linux/drivers/gpu/drm/i915/i915_gpu_error.c

1554 lines
41 KiB
C

/*
* Copyright (c) 2008 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
* Keith Packard <keithp@keithp.com>
* Mika Kuoppala <mika.kuoppala@intel.com>
*
*/
#include <generated/utsrelease.h>
#include "i915_drv.h"
static const char *engine_str(int engine)
{
switch (engine) {
case RCS: return "render";
case VCS: return "bsd";
case BCS: return "blt";
case VECS: return "vebox";
case VCS2: return "bsd2";
default: return "";
}
}
static const char *tiling_flag(int tiling)
{
switch (tiling) {
default:
case I915_TILING_NONE: return "";
case I915_TILING_X: return " X";
case I915_TILING_Y: return " Y";
}
}
static const char *dirty_flag(int dirty)
{
return dirty ? " dirty" : "";
}
static const char *purgeable_flag(int purgeable)
{
return purgeable ? " purgeable" : "";
}
static bool __i915_error_ok(struct drm_i915_error_state_buf *e)
{
if (!e->err && WARN(e->bytes > (e->size - 1), "overflow")) {
e->err = -ENOSPC;
return false;
}
if (e->bytes == e->size - 1 || e->err)
return false;
return true;
}
static bool __i915_error_seek(struct drm_i915_error_state_buf *e,
unsigned len)
{
if (e->pos + len <= e->start) {
e->pos += len;
return false;
}
/* First vsnprintf needs to fit in its entirety for memmove */
if (len >= e->size) {
e->err = -EIO;
return false;
}
return true;
}
static void __i915_error_advance(struct drm_i915_error_state_buf *e,
unsigned len)
{
/* If this is first printf in this window, adjust it so that
* start position matches start of the buffer
*/
if (e->pos < e->start) {
const size_t off = e->start - e->pos;
/* Should not happen but be paranoid */
if (off > len || e->bytes) {
e->err = -EIO;
return;
}
memmove(e->buf, e->buf + off, len - off);
e->bytes = len - off;
e->pos = e->start;
return;
}
e->bytes += len;
e->pos += len;
}
static void i915_error_vprintf(struct drm_i915_error_state_buf *e,
const char *f, va_list args)
{
unsigned len;
if (!__i915_error_ok(e))
return;
/* Seek the first printf which is hits start position */
if (e->pos < e->start) {
va_list tmp;
va_copy(tmp, args);
len = vsnprintf(NULL, 0, f, tmp);
va_end(tmp);
if (!__i915_error_seek(e, len))
return;
}
len = vsnprintf(e->buf + e->bytes, e->size - e->bytes, f, args);
if (len >= e->size - e->bytes)
len = e->size - e->bytes - 1;
__i915_error_advance(e, len);
}
static void i915_error_puts(struct drm_i915_error_state_buf *e,
const char *str)
{
unsigned len;
if (!__i915_error_ok(e))
return;
len = strlen(str);
/* Seek the first printf which is hits start position */
if (e->pos < e->start) {
if (!__i915_error_seek(e, len))
return;
}
if (len >= e->size - e->bytes)
len = e->size - e->bytes - 1;
memcpy(e->buf + e->bytes, str, len);
__i915_error_advance(e, len);
}
#define err_printf(e, ...) i915_error_printf(e, __VA_ARGS__)
#define err_puts(e, s) i915_error_puts(e, s)
static void print_error_buffers(struct drm_i915_error_state_buf *m,
const char *name,
struct drm_i915_error_buffer *err,
int count)
{
int i;
err_printf(m, "%s [%d]:\n", name, count);
while (count--) {
err_printf(m, " %08x_%08x %8u %02x %02x [ ",
upper_32_bits(err->gtt_offset),
lower_32_bits(err->gtt_offset),
err->size,
err->read_domains,
err->write_domain);
for (i = 0; i < I915_NUM_ENGINES; i++)
err_printf(m, "%02x ", err->rseqno[i]);
err_printf(m, "] %02x", err->wseqno);
err_puts(m, tiling_flag(err->tiling));
err_puts(m, dirty_flag(err->dirty));
err_puts(m, purgeable_flag(err->purgeable));
err_puts(m, err->userptr ? " userptr" : "");
err_puts(m, err->engine != -1 ? " " : "");
err_puts(m, engine_str(err->engine));
err_puts(m, i915_cache_level_str(m->i915, err->cache_level));
if (err->name)
err_printf(m, " (name: %d)", err->name);
if (err->fence_reg != I915_FENCE_REG_NONE)
err_printf(m, " (fence: %d)", err->fence_reg);
err_puts(m, "\n");
err++;
}
}
static const char *hangcheck_action_to_str(enum intel_engine_hangcheck_action a)
{
switch (a) {
case HANGCHECK_IDLE:
return "idle";
case HANGCHECK_WAIT:
return "wait";
case HANGCHECK_ACTIVE:
return "active";
case HANGCHECK_KICK:
return "kick";
case HANGCHECK_HUNG:
return "hung";
}
return "unknown";
}
static void error_print_instdone(struct drm_i915_error_state_buf *m,
struct drm_i915_error_engine *ee)
{
int slice;
int subslice;
err_printf(m, " INSTDONE: 0x%08x\n",
ee->instdone.instdone);
if (ee->engine_id != RCS || INTEL_GEN(m->i915) <= 3)
return;
err_printf(m, " SC_INSTDONE: 0x%08x\n",
ee->instdone.slice_common);
if (INTEL_GEN(m->i915) <= 6)
return;
for_each_instdone_slice_subslice(m->i915, slice, subslice)
err_printf(m, " SAMPLER_INSTDONE[%d][%d]: 0x%08x\n",
slice, subslice,
ee->instdone.sampler[slice][subslice]);
for_each_instdone_slice_subslice(m->i915, slice, subslice)
err_printf(m, " ROW_INSTDONE[%d][%d]: 0x%08x\n",
slice, subslice,
ee->instdone.row[slice][subslice]);
}
static void error_print_engine(struct drm_i915_error_state_buf *m,
struct drm_i915_error_engine *ee)
{
err_printf(m, "%s command stream:\n", engine_str(ee->engine_id));
err_printf(m, " START: 0x%08x\n", ee->start);
err_printf(m, " HEAD: 0x%08x\n [0x%08x]", ee->head, ee->rq_head);
err_printf(m, " TAIL: 0x%08x [0x%08x, 0x%08x]\n",
ee->tail, ee->rq_post, ee->rq_tail);
err_printf(m, " CTL: 0x%08x\n", ee->ctl);
err_printf(m, " MODE: 0x%08x\n", ee->mode);
err_printf(m, " HWS: 0x%08x\n", ee->hws);
err_printf(m, " ACTHD: 0x%08x %08x\n",
(u32)(ee->acthd>>32), (u32)ee->acthd);
err_printf(m, " IPEIR: 0x%08x\n", ee->ipeir);
err_printf(m, " IPEHR: 0x%08x\n", ee->ipehr);
error_print_instdone(m, ee);
if (ee->batchbuffer) {
u64 start = ee->batchbuffer->gtt_offset;
u64 end = start + ee->batchbuffer->gtt_size;
err_printf(m, " batch: [0x%08x_%08x, 0x%08x_%08x]\n",
upper_32_bits(start), lower_32_bits(start),
upper_32_bits(end), lower_32_bits(end));
}
if (INTEL_GEN(m->i915) >= 4) {
err_printf(m, " BBADDR: 0x%08x_%08x\n",
(u32)(ee->bbaddr>>32), (u32)ee->bbaddr);
err_printf(m, " BB_STATE: 0x%08x\n", ee->bbstate);
err_printf(m, " INSTPS: 0x%08x\n", ee->instps);
}
err_printf(m, " INSTPM: 0x%08x\n", ee->instpm);
err_printf(m, " FADDR: 0x%08x %08x\n", upper_32_bits(ee->faddr),
lower_32_bits(ee->faddr));
if (INTEL_GEN(m->i915) >= 6) {
err_printf(m, " RC PSMI: 0x%08x\n", ee->rc_psmi);
err_printf(m, " FAULT_REG: 0x%08x\n", ee->fault_reg);
err_printf(m, " SYNC_0: 0x%08x [last synced 0x%08x]\n",
ee->semaphore_mboxes[0],
ee->semaphore_seqno[0]);
err_printf(m, " SYNC_1: 0x%08x [last synced 0x%08x]\n",
ee->semaphore_mboxes[1],
ee->semaphore_seqno[1]);
if (HAS_VEBOX(m->i915)) {
err_printf(m, " SYNC_2: 0x%08x [last synced 0x%08x]\n",
ee->semaphore_mboxes[2],
ee->semaphore_seqno[2]);
}
}
if (USES_PPGTT(m->i915)) {
err_printf(m, " GFX_MODE: 0x%08x\n", ee->vm_info.gfx_mode);
if (INTEL_GEN(m->i915) >= 8) {
int i;
for (i = 0; i < 4; i++)
err_printf(m, " PDP%d: 0x%016llx\n",
i, ee->vm_info.pdp[i]);
} else {
err_printf(m, " PP_DIR_BASE: 0x%08x\n",
ee->vm_info.pp_dir_base);
}
}
err_printf(m, " seqno: 0x%08x\n", ee->seqno);
err_printf(m, " last_seqno: 0x%08x\n", ee->last_seqno);
err_printf(m, " waiting: %s\n", yesno(ee->waiting));
err_printf(m, " ring->head: 0x%08x\n", ee->cpu_ring_head);
err_printf(m, " ring->tail: 0x%08x\n", ee->cpu_ring_tail);
err_printf(m, " hangcheck: %s [%d]\n",
hangcheck_action_to_str(ee->hangcheck_action),
ee->hangcheck_score);
}
void i915_error_printf(struct drm_i915_error_state_buf *e, const char *f, ...)
{
va_list args;
va_start(args, f);
i915_error_vprintf(e, f, args);
va_end(args);
}
static void print_error_obj(struct drm_i915_error_state_buf *m,
struct drm_i915_error_object *obj)
{
int page, offset, elt;
for (page = offset = 0; page < obj->page_count; page++) {
for (elt = 0; elt < PAGE_SIZE/4; elt++) {
err_printf(m, "%08x : %08x\n", offset,
obj->pages[page][elt]);
offset += 4;
}
}
}
static void err_print_capabilities(struct drm_i915_error_state_buf *m,
const struct intel_device_info *info)
{
#define PRINT_FLAG(x) err_printf(m, #x ": %s\n", yesno(info->x))
DEV_INFO_FOR_EACH_FLAG(PRINT_FLAG);
#undef PRINT_FLAG
}
int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
const struct i915_error_state_file_priv *error_priv)
{
struct drm_device *dev = error_priv->dev;
struct drm_i915_private *dev_priv = to_i915(dev);
struct pci_dev *pdev = dev_priv->drm.pdev;
struct drm_i915_error_state *error = error_priv->error;
struct drm_i915_error_object *obj;
int i, j, offset, elt;
int max_hangcheck_score;
if (!error) {
err_printf(m, "no error state collected\n");
goto out;
}
err_printf(m, "%s\n", error->error_msg);
err_printf(m, "Time: %ld s %ld us\n", error->time.tv_sec,
error->time.tv_usec);
err_printf(m, "Kernel: " UTS_RELEASE "\n");
err_print_capabilities(m, &error->device_info);
max_hangcheck_score = 0;
for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
if (error->engine[i].hangcheck_score > max_hangcheck_score)
max_hangcheck_score = error->engine[i].hangcheck_score;
}
for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
if (error->engine[i].hangcheck_score == max_hangcheck_score &&
error->engine[i].pid != -1) {
err_printf(m, "Active process (on ring %s): %s [%d]\n",
engine_str(i),
error->engine[i].comm,
error->engine[i].pid);
}
}
err_printf(m, "Reset count: %u\n", error->reset_count);
err_printf(m, "Suspend count: %u\n", error->suspend_count);
err_printf(m, "PCI ID: 0x%04x\n", pdev->device);
err_printf(m, "PCI Revision: 0x%02x\n", pdev->revision);
err_printf(m, "PCI Subsystem: %04x:%04x\n",
pdev->subsystem_vendor,
pdev->subsystem_device);
err_printf(m, "IOMMU enabled?: %d\n", error->iommu);
if (HAS_CSR(dev)) {
struct intel_csr *csr = &dev_priv->csr;
err_printf(m, "DMC loaded: %s\n",
yesno(csr->dmc_payload != NULL));
err_printf(m, "DMC fw version: %d.%d\n",
CSR_VERSION_MAJOR(csr->version),
CSR_VERSION_MINOR(csr->version));
}
err_printf(m, "EIR: 0x%08x\n", error->eir);
err_printf(m, "IER: 0x%08x\n", error->ier);
if (INTEL_INFO(dev)->gen >= 8) {
for (i = 0; i < 4; i++)
err_printf(m, "GTIER gt %d: 0x%08x\n", i,
error->gtier[i]);
} else if (HAS_PCH_SPLIT(dev) || IS_VALLEYVIEW(dev))
err_printf(m, "GTIER: 0x%08x\n", error->gtier[0]);
err_printf(m, "PGTBL_ER: 0x%08x\n", error->pgtbl_er);
err_printf(m, "FORCEWAKE: 0x%08x\n", error->forcewake);
err_printf(m, "DERRMR: 0x%08x\n", error->derrmr);
err_printf(m, "CCID: 0x%08x\n", error->ccid);
err_printf(m, "Missed interrupts: 0x%08lx\n", dev_priv->gpu_error.missed_irq_rings);
for (i = 0; i < dev_priv->num_fence_regs; i++)
err_printf(m, " fence[%d] = %08llx\n", i, error->fence[i]);
if (INTEL_INFO(dev)->gen >= 6) {
err_printf(m, "ERROR: 0x%08x\n", error->error);
if (INTEL_INFO(dev)->gen >= 8)
err_printf(m, "FAULT_TLB_DATA: 0x%08x 0x%08x\n",
error->fault_data1, error->fault_data0);
err_printf(m, "DONE_REG: 0x%08x\n", error->done_reg);
}
if (IS_GEN7(dev))
err_printf(m, "ERR_INT: 0x%08x\n", error->err_int);
for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
if (error->engine[i].engine_id != -1)
error_print_engine(m, &error->engine[i]);
}
for (i = 0; i < ARRAY_SIZE(error->active_vm); i++) {
char buf[128];
int len, first = 1;
if (!error->active_vm[i])
break;
len = scnprintf(buf, sizeof(buf), "Active (");
for (j = 0; j < ARRAY_SIZE(error->engine); j++) {
if (error->engine[j].vm != error->active_vm[i])
continue;
len += scnprintf(buf + len, sizeof(buf), "%s%s",
first ? "" : ", ",
dev_priv->engine[j].name);
first = 0;
}
scnprintf(buf + len, sizeof(buf), ")");
print_error_buffers(m, buf,
error->active_bo[i],
error->active_bo_count[i]);
}
print_error_buffers(m, "Pinned (global)",
error->pinned_bo,
error->pinned_bo_count);
for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
struct drm_i915_error_engine *ee = &error->engine[i];
obj = ee->batchbuffer;
if (obj) {
err_puts(m, dev_priv->engine[i].name);
if (ee->pid != -1)
err_printf(m, " (submitted by %s [%d])",
ee->comm,
ee->pid);
err_printf(m, " --- gtt_offset = 0x%08x %08x\n",
upper_32_bits(obj->gtt_offset),
lower_32_bits(obj->gtt_offset));
print_error_obj(m, obj);
}
obj = ee->wa_batchbuffer;
if (obj) {
err_printf(m, "%s (w/a) --- gtt_offset = 0x%08x\n",
dev_priv->engine[i].name,
lower_32_bits(obj->gtt_offset));
print_error_obj(m, obj);
}
if (ee->num_requests) {
err_printf(m, "%s --- %d requests\n",
dev_priv->engine[i].name,
ee->num_requests);
for (j = 0; j < ee->num_requests; j++) {
err_printf(m, " pid %d, seqno 0x%08x, emitted %ld, head 0x%08x, tail 0x%08x\n",
ee->requests[j].pid,
ee->requests[j].seqno,
ee->requests[j].jiffies,
ee->requests[j].head,
ee->requests[j].tail);
}
}
if (IS_ERR(ee->waiters)) {
err_printf(m, "%s --- ? waiters [unable to acquire spinlock]\n",
dev_priv->engine[i].name);
} else if (ee->num_waiters) {
err_printf(m, "%s --- %d waiters\n",
dev_priv->engine[i].name,
ee->num_waiters);
for (j = 0; j < ee->num_waiters; j++) {
err_printf(m, " seqno 0x%08x for %s [%d]\n",
ee->waiters[j].seqno,
ee->waiters[j].comm,
ee->waiters[j].pid);
}
}
if ((obj = ee->ringbuffer)) {
err_printf(m, "%s --- ringbuffer = 0x%08x\n",
dev_priv->engine[i].name,
lower_32_bits(obj->gtt_offset));
print_error_obj(m, obj);
}
if ((obj = ee->hws_page)) {
u64 hws_offset = obj->gtt_offset;
u32 *hws_page = &obj->pages[0][0];
if (i915.enable_execlists) {
hws_offset += LRC_PPHWSP_PN * PAGE_SIZE;
hws_page = &obj->pages[LRC_PPHWSP_PN][0];
}
err_printf(m, "%s --- HW Status = 0x%08llx\n",
dev_priv->engine[i].name, hws_offset);
offset = 0;
for (elt = 0; elt < PAGE_SIZE/16; elt += 4) {
err_printf(m, "[%04x] %08x %08x %08x %08x\n",
offset,
hws_page[elt],
hws_page[elt+1],
hws_page[elt+2],
hws_page[elt+3]);
offset += 16;
}
}
obj = ee->wa_ctx;
if (obj) {
u64 wa_ctx_offset = obj->gtt_offset;
u32 *wa_ctx_page = &obj->pages[0][0];
struct intel_engine_cs *engine = &dev_priv->engine[RCS];
u32 wa_ctx_size = (engine->wa_ctx.indirect_ctx.size +
engine->wa_ctx.per_ctx.size);
err_printf(m, "%s --- WA ctx batch buffer = 0x%08llx\n",
dev_priv->engine[i].name, wa_ctx_offset);
offset = 0;
for (elt = 0; elt < wa_ctx_size; elt += 4) {
err_printf(m, "[%04x] %08x %08x %08x %08x\n",
offset,
wa_ctx_page[elt + 0],
wa_ctx_page[elt + 1],
wa_ctx_page[elt + 2],
wa_ctx_page[elt + 3]);
offset += 16;
}
}
if ((obj = ee->ctx)) {
err_printf(m, "%s --- HW Context = 0x%08x\n",
dev_priv->engine[i].name,
lower_32_bits(obj->gtt_offset));
print_error_obj(m, obj);
}
}
if ((obj = error->semaphore)) {
err_printf(m, "Semaphore page = 0x%08x\n",
lower_32_bits(obj->gtt_offset));
for (elt = 0; elt < PAGE_SIZE/16; elt += 4) {
err_printf(m, "[%04x] %08x %08x %08x %08x\n",
elt * 4,
obj->pages[0][elt],
obj->pages[0][elt+1],
obj->pages[0][elt+2],
obj->pages[0][elt+3]);
}
}
if (error->overlay)
intel_overlay_print_error_state(m, error->overlay);
if (error->display)
intel_display_print_error_state(m, dev, error->display);
out:
if (m->bytes == 0 && m->err)
return m->err;
return 0;
}
int i915_error_state_buf_init(struct drm_i915_error_state_buf *ebuf,
struct drm_i915_private *i915,
size_t count, loff_t pos)
{
memset(ebuf, 0, sizeof(*ebuf));
ebuf->i915 = i915;
/* We need to have enough room to store any i915_error_state printf
* so that we can move it to start position.
*/
ebuf->size = count + 1 > PAGE_SIZE ? count + 1 : PAGE_SIZE;
ebuf->buf = kmalloc(ebuf->size,
GFP_TEMPORARY | __GFP_NORETRY | __GFP_NOWARN);
if (ebuf->buf == NULL) {
ebuf->size = PAGE_SIZE;
ebuf->buf = kmalloc(ebuf->size, GFP_TEMPORARY);
}
if (ebuf->buf == NULL) {
ebuf->size = 128;
ebuf->buf = kmalloc(ebuf->size, GFP_TEMPORARY);
}
if (ebuf->buf == NULL)
return -ENOMEM;
ebuf->start = pos;
return 0;
}
static void i915_error_object_free(struct drm_i915_error_object *obj)
{
int page;
if (obj == NULL)
return;
for (page = 0; page < obj->page_count; page++)
kfree(obj->pages[page]);
kfree(obj);
}
static void i915_error_state_free(struct kref *error_ref)
{
struct drm_i915_error_state *error = container_of(error_ref,
typeof(*error), ref);
int i;
for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
struct drm_i915_error_engine *ee = &error->engine[i];
i915_error_object_free(ee->batchbuffer);
i915_error_object_free(ee->wa_batchbuffer);
i915_error_object_free(ee->ringbuffer);
i915_error_object_free(ee->hws_page);
i915_error_object_free(ee->ctx);
i915_error_object_free(ee->wa_ctx);
kfree(ee->requests);
if (!IS_ERR_OR_NULL(ee->waiters))
kfree(ee->waiters);
}
i915_error_object_free(error->semaphore);
for (i = 0; i < ARRAY_SIZE(error->active_bo); i++)
kfree(error->active_bo[i]);
kfree(error->pinned_bo);
kfree(error->overlay);
kfree(error->display);
kfree(error);
}
static struct drm_i915_error_object *
i915_error_object_create(struct drm_i915_private *dev_priv,
struct i915_vma *vma)
{
struct i915_ggtt *ggtt = &dev_priv->ggtt;
struct drm_i915_gem_object *src;
struct drm_i915_error_object *dst;
int num_pages;
bool use_ggtt;
int i = 0;
u64 reloc_offset;
if (!vma)
return NULL;
src = vma->obj;
if (!src->pages)
return NULL;
num_pages = src->base.size >> PAGE_SHIFT;
dst = kmalloc(sizeof(*dst) + num_pages * sizeof(u32 *), GFP_ATOMIC);
if (!dst)
return NULL;
dst->gtt_offset = vma->node.start;
dst->gtt_size = vma->node.size;
reloc_offset = dst->gtt_offset;
use_ggtt = (src->cache_level == I915_CACHE_NONE &&
(vma->flags & I915_VMA_GLOBAL_BIND) &&
reloc_offset + num_pages * PAGE_SIZE <= ggtt->mappable_end);
/* Cannot access stolen address directly, try to use the aperture */
if (src->stolen) {
use_ggtt = true;
if (!(vma->flags & I915_VMA_GLOBAL_BIND))
goto unwind;
reloc_offset = vma->node.start;
if (reloc_offset + num_pages * PAGE_SIZE > ggtt->mappable_end)
goto unwind;
}
/* Cannot access snooped pages through the aperture */
if (use_ggtt && src->cache_level != I915_CACHE_NONE &&
!HAS_LLC(dev_priv))
goto unwind;
dst->page_count = num_pages;
while (num_pages--) {
unsigned long flags;
void *d;
d = kmalloc(PAGE_SIZE, GFP_ATOMIC);
if (d == NULL)
goto unwind;
local_irq_save(flags);
if (use_ggtt) {
void __iomem *s;
/* Simply ignore tiling or any overlapping fence.
* It's part of the error state, and this hopefully
* captures what the GPU read.
*/
s = io_mapping_map_atomic_wc(&ggtt->mappable,
reloc_offset);
memcpy_fromio(d, s, PAGE_SIZE);
io_mapping_unmap_atomic(s);
} else {
struct page *page;
void *s;
page = i915_gem_object_get_page(src, i);
drm_clflush_pages(&page, 1);
s = kmap_atomic(page);
memcpy(d, s, PAGE_SIZE);
kunmap_atomic(s);
drm_clflush_pages(&page, 1);
}
local_irq_restore(flags);
dst->pages[i++] = d;
reloc_offset += PAGE_SIZE;
}
return dst;
unwind:
while (i--)
kfree(dst->pages[i]);
kfree(dst);
return NULL;
}
/* The error capture is special as tries to run underneath the normal
* locking rules - so we use the raw version of the i915_gem_active lookup.
*/
static inline uint32_t
__active_get_seqno(struct i915_gem_active *active)
{
return i915_gem_request_get_seqno(__i915_gem_active_peek(active));
}
static inline int
__active_get_engine_id(struct i915_gem_active *active)
{
struct intel_engine_cs *engine;
engine = i915_gem_request_get_engine(__i915_gem_active_peek(active));
return engine ? engine->id : -1;
}
static void capture_bo(struct drm_i915_error_buffer *err,
struct i915_vma *vma)
{
struct drm_i915_gem_object *obj = vma->obj;
int i;
err->size = obj->base.size;
err->name = obj->base.name;
for (i = 0; i < I915_NUM_ENGINES; i++)
err->rseqno[i] = __active_get_seqno(&obj->last_read[i]);
err->wseqno = __active_get_seqno(&obj->last_write);
err->engine = __active_get_engine_id(&obj->last_write);
err->gtt_offset = vma->node.start;
err->read_domains = obj->base.read_domains;
err->write_domain = obj->base.write_domain;
err->fence_reg = vma->fence ? vma->fence->id : -1;
err->tiling = i915_gem_object_get_tiling(obj);
err->dirty = obj->dirty;
err->purgeable = obj->madv != I915_MADV_WILLNEED;
err->userptr = obj->userptr.mm != NULL;
err->cache_level = obj->cache_level;
}
static u32 capture_error_bo(struct drm_i915_error_buffer *err,
int count, struct list_head *head,
bool pinned_only)
{
struct i915_vma *vma;
int i = 0;
list_for_each_entry(vma, head, vm_link) {
if (pinned_only && !i915_vma_is_pinned(vma))
continue;
capture_bo(err++, vma);
if (++i == count)
break;
}
return i;
}
/* Generate a semi-unique error code. The code is not meant to have meaning, The
* code's only purpose is to try to prevent false duplicated bug reports by
* grossly estimating a GPU error state.
*
* TODO Ideally, hashing the batchbuffer would be a very nice way to determine
* the hang if we could strip the GTT offset information from it.
*
* It's only a small step better than a random number in its current form.
*/
static uint32_t i915_error_generate_code(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error,
int *engine_id)
{
uint32_t error_code = 0;
int i;
/* IPEHR would be an ideal way to detect errors, as it's the gross
* measure of "the command that hung." However, has some very common
* synchronization commands which almost always appear in the case
* strictly a client bug. Use instdone to differentiate those some.
*/
for (i = 0; i < I915_NUM_ENGINES; i++) {
if (error->engine[i].hangcheck_action == HANGCHECK_HUNG) {
if (engine_id)
*engine_id = i;
return error->engine[i].ipehr ^
error->engine[i].instdone.instdone;
}
}
return error_code;
}
static void i915_gem_record_fences(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error)
{
int i;
if (IS_GEN3(dev_priv) || IS_GEN2(dev_priv)) {
for (i = 0; i < dev_priv->num_fence_regs; i++)
error->fence[i] = I915_READ(FENCE_REG(i));
} else if (IS_GEN5(dev_priv) || IS_GEN4(dev_priv)) {
for (i = 0; i < dev_priv->num_fence_regs; i++)
error->fence[i] = I915_READ64(FENCE_REG_965_LO(i));
} else if (INTEL_GEN(dev_priv) >= 6) {
for (i = 0; i < dev_priv->num_fence_regs; i++)
error->fence[i] = I915_READ64(FENCE_REG_GEN6_LO(i));
}
}
static void gen8_record_semaphore_state(struct drm_i915_error_state *error,
struct intel_engine_cs *engine,
struct drm_i915_error_engine *ee)
{
struct drm_i915_private *dev_priv = engine->i915;
struct intel_engine_cs *to;
enum intel_engine_id id;
if (!error->semaphore)
return;
for_each_engine_id(to, dev_priv, id) {
int idx;
u16 signal_offset;
u32 *tmp;
if (engine == to)
continue;
signal_offset =
(GEN8_SIGNAL_OFFSET(engine, id) & (PAGE_SIZE - 1)) / 4;
tmp = error->semaphore->pages[0];
idx = intel_engine_sync_index(engine, to);
ee->semaphore_mboxes[idx] = tmp[signal_offset];
ee->semaphore_seqno[idx] = engine->semaphore.sync_seqno[idx];
}
}
static void gen6_record_semaphore_state(struct intel_engine_cs *engine,
struct drm_i915_error_engine *ee)
{
struct drm_i915_private *dev_priv = engine->i915;
ee->semaphore_mboxes[0] = I915_READ(RING_SYNC_0(engine->mmio_base));
ee->semaphore_mboxes[1] = I915_READ(RING_SYNC_1(engine->mmio_base));
ee->semaphore_seqno[0] = engine->semaphore.sync_seqno[0];
ee->semaphore_seqno[1] = engine->semaphore.sync_seqno[1];
if (HAS_VEBOX(dev_priv)) {
ee->semaphore_mboxes[2] =
I915_READ(RING_SYNC_2(engine->mmio_base));
ee->semaphore_seqno[2] = engine->semaphore.sync_seqno[2];
}
}
static void error_record_engine_waiters(struct intel_engine_cs *engine,
struct drm_i915_error_engine *ee)
{
struct intel_breadcrumbs *b = &engine->breadcrumbs;
struct drm_i915_error_waiter *waiter;
struct rb_node *rb;
int count;
ee->num_waiters = 0;
ee->waiters = NULL;
if (RB_EMPTY_ROOT(&b->waiters))
return;
if (!spin_trylock(&b->lock)) {
ee->waiters = ERR_PTR(-EDEADLK);
return;
}
count = 0;
for (rb = rb_first(&b->waiters); rb != NULL; rb = rb_next(rb))
count++;
spin_unlock(&b->lock);
waiter = NULL;
if (count)
waiter = kmalloc_array(count,
sizeof(struct drm_i915_error_waiter),
GFP_ATOMIC);
if (!waiter)
return;
if (!spin_trylock(&b->lock)) {
kfree(waiter);
ee->waiters = ERR_PTR(-EDEADLK);
return;
}
ee->waiters = waiter;
for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
struct intel_wait *w = container_of(rb, typeof(*w), node);
strcpy(waiter->comm, w->tsk->comm);
waiter->pid = w->tsk->pid;
waiter->seqno = w->seqno;
waiter++;
if (++ee->num_waiters == count)
break;
}
spin_unlock(&b->lock);
}
static void error_record_engine_registers(struct drm_i915_error_state *error,
struct intel_engine_cs *engine,
struct drm_i915_error_engine *ee)
{
struct drm_i915_private *dev_priv = engine->i915;
if (INTEL_GEN(dev_priv) >= 6) {
ee->rc_psmi = I915_READ(RING_PSMI_CTL(engine->mmio_base));
ee->fault_reg = I915_READ(RING_FAULT_REG(engine));
if (INTEL_GEN(dev_priv) >= 8)
gen8_record_semaphore_state(error, engine, ee);
else
gen6_record_semaphore_state(engine, ee);
}
if (INTEL_GEN(dev_priv) >= 4) {
ee->faddr = I915_READ(RING_DMA_FADD(engine->mmio_base));
ee->ipeir = I915_READ(RING_IPEIR(engine->mmio_base));
ee->ipehr = I915_READ(RING_IPEHR(engine->mmio_base));
ee->instps = I915_READ(RING_INSTPS(engine->mmio_base));
ee->bbaddr = I915_READ(RING_BBADDR(engine->mmio_base));
if (INTEL_GEN(dev_priv) >= 8) {
ee->faddr |= (u64) I915_READ(RING_DMA_FADD_UDW(engine->mmio_base)) << 32;
ee->bbaddr |= (u64) I915_READ(RING_BBADDR_UDW(engine->mmio_base)) << 32;
}
ee->bbstate = I915_READ(RING_BBSTATE(engine->mmio_base));
} else {
ee->faddr = I915_READ(DMA_FADD_I8XX);
ee->ipeir = I915_READ(IPEIR);
ee->ipehr = I915_READ(IPEHR);
}
intel_engine_get_instdone(engine, &ee->instdone);
ee->waiting = intel_engine_has_waiter(engine);
ee->instpm = I915_READ(RING_INSTPM(engine->mmio_base));
ee->acthd = intel_engine_get_active_head(engine);
ee->seqno = intel_engine_get_seqno(engine);
ee->last_seqno = engine->last_submitted_seqno;
ee->start = I915_READ_START(engine);
ee->head = I915_READ_HEAD(engine);
ee->tail = I915_READ_TAIL(engine);
ee->ctl = I915_READ_CTL(engine);
if (INTEL_GEN(dev_priv) > 2)
ee->mode = I915_READ_MODE(engine);
if (!HWS_NEEDS_PHYSICAL(dev_priv)) {
i915_reg_t mmio;
if (IS_GEN7(dev_priv)) {
switch (engine->id) {
default:
case RCS:
mmio = RENDER_HWS_PGA_GEN7;
break;
case BCS:
mmio = BLT_HWS_PGA_GEN7;
break;
case VCS:
mmio = BSD_HWS_PGA_GEN7;
break;
case VECS:
mmio = VEBOX_HWS_PGA_GEN7;
break;
}
} else if (IS_GEN6(engine->i915)) {
mmio = RING_HWS_PGA_GEN6(engine->mmio_base);
} else {
/* XXX: gen8 returns to sanity */
mmio = RING_HWS_PGA(engine->mmio_base);
}
ee->hws = I915_READ(mmio);
}
ee->hangcheck_score = engine->hangcheck.score;
ee->hangcheck_action = engine->hangcheck.action;
if (USES_PPGTT(dev_priv)) {
int i;
ee->vm_info.gfx_mode = I915_READ(RING_MODE_GEN7(engine));
if (IS_GEN6(dev_priv))
ee->vm_info.pp_dir_base =
I915_READ(RING_PP_DIR_BASE_READ(engine));
else if (IS_GEN7(dev_priv))
ee->vm_info.pp_dir_base =
I915_READ(RING_PP_DIR_BASE(engine));
else if (INTEL_GEN(dev_priv) >= 8)
for (i = 0; i < 4; i++) {
ee->vm_info.pdp[i] =
I915_READ(GEN8_RING_PDP_UDW(engine, i));
ee->vm_info.pdp[i] <<= 32;
ee->vm_info.pdp[i] |=
I915_READ(GEN8_RING_PDP_LDW(engine, i));
}
}
}
static void engine_record_requests(struct intel_engine_cs *engine,
struct drm_i915_gem_request *first,
struct drm_i915_error_engine *ee)
{
struct drm_i915_gem_request *request;
int count;
count = 0;
request = first;
list_for_each_entry_from(request, &engine->request_list, link)
count++;
if (!count)
return;
ee->requests = kcalloc(count, sizeof(*ee->requests), GFP_ATOMIC);
if (!ee->requests)
return;
ee->num_requests = count;
count = 0;
request = first;
list_for_each_entry_from(request, &engine->request_list, link) {
struct drm_i915_error_request *erq;
if (count >= ee->num_requests) {
/*
* If the ring request list was changed in
* between the point where the error request
* list was created and dimensioned and this
* point then just exit early to avoid crashes.
*
* We don't need to communicate that the
* request list changed state during error
* state capture and that the error state is
* slightly incorrect as a consequence since we
* are typically only interested in the request
* list state at the point of error state
* capture, not in any changes happening during
* the capture.
*/
break;
}
erq = &ee->requests[count++];
erq->seqno = request->fence.seqno;
erq->jiffies = request->emitted_jiffies;
erq->head = request->head;
erq->tail = request->tail;
rcu_read_lock();
erq->pid = request->ctx->pid ? pid_nr(request->ctx->pid) : 0;
rcu_read_unlock();
}
ee->num_requests = count;
}
static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error)
{
struct i915_ggtt *ggtt = &dev_priv->ggtt;
int i;
error->semaphore =
i915_error_object_create(dev_priv, dev_priv->semaphore);
for (i = 0; i < I915_NUM_ENGINES; i++) {
struct intel_engine_cs *engine = &dev_priv->engine[i];
struct drm_i915_error_engine *ee = &error->engine[i];
struct drm_i915_gem_request *request;
ee->pid = -1;
ee->engine_id = -1;
if (!intel_engine_initialized(engine))
continue;
ee->engine_id = i;
error_record_engine_registers(error, engine, ee);
error_record_engine_waiters(engine, ee);
request = i915_gem_find_active_request(engine);
if (request) {
struct intel_ring *ring;
struct pid *pid;
ee->vm = request->ctx->ppgtt ?
&request->ctx->ppgtt->base : &ggtt->base;
/* We need to copy these to an anonymous buffer
* as the simplest method to avoid being overwritten
* by userspace.
*/
ee->batchbuffer =
i915_error_object_create(dev_priv,
request->batch);
if (HAS_BROKEN_CS_TLB(dev_priv))
ee->wa_batchbuffer =
i915_error_object_create(dev_priv,
engine->scratch);
ee->ctx =
i915_error_object_create(dev_priv,
request->ctx->engine[i].state);
pid = request->ctx->pid;
if (pid) {
struct task_struct *task;
rcu_read_lock();
task = pid_task(pid, PIDTYPE_PID);
if (task) {
strcpy(ee->comm, task->comm);
ee->pid = task->pid;
}
rcu_read_unlock();
}
error->simulated |=
request->ctx->flags & CONTEXT_NO_ERROR_CAPTURE;
ee->rq_head = request->head;
ee->rq_post = request->postfix;
ee->rq_tail = request->tail;
ring = request->ring;
ee->cpu_ring_head = ring->head;
ee->cpu_ring_tail = ring->tail;
ee->ringbuffer =
i915_error_object_create(dev_priv, ring->vma);
engine_record_requests(engine, request, ee);
}
ee->hws_page =
i915_error_object_create(dev_priv,
engine->status_page.vma);
ee->wa_ctx =
i915_error_object_create(dev_priv, engine->wa_ctx.vma);
}
}
static void i915_gem_capture_vm(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error,
struct i915_address_space *vm,
int idx)
{
struct drm_i915_error_buffer *active_bo;
struct i915_vma *vma;
int count;
count = 0;
list_for_each_entry(vma, &vm->active_list, vm_link)
count++;
active_bo = NULL;
if (count)
active_bo = kcalloc(count, sizeof(*active_bo), GFP_ATOMIC);
if (active_bo)
count = capture_error_bo(active_bo, count, &vm->active_list, false);
else
count = 0;
error->active_vm[idx] = vm;
error->active_bo[idx] = active_bo;
error->active_bo_count[idx] = count;
}
static void i915_capture_active_buffers(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error)
{
int cnt = 0, i, j;
BUILD_BUG_ON(ARRAY_SIZE(error->engine) > ARRAY_SIZE(error->active_bo));
BUILD_BUG_ON(ARRAY_SIZE(error->active_bo) != ARRAY_SIZE(error->active_vm));
BUILD_BUG_ON(ARRAY_SIZE(error->active_bo) != ARRAY_SIZE(error->active_bo_count));
/* Scan each engine looking for unique active contexts/vm */
for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
struct drm_i915_error_engine *ee = &error->engine[i];
bool found;
if (!ee->vm)
continue;
found = false;
for (j = 0; j < i && !found; j++)
found = error->engine[j].vm == ee->vm;
if (!found)
i915_gem_capture_vm(dev_priv, error, ee->vm, cnt++);
}
}
static void i915_capture_pinned_buffers(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error)
{
struct i915_address_space *vm = &dev_priv->ggtt.base;
struct drm_i915_error_buffer *bo;
struct i915_vma *vma;
int count_inactive, count_active;
count_inactive = 0;
list_for_each_entry(vma, &vm->active_list, vm_link)
count_inactive++;
count_active = 0;
list_for_each_entry(vma, &vm->inactive_list, vm_link)
count_active++;
bo = NULL;
if (count_inactive + count_active)
bo = kcalloc(count_inactive + count_active,
sizeof(*bo), GFP_ATOMIC);
if (!bo)
return;
count_inactive = capture_error_bo(bo, count_inactive,
&vm->active_list, true);
count_active = capture_error_bo(bo + count_inactive, count_active,
&vm->inactive_list, true);
error->pinned_bo_count = count_inactive + count_active;
error->pinned_bo = bo;
}
/* Capture all registers which don't fit into another category. */
static void i915_capture_reg_state(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error)
{
struct drm_device *dev = &dev_priv->drm;
int i;
/* General organization
* 1. Registers specific to a single generation
* 2. Registers which belong to multiple generations
* 3. Feature specific registers.
* 4. Everything else
* Please try to follow the order.
*/
/* 1: Registers specific to a single generation */
if (IS_VALLEYVIEW(dev)) {
error->gtier[0] = I915_READ(GTIER);
error->ier = I915_READ(VLV_IER);
error->forcewake = I915_READ_FW(FORCEWAKE_VLV);
}
if (IS_GEN7(dev))
error->err_int = I915_READ(GEN7_ERR_INT);
if (INTEL_INFO(dev)->gen >= 8) {
error->fault_data0 = I915_READ(GEN8_FAULT_TLB_DATA0);
error->fault_data1 = I915_READ(GEN8_FAULT_TLB_DATA1);
}
if (IS_GEN6(dev)) {
error->forcewake = I915_READ_FW(FORCEWAKE);
error->gab_ctl = I915_READ(GAB_CTL);
error->gfx_mode = I915_READ(GFX_MODE);
}
/* 2: Registers which belong to multiple generations */
if (INTEL_INFO(dev)->gen >= 7)
error->forcewake = I915_READ_FW(FORCEWAKE_MT);
if (INTEL_INFO(dev)->gen >= 6) {
error->derrmr = I915_READ(DERRMR);
error->error = I915_READ(ERROR_GEN6);
error->done_reg = I915_READ(DONE_REG);
}
/* 3: Feature specific registers */
if (IS_GEN6(dev) || IS_GEN7(dev)) {
error->gam_ecochk = I915_READ(GAM_ECOCHK);
error->gac_eco = I915_READ(GAC_ECO_BITS);
}
/* 4: Everything else */
if (HAS_HW_CONTEXTS(dev))
error->ccid = I915_READ(CCID);
if (INTEL_INFO(dev)->gen >= 8) {
error->ier = I915_READ(GEN8_DE_MISC_IER);
for (i = 0; i < 4; i++)
error->gtier[i] = I915_READ(GEN8_GT_IER(i));
} else if (HAS_PCH_SPLIT(dev)) {
error->ier = I915_READ(DEIER);
error->gtier[0] = I915_READ(GTIER);
} else if (IS_GEN2(dev)) {
error->ier = I915_READ16(IER);
} else if (!IS_VALLEYVIEW(dev)) {
error->ier = I915_READ(IER);
}
error->eir = I915_READ(EIR);
error->pgtbl_er = I915_READ(PGTBL_ER);
}
static void i915_error_capture_msg(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error,
u32 engine_mask,
const char *error_msg)
{
u32 ecode;
int engine_id = -1, len;
ecode = i915_error_generate_code(dev_priv, error, &engine_id);
len = scnprintf(error->error_msg, sizeof(error->error_msg),
"GPU HANG: ecode %d:%d:0x%08x",
INTEL_GEN(dev_priv), engine_id, ecode);
if (engine_id != -1 && error->engine[engine_id].pid != -1)
len += scnprintf(error->error_msg + len,
sizeof(error->error_msg) - len,
", in %s [%d]",
error->engine[engine_id].comm,
error->engine[engine_id].pid);
scnprintf(error->error_msg + len, sizeof(error->error_msg) - len,
", reason: %s, action: %s",
error_msg,
engine_mask ? "reset" : "continue");
}
static void i915_capture_gen_state(struct drm_i915_private *dev_priv,
struct drm_i915_error_state *error)
{
error->iommu = -1;
#ifdef CONFIG_INTEL_IOMMU
error->iommu = intel_iommu_gfx_mapped;
#endif
error->reset_count = i915_reset_count(&dev_priv->gpu_error);
error->suspend_count = dev_priv->suspend_count;
memcpy(&error->device_info,
INTEL_INFO(dev_priv),
sizeof(error->device_info));
}
/**
* i915_capture_error_state - capture an error record for later analysis
* @dev: drm device
*
* Should be called when an error is detected (either a hang or an error
* interrupt) to capture error state from the time of the error. Fills
* out a structure which becomes available in debugfs for user level tools
* to pick up.
*/
void i915_capture_error_state(struct drm_i915_private *dev_priv,
u32 engine_mask,
const char *error_msg)
{
static bool warned;
struct drm_i915_error_state *error;
unsigned long flags;
if (!i915.error_capture)
return;
if (READ_ONCE(dev_priv->gpu_error.first_error))
return;
/* Account for pipe specific data like PIPE*STAT */
error = kzalloc(sizeof(*error), GFP_ATOMIC);
if (!error) {
DRM_DEBUG_DRIVER("out of memory, not capturing error state\n");
return;
}
kref_init(&error->ref);
i915_capture_gen_state(dev_priv, error);
i915_capture_reg_state(dev_priv, error);
i915_gem_record_fences(dev_priv, error);
i915_gem_record_rings(dev_priv, error);
i915_capture_active_buffers(dev_priv, error);
i915_capture_pinned_buffers(dev_priv, error);
do_gettimeofday(&error->time);
error->overlay = intel_overlay_capture_error_state(dev_priv);
error->display = intel_display_capture_error_state(dev_priv);
i915_error_capture_msg(dev_priv, error, engine_mask, error_msg);
DRM_INFO("%s\n", error->error_msg);
if (!error->simulated) {
spin_lock_irqsave(&dev_priv->gpu_error.lock, flags);
if (!dev_priv->gpu_error.first_error) {
dev_priv->gpu_error.first_error = error;
error = NULL;
}
spin_unlock_irqrestore(&dev_priv->gpu_error.lock, flags);
}
if (error) {
i915_error_state_free(&error->ref);
return;
}
if (!warned) {
DRM_INFO("GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.\n");
DRM_INFO("Please file a _new_ bug report on bugs.freedesktop.org against DRI -> DRM/Intel\n");
DRM_INFO("drm/i915 developers can then reassign to the right component if it's not a kernel issue.\n");
DRM_INFO("The gpu crash dump is required to analyze gpu hangs, so please always attach it.\n");
DRM_INFO("GPU crash dump saved to /sys/class/drm/card%d/error\n",
dev_priv->drm.primary->index);
warned = true;
}
}
void i915_error_state_get(struct drm_device *dev,
struct i915_error_state_file_priv *error_priv)
{
struct drm_i915_private *dev_priv = to_i915(dev);
spin_lock_irq(&dev_priv->gpu_error.lock);
error_priv->error = dev_priv->gpu_error.first_error;
if (error_priv->error)
kref_get(&error_priv->error->ref);
spin_unlock_irq(&dev_priv->gpu_error.lock);
}
void i915_error_state_put(struct i915_error_state_file_priv *error_priv)
{
if (error_priv->error)
kref_put(&error_priv->error->ref, i915_error_state_free);
}
void i915_destroy_error_state(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct drm_i915_error_state *error;
spin_lock_irq(&dev_priv->gpu_error.lock);
error = dev_priv->gpu_error.first_error;
dev_priv->gpu_error.first_error = NULL;
spin_unlock_irq(&dev_priv->gpu_error.lock);
if (error)
kref_put(&error->ref, i915_error_state_free);
}