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