// SPDX-License-Identifier: MIT
/*
* Copyright © 2016-2019 Intel Corporation
*/
#include <linux/circ_buf.h>
#include <linux/ktime.h>
#include <linux/time64.h>
#include <linux/string_helpers.h>
#include <linux/timekeeping.h>
#include "i915_drv.h"
#include "intel_guc_ct.h"
#include "intel_guc_print.h"
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
enum {
CT_DEAD_ALIVE = 0,
CT_DEAD_SETUP,
CT_DEAD_WRITE,
CT_DEAD_DEADLOCK,
CT_DEAD_H2G_HAS_ROOM,
CT_DEAD_READ,
CT_DEAD_PROCESS_FAILED,
};
static void ct_dead_ct_worker_func(struct work_struct *w);
#define CT_DEAD(ct, reason) \
do { \
if (!(ct)->dead_ct_reported) { \
(ct)->dead_ct_reason |= 1 << CT_DEAD_##reason; \
queue_work(system_unbound_wq, &(ct)->dead_ct_worker); \
} \
} while (0)
#else
#define CT_DEAD(ct, reason) do { } while (0)
#endif
static inline struct intel_guc *ct_to_guc(struct intel_guc_ct *ct)
{
return container_of(ct, struct intel_guc, ct);
}
#define CT_ERROR(_ct, _fmt, ...) \
guc_err(ct_to_guc(_ct), "CT: " _fmt, ##__VA_ARGS__)
#ifdef CONFIG_DRM_I915_DEBUG_GUC
#define CT_DEBUG(_ct, _fmt, ...) \
guc_dbg(ct_to_guc(_ct), "CT: " _fmt, ##__VA_ARGS__)
#else
#define CT_DEBUG(...) do { } while (0)
#endif
#define CT_PROBE_ERROR(_ct, _fmt, ...) \
guc_probe_error(ct_to_guc(ct), "CT: " _fmt, ##__VA_ARGS__)
/**
* DOC: CTB Blob
*
* We allocate single blob to hold both CTB descriptors and buffers:
*
* +--------+-----------------------------------------------+------+
* | offset | contents | size |
* +========+===============================================+======+
* | 0x0000 | H2G `CTB Descriptor`_ (send) | |
* +--------+-----------------------------------------------+ 4K |
* | 0x0800 | G2H `CTB Descriptor`_ (recv) | |
* +--------+-----------------------------------------------+------+
* | 0x1000 | H2G `CT Buffer`_ (send) | n*4K |
* | | | |
* +--------+-----------------------------------------------+------+
* | 0x1000 | G2H `CT Buffer`_ (recv) | m*4K |
* | + n*4K | | |
* +--------+-----------------------------------------------+------+
*
* Size of each `CT Buffer`_ must be multiple of 4K.
* We don't expect too many messages in flight at any time, unless we are
* using the GuC submission. In that case each request requires a minimum
* 2 dwords which gives us a maximum 256 queue'd requests. Hopefully this
* enough space to avoid backpressure on the driver. We increase the size
* of the receive buffer (relative to the send) to ensure a G2H response
* CTB has a landing spot.
*/
#define CTB_DESC_SIZE ALIGN(sizeof(struct guc_ct_buffer_desc), SZ_2K)
#define CTB_H2G_BUFFER_SIZE (SZ_4K)
#define CTB_G2H_BUFFER_SIZE (4 * CTB_H2G_BUFFER_SIZE)
#define G2H_ROOM_BUFFER_SIZE (CTB_G2H_BUFFER_SIZE / 4)
struct ct_request {
struct list_head link;
u32 fence;
u32 status;
u32 response_len;
u32 *response_buf;
};
struct ct_incoming_msg {
struct list_head link;
u32 size;
u32 msg[] __counted_by(size);
};
enum { CTB_SEND = 0, CTB_RECV = 1 };
enum { CTB_OWNER_HOST = 0 };
/*
* Some H2G commands involve a synchronous response that the driver needs
* to wait for. In such cases, a timeout is required to prevent the driver
* from waiting forever in the case of an error (either no error response
* is defined in the protocol or something has died and requires a reset).
* The specific command may be defined as having a time bound response but
* the CT is a queue and that time guarantee only starts from the point
* when the command reaches the head of the queue and is processed by GuC.
*
* Ideally there would be a helper to report the progress of a given
* command through the CT. However, that would require a significant
* amount of work in the CT layer. In the meantime, provide a reasonable
* estimation of the worst case latency it should take for the entire
* queue to drain. And therefore, how long a caller should wait before
* giving up on their request. The current estimate is based on empirical
* measurement of a test that fills the buffer with context creation and
* destruction requests as they seem to be the slowest operation.
*/
long intel_guc_ct_max_queue_time_jiffies(void)
{
/*
* A 4KB buffer full of context destroy commands takes a little
* over a second to process so bump that to 2s to be super safe.
*/
return (CTB_H2G_BUFFER_SIZE * HZ) / SZ_2K;
}
static void ct_receive_tasklet_func(struct tasklet_struct *t);
static void ct_incoming_request_worker_func(struct work_struct *w);
/**
* intel_guc_ct_init_early - Initialize CT state without requiring device access
* @ct: pointer to CT struct
*/
void intel_guc_ct_init_early(struct intel_guc_ct *ct)
{
spin_lock_init(&ct->ctbs.send.lock);
spin_lock_init(&ct->ctbs.recv.lock);
spin_lock_init(&ct->requests.lock);
INIT_LIST_HEAD(&ct->requests.pending);
INIT_LIST_HEAD(&ct->requests.incoming);
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
INIT_WORK(&ct->dead_ct_worker, ct_dead_ct_worker_func);
#endif
INIT_WORK(&ct->requests.worker, ct_incoming_request_worker_func);
tasklet_setup(&ct->receive_tasklet, ct_receive_tasklet_func);
init_waitqueue_head(&ct->wq);
}
static void guc_ct_buffer_desc_init(struct guc_ct_buffer_desc *desc)
{
memset(desc, 0, sizeof(*desc));
}
static void guc_ct_buffer_reset(struct intel_guc_ct_buffer *ctb)
{
u32 space;
ctb->broken = false;
ctb->tail = 0;
ctb->head = 0;
space = CIRC_SPACE(ctb->tail, ctb->head, ctb->size) - ctb->resv_space;
atomic_set(&ctb->space, space);
guc_ct_buffer_desc_init(ctb->desc);
}
static void guc_ct_buffer_init(struct intel_guc_ct_buffer *ctb,
struct guc_ct_buffer_desc *desc,
u32 *cmds, u32 size_in_bytes, u32 resv_space)
{
GEM_BUG_ON(size_in_bytes % 4);
ctb->desc = desc;
ctb->cmds = cmds;
ctb->size = size_in_bytes / 4;
ctb->resv_space = resv_space / 4;
guc_ct_buffer_reset(ctb);
}
static int guc_action_control_ctb(struct intel_guc *guc, u32 control)
{
u32 request[HOST2GUC_CONTROL_CTB_REQUEST_MSG_LEN] = {
FIELD_PREP(GUC_HXG_MSG_0_ORIGIN, GUC_HXG_ORIGIN_HOST) |
FIELD_PREP(GUC_HXG_MSG_0_TYPE, GUC_HXG_TYPE_REQUEST) |
FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION, GUC_ACTION_HOST2GUC_CONTROL_CTB),
FIELD_PREP(HOST2GUC_CONTROL_CTB_REQUEST_MSG_1_CONTROL, control),
};
int ret;
GEM_BUG_ON(control != GUC_CTB_CONTROL_DISABLE && control != GUC_CTB_CONTROL_ENABLE);
/* CT control must go over MMIO */
ret = intel_guc_send_mmio(guc, request, ARRAY_SIZE(request), NULL, 0);
return ret > 0 ? -EPROTO : ret;
}
static int ct_control_enable(struct intel_guc_ct *ct, bool enable)
{
int err;
err = guc_action_control_ctb(ct_to_guc(ct), enable ?
GUC_CTB_CONTROL_ENABLE : GUC_CTB_CONTROL_DISABLE);
if (unlikely(err))
CT_PROBE_ERROR(ct, "Failed to control/%s CTB (%pe)\n",
str_enable_disable(enable), ERR_PTR(err));
return err;
}
static int ct_register_buffer(struct intel_guc_ct *ct, bool send,
u32 desc_addr, u32 buff_addr, u32 size)
{
int err;
err = intel_guc_self_cfg64(ct_to_guc(ct), send ?
GUC_KLV_SELF_CFG_H2G_CTB_DESCRIPTOR_ADDR_KEY :
GUC_KLV_SELF_CFG_G2H_CTB_DESCRIPTOR_ADDR_KEY,
desc_addr);
if (unlikely(err))
goto failed;
err = intel_guc_self_cfg64(ct_to_guc(ct), send ?
GUC_KLV_SELF_CFG_H2G_CTB_ADDR_KEY :
GUC_KLV_SELF_CFG_G2H_CTB_ADDR_KEY,
buff_addr);
if (unlikely(err))
goto failed;
err = intel_guc_self_cfg32(ct_to_guc(ct), send ?
GUC_KLV_SELF_CFG_H2G_CTB_SIZE_KEY :
GUC_KLV_SELF_CFG_G2H_CTB_SIZE_KEY,
size);
if (unlikely(err))
failed:
CT_PROBE_ERROR(ct, "Failed to register %s buffer (%pe)\n",
send ? "SEND" : "RECV", ERR_PTR(err));
return err;
}
/**
* intel_guc_ct_init - Init buffer-based communication
* @ct: pointer to CT struct
*
* Allocate memory required for buffer-based communication.
*
* Return: 0 on success, a negative errno code on failure.
*/
int intel_guc_ct_init(struct intel_guc_ct *ct)
{
struct intel_guc *guc = ct_to_guc(ct);
struct guc_ct_buffer_desc *desc;
u32 blob_size;
u32 cmds_size;
u32 resv_space;
void *blob;
u32 *cmds;
int err;
err = i915_inject_probe_error(guc_to_i915(guc), -ENXIO);
if (err)
return err;
GEM_BUG_ON(ct->vma);
blob_size = 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE + CTB_G2H_BUFFER_SIZE;
err = intel_guc_allocate_and_map_vma(guc, blob_size, &ct->vma, &blob);
if (unlikely(err)) {
CT_PROBE_ERROR(ct, "Failed to allocate %u for CTB data (%pe)\n",
blob_size, ERR_PTR(err));
return err;
}
CT_DEBUG(ct, "base=%#x size=%u\n", intel_guc_ggtt_offset(guc, ct->vma), blob_size);
/* store pointers to desc and cmds for send ctb */
desc = blob;
cmds = blob + 2 * CTB_DESC_SIZE;
cmds_size = CTB_H2G_BUFFER_SIZE;
resv_space = 0;
CT_DEBUG(ct, "%s desc %#tx cmds %#tx size %u/%u\n", "send",
ptrdiff(desc, blob), ptrdiff(cmds, blob), cmds_size,
resv_space);
guc_ct_buffer_init(&ct->ctbs.send, desc, cmds, cmds_size, resv_space);
/* store pointers to desc and cmds for recv ctb */
desc = blob + CTB_DESC_SIZE;
cmds = blob + 2 * CTB_DESC_SIZE + CTB_H2G_BUFFER_SIZE;
cmds_size = CTB_G2H_BUFFER_SIZE;
resv_space = G2H_ROOM_BUFFER_SIZE;
CT_DEBUG(ct, "%s desc %#tx cmds %#tx size %u/%u\n", "recv",
ptrdiff(desc, blob), ptrdiff(cmds, blob), cmds_size,
resv_space);
guc_ct_buffer_init(&ct->ctbs.recv, desc, cmds, cmds_size, resv_space);
return 0;
}
/**
* intel_guc_ct_fini - Fini buffer-based communication
* @ct: pointer to CT struct
*
* Deallocate memory required for buffer-based communication.
*/
void intel_guc_ct_fini(struct intel_guc_ct *ct)
{
GEM_BUG_ON(ct->enabled);
tasklet_kill(&ct->receive_tasklet);
i915_vma_unpin_and_release(&ct->vma, I915_VMA_RELEASE_MAP);
memset(ct, 0, sizeof(*ct));
}
/**
* intel_guc_ct_enable - Enable buffer based command transport.
* @ct: pointer to CT struct
*
* Return: 0 on success, a negative errno code on failure.
*/
int intel_guc_ct_enable(struct intel_guc_ct *ct)
{
struct intel_guc *guc = ct_to_guc(ct);
u32 base, desc, cmds, size;
void *blob;
int err;
GEM_BUG_ON(ct->enabled);
/* vma should be already allocated and map'ed */
GEM_BUG_ON(!ct->vma);
GEM_BUG_ON(!i915_gem_object_has_pinned_pages(ct->vma->obj));
base = intel_guc_ggtt_offset(guc, ct->vma);
/* blob should start with send descriptor */
blob = __px_vaddr(ct->vma->obj);
GEM_BUG_ON(blob != ct->ctbs.send.desc);
/* (re)initialize descriptors */
guc_ct_buffer_reset(&ct->ctbs.send);
guc_ct_buffer_reset(&ct->ctbs.recv);
/*
* Register both CT buffers starting with RECV buffer.
* Descriptors are in first half of the blob.
*/
desc = base + ptrdiff(ct->ctbs.recv.desc, blob);
cmds = base + ptrdiff(ct->ctbs.recv.cmds, blob);
size = ct->ctbs.recv.size * 4;
err = ct_register_buffer(ct, false, desc, cmds, size);
if (unlikely(err))
goto err_out;
desc = base + ptrdiff(ct->ctbs.send.desc, blob);
cmds = base + ptrdiff(ct->ctbs.send.cmds, blob);
size = ct->ctbs.send.size * 4;
err = ct_register_buffer(ct, true, desc, cmds, size);
if (unlikely(err))
goto err_out;
err = ct_control_enable(ct, true);
if (unlikely(err))
goto err_out;
ct->enabled = true;
ct->stall_time = KTIME_MAX;
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
ct->dead_ct_reported = false;
ct->dead_ct_reason = CT_DEAD_ALIVE;
#endif
return 0;
err_out:
CT_PROBE_ERROR(ct, "Failed to enable CTB (%pe)\n", ERR_PTR(err));
CT_DEAD(ct, SETUP);
return err;
}
/**
* intel_guc_ct_disable - Disable buffer based command transport.
* @ct: pointer to CT struct
*/
void intel_guc_ct_disable(struct intel_guc_ct *ct)
{
struct intel_guc *guc = ct_to_guc(ct);
GEM_BUG_ON(!ct->enabled);
ct->enabled = false;
if (intel_guc_is_fw_running(guc)) {
ct_control_enable(ct, false);
}
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
static void ct_track_lost_and_found(struct intel_guc_ct *ct, u32 fence, u32 action)
{
unsigned int lost = fence % ARRAY_SIZE(ct->requests.lost_and_found);
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
unsigned long entries[SZ_32];
unsigned int n;
n = stack_trace_save(entries, ARRAY_SIZE(entries), 1);
/* May be called under spinlock, so avoid sleeping */
ct->requests.lost_and_found[lost].stack = stack_depot_save(entries, n, GFP_NOWAIT);
#endif
ct->requests.lost_and_found[lost].fence = fence;
ct->requests.lost_and_found[lost].action = action;
}
#endif
static u32 ct_get_next_fence(struct intel_guc_ct *ct)
{
/* For now it's trivial */
return ++ct->requests.last_fence;
}
static int ct_write(struct intel_guc_ct *ct,
const u32 *action,
u32 len /* in dwords */,
u32 fence, u32 flags)
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs.send;
struct guc_ct_buffer_desc *desc = ctb->desc;
u32 tail = ctb->tail;
u32 size = ctb->size;
u32 header;
u32 hxg;
u32 type;
u32 *cmds = ctb->cmds;
unsigned int i;
if (unlikely(desc->status))
goto corrupted;
GEM_BUG_ON(tail > size);
#ifdef CONFIG_DRM_I915_DEBUG_GUC
if (unlikely(tail != READ_ONCE(desc->tail))) {
CT_ERROR(ct, "Tail was modified %u != %u\n",
desc->tail, tail);
desc->status |= GUC_CTB_STATUS_MISMATCH;
goto corrupted;
}
if (unlikely(READ_ONCE(desc->head) >= size)) {
CT_ERROR(ct, "Invalid head offset %u >= %u)\n",
desc->head, size);
desc->status |= GUC_CTB_STATUS_OVERFLOW;
goto corrupted;
}
#endif
/*
* dw0: CT header (including fence)
* dw1: HXG header (including action code)
* dw2+: action data
*/
header = FIELD_PREP(GUC_CTB_MSG_0_FORMAT, GUC_CTB_FORMAT_HXG) |
FIELD_PREP(GUC_CTB_MSG_0_NUM_DWORDS, len) |
FIELD_PREP(GUC_CTB_MSG_0_FENCE, fence);
type = (flags & INTEL_GUC_CT_SEND_NB) ? GUC_HXG_TYPE_FAST_REQUEST :
GUC_HXG_TYPE_REQUEST;
hxg = FIELD_PREP(GUC_HXG_MSG_0_TYPE, type) |
FIELD_PREP(GUC_HXG_REQUEST_MSG_0_ACTION |
GUC_HXG_REQUEST_MSG_0_DATA0, action[0]);
CT_DEBUG(ct, "writing (tail %u) %*ph %*ph %*ph\n",
tail, 4, &header, 4, &hxg, 4 * (len - 1), &action[1]);
cmds[tail] = header;
tail = (tail + 1) % size;
cmds[tail] = hxg;
tail = (tail + 1) % size;
for (i = 1; i < len; i++) {
cmds[tail] = action[i];
tail = (tail + 1) % size;
}
GEM_BUG_ON(tail > size);
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
ct_track_lost_and_found(ct, fence,
FIELD_GET(GUC_HXG_EVENT_MSG_0_ACTION, action[0]));
#endif
/*
* make sure H2G buffer update and LRC tail update (if this triggering a
* submission) are visible before updating the descriptor tail
*/
intel_guc_write_barrier(ct_to_guc(ct));
/* update local copies */
ctb->tail = tail;
GEM_BUG_ON(atomic_read(&ctb->space) < len + GUC_CTB_HDR_LEN);
atomic_sub(len + GUC_CTB_HDR_LEN, &ctb->space);
/* now update descriptor */
WRITE_ONCE(desc->tail, tail);
return 0;
corrupted:
CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n",
desc->head, desc->tail, desc->status);
CT_DEAD(ct, WRITE);
ctb->broken = true;
return -EPIPE;
}
/**
* wait_for_ct_request_update - Wait for CT request state update.
* @ct: pointer to CT
* @req: pointer to pending request
* @status: placeholder for status
*
* For each sent request, GuC shall send back CT response message.
* Our message handler will update status of tracked request once
* response message with given fence is received. Wait here and
* check for valid response status value.
*
* Return:
* * 0 response received (status is valid)
* * -ETIMEDOUT no response within hardcoded timeout
*/
static int wait_for_ct_request_update(struct intel_guc_ct *ct, struct ct_request *req, u32 *status)
{
int err;
bool ct_enabled;
/*
* Fast commands should complete in less than 10us, so sample quickly
* up to that length of time, then switch to a slower sleep-wait loop.
* No GuC command should ever take longer than 10ms but many GuC
* commands can be inflight at time, so use a 1s timeout on the slower
* sleep-wait loop.
*/
#define GUC_CTB_RESPONSE_TIMEOUT_SHORT_MS 10
#define GUC_CTB_RESPONSE_TIMEOUT_LONG_MS 1000
#define done \
(!(ct_enabled = intel_guc_ct_enabled(ct)) || \
FIELD_GET(GUC_HXG_MSG_0_ORIGIN, READ_ONCE(req->status)) == \
GUC_HXG_ORIGIN_GUC)
err = wait_for_us(done, GUC_CTB_RESPONSE_TIMEOUT_SHORT_MS);
if (err)
err = wait_for(done, GUC_CTB_RESPONSE_TIMEOUT_LONG_MS);
#undef done
if (!ct_enabled)
err = -ENODEV;
*status = req->status;
return err;
}
#define GUC_CTB_TIMEOUT_MS 1500
static inline bool ct_deadlocked(struct intel_guc_ct *ct)
{
long timeout = GUC_CTB_TIMEOUT_MS;
bool ret = ktime_ms_delta(ktime_get(), ct->stall_time) > timeout;
if (unlikely(ret)) {
struct guc_ct_buffer_desc *send = ct->ctbs.send.desc;
struct guc_ct_buffer_desc *recv = ct->ctbs.send.desc;
CT_ERROR(ct, "Communication stalled for %lld ms, desc status=%#x,%#x\n",
ktime_ms_delta(ktime_get(), ct->stall_time),
send->status, recv->status);
CT_ERROR(ct, "H2G Space: %u (Bytes)\n",
atomic_read(&ct->ctbs.send.space) * 4);
CT_ERROR(ct, "Head: %u (Dwords)\n", ct->ctbs.send.desc->head);
CT_ERROR(ct, "Tail: %u (Dwords)\n", ct->ctbs.send.desc->tail);
CT_ERROR(ct, "G2H Space: %u (Bytes)\n",
atomic_read(&ct->ctbs.recv.space) * 4);
CT_ERROR(ct, "Head: %u\n (Dwords)", ct->ctbs.recv.desc->head);
CT_ERROR(ct, "Tail: %u\n (Dwords)", ct->ctbs.recv.desc->tail);
CT_DEAD(ct, DEADLOCK);
ct->ctbs.send.broken = true;
}
return ret;
}
static inline bool g2h_has_room(struct intel_guc_ct *ct, u32 g2h_len_dw)
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs.recv;
/*
* We leave a certain amount of space in the G2H CTB buffer for
* unexpected G2H CTBs (e.g. logging, engine hang, etc...)
*/
return !g2h_len_dw || atomic_read(&ctb->space) >= g2h_len_dw;
}
static inline void g2h_reserve_space(struct intel_guc_ct *ct, u32 g2h_len_dw)
{
lockdep_assert_held(&ct->ctbs.send.lock);
GEM_BUG_ON(!g2h_has_room(ct, g2h_len_dw));
if (g2h_len_dw)
atomic_sub(g2h_len_dw, &ct->ctbs.recv.space);
}
static inline void g2h_release_space(struct intel_guc_ct *ct, u32 g2h_len_dw)
{
atomic_add(g2h_len_dw, &ct->ctbs.recv.space);
}
static inline bool h2g_has_room(struct intel_guc_ct *ct, u32 len_dw)
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs.send;
struct guc_ct_buffer_desc *desc = ctb->desc;
u32 head;
u32 space;
if (atomic_read(&ctb->space) >= len_dw)
return true;
head = READ_ONCE(desc->head);
if (unlikely(head > ctb->size)) {
CT_ERROR(ct, "Invalid head offset %u >= %u)\n",
head, ctb->size);
desc->status |= GUC_CTB_STATUS_OVERFLOW;
ctb->broken = true;
CT_DEAD(ct, H2G_HAS_ROOM);
return false;
}
space = CIRC_SPACE(ctb->tail, head, ctb->size);
atomic_set(&ctb->space, space);
return space >= len_dw;
}
static int has_room_nb(struct intel_guc_ct *ct, u32 h2g_dw, u32 g2h_dw)
{
bool h2g = h2g_has_room(ct, h2g_dw);
bool g2h = g2h_has_room(ct, g2h_dw);
lockdep_assert_held(&ct->ctbs.send.lock);
if (unlikely(!h2g || !g2h)) {
if (ct->stall_time == KTIME_MAX)
ct->stall_time = ktime_get();
/* Be paranoid and kick G2H tasklet to free credits */
if (!g2h)
tasklet_hi_schedule(&ct->receive_tasklet);
if (unlikely(ct_deadlocked(ct)))
return -EPIPE;
else
return -EBUSY;
}
ct->stall_time = KTIME_MAX;
return 0;
}
#define G2H_LEN_DW(f) ({ \
typeof(f) f_ = (f); \
FIELD_GET(INTEL_GUC_CT_SEND_G2H_DW_MASK, f_) ? \
FIELD_GET(INTEL_GUC_CT_SEND_G2H_DW_MASK, f_) + \
GUC_CTB_HXG_MSG_MIN_LEN : 0; \
})
static int ct_send_nb(struct intel_guc_ct *ct,
const u32 *action,
u32 len,
u32 flags)
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs.send;
unsigned long spin_flags;
u32 g2h_len_dw = G2H_LEN_DW(flags);
u32 fence;
int ret;
spin_lock_irqsave(&ctb->lock, spin_flags);
ret = has_room_nb(ct, len + GUC_CTB_HDR_LEN, g2h_len_dw);
if (unlikely(ret))
goto out;
fence = ct_get_next_fence(ct);
ret = ct_write(ct, action, len, fence, flags);
if (unlikely(ret))
goto out;
g2h_reserve_space(ct, g2h_len_dw);
intel_guc_notify(ct_to_guc(ct));
out:
spin_unlock_irqrestore(&ctb->lock, spin_flags);
return ret;
}
static int ct_send(struct intel_guc_ct *ct,
const u32 *action,
u32 len,
u32 *response_buf,
u32 response_buf_size,
u32 *status)
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs.send;
struct ct_request request;
unsigned long flags;
unsigned int sleep_period_ms = 1;
bool send_again;
u32 fence;
int err;
GEM_BUG_ON(!ct->enabled);
GEM_BUG_ON(!len);
GEM_BUG_ON(len > GUC_CTB_HXG_MSG_MAX_LEN - GUC_CTB_HDR_LEN);
GEM_BUG_ON(!response_buf && response_buf_size);
might_sleep();
resend:
send_again = false;
/*
* We use a lazy spin wait loop here as we believe that if the CT
* buffers are sized correctly the flow control condition should be
* rare. Reserving the maximum size in the G2H credits as we don't know
* how big the response is going to be.
*/
retry:
spin_lock_irqsave(&ctb->lock, flags);
if (unlikely(!h2g_has_room(ct, len + GUC_CTB_HDR_LEN) ||
!g2h_has_room(ct, GUC_CTB_HXG_MSG_MAX_LEN))) {
if (ct->stall_time == KTIME_MAX)
ct->stall_time = ktime_get();
spin_unlock_irqrestore(&ctb->lock, flags);
if (unlikely(ct_deadlocked(ct)))
return -EPIPE;
if (msleep_interruptible(sleep_period_ms))
return -EINTR;
sleep_period_ms = sleep_period_ms << 1;
goto retry;
}
ct->stall_time = KTIME_MAX;
fence = ct_get_next_fence(ct);
request.fence = fence;
request.status = 0;
request.response_len = response_buf_size;
request.response_buf = response_buf;
spin_lock(&ct->requests.lock);
list_add_tail(&request.link, &ct->requests.pending);
spin_unlock(&ct->requests.lock);
err = ct_write(ct, action, len, fence, 0);
g2h_reserve_space(ct, GUC_CTB_HXG_MSG_MAX_LEN);
spin_unlock_irqrestore(&ctb->lock, flags);
if (unlikely(err))
goto unlink;
intel_guc_notify(ct_to_guc(ct));
err = wait_for_ct_request_update(ct, &request, status);
g2h_release_space(ct, GUC_CTB_HXG_MSG_MAX_LEN);
if (unlikely(err)) {
if (err == -ENODEV)
/* wait_for_ct_request_update returns -ENODEV on reset/suspend in progress.
* In this case, output is debug rather than error info
*/
CT_DEBUG(ct, "Request %#x (fence %u) cancelled as CTB is disabled\n",
action[0], request.fence);
else
CT_ERROR(ct, "No response for request %#x (fence %u)\n",
action[0], request.fence);
goto unlink;
}
if (FIELD_GET(GUC_HXG_MSG_0_TYPE, *status) == GUC_HXG_TYPE_NO_RESPONSE_RETRY) {
CT_DEBUG(ct, "retrying request %#x (%u)\n", *action,
FIELD_GET(GUC_HXG_RETRY_MSG_0_REASON, *status));
send_again = true;
goto unlink;
}
if (FIELD_GET(GUC_HXG_MSG_0_TYPE, *status) != GUC_HXG_TYPE_RESPONSE_SUCCESS) {
err = -EIO;
goto unlink;
}
if (response_buf) {
/* There shall be no data in the status */
WARN_ON(FIELD_GET(GUC_HXG_RESPONSE_MSG_0_DATA0, request.status));
/* Return actual response len */
err = request.response_len;
} else {
/* There shall be no response payload */
WARN_ON(request.response_len);
/* Return data decoded from the status dword */
err = FIELD_GET(GUC_HXG_RESPONSE_MSG_0_DATA0, *status);
}
unlink:
spin_lock_irqsave(&ct->requests.lock, flags);
list_del(&request.link);
spin_unlock_irqrestore(&ct->requests.lock, flags);
if (unlikely(send_again))
goto resend;
return err;
}
/*
* Command Transport (CT) buffer based GuC send function.
*/
int intel_guc_ct_send(struct intel_guc_ct *ct, const u32 *action, u32 len,
u32 *response_buf, u32 response_buf_size, u32 flags)
{
u32 status = ~0; /* undefined */
int ret;
if (unlikely(!ct->enabled)) {
struct intel_guc *guc = ct_to_guc(ct);
struct intel_uc *uc = container_of(guc, struct intel_uc, guc);
WARN(!uc->reset_in_progress, "Unexpected send: action=%#x\n", *action);
return -ENODEV;
}
if (unlikely(ct->ctbs.send.broken))
return -EPIPE;
if (flags & INTEL_GUC_CT_SEND_NB)
return ct_send_nb(ct, action, len, flags);
ret = ct_send(ct, action, len, response_buf, response_buf_size, &status);
if (unlikely(ret < 0)) {
if (ret != -ENODEV)
CT_ERROR(ct, "Sending action %#x failed (%pe) status=%#X\n",
action[0], ERR_PTR(ret), status);
} else if (unlikely(ret)) {
CT_DEBUG(ct, "send action %#x returned %d (%#x)\n",
action[0], ret, ret);
}
return ret;
}
static struct ct_incoming_msg *ct_alloc_msg(u32 num_dwords)
{
struct ct_incoming_msg *msg;
msg = kmalloc(struct_size(msg, msg, num_dwords), GFP_ATOMIC);
if (msg)
msg->size = num_dwords;
return msg;
}
static void ct_free_msg(struct ct_incoming_msg *msg)
{
kfree(msg);
}
/*
* Return: number available remaining dwords to read (0 if empty)
* or a negative error code on failure
*/
static int ct_read(struct intel_guc_ct *ct, struct ct_incoming_msg **msg)
{
struct intel_guc_ct_buffer *ctb = &ct->ctbs.recv;
struct guc_ct_buffer_desc *desc = ctb->desc;
u32 head = ctb->head;
u32 tail = READ_ONCE(desc->tail);
u32 size = ctb->size;
u32 *cmds = ctb->cmds;
s32 available;
unsigned int len;
unsigned int i;
u32 header;
if (unlikely(ctb->broken))
return -EPIPE;
if (unlikely(desc->status)) {
u32 status = desc->status;
if (status & GUC_CTB_STATUS_UNUSED) {
/*
* Potentially valid if a CLIENT_RESET request resulted in
* contexts/engines being reset. But should never happen as
* no contexts should be active when CLIENT_RESET is sent.
*/
CT_ERROR(ct, "Unexpected G2H after GuC has stopped!\n");
status &= ~GUC_CTB_STATUS_UNUSED;
}
if (status)
goto corrupted;
}
GEM_BUG_ON(head > size);
#ifdef CONFIG_DRM_I915_DEBUG_GUC
if (unlikely(head != READ_ONCE(desc->head))) {
CT_ERROR(ct, "Head was modified %u != %u\n",
desc->head, head);
desc->status |= GUC_CTB_STATUS_MISMATCH;
goto corrupted;
}
#endif
if (unlikely(tail >= size)) {
CT_ERROR(ct, "Invalid tail offset %u >= %u)\n",
tail, size);
desc->status |= GUC_CTB_STATUS_OVERFLOW;
goto corrupted;
}
/* tail == head condition indicates empty */
available = tail - head;
if (unlikely(available == 0)) {
*msg = NULL;
return 0;
}
/* beware of buffer wrap case */
if (unlikely(available < 0))
available += size;
CT_DEBUG(ct, "available %d (%u:%u:%u)\n", available, head, tail, size);
GEM_BUG_ON(available < 0);
header = cmds[head];
head = (head + 1) % size;
/* message len with header */
len = FIELD_GET(GUC_CTB_MSG_0_NUM_DWORDS, header) + GUC_CTB_MSG_MIN_LEN;
if (unlikely(len > (u32)available)) {
CT_ERROR(ct, "Incomplete message %*ph %*ph %*ph\n",
4, &header,
4 * (head + available - 1 > size ?
size - head : available - 1), &cmds[head],
4 * (head + available - 1 > size ?
available - 1 - size + head : 0), &cmds[0]);
desc->status |= GUC_CTB_STATUS_UNDERFLOW;
goto corrupted;
}
*msg = ct_alloc_msg(len);
if (!*msg) {
CT_ERROR(ct, "No memory for message %*ph %*ph %*ph\n",
4, &header,
4 * (head + available - 1 > size ?
size - head : available - 1), &cmds[head],
4 * (head + available - 1 > size ?
available - 1 - size + head : 0), &cmds[0]);
return available;
}
(*msg)->msg[0] = header;
for (i = 1; i < len; i++) {
(*msg)->msg[i] = cmds[head];
head = (head + 1) % size;
}
CT_DEBUG(ct, "received %*ph\n", 4 * len, (*msg)->msg);
/* update local copies */
ctb->head = head;
/* now update descriptor */
WRITE_ONCE(desc->head, head);
intel_guc_write_barrier(ct_to_guc(ct));
return available - len;
corrupted:
CT_ERROR(ct, "Corrupted descriptor head=%u tail=%u status=%#x\n",
desc->head, desc->tail, desc->status);
ctb->broken = true;
CT_DEAD(ct, READ);
return -EPIPE;
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
static bool ct_check_lost_and_found(struct intel_guc_ct *ct, u32 fence)
{
unsigned int n;
char *buf = NULL;
bool found = false;
lockdep_assert_held(&ct->requests.lock);
for (n = 0; n < ARRAY_SIZE(ct->requests.lost_and_found); n++) {
if (ct->requests.lost_and_found[n].fence != fence)
continue;
found = true;
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
buf = kmalloc(SZ_4K, GFP_NOWAIT);
if (buf && stack_depot_snprint(ct->requests.lost_and_found[n].stack,
buf, SZ_4K, 0)) {
CT_ERROR(ct, "Fence %u was used by action %#04x sent at\n%s",
fence, ct->requests.lost_and_found[n].action, buf);
break;
}
#endif
CT_ERROR(ct, "Fence %u was used by action %#04x\n",
fence, ct->requests.lost_and_found[n].action);
break;
}
kfree(buf);
return found;
}
#else
static bool ct_check_lost_and_found(struct intel_guc_ct *ct, u32 fence)
{
return false;
}
#endif
static int ct_handle_response(struct intel_guc_ct *ct, struct ct_incoming_msg *response)
{
u32 len = FIELD_GET(GUC_CTB_MSG_0_NUM_DWORDS, response->msg[0]);
u32 fence = FIELD_GET(GUC_CTB_MSG_0_FENCE, response->msg[0]);
const u32 *hxg = &response->msg[GUC_CTB_MSG_MIN_LEN];
const u32 *data = &hxg[GUC_HXG_MSG_MIN_LEN];
u32 datalen = len - GUC_HXG_MSG_MIN_LEN;
struct ct_request *req;
unsigned long flags;
bool found = false;
int err = 0;
GEM_BUG_ON(len < GUC_HXG_MSG_MIN_LEN);
GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_ORIGIN, hxg[0]) != GUC_HXG_ORIGIN_GUC);
GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_TYPE, hxg[0]) != GUC_HXG_TYPE_RESPONSE_SUCCESS &&
FIELD_GET(GUC_HXG_MSG_0_TYPE, hxg[0]) != GUC_HXG_TYPE_NO_RESPONSE_RETRY &&
FIELD_GET(GUC_HXG_MSG_0_TYPE, hxg[0]) != GUC_HXG_TYPE_RESPONSE_FAILURE);
CT_DEBUG(ct, "response fence %u status %#x\n", fence, hxg[0]);
spin_lock_irqsave(&ct->requests.lock, flags);
list_for_each_entry(req, &ct->requests.pending, link) {
if (unlikely(fence != req->fence)) {
CT_DEBUG(ct, "request %u awaits response\n",
req->fence);
continue;
}
if (unlikely(datalen > req->response_len)) {
CT_ERROR(ct, "Response %u too long (datalen %u > %u)\n",
req->fence, datalen, req->response_len);
datalen = min(datalen, req->response_len);
err = -EMSGSIZE;
}
if (datalen)
memcpy(req->response_buf, data, 4 * datalen);
req->response_len = datalen;
WRITE_ONCE(req->status, hxg[0]);
found = true;
break;
}
#ifdef CONFIG_DRM_I915_SELFTEST
if (!found && ct_to_guc(ct)->fast_response_selftest) {
CT_DEBUG(ct, "Assuming unsolicited response due to FAST_REQUEST selftest\n");
ct_to_guc(ct)->fast_response_selftest++;
found = true;
}
#endif
if (!found) {
CT_ERROR(ct, "Unsolicited response message: len %u, data %#x (fence %u, last %u)\n",
len, hxg[0], fence, ct->requests.last_fence);
if (!ct_check_lost_and_found(ct, fence)) {
list_for_each_entry(req, &ct->requests.pending, link)
CT_ERROR(ct, "request %u awaits response\n",
req->fence);
}
err = -ENOKEY;
}
spin_unlock_irqrestore(&ct->requests.lock, flags);
if (unlikely(err))
return err;
ct_free_msg(response);
return 0;
}
static int ct_process_request(struct intel_guc_ct *ct, struct ct_incoming_msg *request)
{
struct intel_guc *guc = ct_to_guc(ct);
const u32 *hxg;
const u32 *payload;
u32 hxg_len, action, len;
int ret;
hxg = &request->msg[GUC_CTB_MSG_MIN_LEN];
hxg_len = request->size - GUC_CTB_MSG_MIN_LEN;
payload = &hxg[GUC_HXG_MSG_MIN_LEN];
action = FIELD_GET(GUC_HXG_EVENT_MSG_0_ACTION, hxg[0]);
len = hxg_len - GUC_HXG_MSG_MIN_LEN;
CT_DEBUG(ct, "request %x %*ph\n", action, 4 * len, payload);
switch (action) {
case INTEL_GUC_ACTION_DEFAULT:
ret = intel_guc_to_host_process_recv_msg(guc, payload, len);
break;
case INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE:
ret = intel_guc_deregister_done_process_msg(guc, payload,
len);
break;
case INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_DONE:
ret = intel_guc_sched_done_process_msg(guc, payload, len);
break;
case INTEL_GUC_ACTION_CONTEXT_RESET_NOTIFICATION:
ret = intel_guc_context_reset_process_msg(guc, payload, len);
break;
case INTEL_GUC_ACTION_STATE_CAPTURE_NOTIFICATION:
ret = intel_guc_error_capture_process_msg(guc, payload, len);
if (unlikely(ret))
CT_ERROR(ct, "error capture notification failed %x %*ph\n",
action, 4 * len, payload);
break;
case INTEL_GUC_ACTION_ENGINE_FAILURE_NOTIFICATION:
ret = intel_guc_engine_failure_process_msg(guc, payload, len);
break;
case INTEL_GUC_ACTION_NOTIFY_FLUSH_LOG_BUFFER_TO_FILE:
intel_guc_log_handle_flush_event(&guc->log);
ret = 0;
break;
case INTEL_GUC_ACTION_NOTIFY_CRASH_DUMP_POSTED:
case INTEL_GUC_ACTION_NOTIFY_EXCEPTION:
ret = intel_guc_crash_process_msg(guc, action);
break;
case INTEL_GUC_ACTION_TLB_INVALIDATION_DONE:
ret = intel_guc_tlb_invalidation_done(guc, payload, len);
break;
default:
ret = -EOPNOTSUPP;
break;
}
if (unlikely(ret)) {
CT_ERROR(ct, "Failed to process request %04x (%pe)\n",
action, ERR_PTR(ret));
return ret;
}
ct_free_msg(request);
return 0;
}
static bool ct_process_incoming_requests(struct intel_guc_ct *ct)
{
unsigned long flags;
struct ct_incoming_msg *request;
bool done;
int err;
spin_lock_irqsave(&ct->requests.lock, flags);
request = list_first_entry_or_null(&ct->requests.incoming,
struct ct_incoming_msg, link);
if (request)
list_del(&request->link);
done = !!list_empty(&ct->requests.incoming);
spin_unlock_irqrestore(&ct->requests.lock, flags);
if (!request)
return true;
err = ct_process_request(ct, request);
if (unlikely(err)) {
CT_ERROR(ct, "Failed to process CT message (%pe) %*ph\n",
ERR_PTR(err), 4 * request->size, request->msg);
CT_DEAD(ct, PROCESS_FAILED);
ct_free_msg(request);
}
return done;
}
static void ct_incoming_request_worker_func(struct work_struct *w)
{
struct intel_guc_ct *ct =
container_of(w, struct intel_guc_ct, requests.worker);
bool done;
do {
done = ct_process_incoming_requests(ct);
} while (!done);
}
static int ct_handle_event(struct intel_guc_ct *ct, struct ct_incoming_msg *request)
{
const u32 *hxg = &request->msg[GUC_CTB_MSG_MIN_LEN];
u32 action = FIELD_GET(GUC_HXG_EVENT_MSG_0_ACTION, hxg[0]);
unsigned long flags;
GEM_BUG_ON(FIELD_GET(GUC_HXG_MSG_0_TYPE, hxg[0]) != GUC_HXG_TYPE_EVENT);
/*
* Adjusting the space must be done in IRQ or deadlock can occur as the
* CTB processing in the below workqueue can send CTBs which creates a
* circular dependency if the space was returned there.
*/
switch (action) {
case INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_DONE:
case INTEL_GUC_ACTION_DEREGISTER_CONTEXT_DONE:
case INTEL_GUC_ACTION_TLB_INVALIDATION_DONE:
g2h_release_space(ct, request->size);
}
/*
* TLB invalidation responses must be handled immediately as processing
* of other G2H notifications may be blocked by an invalidation request.
*/
if (action == INTEL_GUC_ACTION_TLB_INVALIDATION_DONE)
return ct_process_request(ct, request);
spin_lock_irqsave(&ct->requests.lock, flags);
list_add_tail(&request->link, &ct->requests.incoming);
spin_unlock_irqrestore(&ct->requests.lock, flags);
queue_work(system_unbound_wq, &ct->requests.worker);
return 0;
}
static int ct_handle_hxg(struct intel_guc_ct *ct, struct ct_incoming_msg *msg)
{
u32 origin, type;
u32 *hxg;
int err;
if (unlikely(msg->size < GUC_CTB_HXG_MSG_MIN_LEN))
return -EBADMSG;
hxg = &msg->msg[GUC_CTB_MSG_MIN_LEN];
origin = FIELD_GET(GUC_HXG_MSG_0_ORIGIN, hxg[0]);
if (unlikely(origin != GUC_HXG_ORIGIN_GUC)) {
err = -EPROTO;
goto failed;
}
type = FIELD_GET(GUC_HXG_MSG_0_TYPE, hxg[0]);
switch (type) {
case GUC_HXG_TYPE_EVENT:
err = ct_handle_event(ct, msg);
break;
case GUC_HXG_TYPE_RESPONSE_SUCCESS:
case GUC_HXG_TYPE_RESPONSE_FAILURE:
case GUC_HXG_TYPE_NO_RESPONSE_RETRY:
err = ct_handle_response(ct, msg);
break;
default:
err = -EOPNOTSUPP;
}
if (unlikely(err)) {
failed:
CT_ERROR(ct, "Failed to handle HXG message (%pe) %*ph\n",
ERR_PTR(err), 4 * GUC_HXG_MSG_MIN_LEN, hxg);
}
return err;
}
static void ct_handle_msg(struct intel_guc_ct *ct, struct ct_incoming_msg *msg)
{
u32 format = FIELD_GET(GUC_CTB_MSG_0_FORMAT, msg->msg[0]);
int err;
if (format == GUC_CTB_FORMAT_HXG)
err = ct_handle_hxg(ct, msg);
else
err = -EOPNOTSUPP;
if (unlikely(err)) {
CT_ERROR(ct, "Failed to process CT message (%pe) %*ph\n",
ERR_PTR(err), 4 * msg->size, msg->msg);
ct_free_msg(msg);
}
}
/*
* Return: number available remaining dwords to read (0 if empty)
* or a negative error code on failure
*/
static int ct_receive(struct intel_guc_ct *ct)
{
struct ct_incoming_msg *msg = NULL;
unsigned long flags;
int ret;
spin_lock_irqsave(&ct->ctbs.recv.lock, flags);
ret = ct_read(ct, &msg);
spin_unlock_irqrestore(&ct->ctbs.recv.lock, flags);
if (ret < 0)
return ret;
if (msg)
ct_handle_msg(ct, msg);
return ret;
}
static void ct_try_receive_message(struct intel_guc_ct *ct)
{
int ret;
if (GEM_WARN_ON(!ct->enabled))
return;
ret = ct_receive(ct);
if (ret > 0)
tasklet_hi_schedule(&ct->receive_tasklet);
}
static void ct_receive_tasklet_func(struct tasklet_struct *t)
{
struct intel_guc_ct *ct = from_tasklet(ct, t, receive_tasklet);
ct_try_receive_message(ct);
}
/*
* When we're communicating with the GuC over CT, GuC uses events
* to notify us about new messages being posted on the RECV buffer.
*/
void intel_guc_ct_event_handler(struct intel_guc_ct *ct)
{
if (unlikely(!ct->enabled)) {
WARN(1, "Unexpected GuC event received while CT disabled!\n");
return;
}
ct_try_receive_message(ct);
}
void intel_guc_ct_print_info(struct intel_guc_ct *ct,
struct drm_printer *p)
{
drm_printf(p, "CT %s\n", str_enabled_disabled(ct->enabled));
if (!ct->enabled)
return;
drm_printf(p, "H2G Space: %u\n",
atomic_read(&ct->ctbs.send.space) * 4);
drm_printf(p, "Head: %u\n",
ct->ctbs.send.desc->head);
drm_printf(p, "Tail: %u\n",
ct->ctbs.send.desc->tail);
drm_printf(p, "G2H Space: %u\n",
atomic_read(&ct->ctbs.recv.space) * 4);
drm_printf(p, "Head: %u\n",
ct->ctbs.recv.desc->head);
drm_printf(p, "Tail: %u\n",
ct->ctbs.recv.desc->tail);
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GUC)
static void ct_dead_ct_worker_func(struct work_struct *w)
{
struct intel_guc_ct *ct = container_of(w, struct intel_guc_ct, dead_ct_worker);
struct intel_guc *guc = ct_to_guc(ct);
if (ct->dead_ct_reported)
return;
ct->dead_ct_reported = true;
guc_info(guc, "CTB is dead - reason=0x%X\n", ct->dead_ct_reason);
intel_klog_error_capture(guc_to_gt(guc), (intel_engine_mask_t)~0U);
}
#endif
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