Rings need to lock in order, otherwise the ring subsystem can deadlock.
v2: fix error handling and number of locked doublewords. v3: stop creating unneeded semaphores.
Signed-off-by: Christian König deathsimple@vodafone.de Reviewed-by: Jerome Glisse jglisse@redhat.com --- drivers/gpu/drm/radeon/radeon.h | 4 ++ drivers/gpu/drm/radeon/radeon_cs.c | 35 ++++++------------ drivers/gpu/drm/radeon/radeon_semaphore.c | 56 +++++++++++++++++++++++++++++ drivers/gpu/drm/radeon/radeon_ttm.c | 46 ++++++++++------------- 4 files changed, 92 insertions(+), 49 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h index 794182a..f7372c4 100644 --- a/drivers/gpu/drm/radeon/radeon.h +++ b/drivers/gpu/drm/radeon/radeon.h @@ -460,6 +460,10 @@ void radeon_semaphore_emit_signal(struct radeon_device *rdev, int ring, struct radeon_semaphore *semaphore); void radeon_semaphore_emit_wait(struct radeon_device *rdev, int ring, struct radeon_semaphore *semaphore); +int radeon_semaphore_sync_rings(struct radeon_device *rdev, + struct radeon_semaphore *semaphore, + bool sync_to[RADEON_NUM_RINGS], + int dst_ring); void radeon_semaphore_free(struct radeon_device *rdev, struct radeon_semaphore *semaphore);
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c index e7b0b5d..24fb001 100644 --- a/drivers/gpu/drm/radeon/radeon_cs.c +++ b/drivers/gpu/drm/radeon/radeon_cs.c @@ -118,6 +118,7 @@ static int radeon_cs_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority static int radeon_cs_sync_rings(struct radeon_cs_parser *p) { bool sync_to_ring[RADEON_NUM_RINGS] = { }; + bool need_sync = false; int i, r;
for (i = 0; i < p->nrelocs; i++) { @@ -126,36 +127,24 @@ static int radeon_cs_sync_rings(struct radeon_cs_parser *p)
if (!(p->relocs[i].flags & RADEON_RELOC_DONT_SYNC)) { struct radeon_fence *fence = p->relocs[i].robj->tbo.sync_obj; - if (!radeon_fence_signaled(fence)) { + if (fence->ring != p->ring && !radeon_fence_signaled(fence)) { sync_to_ring[fence->ring] = true; + need_sync = true; } } }
- for (i = 0; i < RADEON_NUM_RINGS; ++i) { - /* no need to sync to our own or unused rings */ - if (i == p->ring || !sync_to_ring[i] || !p->rdev->ring[i].ready) - continue; - - if (!p->ib->fence->semaphore) { - r = radeon_semaphore_create(p->rdev, &p->ib->fence->semaphore); - if (r) - return r; - } - - r = radeon_ring_lock(p->rdev, &p->rdev->ring[i], 3); - if (r) - return r; - radeon_semaphore_emit_signal(p->rdev, i, p->ib->fence->semaphore); - radeon_ring_unlock_commit(p->rdev, &p->rdev->ring[i]); + if (!need_sync) { + return 0; + }
- r = radeon_ring_lock(p->rdev, &p->rdev->ring[p->ring], 3); - if (r) - return r; - radeon_semaphore_emit_wait(p->rdev, p->ring, p->ib->fence->semaphore); - radeon_ring_unlock_commit(p->rdev, &p->rdev->ring[p->ring]); + r = radeon_semaphore_create(p->rdev, &p->ib->fence->semaphore); + if (r) { + return r; } - return 0; + + return radeon_semaphore_sync_rings(p->rdev, p->ib->fence->semaphore, + sync_to_ring, p->ring); }
int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data) diff --git a/drivers/gpu/drm/radeon/radeon_semaphore.c b/drivers/gpu/drm/radeon/radeon_semaphore.c index 61dd4e3..930a08a 100644 --- a/drivers/gpu/drm/radeon/radeon_semaphore.c +++ b/drivers/gpu/drm/radeon/radeon_semaphore.c @@ -149,6 +149,62 @@ void radeon_semaphore_emit_wait(struct radeon_device *rdev, int ring, radeon_semaphore_ring_emit(rdev, ring, &rdev->ring[ring], semaphore, true); }
+int radeon_semaphore_sync_rings(struct radeon_device *rdev, + struct radeon_semaphore *semaphore, + bool sync_to[RADEON_NUM_RINGS], + int dst_ring) +{ + int i, r; + + for (i = 0; i < RADEON_NUM_RINGS; ++i) { + unsigned num_ops = i == dst_ring ? RADEON_NUM_RINGS : 1; + + /* don't lock unused rings */ + if (!sync_to[i] && i != dst_ring) + continue; + + /* prevent GPU deadlocks */ + if (!rdev->ring[i].ready) { + dev_err(rdev->dev, "Trying to sync to a disabled ring!"); + r = -EINVAL; + goto error; + } + + r = radeon_ring_lock(rdev, &rdev->ring[i], num_ops * 8); + if (r) + goto error; + } + + for (i = 0; i < RADEON_NUM_RINGS; ++i) { + /* no need to sync to our own or unused rings */ + if (!sync_to[i] || i == dst_ring) + continue; + + radeon_semaphore_emit_signal(rdev, i, semaphore); + radeon_semaphore_emit_wait(rdev, dst_ring, semaphore); + } + + for (i = 0; i < RADEON_NUM_RINGS; ++i) { + + /* don't unlock unused rings */ + if (!sync_to[i] && i != dst_ring) + continue; + + radeon_ring_unlock_commit(rdev, &rdev->ring[i]); + } + + return 0; + +error: + /* unlock all locks taken so far */ + for (--i; i >= 0; --i) { + if (sync_to[i] || i == dst_ring) { + radeon_ring_unlock_undo(rdev, &rdev->ring[i]); + } + } + return r; +} + void radeon_semaphore_free(struct radeon_device *rdev, struct radeon_semaphore *semaphore) { diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c index f493c64..5e3d54d 100644 --- a/drivers/gpu/drm/radeon/radeon_ttm.c +++ b/drivers/gpu/drm/radeon/radeon_ttm.c @@ -222,8 +222,8 @@ static int radeon_move_blit(struct ttm_buffer_object *bo, { struct radeon_device *rdev; uint64_t old_start, new_start; - struct radeon_fence *fence; - int r, i; + struct radeon_fence *fence, *old_fence; + int r;
rdev = radeon_get_rdev(bo->bdev); r = radeon_fence_create(rdev, &fence, radeon_copy_ring_index(rdev)); @@ -242,6 +242,7 @@ static int radeon_move_blit(struct ttm_buffer_object *bo, break; default: DRM_ERROR("Unknown placement %d\n", old_mem->mem_type); + radeon_fence_unref(&fence); return -EINVAL; } switch (new_mem->mem_type) { @@ -253,42 +254,35 @@ static int radeon_move_blit(struct ttm_buffer_object *bo, break; default: DRM_ERROR("Unknown placement %d\n", old_mem->mem_type); + radeon_fence_unref(&fence); return -EINVAL; } if (!rdev->ring[radeon_copy_ring_index(rdev)].ready) { DRM_ERROR("Trying to move memory with ring turned off.\n"); + radeon_fence_unref(&fence); return -EINVAL; }
BUILD_BUG_ON((PAGE_SIZE % RADEON_GPU_PAGE_SIZE) != 0);
/* sync other rings */ - if (rdev->family >= CHIP_R600) { - for (i = 0; i < RADEON_NUM_RINGS; ++i) { - /* no need to sync to our own or unused rings */ - if (i == radeon_copy_ring_index(rdev) || !rdev->ring[i].ready) - continue; - - if (!fence->semaphore) { - r = radeon_semaphore_create(rdev, &fence->semaphore); - /* FIXME: handle semaphore error */ - if (r) - continue; - } + old_fence = bo->sync_obj; + if (old_fence && old_fence->ring != fence->ring + && !radeon_fence_signaled(old_fence)) { + bool sync_to_ring[RADEON_NUM_RINGS] = { }; + sync_to_ring[old_fence->ring] = true; + + r = radeon_semaphore_create(rdev, &fence->semaphore); + if (r) { + radeon_fence_unref(&fence); + return r; + }
- r = radeon_ring_lock(rdev, &rdev->ring[i], 3); - /* FIXME: handle ring lock error */ - if (r) - continue; - radeon_semaphore_emit_signal(rdev, i, fence->semaphore); - radeon_ring_unlock_commit(rdev, &rdev->ring[i]); - - r = radeon_ring_lock(rdev, &rdev->ring[radeon_copy_ring_index(rdev)], 3); - /* FIXME: handle ring lock error */ - if (r) - continue; - radeon_semaphore_emit_wait(rdev, radeon_copy_ring_index(rdev), fence->semaphore); - radeon_ring_unlock_commit(rdev, &rdev->ring[radeon_copy_ring_index(rdev)]); + r = radeon_semaphore_sync_rings(rdev, fence->semaphore, + sync_to_ring, fence->ring); + if (r) { + radeon_fence_unref(&fence); + return r; } }