Re: [PATCH v2] drm/i915: Avoid using intel_engine_cs *ring for GPU error capture

Joonas Lahtinen
2016-07-26T12:35:44Z

On ti, 2016-07-26 at 11:21 +0100, Chris Wilson wrote:
> Inside the error capture itself, we refer to not only the hardware
> engine, its ringbuffer but also the capture state. Finding clear names
> for each whilst avoiding mixing ring/intel_engine_cs is tricky. As a
> compromise we keep using ering for the error capture.
>
> v2: Use 'ee' locals for struct drm_i915_error_engine

Assuming this is the change, looks good now;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

>
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Link: http://patchwork.freedesktop.org/patch/msgid/1469432687-22756-8-git-send-email-chris@chris-wilson.co.uk
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_drv.h       |   8 +-
>  drivers/gpu/drm/i915/i915_gpu_error.c | 403 +++++++++++++++++-----------------
>  2 files changed, 208 insertions(+), 203 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 97f827979a66..65ada5d2f88c 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -512,8 +512,8 @@ struct drm_i915_error_state {
>   struct intel_display_error_state *display;
>   struct drm_i915_error_object *semaphore_obj;
>
> - struct drm_i915_error_ring {
> - bool valid;
> + struct drm_i915_error_engine {
> + int engine_id;
>   /* Software tracked state */
>   bool waiting;
>   int num_waiters;
> @@ -578,7 +578,7 @@ struct drm_i915_error_state {
>
>   pid_t pid;
>   char comm[TASK_COMM_LEN];
> - } ring[I915_NUM_ENGINES];
> + } engine[I915_NUM_ENGINES];
>
>   struct drm_i915_error_buffer {
>   u32 size;
> @@ -593,7 +593,7 @@ struct drm_i915_error_state {
>   u32 dirty:1;
>   u32 purgeable:1;
>   u32 userptr:1;
> - s32 ring:4;
> + s32 engine:4;
>   u32 cache_level:3;
>   } **active_bo, **pinned_bo;
>
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 4d39c7284605..bc4a3ebc2662 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -30,9 +30,9 @@
>  #include
>  #include "i915_drv.h"
>
> -static const char *ring_str(int ring)
> +static const char *engine_str(int engine)
>  {
> - switch (ring) {
> + switch (engine) {
>   case RCS: return "render";
>   case VCS: return "bsd";
>   case BCS: return "blt";
> @@ -207,8 +207,8 @@ static void print_error_buffers(struct drm_i915_error_state_buf *m,
>   err_puts(m, dirty_flag(err->dirty));
>   err_puts(m, purgeable_flag(err->purgeable));
>   err_puts(m, err->userptr ? " userptr" : "");
> - err_puts(m, err->ring != -1 ? " " : "");
> - err_puts(m, ring_str(err->ring));
> + 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)
> @@ -239,70 +239,65 @@ static const char *hangcheck_action_to_str(enum intel_ring_hangcheck_action a)
>   return "unknown";
>  }
>
> -static void i915_ring_error_state(struct drm_i915_error_state_buf *m,
> -   struct drm_device *dev,
> -   struct drm_i915_error_state *error,
> -   int ring_idx)
> +static void error_print_engine(struct drm_i915_error_state_buf *m,
> +        struct drm_i915_error_engine *ee)
>  {
> - struct drm_i915_error_ring *ring = &error->ring[ring_idx];
> -
> - if (!ring->valid)
> - return;
> -
> - err_printf(m, "%s command stream:\n", ring_str(ring_idx));
> - err_printf(m, "  START: 0x%08x\n", ring->start);
> - err_printf(m, "  HEAD:  0x%08x\n", ring->head);
> - err_printf(m, "  TAIL:  0x%08x\n", ring->tail);
> - err_printf(m, "  CTL:   0x%08x\n", ring->ctl);
> - err_printf(m, "  HWS:   0x%08x\n", ring->hws);
> - err_printf(m, "  ACTHD: 0x%08x %08x\n", (u32)(ring->acthd>>32), (u32)ring->acthd);
> - err_printf(m, "  IPEIR: 0x%08x\n", ring->ipeir);
> - err_printf(m, "  IPEHR: 0x%08x\n", ring->ipehr);
> - err_printf(m, "  INSTDONE: 0x%08x\n", ring->instdone);
> - if (INTEL_INFO(dev)->gen >= 4) {
> - err_printf(m, "  BBADDR: 0x%08x %08x\n", (u32)(ring->bbaddr>>32), (u32)ring->bbaddr);
> - err_printf(m, "  BB_STATE: 0x%08x\n", ring->bbstate);
> - err_printf(m, "  INSTPS: 0x%08x\n", ring->instps);
> + 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", ee->head);
> + err_printf(m, "  TAIL:  0x%08x\n", ee->tail);
> + err_printf(m, "  CTL:   0x%08x\n", ee->ctl);
> + 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);
> + err_printf(m, "  INSTDONE: 0x%08x\n", ee->instdone);
> + 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", ring->instpm);
> - err_printf(m, "  FADDR: 0x%08x %08x\n", upper_32_bits(ring->faddr),
> -    lower_32_bits(ring->faddr));
> - if (INTEL_INFO(dev)->gen >= 6) {
> - err_printf(m, "  RC PSMI: 0x%08x\n", ring->rc_psmi);
> - err_printf(m, "  FAULT_REG: 0x%08x\n", ring->fault_reg);
> + 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",
> -    ring->semaphore_mboxes[0],
> -    ring->semaphore_seqno[0]);
> +    ee->semaphore_mboxes[0],
> +    ee->semaphore_seqno[0]);
>   err_printf(m, "  SYNC_1: 0x%08x [last synced 0x%08x]\n",
> -    ring->semaphore_mboxes[1],
> -    ring->semaphore_seqno[1]);
> - if (HAS_VEBOX(dev)) {
> +    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",
> -    ring->semaphore_mboxes[2],
> -    ring->semaphore_seqno[2]);
> +    ee->semaphore_mboxes[2],
> +    ee->semaphore_seqno[2]);
>   }
>   }
> - if (USES_PPGTT(dev)) {
> - err_printf(m, "  GFX_MODE: 0x%08x\n", ring->vm_info.gfx_mode);
> + if (USES_PPGTT(m->i915)) {
> + err_printf(m, "  GFX_MODE: 0x%08x\n", ee->vm_info.gfx_mode);
>
> - if (INTEL_INFO(dev)->gen >= 8) {
> + if (INTEL_GEN(m->i915) >= 8) {
>   int i;
>   for (i = 0; i < 4; i++)
>   err_printf(m, "  PDP%d: 0x%016llx\n",
> -    i, ring->vm_info.pdp[i]);
> +    i, ee->vm_info.pdp[i]);
>   } else {
>   err_printf(m, "  PP_DIR_BASE: 0x%08x\n",
> -    ring->vm_info.pp_dir_base);
> +    ee->vm_info.pp_dir_base);
>   }
>   }
> - err_printf(m, "  seqno: 0x%08x\n", ring->seqno);
> - err_printf(m, "  last_seqno: 0x%08x\n", ring->last_seqno);
> - err_printf(m, "  waiting: %s\n", yesno(ring->waiting));
> - err_printf(m, "  ring->head: 0x%08x\n", ring->cpu_ring_head);
> - err_printf(m, "  ring->tail: 0x%08x\n", ring->cpu_ring_tail);
> + 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(ring->hangcheck_action),
> -    ring->hangcheck_score);
> +    hangcheck_action_to_str(ee->hangcheck_action),
> +    ee->hangcheck_score);
>  }
>
>  void i915_error_printf(struct drm_i915_error_state_buf *e, const char *f, ...)
> @@ -348,17 +343,17 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>      error->time.tv_usec);
>   err_printf(m, "Kernel: " UTS_RELEASE "\n");
>   max_hangcheck_score = 0;
> - for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
> - if (error->ring[i].hangcheck_score > max_hangcheck_score)
> - max_hangcheck_score = error->ring[i].hangcheck_score;
> + 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->ring); i++) {
> - if (error->ring[i].hangcheck_score == max_hangcheck_score &&
> -     error->ring[i].pid != -1) {
> + 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",
> -    ring_str(i),
> -    error->ring[i].comm,
> -    error->ring[i].pid);
> +    engine_str(i),
> +    error->engine[i].comm,
> +    error->engine[i].pid);
>   }
>   }
>   err_printf(m, "Reset count: %u\n", error->reset_count);
> @@ -414,8 +409,10 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>   if (IS_GEN7(dev))
>   err_printf(m, "ERR_INT: 0x%08x\n", error->err_int);
>
> - for (i = 0; i < ARRAY_SIZE(error->ring); i++)
> - i915_ring_error_state(m, dev, error, i);
> + 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 < error->vm_count; i++) {
>   err_printf(m, "vm[%d]\n", i);
> @@ -429,21 +426,23 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>       error->pinned_bo_count[i]);
>   }
>
> - for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
> - obj = error->ring[i].batchbuffer;
> + 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 (error->ring[i].pid != -1)
> + if (ee->pid != -1)
>   err_printf(m, " (submitted by %s [%d])",
> -    error->ring[i].comm,
> -    error->ring[i].pid);
> +    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 = error->ring[i].wa_batchbuffer;
> + obj = ee->wa_batchbuffer;
>   if (obj) {
>   err_printf(m, "%s (w/a) --- gtt_offset = 0x%08x\n",
>      dev_priv->engine[i].name,
> @@ -451,38 +450,38 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>   print_error_obj(m, obj);
>   }
>
> - if (error->ring[i].num_requests) {
> + if (ee->num_requests) {
>   err_printf(m, "%s --- %d requests\n",
>      dev_priv->engine[i].name,
> -    error->ring[i].num_requests);
> - for (j = 0; j < error->ring[i].num_requests; j++) {
> +    ee->num_requests);
> + for (j = 0; j < ee->num_requests; j++) {
>   err_printf(m, "  seqno 0x%08x, emitted %ld, tail 0x%08x\n",
> -    error->ring[i].requests[j].seqno,
> -    error->ring[i].requests[j].jiffies,
> -    error->ring[i].requests[j].tail);
> +    ee->requests[j].seqno,
> +    ee->requests[j].jiffies,
> +    ee->requests[j].tail);
>   }
>   }
>
> - if (error->ring[i].num_waiters) {
> + if (ee->num_waiters) {
>   err_printf(m, "%s --- %d waiters\n",
>      dev_priv->engine[i].name,
> -    error->ring[i].num_waiters);
> - for (j = 0; j < error->ring[i].num_waiters; j++) {
> +    ee->num_waiters);
> + for (j = 0; j < ee->num_waiters; j++) {
>   err_printf(m, " seqno 0x%08x for %s [%d]\n",
> -    error->ring[i].waiters[j].seqno,
> -    error->ring[i].waiters[j].comm,
> -    error->ring[i].waiters[j].pid);
> +    ee->waiters[j].seqno,
> +    ee->waiters[j].comm,
> +    ee->waiters[j].pid);
>   }
>   }
>
> - if ((obj = error->ring[i].ringbuffer)) {
> + 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 = error->ring[i].hws_page)) {
> + if ((obj = ee->hws_page)) {
>   u64 hws_offset = obj->gtt_offset;
>   u32 *hws_page = &obj->pages[0][0];
>
> @@ -504,7 +503,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>   }
>   }
>
> - obj = error->ring[i].wa_ctx;
> + obj = ee->wa_ctx;
>   if (obj) {
>   u64 wa_ctx_offset = obj->gtt_offset;
>   u32 *wa_ctx_page = &obj->pages[0][0];
> @@ -526,7 +525,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
>   }
>   }
>
> - if ((obj = error->ring[i].ctx)) {
> + if ((obj = ee->ctx)) {
>   err_printf(m, "%s --- HW Context = 0x%08x\n",
>      dev_priv->engine[i].name,
>      lower_32_bits(obj->gtt_offset));
> @@ -611,15 +610,18 @@ static void i915_error_state_free(struct kref *error_ref)
>     typeof(*error), ref);
>   int i;
>
> - for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
> - i915_error_object_free(error->ring[i].batchbuffer);
> - i915_error_object_free(error->ring[i].wa_batchbuffer);
> - i915_error_object_free(error->ring[i].ringbuffer);
> - i915_error_object_free(error->ring[i].hws_page);
> - i915_error_object_free(error->ring[i].ctx);
> - i915_error_object_free(error->ring[i].wa_ctx);
> - kfree(error->ring[i].requests);
> - kfree(error->ring[i].waiters);
> + 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);
> + kfree(ee->waiters);
>   }
>
>   i915_error_object_free(error->semaphore_obj);
> @@ -762,8 +764,8 @@ static void capture_bo(struct drm_i915_error_buffer *err,
>   err->dirty = obj->dirty;
>   err->purgeable = obj->madv != I915_MADV_WILLNEED;
>   err->userptr = obj->userptr.mm != NULL;
> - err->ring = obj->last_write_req ?
> - i915_gem_request_get_engine(obj->last_write_req)->id : -1;
> + err->engine = obj->last_write_req ?
> + i915_gem_request_get_engine(obj->last_write_req)->id : -1;
>   err->cache_level = obj->cache_level;
>  }
>
> @@ -815,7 +817,7 @@ static u32 capture_pinned_bo(struct drm_i915_error_buffer *err,
>   */
>  static uint32_t i915_error_generate_code(struct drm_i915_private *dev_priv,
>    struct drm_i915_error_state *error,
> -  int *ring_id)
> +  int *engine_id)
>  {
>   uint32_t error_code = 0;
>   int i;
> @@ -826,11 +828,11 @@ static uint32_t i915_error_generate_code(struct drm_i915_private *dev_priv,
>    * strictly a client bug. Use instdone to differentiate those some.
>    */
>   for (i = 0; i < I915_NUM_ENGINES; i++) {
> - if (error->ring[i].hangcheck_action == HANGCHECK_HUNG) {
> - if (ring_id)
> - *ring_id = i;
> + if (error->engine[i].hangcheck_action == HANGCHECK_HUNG) {
> + if (engine_id)
> + *engine_id = i;
>
> - return error->ring[i].ipehr ^ error->ring[i].instdone;
> + return error->engine[i].ipehr ^ error->engine[i].instdone;
>   }
>   }
>
> @@ -855,21 +857,16 @@ static void i915_gem_record_fences(struct drm_i915_private *dev_priv,
>  }
>
>
> -static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
> - struct drm_i915_error_state *error,
> +static void gen8_record_semaphore_state(struct drm_i915_error_state *error,
>   struct intel_engine_cs *engine,
> - struct drm_i915_error_ring *ering)
> + 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 (!i915.semaphores)
> - return;
> -
>   if (!error->semaphore_obj)
> - error->semaphore_obj =
> - i915_error_ggtt_object_create(dev_priv,
> -       dev_priv->semaphore_obj);
> + return;
>
>   for_each_engine_id(to, dev_priv, id) {
>   int idx;
> @@ -879,42 +876,43 @@ static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
>   if (engine == to)
>   continue;
>
> - signal_offset = (GEN8_SIGNAL_OFFSET(engine, id) & (PAGE_SIZE - 1))
> - / 4;
> + signal_offset =
> + (GEN8_SIGNAL_OFFSET(engine, id) & (PAGE_SIZE - 1)) / 4;
>   tmp = error->semaphore_obj->pages[0];
>   idx = intel_ring_sync_index(engine, to);
>
> - ering->semaphore_mboxes[idx] = tmp[signal_offset];
> - ering->semaphore_seqno[idx] = engine->semaphore.sync_seqno[idx];
> + ee->semaphore_mboxes[idx] = tmp[signal_offset];
> + ee->semaphore_seqno[idx] = engine->semaphore.sync_seqno[idx];
>   }
>  }
>
> -static void gen6_record_semaphore_state(struct drm_i915_private *dev_priv,
> - struct intel_engine_cs *engine,
> - struct drm_i915_error_ring *ering)
> +static void gen6_record_semaphore_state(struct intel_engine_cs *engine,
> + struct drm_i915_error_engine *ee)
>  {
> - ering->semaphore_mboxes[0] = I915_READ(RING_SYNC_0(engine->mmio_base));
> - ering->semaphore_mboxes[1] = I915_READ(RING_SYNC_1(engine->mmio_base));
> - ering->semaphore_seqno[0] = engine->semaphore.sync_seqno[0];
> - ering->semaphore_seqno[1] = engine->semaphore.sync_seqno[1];
> + 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)) {
> - ering->semaphore_mboxes[2] =
> + ee->semaphore_mboxes[2] =
>   I915_READ(RING_SYNC_2(engine->mmio_base));
> - ering->semaphore_seqno[2] = engine->semaphore.sync_seqno[2];
> + ee->semaphore_seqno[2] = engine->semaphore.sync_seqno[2];
>   }
>  }
>
> -static void engine_record_waiters(struct intel_engine_cs *engine,
> -   struct drm_i915_error_ring *ering)
> +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;
>
> - ering->num_waiters = 0;
> - ering->waiters = NULL;
> + ee->num_waiters = 0;
> + ee->waiters = NULL;
>
>   spin_lock(&b->lock);
>   count = 0;
> @@ -930,7 +928,7 @@ static void engine_record_waiters(struct intel_engine_cs *engine,
>   if (!waiter)
>   return;
>
> - ering->waiters = waiter;
> + ee->waiters = waiter;
>
>   spin_lock(&b->lock);
>   for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
> @@ -941,55 +939,55 @@ static void engine_record_waiters(struct intel_engine_cs *engine,
>   waiter->seqno = w->seqno;
>   waiter++;
>
> - if (++ering->num_waiters == count)
> + if (++ee->num_waiters == count)
>   break;
>   }
>   spin_unlock(&b->lock);
>  }
>
> -static void i915_record_ring_state(struct drm_i915_private *dev_priv,
> -    struct drm_i915_error_state *error,
> -    struct intel_engine_cs *engine,
> -    struct drm_i915_error_ring *ering)
> +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) {
> - ering->rc_psmi = I915_READ(RING_PSMI_CTL(engine->mmio_base));
> - ering->fault_reg = I915_READ(RING_FAULT_REG(engine));
> + 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(dev_priv, error, engine,
> -     ering);
> + gen8_record_semaphore_state(error, engine, ee);
>   else
> - gen6_record_semaphore_state(dev_priv, engine, ering);
> + gen6_record_semaphore_state(engine, ee);
>   }
>
>   if (INTEL_GEN(dev_priv) >= 4) {
> - ering->faddr = I915_READ(RING_DMA_FADD(engine->mmio_base));
> - ering->ipeir = I915_READ(RING_IPEIR(engine->mmio_base));
> - ering->ipehr = I915_READ(RING_IPEHR(engine->mmio_base));
> - ering->instdone = I915_READ(RING_INSTDONE(engine->mmio_base));
> - ering->instps = I915_READ(RING_INSTPS(engine->mmio_base));
> - ering->bbaddr = I915_READ(RING_BBADDR(engine->mmio_base));
> + 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->instdone = I915_READ(RING_INSTDONE(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) {
> - ering->faddr |= (u64) I915_READ(RING_DMA_FADD_UDW(engine->mmio_base)) << 32;
> - ering->bbaddr |= (u64) I915_READ(RING_BBADDR_UDW(engine->mmio_base)) << 32;
> + 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;
>   }
> - ering->bbstate = I915_READ(RING_BBSTATE(engine->mmio_base));
> + ee->bbstate = I915_READ(RING_BBSTATE(engine->mmio_base));
>   } else {
> - ering->faddr = I915_READ(DMA_FADD_I8XX);
> - ering->ipeir = I915_READ(IPEIR);
> - ering->ipehr = I915_READ(IPEHR);
> - ering->instdone = I915_READ(GEN2_INSTDONE);
> + ee->faddr = I915_READ(DMA_FADD_I8XX);
> + ee->ipeir = I915_READ(IPEIR);
> + ee->ipehr = I915_READ(IPEHR);
> + ee->instdone = I915_READ(GEN2_INSTDONE);
>   }
>
> - ering->waiting = intel_engine_has_waiter(engine);
> - ering->instpm = I915_READ(RING_INSTPM(engine->mmio_base));
> - ering->acthd = intel_ring_get_active_head(engine);
> - ering->seqno = intel_engine_get_seqno(engine);
> - ering->last_seqno = engine->last_submitted_seqno;
> - ering->start = I915_READ_START(engine);
> - ering->head = I915_READ_HEAD(engine);
> - ering->tail = I915_READ_TAIL(engine);
> - ering->ctl = I915_READ_CTL(engine);
> + ee->waiting = intel_engine_has_waiter(engine);
> + ee->instpm = I915_READ(RING_INSTPM(engine->mmio_base));
> + ee->acthd = intel_ring_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 (I915_NEED_GFX_HWS(dev_priv)) {
>   i915_reg_t mmio;
> @@ -1017,29 +1015,29 @@ static void i915_record_ring_state(struct drm_i915_private *dev_priv,
>   mmio = RING_HWS_PGA(engine->mmio_base);
>   }
>
> - ering->hws = I915_READ(mmio);
> + ee->hws = I915_READ(mmio);
>   }
>
> - ering->hangcheck_score = engine->hangcheck.score;
> - ering->hangcheck_action = engine->hangcheck.action;
> + ee->hangcheck_score = engine->hangcheck.score;
> + ee->hangcheck_action = engine->hangcheck.action;
>
>   if (USES_PPGTT(dev_priv)) {
>   int i;
>
> - ering->vm_info.gfx_mode = I915_READ(RING_MODE_GEN7(engine));
> + ee->vm_info.gfx_mode = I915_READ(RING_MODE_GEN7(engine));
>
>   if (IS_GEN6(dev_priv))
> - ering->vm_info.pp_dir_base =
> + ee->vm_info.pp_dir_base =
>   I915_READ(RING_PP_DIR_BASE_READ(engine));
>   else if (IS_GEN7(dev_priv))
> - ering->vm_info.pp_dir_base =
> + 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++) {
> - ering->vm_info.pdp[i] =
> + ee->vm_info.pdp[i] =
>   I915_READ(GEN8_RING_PDP_UDW(engine, i));
> - ering->vm_info.pdp[i] <<= 32;
> - ering->vm_info.pdp[i] |=
> + ee->vm_info.pdp[i] <<= 32;
> + ee->vm_info.pdp[i] |=
>   I915_READ(GEN8_RING_PDP_LDW(engine, i));
>   }
>   }
> @@ -1048,7 +1046,7 @@ static void i915_record_ring_state(struct drm_i915_private *dev_priv,
>
>  static void i915_gem_record_active_context(struct intel_engine_cs *engine,
>      struct drm_i915_error_state *error,
> -    struct drm_i915_error_ring *ering)
> +    struct drm_i915_error_engine *ee)
>  {
>   struct drm_i915_private *dev_priv = engine->i915;
>   struct drm_i915_gem_object *obj;
> @@ -1062,7 +1060,7 @@ static void i915_gem_record_active_context(struct intel_engine_cs *engine,
>   continue;
>
>   if ((error->ccid & PAGE_MASK) == i915_gem_obj_ggtt_offset(obj)) {
> - ering->ctx = i915_error_ggtt_object_create(dev_priv, obj);
> + ee->ctx = i915_error_ggtt_object_create(dev_priv, obj);
>   break;
>   }
>   }
> @@ -1075,18 +1073,26 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
>   struct drm_i915_gem_request *request;
>   int i, count;
>
> + if (dev_priv->semaphore_obj) {
> + error->semaphore_obj =
> + i915_error_ggtt_object_create(dev_priv,
> +       dev_priv->semaphore_obj);
> + }
> +
>   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];
>
> - error->ring[i].pid = -1;
> + ee->pid = -1;
> + ee->engine_id = -1;
>
>   if (!intel_engine_initialized(engine))
>   continue;
>
> - error->ring[i].valid = true;
> + ee->engine_id = i;
>
> - i915_record_ring_state(dev_priv, error, engine, &error->ring[i]);
> - engine_record_waiters(engine, &error->ring[i]);
> + error_record_engine_registers(error, engine, ee);
> + error_record_engine_waiters(engine, ee);
>
>   request = i915_gem_find_active_request(engine);
>   if (request) {
> @@ -1100,13 +1106,13 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
>    * as the simplest method to avoid being overwritten
>    * by userspace.
>    */
> - error->ring[i].batchbuffer =
> + ee->batchbuffer =
>   i915_error_object_create(dev_priv,
>    request->batch_obj,
>    vm);
>
>   if (HAS_BROKEN_CS_TLB(dev_priv))
> - error->ring[i].wa_batchbuffer =
> + ee->wa_batchbuffer =
>   i915_error_ggtt_object_create(dev_priv,
>        engine->scratch.obj);
>
> @@ -1116,8 +1122,8 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
>   rcu_read_lock();
>   task = pid_task(request->pid, PIDTYPE_PID);
>   if (task) {
> - strcpy(error->ring[i].comm, task->comm);
> - error->ring[i].pid = task->pid;
> + strcpy(ee->comm, task->comm);
> + ee->pid = task->pid;
>   }
>   rcu_read_unlock();
>   }
> @@ -1126,35 +1132,34 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
>   request->ctx->flags & CONTEXT_NO_ERROR_CAPTURE;
>
>   rb = request->ringbuf;
> - error->ring[i].cpu_ring_head = rb->head;
> - error->ring[i].cpu_ring_tail = rb->tail;
> - error->ring[i].ringbuffer =
> + ee->cpu_ring_head = rb->head;
> + ee->cpu_ring_tail = rb->tail;
> + ee->ringbuffer =
>   i915_error_ggtt_object_create(dev_priv,
>         rb->obj);
>   }
>
> - error->ring[i].hws_page =
> + ee->hws_page =
>   i915_error_ggtt_object_create(dev_priv,
>         engine->status_page.obj);
>
>   if (engine->wa_ctx.obj) {
> - error->ring[i].wa_ctx =
> + ee->wa_ctx =
>   i915_error_ggtt_object_create(dev_priv,
>         engine->wa_ctx.obj);
>   }
>
> - i915_gem_record_active_context(engine, error, &error->ring[i]);
> + i915_gem_record_active_context(engine, error, ee);
>
>   count = 0;
>   list_for_each_entry(request, &engine->request_list, list)
>   count++;
>
> - error->ring[i].num_requests = count;
> - error->ring[i].requests =
> - kcalloc(count, sizeof(*error->ring[i].requests),
> - GFP_ATOMIC);
> - if (error->ring[i].requests == NULL) {
> - error->ring[i].num_requests = 0;
> + ee->num_requests = count;
> + ee->requests =
> + kcalloc(count, sizeof(*ee->requests), GFP_ATOMIC);
> + if (!ee->requests) {
> + ee->num_requests = 0;
>   continue;
>   }
>
> @@ -1162,7 +1167,7 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
>   list_for_each_entry(request, &engine->request_list, list) {
>   struct drm_i915_error_request *erq;
>
> - if (count >= error->ring[i].num_requests) {
> + if (count >= ee->num_requests) {
>   /*
>    * If the ring request list was changed in
>    * between the point where the error request
> @@ -1181,7 +1186,7 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
>   break;
>   }
>
> - erq = &error->ring[i].requests[count++];
> + erq = &ee->requests[count++];
>   erq->seqno = request->fence.seqno;
>   erq->jiffies = request->emitted_jiffies;
>   erq->tail = request->postfix;
> @@ -1352,20 +1357,20 @@ static void i915_error_capture_msg(struct drm_i915_private *dev_priv,
>      const char *error_msg)
>  {
>   u32 ecode;
> - int ring_id = -1, len;
> + int engine_id = -1, len;
>
> - ecode = i915_error_generate_code(dev_priv, error, &ring_id);
> + 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), ring_id, ecode);
> + INTEL_GEN(dev_priv), engine_id, ecode);
>
> - if (ring_id != -1 && error->ring[ring_id].pid != -1)
> + 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->ring[ring_id].comm,
> -  error->ring[ring_id].pid);
> +  error->engine[engine_id].comm,
> +  error->engine[engine_id].pid);
>
>   scnprintf(error->error_msg + len, sizeof(error->error_msg) - len,
>     ", reason: %s, action: %s",
--
Joonas Lahtinen
Open Source Technology Center
Intel Corporation