diff options
| author | Jason Gunthorpe <jgg@mellanox.com> | 2019-01-04 11:40:21 -0700 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-02-11 15:02:33 -0700 |
| commit | d901b2760dc6cd5fbbf2eac31d71d94baa6c4aef (patch) | |
| tree | 6598a5b011cea1bcdf160c2be9fd4e677d387e2b /drivers/gpu/drm/vmwgfx | |
| parent | f368ff188ae4b3ef6f740a15999ea0373261b619 (diff) | |
lib/scatterlist: Provide a DMA page iterator
Commit 2db76d7c3c6d ("lib/scatterlist: sg_page_iter: support sg lists w/o
backing pages") introduced the sg_page_iter_dma_address() function without
providing a way to use it in the general case. If the sg_dma_len() is not
equal to the sg length callers cannot safely use the
for_each_sg_page/sg_page_iter_dma_address combination.
Resolve this API mistake by providing a DMA specific iterator,
for_each_sg_dma_page(), that uses the right length so
sg_page_iter_dma_address() works as expected with all sglists.
A new iterator type is introduced to provide compile-time safety against
wrongly mixing accessors and iterators.
Acked-by: Christoph Hellwig <hch@lst.de> (for scatterlist)
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> (ipu3-cio2)
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/gpu/drm/vmwgfx')
| -rw-r--r-- | drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c index 31786b200afc..a3357ff7540d 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c @@ -311,7 +311,13 @@ static dma_addr_t __vmw_piter_dma_addr(struct vmw_piter *viter) static dma_addr_t __vmw_piter_sg_addr(struct vmw_piter *viter) { - return sg_page_iter_dma_address(&viter->iter); + /* + * FIXME: This driver wrongly mixes DMA and CPU SG list iteration and + * needs revision. See + * https://lore.kernel.org/lkml/20190104223531.GA1705@ziepe.ca/ + */ + return sg_page_iter_dma_address( + container_of(&viter->iter, struct sg_dma_page_iter, base)); } |