[PATCH v7 00/21] Move all drivers to a common dma-buf locking convention

[PATCH v7 00/21] Move all drivers to a common dma-buf locking convention

[Dmitry Osipenko]

Hello,

This series moves all drivers to a dynamic dma-buf locking specification.
From now on all dma-buf importers are made responsible for holding
dma-buf's reservation lock around all operations performed over dma-bufs
in accordance to the locking specification. This allows us to utilize
reservation lock more broadly around kernel without fearing of a potential
deadlocks.

This patchset passes all i915 selftests. It was also tested using VirtIO,
Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases
of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate),
which covers majority of kernel drivers since rest of the drivers share
same or similar code paths.

Changelog:

v7: - Rebased on top of recent drm-misc-next.

    - Added ack from Jason Gunthorpe to the RDMA patch.

    - Added iosys_map_clear() to dma_buf_vmap_unlocked(), making it fully
      consistent with dma_buf_vmap().

v6: - Added r-b from Michael Ruhl to the i915 patch.

    - Added acks from Sumit Semwal and updated commit message of the
      "Move dma_buf_vmap() to dynamic locking specification" patch like
      was suggested by Sumit.

    - Added "!dmabuf" check to dma_buf_vmap_unlocked() to match the locked
      variant of the function, for consistency.

v5: - Added acks and r-bs that were given to v4.

    - Changed i915 preparation patch like was suggested by Michael Ruhl.
      The scope of reservation locking is smaller now.

v4: - Added dma_buf_mmap() to the "locking convention" documentation,
      which was missed by accident in v3.

    - Added acks from Christian König, Tomasz Figa and Hans Verkuil that
      they gave to couple v3 patches.

    - Dropped the "_unlocked" postfix from function names that don't have
      the locked variant, as was requested by Christian König.

    - Factored out the per-driver preparations into separate patches
      to ease reviewing of the changes, which is now doable without the
      global dma-buf functions renaming.

    - Factored out the dynamic locking convention enforcements into separate
      patches which add the final dma_resv_assert_held(dmabuf->resv) to the
      dma-buf API functions.

v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
      into aseparate patches, like was suggested by Christian König.

    - Corrected and factored out dma-buf locking documentation into
      a separate patch, like was suggested by Christian König.

    - Intel driver dropped the reservation locking fews days ago from
      its BO-release code path, but we need that locking for the imported
      GEMs because in the end that code path unmaps the imported GEM.
      So I added back the locking needed by the imported GEMs, updating
      the "dma-buf attachment locking specification" patch appropriately.

    - Tested Nouveau+Intel dma-buf import/export combo.

    - Tested udmabuf import to i915/Nouveau/AMDGPU.

    - Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed
      to switch to locked dma-buf vmapping in the drm/gem: Take reservation
      lock for vmap/vunmap operations" patch. In a result invalidated the
      Christian's r-b that he gave to v2.

    - Added locked dma-buf vmap/vunmap functions that are needed for fixing
      vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
      I actually had this change stashed for the drm-shmem shrinker patchset,
      but then realized that it's already needed by the dma-buf patches.
      Also improved my tests to better cover these code paths.

v2: - Changed locking specification to avoid problems with a cross-driver
      ww locking, like was suggested by Christian König. Now the attach/detach
      callbacks are invoked without the held lock and exporter should take the
      lock.

    - Added "locking convention" documentation that explains which dma-buf
      functions and callbacks are locked/unlocked for importers and exporters,
      which was requested by Christian König.

    - Added ack from Tomasz Figa to the V4L patches that he gave to v1.

Dmitry Osipenko (21):
  dma-buf: Add unlocked variant of vmapping functions
  dma-buf: Add unlocked variant of attachment-mapping functions
  drm/gem: Take reservation lock for vmap/vunmap operations
  drm/prime: Prepare to dynamic dma-buf locking specification
  drm/armada: Prepare to dynamic dma-buf locking specification
  drm/i915: Prepare to dynamic dma-buf locking specification
  drm/omapdrm: Prepare to dynamic dma-buf locking specification
  drm/tegra: Prepare to dynamic dma-buf locking specification
  drm/etnaviv: Prepare to dynamic dma-buf locking specification
  RDMA/umem: Prepare to dynamic dma-buf locking specification
  misc: fastrpc: Prepare to dynamic dma-buf locking specification
  xen/gntdev: Prepare to dynamic dma-buf locking specification
  media: videobuf2: Prepare to dynamic dma-buf locking specification
  media: tegra-vde: Prepare to dynamic dma-buf locking specification
  dma-buf: Move dma_buf_vmap() to dynamic locking specification
  dma-buf: Move dma_buf_attach() to dynamic locking specification
  dma-buf: Move dma_buf_map_attachment() to dynamic locking
    specification
  dma-buf: Move dma_buf_mmap() to dynamic locking specification
  dma-buf: Document dynamic locking convention
  media: videobuf2: Stop using internal dma-buf lock
  dma-buf: Remove obsoleted internal lock

 Documentation/driver-api/dma-buf.rst          |   6 +
 drivers/dma-buf/dma-buf.c                     | 216 +++++++++++++++---
 drivers/gpu/drm/armada/armada_gem.c           |   8 +-
 drivers/gpu/drm/drm_client.c                  |   4 +-
 drivers/gpu/drm/drm_gem.c                     |  24 ++
 drivers/gpu/drm/drm_gem_dma_helper.c          |   6 +-
 drivers/gpu/drm/drm_gem_framebuffer_helper.c  |   6 +-
 drivers/gpu/drm/drm_gem_ttm_helper.c          |   9 +-
 drivers/gpu/drm/drm_prime.c                   |   6 +-
 drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c   |   2 +-
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    |   2 +-
 drivers/gpu/drm/i915/gem/i915_gem_object.c    |  14 ++
 .../drm/i915/gem/selftests/i915_gem_dmabuf.c  |  16 +-
 drivers/gpu/drm/lima/lima_sched.c             |   4 +-
 drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c     |   4 +-
 drivers/gpu/drm/panfrost/panfrost_dump.c      |   4 +-
 drivers/gpu/drm/panfrost/panfrost_perfcnt.c   |   6 +-
 drivers/gpu/drm/qxl/qxl_object.c              |  17 +-
 drivers/gpu/drm/qxl/qxl_prime.c               |   4 +-
 drivers/gpu/drm/tegra/gem.c                   |  17 +-
 drivers/infiniband/core/umem_dmabuf.c         |   7 +-
 .../common/videobuf2/videobuf2-dma-contig.c   |  22 +-
 .../media/common/videobuf2/videobuf2-dma-sg.c |  19 +-
 .../common/videobuf2/videobuf2-vmalloc.c      |  17 +-
 .../platform/nvidia/tegra-vde/dmabuf-cache.c  |   6 +-
 drivers/misc/fastrpc.c                        |   6 +-
 drivers/xen/gntdev-dmabuf.c                   |   8 +-
 include/drm/drm_gem.h                         |   3 +
 include/linux/dma-buf.h                       |  17 +-
 29 files changed, 325 insertions(+), 155 deletions(-)

-- 
2.37.3

[PATCH v7 01/21] dma-buf: Add unlocked variant of vmapping functions

[Dmitry Osipenko]

Add unlocked variant of dma_buf_vmap/vunmap() that will be utilized
by drivers that don't take the reservation lock explicitly.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 43 +++++++++++++++++++++++++++++++++++++++
 include/linux/dma-buf.h   |  2 ++
 2 files changed, 45 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index efb4990b29e1..e95fc8dc3aed 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1425,6 +1425,33 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
 
+/**
+ * dma_buf_vmap_unlocked - Create virtual mapping for the buffer object into kernel
+ * address space. Same restrictions as for vmap and friends apply.
+ * @dmabuf:	[in]	buffer to vmap
+ * @map:	[out]	returns the vmap pointer
+ *
+ * Unlocked version of dma_buf_vmap()
+ *
+ * Returns 0 on success, or a negative errno code otherwise.
+ */
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+	int ret;
+
+	iosys_map_clear(map);
+
+	if (WARN_ON(!dmabuf))
+		return -EINVAL;
+
+	dma_resv_lock(dmabuf->resv, NULL);
+	ret = dma_buf_vmap(dmabuf, map);
+	dma_resv_unlock(dmabuf->resv);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vmap_unlocked, DMA_BUF);
+
 /**
  * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
  * @dmabuf:	[in]	buffer to vunmap
@@ -1449,6 +1476,22 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
 
+/**
+ * dma_buf_vunmap_unlocked - Unmap a vmap obtained by dma_buf_vmap.
+ * @dmabuf:	[in]	buffer to vunmap
+ * @map:	[in]	vmap pointer to vunmap
+ */
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+	if (WARN_ON(!dmabuf))
+		return;
+
+	dma_resv_lock(dmabuf->resv, NULL);
+	dma_buf_vunmap(dmabuf, map);
+	dma_resv_unlock(dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap_unlocked, DMA_BUF);
+
 #ifdef CONFIG_DEBUG_FS
 static int dma_buf_debug_show(struct seq_file *s, void *unused)
 {
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 71731796c8c3..8daa054dd7fe 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -632,4 +632,6 @@ int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
 		 unsigned long);
 int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map);
 void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map);
+int dma_buf_vmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map);
+void dma_buf_vunmap_unlocked(struct dma_buf *dmabuf, struct iosys_map *map);
 #endif /* __DMA_BUF_H__ */
-- 
2.37.3

[PATCH v7 02/21] dma-buf: Add unlocked variant of attachment-mapping functions

[Dmitry Osipenko]

Add unlocked variant of dma_buf_map/unmap_attachment() that will
be used by drivers that don't take the reservation lock explicitly.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 53 +++++++++++++++++++++++++++++++++++++++
 include/linux/dma-buf.h   |  6 +++++
 2 files changed, 59 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index e95fc8dc3aed..3e4060dadb74 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1100,6 +1100,34 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment, DMA_BUF);
 
+/**
+ * dma_buf_map_attachment_unlocked - Returns the scatterlist table of the attachment;
+ * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
+ * dma_buf_ops.
+ * @attach:	[in]	attachment whose scatterlist is to be returned
+ * @direction:	[in]	direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_map_attachment().
+ */
+struct sg_table *
+dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
+				enum dma_data_direction direction)
+{
+	struct sg_table *sg_table;
+
+	might_sleep();
+
+	if (WARN_ON(!attach || !attach->dmabuf))
+		return ERR_PTR(-EINVAL);
+
+	dma_resv_lock(attach->dmabuf->resv, NULL);
+	sg_table = dma_buf_map_attachment(attach, direction);
+	dma_resv_unlock(attach->dmabuf->resv);
+
+	return sg_table;
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_map_attachment_unlocked, DMA_BUF);
+
 /**
  * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
  * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
@@ -1136,6 +1164,31 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment, DMA_BUF);
 
+/**
+ * dma_buf_unmap_attachment_unlocked - unmaps and decreases usecount of the buffer;might
+ * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
+ * dma_buf_ops.
+ * @attach:	[in]	attachment to unmap buffer from
+ * @sg_table:	[in]	scatterlist info of the buffer to unmap
+ * @direction:	[in]	direction of DMA transfer
+ *
+ * Unlocked variant of dma_buf_unmap_attachment().
+ */
+void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,
+				       struct sg_table *sg_table,
+				       enum dma_data_direction direction)
+{
+	might_sleep();
+
+	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
+		return;
+
+	dma_resv_lock(attach->dmabuf->resv, NULL);
+	dma_buf_unmap_attachment(attach, sg_table, direction);
+	dma_resv_unlock(attach->dmabuf->resv);
+}
+EXPORT_SYMBOL_NS_GPL(dma_buf_unmap_attachment_unlocked, DMA_BUF);
+
 /**
  * dma_buf_move_notify - notify attachments that DMA-buf is moving
  *
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 8daa054dd7fe..f11b5bbc2f37 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -627,6 +627,12 @@ int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
 			     enum dma_data_direction dir);
 int dma_buf_end_cpu_access(struct dma_buf *dma_buf,
 			   enum dma_data_direction dir);
+struct sg_table *
+dma_buf_map_attachment_unlocked(struct dma_buf_attachment *attach,
+				enum dma_data_direction direction);
+void dma_buf_unmap_attachment_unlocked(struct dma_buf_attachment *attach,
+				       struct sg_table *sg_table,
+				       enum dma_data_direction direction);
 
 int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
 		 unsigned long);
-- 
2.37.3

[PATCH v7 03/21] drm/gem: Take reservation lock for vmap/vunmap operations

[Dmitry Osipenko]

The new common dma-buf locking convention will require buffer importers
to hold the reservation lock around mapping operations. Make DRM GEM core
to take the lock around the vmapping operations and update DRM drivers to
use the locked functions for the case where DRM core now holds the lock.
This patch prepares DRM core and drivers to the common dynamic dma-buf
locking convention.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_client.c                 |  4 ++--
 drivers/gpu/drm/drm_gem.c                    | 24 ++++++++++++++++++++
 drivers/gpu/drm/drm_gem_dma_helper.c         |  6 ++---
 drivers/gpu/drm/drm_gem_framebuffer_helper.c |  6 ++---
 drivers/gpu/drm/drm_gem_ttm_helper.c         |  9 +-------
 drivers/gpu/drm/lima/lima_sched.c            |  4 ++--
 drivers/gpu/drm/panfrost/panfrost_dump.c     |  4 ++--
 drivers/gpu/drm/panfrost/panfrost_perfcnt.c  |  6 ++---
 drivers/gpu/drm/qxl/qxl_object.c             | 17 +++++++-------
 drivers/gpu/drm/qxl/qxl_prime.c              |  4 ++--
 include/drm/drm_gem.h                        |  3 +++
 11 files changed, 54 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 2b230b4d6942..fbcb1e995384 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -323,7 +323,7 @@ drm_client_buffer_vmap(struct drm_client_buffer *buffer,
 	 * fd_install step out of the driver backend hooks, to make that
 	 * final step optional for internal users.
 	 */
-	ret = drm_gem_vmap(buffer->gem, map);
+	ret = drm_gem_vmap_unlocked(buffer->gem, map);
 	if (ret)
 		return ret;
 
@@ -345,7 +345,7 @@ void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
 {
 	struct iosys_map *map = &buffer->map;
 
-	drm_gem_vunmap(buffer->gem, map);
+	drm_gem_vunmap_unlocked(buffer->gem, map);
 }
 EXPORT_SYMBOL(drm_client_buffer_vunmap);
 
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 86d670c71286..dbee4863e4f7 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1171,6 +1171,8 @@ int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map)
 {
 	int ret;
 
+	dma_resv_assert_held(obj->resv);
+
 	if (!obj->funcs->vmap)
 		return -EOPNOTSUPP;
 
@@ -1186,6 +1188,8 @@ EXPORT_SYMBOL(drm_gem_vmap);
 
 void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
 {
+	dma_resv_assert_held(obj->resv);
+
 	if (iosys_map_is_null(map))
 		return;
 
@@ -1197,6 +1201,26 @@ void drm_gem_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
 }
 EXPORT_SYMBOL(drm_gem_vunmap);
 
+int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	int ret;
+
+	dma_resv_lock(obj->resv, NULL);
+	ret = drm_gem_vmap(obj, map);
+	dma_resv_unlock(obj->resv);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_gem_vmap_unlocked);
+
+void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	dma_resv_lock(obj->resv, NULL);
+	drm_gem_vunmap(obj, map);
+	dma_resv_unlock(obj->resv);
+}
+EXPORT_SYMBOL(drm_gem_vunmap_unlocked);
+
 /**
  * drm_gem_lock_reservations - Sets up the ww context and acquires
  * the lock on an array of GEM objects.
diff --git a/drivers/gpu/drm/drm_gem_dma_helper.c b/drivers/gpu/drm/drm_gem_dma_helper.c
index f6901ff97bbb..1e658c448366 100644
--- a/drivers/gpu/drm/drm_gem_dma_helper.c
+++ b/drivers/gpu/drm/drm_gem_dma_helper.c
@@ -230,7 +230,7 @@ void drm_gem_dma_free(struct drm_gem_dma_object *dma_obj)
 
 	if (gem_obj->import_attach) {
 		if (dma_obj->vaddr)
-			dma_buf_vunmap(gem_obj->import_attach->dmabuf, &map);
+			dma_buf_vunmap_unlocked(gem_obj->import_attach->dmabuf, &map);
 		drm_prime_gem_destroy(gem_obj, dma_obj->sgt);
 	} else if (dma_obj->vaddr) {
 		if (dma_obj->map_noncoherent)
@@ -581,7 +581,7 @@ drm_gem_dma_prime_import_sg_table_vmap(struct drm_device *dev,
 	struct iosys_map map;
 	int ret;
 
-	ret = dma_buf_vmap(attach->dmabuf, &map);
+	ret = dma_buf_vmap_unlocked(attach->dmabuf, &map);
 	if (ret) {
 		DRM_ERROR("Failed to vmap PRIME buffer\n");
 		return ERR_PTR(ret);
@@ -589,7 +589,7 @@ drm_gem_dma_prime_import_sg_table_vmap(struct drm_device *dev,
 
 	obj = drm_gem_dma_prime_import_sg_table(dev, attach, sgt);
 	if (IS_ERR(obj)) {
-		dma_buf_vunmap(attach->dmabuf, &map);
+		dma_buf_vunmap_unlocked(attach->dmabuf, &map);
 		return obj;
 	}
 
diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
index 880a4975507f..e35e224e6303 100644
--- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c
+++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c
@@ -354,7 +354,7 @@ int drm_gem_fb_vmap(struct drm_framebuffer *fb, struct iosys_map *map,
 			ret = -EINVAL;
 			goto err_drm_gem_vunmap;
 		}
-		ret = drm_gem_vmap(obj, &map[i]);
+		ret = drm_gem_vmap_unlocked(obj, &map[i]);
 		if (ret)
 			goto err_drm_gem_vunmap;
 	}
@@ -376,7 +376,7 @@ int drm_gem_fb_vmap(struct drm_framebuffer *fb, struct iosys_map *map,
 		obj = drm_gem_fb_get_obj(fb, i);
 		if (!obj)
 			continue;
-		drm_gem_vunmap(obj, &map[i]);
+		drm_gem_vunmap_unlocked(obj, &map[i]);
 	}
 	return ret;
 }
@@ -403,7 +403,7 @@ void drm_gem_fb_vunmap(struct drm_framebuffer *fb, struct iosys_map *map)
 			continue;
 		if (iosys_map_is_null(&map[i]))
 			continue;
-		drm_gem_vunmap(obj, &map[i]);
+		drm_gem_vunmap_unlocked(obj, &map[i]);
 	}
 }
 EXPORT_SYMBOL(drm_gem_fb_vunmap);
diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c
index e5fc875990c4..d5962a34c01d 100644
--- a/drivers/gpu/drm/drm_gem_ttm_helper.c
+++ b/drivers/gpu/drm/drm_gem_ttm_helper.c
@@ -64,13 +64,8 @@ int drm_gem_ttm_vmap(struct drm_gem_object *gem,
 		     struct iosys_map *map)
 {
 	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
-	int ret;
-
-	dma_resv_lock(gem->resv, NULL);
-	ret = ttm_bo_vmap(bo, map);
-	dma_resv_unlock(gem->resv);
 
-	return ret;
+	return ttm_bo_vmap(bo, map);
 }
 EXPORT_SYMBOL(drm_gem_ttm_vmap);
 
@@ -87,9 +82,7 @@ void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
 {
 	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
 
-	dma_resv_lock(gem->resv, NULL);
 	ttm_bo_vunmap(bo, map);
-	dma_resv_unlock(gem->resv);
 }
 EXPORT_SYMBOL(drm_gem_ttm_vunmap);
 
diff --git a/drivers/gpu/drm/lima/lima_sched.c b/drivers/gpu/drm/lima/lima_sched.c
index e82931712d8a..ff003403fbbc 100644
--- a/drivers/gpu/drm/lima/lima_sched.c
+++ b/drivers/gpu/drm/lima/lima_sched.c
@@ -371,7 +371,7 @@ static void lima_sched_build_error_task_list(struct lima_sched_task *task)
 		} else {
 			buffer_chunk->size = lima_bo_size(bo);
 
-			ret = drm_gem_shmem_vmap(&bo->base, &map);
+			ret = drm_gem_vmap_unlocked(&bo->base.base, &map);
 			if (ret) {
 				kvfree(et);
 				goto out;
@@ -379,7 +379,7 @@ static void lima_sched_build_error_task_list(struct lima_sched_task *task)
 
 			memcpy(buffer_chunk + 1, map.vaddr, buffer_chunk->size);
 
-			drm_gem_shmem_vunmap(&bo->base, &map);
+			drm_gem_vunmap_unlocked(&bo->base.base, &map);
 		}
 
 		buffer_chunk = (void *)(buffer_chunk + 1) + buffer_chunk->size;
diff --git a/drivers/gpu/drm/panfrost/panfrost_dump.c b/drivers/gpu/drm/panfrost/panfrost_dump.c
index 89056a1aac7d..f62a019cc523 100644
--- a/drivers/gpu/drm/panfrost/panfrost_dump.c
+++ b/drivers/gpu/drm/panfrost/panfrost_dump.c
@@ -209,7 +209,7 @@ void panfrost_core_dump(struct panfrost_job *job)
 			goto dump_header;
 		}
 
-		ret = drm_gem_shmem_vmap(&bo->base, &map);
+		ret = drm_gem_vmap_unlocked(&bo->base.base, &map);
 		if (ret) {
 			dev_err(pfdev->dev, "Panfrost Dump: couldn't map Buffer Object\n");
 			iter.hdr->bomap.valid = 0;
@@ -236,7 +236,7 @@ void panfrost_core_dump(struct panfrost_job *job)
 		vaddr = map.vaddr;
 		memcpy(iter.data, vaddr, bo->base.base.size);
 
-		drm_gem_shmem_vunmap(&bo->base, &map);
+		drm_gem_vunmap_unlocked(&bo->base.base, &map);
 
 		iter.hdr->bomap.valid = cpu_to_le32(1);
 
diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
index bc0df93f7f21..ba9b6e2b2636 100644
--- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
+++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
@@ -106,7 +106,7 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
 		goto err_close_bo;
 	}
 
-	ret = drm_gem_shmem_vmap(bo, &map);
+	ret = drm_gem_vmap_unlocked(&bo->base, &map);
 	if (ret)
 		goto err_put_mapping;
 	perfcnt->buf = map.vaddr;
@@ -165,7 +165,7 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
 	return 0;
 
 err_vunmap:
-	drm_gem_shmem_vunmap(bo, &map);
+	drm_gem_vunmap_unlocked(&bo->base, &map);
 err_put_mapping:
 	panfrost_gem_mapping_put(perfcnt->mapping);
 err_close_bo:
@@ -195,7 +195,7 @@ static int panfrost_perfcnt_disable_locked(struct panfrost_device *pfdev,
 		  GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF));
 
 	perfcnt->user = NULL;
-	drm_gem_shmem_vunmap(&perfcnt->mapping->obj->base, &map);
+	drm_gem_vunmap_unlocked(&perfcnt->mapping->obj->base.base, &map);
 	perfcnt->buf = NULL;
 	panfrost_gem_close(&perfcnt->mapping->obj->base.base, file_priv);
 	panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu);
diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
index 695d9308d1f0..06a58dad5f5c 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -168,9 +168,16 @@ int qxl_bo_vmap_locked(struct qxl_bo *bo, struct iosys_map *map)
 		bo->map_count++;
 		goto out;
 	}
-	r = ttm_bo_vmap(&bo->tbo, &bo->map);
+
+	r = __qxl_bo_pin(bo);
 	if (r)
 		return r;
+
+	r = ttm_bo_vmap(&bo->tbo, &bo->map);
+	if (r) {
+		__qxl_bo_unpin(bo);
+		return r;
+	}
 	bo->map_count = 1;
 
 	/* TODO: Remove kptr in favor of map everywhere. */
@@ -192,12 +199,6 @@ int qxl_bo_vmap(struct qxl_bo *bo, struct iosys_map *map)
 	if (r)
 		return r;
 
-	r = __qxl_bo_pin(bo);
-	if (r) {
-		qxl_bo_unreserve(bo);
-		return r;
-	}
-
 	r = qxl_bo_vmap_locked(bo, map);
 	qxl_bo_unreserve(bo);
 	return r;
@@ -247,6 +248,7 @@ void qxl_bo_vunmap_locked(struct qxl_bo *bo)
 		return;
 	bo->kptr = NULL;
 	ttm_bo_vunmap(&bo->tbo, &bo->map);
+	__qxl_bo_unpin(bo);
 }
 
 int qxl_bo_vunmap(struct qxl_bo *bo)
@@ -258,7 +260,6 @@ int qxl_bo_vunmap(struct qxl_bo *bo)
 		return r;
 
 	qxl_bo_vunmap_locked(bo);
-	__qxl_bo_unpin(bo);
 	qxl_bo_unreserve(bo);
 	return 0;
 }
diff --git a/drivers/gpu/drm/qxl/qxl_prime.c b/drivers/gpu/drm/qxl/qxl_prime.c
index 142d01415acb..9169c26357d3 100644
--- a/drivers/gpu/drm/qxl/qxl_prime.c
+++ b/drivers/gpu/drm/qxl/qxl_prime.c
@@ -59,7 +59,7 @@ int qxl_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
 	struct qxl_bo *bo = gem_to_qxl_bo(obj);
 	int ret;
 
-	ret = qxl_bo_vmap(bo, map);
+	ret = qxl_bo_vmap_locked(bo, map);
 	if (ret < 0)
 		return ret;
 
@@ -71,5 +71,5 @@ void qxl_gem_prime_vunmap(struct drm_gem_object *obj,
 {
 	struct qxl_bo *bo = gem_to_qxl_bo(obj);
 
-	qxl_bo_vunmap(bo);
+	qxl_bo_vunmap_locked(bo);
 }
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 58a18a17c67e..ed82039bfd5b 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -408,6 +408,9 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj);
 void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
 		bool dirty, bool accessed);
 
+int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
+void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
+
 int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
 			   int count, struct drm_gem_object ***objs_out);
 struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
-- 
2.37.3

[PATCH v7 04/21] drm/prime: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare DRM prime core to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_prime.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index a3f180653b8b..ef50c4e2e509 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -936,7 +936,7 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
 
 	get_dma_buf(dma_buf);
 
-	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	sgt = dma_buf_map_attachment_unlocked(attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(sgt)) {
 		ret = PTR_ERR(sgt);
 		goto fail_detach;
@@ -954,7 +954,7 @@ struct drm_gem_object *drm_gem_prime_import_dev(struct drm_device *dev,
 	return obj;
 
 fail_unmap:
-	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+	dma_buf_unmap_attachment_unlocked(attach, sgt, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
 	dma_buf_put(dma_buf);
@@ -1052,7 +1052,7 @@ void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg)
 
 	attach = obj->import_attach;
 	if (sg)
-		dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
+		dma_buf_unmap_attachment_unlocked(attach, sg, DMA_BIDIRECTIONAL);
 	dma_buf = attach->dmabuf;
 	dma_buf_detach(attach->dmabuf, attach);
 	/* remove the reference */
-- 
2.37.3

[PATCH v7 05/21] drm/armada: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare Armada driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/armada/armada_gem.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/armada/armada_gem.c b/drivers/gpu/drm/armada/armada_gem.c
index 5430265ad458..26d10065d534 100644
--- a/drivers/gpu/drm/armada/armada_gem.c
+++ b/drivers/gpu/drm/armada/armada_gem.c
@@ -66,8 +66,8 @@ void armada_gem_free_object(struct drm_gem_object *obj)
 	if (dobj->obj.import_attach) {
 		/* We only ever display imported data */
 		if (dobj->sgt)
-			dma_buf_unmap_attachment(dobj->obj.import_attach,
-						 dobj->sgt, DMA_TO_DEVICE);
+			dma_buf_unmap_attachment_unlocked(dobj->obj.import_attach,
+							  dobj->sgt, DMA_TO_DEVICE);
 		drm_prime_gem_destroy(&dobj->obj, NULL);
 	}
 
@@ -539,8 +539,8 @@ int armada_gem_map_import(struct armada_gem_object *dobj)
 {
 	int ret;
 
-	dobj->sgt = dma_buf_map_attachment(dobj->obj.import_attach,
-					   DMA_TO_DEVICE);
+	dobj->sgt = dma_buf_map_attachment_unlocked(dobj->obj.import_attach,
+						    DMA_TO_DEVICE);
 	if (IS_ERR(dobj->sgt)) {
 		ret = PTR_ERR(dobj->sgt);
 		dobj->sgt = NULL;
-- 
2.37.3

[PATCH v7 06/21] drm/i915: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare i915 driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions
and handling cases where importer now holds the reservation lock.

Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c       |  2 +-
 drivers/gpu/drm/i915/gem/i915_gem_object.c       | 14 ++++++++++++++
 .../gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c | 16 ++++++++--------
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index f5062d0c6333..07eee1c09aaf 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -72,7 +72,7 @@ static int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf,
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	void *vaddr;
 
-	vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
+	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
 	if (IS_ERR(vaddr))
 		return PTR_ERR(vaddr);
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 85482a04d158..7cab89618bad 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -290,7 +290,21 @@ void __i915_gem_object_pages_fini(struct drm_i915_gem_object *obj)
 	__i915_gem_object_free_mmaps(obj);
 
 	atomic_set(&obj->mm.pages_pin_count, 0);
+
+	/*
+	 * dma_buf_unmap_attachment() requires reservation to be
+	 * locked. The imported GEM shouldn't share reservation lock
+	 * and ttm_bo_cleanup_memtype_use() shouldn't be invoked for
+	 * dma-buf, so it's safe to take the lock.
+	 */
+	if (obj->base.import_attach)
+		i915_gem_object_lock(obj, NULL);
+
 	__i915_gem_object_put_pages(obj);
+
+	if (obj->base.import_attach)
+		i915_gem_object_unlock(obj);
+
 	GEM_BUG_ON(i915_gem_object_has_pages(obj));
 }
 
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
index 51ed824b020c..f2f3cfad807b 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
@@ -213,7 +213,7 @@ static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
 		goto out_import;
 	}
 
-	st = dma_buf_map_attachment(import_attach, DMA_BIDIRECTIONAL);
+	st = dma_buf_map_attachment_unlocked(import_attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(st)) {
 		err = PTR_ERR(st);
 		goto out_detach;
@@ -226,7 +226,7 @@ static int igt_dmabuf_import_same_driver(struct drm_i915_private *i915,
 		timeout = -ETIME;
 	}
 	err = timeout > 0 ? 0 : timeout;
-	dma_buf_unmap_attachment(import_attach, st, DMA_BIDIRECTIONAL);
+	dma_buf_unmap_attachment_unlocked(import_attach, st, DMA_BIDIRECTIONAL);
 out_detach:
 	dma_buf_detach(dmabuf, import_attach);
 out_import:
@@ -296,7 +296,7 @@ static int igt_dmabuf_import(void *arg)
 		goto out_obj;
 	}
 
-	err = dma_buf_vmap(dmabuf, &map);
+	err = dma_buf_vmap_unlocked(dmabuf, &map);
 	dma_map = err ? NULL : map.vaddr;
 	if (!dma_map) {
 		pr_err("dma_buf_vmap failed\n");
@@ -337,7 +337,7 @@ static int igt_dmabuf_import(void *arg)
 
 	err = 0;
 out_dma_map:
-	dma_buf_vunmap(dmabuf, &map);
+	dma_buf_vunmap_unlocked(dmabuf, &map);
 out_obj:
 	i915_gem_object_put(obj);
 out_dmabuf:
@@ -358,7 +358,7 @@ static int igt_dmabuf_import_ownership(void *arg)
 	if (IS_ERR(dmabuf))
 		return PTR_ERR(dmabuf);
 
-	err = dma_buf_vmap(dmabuf, &map);
+	err = dma_buf_vmap_unlocked(dmabuf, &map);
 	ptr = err ? NULL : map.vaddr;
 	if (!ptr) {
 		pr_err("dma_buf_vmap failed\n");
@@ -367,7 +367,7 @@ static int igt_dmabuf_import_ownership(void *arg)
 	}
 
 	memset(ptr, 0xc5, PAGE_SIZE);
-	dma_buf_vunmap(dmabuf, &map);
+	dma_buf_vunmap_unlocked(dmabuf, &map);
 
 	obj = to_intel_bo(i915_gem_prime_import(&i915->drm, dmabuf));
 	if (IS_ERR(obj)) {
@@ -418,7 +418,7 @@ static int igt_dmabuf_export_vmap(void *arg)
 	}
 	i915_gem_object_put(obj);
 
-	err = dma_buf_vmap(dmabuf, &map);
+	err = dma_buf_vmap_unlocked(dmabuf, &map);
 	ptr = err ? NULL : map.vaddr;
 	if (!ptr) {
 		pr_err("dma_buf_vmap failed\n");
@@ -435,7 +435,7 @@ static int igt_dmabuf_export_vmap(void *arg)
 	memset(ptr, 0xc5, dmabuf->size);
 
 	err = 0;
-	dma_buf_vunmap(dmabuf, &map);
+	dma_buf_vunmap_unlocked(dmabuf, &map);
 out:
 	dma_buf_put(dmabuf);
 	return err;
-- 
2.37.3

[PATCH v7 07/21] drm/omapdrm: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare OMAP DRM driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
index 393f82e26927..8e194dbc9506 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
@@ -125,7 +125,7 @@ struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 
 	get_dma_buf(dma_buf);
 
-	sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
+	sgt = dma_buf_map_attachment_unlocked(attach, DMA_TO_DEVICE);
 	if (IS_ERR(sgt)) {
 		ret = PTR_ERR(sgt);
 		goto fail_detach;
@@ -142,7 +142,7 @@ struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
 	return obj;
 
 fail_unmap:
-	dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
+	dma_buf_unmap_attachment_unlocked(attach, sgt, DMA_TO_DEVICE);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
 	dma_buf_put(dma_buf);
-- 
2.37.3

[PATCH v7 08/21] drm/tegra: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare Tegra DRM driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/tegra/gem.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 81991090adcc..b09b8ab40ae4 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -84,7 +84,7 @@ static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_
 			goto free;
 		}
 
-		map->sgt = dma_buf_map_attachment(map->attach, direction);
+		map->sgt = dma_buf_map_attachment_unlocked(map->attach, direction);
 		if (IS_ERR(map->sgt)) {
 			dma_buf_detach(buf, map->attach);
 			err = PTR_ERR(map->sgt);
@@ -160,7 +160,8 @@ static struct host1x_bo_mapping *tegra_bo_pin(struct device *dev, struct host1x_
 static void tegra_bo_unpin(struct host1x_bo_mapping *map)
 {
 	if (map->attach) {
-		dma_buf_unmap_attachment(map->attach, map->sgt, map->direction);
+		dma_buf_unmap_attachment_unlocked(map->attach, map->sgt,
+						  map->direction);
 		dma_buf_detach(map->attach->dmabuf, map->attach);
 	} else {
 		dma_unmap_sgtable(map->dev, map->sgt, map->direction, 0);
@@ -181,7 +182,7 @@ static void *tegra_bo_mmap(struct host1x_bo *bo)
 	if (obj->vaddr) {
 		return obj->vaddr;
 	} else if (obj->gem.import_attach) {
-		ret = dma_buf_vmap(obj->gem.import_attach->dmabuf, &map);
+		ret = dma_buf_vmap_unlocked(obj->gem.import_attach->dmabuf, &map);
 		return ret ? NULL : map.vaddr;
 	} else {
 		return vmap(obj->pages, obj->num_pages, VM_MAP,
@@ -197,7 +198,7 @@ static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
 	if (obj->vaddr)
 		return;
 	else if (obj->gem.import_attach)
-		dma_buf_vunmap(obj->gem.import_attach->dmabuf, &map);
+		dma_buf_vunmap_unlocked(obj->gem.import_attach->dmabuf, &map);
 	else
 		vunmap(addr);
 }
@@ -461,7 +462,7 @@ static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
 
 	get_dma_buf(buf);
 
-	bo->sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
+	bo->sgt = dma_buf_map_attachment_unlocked(attach, DMA_TO_DEVICE);
 	if (IS_ERR(bo->sgt)) {
 		err = PTR_ERR(bo->sgt);
 		goto detach;
@@ -479,7 +480,7 @@ static struct tegra_bo *tegra_bo_import(struct drm_device *drm,
 
 detach:
 	if (!IS_ERR_OR_NULL(bo->sgt))
-		dma_buf_unmap_attachment(attach, bo->sgt, DMA_TO_DEVICE);
+		dma_buf_unmap_attachment_unlocked(attach, bo->sgt, DMA_TO_DEVICE);
 
 	dma_buf_detach(buf, attach);
 	dma_buf_put(buf);
@@ -508,8 +509,8 @@ void tegra_bo_free_object(struct drm_gem_object *gem)
 		tegra_bo_iommu_unmap(tegra, bo);
 
 	if (gem->import_attach) {
-		dma_buf_unmap_attachment(gem->import_attach, bo->sgt,
-					 DMA_TO_DEVICE);
+		dma_buf_unmap_attachment_unlocked(gem->import_attach, bo->sgt,
+						  DMA_TO_DEVICE);
 		drm_prime_gem_destroy(gem, NULL);
 	} else {
 		tegra_bo_free(gem->dev, bo);
-- 
2.37.3

[PATCH v7 09/21] drm/etnaviv: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare Etnaviv driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index 3fa2da149639..7031db145a77 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -65,7 +65,7 @@ static void etnaviv_gem_prime_release(struct etnaviv_gem_object *etnaviv_obj)
 	struct iosys_map map = IOSYS_MAP_INIT_VADDR(etnaviv_obj->vaddr);
 
 	if (etnaviv_obj->vaddr)
-		dma_buf_vunmap(etnaviv_obj->base.import_attach->dmabuf, &map);
+		dma_buf_vunmap_unlocked(etnaviv_obj->base.import_attach->dmabuf, &map);
 
 	/* Don't drop the pages for imported dmabuf, as they are not
 	 * ours, just free the array we allocated:
-- 
2.37.3

[PATCH v7 10/21] RDMA/umem: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare InfiniBand drivers to the common dynamic dma-buf locking
convention by starting to use the unlocked versions of dma-buf API
functions.

Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/infiniband/core/umem_dmabuf.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
index 04c04e6d24c3..43b26bc12288 100644
--- a/drivers/infiniband/core/umem_dmabuf.c
+++ b/drivers/infiniband/core/umem_dmabuf.c
@@ -26,7 +26,8 @@ int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
 	if (umem_dmabuf->sgt)
 		goto wait_fence;
 
-	sgt = dma_buf_map_attachment(umem_dmabuf->attach, DMA_BIDIRECTIONAL);
+	sgt = dma_buf_map_attachment_unlocked(umem_dmabuf->attach,
+					      DMA_BIDIRECTIONAL);
 	if (IS_ERR(sgt))
 		return PTR_ERR(sgt);
 
@@ -102,8 +103,8 @@ void ib_umem_dmabuf_unmap_pages(struct ib_umem_dmabuf *umem_dmabuf)
 		umem_dmabuf->last_sg_trim = 0;
 	}
 
-	dma_buf_unmap_attachment(umem_dmabuf->attach, umem_dmabuf->sgt,
-				 DMA_BIDIRECTIONAL);
+	dma_buf_unmap_attachment_unlocked(umem_dmabuf->attach, umem_dmabuf->sgt,
+					  DMA_BIDIRECTIONAL);
 
 	umem_dmabuf->sgt = NULL;
 }
-- 
2.37.3

[PATCH v7 11/21] misc: fastrpc: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare fastrpc to the common dynamic dma-buf locking convention by
starting to use the unlocked versions of dma-buf API functions.

Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/misc/fastrpc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 93ebd174d848..6fcfb2e9f7a7 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -310,8 +310,8 @@ static void fastrpc_free_map(struct kref *ref)
 				return;
 			}
 		}
-		dma_buf_unmap_attachment(map->attach, map->table,
-					 DMA_BIDIRECTIONAL);
+		dma_buf_unmap_attachment_unlocked(map->attach, map->table,
+						  DMA_BIDIRECTIONAL);
 		dma_buf_detach(map->buf, map->attach);
 		dma_buf_put(map->buf);
 	}
@@ -726,7 +726,7 @@ static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
 		goto attach_err;
 	}
 
-	map->table = dma_buf_map_attachment(map->attach, DMA_BIDIRECTIONAL);
+	map->table = dma_buf_map_attachment_unlocked(map->attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(map->table)) {
 		err = PTR_ERR(map->table);
 		goto map_err;
-- 
2.37.3

[PATCH v7 12/21] xen/gntdev: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare gntdev driver to the common dynamic dma-buf locking convention
by starting to use the unlocked versions of dma-buf API functions.

Acked-by: Juergen Gross <jgross@suse.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/xen/gntdev-dmabuf.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c
index 940e5e9e8a54..4440e626b797 100644
--- a/drivers/xen/gntdev-dmabuf.c
+++ b/drivers/xen/gntdev-dmabuf.c
@@ -600,7 +600,7 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct device *dev,
 
 	gntdev_dmabuf->u.imp.attach = attach;
 
-	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	sgt = dma_buf_map_attachment_unlocked(attach, DMA_BIDIRECTIONAL);
 	if (IS_ERR(sgt)) {
 		ret = ERR_CAST(sgt);
 		goto fail_detach;
@@ -658,7 +658,7 @@ dmabuf_imp_to_refs(struct gntdev_dmabuf_priv *priv, struct device *dev,
 fail_end_access:
 	dmabuf_imp_end_foreign_access(gntdev_dmabuf->u.imp.refs, count);
 fail_unmap:
-	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+	dma_buf_unmap_attachment_unlocked(attach, sgt, DMA_BIDIRECTIONAL);
 fail_detach:
 	dma_buf_detach(dma_buf, attach);
 fail_free_obj:
@@ -708,8 +708,8 @@ static int dmabuf_imp_release(struct gntdev_dmabuf_priv *priv, u32 fd)
 	attach = gntdev_dmabuf->u.imp.attach;
 
 	if (gntdev_dmabuf->u.imp.sgt)
-		dma_buf_unmap_attachment(attach, gntdev_dmabuf->u.imp.sgt,
-					 DMA_BIDIRECTIONAL);
+		dma_buf_unmap_attachment_unlocked(attach, gntdev_dmabuf->u.imp.sgt,
+						  DMA_BIDIRECTIONAL);
 	dma_buf = attach->dmabuf;
 	dma_buf_detach(attach->dmabuf, attach);
 	dma_buf_put(dma_buf);
-- 
2.37.3

[PATCH v7 13/21] media: videobuf2: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare V4L2 memory allocators to the common dynamic dma-buf locking
convention by starting to use the unlocked versions of dma-buf API
functions.

Acked-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/media/common/videobuf2/videobuf2-dma-contig.c | 11 ++++++-----
 drivers/media/common/videobuf2/videobuf2-dma-sg.c     |  8 ++++----
 drivers/media/common/videobuf2/videobuf2-vmalloc.c    |  6 +++---
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index 678b359717c4..79f4d8301fbb 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -101,7 +101,7 @@ static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv)
 	if (buf->db_attach) {
 		struct iosys_map map;
 
-		if (!dma_buf_vmap(buf->db_attach->dmabuf, &map))
+		if (!dma_buf_vmap_unlocked(buf->db_attach->dmabuf, &map))
 			buf->vaddr = map.vaddr;
 
 		return buf->vaddr;
@@ -711,7 +711,7 @@ static int vb2_dc_map_dmabuf(void *mem_priv)
 	}
 
 	/* get the associated scatterlist for this buffer */
-	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
+	sgt = dma_buf_map_attachment_unlocked(buf->db_attach, buf->dma_dir);
 	if (IS_ERR(sgt)) {
 		pr_err("Error getting dmabuf scatterlist\n");
 		return -EINVAL;
@@ -722,7 +722,8 @@ static int vb2_dc_map_dmabuf(void *mem_priv)
 	if (contig_size < buf->size) {
 		pr_err("contiguous chunk is too small %lu/%lu\n",
 		       contig_size, buf->size);
-		dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+		dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt,
+						  buf->dma_dir);
 		return -EFAULT;
 	}
 
@@ -750,10 +751,10 @@ static void vb2_dc_unmap_dmabuf(void *mem_priv)
 	}
 
 	if (buf->vaddr) {
-		dma_buf_vunmap(buf->db_attach->dmabuf, &map);
+		dma_buf_vunmap_unlocked(buf->db_attach->dmabuf, &map);
 		buf->vaddr = NULL;
 	}
-	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+	dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt, buf->dma_dir);
 
 	buf->dma_addr = 0;
 	buf->dma_sgt = NULL;
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index fa69158a65b1..36ecdea8d707 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -309,7 +309,7 @@ static void *vb2_dma_sg_vaddr(struct vb2_buffer *vb, void *buf_priv)
 
 	if (!buf->vaddr) {
 		if (buf->db_attach) {
-			ret = dma_buf_vmap(buf->db_attach->dmabuf, &map);
+			ret = dma_buf_vmap_unlocked(buf->db_attach->dmabuf, &map);
 			buf->vaddr = ret ? NULL : map.vaddr;
 		} else {
 			buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1);
@@ -565,7 +565,7 @@ static int vb2_dma_sg_map_dmabuf(void *mem_priv)
 	}
 
 	/* get the associated scatterlist for this buffer */
-	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
+	sgt = dma_buf_map_attachment_unlocked(buf->db_attach, buf->dma_dir);
 	if (IS_ERR(sgt)) {
 		pr_err("Error getting dmabuf scatterlist\n");
 		return -EINVAL;
@@ -594,10 +594,10 @@ static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
 	}
 
 	if (buf->vaddr) {
-		dma_buf_vunmap(buf->db_attach->dmabuf, &map);
+		dma_buf_vunmap_unlocked(buf->db_attach->dmabuf, &map);
 		buf->vaddr = NULL;
 	}
-	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+	dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt, buf->dma_dir);
 
 	buf->dma_sgt = NULL;
 }
diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
index 948152f1596b..7831bf545874 100644
--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
@@ -376,7 +376,7 @@ static int vb2_vmalloc_map_dmabuf(void *mem_priv)
 	struct iosys_map map;
 	int ret;
 
-	ret = dma_buf_vmap(buf->dbuf, &map);
+	ret = dma_buf_vmap_unlocked(buf->dbuf, &map);
 	if (ret)
 		return -EFAULT;
 	buf->vaddr = map.vaddr;
@@ -389,7 +389,7 @@ static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
 	struct vb2_vmalloc_buf *buf = mem_priv;
 	struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
 
-	dma_buf_vunmap(buf->dbuf, &map);
+	dma_buf_vunmap_unlocked(buf->dbuf, &map);
 	buf->vaddr = NULL;
 }
 
@@ -399,7 +399,7 @@ static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
 	struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
 
 	if (buf->vaddr)
-		dma_buf_vunmap(buf->dbuf, &map);
+		dma_buf_vunmap_unlocked(buf->dbuf, &map);
 
 	kfree(buf);
 }
-- 
2.37.3

Re: [PATCH v7 13/21] media: videobuf2: Prepare to dynamic dma-buf locking specification

[Hans Verkuil]

On 10/17/22 19:22, Dmitry Osipenko wrote:
> Prepare V4L2 memory allocators to the common dynamic dma-buf locking
> convention by starting to use the unlocked versions of dma-buf API
> functions.
> 
> Acked-by: Tomasz Figa <tfiga@chromium.org>

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Thanks!

	Hans

> Acked-by: Christian König <christian.koenig@amd.com>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
>  drivers/media/common/videobuf2/videobuf2-dma-contig.c | 11 ++++++-----
>  drivers/media/common/videobuf2/videobuf2-dma-sg.c     |  8 ++++----
>  drivers/media/common/videobuf2/videobuf2-vmalloc.c    |  6 +++---
>  3 files changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> index 678b359717c4..79f4d8301fbb 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
> @@ -101,7 +101,7 @@ static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv)
>  	if (buf->db_attach) {
>  		struct iosys_map map;
>  
> -		if (!dma_buf_vmap(buf->db_attach->dmabuf, &map))
> +		if (!dma_buf_vmap_unlocked(buf->db_attach->dmabuf, &map))
>  			buf->vaddr = map.vaddr;
>  
>  		return buf->vaddr;
> @@ -711,7 +711,7 @@ static int vb2_dc_map_dmabuf(void *mem_priv)
>  	}
>  
>  	/* get the associated scatterlist for this buffer */
> -	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
> +	sgt = dma_buf_map_attachment_unlocked(buf->db_attach, buf->dma_dir);
>  	if (IS_ERR(sgt)) {
>  		pr_err("Error getting dmabuf scatterlist\n");
>  		return -EINVAL;
> @@ -722,7 +722,8 @@ static int vb2_dc_map_dmabuf(void *mem_priv)
>  	if (contig_size < buf->size) {
>  		pr_err("contiguous chunk is too small %lu/%lu\n",
>  		       contig_size, buf->size);
> -		dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
> +		dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt,
> +						  buf->dma_dir);
>  		return -EFAULT;
>  	}
>  
> @@ -750,10 +751,10 @@ static void vb2_dc_unmap_dmabuf(void *mem_priv)
>  	}
>  
>  	if (buf->vaddr) {
> -		dma_buf_vunmap(buf->db_attach->dmabuf, &map);
> +		dma_buf_vunmap_unlocked(buf->db_attach->dmabuf, &map);
>  		buf->vaddr = NULL;
>  	}
> -	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
> +	dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt, buf->dma_dir);
>  
>  	buf->dma_addr = 0;
>  	buf->dma_sgt = NULL;
> diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> index fa69158a65b1..36ecdea8d707 100644
> --- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
> @@ -309,7 +309,7 @@ static void *vb2_dma_sg_vaddr(struct vb2_buffer *vb, void *buf_priv)
>  
>  	if (!buf->vaddr) {
>  		if (buf->db_attach) {
> -			ret = dma_buf_vmap(buf->db_attach->dmabuf, &map);
> +			ret = dma_buf_vmap_unlocked(buf->db_attach->dmabuf, &map);
>  			buf->vaddr = ret ? NULL : map.vaddr;
>  		} else {
>  			buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1);
> @@ -565,7 +565,7 @@ static int vb2_dma_sg_map_dmabuf(void *mem_priv)
>  	}
>  
>  	/* get the associated scatterlist for this buffer */
> -	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
> +	sgt = dma_buf_map_attachment_unlocked(buf->db_attach, buf->dma_dir);
>  	if (IS_ERR(sgt)) {
>  		pr_err("Error getting dmabuf scatterlist\n");
>  		return -EINVAL;
> @@ -594,10 +594,10 @@ static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
>  	}
>  
>  	if (buf->vaddr) {
> -		dma_buf_vunmap(buf->db_attach->dmabuf, &map);
> +		dma_buf_vunmap_unlocked(buf->db_attach->dmabuf, &map);
>  		buf->vaddr = NULL;
>  	}
> -	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
> +	dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt, buf->dma_dir);
>  
>  	buf->dma_sgt = NULL;
>  }
> diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
> index 948152f1596b..7831bf545874 100644
> --- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
> +++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
> @@ -376,7 +376,7 @@ static int vb2_vmalloc_map_dmabuf(void *mem_priv)
>  	struct iosys_map map;
>  	int ret;
>  
> -	ret = dma_buf_vmap(buf->dbuf, &map);
> +	ret = dma_buf_vmap_unlocked(buf->dbuf, &map);
>  	if (ret)
>  		return -EFAULT;
>  	buf->vaddr = map.vaddr;
> @@ -389,7 +389,7 @@ static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
>  	struct vb2_vmalloc_buf *buf = mem_priv;
>  	struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
>  
> -	dma_buf_vunmap(buf->dbuf, &map);
> +	dma_buf_vunmap_unlocked(buf->dbuf, &map);
>  	buf->vaddr = NULL;
>  }
>  
> @@ -399,7 +399,7 @@ static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
>  	struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
>  
>  	if (buf->vaddr)
> -		dma_buf_vunmap(buf->dbuf, &map);
> +		dma_buf_vunmap_unlocked(buf->dbuf, &map);
>  
>  	kfree(buf);
>  }

[PATCH v7 14/21] media: tegra-vde: Prepare to dynamic dma-buf locking specification

[Dmitry Osipenko]

Prepare Tegra video decoder driver to the common dynamic dma-buf
locking convention by starting to use the unlocked versions of dma-buf
API functions.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c b/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c
index 69c346148070..1c5b94989aec 100644
--- a/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c
+++ b/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c
@@ -38,7 +38,7 @@ static void tegra_vde_release_entry(struct tegra_vde_cache_entry *entry)
 	if (entry->vde->domain)
 		tegra_vde_iommu_unmap(entry->vde, entry->iova);
 
-	dma_buf_unmap_attachment(entry->a, entry->sgt, entry->dma_dir);
+	dma_buf_unmap_attachment_unlocked(entry->a, entry->sgt, entry->dma_dir);
 	dma_buf_detach(dmabuf, entry->a);
 	dma_buf_put(dmabuf);
 
@@ -102,7 +102,7 @@ int tegra_vde_dmabuf_cache_map(struct tegra_vde *vde,
 		goto err_unlock;
 	}
 
-	sgt = dma_buf_map_attachment(attachment, dma_dir);
+	sgt = dma_buf_map_attachment_unlocked(attachment, dma_dir);
 	if (IS_ERR(sgt)) {
 		dev_err(dev, "Failed to get dmabufs sg_table\n");
 		err = PTR_ERR(sgt);
@@ -152,7 +152,7 @@ int tegra_vde_dmabuf_cache_map(struct tegra_vde *vde,
 err_free:
 	kfree(entry);
 err_unmap:
-	dma_buf_unmap_attachment(attachment, sgt, dma_dir);
+	dma_buf_unmap_attachment_unlocked(attachment, sgt, dma_dir);
 err_detach:
 	dma_buf_detach(dmabuf, attachment);
 err_unlock:
-- 
2.37.3

Re: [PATCH v7 14/21] media: tegra-vde: Prepare to dynamic dma-buf locking specification

[Hans Verkuil]

On 10/17/22 19:22, Dmitry Osipenko wrote:
> Prepare Tegra video decoder driver to the common dynamic dma-buf
> locking convention by starting to use the unlocked versions of dma-buf
> API functions.
> 
> Acked-by: Christian König <christian.koenig@amd.com>

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Thanks!

	Hans

> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
>  drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c b/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c
> index 69c346148070..1c5b94989aec 100644
> --- a/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c
> +++ b/drivers/media/platform/nvidia/tegra-vde/dmabuf-cache.c
> @@ -38,7 +38,7 @@ static void tegra_vde_release_entry(struct tegra_vde_cache_entry *entry)
>  	if (entry->vde->domain)
>  		tegra_vde_iommu_unmap(entry->vde, entry->iova);
>  
> -	dma_buf_unmap_attachment(entry->a, entry->sgt, entry->dma_dir);
> +	dma_buf_unmap_attachment_unlocked(entry->a, entry->sgt, entry->dma_dir);
>  	dma_buf_detach(dmabuf, entry->a);
>  	dma_buf_put(dmabuf);
>  
> @@ -102,7 +102,7 @@ int tegra_vde_dmabuf_cache_map(struct tegra_vde *vde,
>  		goto err_unlock;
>  	}
>  
> -	sgt = dma_buf_map_attachment(attachment, dma_dir);
> +	sgt = dma_buf_map_attachment_unlocked(attachment, dma_dir);
>  	if (IS_ERR(sgt)) {
>  		dev_err(dev, "Failed to get dmabufs sg_table\n");
>  		err = PTR_ERR(sgt);
> @@ -152,7 +152,7 @@ int tegra_vde_dmabuf_cache_map(struct tegra_vde *vde,
>  err_free:
>  	kfree(entry);
>  err_unmap:
> -	dma_buf_unmap_attachment(attachment, sgt, dma_dir);
> +	dma_buf_unmap_attachment_unlocked(attachment, sgt, dma_dir);
>  err_detach:
>  	dma_buf_detach(dmabuf, attachment);
>  err_unlock:

[PATCH v7 15/21] dma-buf: Move dma_buf_vmap() to dynamic locking specification

[Dmitry Osipenko]

Move dma_buf_vmap/vunmap() functions to the dynamic locking
specification by asserting that the reservation lock is held.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 3e4060dadb74..2c4381bb9478 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1450,6 +1450,8 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	if (WARN_ON(!dmabuf))
 		return -EINVAL;
 
+	dma_resv_assert_held(dmabuf->resv);
+
 	if (!dmabuf->ops->vmap)
 		return -EINVAL;
 
@@ -1515,6 +1517,8 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	if (WARN_ON(!dmabuf))
 		return;
 
+	dma_resv_assert_held(dmabuf->resv);
+
 	BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
 	BUG_ON(dmabuf->vmapping_counter == 0);
 	BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
-- 
2.37.3

[PATCH v7 16/21] dma-buf: Move dma_buf_attach() to dynamic locking specification

[Dmitry Osipenko]

Move dma-buf attachment API functions to the dynamic locking specification
by taking the reservation lock around the mapping operations. The strict
locking convention prevents deadlock situations for dma-buf importers and
exporters.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 2c4381bb9478..d685a5adb122 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -859,8 +859,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 	    dma_buf_is_dynamic(dmabuf)) {
 		struct sg_table *sgt;
 
+		dma_resv_lock(attach->dmabuf->resv, NULL);
 		if (dma_buf_is_dynamic(attach->dmabuf)) {
-			dma_resv_lock(attach->dmabuf->resv, NULL);
 			ret = dmabuf->ops->pin(attach);
 			if (ret)
 				goto err_unlock;
@@ -873,8 +873,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 			ret = PTR_ERR(sgt);
 			goto err_unpin;
 		}
-		if (dma_buf_is_dynamic(attach->dmabuf))
-			dma_resv_unlock(attach->dmabuf->resv);
+		dma_resv_unlock(attach->dmabuf->resv);
 		attach->sgt = sgt;
 		attach->dir = DMA_BIDIRECTIONAL;
 	}
@@ -890,8 +889,7 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 		dmabuf->ops->unpin(attach);
 
 err_unlock:
-	if (dma_buf_is_dynamic(attach->dmabuf))
-		dma_resv_unlock(attach->dmabuf->resv);
+	dma_resv_unlock(attach->dmabuf->resv);
 
 	dma_buf_detach(dmabuf, attach);
 	return ERR_PTR(ret);
@@ -937,21 +935,19 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
 	if (WARN_ON(!dmabuf || !attach))
 		return;
 
+	dma_resv_lock(attach->dmabuf->resv, NULL);
+
 	if (attach->sgt) {
-		if (dma_buf_is_dynamic(attach->dmabuf))
-			dma_resv_lock(attach->dmabuf->resv, NULL);
 
 		__unmap_dma_buf(attach, attach->sgt, attach->dir);
 
-		if (dma_buf_is_dynamic(attach->dmabuf)) {
+		if (dma_buf_is_dynamic(attach->dmabuf))
 			dmabuf->ops->unpin(attach);
-			dma_resv_unlock(attach->dmabuf->resv);
-		}
 	}
-
-	dma_resv_lock(dmabuf->resv, NULL);
 	list_del(&attach->node);
+
 	dma_resv_unlock(dmabuf->resv);
+
 	if (dmabuf->ops->detach)
 		dmabuf->ops->detach(dmabuf, attach);
 
-- 
2.37.3

[PATCH v7 17/21] dma-buf: Move dma_buf_map_attachment() to dynamic locking specification

[Dmitry Osipenko]

Move dma-buf attachment mapping functions to the dynamic locking
specification by asserting that the reservation lock is held.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index d685a5adb122..f54c649f922a 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1038,8 +1038,7 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf))
 		return ERR_PTR(-EINVAL);
 
-	if (dma_buf_attachment_is_dynamic(attach))
-		dma_resv_assert_held(attach->dmabuf->resv);
+	dma_resv_assert_held(attach->dmabuf->resv);
 
 	if (attach->sgt) {
 		/*
@@ -1054,7 +1053,6 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
 	}
 
 	if (dma_buf_is_dynamic(attach->dmabuf)) {
-		dma_resv_assert_held(attach->dmabuf->resv);
 		if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
 			r = attach->dmabuf->ops->pin(attach);
 			if (r)
@@ -1143,15 +1141,11 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 	if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
 		return;
 
-	if (dma_buf_attachment_is_dynamic(attach))
-		dma_resv_assert_held(attach->dmabuf->resv);
+	dma_resv_assert_held(attach->dmabuf->resv);
 
 	if (attach->sgt == sg_table)
 		return;
 
-	if (dma_buf_is_dynamic(attach->dmabuf))
-		dma_resv_assert_held(attach->dmabuf->resv);
-
 	__unmap_dma_buf(attach, sg_table, direction);
 
 	if (dma_buf_is_dynamic(attach->dmabuf) &&
-- 
2.37.3

[PATCH v7 18/21] dma-buf: Move dma_buf_mmap() to dynamic locking specification

[Dmitry Osipenko]

Move dma_buf_mmap() function to the dynamic locking specification by
taking the reservation lock. Neither of the today's drivers take the
reservation lock within the mmap() callback, hence it's safe to enforce
the locking.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index f54c649f922a..f149b384f4dd 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1390,6 +1390,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
 int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 		 unsigned long pgoff)
 {
+	int ret;
+
 	if (WARN_ON(!dmabuf || !vma))
 		return -EINVAL;
 
@@ -1410,7 +1412,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
 	vma_set_file(vma, dmabuf->file);
 	vma->vm_pgoff = pgoff;
 
-	return dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_lock(dmabuf->resv, NULL);
+	ret = dmabuf->ops->mmap(dmabuf, vma);
+	dma_resv_unlock(dmabuf->resv);
+
+	return ret;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
 
-- 
2.37.3

Re: [PATCH v7 18/21] dma-buf: Move dma_buf_mmap() to dynamic locking specification

[Daniel Vetter]

On Mon, 17 Oct 2022 at 19:25, Dmitry Osipenko
<dmitry.osipenko@collabora.com> wrote:
>
> Move dma_buf_mmap() function to the dynamic locking specification by
> taking the reservation lock. Neither of the today's drivers take the
> reservation lock within the mmap() callback, hence it's safe to enforce
> the locking.
>
> Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
> Acked-by: Christian König <christian.koenig@amd.com>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

Just noticed this while reading code ... this patch seems to have
missed dma_buf_mmap_internal()?

Might be good if at least some drivers gain a dma_resv_assert_held in
that path to make sure we're not quite this bad, together with fixing
this issue.
-Daniel

> ---
>  drivers/dma-buf/dma-buf.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
> index f54c649f922a..f149b384f4dd 100644
> --- a/drivers/dma-buf/dma-buf.c
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -1390,6 +1390,8 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_end_cpu_access, DMA_BUF);
>  int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
>                  unsigned long pgoff)
>  {
> +       int ret;
> +
>         if (WARN_ON(!dmabuf || !vma))
>                 return -EINVAL;
>
> @@ -1410,7 +1412,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
>         vma_set_file(vma, dmabuf->file);
>         vma->vm_pgoff = pgoff;
>
> -       return dmabuf->ops->mmap(dmabuf, vma);
> +       dma_resv_lock(dmabuf->resv, NULL);
> +       ret = dmabuf->ops->mmap(dmabuf, vma);
> +       dma_resv_unlock(dmabuf->resv);
> +
> +       return ret;
>  }
>  EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
>
> --
> 2.37.3
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH v7 18/21] dma-buf: Move dma_buf_mmap() to dynamic locking specification

[Dmitry Osipenko]

On 11/7/22 20:25, Daniel Vetter wrote:
>> Move dma_buf_mmap() function to the dynamic locking specification by
>> taking the reservation lock. Neither of the today's drivers take the
>> reservation lock within the mmap() callback, hence it's safe to enforce
>> the locking.
>>
>> Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
>> Acked-by: Christian König <christian.koenig@amd.com>
>> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> Just noticed this while reading code ... this patch seems to have
> missed dma_buf_mmap_internal()?
> 
> Might be good if at least some drivers gain a dma_resv_assert_held in
> that path to make sure we're not quite this bad, together with fixing
> this issue.

Good catch! I'll prepare the patches.

-- 
Best regards,
Dmitry

[PATCH v7 19/21] dma-buf: Document dynamic locking convention

[Dmitry Osipenko]

Add documentation for the dynamic locking convention. The documentation
tells dma-buf API users when they should take the reservation lock and
when not.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 Documentation/driver-api/dma-buf.rst |  6 +++
 drivers/dma-buf/dma-buf.c            | 64 ++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)

diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index 36a76cbe9095..622b8156d212 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/Documentation/driver-api/dma-buf.rst
@@ -119,6 +119,12 @@ DMA Buffer ioctls
 
 .. kernel-doc:: include/uapi/linux/dma-buf.h
 
+DMA-BUF locking convention
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/dma-buf/dma-buf.c
+   :doc: locking convention
+
 Kernel Functions and Structures Reference
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index f149b384f4dd..f1d968e5bac4 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -795,6 +795,70 @@ static struct sg_table * __map_dma_buf(struct dma_buf_attachment *attach,
 	return sg_table;
 }
 
+/**
+ * DOC: locking convention
+ *
+ * In order to avoid deadlock situations between dma-buf exports and importers,
+ * all dma-buf API users must follow the common dma-buf locking convention.
+ *
+ * Convention for importers
+ *
+ * 1. Importers must hold the dma-buf reservation lock when calling these
+ *    functions:
+ *
+ *     - dma_buf_pin()
+ *     - dma_buf_unpin()
+ *     - dma_buf_map_attachment()
+ *     - dma_buf_unmap_attachment()
+ *     - dma_buf_vmap()
+ *     - dma_buf_vunmap()
+ *
+ * 2. Importers must not hold the dma-buf reservation lock when calling these
+ *    functions:
+ *
+ *     - dma_buf_attach()
+ *     - dma_buf_dynamic_attach()
+ *     - dma_buf_detach()
+ *     - dma_buf_export(
+ *     - dma_buf_fd()
+ *     - dma_buf_get()
+ *     - dma_buf_put()
+ *     - dma_buf_mmap()
+ *     - dma_buf_begin_cpu_access()
+ *     - dma_buf_end_cpu_access()
+ *     - dma_buf_map_attachment_unlocked()
+ *     - dma_buf_unmap_attachment_unlocked()
+ *     - dma_buf_vmap_unlocked()
+ *     - dma_buf_vunmap_unlocked()
+ *
+ * Convention for exporters
+ *
+ * 1. These &dma_buf_ops callbacks are invoked with unlocked dma-buf
+ *    reservation and exporter can take the lock:
+ *
+ *     - &dma_buf_ops.attach()
+ *     - &dma_buf_ops.detach()
+ *     - &dma_buf_ops.release()
+ *     - &dma_buf_ops.begin_cpu_access()
+ *     - &dma_buf_ops.end_cpu_access()
+ *
+ * 2. These &dma_buf_ops callbacks are invoked with locked dma-buf
+ *    reservation and exporter can't take the lock:
+ *
+ *     - &dma_buf_ops.pin()
+ *     - &dma_buf_ops.unpin()
+ *     - &dma_buf_ops.map_dma_buf()
+ *     - &dma_buf_ops.unmap_dma_buf()
+ *     - &dma_buf_ops.mmap()
+ *     - &dma_buf_ops.vmap()
+ *     - &dma_buf_ops.vunmap()
+ *
+ * 3. Exporters must hold the dma-buf reservation lock when calling these
+ *    functions:
+ *
+ *     - dma_buf_move_notify()
+ */
+
 /**
  * dma_buf_dynamic_attach - Add the device to dma_buf's attachments list
  * @dmabuf:		[in]	buffer to attach device to.
-- 
2.37.3

[PATCH v7 20/21] media: videobuf2: Stop using internal dma-buf lock

[Dmitry Osipenko]

All drivers that use dma-bufs have been moved to the updated locking
specification and now dma-buf reservation is guaranteed to be locked
by importers during the mapping operations. There is no need to take
the internal dma-buf lock anymore. Remove locking from the videobuf2
memory allocators.

Acked-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/media/common/videobuf2/videobuf2-dma-contig.c | 11 +----------
 drivers/media/common/videobuf2/videobuf2-dma-sg.c     | 11 +----------
 drivers/media/common/videobuf2/videobuf2-vmalloc.c    | 11 +----------
 3 files changed, 3 insertions(+), 30 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index 79f4d8301fbb..555bd40fa472 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -382,18 +382,12 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 	struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 {
 	struct vb2_dc_attachment *attach = db_attach->priv;
-	/* stealing dmabuf mutex to serialize map/unmap operations */
-	struct mutex *lock = &db_attach->dmabuf->lock;
 	struct sg_table *sgt;
 
-	mutex_lock(lock);
-
 	sgt = &attach->sgt;
 	/* return previously mapped sg table */
-	if (attach->dma_dir == dma_dir) {
-		mutex_unlock(lock);
+	if (attach->dma_dir == dma_dir)
 		return sgt;
-	}
 
 	/* release any previous cache */
 	if (attach->dma_dir != DMA_NONE) {
@@ -409,14 +403,11 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 	if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,
 			    DMA_ATTR_SKIP_CPU_SYNC)) {
 		pr_err("failed to map scatterlist\n");
-		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
 	}
 
 	attach->dma_dir = dma_dir;
 
-	mutex_unlock(lock);
-
 	return sgt;
 }
 
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 36ecdea8d707..36981a5b5c53 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -424,18 +424,12 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
 	struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 {
 	struct vb2_dma_sg_attachment *attach = db_attach->priv;
-	/* stealing dmabuf mutex to serialize map/unmap operations */
-	struct mutex *lock = &db_attach->dmabuf->lock;
 	struct sg_table *sgt;
 
-	mutex_lock(lock);
-
 	sgt = &attach->sgt;
 	/* return previously mapped sg table */
-	if (attach->dma_dir == dma_dir) {
-		mutex_unlock(lock);
+	if (attach->dma_dir == dma_dir)
 		return sgt;
-	}
 
 	/* release any previous cache */
 	if (attach->dma_dir != DMA_NONE) {
@@ -446,14 +440,11 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
 	/* mapping to the client with new direction */
 	if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
 		pr_err("failed to map scatterlist\n");
-		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
 	}
 
 	attach->dma_dir = dma_dir;
 
-	mutex_unlock(lock);
-
 	return sgt;
 }
 
diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
index 7831bf545874..41db707e43a4 100644
--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
@@ -267,18 +267,12 @@ static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
 	struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 {
 	struct vb2_vmalloc_attachment *attach = db_attach->priv;
-	/* stealing dmabuf mutex to serialize map/unmap operations */
-	struct mutex *lock = &db_attach->dmabuf->lock;
 	struct sg_table *sgt;
 
-	mutex_lock(lock);
-
 	sgt = &attach->sgt;
 	/* return previously mapped sg table */
-	if (attach->dma_dir == dma_dir) {
-		mutex_unlock(lock);
+	if (attach->dma_dir == dma_dir)
 		return sgt;
-	}
 
 	/* release any previous cache */
 	if (attach->dma_dir != DMA_NONE) {
@@ -289,14 +283,11 @@ static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
 	/* mapping to the client with new direction */
 	if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 0)) {
 		pr_err("failed to map scatterlist\n");
-		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
 	}
 
 	attach->dma_dir = dma_dir;
 
-	mutex_unlock(lock);
-
 	return sgt;
 }
 
-- 
2.37.3

[PATCH v7 21/21] dma-buf: Remove obsoleted internal lock

[Dmitry Osipenko]

The internal dma-buf lock isn't needed anymore because the updated
locking specification claims that dma-buf reservation must be locked
by importers, and thus, the internal data is already protected by the
reservation lock. Remove the obsoleted internal lock.

Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/dma-buf/dma-buf.c | 14 ++++----------
 include/linux/dma-buf.h   |  9 ---------
 2 files changed, 4 insertions(+), 19 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index f1d968e5bac4..7663c4e784b6 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -657,7 +657,6 @@ struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
 
 	dmabuf->file = file;
 
-	mutex_init(&dmabuf->lock);
 	INIT_LIST_HEAD(&dmabuf->attachments);
 
 	mutex_lock(&db_list.lock);
@@ -1503,7 +1502,7 @@ EXPORT_SYMBOL_NS_GPL(dma_buf_mmap, DMA_BUF);
 int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 {
 	struct iosys_map ptr;
-	int ret = 0;
+	int ret;
 
 	iosys_map_clear(map);
 
@@ -1515,28 +1514,25 @@ int dma_buf_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	if (!dmabuf->ops->vmap)
 		return -EINVAL;
 
-	mutex_lock(&dmabuf->lock);
 	if (dmabuf->vmapping_counter) {
 		dmabuf->vmapping_counter++;
 		BUG_ON(iosys_map_is_null(&dmabuf->vmap_ptr));
 		*map = dmabuf->vmap_ptr;
-		goto out_unlock;
+		return 0;
 	}
 
 	BUG_ON(iosys_map_is_set(&dmabuf->vmap_ptr));
 
 	ret = dmabuf->ops->vmap(dmabuf, &ptr);
 	if (WARN_ON_ONCE(ret))
-		goto out_unlock;
+		return ret;
 
 	dmabuf->vmap_ptr = ptr;
 	dmabuf->vmapping_counter = 1;
 
 	*map = dmabuf->vmap_ptr;
 
-out_unlock:
-	mutex_unlock(&dmabuf->lock);
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vmap, DMA_BUF);
 
@@ -1583,13 +1579,11 @@ void dma_buf_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
 	BUG_ON(dmabuf->vmapping_counter == 0);
 	BUG_ON(!iosys_map_is_equal(&dmabuf->vmap_ptr, map));
 
-	mutex_lock(&dmabuf->lock);
 	if (--dmabuf->vmapping_counter == 0) {
 		if (dmabuf->ops->vunmap)
 			dmabuf->ops->vunmap(dmabuf, map);
 		iosys_map_clear(&dmabuf->vmap_ptr);
 	}
-	mutex_unlock(&dmabuf->lock);
 }
 EXPORT_SYMBOL_NS_GPL(dma_buf_vunmap, DMA_BUF);
 
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index f11b5bbc2f37..6fa8d4e29719 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -326,15 +326,6 @@ struct dma_buf {
 	/** @ops: dma_buf_ops associated with this buffer object. */
 	const struct dma_buf_ops *ops;
 
-	/**
-	 * @lock:
-	 *
-	 * Used internally to serialize list manipulation, attach/detach and
-	 * vmap/unmap. Note that in many cases this is superseeded by
-	 * dma_resv_lock() on @resv.
-	 */
-	struct mutex lock;
-
 	/**
 	 * @vmapping_counter:
 	 *
-- 
2.37.3

Re: [PATCH v7 00/21] Move all drivers to a common dma-buf locking convention

[Dmitry Osipenko]

On 10/17/22 20:22, Dmitry Osipenko wrote:
> Hello,
> 
> This series moves all drivers to a dynamic dma-buf locking specification.
> From now on all dma-buf importers are made responsible for holding
> dma-buf's reservation lock around all operations performed over dma-bufs
> in accordance to the locking specification. This allows us to utilize
> reservation lock more broadly around kernel without fearing of a potential
> deadlocks.
> 
> This patchset passes all i915 selftests. It was also tested using VirtIO,
> Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases
> of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate),
> which covers majority of kernel drivers since rest of the drivers share
> same or similar code paths.
> 
> Changelog:
> 
> v7: - Rebased on top of recent drm-misc-next.
> 
>     - Added ack from Jason Gunthorpe to the RDMA patch.
> 
>     - Added iosys_map_clear() to dma_buf_vmap_unlocked(), making it fully
>       consistent with dma_buf_vmap().
> 
> v6: - Added r-b from Michael Ruhl to the i915 patch.
> 
>     - Added acks from Sumit Semwal and updated commit message of the
>       "Move dma_buf_vmap() to dynamic locking specification" patch like
>       was suggested by Sumit.
> 
>     - Added "!dmabuf" check to dma_buf_vmap_unlocked() to match the locked
>       variant of the function, for consistency.
> 
> v5: - Added acks and r-bs that were given to v4.
> 
>     - Changed i915 preparation patch like was suggested by Michael Ruhl.
>       The scope of reservation locking is smaller now.
> 
> v4: - Added dma_buf_mmap() to the "locking convention" documentation,
>       which was missed by accident in v3.
> 
>     - Added acks from Christian König, Tomasz Figa and Hans Verkuil that
>       they gave to couple v3 patches.
> 
>     - Dropped the "_unlocked" postfix from function names that don't have
>       the locked variant, as was requested by Christian König.
> 
>     - Factored out the per-driver preparations into separate patches
>       to ease reviewing of the changes, which is now doable without the
>       global dma-buf functions renaming.
> 
>     - Factored out the dynamic locking convention enforcements into separate
>       patches which add the final dma_resv_assert_held(dmabuf->resv) to the
>       dma-buf API functions.
> 
> v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
>       into aseparate patches, like was suggested by Christian König.
> 
>     - Corrected and factored out dma-buf locking documentation into
>       a separate patch, like was suggested by Christian König.
> 
>     - Intel driver dropped the reservation locking fews days ago from
>       its BO-release code path, but we need that locking for the imported
>       GEMs because in the end that code path unmaps the imported GEM.
>       So I added back the locking needed by the imported GEMs, updating
>       the "dma-buf attachment locking specification" patch appropriately.
> 
>     - Tested Nouveau+Intel dma-buf import/export combo.
> 
>     - Tested udmabuf import to i915/Nouveau/AMDGPU.
> 
>     - Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed
>       to switch to locked dma-buf vmapping in the drm/gem: Take reservation
>       lock for vmap/vunmap operations" patch. In a result invalidated the
>       Christian's r-b that he gave to v2.
> 
>     - Added locked dma-buf vmap/vunmap functions that are needed for fixing
>       vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
>       I actually had this change stashed for the drm-shmem shrinker patchset,
>       but then realized that it's already needed by the dma-buf patches.
>       Also improved my tests to better cover these code paths.
> 
> v2: - Changed locking specification to avoid problems with a cross-driver
>       ww locking, like was suggested by Christian König. Now the attach/detach
>       callbacks are invoked without the held lock and exporter should take the
>       lock.
> 
>     - Added "locking convention" documentation that explains which dma-buf
>       functions and callbacks are locked/unlocked for importers and exporters,
>       which was requested by Christian König.
> 
>     - Added ack from Tomasz Figa to the V4L patches that he gave to v1.
> 
> Dmitry Osipenko (21):
>   dma-buf: Add unlocked variant of vmapping functions
>   dma-buf: Add unlocked variant of attachment-mapping functions
>   drm/gem: Take reservation lock for vmap/vunmap operations
>   drm/prime: Prepare to dynamic dma-buf locking specification
>   drm/armada: Prepare to dynamic dma-buf locking specification
>   drm/i915: Prepare to dynamic dma-buf locking specification
>   drm/omapdrm: Prepare to dynamic dma-buf locking specification
>   drm/tegra: Prepare to dynamic dma-buf locking specification
>   drm/etnaviv: Prepare to dynamic dma-buf locking specification
>   RDMA/umem: Prepare to dynamic dma-buf locking specification
>   misc: fastrpc: Prepare to dynamic dma-buf locking specification
>   xen/gntdev: Prepare to dynamic dma-buf locking specification
>   media: videobuf2: Prepare to dynamic dma-buf locking specification
>   media: tegra-vde: Prepare to dynamic dma-buf locking specification
>   dma-buf: Move dma_buf_vmap() to dynamic locking specification
>   dma-buf: Move dma_buf_attach() to dynamic locking specification
>   dma-buf: Move dma_buf_map_attachment() to dynamic locking
>     specification
>   dma-buf: Move dma_buf_mmap() to dynamic locking specification
>   dma-buf: Document dynamic locking convention
>   media: videobuf2: Stop using internal dma-buf lock
>   dma-buf: Remove obsoleted internal lock
> 
>  Documentation/driver-api/dma-buf.rst          |   6 +
>  drivers/dma-buf/dma-buf.c                     | 216 +++++++++++++++---
>  drivers/gpu/drm/armada/armada_gem.c           |   8 +-
>  drivers/gpu/drm/drm_client.c                  |   4 +-
>  drivers/gpu/drm/drm_gem.c                     |  24 ++
>  drivers/gpu/drm/drm_gem_dma_helper.c          |   6 +-
>  drivers/gpu/drm/drm_gem_framebuffer_helper.c  |   6 +-
>  drivers/gpu/drm/drm_gem_ttm_helper.c          |   9 +-
>  drivers/gpu/drm/drm_prime.c                   |   6 +-
>  drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c   |   2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    |   2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_object.c    |  14 ++
>  .../drm/i915/gem/selftests/i915_gem_dmabuf.c  |  16 +-
>  drivers/gpu/drm/lima/lima_sched.c             |   4 +-
>  drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c     |   4 +-
>  drivers/gpu/drm/panfrost/panfrost_dump.c      |   4 +-
>  drivers/gpu/drm/panfrost/panfrost_perfcnt.c   |   6 +-
>  drivers/gpu/drm/qxl/qxl_object.c              |  17 +-
>  drivers/gpu/drm/qxl/qxl_prime.c               |   4 +-
>  drivers/gpu/drm/tegra/gem.c                   |  17 +-
>  drivers/infiniband/core/umem_dmabuf.c         |   7 +-
>  .../common/videobuf2/videobuf2-dma-contig.c   |  22 +-
>  .../media/common/videobuf2/videobuf2-dma-sg.c |  19 +-
>  .../common/videobuf2/videobuf2-vmalloc.c      |  17 +-
>  .../platform/nvidia/tegra-vde/dmabuf-cache.c  |   6 +-
>  drivers/misc/fastrpc.c                        |   6 +-
>  drivers/xen/gntdev-dmabuf.c                   |   8 +-
>  include/drm/drm_gem.h                         |   3 +
>  include/linux/dma-buf.h                       |  17 +-
>  29 files changed, 325 insertions(+), 155 deletions(-)
> 

Applied to drm-misc-next

-- 
Best regards,
Dmitry

Re: [PATCH v7 00/21] Move all drivers to a common dma-buf locking convention

[Christian König]

Am 18.10.22 um 01:07 schrieb Dmitry Osipenko:
> On 10/17/22 20:22, Dmitry Osipenko wrote:
>> Hello,
>>
>> This series moves all drivers to a dynamic dma-buf locking specification.
>>  From now on all dma-buf importers are made responsible for holding
>> dma-buf's reservation lock around all operations performed over dma-bufs
>> in accordance to the locking specification. This allows us to utilize
>> reservation lock more broadly around kernel without fearing of a potential
>> deadlocks.
>>
>> This patchset passes all i915 selftests. It was also tested using VirtIO,
>> Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested cases
>> of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where appropriate),
>> which covers majority of kernel drivers since rest of the drivers share
>> same or similar code paths.
>>
>> Changelog:
>>
>> v7: - Rebased on top of recent drm-misc-next.
>>
>>      - Added ack from Jason Gunthorpe to the RDMA patch.
>>
>>      - Added iosys_map_clear() to dma_buf_vmap_unlocked(), making it fully
>>        consistent with dma_buf_vmap().
>>
>> v6: - Added r-b from Michael Ruhl to the i915 patch.
>>
>>      - Added acks from Sumit Semwal and updated commit message of the
>>        "Move dma_buf_vmap() to dynamic locking specification" patch like
>>        was suggested by Sumit.
>>
>>      - Added "!dmabuf" check to dma_buf_vmap_unlocked() to match the locked
>>        variant of the function, for consistency.
>>
>> v5: - Added acks and r-bs that were given to v4.
>>
>>      - Changed i915 preparation patch like was suggested by Michael Ruhl.
>>        The scope of reservation locking is smaller now.
>>
>> v4: - Added dma_buf_mmap() to the "locking convention" documentation,
>>        which was missed by accident in v3.
>>
>>      - Added acks from Christian König, Tomasz Figa and Hans Verkuil that
>>        they gave to couple v3 patches.
>>
>>      - Dropped the "_unlocked" postfix from function names that don't have
>>        the locked variant, as was requested by Christian König.
>>
>>      - Factored out the per-driver preparations into separate patches
>>        to ease reviewing of the changes, which is now doable without the
>>        global dma-buf functions renaming.
>>
>>      - Factored out the dynamic locking convention enforcements into separate
>>        patches which add the final dma_resv_assert_held(dmabuf->resv) to the
>>        dma-buf API functions.
>>
>> v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
>>        into aseparate patches, like was suggested by Christian König.
>>
>>      - Corrected and factored out dma-buf locking documentation into
>>        a separate patch, like was suggested by Christian König.
>>
>>      - Intel driver dropped the reservation locking fews days ago from
>>        its BO-release code path, but we need that locking for the imported
>>        GEMs because in the end that code path unmaps the imported GEM.
>>        So I added back the locking needed by the imported GEMs, updating
>>        the "dma-buf attachment locking specification" patch appropriately.
>>
>>      - Tested Nouveau+Intel dma-buf import/export combo.
>>
>>      - Tested udmabuf import to i915/Nouveau/AMDGPU.
>>
>>      - Fixed few places in Etnaviv, Panfrost and Lima drivers that I missed
>>        to switch to locked dma-buf vmapping in the drm/gem: Take reservation
>>        lock for vmap/vunmap operations" patch. In a result invalidated the
>>        Christian's r-b that he gave to v2.
>>
>>      - Added locked dma-buf vmap/vunmap functions that are needed for fixing
>>        vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
>>        I actually had this change stashed for the drm-shmem shrinker patchset,
>>        but then realized that it's already needed by the dma-buf patches.
>>        Also improved my tests to better cover these code paths.
>>
>> v2: - Changed locking specification to avoid problems with a cross-driver
>>        ww locking, like was suggested by Christian König. Now the attach/detach
>>        callbacks are invoked without the held lock and exporter should take the
>>        lock.
>>
>>      - Added "locking convention" documentation that explains which dma-buf
>>        functions and callbacks are locked/unlocked for importers and exporters,
>>        which was requested by Christian König.
>>
>>      - Added ack from Tomasz Figa to the V4L patches that he gave to v1.
>>
>> Dmitry Osipenko (21):
>>    dma-buf: Add unlocked variant of vmapping functions
>>    dma-buf: Add unlocked variant of attachment-mapping functions
>>    drm/gem: Take reservation lock for vmap/vunmap operations
>>    drm/prime: Prepare to dynamic dma-buf locking specification
>>    drm/armada: Prepare to dynamic dma-buf locking specification
>>    drm/i915: Prepare to dynamic dma-buf locking specification
>>    drm/omapdrm: Prepare to dynamic dma-buf locking specification
>>    drm/tegra: Prepare to dynamic dma-buf locking specification
>>    drm/etnaviv: Prepare to dynamic dma-buf locking specification
>>    RDMA/umem: Prepare to dynamic dma-buf locking specification
>>    misc: fastrpc: Prepare to dynamic dma-buf locking specification
>>    xen/gntdev: Prepare to dynamic dma-buf locking specification
>>    media: videobuf2: Prepare to dynamic dma-buf locking specification
>>    media: tegra-vde: Prepare to dynamic dma-buf locking specification
>>    dma-buf: Move dma_buf_vmap() to dynamic locking specification
>>    dma-buf: Move dma_buf_attach() to dynamic locking specification
>>    dma-buf: Move dma_buf_map_attachment() to dynamic locking
>>      specification
>>    dma-buf: Move dma_buf_mmap() to dynamic locking specification
>>    dma-buf: Document dynamic locking convention
>>    media: videobuf2: Stop using internal dma-buf lock
>>    dma-buf: Remove obsoleted internal lock
>>
>>   Documentation/driver-api/dma-buf.rst          |   6 +
>>   drivers/dma-buf/dma-buf.c                     | 216 +++++++++++++++---
>>   drivers/gpu/drm/armada/armada_gem.c           |   8 +-
>>   drivers/gpu/drm/drm_client.c                  |   4 +-
>>   drivers/gpu/drm/drm_gem.c                     |  24 ++
>>   drivers/gpu/drm/drm_gem_dma_helper.c          |   6 +-
>>   drivers/gpu/drm/drm_gem_framebuffer_helper.c  |   6 +-
>>   drivers/gpu/drm/drm_gem_ttm_helper.c          |   9 +-
>>   drivers/gpu/drm/drm_prime.c                   |   6 +-
>>   drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c   |   2 +-
>>   drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    |   2 +-
>>   drivers/gpu/drm/i915/gem/i915_gem_object.c    |  14 ++
>>   .../drm/i915/gem/selftests/i915_gem_dmabuf.c  |  16 +-
>>   drivers/gpu/drm/lima/lima_sched.c             |   4 +-
>>   drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c     |   4 +-
>>   drivers/gpu/drm/panfrost/panfrost_dump.c      |   4 +-
>>   drivers/gpu/drm/panfrost/panfrost_perfcnt.c   |   6 +-
>>   drivers/gpu/drm/qxl/qxl_object.c              |  17 +-
>>   drivers/gpu/drm/qxl/qxl_prime.c               |   4 +-
>>   drivers/gpu/drm/tegra/gem.c                   |  17 +-
>>   drivers/infiniband/core/umem_dmabuf.c         |   7 +-
>>   .../common/videobuf2/videobuf2-dma-contig.c   |  22 +-
>>   .../media/common/videobuf2/videobuf2-dma-sg.c |  19 +-
>>   .../common/videobuf2/videobuf2-vmalloc.c      |  17 +-
>>   .../platform/nvidia/tegra-vde/dmabuf-cache.c  |   6 +-
>>   drivers/misc/fastrpc.c                        |   6 +-
>>   drivers/xen/gntdev-dmabuf.c                   |   8 +-
>>   include/drm/drm_gem.h                         |   3 +
>>   include/linux/dma-buf.h                       |  17 +-
>>   29 files changed, 325 insertions(+), 155 deletions(-)
>>
> Applied to drm-misc-next

Finally! Fingers crossed that all corner cases where fixed during the 
review.

But if anything shows up feel free to loop me in to help fixing things.

Thanks a lot for doing this,
Christian.

Re: [PATCH v7 00/21] Move all drivers to a common dma-buf locking convention

[Dmitry Osipenko]

On 10/18/22 14:34, Christian König wrote:
> Am 18.10.22 um 01:07 schrieb Dmitry Osipenko:
>> On 10/17/22 20:22, Dmitry Osipenko wrote:
>>> Hello,
>>>
>>> This series moves all drivers to a dynamic dma-buf locking
>>> specification.
>>>  From now on all dma-buf importers are made responsible for holding
>>> dma-buf's reservation lock around all operations performed over dma-bufs
>>> in accordance to the locking specification. This allows us to utilize
>>> reservation lock more broadly around kernel without fearing of a
>>> potential
>>> deadlocks.
>>>
>>> This patchset passes all i915 selftests. It was also tested using
>>> VirtIO,
>>> Panfrost, Lima, Tegra, udmabuf, AMDGPU and Nouveau drivers. I tested
>>> cases
>>> of display+GPU, display+V4L and GPU+V4L dma-buf sharing (where
>>> appropriate),
>>> which covers majority of kernel drivers since rest of the drivers share
>>> same or similar code paths.
>>>
>>> Changelog:
>>>
>>> v7: - Rebased on top of recent drm-misc-next.
>>>
>>>      - Added ack from Jason Gunthorpe to the RDMA patch.
>>>
>>>      - Added iosys_map_clear() to dma_buf_vmap_unlocked(), making it
>>> fully
>>>        consistent with dma_buf_vmap().
>>>
>>> v6: - Added r-b from Michael Ruhl to the i915 patch.
>>>
>>>      - Added acks from Sumit Semwal and updated commit message of the
>>>        "Move dma_buf_vmap() to dynamic locking specification" patch like
>>>        was suggested by Sumit.
>>>
>>>      - Added "!dmabuf" check to dma_buf_vmap_unlocked() to match the
>>> locked
>>>        variant of the function, for consistency.
>>>
>>> v5: - Added acks and r-bs that were given to v4.
>>>
>>>      - Changed i915 preparation patch like was suggested by Michael
>>> Ruhl.
>>>        The scope of reservation locking is smaller now.
>>>
>>> v4: - Added dma_buf_mmap() to the "locking convention" documentation,
>>>        which was missed by accident in v3.
>>>
>>>      - Added acks from Christian König, Tomasz Figa and Hans Verkuil
>>> that
>>>        they gave to couple v3 patches.
>>>
>>>      - Dropped the "_unlocked" postfix from function names that don't
>>> have
>>>        the locked variant, as was requested by Christian König.
>>>
>>>      - Factored out the per-driver preparations into separate patches
>>>        to ease reviewing of the changes, which is now doable without the
>>>        global dma-buf functions renaming.
>>>
>>>      - Factored out the dynamic locking convention enforcements into
>>> separate
>>>        patches which add the final dma_resv_assert_held(dmabuf->resv)
>>> to the
>>>        dma-buf API functions.
>>>
>>> v3: - Factored out dma_buf_mmap_unlocked() and attachment functions
>>>        into aseparate patches, like was suggested by Christian König.
>>>
>>>      - Corrected and factored out dma-buf locking documentation into
>>>        a separate patch, like was suggested by Christian König.
>>>
>>>      - Intel driver dropped the reservation locking fews days ago from
>>>        its BO-release code path, but we need that locking for the
>>> imported
>>>        GEMs because in the end that code path unmaps the imported GEM.
>>>        So I added back the locking needed by the imported GEMs, updating
>>>        the "dma-buf attachment locking specification" patch
>>> appropriately.
>>>
>>>      - Tested Nouveau+Intel dma-buf import/export combo.
>>>
>>>      - Tested udmabuf import to i915/Nouveau/AMDGPU.
>>>
>>>      - Fixed few places in Etnaviv, Panfrost and Lima drivers that I
>>> missed
>>>        to switch to locked dma-buf vmapping in the drm/gem: Take
>>> reservation
>>>        lock for vmap/vunmap operations" patch. In a result
>>> invalidated the
>>>        Christian's r-b that he gave to v2.
>>>
>>>      - Added locked dma-buf vmap/vunmap functions that are needed for
>>> fixing
>>>        vmappping of Etnaviv, Panfrost and Lima drivers mentioned above.
>>>        I actually had this change stashed for the drm-shmem shrinker
>>> patchset,
>>>        but then realized that it's already needed by the dma-buf
>>> patches.
>>>        Also improved my tests to better cover these code paths.
>>>
>>> v2: - Changed locking specification to avoid problems with a
>>> cross-driver
>>>        ww locking, like was suggested by Christian König. Now the
>>> attach/detach
>>>        callbacks are invoked without the held lock and exporter
>>> should take the
>>>        lock.
>>>
>>>      - Added "locking convention" documentation that explains which
>>> dma-buf
>>>        functions and callbacks are locked/unlocked for importers and
>>> exporters,
>>>        which was requested by Christian König.
>>>
>>>      - Added ack from Tomasz Figa to the V4L patches that he gave to v1.
>>>
>>> Dmitry Osipenko (21):
>>>    dma-buf: Add unlocked variant of vmapping functions
>>>    dma-buf: Add unlocked variant of attachment-mapping functions
>>>    drm/gem: Take reservation lock for vmap/vunmap operations
>>>    drm/prime: Prepare to dynamic dma-buf locking specification
>>>    drm/armada: Prepare to dynamic dma-buf locking specification
>>>    drm/i915: Prepare to dynamic dma-buf locking specification
>>>    drm/omapdrm: Prepare to dynamic dma-buf locking specification
>>>    drm/tegra: Prepare to dynamic dma-buf locking specification
>>>    drm/etnaviv: Prepare to dynamic dma-buf locking specification
>>>    RDMA/umem: Prepare to dynamic dma-buf locking specification
>>>    misc: fastrpc: Prepare to dynamic dma-buf locking specification
>>>    xen/gntdev: Prepare to dynamic dma-buf locking specification
>>>    media: videobuf2: Prepare to dynamic dma-buf locking specification
>>>    media: tegra-vde: Prepare to dynamic dma-buf locking specification
>>>    dma-buf: Move dma_buf_vmap() to dynamic locking specification
>>>    dma-buf: Move dma_buf_attach() to dynamic locking specification
>>>    dma-buf: Move dma_buf_map_attachment() to dynamic locking
>>>      specification
>>>    dma-buf: Move dma_buf_mmap() to dynamic locking specification
>>>    dma-buf: Document dynamic locking convention
>>>    media: videobuf2: Stop using internal dma-buf lock
>>>    dma-buf: Remove obsoleted internal lock
>>>
>>>   Documentation/driver-api/dma-buf.rst          |   6 +
>>>   drivers/dma-buf/dma-buf.c                     | 216 +++++++++++++++---
>>>   drivers/gpu/drm/armada/armada_gem.c           |   8 +-
>>>   drivers/gpu/drm/drm_client.c                  |   4 +-
>>>   drivers/gpu/drm/drm_gem.c                     |  24 ++
>>>   drivers/gpu/drm/drm_gem_dma_helper.c          |   6 +-
>>>   drivers/gpu/drm/drm_gem_framebuffer_helper.c  |   6 +-
>>>   drivers/gpu/drm/drm_gem_ttm_helper.c          |   9 +-
>>>   drivers/gpu/drm/drm_prime.c                   |   6 +-
>>>   drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c   |   2 +-
>>>   drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c    |   2 +-
>>>   drivers/gpu/drm/i915/gem/i915_gem_object.c    |  14 ++
>>>   .../drm/i915/gem/selftests/i915_gem_dmabuf.c  |  16 +-
>>>   drivers/gpu/drm/lima/lima_sched.c             |   4 +-
>>>   drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c     |   4 +-
>>>   drivers/gpu/drm/panfrost/panfrost_dump.c      |   4 +-
>>>   drivers/gpu/drm/panfrost/panfrost_perfcnt.c   |   6 +-
>>>   drivers/gpu/drm/qxl/qxl_object.c              |  17 +-
>>>   drivers/gpu/drm/qxl/qxl_prime.c               |   4 +-
>>>   drivers/gpu/drm/tegra/gem.c                   |  17 +-
>>>   drivers/infiniband/core/umem_dmabuf.c         |   7 +-
>>>   .../common/videobuf2/videobuf2-dma-contig.c   |  22 +-
>>>   .../media/common/videobuf2/videobuf2-dma-sg.c |  19 +-
>>>   .../common/videobuf2/videobuf2-vmalloc.c      |  17 +-
>>>   .../platform/nvidia/tegra-vde/dmabuf-cache.c  |   6 +-
>>>   drivers/misc/fastrpc.c                        |   6 +-
>>>   drivers/xen/gntdev-dmabuf.c                   |   8 +-
>>>   include/drm/drm_gem.h                         |   3 +
>>>   include/linux/dma-buf.h                       |  17 +-
>>>   29 files changed, 325 insertions(+), 155 deletions(-)
>>>
>> Applied to drm-misc-next
> 
> Finally! Fingers crossed that all corner cases where fixed during the
> review.
> 
> But if anything shows up feel free to loop me in to help fixing things.
> 
> Thanks a lot for doing this,
> Christian.

I'll ping you if anything will show up. Thank you!

-- 
Best regards,
Dmitry