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>
diff --git a/.clang-format b/.clang-format
index bc2ffb2..335ce29 100644
--- a/.clang-format
+++ b/.clang-format
@@ -240,6 +240,7 @@
- 'for_each_set_bit'
- 'for_each_set_bit_from'
- 'for_each_sg'
+ - 'for_each_sg_dma_page'
- 'for_each_sg_page'
- 'for_each_sibling_event'
- '__for_each_thread'