diff options
author | Rob Clark <robdclark@chromium.org> | 2023-03-20 17:43:26 +0300 |
---|---|---|
committer | Rob Clark <robdclark@chromium.org> | 2023-03-26 02:31:44 +0300 |
commit | b14b8c5f0eaf363e33c5410c96a6259dee6bd78e (patch) | |
tree | 427296db2846db1d53cfafa590d3dd94935c3027 /drivers/gpu | |
parent | fc2f07566a2cb198eb5902684163e7c4f5309619 (diff) | |
download | linux-b14b8c5f0eaf363e33c5410c96a6259dee6bd78e.tar.xz |
drm/msm: Decouple vma tracking from obj lock
We need to use the inuse count to track that a BO is pinned until
we have the hw_fence. But we want to remove the obj lock from the
job_run() path as this could deadlock against reclaim/shrinker
(because it is blocking the hw_fence from eventually being signaled).
So split that tracking out into a per-vma lock with narrower scope.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/527839/
Link: https://lore.kernel.org/r/20230320144356.803762-5-robdclark@gmail.com
Diffstat (limited to 'drivers/gpu')
-rw-r--r-- | drivers/gpu/drm/msm/msm_gem.h | 1 | ||||
-rw-r--r-- | drivers/gpu/drm/msm/msm_gem_vma.c | 44 | ||||
-rw-r--r-- | drivers/gpu/drm/msm/msm_ringbuffer.c | 2 |
3 files changed, 40 insertions, 7 deletions
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h index d3219c523034..1929f09c5b0d 100644 --- a/drivers/gpu/drm/msm/msm_gem.h +++ b/drivers/gpu/drm/msm/msm_gem.h @@ -59,6 +59,7 @@ struct msm_fence_context; struct msm_gem_vma { struct drm_mm_node node; + spinlock_t lock; uint64_t iova; struct msm_gem_address_space *aspace; struct list_head list; /* node in msm_gem_object::vmas */ diff --git a/drivers/gpu/drm/msm/msm_gem_vma.c b/drivers/gpu/drm/msm/msm_gem_vma.c index 2827679dc39a..98287ed99960 100644 --- a/drivers/gpu/drm/msm/msm_gem_vma.c +++ b/drivers/gpu/drm/msm/msm_gem_vma.c @@ -40,19 +40,28 @@ msm_gem_address_space_get(struct msm_gem_address_space *aspace) bool msm_gem_vma_inuse(struct msm_gem_vma *vma) { + bool ret = true; + + spin_lock(&vma->lock); + if (vma->inuse > 0) - return true; + goto out; while (vma->fence_mask) { unsigned idx = ffs(vma->fence_mask) - 1; if (!msm_fence_completed(vma->fctx[idx], vma->fence[idx])) - return true; + goto out; vma->fence_mask &= ~BIT(idx); } - return false; + ret = false; + +out: + spin_unlock(&vma->lock); + + return ret; } /* Actually unmap memory for the vma */ @@ -73,8 +82,7 @@ void msm_gem_vma_purge(struct msm_gem_vma *vma) vma->mapped = false; } -/* Remove reference counts for the mapping */ -void msm_gem_vma_unpin(struct msm_gem_vma *vma) +static void vma_unpin_locked(struct msm_gem_vma *vma) { if (GEM_WARN_ON(!vma->inuse)) return; @@ -82,13 +90,23 @@ void msm_gem_vma_unpin(struct msm_gem_vma *vma) vma->inuse--; } +/* Remove reference counts for the mapping */ +void msm_gem_vma_unpin(struct msm_gem_vma *vma) +{ + spin_lock(&vma->lock); + vma_unpin_locked(vma); + spin_unlock(&vma->lock); +} + /* Replace pin reference with fence: */ void msm_gem_vma_unpin_fenced(struct msm_gem_vma *vma, struct msm_fence_context *fctx) { + spin_lock(&vma->lock); vma->fctx[fctx->index] = fctx; vma->fence[fctx->index] = fctx->last_fence; vma->fence_mask |= BIT(fctx->index); - msm_gem_vma_unpin(vma); + vma_unpin_locked(vma); + spin_unlock(&vma->lock); } /* Map and pin vma: */ @@ -103,7 +121,9 @@ msm_gem_vma_map(struct msm_gem_vma *vma, int prot, return -EINVAL; /* Increase the usage counter */ + spin_lock(&vma->lock); vma->inuse++; + spin_unlock(&vma->lock); if (vma->mapped) return 0; @@ -113,11 +133,22 @@ msm_gem_vma_map(struct msm_gem_vma *vma, int prot, if (!aspace) return 0; + /* + * NOTE: iommu/io-pgtable can allocate pages, so we cannot hold + * a lock across map/unmap which is also used in the job_run() + * path, as this can cause deadlock in job_run() vs shrinker/ + * reclaim. + * + * Revisit this if we can come up with a scheme to pre-alloc pages + * for the pgtable in map/unmap ops. + */ ret = aspace->mmu->funcs->map(aspace->mmu, vma->iova, sgt, size, prot); if (ret) { vma->mapped = false; + spin_lock(&vma->lock); vma->inuse--; + spin_unlock(&vma->lock); } return ret; @@ -148,6 +179,7 @@ struct msm_gem_vma *msm_gem_vma_new(struct msm_gem_address_space *aspace) if (!vma) return NULL; + spin_lock_init(&vma->lock); vma->aspace = aspace; return vma; diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c index 44a22b283730..31b4fbf96c36 100644 --- a/drivers/gpu/drm/msm/msm_ringbuffer.c +++ b/drivers/gpu/drm/msm/msm_ringbuffer.c @@ -23,8 +23,8 @@ static struct dma_fence *msm_job_run(struct drm_sched_job *job) for (i = 0; i < submit->nr_bos; i++) { struct drm_gem_object *obj = &submit->bos[i].obj->base; - msm_gem_lock(obj); msm_gem_vma_unpin_fenced(submit->bos[i].vma, fctx); + msm_gem_lock(obj); msm_gem_unpin_locked(obj); msm_gem_unlock(obj); submit->bos[i].flags &= ~(BO_VMA_PINNED | BO_OBJ_PINNED); |