From: Rob Clark robdclark@chromium.org
Now that everything that controls which LRU an obj lives in *except* the backing pages is protected by the LRU lock, add a special path to unpin in the job_run() path, we we are assured that we already have backing pages and will not be racing against eviction (because the GEM object's dma_resv contains the fence that will be signaled when the submit/job completes).
Signed-off-by: Rob Clark robdclark@chromium.org --- drivers/gpu/drm/msm/msm_gem.c | 44 +++++++++++++++++++++++----- drivers/gpu/drm/msm/msm_gem.h | 1 + drivers/gpu/drm/msm/msm_ringbuffer.c | 4 +-- 3 files changed, 39 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index d0ac3e704b66..9628e8d8dd02 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -61,18 +61,14 @@ static void sync_for_cpu(struct msm_gem_object *msm_obj) dma_unmap_sgtable(dev, msm_obj->sgt, DMA_BIDIRECTIONAL, 0); }
-static void update_lru_locked(struct drm_gem_object *obj) +static void update_lru_active(struct drm_gem_object *obj) { struct msm_drm_private *priv = obj->dev->dev_private; struct msm_gem_object *msm_obj = to_msm_bo(obj);
- msm_gem_assert_locked(&msm_obj->base); - - if (!msm_obj->pages) { - GEM_WARN_ON(msm_obj->pin_count); + GEM_WARN_ON(!msm_obj->pages);
- drm_gem_lru_move_tail_locked(&priv->lru.unbacked, obj); - } else if (msm_obj->pin_count) { + if (msm_obj->pin_count) { drm_gem_lru_move_tail_locked(&priv->lru.pinned, obj); } else if (msm_obj->madv == MSM_MADV_WILLNEED) { drm_gem_lru_move_tail_locked(&priv->lru.willneed, obj); @@ -83,6 +79,22 @@ static void update_lru_locked(struct drm_gem_object *obj) } }
+static void update_lru_locked(struct drm_gem_object *obj) +{ + struct msm_drm_private *priv = obj->dev->dev_private; + struct msm_gem_object *msm_obj = to_msm_bo(obj); + + msm_gem_assert_locked(&msm_obj->base); + + if (!msm_obj->pages) { + GEM_WARN_ON(msm_obj->pin_count); + + drm_gem_lru_move_tail_locked(&priv->lru.unbacked, obj); + } else { + update_lru_active(obj); + } +} + static void update_lru(struct drm_gem_object *obj) { struct msm_drm_private *priv = obj->dev->dev_private; @@ -489,6 +501,24 @@ void msm_gem_unpin_locked(struct drm_gem_object *obj) mutex_unlock(&priv->lru.lock); }
+/* Special unpin path for use in fence-signaling path, avoiding the need + * to hold the obj lock by only depending on things that a protected by + * the LRU lock. In particular we know that that we already have backing + * and and that the object's dma_resv has the fence for the current + * submit/job which will prevent us racing against page eviction. + */ +void msm_gem_unpin_active(struct drm_gem_object *obj) +{ + struct msm_drm_private *priv = obj->dev->dev_private; + struct msm_gem_object *msm_obj = to_msm_bo(obj); + + mutex_lock(&priv->lru.lock); + msm_obj->pin_count--; + GEM_WARN_ON(msm_obj->pin_count < 0); + update_lru_active(obj); + mutex_unlock(&priv->lru.lock); +} + struct msm_gem_vma *msm_gem_get_vma_locked(struct drm_gem_object *obj, struct msm_gem_address_space *aspace) { diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index 0057e8e8fa13..2bd6846c83a9 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -128,6 +128,7 @@ struct msm_gem_object { uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj); int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct msm_gem_vma *vma); void msm_gem_unpin_locked(struct drm_gem_object *obj); +void msm_gem_unpin_active(struct drm_gem_object *obj); struct msm_gem_vma *msm_gem_get_vma_locked(struct drm_gem_object *obj, struct msm_gem_address_space *aspace); int msm_gem_get_iova(struct drm_gem_object *obj, diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c index 31b4fbf96c36..b60199184409 100644 --- a/drivers/gpu/drm/msm/msm_ringbuffer.c +++ b/drivers/gpu/drm/msm/msm_ringbuffer.c @@ -24,9 +24,7 @@ static struct dma_fence *msm_job_run(struct drm_sched_job *job) struct drm_gem_object *obj = &submit->bos[i].obj->base;
msm_gem_vma_unpin_fenced(submit->bos[i].vma, fctx); - msm_gem_lock(obj); - msm_gem_unpin_locked(obj); - msm_gem_unlock(obj); + msm_gem_unpin_active(obj); submit->bos[i].flags &= ~(BO_VMA_PINNED | BO_OBJ_PINNED); }