[Intel-gfx] [PATCH 5/5] drm/amdgpu: implement amdgpu_gem_prime_move_notify v2

Christian König
2020-02-18T17:17:17Z

Implement the importer side of unpinned DMA-buf handling.

v2: update page tables immediately

Signed-off-by: Christian König <christian.koenig@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 66 ++++++++++++++++++++-
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 6 ++
2 files changed, 71 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index 770baba621b3..48de7624d49c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -453,7 +453,71 @@ amdgpu_dma_buf_create_obj(struct drm_device *dev, struct dma_buf *dma_buf)
return ERR_PTR(ret);
}

+/**
+ * amdgpu_dma_buf_move_notify - &attach.move_notify implementation
+ *
+ * @attach: the DMA-buf attachment
+ *
+ * Invalidate the DMA-buf attachment, making sure that the we re-create the
+ * mapping before the next use.
+ */
+static void
+amdgpu_dma_buf_move_notify(struct dma_buf_attachment *attach)
+{
+ struct drm_gem_object *obj = attach->importer_priv;
+ struct ww_acquire_ctx *ticket = dma_resv_locking_ctx(obj->resv);
+ struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
+ struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
+ struct ttm_operation_ctx ctx = { false, false };
+ struct ttm_placement placement = {};
+ struct amdgpu_vm_bo_base *bo_base;
+ int r;
+
+ if (bo->tbo.mem.mem_type == TTM_PL_SYSTEM)
+ return;
+
+ r = ttm_bo_validate(&bo->tbo, &placement, &ctx);
+ if (r) {
+ DRM_ERROR("Failed to invalidate DMA-buf import (%d))\n", r);
+ return;
+ }
+
+ for (bo_base = bo->vm_bo; bo_base; bo_base = bo_base->next) {
+ struct amdgpu_vm *vm = bo_base->vm;
+ struct dma_resv *resv = vm->root.base.bo->tbo.base.resv;
+
+ if (ticket) {
+ /* When we get an error here it means that somebody
+ * else is holding the VM lock and updating page tables
+ * So we can just continue here.
+ */
+ r = dma_resv_lock(resv, ticket);
+ if (r)
+ continue;
+
+ } else {
+ /* TODO: This is more problematic and we actually need
+ * to allow page tables updates without holding the
+ * lock.
+ */
+ if (!dma_resv_trylock(resv))
+ continue;
+ }
+
+ r = amdgpu_vm_clear_freed(adev, vm, NULL);
+ if (!r)
+ r = amdgpu_vm_handle_moved(adev, vm);
+
+ if (r && r != -EBUSY)
+ DRM_ERROR("Failed to invalidate VM page tables (%d))\n",
+ r);
+
+ dma_resv_unlock(resv);
+ }
+}
+
static const struct dma_buf_attach_ops amdgpu_dma_buf_attach_ops = {
+ .move_notify = amdgpu_dma_buf_move_notify
};

/**
@@ -489,7 +553,7 @@ struct drm_gem_object *amdgpu_gem_prime_import(struct drm_device *dev,
return obj;

attach = dma_buf_dynamic_attach(dma_buf, dev->dev,
- &amdgpu_dma_buf_attach_ops, NULL);
+ &amdgpu_dma_buf_attach_ops, obj);
if (IS_ERR(attach)) {
drm_gem_object_put(obj);
return ERR_CAST(attach);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 8ae260822908..8c480c898b0d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -926,6 +926,9 @@ int amdgpu_bo_pin_restricted(struct amdgpu_bo *bo, u32 domain,
return 0;
}

+ if (bo->tbo.base.import_attach)
+ dma_buf_pin(bo->tbo.base.import_attach);
+
bo->flags |= AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS;
/* force to pin into visible video ram */
if (!(bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS))
@@ -1009,6 +1012,9 @@ int amdgpu_bo_unpin(struct amdgpu_bo *bo)

amdgpu_bo_subtract_pin_size(bo);

+ if (bo->tbo.base.import_attach)
+ dma_buf_unpin(bo->tbo.base.import_attach);
+
for (i = 0; i < bo->placement.num_placement; i++) {
bo->placements[i].lpfn = 0;
bo->placements[i].flags &= ~TTM_PL_FLAG_NO_EVICT;
--
2.17.1