From 18dabf473e15850c0dbc8ff13ac1e2806d542c15 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 22 Oct 2007 19:57:20 +0200 Subject: Change table chaining layout Change the page member of the scatterlist structure to be an unsigned long, and encode more stuff in the lower bits: - Bits 0 and 1 zero: this is a normal sg entry. Next sg entry is located at sg + 1. - Bit 0 set: this is a chain entry, the next real entry is at ->page_link with the two low bits masked off. - Bit 1 set: this is the final entry in the sg entry. sg_next() will return NULL when passed such an entry. It's thus important that sg table users use the proper accessors to get and set the page member. Signed-off-by: Jens Axboe --- include/asm-sh/scatterlist.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/asm-sh') diff --git a/include/asm-sh/scatterlist.h b/include/asm-sh/scatterlist.h index b9ae53c38365..bc7c809e16fb 100644 --- a/include/asm-sh/scatterlist.h +++ b/include/asm-sh/scatterlist.h @@ -4,7 +4,7 @@ #include struct scatterlist { - struct page * page; /* Location for highmem page, if any */ + unsigned long page_link; unsigned int offset;/* for highmem, page offset */ dma_addr_t dma_address; unsigned int length; -- cgit v1.2.3-59-g8ed1b