linux/drivers/rpmsg/qcom_smd.c
Uwe Kleine-König 38be89514b rpmsg: qcom_smd: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

qcom_smd_remove() always returned zero, though that isn't completely
trivial to see. So explain that in a comment and convert to
.remove_new().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230321154039.355098-4-u.kleine-koenig@pengutronix.de
2023-04-05 20:58:32 -07:00

1621 lines
41 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2015, Sony Mobile Communications AB.
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mailbox_client.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/sched.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem.h>
#include <linux/wait.h>
#include <linux/rpmsg.h>
#include <linux/rpmsg/qcom_smd.h>
#include "rpmsg_internal.h"
/*
* The Qualcomm Shared Memory communication solution provides point-to-point
* channels for clients to send and receive streaming or packet based data.
*
* Each channel consists of a control item (channel info) and a ring buffer
* pair. The channel info carry information related to channel state, flow
* control and the offsets within the ring buffer.
*
* All allocated channels are listed in an allocation table, identifying the
* pair of items by name, type and remote processor.
*
* Upon creating a new channel the remote processor allocates channel info and
* ring buffer items from the smem heap and populate the allocation table. An
* interrupt is sent to the other end of the channel and a scan for new
* channels should be done. A channel never goes away, it will only change
* state.
*
* The remote processor signals it intent for bring up the communication
* channel by setting the state of its end of the channel to "opening" and
* sends out an interrupt. We detect this change and register a smd device to
* consume the channel. Upon finding a consumer we finish the handshake and the
* channel is up.
*
* Upon closing a channel, the remote processor will update the state of its
* end of the channel and signal us, we will then unregister any attached
* device and close our end of the channel.
*
* Devices attached to a channel can use the qcom_smd_send function to push
* data to the channel, this is done by copying the data into the tx ring
* buffer, updating the pointers in the channel info and signaling the remote
* processor.
*
* The remote processor does the equivalent when it transfer data and upon
* receiving the interrupt we check the channel info for new data and delivers
* this to the attached device. If the device is not ready to receive the data
* we leave it in the ring buffer for now.
*/
struct smd_channel_info;
struct smd_channel_info_pair;
struct smd_channel_info_word;
struct smd_channel_info_word_pair;
static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops;
#define SMD_ALLOC_TBL_COUNT 2
#define SMD_ALLOC_TBL_SIZE 64
/*
* This lists the various smem heap items relevant for the allocation table and
* smd channel entries.
*/
static const struct {
unsigned alloc_tbl_id;
unsigned info_base_id;
unsigned fifo_base_id;
} smem_items[SMD_ALLOC_TBL_COUNT] = {
{
.alloc_tbl_id = 13,
.info_base_id = 14,
.fifo_base_id = 338
},
{
.alloc_tbl_id = 266,
.info_base_id = 138,
.fifo_base_id = 202,
},
};
/**
* struct qcom_smd_edge - representing a remote processor
* @dev: device associated with this edge
* @name: name of this edge
* @of_node: of_node handle for information related to this edge
* @edge_id: identifier of this edge
* @remote_pid: identifier of remote processor
* @irq: interrupt for signals on this edge
* @ipc_regmap: regmap handle holding the outgoing ipc register
* @ipc_offset: offset within @ipc_regmap of the register for ipc
* @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
* @mbox_client: mailbox client handle
* @mbox_chan: apcs ipc mailbox channel handle
* @channels: list of all channels detected on this edge
* @channels_lock: guard for modifications of @channels
* @allocated: array of bitmaps representing already allocated channels
* @smem_available: last available amount of smem triggering a channel scan
* @new_channel_event: wait queue for new channel events
* @scan_work: work item for discovering new channels
* @state_work: work item for edge state changes
*/
struct qcom_smd_edge {
struct device dev;
const char *name;
struct device_node *of_node;
unsigned edge_id;
unsigned remote_pid;
int irq;
struct regmap *ipc_regmap;
int ipc_offset;
int ipc_bit;
struct mbox_client mbox_client;
struct mbox_chan *mbox_chan;
struct list_head channels;
spinlock_t channels_lock;
DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
unsigned smem_available;
wait_queue_head_t new_channel_event;
struct work_struct scan_work;
struct work_struct state_work;
};
/*
* SMD channel states.
*/
enum smd_channel_state {
SMD_CHANNEL_CLOSED,
SMD_CHANNEL_OPENING,
SMD_CHANNEL_OPENED,
SMD_CHANNEL_FLUSHING,
SMD_CHANNEL_CLOSING,
SMD_CHANNEL_RESET,
SMD_CHANNEL_RESET_OPENING
};
struct qcom_smd_device {
struct rpmsg_device rpdev;
struct qcom_smd_edge *edge;
};
struct qcom_smd_endpoint {
struct rpmsg_endpoint ept;
struct qcom_smd_channel *qsch;
};
#define to_smd_device(r) container_of(r, struct qcom_smd_device, rpdev)
#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev)
#define to_smd_endpoint(e) container_of(e, struct qcom_smd_endpoint, ept)
/**
* struct qcom_smd_channel - smd channel struct
* @edge: qcom_smd_edge this channel is living on
* @qsept: reference to a associated smd endpoint
* @registered: flag to indicate if the channel is registered
* @name: name of the channel
* @state: local state of the channel
* @remote_state: remote state of the channel
* @state_change_event: state change event
* @info: byte aligned outgoing/incoming channel info
* @info_word: word aligned outgoing/incoming channel info
* @tx_lock: lock to make writes to the channel mutually exclusive
* @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
* @tx_fifo: pointer to the outgoing ring buffer
* @rx_fifo: pointer to the incoming ring buffer
* @fifo_size: size of each ring buffer
* @bounce_buffer: bounce buffer for reading wrapped packets
* @cb: callback function registered for this channel
* @recv_lock: guard for rx info modifications and cb pointer
* @pkt_size: size of the currently handled packet
* @drvdata: driver private data
* @list: lite entry for @channels in qcom_smd_edge
*/
struct qcom_smd_channel {
struct qcom_smd_edge *edge;
struct qcom_smd_endpoint *qsept;
bool registered;
char *name;
enum smd_channel_state state;
enum smd_channel_state remote_state;
wait_queue_head_t state_change_event;
struct smd_channel_info_pair *info;
struct smd_channel_info_word_pair *info_word;
spinlock_t tx_lock;
wait_queue_head_t fblockread_event;
void *tx_fifo;
void *rx_fifo;
int fifo_size;
void *bounce_buffer;
spinlock_t recv_lock;
int pkt_size;
void *drvdata;
struct list_head list;
};
/*
* Format of the smd_info smem items, for byte aligned channels.
*/
struct smd_channel_info {
__le32 state;
u8 fDSR;
u8 fCTS;
u8 fCD;
u8 fRI;
u8 fHEAD;
u8 fTAIL;
u8 fSTATE;
u8 fBLOCKREADINTR;
__le32 tail;
__le32 head;
};
struct smd_channel_info_pair {
struct smd_channel_info tx;
struct smd_channel_info rx;
};
/*
* Format of the smd_info smem items, for word aligned channels.
*/
struct smd_channel_info_word {
__le32 state;
__le32 fDSR;
__le32 fCTS;
__le32 fCD;
__le32 fRI;
__le32 fHEAD;
__le32 fTAIL;
__le32 fSTATE;
__le32 fBLOCKREADINTR;
__le32 tail;
__le32 head;
};
struct smd_channel_info_word_pair {
struct smd_channel_info_word tx;
struct smd_channel_info_word rx;
};
#define GET_RX_CHANNEL_FLAG(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
channel->info_word ? \
le32_to_cpu(channel->info_word->rx.param) : \
channel->info->rx.param; \
})
#define GET_RX_CHANNEL_INFO(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
le32_to_cpu(channel->info_word ? \
channel->info_word->rx.param : \
channel->info->rx.param); \
})
#define SET_RX_CHANNEL_FLAG(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
if (channel->info_word) \
channel->info_word->rx.param = cpu_to_le32(value); \
else \
channel->info->rx.param = value; \
})
#define SET_RX_CHANNEL_INFO(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
if (channel->info_word) \
channel->info_word->rx.param = cpu_to_le32(value); \
else \
channel->info->rx.param = cpu_to_le32(value); \
})
#define GET_TX_CHANNEL_FLAG(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
channel->info_word ? \
le32_to_cpu(channel->info_word->tx.param) : \
channel->info->tx.param; \
})
#define GET_TX_CHANNEL_INFO(channel, param) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
le32_to_cpu(channel->info_word ? \
channel->info_word->tx.param : \
channel->info->tx.param); \
})
#define SET_TX_CHANNEL_FLAG(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
if (channel->info_word) \
channel->info_word->tx.param = cpu_to_le32(value); \
else \
channel->info->tx.param = value; \
})
#define SET_TX_CHANNEL_INFO(channel, param, value) \
({ \
BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
if (channel->info_word) \
channel->info_word->tx.param = cpu_to_le32(value); \
else \
channel->info->tx.param = cpu_to_le32(value); \
})
/**
* struct qcom_smd_alloc_entry - channel allocation entry
* @name: channel name
* @cid: channel index
* @flags: channel flags and edge id
* @ref_count: reference count of the channel
*/
struct qcom_smd_alloc_entry {
u8 name[20];
__le32 cid;
__le32 flags;
__le32 ref_count;
} __packed;
#define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
#define SMD_CHANNEL_FLAGS_STREAM BIT(8)
#define SMD_CHANNEL_FLAGS_PACKET BIT(9)
/*
* Each smd packet contains a 20 byte header, with the first 4 being the length
* of the packet.
*/
#define SMD_PACKET_HEADER_LEN 20
/*
* Signal the remote processor associated with 'channel'.
*/
static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
{
struct qcom_smd_edge *edge = channel->edge;
if (edge->mbox_chan) {
/*
* We can ignore a failing mbox_send_message() as the only
* possible cause is that the FIFO in the framework is full of
* other writes to the same bit.
*/
mbox_send_message(edge->mbox_chan, NULL);
mbox_client_txdone(edge->mbox_chan, 0);
} else {
regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
}
}
/*
* Initialize the tx channel info
*/
static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
{
SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
SET_TX_CHANNEL_FLAG(channel, fCD, 0);
SET_TX_CHANNEL_FLAG(channel, fRI, 0);
SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
SET_TX_CHANNEL_INFO(channel, head, 0);
SET_RX_CHANNEL_INFO(channel, tail, 0);
qcom_smd_signal_channel(channel);
channel->state = SMD_CHANNEL_CLOSED;
channel->pkt_size = 0;
}
/*
* Set the callback for a channel, with appropriate locking
*/
static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
rpmsg_rx_cb_t cb)
{
struct rpmsg_endpoint *ept = &channel->qsept->ept;
unsigned long flags;
spin_lock_irqsave(&channel->recv_lock, flags);
ept->cb = cb;
spin_unlock_irqrestore(&channel->recv_lock, flags);
};
/*
* Calculate the amount of data available in the rx fifo
*/
static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
{
unsigned head;
unsigned tail;
head = GET_RX_CHANNEL_INFO(channel, head);
tail = GET_RX_CHANNEL_INFO(channel, tail);
return (head - tail) & (channel->fifo_size - 1);
}
/*
* Set tx channel state and inform the remote processor
*/
static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
int state)
{
struct qcom_smd_edge *edge = channel->edge;
bool is_open = state == SMD_CHANNEL_OPENED;
if (channel->state == state)
return;
dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state);
SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
SET_TX_CHANNEL_INFO(channel, state, state);
SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
channel->state = state;
qcom_smd_signal_channel(channel);
}
/*
* Copy count bytes of data using 32bit accesses, if that's required.
*/
static void smd_copy_to_fifo(void __iomem *dst,
const void *src,
size_t count,
bool word_aligned)
{
if (word_aligned) {
__iowrite32_copy(dst, src, count / sizeof(u32));
} else {
memcpy_toio(dst, src, count);
}
}
/*
* Copy count bytes of data using 32bit accesses, if that is required.
*/
static void smd_copy_from_fifo(void *dst,
const void __iomem *src,
size_t count,
bool word_aligned)
{
if (word_aligned) {
__ioread32_copy(dst, src, count / sizeof(u32));
} else {
memcpy_fromio(dst, src, count);
}
}
/*
* Read count bytes of data from the rx fifo into buf, but don't advance the
* tail.
*/
static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
void *buf, size_t count)
{
bool word_aligned;
unsigned tail;
size_t len;
word_aligned = channel->info_word;
tail = GET_RX_CHANNEL_INFO(channel, tail);
len = min_t(size_t, count, channel->fifo_size - tail);
if (len) {
smd_copy_from_fifo(buf,
channel->rx_fifo + tail,
len,
word_aligned);
}
if (len != count) {
smd_copy_from_fifo(buf + len,
channel->rx_fifo,
count - len,
word_aligned);
}
return count;
}
/*
* Advance the rx tail by count bytes.
*/
static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
size_t count)
{
unsigned tail;
tail = GET_RX_CHANNEL_INFO(channel, tail);
tail += count;
tail &= (channel->fifo_size - 1);
SET_RX_CHANNEL_INFO(channel, tail, tail);
}
/*
* Read out a single packet from the rx fifo and deliver it to the device
*/
static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
{
struct rpmsg_endpoint *ept = &channel->qsept->ept;
unsigned tail;
size_t len;
void *ptr;
int ret;
tail = GET_RX_CHANNEL_INFO(channel, tail);
/* Use bounce buffer if the data wraps */
if (tail + channel->pkt_size >= channel->fifo_size) {
ptr = channel->bounce_buffer;
len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
} else {
ptr = channel->rx_fifo + tail;
len = channel->pkt_size;
}
ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY);
if (ret < 0)
return ret;
/* Only forward the tail if the client consumed the data */
qcom_smd_channel_advance(channel, len);
channel->pkt_size = 0;
return 0;
}
/*
* Per channel interrupt handling
*/
static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
{
bool need_state_scan = false;
int remote_state;
__le32 pktlen;
int avail;
int ret;
/* Handle state changes */
remote_state = GET_RX_CHANNEL_INFO(channel, state);
if (remote_state != channel->remote_state) {
channel->remote_state = remote_state;
need_state_scan = true;
wake_up_interruptible_all(&channel->state_change_event);
}
/* Indicate that we have seen any state change */
SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
/* Signal waiting qcom_smd_send() about the interrupt */
if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
wake_up_interruptible_all(&channel->fblockread_event);
/* Don't consume any data until we've opened the channel */
if (channel->state != SMD_CHANNEL_OPENED)
goto out;
/* Indicate that we've seen the new data */
SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
/* Consume data */
for (;;) {
avail = qcom_smd_channel_get_rx_avail(channel);
if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
channel->pkt_size = le32_to_cpu(pktlen);
} else if (channel->pkt_size && avail >= channel->pkt_size) {
ret = qcom_smd_channel_recv_single(channel);
if (ret)
break;
} else {
break;
}
}
/* Indicate that we have seen and updated tail */
SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
/* Signal the remote that we've consumed the data (if requested) */
if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
/* Ensure ordering of channel info updates */
wmb();
qcom_smd_signal_channel(channel);
}
out:
return need_state_scan;
}
/*
* The edge interrupts are triggered by the remote processor on state changes,
* channel info updates or when new channels are created.
*/
static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
{
struct qcom_smd_edge *edge = data;
struct qcom_smd_channel *channel;
unsigned available;
bool kick_scanner = false;
bool kick_state = false;
/*
* Handle state changes or data on each of the channels on this edge
*/
spin_lock(&edge->channels_lock);
list_for_each_entry(channel, &edge->channels, list) {
spin_lock(&channel->recv_lock);
kick_state |= qcom_smd_channel_intr(channel);
spin_unlock(&channel->recv_lock);
}
spin_unlock(&edge->channels_lock);
/*
* Creating a new channel requires allocating an smem entry, so we only
* have to scan if the amount of available space in smem have changed
* since last scan.
*/
available = qcom_smem_get_free_space(edge->remote_pid);
if (available != edge->smem_available) {
edge->smem_available = available;
kick_scanner = true;
}
if (kick_scanner)
schedule_work(&edge->scan_work);
if (kick_state)
schedule_work(&edge->state_work);
return IRQ_HANDLED;
}
/*
* Calculate how much space is available in the tx fifo.
*/
static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
{
unsigned head;
unsigned tail;
unsigned mask = channel->fifo_size - 1;
head = GET_TX_CHANNEL_INFO(channel, head);
tail = GET_TX_CHANNEL_INFO(channel, tail);
return mask - ((head - tail) & mask);
}
/*
* Write count bytes of data into channel, possibly wrapping in the ring buffer
*/
static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
const void *data,
size_t count)
{
bool word_aligned;
unsigned head;
size_t len;
word_aligned = channel->info_word;
head = GET_TX_CHANNEL_INFO(channel, head);
len = min_t(size_t, count, channel->fifo_size - head);
if (len) {
smd_copy_to_fifo(channel->tx_fifo + head,
data,
len,
word_aligned);
}
if (len != count) {
smd_copy_to_fifo(channel->tx_fifo,
data + len,
count - len,
word_aligned);
}
head += count;
head &= (channel->fifo_size - 1);
SET_TX_CHANNEL_INFO(channel, head, head);
return count;
}
/**
* __qcom_smd_send - write data to smd channel
* @channel: channel handle
* @data: buffer of data to write
* @len: number of bytes to write
* @wait: flag to indicate if write can wait
*
* This is a blocking write of len bytes into the channel's tx ring buffer and
* signal the remote end. It will sleep until there is enough space available
* in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
* polling.
*/
static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
int len, bool wait)
{
__le32 hdr[5] = { cpu_to_le32(len), };
int tlen = sizeof(hdr) + len;
unsigned long flags;
int ret;
/* Word aligned channels only accept word size aligned data */
if (channel->info_word && len % 4)
return -EINVAL;
/* Reject packets that are too big */
if (tlen >= channel->fifo_size)
return -EINVAL;
/* Highlight the fact that if we enter the loop below we might sleep */
if (wait)
might_sleep();
spin_lock_irqsave(&channel->tx_lock, flags);
while (qcom_smd_get_tx_avail(channel) < tlen &&
channel->state == SMD_CHANNEL_OPENED) {
if (!wait) {
ret = -EAGAIN;
goto out_unlock;
}
SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
/* Wait without holding the tx_lock */
spin_unlock_irqrestore(&channel->tx_lock, flags);
ret = wait_event_interruptible(channel->fblockread_event,
qcom_smd_get_tx_avail(channel) >= tlen ||
channel->state != SMD_CHANNEL_OPENED);
if (ret)
return ret;
spin_lock_irqsave(&channel->tx_lock, flags);
SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
}
/* Fail if the channel was closed */
if (channel->state != SMD_CHANNEL_OPENED) {
ret = -EPIPE;
goto out_unlock;
}
SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
qcom_smd_write_fifo(channel, data, len);
SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
/* Ensure ordering of channel info updates */
wmb();
qcom_smd_signal_channel(channel);
out_unlock:
spin_unlock_irqrestore(&channel->tx_lock, flags);
return ret;
}
/*
* Helper for opening a channel
*/
static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
rpmsg_rx_cb_t cb)
{
struct qcom_smd_edge *edge = channel->edge;
size_t bb_size;
int ret;
/*
* Packets are maximum 4k, but reduce if the fifo is smaller
*/
bb_size = min(channel->fifo_size, SZ_4K);
channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
if (!channel->bounce_buffer)
return -ENOMEM;
qcom_smd_channel_set_callback(channel, cb);
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
/* Wait for remote to enter opening or opened */
ret = wait_event_interruptible_timeout(channel->state_change_event,
channel->remote_state == SMD_CHANNEL_OPENING ||
channel->remote_state == SMD_CHANNEL_OPENED,
HZ);
if (!ret) {
dev_err(&edge->dev, "remote side did not enter opening state\n");
goto out_close_timeout;
}
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
/* Wait for remote to enter opened */
ret = wait_event_interruptible_timeout(channel->state_change_event,
channel->remote_state == SMD_CHANNEL_OPENED,
HZ);
if (!ret) {
dev_err(&edge->dev, "remote side did not enter open state\n");
goto out_close_timeout;
}
return 0;
out_close_timeout:
qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
return -ETIMEDOUT;
}
/*
* Helper for closing and resetting a channel
*/
static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
{
qcom_smd_channel_set_callback(channel, NULL);
kfree(channel->bounce_buffer);
channel->bounce_buffer = NULL;
qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
qcom_smd_channel_reset(channel);
}
static struct qcom_smd_channel *
qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
{
struct qcom_smd_channel *channel;
struct qcom_smd_channel *ret = NULL;
unsigned long flags;
spin_lock_irqsave(&edge->channels_lock, flags);
list_for_each_entry(channel, &edge->channels, list) {
if (!strcmp(channel->name, name)) {
ret = channel;
break;
}
}
spin_unlock_irqrestore(&edge->channels_lock, flags);
return ret;
}
static void __ept_release(struct kref *kref)
{
struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
refcount);
kfree(to_smd_endpoint(ept));
}
static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev,
rpmsg_rx_cb_t cb, void *priv,
struct rpmsg_channel_info chinfo)
{
struct qcom_smd_endpoint *qsept;
struct qcom_smd_channel *channel;
struct qcom_smd_device *qsdev = to_smd_device(rpdev);
struct qcom_smd_edge *edge = qsdev->edge;
struct rpmsg_endpoint *ept;
const char *name = chinfo.name;
int ret;
/* Wait up to HZ for the channel to appear */
ret = wait_event_interruptible_timeout(edge->new_channel_event,
(channel = qcom_smd_find_channel(edge, name)) != NULL,
HZ);
if (!ret)
return NULL;
if (channel->state != SMD_CHANNEL_CLOSED) {
dev_err(&rpdev->dev, "channel %s is busy\n", channel->name);
return NULL;
}
qsept = kzalloc(sizeof(*qsept), GFP_KERNEL);
if (!qsept)
return NULL;
ept = &qsept->ept;
kref_init(&ept->refcount);
ept->rpdev = rpdev;
ept->cb = cb;
ept->priv = priv;
ept->ops = &qcom_smd_endpoint_ops;
channel->qsept = qsept;
qsept->qsch = channel;
ret = qcom_smd_channel_open(channel, cb);
if (ret)
goto free_ept;
return ept;
free_ept:
channel->qsept = NULL;
kref_put(&ept->refcount, __ept_release);
return NULL;
}
static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
struct qcom_smd_channel *ch = qsept->qsch;
qcom_smd_channel_close(ch);
ch->qsept = NULL;
kref_put(&ept->refcount, __ept_release);
}
static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
return __qcom_smd_send(qsept->qsch, data, len, true);
}
static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
return __qcom_smd_send(qsept->qsch, data, len, false);
}
static int qcom_smd_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
return __qcom_smd_send(qsept->qsch, data, len, true);
}
static int qcom_smd_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
return __qcom_smd_send(qsept->qsch, data, len, false);
}
static __poll_t qcom_smd_poll(struct rpmsg_endpoint *ept,
struct file *filp, poll_table *wait)
{
struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
struct qcom_smd_channel *channel = qsept->qsch;
__poll_t mask = 0;
poll_wait(filp, &channel->fblockread_event, wait);
if (qcom_smd_get_tx_avail(channel) > 20)
mask |= EPOLLOUT | EPOLLWRNORM;
return mask;
}
/*
* Finds the device_node for the smd child interested in this channel.
*/
static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
const char *channel)
{
struct device_node *child;
const char *name;
const char *key;
int ret;
for_each_available_child_of_node(edge_node, child) {
key = "qcom,smd-channels";
ret = of_property_read_string(child, key, &name);
if (ret)
continue;
if (strcmp(name, channel) == 0)
return child;
}
return NULL;
}
static int qcom_smd_announce_create(struct rpmsg_device *rpdev)
{
struct qcom_smd_endpoint *qept = to_smd_endpoint(rpdev->ept);
struct qcom_smd_channel *channel = qept->qsch;
unsigned long flags;
bool kick_state;
spin_lock_irqsave(&channel->recv_lock, flags);
kick_state = qcom_smd_channel_intr(channel);
spin_unlock_irqrestore(&channel->recv_lock, flags);
if (kick_state)
schedule_work(&channel->edge->state_work);
return 0;
}
static const struct rpmsg_device_ops qcom_smd_device_ops = {
.create_ept = qcom_smd_create_ept,
.announce_create = qcom_smd_announce_create,
};
static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
.destroy_ept = qcom_smd_destroy_ept,
.send = qcom_smd_send,
.sendto = qcom_smd_sendto,
.trysend = qcom_smd_trysend,
.trysendto = qcom_smd_trysendto,
.poll = qcom_smd_poll,
};
static void qcom_smd_release_device(struct device *dev)
{
struct rpmsg_device *rpdev = to_rpmsg_device(dev);
struct qcom_smd_device *qsdev = to_smd_device(rpdev);
kfree(qsdev);
}
/*
* Create a smd client device for channel that is being opened.
*/
static int qcom_smd_create_device(struct qcom_smd_channel *channel)
{
struct qcom_smd_device *qsdev;
struct rpmsg_device *rpdev;
struct qcom_smd_edge *edge = channel->edge;
dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
if (!qsdev)
return -ENOMEM;
/* Link qsdev to our SMD edge */
qsdev->edge = edge;
/* Assign callbacks for rpmsg_device */
qsdev->rpdev.ops = &qcom_smd_device_ops;
/* Assign public information to the rpmsg_device */
rpdev = &qsdev->rpdev;
strscpy_pad(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
rpdev->src = RPMSG_ADDR_ANY;
rpdev->dst = RPMSG_ADDR_ANY;
rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
rpdev->dev.parent = &edge->dev;
rpdev->dev.release = qcom_smd_release_device;
return rpmsg_register_device(rpdev);
}
static int qcom_smd_create_chrdev(struct qcom_smd_edge *edge)
{
struct qcom_smd_device *qsdev;
qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
if (!qsdev)
return -ENOMEM;
qsdev->edge = edge;
qsdev->rpdev.ops = &qcom_smd_device_ops;
qsdev->rpdev.dev.parent = &edge->dev;
qsdev->rpdev.dev.release = qcom_smd_release_device;
return rpmsg_ctrldev_register_device(&qsdev->rpdev);
}
/*
* Allocate the qcom_smd_channel object for a newly found smd channel,
* retrieving and validating the smem items involved.
*/
static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
unsigned smem_info_item,
unsigned smem_fifo_item,
char *name)
{
struct qcom_smd_channel *channel;
size_t fifo_size;
size_t info_size;
void *fifo_base;
void *info;
int ret;
channel = kzalloc(sizeof(*channel), GFP_KERNEL);
if (!channel)
return ERR_PTR(-ENOMEM);
channel->edge = edge;
channel->name = kstrdup(name, GFP_KERNEL);
if (!channel->name) {
ret = -ENOMEM;
goto free_channel;
}
spin_lock_init(&channel->tx_lock);
spin_lock_init(&channel->recv_lock);
init_waitqueue_head(&channel->fblockread_event);
init_waitqueue_head(&channel->state_change_event);
info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
if (IS_ERR(info)) {
ret = PTR_ERR(info);
goto free_name_and_channel;
}
/*
* Use the size of the item to figure out which channel info struct to
* use.
*/
if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
channel->info_word = info;
} else if (info_size == 2 * sizeof(struct smd_channel_info)) {
channel->info = info;
} else {
dev_err(&edge->dev,
"channel info of size %zu not supported\n", info_size);
ret = -EINVAL;
goto free_name_and_channel;
}
fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
if (IS_ERR(fifo_base)) {
ret = PTR_ERR(fifo_base);
goto free_name_and_channel;
}
/* The channel consist of a rx and tx fifo of equal size */
fifo_size /= 2;
dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
name, info_size, fifo_size);
channel->tx_fifo = fifo_base;
channel->rx_fifo = fifo_base + fifo_size;
channel->fifo_size = fifo_size;
qcom_smd_channel_reset(channel);
return channel;
free_name_and_channel:
kfree(channel->name);
free_channel:
kfree(channel);
return ERR_PTR(ret);
}
/*
* Scans the allocation table for any newly allocated channels, calls
* qcom_smd_create_channel() to create representations of these and add
* them to the edge's list of channels.
*/
static void qcom_channel_scan_worker(struct work_struct *work)
{
struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
struct qcom_smd_alloc_entry *alloc_tbl;
struct qcom_smd_alloc_entry *entry;
struct qcom_smd_channel *channel;
unsigned long flags;
unsigned fifo_id;
unsigned info_id;
int tbl;
int i;
u32 eflags, cid;
for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
alloc_tbl = qcom_smem_get(edge->remote_pid,
smem_items[tbl].alloc_tbl_id, NULL);
if (IS_ERR(alloc_tbl))
continue;
for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
entry = &alloc_tbl[i];
eflags = le32_to_cpu(entry->flags);
if (test_bit(i, edge->allocated[tbl]))
continue;
if (entry->ref_count == 0)
continue;
if (!entry->name[0])
continue;
if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
continue;
if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
continue;
cid = le32_to_cpu(entry->cid);
info_id = smem_items[tbl].info_base_id + cid;
fifo_id = smem_items[tbl].fifo_base_id + cid;
channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
if (IS_ERR(channel))
continue;
spin_lock_irqsave(&edge->channels_lock, flags);
list_add(&channel->list, &edge->channels);
spin_unlock_irqrestore(&edge->channels_lock, flags);
dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
set_bit(i, edge->allocated[tbl]);
wake_up_interruptible_all(&edge->new_channel_event);
}
}
schedule_work(&edge->state_work);
}
/*
* This per edge worker scans smem for any new channels and register these. It
* then scans all registered channels for state changes that should be handled
* by creating or destroying smd client devices for the registered channels.
*
* LOCKING: edge->channels_lock only needs to cover the list operations, as the
* worker is killed before any channels are deallocated
*/
static void qcom_channel_state_worker(struct work_struct *work)
{
struct qcom_smd_channel *channel;
struct qcom_smd_edge *edge = container_of(work,
struct qcom_smd_edge,
state_work);
struct rpmsg_channel_info chinfo;
unsigned remote_state;
unsigned long flags;
/*
* Register a device for any closed channel where the remote processor
* is showing interest in opening the channel.
*/
spin_lock_irqsave(&edge->channels_lock, flags);
list_for_each_entry(channel, &edge->channels, list) {
if (channel->state != SMD_CHANNEL_CLOSED)
continue;
/*
* Always open rpm_requests, even when already opened which is
* required on some SoCs like msm8953.
*/
remote_state = GET_RX_CHANNEL_INFO(channel, state);
if (remote_state != SMD_CHANNEL_OPENING &&
remote_state != SMD_CHANNEL_OPENED &&
strcmp(channel->name, "rpm_requests"))
continue;
if (channel->registered)
continue;
spin_unlock_irqrestore(&edge->channels_lock, flags);
qcom_smd_create_device(channel);
spin_lock_irqsave(&edge->channels_lock, flags);
channel->registered = true;
}
/*
* Unregister the device for any channel that is opened where the
* remote processor is closing the channel.
*/
list_for_each_entry(channel, &edge->channels, list) {
if (channel->state != SMD_CHANNEL_OPENING &&
channel->state != SMD_CHANNEL_OPENED)
continue;
remote_state = GET_RX_CHANNEL_INFO(channel, state);
if (remote_state == SMD_CHANNEL_OPENING ||
remote_state == SMD_CHANNEL_OPENED)
continue;
spin_unlock_irqrestore(&edge->channels_lock, flags);
strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
chinfo.src = RPMSG_ADDR_ANY;
chinfo.dst = RPMSG_ADDR_ANY;
rpmsg_unregister_device(&edge->dev, &chinfo);
channel->registered = false;
spin_lock_irqsave(&edge->channels_lock, flags);
}
spin_unlock_irqrestore(&edge->channels_lock, flags);
}
/*
* Parses an of_node describing an edge.
*/
static int qcom_smd_parse_edge(struct device *dev,
struct device_node *node,
struct qcom_smd_edge *edge)
{
struct device_node *syscon_np;
const char *key;
int irq;
int ret;
INIT_LIST_HEAD(&edge->channels);
spin_lock_init(&edge->channels_lock);
INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
INIT_WORK(&edge->state_work, qcom_channel_state_worker);
edge->of_node = of_node_get(node);
key = "qcom,smd-edge";
ret = of_property_read_u32(node, key, &edge->edge_id);
if (ret) {
dev_err(dev, "edge missing %s property\n", key);
goto put_node;
}
edge->remote_pid = QCOM_SMEM_HOST_ANY;
key = "qcom,remote-pid";
of_property_read_u32(node, key, &edge->remote_pid);
edge->mbox_client.dev = dev;
edge->mbox_client.knows_txdone = true;
edge->mbox_chan = mbox_request_channel(&edge->mbox_client, 0);
if (IS_ERR(edge->mbox_chan)) {
if (PTR_ERR(edge->mbox_chan) != -ENODEV) {
ret = PTR_ERR(edge->mbox_chan);
goto put_node;
}
edge->mbox_chan = NULL;
syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
if (!syscon_np) {
dev_err(dev, "no qcom,ipc node\n");
ret = -ENODEV;
goto put_node;
}
edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
of_node_put(syscon_np);
if (IS_ERR(edge->ipc_regmap)) {
ret = PTR_ERR(edge->ipc_regmap);
goto put_node;
}
key = "qcom,ipc";
ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
if (ret < 0) {
dev_err(dev, "no offset in %s\n", key);
goto put_node;
}
ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
if (ret < 0) {
dev_err(dev, "no bit in %s\n", key);
goto put_node;
}
}
ret = of_property_read_string(node, "label", &edge->name);
if (ret < 0)
edge->name = node->name;
irq = irq_of_parse_and_map(node, 0);
if (!irq) {
dev_err(dev, "required smd interrupt missing\n");
ret = -EINVAL;
goto put_node;
}
ret = devm_request_irq(dev, irq,
qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
node->name, edge);
if (ret) {
dev_err(dev, "failed to request smd irq\n");
goto put_node;
}
edge->irq = irq;
return 0;
put_node:
of_node_put(node);
edge->of_node = NULL;
return ret;
}
/*
* Release function for an edge.
* Reset the state of each associated channel and free the edge context.
*/
static void qcom_smd_edge_release(struct device *dev)
{
struct qcom_smd_channel *channel, *tmp;
struct qcom_smd_edge *edge = to_smd_edge(dev);
list_for_each_entry_safe(channel, tmp, &edge->channels, list) {
list_del(&channel->list);
kfree(channel->name);
kfree(channel);
}
kfree(edge);
}
static ssize_t rpmsg_name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct qcom_smd_edge *edge = to_smd_edge(dev);
return sprintf(buf, "%s\n", edge->name);
}
static DEVICE_ATTR_RO(rpmsg_name);
static struct attribute *qcom_smd_edge_attrs[] = {
&dev_attr_rpmsg_name.attr,
NULL
};
ATTRIBUTE_GROUPS(qcom_smd_edge);
/**
* qcom_smd_register_edge() - register an edge based on an device_node
* @parent: parent device for the edge
* @node: device_node describing the edge
*
* Return: an edge reference, or negative ERR_PTR() on failure.
*/
struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
struct device_node *node)
{
struct qcom_smd_edge *edge;
int ret;
edge = kzalloc(sizeof(*edge), GFP_KERNEL);
if (!edge)
return ERR_PTR(-ENOMEM);
init_waitqueue_head(&edge->new_channel_event);
edge->dev.parent = parent;
edge->dev.release = qcom_smd_edge_release;
edge->dev.of_node = node;
edge->dev.groups = qcom_smd_edge_groups;
dev_set_name(&edge->dev, "%s:%pOFn", dev_name(parent), node);
ret = device_register(&edge->dev);
if (ret) {
pr_err("failed to register smd edge\n");
put_device(&edge->dev);
return ERR_PTR(ret);
}
ret = qcom_smd_parse_edge(&edge->dev, node, edge);
if (ret) {
dev_err(&edge->dev, "failed to parse smd edge\n");
goto unregister_dev;
}
ret = qcom_smd_create_chrdev(edge);
if (ret) {
dev_err(&edge->dev, "failed to register chrdev for edge\n");
goto unregister_dev;
}
schedule_work(&edge->scan_work);
return edge;
unregister_dev:
if (!IS_ERR_OR_NULL(edge->mbox_chan))
mbox_free_channel(edge->mbox_chan);
device_unregister(&edge->dev);
return ERR_PTR(ret);
}
EXPORT_SYMBOL(qcom_smd_register_edge);
static int qcom_smd_remove_device(struct device *dev, void *data)
{
device_unregister(dev);
return 0;
}
/**
* qcom_smd_unregister_edge() - release an edge and its children
* @edge: edge reference acquired from qcom_smd_register_edge
*/
void qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
{
int ret;
disable_irq(edge->irq);
cancel_work_sync(&edge->scan_work);
cancel_work_sync(&edge->state_work);
ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
if (ret)
dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
mbox_free_channel(edge->mbox_chan);
device_unregister(&edge->dev);
}
EXPORT_SYMBOL(qcom_smd_unregister_edge);
static int qcom_smd_probe(struct platform_device *pdev)
{
struct device_node *node;
void *p;
/* Wait for smem */
p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
if (PTR_ERR(p) == -EPROBE_DEFER)
return PTR_ERR(p);
for_each_available_child_of_node(pdev->dev.of_node, node)
qcom_smd_register_edge(&pdev->dev, node);
return 0;
}
static int qcom_smd_remove_edge(struct device *dev, void *data)
{
struct qcom_smd_edge *edge = to_smd_edge(dev);
qcom_smd_unregister_edge(edge);
return 0;
}
/*
* Shut down all smd clients by making sure that each edge stops processing
* events and scanning for new channels, then call destroy on the devices.
*/
static void qcom_smd_remove(struct platform_device *pdev)
{
/*
* qcom_smd_remove_edge always returns zero, so there is no need to
* check the return value of device_for_each_child.
*/
device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
}
static const struct of_device_id qcom_smd_of_match[] = {
{ .compatible = "qcom,smd" },
{}
};
MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
static struct platform_driver qcom_smd_driver = {
.probe = qcom_smd_probe,
.remove_new = qcom_smd_remove,
.driver = {
.name = "qcom-smd",
.of_match_table = qcom_smd_of_match,
},
};
static int __init qcom_smd_init(void)
{
return platform_driver_register(&qcom_smd_driver);
}
arch_initcall(qcom_smd_init);
static void __exit qcom_smd_exit(void)
{
platform_driver_unregister(&qcom_smd_driver);
}
module_exit(qcom_smd_exit);
MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
MODULE_LICENSE("GPL v2");