[Intel-gfx] [PATCH 4/5] drm/amdgpu: add amdgpu_dma_buf_pin/unpin v2

Christian König
2020-02-18T17:17:06Z

This implements the exporter side of unpinned DMA-buf handling.

v2: fix minor coding style issues

Signed-off-by: Christian König <christian.koenig@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 53 ++++++++++++++++++---
drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 5 ++
2 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index b2ca78b6abce..770baba621b3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -222,6 +222,37 @@ static void amdgpu_dma_buf_detach(struct dma_buf *dmabuf,
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_ops.map_dma_buf implementation
* @attach: DMA-buf attachment
@@ -244,9 +275,19 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
struct sg_table *sgt;
long r;

- r = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT);
- if (r)
- return ERR_PTR(r);
+ if (!bo->pin_count) {
+ /* move buffer into GTT */
+ struct ttm_operation_ctx ctx = { false, false };
+
+ amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
+ r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
+ if (r)
+ return ERR_PTR(r);
+
+ } else if (!(amdgpu_mem_type_to_domain(bo->tbo.mem.mem_type) &
+ AMDGPU_GEM_DOMAIN_GTT)) {
+ return ERR_PTR(-EBUSY);
+ }

sgt = drm_prime_pages_to_sg(bo->tbo.ttm->pages, bo->tbo.num_pages);
if (IS_ERR(sgt))
@@ -277,13 +318,9 @@ static void amdgpu_dma_buf_unmap(struct dma_buf_attachment *attach,
struct sg_table *sgt,
enum dma_data_direction dir)
{
- struct drm_gem_object *obj = attach->dmabuf->priv;
- struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
-
dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
sg_free_table(sgt);
kfree(sgt);
- amdgpu_bo_unpin(bo);
}

/**
@@ -330,6 +367,8 @@ const struct dma_buf_ops amdgpu_dmabuf_ops = {
.dynamic_mapping = true,
.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,
.unmap_dma_buf = amdgpu_dma_buf_unmap,
.release = drm_gem_dmabuf_release,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 6f60a581e3ba..8ae260822908 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/amdgpu_drm.h>
#include <drm/drm_cache.h>
@@ -1274,6 +1275,10 @@ void amdgpu_bo_move_notify(struct ttm_buffer_object *bo,

amdgpu_bo_kunmap(abo);

+ if (abo->tbo.base.dma_buf && !abo->tbo.base.import_attach &&
+ bo->mem.mem_type != TTM_PL_SYSTEM)
+ dma_buf_move_notify(abo->tbo.base.dma_buf);
+
/* remember the eviction */
if (evict)
atomic64_inc(&adev->num_evictions);
--
2.17.1