_port(port_validated);
}
}
}
if (port->connector)
drm_modeset_unlock(&mgr->base.lock);
else if (create_connector)
drm_dp_mst_port_add_connector(mstb, port);
out:
drm_dp_mst_topology_put_port(port);
if (dowork)
queue_work(system_long_wq, &mstb->mgr->work);
}
static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_port *port;
int i, ret;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = mgr->mst_primary;
if (!mstb)
goto out;
for (i = 0; i < lct - 1; i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = (rad[i / 2] >> shift) & 0xf;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
mstb = port->mstb;
if (!mstb) {
DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
goto out;
}
break;
}
}
}
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
out:
mutex_unlock(&mgr->lock);
return mstb;
}
static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
struct drm_dp_mst_branch *mstb,
const uint8_t *guid)
{
struct drm_dp_mst_branch *found_mstb;
struct drm_dp_mst_port *port;
if (memcmp(mstb->guid, guid, 16) == 0)
return mstb;
list_for_each_entry(port, &mstb->ports, next) {
if (!port->mstb)
continue;
found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
if (found_mstb)
return found_mstb;
}
return NULL;
}
static struct drm_dp_mst_branch *
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
const uint8_t *guid)
{
struct drm_dp_mst_branch *mstb;
int ret;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
if (mstb) {
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
}
mutex_unlock(&mgr->lock);
return mstb;
}
static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
int ret;
bool changed = false;
if (!mstb->link_address_sent) {
ret = drm_dp_send_link_address(mgr, mstb);
if (ret == 1)
changed = true;
else if (ret < 0)
return ret;
}
list_for_each_entry(port, &mstb->ports, next) {
struct drm_dp_mst_branch *mstb_child = NULL;
if (port->input || !port->ddps)
continue;
if (port->mstb)
mstb_child = drm_dp_mst_topology_get_mstb_validated(
mgr, port->mstb);
if (mstb_child) {
ret = drm_dp_check_and_send_link_address(mgr,
mstb_child);
drm_dp_mst_topology_put_mstb(mstb_child);
if (ret == 1)
changed = true;
else if (ret < 0)
return ret;
}
}
return changed;
}
static void drm_dp_mst_link_probe_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr =
container_of(work, struct drm_dp_mst_topology_mgr, work);
struct drm_device *dev = mgr->dev;
struct drm_dp_mst_branch *mstb;
int ret;
bool clear_payload_id_table;
mutex_lock(&mgr->probe_lock);
mutex_lock(&mgr->lock);
clear_payload_id_table = !mgr->payload_id_table_cleared;
mgr->payload_id_table_cleared = true;
mstb = mgr->mst_primary;
if (mstb) {
ret = drm_dp_mst_topology_try_get_mstb(mstb);
if (!ret)
mstb = NULL;
}
mutex_unlock(&mgr->lock);
if (!mstb) {
mutex_unlock(&mgr->probe_lock);
return;
}
/*
* Certain branch devices seem to incorrectly report an available_pbn
* of 0 on downstream sinks, even after clearing the
* DP_PAYLOAD_ALLOCATE_* registers in
* drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
* 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
* things work again.
*/
if (clear_payload_id_table) {
DRM_DEBUG_KMS("Clearing payload ID table\n");
drm_dp_send_clear_payload_id_table(mgr, mstb);
}
ret = drm_dp_check_and_send_link_address(mgr, mstb);
drm_dp_mst_topology_put_mstb(mstb);
mutex_unlock(&mgr->probe_lock);
if (ret)
drm_kms_helper_hotplug_event(dev);
}
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid)
{
u64 salt;
if (memchr_inv(guid, 0, 16))
return true;
salt = get_jiffies_64();
memcpy(&guid[0], &salt, sizeof(u64));
memcpy(&guid[8], &salt, sizeof(u64));
return false;
}
static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
u8 port_num, u32 offset, u8 num_bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_READ;
req.u.dpcd_read.port_number = port_num;
req.u.dpcd_read.dpcd_address = offset;
req.u.dpcd_read.num_bytes = num_bytes;
drm_dp_encode_sideband_req(&req, msg);
}
static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
bool up, u8 *msg, int len)
{
int ret;
int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
int tosend, total, offset;
int retries = 0;
retry:
total = len;
offset = 0;
do {
tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
&msg[offset],
tosend);
if (ret != tosend) {
if (ret == -EIO && retries < 5) {
retries++;
goto retry;
}
DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
return -EIO;
}
offset += tosend;
total -= tosend;
} while (total > 0);
return 0;
}
static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_branch *mstb = txmsg->dst;
u8 req_type;
req_type = txmsg->msg[0] & 0x7f;
if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
req_type == DP_RESOURCE_STATUS_NOTIFY)
hdr->broadcast = 1;
else
hdr->broadcast = 0;
hdr->path_msg = txmsg->path_msg;
hdr->lct = mstb->lct;
hdr->lcr = mstb->lct - 1;
if (mstb->lct > 1)
memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
return 0;
}
/*
* process a single block of the next message in the sideband queue
*/
static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg,
bool up)
{
u8 chunk[48];
struct drm_dp_sideband_msg_hdr hdr;
int len, space, idx, tosend;
int ret;
if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
return 0;
memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
/* make hdr from dst mst */
ret = set_hdr_from_dst_qlock(&hdr, txmsg);
if (ret < 0)
return ret;
/* amount left to send in this message */
len = txmsg->cur_len - txmsg->cur_offset;
/* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
tosend = min(len, space);
if (len == txmsg->cur_len)
hdr.somt = 1;
if (space >= len)
hdr.eomt = 1;
hdr.msg_len = tosend + 1;
drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
/* add crc at end */
drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
idx += tosend + 1;
ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_printf(&p, "sideband msg failed to send\n");
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
return ret;
}
txmsg->cur_offset += tosend;
if (txmsg->cur_offset == txmsg->cur_len) {
txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
return 1;
}
return 0;
}
static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
WARN_ON(!mutex_is_locked(&mgr->qlock));
/* construct a chunk from the first msg in the tx_msg queue */
if (list_empty(&mgr->tx_msg_downq))
return;
txmsg = list_first_entry(&mgr->tx_msg_downq,
struct drm_dp_sideband_msg_tx, next);
ret = process_single_tx_qlock(mgr, txmsg, false);
if (ret < 0) {
DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
list_del(&txmsg->next);
txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
wake_up_all(&mgr->tx_waitq);
}
}
static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
mutex_lock(&mgr->qlock);
list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
if (drm_debug_enabled(DRM_UT_DP)) {
struct drm_printer p = drm_debug_printer(DBG_PREFIX);
drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
}
if (list_is_singular(&mgr->tx_msg_downq))
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
static void
drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
{
struct drm_dp_link_addr_reply_port *port_reply;
int i;
for (i = 0; i < reply->nports; i++) {
port_reply = &reply->ports[i];
DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
i,
port_reply->input_port,
port_reply->peer_device_type,
port_reply->port_number,
port_reply->dpcd_revision,
port_reply->mcs,
port_reply->ddps,
port_reply->legacy_device_plug_status,
port_reply->num_sdp_streams,
port_reply->num_sdp_stream_sinks);
}
}
static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_link_address_ack_reply *reply;
struct drm_dp_mst_port *port, *tmp;
int i, ret, port_mask = 0;
bool changed = false;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
build_link_address(txmsg);
mstb->link_address_sent = true;
drm_dp_queue_down_tx(mgr, txmsg);
/* FIXME: Actually do some real error handling here */
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret <= 0) {
DRM_ERROR("Sending link address failed with %d\n", ret);
goto out;
}
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
DRM_ERROR("link address NAK received\n");
ret = -EIO;
goto out;
}
reply = &txmsg->reply.u.link_addr;
DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
drm_dp_dump_link_address(reply);
ret = drm_dp_check_mstb_guid(mstb, reply->guid);
if (ret) {
char buf[64];
drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
DRM_ERROR("GUID check on %s failed: %d\n",
buf, ret);
goto out;
}
for (i = 0; i < reply->nports; i++) {
port_mask |= BIT(reply->ports[i].port_number);
ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
&reply->ports[i]);
if (ret == 1)
changed = true;
else if (ret < 0)
goto out;
}
/* Prune any ports that are currently a part of mstb in our in-memory
* topology, but were not seen in this link address. Usually this
* means that they were removed while the topology was out of sync,
* e.g. during suspend/resume
*/
mutex_lock(&mgr->lock);
list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
if (port_mask & BIT(port->port_num))
continue;
DRM_DEBUG_KMS("port %d was not in link address, removing\n",
port->port_num);
list_del(&port->next);
drm_dp_mst_topology_put_port(port);
changed = true;
}
mutex_unlock(&mgr->lock);
out:
if (ret <= 0)
mstb->link_address_sent = false;
kfree(txmsg);
return ret < 0 ? ret : changed;
}
static void
drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return;
txmsg->dst = mstb;
build_clear_payload_id_table(txmsg);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
DRM_DEBUG_KMS("clear payload table id nak received\n");
kfree(txmsg);
}
static int
drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
{
struct drm_dp_enum_path_resources_ack_reply *path_res;
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
build_enum_path_resources(txmsg, port->port_num);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
ret = 0;
path_res = &txmsg->reply.u.path_resources;
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
DRM_DEBUG_KMS("enum path resources nak received\n");
} else {
if (port->port_num != path_res->port_number)
DRM_ERROR("got incorrect port in response\n");
DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
path_res->port_number,
path_res->full_payload_bw_number,
path_res->avail_payload_bw_number);
/*
* If something changed, make sure we send a
* hotplug
*/
if (port->full_pbn != path_res->full_payload_bw_number ||
port->fec_capable != path_res->fec_capable)
ret = 1;
port->full_pbn = path_res->full_payload_bw_number;
port->fec_capable = path_res->fec_capable;
}
}
kfree(txmsg);
return ret;
}
static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
{
if (!mstb->port_parent)
return NULL;
if (mstb->port_parent->mstb != mstb)
return mstb->port_parent;
return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
}
/*
* Searches upwards in the topology starting from mstb to try to find the
* closest available parent of mstb that's still connected to the rest of the
* topology. This can be used in order to perform operations like releasing
* payloads, where the branch device which owned the payload may no longer be
* around and thus would require that the payload on the last living relative
* be freed instead.
*/
static struct drm_dp_mst_branch *
drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
int *port_num)
{
struct drm_dp_mst_branch *rmstb = NULL;
struct drm_dp_mst_port *found_port;
mutex_lock(&mgr->lock);
if (!mgr->mst_primary)
goto out;
do {
found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
if (!found_port)
break;
if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
rmstb = found_port->parent;
*port_num = found_port->port_num;
} else {
/* Search again, starting from this parent */
mstb = found_port->parent;
}
} while (!rmstb);
out:
mutex_unlock(&mgr->lock);
return rmstb;
}
static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
int pbn)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
int ret, port_num;
u8 sinks[DRM_DP_MAX_SDP_STREAMS];
int i;
port_num = port->port_num;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb) {
mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
port->parent,
&port_num);
if (!mstb)
return -EINVAL;
}
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
for (i = 0; i < port->num_sdp_streams; i++)
sinks[i] = i;
txmsg->dst = mstb;
build_allocate_payload(txmsg, port_num,
id,
pbn, port->num_sdp_streams, sinks);
drm_dp_queue_down_tx(mgr, txmsg);
/*
* FIXME: there is a small chance that between getting the last
* connected mstb and sending the payload message, the last connected
* mstb could also be removed from the topology. In the future, this
* needs to be fixed by restarting the
* drm_dp_get_last_connected_port_and_mstb() search in the event of a
* timeout if the topology is still connected to the system.
*/
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ret = -EINVAL;
else
ret = 0;
}
kfree(txmsg);
fail_put:
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, bool power_up)
{
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
drm_dp_mst_topology_put_port(port);
return -ENOMEM;
}
txmsg->dst = port->parent;
build_power_updown_phy(txmsg, port->port_num, power_up);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ret = -EINVAL;
else
ret = 0;
}
kfree(txmsg);
drm_dp_mst_topology_put_port(port);
return ret;
}
EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload)
{
int ret;
ret = drm_dp_dpcd_write_payload(mgr, id, payload);
if (ret < 0) {
payload->payload_state = 0;
return ret;
}
payload->payload_state = DP_PAYLOAD_LOCAL;
return 0;
}
static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
struct drm_dp_payload *payload)
{
int ret;
ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
if (ret < 0)
return ret;
payload->payload_state = DP_PAYLOAD_REMOTE;
return ret;
}
static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
struct drm_dp_payload *payload)
{
DRM_DEBUG_KMS("\n");
/* it's okay for these to fail */
if (port) {
drm_dp_payload_send_msg(mgr, port, id, 0);
}
drm_dp_dpcd_write_payload(mgr, id, payload);
payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
return 0;
}
static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload)
{
payload->payload_state = 0;
return 0;
}
/**
* drm_dp_update_payload_part1() - Execute payload update part 1
* @mgr: manager to use.
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
* this step just writes the VCPI to the MST device. For slots->0
* transitions, this writes the updated VCPIs and removes the
* remote VC payloads.
*
* after calling this the driver should generate ACT and payload
* packets.
*/
int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_payload req_payload;
struct drm_dp_mst_port *port;
int i, j;
int cur_slots = 1;
mutex_lock(&mgr->payload_lock);
for (i = 0; i < mgr->max_payloads; i++) {
struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
struct drm_dp_payload *payload = &mgr->payloads[i];
bool put_port = false;
/* solve the current payloads - compare to the hw ones
- update the hw view */
req_payload.start_slot = cur_slots;
if (vcpi) {
port = container_of(vcpi, struct drm_dp_mst_port,
vcpi);
/* Validated ports don't matter if we're releasing
* VCPI
*/
if (vcpi->num_slots) {
port = drm_dp_mst_topology_get_port_validated(
mgr, port);
if (!port) {
mutex_unlock(&mgr->payload_lock);
return -EINVAL;
}
put_port = true;
}
req_payload.num_slots = vcpi->num_slots;
req_payload.vcpi = vcpi->vcpi;
} else {
port = NULL;
req_payload.num_slots = 0;
}
payload->start_slot = req_payload.start_slot;
/* work out what is required to happen with this payload */
if (payload->num_slots != req_payload.num_slots) {
/* need to push an update for this payload */
if (req_payload.num_slots) {
drm_dp_create_payload_step1(mgr, vcpi->vcpi,
&req_payload);
payload->num_slots = req_payload.num_slots;
payload->vcpi = req_payload.vcpi;
} else if (payload->num_slots) {
payload->num_slots = 0;
drm_dp_destroy_payload_step1(mgr, port,
payload->vcpi,
payload);
req_payload.payload_state =
payload->payload_state;
payload->start_slot = 0;
}
payload->payload_state = req_payload.payload_state;
}
cur_slots += req_payload.num_slots;
if (put_port)
drm_dp_mst_topology_put_port(port);
}
for (i = 0; i < mgr->max_payloads; /* do nothing */) {
if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
i++;
continue;
}
DRM_DEBUG_KMS("removing payload %d\n", i);
for (j = i; j < mgr->max_payloads - 1; j++) {
mgr->payloads[j] = mgr->payloads[j + 1];
mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
if (mgr->proposed_vcpis[j] &&
mgr->proposed_vcpis[j]->num_slots) {
set_bit(j + 1, &mgr->payload_mask);
} else {
clear_bit(j + 1, &mgr->payload_mask);
}
}
memset(&mgr->payloads[mgr->max_payloads - 1], 0,
sizeof(struct drm_dp_payload));
mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
clear_bit(mgr->max_payloads, &mgr->payload_mask);
}
mutex_unlock(&mgr->payload_lock);
return 0;
}
EXPORT_SYMBOL(drm_dp_update_payload_part1);
/**
* drm_dp_update_payload_part2() - Execute payload update part 2
* @mgr: manager to use.
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
* this step writes the remote VC payload commands. For slots->0
* this just resets some internal state.
*/
int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_mst_port *port;
int i;
int ret = 0;
mutex_lock(&mgr->payload_lock);
for (i = 0; i < mgr->max_payloads; i++) {
if (!mgr->proposed_vcpis[i])
continue;
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
} else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
}
if (ret) {
mutex_unlock(&mgr->payload_lock);
return ret;
}
}
mutex_unlock(&mgr->payload_lock);
return 0;
}
EXPORT_SYMBOL(drm_dp_update_payload_part2);
static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes)
{
int ret = 0;
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
build_dpcd_read(txmsg, port->port_num, offset, size);
txmsg->dst = port->parent;
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret < 0)
goto fail_free;
/* DPCD read should never be NACKed */
if (txmsg->reply.reply_type == 1) {
DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
mstb, port->port_num, offset, size);
ret = -EIO;
goto fail_free;
}
if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
ret = -EPROTO;
goto fail_free;
}
ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
size);
memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
fail_free:
kfree(txmsg);
fail_put:
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes)
{
int ret;
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
txmsg->dst = mstb;
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ret = -EIO;
else
ret = size;
}
kfree(txmsg);
fail_put:
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
{
struct drm_dp_sideband_msg_reply_body reply;
reply.reply_type = DP_SIDEBAND_REPLY_ACK;
reply.req_type = req_type;
drm_dp_encode_sideband_reply(&reply, msg);
return 0;
}
static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
int req_type, bool broadcast)
{
struct drm_dp_sideband_msg_tx *txmsg;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
drm_dp_encode_up_ack_reply(txmsg, req_type);
mutex_lock(&mgr->qlock);
/* construct a chunk from the first msg in the tx_msg queue */
process_single_tx_qlock(mgr, txmsg, true);
mutex_unlock(&mgr->qlock);
kfree(txmsg);
return 0;
}
static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
{
if (dp_link_bw == 0 || dp_link_count == 0)
DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
dp_link_bw, dp_link_count);
return dp_link_bw * dp_link_count / 2;
}
/**
* drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
* @mgr: manager to set state for
* @mst_state: true to enable MST on this connector - false to disable.
*
* This is called by the driver when it detects an MST capable device plugged
* into a DP MST capable port, or when a DP MST capable device is unplugged.
*/
int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
{
int ret = 0;
struct drm_dp_mst_branch *mstb = NULL;
mutex_lock(&mgr->payload_lock);
mutex_lock(&mgr->lock);
if (mst_state == mgr->mst_state)
goto out_unlock;
mgr->mst_state = mst_state;
/* set the device into MST mode */
if (mst_state) {
struct drm_dp_payload reset_pay;
WARN_ON(mgr->mst_primary);
/* get dpcd info */
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (ret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("failed to read DPCD\n");
goto out_unlock;
}
mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
if (mgr->pbn_div == 0) {
ret = -EINVAL;
goto out_unlock;
}
/* add initial branch device at LCT 1 */
mstb = drm_dp_add_mst_branch_device(1, NULL);
if (mstb == NULL) {
ret = -ENOMEM;
goto out_unlock;
}
mstb->mgr = mgr;
/* give this the main reference */
mgr->mst_primary = mstb;
drm_dp_mst_topology_get_mstb(mgr->mst_primary);
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN |
DP_UP_REQ_EN |
DP_UPSTREAM_IS_SRC);
if (ret < 0)
goto out_unlock;
reset_pay.start_slot = 0;
reset_pay.num_slots = 0x3f;
drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
queue_work(system_long_wq, &mgr->work);
ret = 0;
} else {
/* disable MST on the device */
mstb = mgr->mst_primary;
mgr->mst_primary = NULL;
/* this can fail if the device is gone */
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
ret = 0;
memset(mgr->payloads, 0,
mgr->max_payloads * sizeof(mgr->payloads[0]));
memset(mgr->proposed_vcpis, 0,
mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
mgr->payload_mask = 0;
set_bit(0, &mgr->payload_mask);
mgr->vcpi_mask = 0;
mgr->payload_id_table_cleared = false;
}
out_unlock:
mutex_unlock(&mgr->lock);
mutex_unlock(&mgr->payload_lock);
if (mstb)
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
static void
drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
/* The link address will need to be re-sent on resume */
mstb->link_address_sent = false;
list_for_each_entry(port, &mstb->ports, next)
if (port->mstb)
drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
}
/**
* drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
* @mgr: manager to suspend
*
* This function tells the MST device that we can't handle UP messages
* anymore. This should stop it from sending any since we are suspended.
*/
void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->lock);
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UPSTREAM_IS_SRC);
mutex_unlock(&mgr->lock);
flush_work(&mgr->up_req_work);
flush_work(&mgr->work);
flush_work(&mgr->delayed_destroy_work);
mutex_lock(&mgr->lock);
if (mgr->mst_state && mgr->mst_primary)
drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
mutex_unlock(&mgr->lock);
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
/**
* drm_dp_mst_topology_mgr_resume() - resume the MST manager
* @mgr: manager to resume
* @sync: whether or not to perform topology reprobing synchronously
*
* This will fetch DPCD and see if the device is still there,
* if it is, it will rewrite the MSTM control bits, and return.
*
* If the device fails this returns -1, and the driver should do
* a full MST reprobe, in case we were undocked.
*
* During system resume (where it is assumed that the driver will be calling
* drm_atomic_helper_resume()) this function should be called beforehand with
* @sync set to true. In contexts like runtime resume where the driver is not
* expected to be calling drm_atomic_helper_resume(), this function should be
* called with @sync set to false in order to avoid deadlocking.
*
* Returns: -1 if the MST topology was removed while we were suspended, 0
* otherwise.
*/
int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
bool sync)
{
int ret;
u8 guid[16];
mutex_lock(&mgr->lock);
if (!mgr->mst_primary)
goto out_fail;
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
DP_RECEIVER_CAP_SIZE);
if (ret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
goto out_fail;
}
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN |
DP_UP_REQ_EN |
DP_UPSTREAM_IS_SRC);
if (ret < 0) {
DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
goto out_fail;
}
/* Some hubs forget their guids after they resume */
ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
if (ret != 16) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
goto out_fail;
}
ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
if (ret) {
DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n");
goto out_fail;
}
/*
* For the final step of resuming the topology, we need to bring the
* state of our in-memory topology back into sync with reality. So,
* restart the probing process as if we're probing a new hub
*/
queue_work(system_long_wq, &mgr->work);
mutex_unlock(&mgr->lock);
if (sync) {
DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
flush_work(&mgr->work);
}
return 0;
out_fail:
mutex_unlock(&mgr->lock);
return -1;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
static bool
drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
struct drm_dp_mst_branch **mstb)
{
int len;
u8 replyblock[32];
int replylen, curreply;
int ret;
u8 hdrlen;
struct drm_dp_sideband_msg_hdr hdr;
struct drm_dp_sideband_msg_rx *msg =
up ? &mgr->up_req_recv : &mgr->down_rep_recv;
int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
DP_SIDEBAND_MSG_DOWN_REP_BASE;
if (!up)
*mstb = NULL;
len = min(mgr->max_dpcd_transaction_bytes, 16);
ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
if (ret != len) {
DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
return false;
}
ret = drm_dp_decode_sideband_msg_hdr(&hdr, replyblock, len, &hdrlen);
if (ret == false) {
print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
1, replyblock, len, false);
DRM_DEBUG_KMS("ERROR: failed header\n");
return false;
}
if (!up) {
/* Caller is responsible for giving back this reference */
*mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
if (!*mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
hdr.lct);
return false;
}
}
if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
DRM_DEBUG_KMS("sideband msg set header failed %d\n",
replyblock[0]);
return false;
}
replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
if (!ret) {
DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
return false;
}
replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
curreply = len;
while (replylen > 0) {
len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
replyblock, len);
if (ret != len) {
DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
len, ret);
return false;
}
ret = drm_dp_sideband_append_payload(msg, replyblock, len);
if (!ret) {
DRM_DEBUG_KMS("failed to build sideband msg\n");
return false;
}
curreply += len;
replylen -= len;
}
return true;
}
static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb = NULL;
struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
goto out;
/* Multi-packet message transmission, don't clear the reply */
if (!msg->have_eomt)
goto out;
/* find the message */
mutex_lock(&mgr->qlock);
txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
struct drm_dp_sideband_msg_tx, next);
mutex_unlock(&mgr->qlock);
/* Were we actually expecting a response, and from this mstb? */
if (!txmsg || txmsg->dst != mstb) {
struct drm_dp_sideband_msg_hdr *hdr;
hdr = &msg->initial_hdr;
DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
mstb, hdr->seqno, hdr->lct, hdr->rad[0],
msg->msg[0]);
goto out_clear_reply;
}
drm_dp_sideband_parse_reply(msg, &txmsg->reply);
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
txmsg->reply.req_type,
drm_dp_mst_req_type_str(txmsg->reply.req_type),
txmsg->reply.u.nak.reason,
drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
txmsg->reply.u.nak.nak_data);
}
memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
drm_dp_mst_topology_put_mstb(mstb);
mutex_lock(&mgr->qlock);
txmsg->state = DRM_DP_SIDEBAND_TX_RX;
list_del(&txmsg->next);
mutex_unlock(&mgr->qlock);
wake_up_all(&mgr->tx_waitq);
return 0;
out_clear_reply:
memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
out:
if (mstb)
drm_dp_mst_topology_put_mstb(mstb);
return 0;
}
static inline bool
drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_pending_up_req *up_req)
{
struct drm_dp_mst_branch *mstb = NULL;
struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
bool hotplug = false;
if (hdr->broadcast) {
const u8 *guid = NULL;
if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
guid = msg->u.conn_stat.guid;
else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
guid = msg->u.resource_stat.guid;
if (guid)
mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
} else {
mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
}
if (!mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
hdr->lct);
return false;
}
/* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
hotplug = true;
}
drm_dp_mst_topology_put_mstb(mstb);
return hotplug;
}
static void drm_dp_mst_up_req_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr =
container_of(work, struct drm_dp_mst_topology_mgr,
up_req_work);
struct drm_dp_pending_up_req *up_req;
bool send_hotplug = false;
mutex_lock(&mgr->probe_lock);
while (true) {
mutex_lock(&mgr->up_req_lock);
up_req = list_first_entry_or_null(&mgr->up_req_list,
struct drm_dp_pending_up_req,
next);
if (up_req)
list_del(&up_req->next);
mutex_unlock(&mgr->up_req_lock);
if (!up_req)
break;
send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
kfree(up_req);
}
mutex_unlock(&mgr->probe_lock);
if (send_hotplug)
drm_kms_helper_hotplug_event(mgr->dev);
}
static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_pending_up_req *up_req;
if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
goto out;
if (!mgr->up_req_recv.have_eomt)
return 0;
up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
if (!up_req) {
DRM_ERROR("Not enough memory to process MST up req\n");
return -ENOMEM;
}
INIT_LIST_HEAD(&up_req->next);
drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg);
if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
up_req->msg.req_type);
kfree(up_req);
goto out;
}
drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
false);
if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
const struct drm_dp_connection_status_notify *conn_stat =
&up_req->msg.u.conn_stat;
DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
conn_stat->port_number,
conn_stat->legacy_device_plug_status,
conn_stat->displayport_device_plug_status,
conn_stat->message_capability_status,
conn_stat->input_port,
conn_stat->peer_device_type);
} else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
const struct drm_dp_resource_status_notify *res_stat =
&up_req->msg.u.resource_stat;
DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
res_stat->port_number,
res_stat->available_pbn);
}
up_req->hdr = mgr->up_req_recv.initial_hdr;
mutex_lock(&mgr->up_req_lock);
list_add_tail(&up_req->next, &mgr->up_req_list);
mutex_unlock(&mgr->up_req_lock);
queue_work(system_long_wq, &mgr->up_req_work);
out:
memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
}
/**
* drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
* @mgr: manager to notify irq for.
* @esi: 4 bytes from SINK_COUNT_ESI
* @handled: whether the hpd interrupt was consumed or not
*
* This should be called from the driver when it detects a short IRQ,
* along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
* topology manager will process the sideband messages received as a result
* of this.
*/
int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
{
int ret = 0;
int sc;
*handled = false;
sc = esi[0] & 0x3f;
if (sc != mgr->sink_count) {
mgr->sink_count = sc;
*handled = true;
}
if (esi[1] & DP_DOWN_REP_MSG_RDY) {
ret = drm_dp_mst_handle_down_rep(mgr);
*handled = true;
}
if (esi[1] & DP_UP_REQ_MSG_RDY) {
ret |= drm_dp_mst_handle_up_req(mgr);
*handled = true;
}
drm_dp_mst_kick_tx(mgr);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
/**
* drm_dp_mst_detect_port() - get connection status for an MST port
* @connector: DRM connector for this port
* @ctx: The acquisition context to use for grabbing locks
* @mgr: manager for this port
* @port: pointer to a port
*
* This returns the current connection state for a port.
*/
int
drm_dp_mst_detect_port(struct drm_connector *connector,
struct drm_modeset_acquire_ctx *ctx,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
int ret;
/* we need to search for the port in the mgr in case it's gone */
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return connector_status_disconnected;
ret = drm_modeset_lock(&mgr->base.lock, ctx);
if (ret)
goto out;
ret = connector_status_disconnected;
if (!port->ddps)
goto out;
switch (port->pdt) {
case DP_PEER_DEVICE_NONE:
case DP_PEER_DEVICE_MST_BRANCHING:
if (!port->mcs)
ret = connector_status_connected;
break;
case DP_PEER_DEVICE_SST_SINK:
ret = connector_status_connected;
/* for logical ports - cache the EDID */
if (port->port_num >= 8 && !port->cached_edid) {
port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
}
break;
case DP_PEER_DEVICE_DP_LEGACY_CONV:
if (port->ldps)
ret = connector_status_connected;
break;
}
out:
drm_dp_mst_topology_put_port(port);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_detect_port);
/**
* drm_dp_mst_get_edid() - get EDID for an MST port
* @connector: toplevel connector to get EDID for
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This returns an EDID for the port connected to a connector,
* It validates the pointer still exists so the caller doesn't require a
* reference.
*/
struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
struct edid *edid = NULL;
/* we need to search for the port in the mgr in case it's gone */
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return NULL;
if (port->cached_edid)
edid = drm_edid_duplicate(port->cached_edid);
else {
edid = drm_get_edid(connector, &port->aux.ddc);
}
port->has_audio = drm_detect_monitor_audio(edid);
drm_dp_mst_topology_put_port(port);
return edid;
}
EXPORT_SYMBOL(drm_dp_mst_get_edid);
/**
* drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
* @mgr: manager to use
* @pbn: payload bandwidth to convert into slots.
*
* Calculate the number of VCPI slots that will be required for the given PBN
* value. This function is deprecated, and should not be used in atomic
* drivers.
*
* RETURNS:
* The total slots required for this port, or error.
*/
int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
int pbn)
{
int num_slots;
num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
/* max. time slots - one slot for MTP header */
if (num_slots > 63)
return -ENOSPC;
return num_slots;
}
EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi, int pbn, int slots)
{
int ret;
/* max. time slots - one slot for MTP header */
if (slots > 63)
return -ENOSPC;
vcpi->pbn = pbn;
vcpi->aligned_pbn = slots * mgr->pbn_div;
vcpi->num_slots = slots;
ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
if (ret < 0)
return ret;
return 0;
}
/**
* drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
* @state: global atomic state
* @mgr: MST topology manager for the port
* @port: port to find vcpi slots for
* @pbn: bandwidth required for the mode in PBN
* @pbn_div: divider for DSC mode that takes FEC into account
*
* Allocates VCPI slots to @port, replacing any previous VCPI allocations it
* may have had. Any atomic drivers which support MST must call this function
* in their &drm_encoder_helper_funcs.atomic_check() callback to change the
* current VCPI allocation for the new state, but only when
* &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
* to ensure compatibility with userspace applications that still use the
* legacy modesetting UAPI.
*
* Allocations set by this function are not checked against the bandwidth
* restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
*
* Additionally, it is OK to call this function multiple times on the same
* @port as needed. It is not OK however, to call this function and
* drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
*
* See also:
* drm_dp_atomic_release_vcpi_slots()
* drm_dp_mst_atomic_check()
*
* Returns:
* Total slots in the atomic state assigned for this port, or a negative error
* code if the port no longer exists
*/
int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, int pbn,
int pbn_div)
{
struct drm_dp_mst_topology_state *topology_state;
struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
int prev_slots, prev_bw, req_slots;
topology_state = drm_atomic_get_mst_topology_state(state, mgr);
if (IS_ERR(topology_state))
return PTR_ERR(topology_state);
/* Find the current allocation for this port, if any */
list_for_each_entry(pos, &topology_state->vcpis, next) {
if (pos->port == port) {
vcpi = pos;
prev_slots = vcpi->vcpi;
prev_bw = vcpi->pbn;
/*
* This should never happen, unless the driver tries
* releasing and allocating the same VCPI allocation,
* which is an error
*/
if (WARN_ON(!prev_slots)) {
DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
port);
return -EINVAL;
}
break;
}
}
if (!vcpi) {
prev_slots = 0;
prev_bw = 0;
}
if (pbn_div <= 0)
pbn_div = mgr->pbn_div;
req_slots = DIV_ROUND_UP(pbn, pbn_div);
DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
port->connector->base.id, port->connector->name,
port, prev_slots, req_slots);
DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
port->connector->base.id, port->connector->name,
port, prev_bw, pbn);
/* Add the new allocation to the state */
if (!vcpi) {
vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
if (!vcpi)
return -ENOMEM;
drm_dp_mst_get_port_malloc(port);
vcpi->port = port;
list_add(&vcpi->next, &topology_state->vcpis);
}
vcpi->vcpi = req_slots;
vcpi->pbn = pbn;
return req_slots;
}
EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
/**
* drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
* @state: global atomic state
* @mgr: MST topology manager for the port
* @port: The port to release the VCPI slots from
*
* Releases any VCPI slots that have been allocated to a port in the atomic
* state. Any atomic drivers which support MST must call this function in
* their &drm_connector_helper_funcs.atomic_check() callback when the
* connector will no longer have VCPI allocated (e.g. because its CRTC was
* removed) when it had VCPI allocated in the previous atomic state.
*
* It is OK to call this even if @port has been removed from the system.
* Additionally, it is OK to call this function multiple times on the same
* @port as needed. It is not OK however, to call this function and
* drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
* phase.
*
* See also:
* drm_dp_atomic_find_vcpi_slots()
* drm_dp_mst_atomic_check()
*
* Returns:
* 0 if all slots for this port were added back to
* &drm_dp_mst_topology_state.avail_slots or negative error code
*/
int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
struct drm_dp_mst_topology_state *topology_state;
struct drm_dp_vcpi_allocation *pos;
bool found = false;
topology_state = drm_atomic_get_mst_topology_state(state, mgr);
if (IS_ERR(topology_state))
return PTR_ERR(topology_state);
list_for_each_entry(pos, &topology_state->vcpis, next) {
if (pos->port == port) {
found = true;
break;
}
}
if (WARN_ON(!found)) {
DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
port, &topology_state->base);
return -EINVAL;
}
DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
if (pos->vcpi) {
drm_dp_mst_put_port_malloc(port);
pos->vcpi = 0;
pos->pbn = 0;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
/**
* drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
* @mgr: manager for this port
* @port: port to allocate a virtual channel for.
* @pbn: payload bandwidth number to request
* @slots: returned number of slots for this PBN.
*/
bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, int pbn, int slots)
{
int ret;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return false;
if (slots < 0)
return false;
if (port->vcpi.vcpi > 0) {
DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
port->vcpi.vcpi, port->vcpi.pbn, pbn);
if (pbn == port->vcpi.pbn) {
drm_dp_mst_topology_put_port(port);
return true;
}
}
ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
if (ret) {
DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
goto out;
}
DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
pbn, port->vcpi.num_slots);
/* Keep port allocated until its payload has been removed */
drm_dp_mst_get_port_malloc(port);
drm_dp_mst_topology_put_port(port);
return true;
out:
return false;
}
EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
int slots = 0;
port = drm_dp_mst_topology_get_port_validated(mgr, port);
if (!port)
return slots;
slots = port->vcpi.num_slots;
drm_dp_mst_topology_put_port(port);
return slots;
}
EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
/**
* drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This just resets the number of slots for the ports VCPI for later programming.
*/
void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
/*
* A port with VCPI will remain allocated until its VCPI is
* released, no verified ref needed
*/
port->vcpi.num_slots = 0;
}
EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
/**
* drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
* @mgr: manager for this port
* @port: port to deallocate vcpi for
*
* This can be called unconditionally, regardless of whether
* drm_dp_mst_allocate_vcpi() succeeded or not.
*/
void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port)
{
if (!port->vcpi.vcpi)
return;
drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
port->vcpi.num_slots = 0;
port->vcpi.pbn = 0;
port->vcpi.aligned_pbn = 0;
port->vcpi.vcpi = 0;
drm_dp_mst_put_port_malloc(port);
}
EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id, struct drm_dp_payload *payload)
{
u8 payload_alloc[3], status;
int ret;
int retries = 0;
drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
DP_PAYLOAD_TABLE_UPDATED);
payload_alloc[0] = id;
payload_alloc[1] = payload->start_slot;
payload_alloc[2] = payload->num_slots;
ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
if (ret != 3) {
DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
goto fail;
}
retry:
ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
if (ret < 0) {
DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
goto fail;
}
if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
retries++;
if (retries < 20) {
usleep_range(10000, 20000);
goto retry;
}
DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
ret = -EINVAL;
goto fail;
}
ret = 0;
fail:
return ret;
}
static int do_get_act_status(struct drm_dp_aux *aux)
{
int ret;
u8 status;
ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
if (ret < 0)
return ret;
return status;
}
/**
* drm_dp_check_act_status() - Polls for ACT handled status.
* @mgr: manager to use
*
* Tries waiting for the MST hub to finish updating it's payload table by
* polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
* take that long).
*
* Returns:
* 0 if the ACT was handled in time, negative error code on failure.
*/
int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
{
/*
* There doesn't seem to be any recommended retry count or timeout in
* the MST specification. Since some hubs have been observed to take
* over 1 second to update their payload allocations under certain
* conditions, we use a rather large timeout value.
*/
const int timeout_ms = 3000;
int ret, status;
ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
status & DP_PAYLOAD_ACT_HANDLED || status < 0,
200, timeout_ms * USEC_PER_MSEC);
if (ret < 0 && status >= 0) {
DRM_ERROR("Failed to get ACT after %dms, last status: %02x\n",
timeout_ms, status);
return -EINVAL;
} else if (status < 0) {
/*
* Failure here isn't unexpected - the hub may have
* just been unplugged
*/
DRM_DEBUG_KMS("Failed to read payload table status: %d\n",
status);
return status;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_check_act_status);
/**
* drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
* @clock: dot clock for the mode
* @bpp: bpp for the mode.
* @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
*
* This uses the formula in the spec to calculate the PBN value for a mode.
*/
int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
{
/*
* margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
* The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
* common multiplier to render an integer PBN for all link rate/lane
* counts combinations
* calculate
* peak_kbps *= (1006/1000)
* peak_kbps *= (64/54)
* peak_kbps *= 8 convert to bytes
*
* If the bpp is in units of 1/16, further divide by 16. Put this
* factor in the numerator rather than the denominator to avoid
* integer overflow
*/
if (dsc)
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
8 * 54 * 1000 * 1000);
return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
8 * 54 * 1000 * 1000);
}
EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
/* we want to kick the TX after we've ack the up/down IRQs. */
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
{
queue_work(system_long_wq, &mgr->tx_work);
}
static void drm_dp_mst_dump_mstb(struct seq_file *m,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
int tabs = mstb->lct;
char prefix[10];
int i;
for (i = 0; i < tabs; i++)
prefix[i] = '\t';
prefix[i] = '\0';
seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
list_for_each_entry(port, &mstb->ports, next) {
seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
if (port->mstb)
drm_dp_mst_dump_mstb(m, port->mstb);
}
}
#define DP_PAYLOAD_TABLE_SIZE 64
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf)
{
int i;
for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
if (drm_dp_dpcd_read(mgr->aux,
DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
&buf[i], 16) != 16)
return false;
}
return true;
}
static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port, char *name,
int namelen)
{
struct edid *mst_edid;
mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
drm_edid_get_monitor_name(mst_edid, name, namelen);
}
/**
* drm_dp_mst_dump_topology(): dump topology to seq file.
* @m: seq_file to dump output to
* @mgr: manager to dump current topology for.
*
* helper to dump MST topology to a seq file for debugfs.
*/
void drm_dp_mst_dump_topology(struct seq_file *m,
struct drm_dp_mst_topology_mgr *mgr)
{
int i;
struct drm_dp_mst_port *port;
mutex_lock(&mgr->lock);
if (mgr->mst_primary)
drm_dp_mst_dump_mstb(m, mgr->mst_primary);
/* dump VCPIs */
mutex_unlock(&mgr->lock);
mutex_lock(&mgr->payload_lock);
seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
mgr->max_payloads);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i]) {
char name[14];
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
fetch_monitor_name(mgr, port, name, sizeof(name));
seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
port->port_num, port->vcpi.vcpi,
port->vcpi.num_slots,
(*name != 0) ? name : "Unknown");
} else
seq_printf(m, "vcpi %d:unused\n", i);
}
for (i = 0; i < mgr->max_payloads; i++) {
seq_printf(m, "payload %d: %d, %d, %d\n",
i,
mgr->payloads[i].payload_state,
mgr->payloads[i].start_slot,
mgr->payloads[i].num_slots);
}
mutex_unlock(&mgr->payload_lock);
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
u8 buf[DP_PAYLOAD_TABLE_SIZE];
int ret;
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
if (ret) {
seq_printf(m, "dpcd read failed\n");
goto out;
}
seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
if (ret) {
seq_printf(m, "faux/mst read failed\n");
goto out;
}
seq_printf(m, "faux/mst: %*ph\n", 2, buf);
ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
if (ret) {
seq_printf(m, "mst ctrl read failed\n");
goto out;
}
seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
/* dump the standard OUI branch header */
ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
if (ret) {
seq_printf(m, "branch oui read failed\n");
goto out;
}
seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
for (i = 0x3; i < 0x8 && buf[i]; i++)
seq_printf(m, "%c", buf[i]);
seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
if (dump_dp_payload_table(mgr, buf))
seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
}
out:
mutex_unlock(&mgr->lock);
}
EXPORT_SYMBOL(drm_dp_mst_dump_topology);
static void drm_dp_tx_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
mutex_lock(&mgr->qlock);
if (!list_empty(&mgr->tx_msg_downq))
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
static inline void
drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
{
drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
if (port->connector) {
drm_connector_unregister(port->connector);
drm_connector_put(port->connector);
}
drm_dp_mst_put_port_malloc(port);
}
static inline void
drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
struct drm_dp_mst_port *port, *port_tmp;
struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
bool wake_tx = false;
mutex_lock(&mgr->lock);
list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
list_del(&port->next);
drm_dp_mst_topology_put_port(port);
}
mutex_unlock(&mgr->lock);
/* drop any tx slot msg */
mutex_lock(&mstb->mgr->qlock);
list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
if (txmsg->dst != mstb)
continue;
txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
list_del(&txmsg->next);
wake_tx = true;
}
mutex_unlock(&mstb->mgr->qlock);
if (wake_tx)
wake_up_all(&mstb->mgr->tx_waitq);
drm_dp_mst_put_mstb_malloc(mstb);
}
static void drm_dp_delayed_destroy_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr =
container_of(work, struct drm_dp_mst_topology_mgr,
delayed_destroy_work);
bool send_hotplug = false, go_again;
/*
* Not a regular list traverse as we have to drop the destroy
* connector lock before destroying the mstb/port, to avoid AB->BA
* ordering between this lock and the config mutex.
*/
do {
go_again = false;
for (;;) {
struct drm_dp_mst_branch *mstb;
mutex_lock(&mgr->delayed_destroy_lock);
mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
struct drm_dp_mst_branch,
destroy_next);
if (mstb)
list_del(&mstb->destroy_next);
mutex_unlock(&mgr->delayed_destroy_lock);
if (!mstb)
break;
drm_dp_delayed_destroy_mstb(mstb);
go_again = true;
}
for (;;) {
struct drm_dp_mst_port *port;
mutex_lock(&mgr->delayed_destroy_lock);
port = list_first_entry_or_null(&mgr->destroy_port_list,
struct drm_dp_mst_port,
next);
if (port)
list_del(&port->next);
mutex_unlock(&mgr->delayed_destroy_lock);
if (!port)
break;
drm_dp_delayed_destroy_port(port);
send_hotplug = true;
go_again = true;
}
} while (go_again);
if (send_hotplug)
drm_kms_helper_hotplug_event(mgr->dev);
}
static struct drm_private_state *
drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
{
struct drm_dp_mst_topology_state *state, *old_state =
to_dp_mst_topology_state(obj->state);
struct drm_dp_vcpi_allocation *pos, *vcpi;
state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
if (!state)
return NULL;
__drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
INIT_LIST_HEAD(&state->vcpis);
list_for_each_entry(pos, &old_state->vcpis, next) {
/* Prune leftover freed VCPI allocations */
if (!pos->vcpi)
continue;
vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
if (!vcpi)
goto fail;
drm_dp_mst_get_port_malloc(vcpi->port);
list_add(&vcpi->next, &state->vcpis);
}
return &state->base;
fail:
list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
drm_dp_mst_put_port_malloc(pos->port);
kfree(pos);
}
kfree(state);
return NULL;
}
static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
struct drm_private_state *state)
{
struct drm_dp_mst_topology_state *mst_state =
to_dp_mst_topology_state(state);
struct drm_dp_vcpi_allocation *pos, *tmp;
list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
/* We only keep references to ports with non-zero VCPIs */
if (pos->vcpi)
drm_dp_mst_put_port_malloc(pos->port);
kfree(pos);
}
kfree(mst_state);
}
static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
struct drm_dp_mst_branch *branch)
{
while (port->parent) {
if (port->parent == branch)
return true;
if (port->parent->port_parent)
port = port->parent->port_parent;
else
break;
}
return false;
}
static int
drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
struct drm_dp_mst_topology_state *state);
static int
drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_topology_state *state)
{
struct drm_dp_vcpi_allocation *vcpi;
struct drm_dp_mst_port *port;
int pbn_used = 0, ret;
bool found = false;
/* Check that we have at least one port in our state that's downstream
* of this branch, otherwise we can skip this branch
*/
list_for_each_entry(vcpi, &state->vcpis, next) {
if (!vcpi->pbn ||
!drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
continue;
found = true;
break;
}
if (!found)
return 0;
if (mstb->port_parent)
DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
mstb->port_parent->parent, mstb->port_parent,
mstb);
else
DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
mstb);
list_for_each_entry(port, &mstb->ports, next) {
ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
if (ret < 0)
return ret;
pbn_used += ret;
}
return pbn_used;
}
static int
drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
struct drm_dp_mst_topology_state *state)
{
struct drm_dp_vcpi_allocation *vcpi;
int pbn_used = 0;
if (port->pdt == DP_PEER_DEVICE_NONE)
return 0;
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
bool found = false;
list_for_each_entry(vcpi, &state->vcpis, next) {
if (vcpi->port != port)
continue;
if (!vcpi->pbn)
return 0;
found = true;
break;
}
if (!found)
return 0;
/* This should never happen, as it means we tried to
* set a mode before querying the full_pbn
*/
if (WARN_ON(!port->full_pbn))
return -EINVAL;
pbn_used = vcpi->pbn;
} else {
pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
state);
if (pbn_used <= 0)
return pbn_used;
}
if (pbn_used > port->full_pbn) {
DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
port->parent, port, pbn_used,
port->full_pbn);
return -ENOSPC;
}
DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
port->parent, port, pbn_used, port->full_pbn);
return pbn_used;
}
static inline int
drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_topology_state *mst_state)
{
struct drm_dp_vcpi_allocation *vcpi;
int avail_slots = 63, payload_count = 0;
list_for_each_entry(vcpi, &mst_state->vcpis, next) {
/* Releasing VCPI is always OK-even if the port is gone */
if (!vcpi->vcpi) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
vcpi->port);
continue;
}
DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
vcpi->port, vcpi->vcpi);
avail_slots -= vcpi->vcpi;
if (avail_slots < 0) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
vcpi->port, mst_state,
avail_slots + vcpi->vcpi);
return -ENOSPC;
}
if (++payload_count > mgr->max_payloads) {
DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
mgr, mst_state, mgr->max_payloads);
return -EINVAL;
}
}
DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
mgr, mst_state, avail_slots,
63 - avail_slots);
return 0;
}
/**
* drm_dp_mst_add_affected_dsc_crtcs
* @state: Pointer to the new struct drm_dp_mst_topology_state
* @mgr: MST topology manager
*
* Whenever there is a change in mst topology
* DSC configuration would have to be recalculated
* therefore we need to trigger modeset on all affected
* CRTCs in that topology
*
* See also:
* drm_dp_mst_atomic_enable_dsc()
*/
int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_mst_topology_state *mst_state;
struct drm_dp_vcpi_allocation *pos;
struct drm_connector *connector;
struct drm_connector_state *conn_state;
struct drm_crtc *crtc;
struct drm_crtc_state *crtc_state;
mst_state = drm_atomic_get_mst_topology_state(state, mgr);
if (IS_ERR(mst_state))
return -EINVAL;
list_for_each_entry(pos, &mst_state->vcpis, next) {
connector = pos->port->connector;
if (!connector)
return -EINVAL;
conn_state = drm_atomic_get_connector_state(state, connector);
if (IS_ERR(conn_state))
return PTR_ERR(conn_state);
crtc = conn_state->crtc;
if (WARN_ON(!crtc))
return -EINVAL;
if (!drm_dp_mst_dsc_aux_for_port(pos->port))
continue;
crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
if (IS_ERR(crtc_state))
return PTR_ERR(crtc_state);
DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
mgr, crtc);
crtc_state->mode_changed = true;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
/**
* drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
* @state: Pointer to the new drm_atomic_state
* @port: Pointer to the affected MST Port
* @pbn: Newly recalculated bw required for link with DSC enabled
* @pbn_div: Divider to calculate correct number of pbn per slot
* @enable: Boolean flag to enable or disable DSC on the port
*
* This function enables DSC on the given Port
* by recalculating its vcpi from pbn provided
* and sets dsc_enable flag to keep track of which
* ports have DSC enabled
*
*/
int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
struct drm_dp_mst_port *port,
int pbn, int pbn_div,
bool enable)
{
struct drm_dp_mst_topology_state *mst_state;
struct drm_dp_vcpi_allocation *pos;
bool found = false;
int vcpi = 0;
mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
if (IS_ERR(mst_state))
return PTR_ERR(mst_state);
list_for_each_entry(pos, &mst_state->vcpis, next) {
if (pos->port == port) {
found = true;
break;
}
}
if (!found) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
port, mst_state);
return -EINVAL;
}
if (pos->dsc_enabled == enable) {
DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
port, enable, pos->vcpi);
vcpi = pos->vcpi;
}
if (enable) {
vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
port, vcpi);
if (vcpi < 0)
return -EINVAL;
}
pos->dsc_enabled = enable;
return vcpi;
}
EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
/**
* drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
* atomic update is valid
* @state: Pointer to the new &struct drm_dp_mst_topology_state
*
* Checks the given topology state for an atomic update to ensure that it's
* valid. This includes checking whether there's enough bandwidth to support
* the new VCPI allocations in the atomic update.
*
* Any atomic drivers supporting DP MST must make sure to call this after
* checking the rest of their state in their
* &drm_mode_config_funcs.atomic_check() callback.
*
* See also:
* drm_dp_atomic_find_vcpi_slots()
* drm_dp_atomic_release_vcpi_slots()
*
* Returns:
*
* 0 if the new state is valid, negative error code otherwise.
*/
int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
{
struct drm_dp_mst_topology_mgr *mgr;
struct drm_dp_mst_topology_state *mst_state;
int i, ret = 0;
for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
if (!mgr->mst_state)
continue;
ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
if (ret)
break;
mutex_lock(&mgr->lock);
ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
mst_state);
mutex_unlock(&mgr->lock);
if (ret < 0)
break;
else
ret = 0;
}
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_atomic_check);
const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
.atomic_duplicate_state = drm_dp_mst_duplicate_state,
.atomic_destroy_state = drm_dp_mst_destroy_state,
};
EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
/**
* drm_atomic_get_mst_topology_state: get MST topology state
*
* @state: global atomic state
* @mgr: MST topology manager, also the private object in this case
*
* This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
* state vtable so that the private object state returned is that of a MST
* topology object. Also, drm_atomic_get_private_obj_state() expects the caller
* to care of the locking, so warn if don't hold the connection_mutex.
*
* RETURNS:
*
* The MST topology state or error pointer.
*/
struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
struct drm_dp_mst_topology_mgr *mgr)
{
return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
}
EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
/**
* drm_dp_mst_topology_mgr_init - initialise a topology manager
* @mgr: manager struct to initialise
* @dev: device providing this structure - for i2c addition.
* @aux: DP helper aux channel to talk to this device
* @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
* @max_payloads: maximum number of payloads this GPU can source
* @conn_base_id: the connector object ID the MST device is connected to.
*
* Return 0 for success, or negative error code on failure
*/
int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
struct drm_device *dev, struct drm_dp_aux *aux,
int max_dpcd_transaction_bytes,
int max_payloads, int conn_base_id)
{
struct drm_dp_mst_topology_state *mst_state;
mutex_init(&mgr->lock);
mutex_init(&mgr->qlock);
mutex_init(&mgr->payload_lock);
mutex_init(&mgr->delayed_destroy_lock);
mutex_init(&mgr->up_req_lock);
mutex_init(&mgr->probe_lock);
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
mutex_init(&mgr->topology_ref_history_lock);
#endif
INIT_LIST_HEAD(&mgr->tx_msg_downq);
INIT_LIST_HEAD(&mgr->destroy_port_list);
INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
INIT_LIST_HEAD(&mgr->up_req_list);
/*
* delayed_destroy_work will be queued on a dedicated WQ, so that any
* requeuing will be also flushed when deiniting the topology manager.
*/
mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
if (mgr->delayed_destroy_wq == NULL)
return -ENOMEM;
INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
init_waitqueue_head(&mgr->tx_waitq);
mgr->dev = dev;
mgr->aux = aux;
mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
mgr->max_payloads = max_payloads;
mgr->conn_base_id = conn_base_id;
if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
return -EINVAL;
mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
if (!mgr->payloads)
return -ENOMEM;
mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
if (!mgr->proposed_vcpis)
return -ENOMEM;
set_bit(0, &mgr->payload_mask);
mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
if (mst_state == NULL)
return -ENOMEM;
mst_state->mgr = mgr;
INIT_LIST_HEAD(&mst_state->vcpis);
drm_atomic_private_obj_init(dev, &mgr->base,
&mst_state->base,
&drm_dp_mst_topology_state_funcs);
return 0;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
/**
* drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
* @mgr: manager to destroy
*/
void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
{
drm_dp_mst_topology_mgr_set_mst(mgr, false);
flush_work(&mgr->work);
/* The following will also drain any requeued work on the WQ. */
if (mgr->delayed_destroy_wq) {
destroy_workqueue(mgr->delayed_destroy_wq);
mgr->delayed_destroy_wq = NULL;
}
mutex_lock(&mgr->payload_lock);
kfree(mgr->payloads);
mgr->payloads = NULL;
kfree(mgr->proposed_vcpis);
mgr->proposed_vcpis = NULL;
mutex_unlock(&mgr->payload_lock);
mgr->dev = NULL;
mgr->aux = NULL;
drm_atomic_private_obj_fini(&mgr->base);
mgr->funcs = NULL;
mutex_destroy(&mgr->delayed_destroy_lock);
mutex_destroy(&mgr->payload_lock);
mutex_destroy(&mgr->qlock);
mutex_destroy(&mgr->lock);
mutex_destroy(&mgr->up_req_lock);
mutex_destroy(&mgr->probe_lock);
#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
mutex_destroy(&mgr->topology_ref_history_lock);
#endif
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
{
int i;
if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
return false;
for (i = 0; i < num - 1; i++) {
if (msgs[i].flags & I2C_M_RD ||
msgs[i].len > 0xff)
return false;
}
return msgs[num - 1].flags & I2C_M_RD &&
msgs[num - 1].len <= 0xff;
}
/* I2C device */
static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
int num)
{
struct drm_dp_aux *aux = adapter->algo_data;
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
unsigned int i;
struct drm_dp_sideband_msg_req_body msg;
struct drm_dp_sideband_msg_tx *txmsg = NULL;
int ret;
mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
if (!mstb)
return -EREMOTEIO;
if (!remote_i2c_read_ok(msgs, num)) {
DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
ret = -EIO;
goto out;
}
memset(&msg, 0, sizeof(msg));
msg.req_type = DP_REMOTE_I2C_READ;
msg.u.i2c_read.num_transactions = num - 1;
msg.u.i2c_read.port_number = port->port_num;
for (i = 0; i < num - 1; i++) {
msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
}
msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto out;
}
txmsg->dst = mstb;
drm_dp_encode_sideband_req(&msg, txmsg);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
ret = -EREMOTEIO;
goto out;
}
if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
ret = -EIO;
goto out;
}
memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
ret = num;
}
out:
kfree(txmsg);
drm_dp_mst_topology_put_mstb(mstb);
return ret;
}
static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR;
}
static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
.functionality = drm_dp_mst_i2c_functionality,
.master_xfer = drm_dp_mst_i2c_xfer,
};
/**
* drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
* @port: The port to add the I2C bus on
*
* Returns 0 on success or a negative error code on failure.
*/
static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
{
struct drm_dp_aux *aux = &port->aux;
struct device *parent_dev = port->mgr->dev->dev;
aux->ddc.algo = &drm_dp_mst_i2c_algo;
aux->ddc.algo_data = aux;
aux->ddc.retries = 3;
aux->ddc.class = I2C_CLASS_DDC;
aux->ddc.owner = THIS_MODULE;
/* FIXME: set the kdev of the port's connector as parent */
aux->ddc.dev.parent = parent_dev;
aux->ddc.dev.of_node = parent_dev->of_node;
strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
sizeof(aux->ddc.name));
return i2c_add_adapter(&aux->ddc);
}
/**
* drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
* @port: The port to remove the I2C bus from
*/
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
{
i2c_del_adapter(&port->aux.ddc);
}
/**
* drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
* @port: The port to check
*
* A single physical MST hub object can be represented in the topology
* by multiple branches, with virtual ports between those branches.
*
* As of DP1.4, An MST hub with internal (virtual) ports must expose
* certain DPCD registers over those ports. See sections 2.6.1.1.1
* and 2.6.1.1.2 of Display Port specification v1.4 for details.
*
* May acquire mgr->lock
*
* Returns:
* true if the port is a virtual DP peer device, false otherwise
*/
static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
{
struct drm_dp_mst_port *downstream_port;
if (!port || port->dpcd_rev < DP_DPCD_REV_14)
return false;
/* Virtual DP Sink (Internal Display Panel) */
if (port->port_num >= 8)
return true;
/* DP-to-HDMI Protocol Converter */
if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
!port->mcs &&
port->ldps)
return true;
/* DP-to-DP */
mutex_lock(&port->mgr->lock);
if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
port->mstb &&
port->mstb->num_ports == 2) {
list_for_each_entry(downstream_port, &port->mstb->ports, next) {
if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
!downstream_port->input) {
mutex_unlock(&port->mgr->lock);
return true;
}
}
}
mutex_unlock(&port->mgr->lock);
return false;
}
/**
* drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
* @port: The port to check. A leaf of the MST tree with an attached display.
*
* Depending on the situation, DSC may be enabled via the endpoint aux,
* the immediately upstream aux, or the connector's physical aux.
*
* This is both the correct aux to read DSC_CAPABILITY and the
* correct aux to write DSC_ENABLED.
*
* This operation can be expensive (up to four aux reads), so
* the caller should cache the return.
*
* Returns:
* NULL if DSC cannot be enabled on this port, otherwise the aux device
*/
struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
{
struct drm_dp_mst_port *immediate_upstream_port;
struct drm_dp_mst_port *fec_port;
struct drm_dp_desc desc = {};
u8 endpoint_fec;
u8 endpoint_dsc;
if (!port)
return NULL;
if (port->parent->port_parent)
immediate_upstream_port = port->parent->port_parent;
else
immediate_upstream_port = NULL;
fec_port = immediate_upstream_port;
while (fec_port) {
/*
* Each physical link (i.e. not a virtual port) between the
* output and the primary device must support FEC
*/
if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
!fec_port->fec_capable)
return NULL;
fec_port = fec_port->parent->port_parent;
}
/* DP-to-DP peer device */
if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
u8 upstream_dsc;
if (drm_dp_dpcd_read(&port->aux,
DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
return NULL;
if (drm_dp_dpcd_read(&port->aux,
DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
return NULL;
if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
return NULL;
/* Enpoint decompression with DP-to-DP peer device */
if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
(endpoint_fec & DP_FEC_CAPABLE) &&
(upstream_dsc & 0x2) /* DSC passthrough */)
return &port->aux;
/* Virtual DPCD decompression with DP-to-DP peer device */
return &immediate_upstream_port->aux;
}
/* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
if (drm_dp_mst_is_virtual_dpcd(port))
return &port->aux;
/*
* Synaptics quirk
* Applies to ports for which:
* - Physical aux has Synaptics OUI
* - DPv1.4 or higher
* - Port is on primary branch device
* - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
*/
if (drm_dp_read_desc(port->mgr->aux, &desc, true))
return NULL;
if (drm_dp_has_quirk(&desc, 0,
DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
port->parent == port->mgr->mst_primary) {
u8 downstreamport;
if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
&downstreamport, 1) < 0)
return NULL;
if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
!= DP_DWN_STRM_PORT_TYPE_ANALOG))
return port->mgr->aux;
}
/*
* The check below verifies if the MST sink
* connected to the GPU is capable of DSC -
* therefore the endpoint needs to be
* both DSC and FEC capable.
*/
if (drm_dp_dpcd_read(&port->aux,
DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
return NULL;
if (drm_dp_dpcd_read(&port->aux,
DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
return NULL;
if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
(endpoint_fec & DP_FEC_CAPABLE))
return &port->aux;
return NULL;
}
EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
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