The caching of SGT's is actually quite harmful and should probably removed altogether when all drivers are audited.
Start by providing a separate DMA-buf export implementation in amdgpu. This is also a prerequisite of unpinned DMA-buf handling.
v2: fix unintended recursion, remove debugging leftovers v3: split out from unpinned DMA-buf work v4: rebase on top of new no_sgt_cache flag
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 204 ++++++++++++-------- drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h | 1 - drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 1 - drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 5 + 4 files changed, 133 insertions(+), 78 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c index 4711cf1b5bd2..68a071060793 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c @@ -40,22 +40,6 @@ #include <linux/dma-buf.h> #include <linux/dma-fence-array.h>
-/** - * amdgpu_gem_prime_get_sg_table - &drm_driver.gem_prime_get_sg_table - * implementation - * @obj: GEM buffer object (BO) - * - * Returns: - * A scatter/gather table for the pinned pages of the BO's memory. - */ -struct sg_table *amdgpu_gem_prime_get_sg_table(struct drm_gem_object *obj) -{ - struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); - int npages = bo->tbo.num_pages; - - return drm_prime_pages_to_sg(bo->tbo.ttm->pages, npages); -} - /** * amdgpu_gem_prime_vmap - &dma_buf_ops.vmap implementation * @obj: GEM BO @@ -181,92 +165,158 @@ __reservation_object_make_exclusive(struct reservation_object *obj) }
/** - * amdgpu_dma_buf_map_attach - &dma_buf_ops.attach implementation - * @dma_buf: Shared DMA buffer + * amdgpu_dma_buf_attach - &dma_buf_ops.attach implementation + * + * @dmabuf: DMA-buf where we attach to + * @attach: attachment to add + * + * Add the attachment as user to the exported DMA-buf. + */ +static int amdgpu_dma_buf_attach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attach) +{ + struct drm_gem_object *obj = dmabuf->priv; + struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); + struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); + int r; + + if (attach->dev->driver == adev->dev->driver) + return 0; + + /* + * We only create shared fences for internal use, but importers + * of the dmabuf rely on exclusive fences for implicitly + * tracking write hazards. As any of the current fences may + * correspond to a write, we need to convert all existing + * fences on the reservation object into a single exclusive + * fence. + */ + r = __reservation_object_make_exclusive(bo->tbo.resv); + if (r) + return r; + + bo->prime_shared_count++; + return 0; +} + +/** + * amdgpu_dma_buf_detach - &dma_buf_ops.detach implementation + * + * @dmabuf: DMA-buf where we remove the attachment from + * @attach: the attachment to remove + * + * Called when an attachment is removed from the DMA-buf. + */ +static void amdgpu_dma_buf_detach(struct dma_buf *dmabuf, + struct dma_buf_attachment *attach) +{ + struct drm_gem_object *obj = dmabuf->priv; + struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); + struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); + + if (attach->dev->driver != adev->dev->driver && bo->prime_shared_count) + bo->prime_shared_count--; +} + +/** + * amdgpu_dma_buf_pin - &dma_buf_ops.pin implementation + * + * @attach: attachment to pin down + * + * Pin the BO which is backing the DMA-buf so that it can't move any more. + */ +static int amdgpu_dma_buf_pin(struct dma_buf_attachment *attach) +{ + struct drm_gem_object *obj = attach->dmabuf->priv; + struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); + + /* pin buffer into GTT */ + return amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT); +} + +/** + * amdgpu_dma_buf_unpin - &dma_buf_ops.unpin implementation + * + * @attach: attachment to unpin + * + * Unpin a previously pinned BO to make it movable again. + */ +static void amdgpu_dma_buf_unpin(struct dma_buf_attachment *attach) +{ + struct drm_gem_object *obj = attach->dmabuf->priv; + struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); + + amdgpu_bo_unpin(bo); +} + +/** + * amdgpu_dma_buf_map_dma_buf - &dma_buf_ops.map_dma_buf implementation * @attach: DMA-buf attachment + * @dir: DMA direction * * Makes sure that the shared DMA buffer can be accessed by the target device. * For now, simply pins it to the GTT domain, where it should be accessible by * all DMA devices. * * Returns: - * 0 on success or a negative error code on failure. + * sg_table filled with the DMA addresses to use or ERR_PRT with negative error + * code. */ -static int amdgpu_dma_buf_map_attach(struct dma_buf *dma_buf, - struct dma_buf_attachment *attach) +static struct sg_table * +amdgpu_dma_buf_map_dma_buf(struct dma_buf_attachment *attach, + enum dma_data_direction dir) { + struct dma_buf *dma_buf = attach->dmabuf; struct drm_gem_object *obj = dma_buf->priv; struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); - struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); + struct sg_table *sgt; long r;
- r = drm_gem_map_attach(dma_buf, attach); - if (r) - return r; + if (!bo->pin_count) { + /* move buffer into GTT */ + struct ttm_operation_ctx ctx = { false, false };
- r = amdgpu_bo_reserve(bo, false); - if (unlikely(r != 0)) - goto error_detach; - - - if (attach->dev->driver != adev->dev->driver) { - /* - * We only create shared fences for internal use, but importers - * of the dmabuf rely on exclusive fences for implicitly - * tracking write hazards. As any of the current fences may - * correspond to a write, we need to convert all existing - * fences on the reservation object into a single exclusive - * fence. - */ - r = __reservation_object_make_exclusive(bo->tbo.resv); + amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT); + r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx); if (r) - goto error_unreserve; + return ERR_PTR(r); }
- /* pin buffer into GTT */ - r = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT); - if (r) - goto error_unreserve; + sgt = drm_prime_pages_to_sg(bo->tbo.ttm->pages, bo->tbo.num_pages); + if (IS_ERR(sgt)) + return sgt;
- if (attach->dev->driver != adev->dev->driver) - bo->prime_shared_count++; + if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir, + DMA_ATTR_SKIP_CPU_SYNC)) + goto error_free;
-error_unreserve: - amdgpu_bo_unreserve(bo); + return sgt;
-error_detach: - if (r) - drm_gem_map_detach(dma_buf, attach); - return r; +error_free: + sg_free_table(sgt); + kfree(sgt); + return ERR_PTR(-ENOMEM); }
/** - * amdgpu_dma_buf_map_detach - &dma_buf_ops.detach implementation - * @dma_buf: Shared DMA buffer + * amdgpu_gem_unmap_dma_buf - &dma_buf_ops.unmap_dma_buf implementation * @attach: DMA-buf attachment + * @sgt: sg_table to unmap + * @dir: DMA direction * * This is called when a shared DMA buffer no longer needs to be accessible by * another device. For now, simply unpins the buffer from GTT. */ -static void amdgpu_dma_buf_map_detach(struct dma_buf *dma_buf, - struct dma_buf_attachment *attach) +static void amdgpu_dma_buf_unmap_dma_buf(struct dma_buf_attachment *attach, + struct sg_table *sgt, + enum dma_data_direction dir) { - struct drm_gem_object *obj = dma_buf->priv; - struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); - struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev); - int ret = 0; - - ret = amdgpu_bo_reserve(bo, true); - if (unlikely(ret != 0)) - goto error; - - amdgpu_bo_unpin(bo); - if (attach->dev->driver != adev->dev->driver && bo->prime_shared_count) - bo->prime_shared_count--; - amdgpu_bo_unreserve(bo); + if (!sgt) + return;
-error: - drm_gem_map_detach(dma_buf, attach); + dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir); + sg_free_table(sgt); + kfree(sgt); }
/** @@ -324,10 +374,12 @@ static int amdgpu_dma_buf_begin_cpu_access(struct dma_buf *dma_buf, }
const struct dma_buf_ops amdgpu_dmabuf_ops = { - .attach = amdgpu_dma_buf_map_attach, - .detach = amdgpu_dma_buf_map_detach, - .map_dma_buf = drm_gem_map_dma_buf, - .unmap_dma_buf = drm_gem_unmap_dma_buf, + .attach = amdgpu_dma_buf_attach, + .detach = amdgpu_dma_buf_detach, + .pin = amdgpu_dma_buf_pin, + .unpin = amdgpu_dma_buf_unpin, + .map_dma_buf = amdgpu_dma_buf_map_dma_buf, + .unmap_dma_buf = amdgpu_dma_buf_unmap_dma_buf, .release = drm_gem_dmabuf_release, .begin_cpu_access = amdgpu_dma_buf_begin_cpu_access, .mmap = drm_gem_dmabuf_mmap, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h index c7056cbe8685..f1522292814c 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h @@ -25,7 +25,6 @@
#include <drm/drm_gem.h>
-struct sg_table *amdgpu_gem_prime_get_sg_table(struct drm_gem_object *obj); struct drm_gem_object * amdgpu_gem_prime_import_sg_table(struct drm_device *dev, struct dma_buf_attachment *attach, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index a334d3b4944e..70c5cd2d5fb4 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -1321,7 +1321,6 @@ static struct drm_driver kms_driver = { .gem_prime_export = amdgpu_gem_prime_export, .gem_prime_import = amdgpu_gem_prime_import, .gem_prime_res_obj = amdgpu_gem_prime_res_obj, - .gem_prime_get_sg_table = amdgpu_gem_prime_get_sg_table, .gem_prime_import_sg_table = amdgpu_gem_prime_import_sg_table, .gem_prime_vmap = amdgpu_gem_prime_vmap, .gem_prime_vunmap = amdgpu_gem_prime_vunmap, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c index 93b2c5a48a71..d26e2f0b88d2 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c @@ -31,6 +31,7 @@ */ #include <linux/list.h> #include <linux/slab.h> +#include <linux/dma-buf.h> #include <drm/drmP.h> #include <drm/amdgpu_drm.h> #include <drm/drm_cache.h> @@ -1194,6 +1195,10 @@ void amdgpu_bo_move_notify(struct ttm_buffer_object *bo,
amdgpu_bo_kunmap(abo);
+ if (abo->gem_base.dma_buf && !abo->gem_base.import_attach && + bo->mem.mem_type != TTM_PL_SYSTEM) + dma_buf_invalidate_mappings(abo->gem_base.dma_buf); + /* remember the eviction */ if (evict) atomic64_inc(&adev->num_evictions);