On Fri, Jun 22, 2018 at 04:11:00PM +0200, Christian König wrote:

Add function variants which can be called with the reservation lock already held.

v2: reordered, add lockdep asserts, fix kerneldoc

Signed-off-by: Christian König christian.koenig@amd.com

drivers/dma-buf/dma-buf.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 5 +++++ 2 files changed, 62 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 852a3928ee71..dc94e76e2e2a 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -606,6 +606,40 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) } EXPORT_SYMBOL_GPL(dma_buf_detach);

+/**

• • dma_buf_map_attachment_locked - Maps the buffer into _device_ address space
• • with the reservation lock held. Is a wrapper for map_dma_buf() of the

This here looks mangled (and the blank line wreaks the resulting html). With that fixed.

Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

• • Returns the scatterlist table of the attachment;
• • dma_buf_ops.
• • @attach: [in] attachment whose scatterlist is to be returned
• • @direction: [in] direction of DMA transfer
• • Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
• • on error. May return -EINTR if it is interrupted by a signal.
• • A mapping must be unmapped by using dma_buf_unmap_attachment_locked(). Note
• • that the underlying backing storage is pinned for as long as a mapping
• • exists, therefore users/importers should not hold onto a mapping for undue
• • amounts of time.
• */

+struct sg_table * +dma_buf_map_attachment_locked(struct dma_buf_attachment *attach,

• 	      enum dma_data_direction direction)
  

+{

• struct sg_table *sg_table;
• might_sleep();
• reservation_object_assert_held(attach->dmabuf->resv);
• sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
• if (!sg_table)

• sg_table = ERR_PTR(-ENOMEM);
  

• return sg_table;

+} +EXPORT_SYMBOL_GPL(dma_buf_map_attachment_locked);

/**

• dma_buf_map_attachment - Returns the scatterlist table of the attachment;
• mapped into _device_ address space. Is a wrapper for map_dma_buf() of the

@@ -639,6 +673,29 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } EXPORT_SYMBOL_GPL(dma_buf_map_attachment);

+/**

• • dma_buf_unmap_attachment_locked - unmaps the buffer with reservation lock
• • held, should deallocate the associated scatterlist. 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
• • This unmaps a DMA mapping for @attached obtained by
• • dma_buf_map_attachment_locked().
• */

+void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *attach,

• 		     struct sg_table *sg_table,
  

• 		     enum dma_data_direction direction)
  

+{

• might_sleep();
• reservation_object_assert_held(attach->dmabuf->resv);
• attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

• 				direction);
  

+} +EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment_locked);

/**

• dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
• deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 991787a03199..a25e754ae2f7 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -384,8 +384,13 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags); struct dma_buf *dma_buf_get(int fd); void dma_buf_put(struct dma_buf *dmabuf);

+struct sg_table *dma_buf_map_attachment_locked(struct dma_buf_attachment *,

• 			       enum dma_data_direction);
  

struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction); +void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *,

• 		     struct sg_table *,
  

• 		     enum dma_data_direction);
  

void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, enum dma_data_direction); int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, -- 2.14.1

On 06/22/2018 10:11 PM, Christian König wrote:

Add function variants which can be called with the reservation lock already held.

v2: reordered, add lockdep asserts, fix kerneldoc

Signed-off-by: Christian König christian.koenig@amd.com

drivers/dma-buf/dma-buf.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/dma-buf.h | 5 +++++ 2 files changed, 62 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 852a3928ee71..dc94e76e2e2a 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -606,6 +606,40 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) } EXPORT_SYMBOL_GPL(dma_buf_detach);

+/**

• • dma_buf_map_attachment_locked - Maps the buffer into _device_ address space
• • with the reservation lock held. Is a wrapper for map_dma_buf() of the
• • Returns the scatterlist table of the attachment;
• • dma_buf_ops.
• • @attach: [in] attachment whose scatterlist is to be returned
• • @direction: [in] direction of DMA transfer
• • Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
• • on error. May return -EINTR if it is interrupted by a signal.
• • A mapping must be unmapped by using dma_buf_unmap_attachment_locked(). Note
• • that the underlying backing storage is pinned for as long as a mapping
• • exists, therefore users/importers should not hold onto a mapping for undue
• • amounts of time.
• */

+struct sg_table * +dma_buf_map_attachment_locked(struct dma_buf_attachment *attach,

• 	      enum dma_data_direction direction)
  

+{

• struct sg_table *sg_table;

Perhaps better to add some error check, like dma_buf_map_attachment()

WARN_ON(!attach || !attach->dmabuf)

Apart from that, it's Reviewed-by: Junwei Zhang Jerry.Zhang@amd.com

Jerry

• might_sleep();
• reservation_object_assert_held(attach->dmabuf->resv);
• sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
• if (!sg_table)

• sg_table = ERR_PTR(-ENOMEM);
  

• return sg_table;

+} +EXPORT_SYMBOL_GPL(dma_buf_map_attachment_locked);

• /**
  • dma_buf_map_attachment - Returns the scatterlist table of the attachment;
  • mapped into _device_ address space. Is a wrapper for map_dma_buf() of the

@@ -639,6 +673,29 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } EXPORT_SYMBOL_GPL(dma_buf_map_attachment);

+/**

• • dma_buf_unmap_attachment_locked - unmaps the buffer with reservation lock
• • held, should deallocate the associated scatterlist. 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
• • This unmaps a DMA mapping for @attached obtained by
• • dma_buf_map_attachment_locked().
• */

+void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *attach,

• 		     struct sg_table *sg_table,
  

• 		     enum dma_data_direction direction)
  

+{

• might_sleep();
• reservation_object_assert_held(attach->dmabuf->resv);
• attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

• 				direction);
  

+} +EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment_locked);

• /**
  • dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
  • deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 991787a03199..a25e754ae2f7 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -384,8 +384,13 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags); struct dma_buf *dma_buf_get(int fd); void dma_buf_put(struct dma_buf *dmabuf);

+struct sg_table *dma_buf_map_attachment_locked(struct dma_buf_attachment *,

• 			       enum dma_data_direction);
  

  struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction);

+void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *,

• 		     struct sg_table *,
  

• 		     enum dma_data_direction);
  

  void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, enum dma_data_direction); int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,

On Mon, Jun 25, 2018 at 10:22:31AM +0200, Daniel Vetter wrote:

On Fri, Jun 22, 2018 at 04:11:01PM +0200, Christian König wrote:

...

First step towards unpinned DMA buf operation.

I've checked the DRM drivers to potential locking of the reservation object, but essentially we need to audit all implementations of the dma_buf _ops for this to work.

v2: reordered

Signed-off-by: Christian König christian.koenig@amd.com

Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

Ok I did review drivers a bit, but apparently not well enough by far. i915 CI is unhappy:

https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_9400/fi-whl-u/igt@gem_mma...

So yeah inserting that lock in there isn't the most trivial thing :-/

I kinda assume that other drivers will have similar issues, e.g. omapdrm's use of dev->struct_mutex also very much looks like it'll result in a new locking inversion. -Daniel

...

---

drivers/dma-buf/dma-buf.c | 9 ++++++--- include/linux/dma-buf.h | 4 ++++ 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index dc94e76e2e2a..49f23b791eb8 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -665,7 +665,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL);

• sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);

• reservation_object_lock(attach->dmabuf->resv, NULL);
• sg_table = dma_buf_map_attachment_locked(attach, direction);
• reservation_object_unlock(attach->dmabuf->resv); if (!sg_table) sg_table = ERR_PTR(-ENOMEM);

@@ -715,8 +717,9 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return;

• attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

• 				direction);
  

• reservation_object_lock(attach->dmabuf->resv, NULL);
• dma_buf_unmap_attachment_locked(attach, sg_table, direction);
• reservation_object_unlock(attach->dmabuf->resv);

} EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index a25e754ae2f7..024658d1f22e 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -118,6 +118,8 @@ struct dma_buf_ops { * any other kind of sharing that the exporter might wish to make * available to buffer-users. *

• * This is called with the dmabuf->resv object locked.
  

• *
  

  • Returns:
  • A &sg_table scatter list of or the backing storage of the DMA buffer,

@@ -138,6 +140,8 @@ struct dma_buf_ops { * It should also unpin the backing storage if this is the last mapping * of the DMA buffer, it the exporter supports backing storage * migration.

• *
  

• * This is called with the dmabuf->resv object locked.
  

  */ void (*unmap_dma_buf)(struct dma_buf_attachment *, struct sg_table *,

-- 2.14.1

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

On Tue, Jul 03, 2018 at 01:46:44PM +0200, Christian König wrote:

Am 25.06.2018 um 11:12 schrieb Daniel Vetter:

...

On Mon, Jun 25, 2018 at 10:22:31AM +0200, Daniel Vetter wrote:

...

On Fri, Jun 22, 2018 at 04:11:01PM +0200, Christian König wrote:

...

First step towards unpinned DMA buf operation.

I've checked the DRM drivers to potential locking of the reservation object, but essentially we need to audit all implementations of the dma_buf _ops for this to work.

v2: reordered

Signed-off-by: Christian König christian.koenig@amd.com

Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

Ok I did review drivers a bit, but apparently not well enough by far. i915 CI is unhappy:

https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_9400/fi-whl-u/igt@gem_mma...

So yeah inserting that lock in there isn't the most trivial thing :-/

I kinda assume that other drivers will have similar issues, e.g. omapdrm's use of dev->struct_mutex also very much looks like it'll result in a new locking inversion.

Ah, crap. Already feared that this wouldn't be easy, but yeah that it is as bad as this is rather disappointing.

Thanks for the info, going to keep thinking about how to solve those issues.

Side note: We want to make sure that drivers don't get the reservation_obj locking hierarchy wrong in other places (using dev->struct_mutex is kinda a pre-existing mis-use that we can't wish away retroactively unfortunately). One really important thing is that shrinker vs resv_obj must work with trylocks in the shrinker, so that you can allocate memory while holding reservation objects.

One neat trick to teach lockdep about this would be to have a dummy

if (IS_ENABLED(CONFIG_PROVE_LOCKING)) { ww_mutex_lock(dma_buf->resv_obj); fs_reclaim_acquire(GFP_KERNEL); fs_reclaim_release(GFP_KERNEL); ww_mutex_unlock(dma_buf->resv_obj); }

in dma_buf_init(). We're using the fs_reclaim_acquire/release check very successfully to improve our igt test coverage for i915.ko in other areas.

Totally unrelated to dev->struct_mutex, but thoughts? Well for dev->struct_mutex we could at least decide on one true way to nest resv_obj vs. dev->struct_mutex as maybe an interim step, but not sure how much that would help. -Daniel

Christian.

...

-Daniel

...

...

---

drivers/dma-buf/dma-buf.c | 9 ++++++--- include/linux/dma-buf.h | 4 ++++ 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index dc94e76e2e2a..49f23b791eb8 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -665,7 +665,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL);

• sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);

• reservation_object_lock(attach->dmabuf->resv, NULL);
• sg_table = dma_buf_map_attachment_locked(attach, direction);
• reservation_object_unlock(attach->dmabuf->resv); if (!sg_table) sg_table = ERR_PTR(-ENOMEM);

@@ -715,8 +717,9 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return;

• attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

• 				direction);
  

• reservation_object_lock(attach->dmabuf->resv, NULL);
• dma_buf_unmap_attachment_locked(attach, sg_table, direction);
• reservation_object_unlock(attach->dmabuf->resv); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index a25e754ae2f7..024658d1f22e 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -118,6 +118,8 @@ struct dma_buf_ops { * any other kind of sharing that the exporter might wish to make * available to buffer-users. *

• * This is called with the dmabuf->resv object locked.
  

• *
  

  • Returns:
  • A &sg_table scatter list of or the backing storage of the DMA buffer,

@@ -138,6 +140,8 @@ struct dma_buf_ops { * It should also unpin the backing storage if this is the last mapping * of the DMA buffer, it the exporter supports backing storage * migration.

• *
  

• * This is called with the dmabuf->resv object locked.
  

  */ void (*unmap_dma_buf)(struct dma_buf_attachment *, struct sg_table *,

-- 2.14.1

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

On 06/22/2018 10:11 PM, Christian König wrote:

First step towards unpinned DMA buf operation.

I've checked the DRM drivers to potential locking of the reservation object, but essentially we need to audit all implementations of the dma_buf _ops for this to work.

v2: reordered

Signed-off-by: Christian König christian.koenig@amd.com

looks good for me.

Reviewed-by: Junwei Zhang Jerry.Zhang@amd.com

Jerry

---

drivers/dma-buf/dma-buf.c | 9 ++++++--- include/linux/dma-buf.h | 4 ++++ 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index dc94e76e2e2a..49f23b791eb8 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -665,7 +665,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL);

• sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);

• reservation_object_lock(attach->dmabuf->resv, NULL);
• sg_table = dma_buf_map_attachment_locked(attach, direction);
• reservation_object_unlock(attach->dmabuf->resv); if (!sg_table) sg_table = ERR_PTR(-ENOMEM);

@@ -715,8 +717,9 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return;

• attach->dmabuf->ops->unmap_dma_buf(attach, sg_table,

• 				direction);
  

• reservation_object_lock(attach->dmabuf->resv, NULL);
• dma_buf_unmap_attachment_locked(attach, sg_table, direction);
• reservation_object_unlock(attach->dmabuf->resv); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index a25e754ae2f7..024658d1f22e 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -118,6 +118,8 @@ struct dma_buf_ops { * any other kind of sharing that the exporter might wish to make * available to buffer-users. *

• * This is called with the dmabuf->resv object locked.
  

• *
  

  • Returns:
  • A &sg_table scatter list of or the backing storage of the DMA buffer,

@@ -138,6 +140,8 @@ struct dma_buf_ops { * It should also unpin the backing storage if this is the last mapping * of the DMA buffer, it the exporter supports backing storage * migration.

• *
  

• * This is called with the dmabuf->resv object locked.
  

  */ void (*unmap_dma_buf)(struct dma_buf_attachment *, struct sg_table *,

On 06/22/2018 10:11 PM, Christian König wrote:

The caching of SGT's done by the DRM code is actually quite harmful and should probably removed altogether in the long term.

Start by providing a separate DMA-buf export implementation in amdgpu. This is also a prerequisite of unpinned DMA-buf handling.

v2: fix unintended recursion, remove debugging leftovers v3: split out from unpinned DMA-buf work

Signed-off-by: Christian König christian.koenig@amd.com

drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 - drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 1 - drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c | 94 +++++++++++++------------------ 3 files changed, 39 insertions(+), 57 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index d8e0cc08f9db..5e71af8dd3a7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -373,7 +373,6 @@ int amdgpu_gem_object_open(struct drm_gem_object *obj, void amdgpu_gem_object_close(struct drm_gem_object *obj, struct drm_file *file_priv); unsigned long amdgpu_gem_timeout(uint64_t timeout_ns); -struct sg_table *amdgpu_gem_prime_get_sg_table(struct drm_gem_object *obj); struct drm_gem_object * amdgpu_gem_prime_import_sg_table(struct drm_device *dev, struct dma_buf_attachment *attach, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index a549483032b0..cdf0be85d361 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -919,7 +919,6 @@ static struct drm_driver kms_driver = { .gem_prime_export = amdgpu_gem_prime_export, .gem_prime_import = amdgpu_gem_prime_import, .gem_prime_res_obj = amdgpu_gem_prime_res_obj,

• .gem_prime_get_sg_table = amdgpu_gem_prime_get_sg_table,

I may miss some patches or important info.

Even applied the series of patch, I still could find below code in drm_gem_map_dma_buf(). In this case, it will cause NULL pointer access. Please help me out of here. {{{ sgt = obj->dev->driver->gem_prime_get_sg_table(obj); }}}

Jerry

.gem_prime_import_sg_table = amdgpu_gem_prime_import_sg_table, .gem_prime_vmap = amdgpu_gem_prime_vmap, .gem_prime_vunmap = amdgpu_gem_prime_vunmap, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c index b2286bc41aec..038a8c8488b7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_prime.c @@ -40,22 +40,6 @@

static const struct dma_buf_ops amdgpu_dmabuf_ops;

-/**

• • amdgpu_gem_prime_get_sg_table - &drm_driver.gem_prime_get_sg_table
• • implementation
• • @obj: GEM buffer object
• • Returns:
• • A scatter/gather table for the pinned pages of the buffer object's memory.
• */

-struct sg_table *amdgpu_gem_prime_get_sg_table(struct drm_gem_object *obj) -{

• struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj);
• int npages = bo->tbo.num_pages;
• return drm_prime_pages_to_sg(bo->tbo.ttm->pages, npages);

-}

• /**
  • amdgpu_gem_prime_vmap - &dma_buf_ops.vmap implementation
  • @obj: GEM buffer object

@@ -189,35 +173,29 @@ amdgpu_gem_prime_import_sg_table(struct drm_device *dev, }

/**

• • amdgpu_gem_map_attach - &dma_buf_ops.attach implementation
• • @dma_buf: shared DMA buffer
• • @target_dev: target device

• • amdgpu_gem_map_dma_buf - &dma_buf_ops.map_dma_buf implementation
  • @attach: DMA-buf attachment
• • @dir: DMA direction
  • Makes sure that the shared DMA buffer can be accessed by the target device.
  • For now, simply pins it to the GTT domain, where it should be accessible by
  • all DMA devices.
  • Returns:

• • 0 on success or negative error code.

• • sg_table filled with the DMA addresses to use or ERR_PRT with negative error
• • code.
  */

-static int amdgpu_gem_map_attach(struct dma_buf *dma_buf,

• 		 struct dma_buf_attachment *attach)
  

+static struct sg_table * +amdgpu_gem_map_dma_buf(struct dma_buf_attachment *attach,

•        enum dma_data_direction dir)
  

  {
• struct dma_buf *dma_buf = attach->dmabuf; struct drm_gem_object *obj = dma_buf->priv; struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
• struct sg_table *sgt; long r;

• r = drm_gem_map_attach(dma_buf, attach);
• if (r)

• return r;
  

• r = amdgpu_bo_reserve(bo, false);
• if (unlikely(r != 0))

• goto error_detach;
  

• if (attach->dev->driver != adev->dev->driver) { /*
  • Wait for all shared fences to complete before we switch to future

@@ -228,54 +206,62 @@ static int amdgpu_gem_map_attach(struct dma_buf *dma_buf, MAX_SCHEDULE_TIMEOUT); if (unlikely(r < 0)) { DRM_DEBUG_PRIME("Fence wait failed: %li\n", r);

• 	goto error_unreserve;
  

• 	return ERR_PTR(r);
  

  } }

  /* pin buffer into GTT */ r = amdgpu_bo_pin(bo, AMDGPU_GEM_DOMAIN_GTT, NULL); if (r)

• goto error_unreserve;
  

• return ERR_PTR(r);
  

• sgt = drm_prime_pages_to_sg(bo->tbo.ttm->pages, bo->tbo.num_pages);

• if (IS_ERR(sgt))

• return sgt;
  

• if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,

• 	      DMA_ATTR_SKIP_CPU_SYNC))
  

• goto error_free;
  
  

  if (attach->dev->driver != adev->dev->driver) bo->prime_shared_count++;

-error_unreserve:

• amdgpu_bo_unreserve(bo);

• return sgt;

-error_detach:

• if (r)

• drm_gem_map_detach(dma_buf, attach);
  

• return r;

+error_free:

• sg_free_table(sgt);

• kfree(sgt);

• return ERR_PTR(-ENOMEM); }

  /**

• • amdgpu_gem_map_detach - &dma_buf_ops.detach implementation
• • @dma_buf: shared DMA buffer

• • amdgpu_gem_unmap_dma_buf - &dma_buf_ops.unmap_dma_buf implementation
  • @attach: DMA-buf attachment
• • @sgt: sg_table to unmap
• • @dir: DMA direction
  • This is called when a shared DMA buffer no longer needs to be accessible by
  • the other device. For now, simply unpins the buffer from GTT.
  */

-static void amdgpu_gem_map_detach(struct dma_buf *dma_buf,

• 		  struct dma_buf_attachment *attach)
  

+static void amdgpu_gem_unmap_dma_buf(struct dma_buf_attachment *attach,

• 		     struct sg_table *sgt,
  

• 		     enum dma_data_direction dir)
  

  {
• struct dma_buf *dma_buf = attach->dmabuf; struct drm_gem_object *obj = dma_buf->priv; struct amdgpu_bo *bo = gem_to_amdgpu_bo(obj); struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);

• int ret = 0;

• ret = amdgpu_bo_reserve(bo, true);

• if (unlikely(ret != 0))

• goto error;
  
  

  amdgpu_bo_unpin(bo);

• if (attach->dev->driver != adev->dev->driver && bo->prime_shared_count) bo->prime_shared_count--;

• amdgpu_bo_unreserve(bo);

-error:

• drm_gem_map_detach(dma_buf, attach);

• if (sgt) {

• dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
  

• sg_free_table(sgt);
  

• kfree(sgt);
  

• } }

  /**

@@ -333,10 +319,8 @@ static int amdgpu_gem_begin_cpu_access(struct dma_buf *dma_buf, }

static const struct dma_buf_ops amdgpu_dmabuf_ops = {

• .attach = amdgpu_gem_map_attach,
• .detach = amdgpu_gem_map_detach,
• .map_dma_buf = drm_gem_map_dma_buf,
• .unmap_dma_buf = drm_gem_unmap_dma_buf,

• .map_dma_buf = amdgpu_gem_map_dma_buf,
• .unmap_dma_buf = amdgpu_gem_unmap_dma_buf, .release = drm_gem_dmabuf_release, .begin_cpu_access = amdgpu_gem_begin_cpu_access, .map = drm_gem_dmabuf_kmap,