Commit e9ed7aff authored by Herbert Xu's avatar Herbert Xu
Browse files

crypto: scatterwalk - Use nth_page instead of doing it by hand 



Curiously, the Crypto API scatterwalk incremented pages by hand
rather than using nth_page.  Possibly because scatterwalk predates
nth_page (the following commit is from the history tree):

	commit 3957f2b34960d85b63e814262a8be7d5ad91444d
	Author: James Morris <jmorris@intercode.com.au>
	Date:   Sun Feb 2 07:35:32 2003 -0800

	    [CRYPTO]: in/out scatterlist support for ciphers.

Fix this by using nth_page.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 795e5bdb

include/crypto/scatterwalk.h

+20 −10
Original line number Diff line number Diff line
@@ -100,11 +100,15 @@ static inline void scatterwalk_get_sglist(struct scatter_walk *walk, 
static inline void scatterwalk_map(struct scatter_walk *walk)

{

	struct page *base_page = sg_page(walk->sg);

	unsigned int offset = walk->offset;

	void *addr;



	if (IS_ENABLED(CONFIG_HIGHMEM)) {

		walk->__addr = kmap_local_page(base_page +

					       (walk->offset >> PAGE_SHIFT)) +

			       offset_in_page(walk->offset);

		struct page *page;



		page = nth_page(base_page, offset >> PAGE_SHIFT);

		offset = offset_in_page(offset);

		addr = kmap_local_page(page) + offset;

	} else {

		/*

		 * When !HIGHMEM we allow the walker to return segments that
@@ -117,8 +121,10 @@ static inline void scatterwalk_map(struct scatter_walk *walk) 
		 * in the direct map, but this makes it clearer what is really

		 * going on.

		 */

		walk->__addr = page_address(base_page) + walk->offset;

		addr = page_address(base_page) + offset;

	}



	walk->__addr = addr;

}



/**
@@ -189,14 +195,18 @@ static inline void scatterwalk_done_dst(struct scatter_walk *walk, 
	 * reliably optimized out or not.

	 */

	if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) {

		struct page *base_page, *start_page, *end_page, *page;

		struct page *base_page;

		unsigned int offset;

		int start, end, i;



		base_page = sg_page(walk->sg);

		start_page = base_page + (walk->offset >> PAGE_SHIFT);

		end_page = base_page + ((walk->offset + nbytes +

					 PAGE_SIZE - 1) >> PAGE_SHIFT);

		for (page = start_page; page < end_page; page++)

			flush_dcache_page(page);

		offset = walk->offset;

		start = offset >> PAGE_SHIFT;

		end = start + (nbytes >> PAGE_SHIFT);

		end += (offset_in_page(offset) + offset_in_page(nbytes) +

			PAGE_SIZE - 1) >> PAGE_SHIFT;

		for (i = start; i < end; i++)

			flush_dcache_page(nth_page(base_page, i));

	}

	scatterwalk_advance(walk, nbytes);

}