Commit fc8d5bba authored by Herbert Xu's avatar Herbert Xu
Browse files

lib/scatterlist: Add SG_MITER_LOCAL and use it 



Add kmap_local support to the scatterlist iterator.  Use it for
all the helper functions in lib/scatterlist.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent f3bda3b9

include/linux/scatterlist.h

+1 −0
Original line number Diff line number Diff line
@@ -671,6 +671,7 @@ sg_page_iter_dma_address(struct sg_dma_page_iter *dma_iter) 
#define SG_MITER_ATOMIC		(1 << 0)	 /* use kmap_atomic */

#define SG_MITER_TO_SG		(1 << 1)	/* flush back to phys on unmap */

#define SG_MITER_FROM_SG	(1 << 2)	/* nop */

#define SG_MITER_LOCAL		(1 << 3)	 /* use kmap_local */



struct sg_mapping_iter {

	/* the following three fields can be accessed directly */

lib/scatterlist.c

+8 −4
Original line number Diff line number Diff line
@@ -879,7 +879,7 @@ EXPORT_SYMBOL(sg_miter_skip); 
 *   @miter->addr and @miter->length point to the current mapping.

 *

 * Context:

 *   May sleep if !SG_MITER_ATOMIC.

 *   May sleep if !SG_MITER_ATOMIC && !SG_MITER_LOCAL.

 *

 * Returns:

 *   true if @miter contains the next mapping.  false if end of sg
@@ -901,6 +901,8 @@ bool sg_miter_next(struct sg_mapping_iter *miter) 


	if (miter->__flags & SG_MITER_ATOMIC)

		miter->addr = kmap_atomic(miter->page) + miter->__offset;

	else if (miter->__flags & SG_MITER_LOCAL)

		miter->addr = kmap_local_page(miter->page) + miter->__offset;

	else

		miter->addr = kmap(miter->page) + miter->__offset;
@@ -936,7 +938,9 @@ void sg_miter_stop(struct sg_mapping_iter *miter) 
		if (miter->__flags & SG_MITER_ATOMIC) {

			WARN_ON_ONCE(!pagefault_disabled());

			kunmap_atomic(miter->addr);

		} else

		} else if (miter->__flags & SG_MITER_LOCAL)

			kunmap_local(miter->addr);

		else

			kunmap(miter->page);



		miter->page = NULL;
@@ -965,7 +969,7 @@ size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, 
{

	unsigned int offset = 0;

	struct sg_mapping_iter miter;

	unsigned int sg_flags = SG_MITER_ATOMIC;

	unsigned int sg_flags = SG_MITER_LOCAL;



	if (to_buffer)

		sg_flags |= SG_MITER_FROM_SG;
@@ -1080,7 +1084,7 @@ size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents, 
{

	unsigned int offset = 0;

	struct sg_mapping_iter miter;

	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;

	unsigned int sg_flags = SG_MITER_LOCAL | SG_MITER_TO_SG;



	sg_miter_start(&miter, sgl, nents, sg_flags);