mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
9d24322e88
Introduced in a PCIe r6.0, sec 6.30, DOE provides a config space based mailbox with standard protocol discovery. Each mailbox is accessed through a DOE Extended Capability. Each DOE mailbox must support the DOE discovery protocol in addition to any number of additional protocols. Define core PCIe functionality to manage a single PCIe DOE mailbox at a defined config space offset. Functionality includes iterating, creating, query of supported protocol, and task submission. Destruction of the mailboxes is device managed. Cc: "Li, Ming" <ming4.li@intel.com> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Acked-by: Bjorn Helgaas <helgaas@kernel.org> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Co-developed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Link: https://lore.kernel.org/r/20220719205249.566684-4-ira.weiny@intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com>
537 lines
14 KiB
C
537 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Data Object Exchange
|
|
* PCIe r6.0, sec 6.30 DOE
|
|
*
|
|
* Copyright (C) 2021 Huawei
|
|
* Jonathan Cameron <Jonathan.Cameron@huawei.com>
|
|
*
|
|
* Copyright (C) 2022 Intel Corporation
|
|
* Ira Weiny <ira.weiny@intel.com>
|
|
*/
|
|
|
|
#define dev_fmt(fmt) "DOE: " fmt
|
|
|
|
#include <linux/bitfield.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/pci-doe.h>
|
|
#include <linux/workqueue.h>
|
|
|
|
#define PCI_DOE_PROTOCOL_DISCOVERY 0
|
|
|
|
/* Timeout of 1 second from 6.30.2 Operation, PCI Spec r6.0 */
|
|
#define PCI_DOE_TIMEOUT HZ
|
|
#define PCI_DOE_POLL_INTERVAL (PCI_DOE_TIMEOUT / 128)
|
|
|
|
#define PCI_DOE_FLAG_CANCEL 0
|
|
#define PCI_DOE_FLAG_DEAD 1
|
|
|
|
/**
|
|
* struct pci_doe_mb - State for a single DOE mailbox
|
|
*
|
|
* This state is used to manage a single DOE mailbox capability. All fields
|
|
* should be considered opaque to the consumers and the structure passed into
|
|
* the helpers below after being created by devm_pci_doe_create()
|
|
*
|
|
* @pdev: PCI device this mailbox belongs to
|
|
* @cap_offset: Capability offset
|
|
* @prots: Array of protocols supported (encoded as long values)
|
|
* @wq: Wait queue for work item
|
|
* @work_queue: Queue of pci_doe_work items
|
|
* @flags: Bit array of PCI_DOE_FLAG_* flags
|
|
*/
|
|
struct pci_doe_mb {
|
|
struct pci_dev *pdev;
|
|
u16 cap_offset;
|
|
struct xarray prots;
|
|
|
|
wait_queue_head_t wq;
|
|
struct workqueue_struct *work_queue;
|
|
unsigned long flags;
|
|
};
|
|
|
|
static int pci_doe_wait(struct pci_doe_mb *doe_mb, unsigned long timeout)
|
|
{
|
|
if (wait_event_timeout(doe_mb->wq,
|
|
test_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags),
|
|
timeout))
|
|
return -EIO;
|
|
return 0;
|
|
}
|
|
|
|
static void pci_doe_write_ctrl(struct pci_doe_mb *doe_mb, u32 val)
|
|
{
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
int offset = doe_mb->cap_offset;
|
|
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_CTRL, val);
|
|
}
|
|
|
|
static int pci_doe_abort(struct pci_doe_mb *doe_mb)
|
|
{
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
int offset = doe_mb->cap_offset;
|
|
unsigned long timeout_jiffies;
|
|
|
|
pci_dbg(pdev, "[%x] Issuing Abort\n", offset);
|
|
|
|
timeout_jiffies = jiffies + PCI_DOE_TIMEOUT;
|
|
pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_ABORT);
|
|
|
|
do {
|
|
int rc;
|
|
u32 val;
|
|
|
|
rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL);
|
|
if (rc)
|
|
return rc;
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
|
|
|
|
/* Abort success! */
|
|
if (!FIELD_GET(PCI_DOE_STATUS_ERROR, val) &&
|
|
!FIELD_GET(PCI_DOE_STATUS_BUSY, val))
|
|
return 0;
|
|
|
|
} while (!time_after(jiffies, timeout_jiffies));
|
|
|
|
/* Abort has timed out and the MB is dead */
|
|
pci_err(pdev, "[%x] ABORT timed out\n", offset);
|
|
return -EIO;
|
|
}
|
|
|
|
static int pci_doe_send_req(struct pci_doe_mb *doe_mb,
|
|
struct pci_doe_task *task)
|
|
{
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
int offset = doe_mb->cap_offset;
|
|
u32 val;
|
|
int i;
|
|
|
|
/*
|
|
* Check the DOE busy bit is not set. If it is set, this could indicate
|
|
* someone other than Linux (e.g. firmware) is using the mailbox. Note
|
|
* it is expected that firmware and OS will negotiate access rights via
|
|
* an, as yet to be defined, method.
|
|
*/
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
|
|
if (FIELD_GET(PCI_DOE_STATUS_BUSY, val))
|
|
return -EBUSY;
|
|
|
|
if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
|
|
return -EIO;
|
|
|
|
/* Write DOE Header */
|
|
val = FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_VID, task->prot.vid) |
|
|
FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, task->prot.type);
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_WRITE, val);
|
|
/* Length is 2 DW of header + length of payload in DW */
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
|
|
FIELD_PREP(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH,
|
|
2 + task->request_pl_sz /
|
|
sizeof(u32)));
|
|
for (i = 0; i < task->request_pl_sz / sizeof(u32); i++)
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_WRITE,
|
|
task->request_pl[i]);
|
|
|
|
pci_doe_write_ctrl(doe_mb, PCI_DOE_CTRL_GO);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool pci_doe_data_obj_ready(struct pci_doe_mb *doe_mb)
|
|
{
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
int offset = doe_mb->cap_offset;
|
|
u32 val;
|
|
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
|
|
if (FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static int pci_doe_recv_resp(struct pci_doe_mb *doe_mb, struct pci_doe_task *task)
|
|
{
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
int offset = doe_mb->cap_offset;
|
|
size_t length, payload_length;
|
|
u32 val;
|
|
int i;
|
|
|
|
/* Read the first dword to get the protocol */
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
|
|
if ((FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val) != task->prot.vid) ||
|
|
(FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val) != task->prot.type)) {
|
|
dev_err_ratelimited(&pdev->dev, "[%x] expected [VID, Protocol] = [%04x, %02x], got [%04x, %02x]\n",
|
|
doe_mb->cap_offset, task->prot.vid, task->prot.type,
|
|
FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_VID, val),
|
|
FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_1_TYPE, val));
|
|
return -EIO;
|
|
}
|
|
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
|
|
/* Read the second dword to get the length */
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
|
|
|
|
length = FIELD_GET(PCI_DOE_DATA_OBJECT_HEADER_2_LENGTH, val);
|
|
if (length > SZ_1M || length < 2)
|
|
return -EIO;
|
|
|
|
/* First 2 dwords have already been read */
|
|
length -= 2;
|
|
payload_length = min(length, task->response_pl_sz / sizeof(u32));
|
|
/* Read the rest of the response payload */
|
|
for (i = 0; i < payload_length; i++) {
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_READ,
|
|
&task->response_pl[i]);
|
|
/* Prior to the last ack, ensure Data Object Ready */
|
|
if (i == (payload_length - 1) && !pci_doe_data_obj_ready(doe_mb))
|
|
return -EIO;
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
|
|
}
|
|
|
|
/* Flush excess length */
|
|
for (; i < length; i++) {
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_READ, &val);
|
|
pci_write_config_dword(pdev, offset + PCI_DOE_READ, 0);
|
|
}
|
|
|
|
/* Final error check to pick up on any since Data Object Ready */
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
|
|
if (FIELD_GET(PCI_DOE_STATUS_ERROR, val))
|
|
return -EIO;
|
|
|
|
return min(length, task->response_pl_sz / sizeof(u32)) * sizeof(u32);
|
|
}
|
|
|
|
static void signal_task_complete(struct pci_doe_task *task, int rv)
|
|
{
|
|
task->rv = rv;
|
|
task->complete(task);
|
|
}
|
|
|
|
static void signal_task_abort(struct pci_doe_task *task, int rv)
|
|
{
|
|
struct pci_doe_mb *doe_mb = task->doe_mb;
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
|
|
if (pci_doe_abort(doe_mb)) {
|
|
/*
|
|
* If the device can't process an abort; set the mailbox dead
|
|
* - no more submissions
|
|
*/
|
|
pci_err(pdev, "[%x] Abort failed marking mailbox dead\n",
|
|
doe_mb->cap_offset);
|
|
set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags);
|
|
}
|
|
signal_task_complete(task, rv);
|
|
}
|
|
|
|
static void doe_statemachine_work(struct work_struct *work)
|
|
{
|
|
struct pci_doe_task *task = container_of(work, struct pci_doe_task,
|
|
work);
|
|
struct pci_doe_mb *doe_mb = task->doe_mb;
|
|
struct pci_dev *pdev = doe_mb->pdev;
|
|
int offset = doe_mb->cap_offset;
|
|
unsigned long timeout_jiffies;
|
|
u32 val;
|
|
int rc;
|
|
|
|
if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags)) {
|
|
signal_task_complete(task, -EIO);
|
|
return;
|
|
}
|
|
|
|
/* Send request */
|
|
rc = pci_doe_send_req(doe_mb, task);
|
|
if (rc) {
|
|
/*
|
|
* The specification does not provide any guidance on how to
|
|
* resolve conflicting requests from other entities.
|
|
* Furthermore, it is likely that busy will not be detected
|
|
* most of the time. Flag any detection of status busy with an
|
|
* error.
|
|
*/
|
|
if (rc == -EBUSY)
|
|
dev_err_ratelimited(&pdev->dev, "[%x] busy detected; another entity is sending conflicting requests\n",
|
|
offset);
|
|
signal_task_abort(task, rc);
|
|
return;
|
|
}
|
|
|
|
timeout_jiffies = jiffies + PCI_DOE_TIMEOUT;
|
|
/* Poll for response */
|
|
retry_resp:
|
|
pci_read_config_dword(pdev, offset + PCI_DOE_STATUS, &val);
|
|
if (FIELD_GET(PCI_DOE_STATUS_ERROR, val)) {
|
|
signal_task_abort(task, -EIO);
|
|
return;
|
|
}
|
|
|
|
if (!FIELD_GET(PCI_DOE_STATUS_DATA_OBJECT_READY, val)) {
|
|
if (time_after(jiffies, timeout_jiffies)) {
|
|
signal_task_abort(task, -EIO);
|
|
return;
|
|
}
|
|
rc = pci_doe_wait(doe_mb, PCI_DOE_POLL_INTERVAL);
|
|
if (rc) {
|
|
signal_task_abort(task, rc);
|
|
return;
|
|
}
|
|
goto retry_resp;
|
|
}
|
|
|
|
rc = pci_doe_recv_resp(doe_mb, task);
|
|
if (rc < 0) {
|
|
signal_task_abort(task, rc);
|
|
return;
|
|
}
|
|
|
|
signal_task_complete(task, rc);
|
|
}
|
|
|
|
static void pci_doe_task_complete(struct pci_doe_task *task)
|
|
{
|
|
complete(task->private);
|
|
}
|
|
|
|
static int pci_doe_discovery(struct pci_doe_mb *doe_mb, u8 *index, u16 *vid,
|
|
u8 *protocol)
|
|
{
|
|
u32 request_pl = FIELD_PREP(PCI_DOE_DATA_OBJECT_DISC_REQ_3_INDEX,
|
|
*index);
|
|
u32 response_pl;
|
|
DECLARE_COMPLETION_ONSTACK(c);
|
|
struct pci_doe_task task = {
|
|
.prot.vid = PCI_VENDOR_ID_PCI_SIG,
|
|
.prot.type = PCI_DOE_PROTOCOL_DISCOVERY,
|
|
.request_pl = &request_pl,
|
|
.request_pl_sz = sizeof(request_pl),
|
|
.response_pl = &response_pl,
|
|
.response_pl_sz = sizeof(response_pl),
|
|
.complete = pci_doe_task_complete,
|
|
.private = &c,
|
|
};
|
|
int rc;
|
|
|
|
rc = pci_doe_submit_task(doe_mb, &task);
|
|
if (rc < 0)
|
|
return rc;
|
|
|
|
wait_for_completion(&c);
|
|
|
|
if (task.rv != sizeof(response_pl))
|
|
return -EIO;
|
|
|
|
*vid = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_VID, response_pl);
|
|
*protocol = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_PROTOCOL,
|
|
response_pl);
|
|
*index = FIELD_GET(PCI_DOE_DATA_OBJECT_DISC_RSP_3_NEXT_INDEX,
|
|
response_pl);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void *pci_doe_xa_prot_entry(u16 vid, u8 prot)
|
|
{
|
|
return xa_mk_value((vid << 8) | prot);
|
|
}
|
|
|
|
static int pci_doe_cache_protocols(struct pci_doe_mb *doe_mb)
|
|
{
|
|
u8 index = 0;
|
|
u8 xa_idx = 0;
|
|
|
|
do {
|
|
int rc;
|
|
u16 vid;
|
|
u8 prot;
|
|
|
|
rc = pci_doe_discovery(doe_mb, &index, &vid, &prot);
|
|
if (rc)
|
|
return rc;
|
|
|
|
pci_dbg(doe_mb->pdev,
|
|
"[%x] Found protocol %d vid: %x prot: %x\n",
|
|
doe_mb->cap_offset, xa_idx, vid, prot);
|
|
|
|
rc = xa_insert(&doe_mb->prots, xa_idx++,
|
|
pci_doe_xa_prot_entry(vid, prot), GFP_KERNEL);
|
|
if (rc)
|
|
return rc;
|
|
} while (index);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void pci_doe_xa_destroy(void *mb)
|
|
{
|
|
struct pci_doe_mb *doe_mb = mb;
|
|
|
|
xa_destroy(&doe_mb->prots);
|
|
}
|
|
|
|
static void pci_doe_destroy_workqueue(void *mb)
|
|
{
|
|
struct pci_doe_mb *doe_mb = mb;
|
|
|
|
destroy_workqueue(doe_mb->work_queue);
|
|
}
|
|
|
|
static void pci_doe_flush_mb(void *mb)
|
|
{
|
|
struct pci_doe_mb *doe_mb = mb;
|
|
|
|
/* Stop all pending work items from starting */
|
|
set_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags);
|
|
|
|
/* Cancel an in progress work item, if necessary */
|
|
set_bit(PCI_DOE_FLAG_CANCEL, &doe_mb->flags);
|
|
wake_up(&doe_mb->wq);
|
|
|
|
/* Flush all work items */
|
|
flush_workqueue(doe_mb->work_queue);
|
|
}
|
|
|
|
/**
|
|
* pcim_doe_create_mb() - Create a DOE mailbox object
|
|
*
|
|
* @pdev: PCI device to create the DOE mailbox for
|
|
* @cap_offset: Offset of the DOE mailbox
|
|
*
|
|
* Create a single mailbox object to manage the mailbox protocol at the
|
|
* cap_offset specified.
|
|
*
|
|
* RETURNS: created mailbox object on success
|
|
* ERR_PTR(-errno) on failure
|
|
*/
|
|
struct pci_doe_mb *pcim_doe_create_mb(struct pci_dev *pdev, u16 cap_offset)
|
|
{
|
|
struct pci_doe_mb *doe_mb;
|
|
struct device *dev = &pdev->dev;
|
|
int rc;
|
|
|
|
doe_mb = devm_kzalloc(dev, sizeof(*doe_mb), GFP_KERNEL);
|
|
if (!doe_mb)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
doe_mb->pdev = pdev;
|
|
doe_mb->cap_offset = cap_offset;
|
|
init_waitqueue_head(&doe_mb->wq);
|
|
|
|
xa_init(&doe_mb->prots);
|
|
rc = devm_add_action(dev, pci_doe_xa_destroy, doe_mb);
|
|
if (rc)
|
|
return ERR_PTR(rc);
|
|
|
|
doe_mb->work_queue = alloc_ordered_workqueue("%s %s DOE [%x]", 0,
|
|
dev_driver_string(&pdev->dev),
|
|
pci_name(pdev),
|
|
doe_mb->cap_offset);
|
|
if (!doe_mb->work_queue) {
|
|
pci_err(pdev, "[%x] failed to allocate work queue\n",
|
|
doe_mb->cap_offset);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
rc = devm_add_action_or_reset(dev, pci_doe_destroy_workqueue, doe_mb);
|
|
if (rc)
|
|
return ERR_PTR(rc);
|
|
|
|
/* Reset the mailbox by issuing an abort */
|
|
rc = pci_doe_abort(doe_mb);
|
|
if (rc) {
|
|
pci_err(pdev, "[%x] failed to reset mailbox with abort command : %d\n",
|
|
doe_mb->cap_offset, rc);
|
|
return ERR_PTR(rc);
|
|
}
|
|
|
|
/*
|
|
* The state machine and the mailbox should be in sync now;
|
|
* Set up mailbox flush prior to using the mailbox to query protocols.
|
|
*/
|
|
rc = devm_add_action_or_reset(dev, pci_doe_flush_mb, doe_mb);
|
|
if (rc)
|
|
return ERR_PTR(rc);
|
|
|
|
rc = pci_doe_cache_protocols(doe_mb);
|
|
if (rc) {
|
|
pci_err(pdev, "[%x] failed to cache protocols : %d\n",
|
|
doe_mb->cap_offset, rc);
|
|
return ERR_PTR(rc);
|
|
}
|
|
|
|
return doe_mb;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pcim_doe_create_mb);
|
|
|
|
/**
|
|
* pci_doe_supports_prot() - Return if the DOE instance supports the given
|
|
* protocol
|
|
* @doe_mb: DOE mailbox capability to query
|
|
* @vid: Protocol Vendor ID
|
|
* @type: Protocol type
|
|
*
|
|
* RETURNS: True if the DOE mailbox supports the protocol specified
|
|
*/
|
|
bool pci_doe_supports_prot(struct pci_doe_mb *doe_mb, u16 vid, u8 type)
|
|
{
|
|
unsigned long index;
|
|
void *entry;
|
|
|
|
/* The discovery protocol must always be supported */
|
|
if (vid == PCI_VENDOR_ID_PCI_SIG && type == PCI_DOE_PROTOCOL_DISCOVERY)
|
|
return true;
|
|
|
|
xa_for_each(&doe_mb->prots, index, entry)
|
|
if (entry == pci_doe_xa_prot_entry(vid, type))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_doe_supports_prot);
|
|
|
|
/**
|
|
* pci_doe_submit_task() - Submit a task to be processed by the state machine
|
|
*
|
|
* @doe_mb: DOE mailbox capability to submit to
|
|
* @task: task to be queued
|
|
*
|
|
* Submit a DOE task (request/response) to the DOE mailbox to be processed.
|
|
* Returns upon queueing the task object. If the queue is full this function
|
|
* will sleep until there is room in the queue.
|
|
*
|
|
* task->complete will be called when the state machine is done processing this
|
|
* task.
|
|
*
|
|
* Excess data will be discarded.
|
|
*
|
|
* RETURNS: 0 when task has been successfully queued, -ERRNO on error
|
|
*/
|
|
int pci_doe_submit_task(struct pci_doe_mb *doe_mb, struct pci_doe_task *task)
|
|
{
|
|
if (!pci_doe_supports_prot(doe_mb, task->prot.vid, task->prot.type))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* DOE requests must be a whole number of DW and the response needs to
|
|
* be big enough for at least 1 DW
|
|
*/
|
|
if (task->request_pl_sz % sizeof(u32) ||
|
|
task->response_pl_sz < sizeof(u32))
|
|
return -EINVAL;
|
|
|
|
if (test_bit(PCI_DOE_FLAG_DEAD, &doe_mb->flags))
|
|
return -EIO;
|
|
|
|
task->doe_mb = doe_mb;
|
|
INIT_WORK(&task->work, doe_statemachine_work);
|
|
queue_work(doe_mb->work_queue, &task->work);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pci_doe_submit_task);
|