scatterlist: allow limited chaining without ARCH_HAS_SG_CHAIN
There are a couple of uses of struct scatterlist that never go to
the dma_map_sg() helper and thus don't care about ARCH_HAS_SG_CHAIN
which indicates that we can map chained S/G list.
The most important one is the crypto code, which currently has
to open code a few helpers to always allow chaining. This patch
removes a few #ifdef ARCH_HAS_SG_CHAIN statements so that we can
switch the crypto code to these common helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 9b1ef0c..698e906 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -161,10 +161,6 @@
static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents,
struct scatterlist *sgl)
{
-#ifndef CONFIG_ARCH_HAS_SG_CHAIN
- BUG();
-#endif
-
/*
* offset and length are unused for chain entry. Clear them.
*/
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index d105a9f..bafa993 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -105,16 +105,12 @@
**/
struct scatterlist *sg_last(struct scatterlist *sgl, unsigned int nents)
{
-#ifndef CONFIG_ARCH_HAS_SG_CHAIN
- struct scatterlist *ret = &sgl[nents - 1];
-#else
struct scatterlist *sg, *ret = NULL;
unsigned int i;
for_each_sg(sgl, sg, nents, i)
ret = sg;
-#endif
#ifdef CONFIG_DEBUG_SG
BUG_ON(sgl[0].sg_magic != SG_MAGIC);
BUG_ON(!sg_is_last(ret));