Re: [PATCH 10/13] drm/i915/bdw: collect semaphore error state

Ville Syrjälä
2014-02-24T13:08:08Z

On Wed, Feb 19, 2014 at 10:19:23PM -0800, Ben Widawsky wrote:
> Since the semaphore information is in an object, just dump it, and let
> the user parse it later.
>
> NOTE: The page being used for the semaphores are incoherent with the
> CPU. No matter what I do, I cannot figure out a way to read anything but
> 0s. Note that the semaphore waits are indeed working.
>
> v2: Don't print signal, and wait (they should be the same). Instead,
> print sync_seqno (Chris)
>
> v3: Free the semaphore error object (Chris)
>
> v4: Fix semaphore offset calculation during error state collection
> (Ville)
>
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/i915_gpu_error.c | 52 ++++++++++++++++++++++++++++++---
> drivers/gpu/drm/i915/intel_ringbuffer.h | 12 ++++----
> 3 files changed, 55 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 028ce5a..9b86874 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -322,6 +322,7 @@ struct drm_i915_error_state {
> u64 fence[I915_MAX_NUM_FENCES];
> struct intel_overlay_error_state *overlay;
> struct intel_display_error_state *display;
> + struct drm_i915_error_object *semaphore_obj;
>
> struct drm_i915_error_ring {
> bool valid;
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index 2b64493..25fc2ea 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -310,6 +310,7 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
> struct drm_device *dev = error_priv->dev;
> drm_i915_private_t *dev_priv = dev->dev_private;
> struct drm_i915_error_state *error = error_priv->error;
> + struct drm_i915_error_object *obj;
> int i, j, page, offset, elt;
>
> if (!error) {
> @@ -360,8 +361,6 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
> error->pinned_bo_count[0]);
>
> for (i = 0; i < ARRAY_SIZE(error->ring); i++) {
> - struct drm_i915_error_object *obj;
> -
> if ((obj = error->ring[i].batchbuffer)) {
> err_printf(m, "%s --- gtt_offset = 0x%08x\n",
> dev_priv->ring[i].name,
> @@ -436,6 +435,19 @@ int i915_error_state_to_str(struct drm_i915_error_state_buf *m,
> }
> }
>
> + obj = error->semaphore_obj;
> + if (obj) {

Still won't pass under Chris's consitency radar.

> + err_printf(m, "Semaphore page = 0x%08x\n", 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);
>
> @@ -506,6 +518,7 @@ static void i915_error_state_free(struct kref *error_ref)
> kfree(error->ring[i].requests);
> }
>
> + i915_error_object_free(error->semaphore_obj);
> kfree(error->active_bo);
> kfree(error->overlay);
> kfree(error->display);
> @@ -797,6 +810,33 @@ i915_error_first_batchbuffer(struct drm_i915_private *dev_priv,
> return NULL;
> }
>
> +static void gen8_record_semaphore_state(struct drm_i915_private *dev_priv,
> + struct drm_i915_error_state *error,
> + struct intel_ring_buffer *ring,
> + struct drm_i915_error_ring *ering)
> +{
> + struct intel_ring_buffer *useless;
> + int i;
> +
> + if (!i915_semaphore_is_enabled(dev_priv->dev))
> + return;
> +
> + if (!error->semaphore_obj)
> + error->semaphore_obj =
> + i915_error_object_create(dev_priv,
> + dev_priv->semaphore_obj,
> + &dev_priv->gtt.base);
> +
> + for_each_ring(useless, dev_priv, i) {
> + u16 signal_offset =
> + (GEN8_SIGNAL_OFFSET(ring, i) / 4) & PAGE_MASK;

(... & PAGE_MASK) / 4;

> + u32 *tmp = error->semaphore_obj->pages[0];
> +
> + ering->semaphore_mboxes[i] = tmp[signal_offset];
> + ering->semaphore_seqno[i] = ring->semaphore.sync_seqno[i];
> + }
> +}
> +
> static void gen6_record_semaphore_state(struct drm_i915_private *dev_priv,
> struct intel_ring_buffer *ring,
> struct drm_i915_error_ring *ering)
> @@ -814,6 +854,7 @@ static void gen6_record_semaphore_state(struct drm_i915_private *dev_priv,
> }
>
> static void i915_record_ring_state(struct drm_device *dev,
> + struct drm_i915_error_state *error,
> struct intel_ring_buffer *ring,
> struct drm_i915_error_ring *ering)
> {
> @@ -822,7 +863,10 @@ static void i915_record_ring_state(struct drm_device *dev,
> if (INTEL_INFO(dev)->gen >= 6) {
> ering->rc_psmi = I915_READ(ring->mmio_base + 0x50);
> ering->fault_reg = I915_READ(RING_FAULT_REG(ring));
> - gen6_record_semaphore_state(dev_priv, ring, ering);
> + if (INTEL_INFO(dev)->gen >= 8)
> + gen8_record_semaphore_state(dev_priv, error, ring, ering);
> + else
> + gen6_record_semaphore_state(dev_priv, ring, ering);
> }
>
> if (INTEL_INFO(dev)->gen >= 4) {
> @@ -948,7 +992,7 @@ static void i915_gem_record_rings(struct drm_device *dev,
>
> error->ring[i].valid = true;
>
> - i915_record_ring_state(dev, ring, &error->ring[i]);
> + i915_record_ring_state(dev, error, ring, &error->ring[i]);
>
> error->ring[i].batchbuffer =
> i915_error_first_batchbuffer(dev_priv, ring);
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index 5d56c95..01aad54 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -37,9 +37,9 @@ struct intel_hw_status_page {
> * do the writes, and that must have qw aligned offsets, simply pretend it's 8b.
> */
> #define i915_semaphore_seqno_size sizeof(uint64_t)
> -#define GEN8_SIGNAL_OFFSET(to) \
> +#define GEN8_SIGNAL_OFFSET(__ring, to) \
> (i915_gem_obj_ggtt_offset(dev_priv->semaphore_obj) + \
> - (ring->id * I915_NUM_RINGS * i915_semaphore_seqno_size) + \
> + ((__ring)->id * I915_NUM_RINGS * i915_semaphore_seqno_size) + \
> (i915_semaphore_seqno_size * (to)))
>
> #define GEN8_WAIT_OFFSET(__ring, from) \
> @@ -51,10 +51,10 @@ struct intel_hw_status_page {
> if (!dev_priv->semaphore_obj) { \
> break; \
> } \
> - ring->semaphore.signal_ggtt[RCS] = GEN8_SIGNAL_OFFSET(RCS); \
> - ring->semaphore.signal_ggtt[VCS] = GEN8_SIGNAL_OFFSET(VCS); \
> - ring->semaphore.signal_ggtt[BCS] = GEN8_SIGNAL_OFFSET(BCS); \
> - ring->semaphore.signal_ggtt[VECS] = GEN8_SIGNAL_OFFSET(VECS); \
> + ring->semaphore.signal_ggtt[RCS] = GEN8_SIGNAL_OFFSET(ring, RCS); \
> + ring->semaphore.signal_ggtt[VCS] = GEN8_SIGNAL_OFFSET(ring, VCS); \
> + ring->semaphore.signal_ggtt[BCS] = GEN8_SIGNAL_OFFSET(ring, BCS); \
> + ring->semaphore.signal_ggtt[VECS] = GEN8_SIGNAL_OFFSET(ring, VECS); \
> ring->semaphore.signal_ggtt[ring->id] = MI_SEMAPHORE_SYNC_INVALID; \
> } while(0)
>
> --
> 1.9.0

--
Ville Syrjälä
Intel OTC