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 <jens.axboe@oracle.com>
diff --git a/include/asm-frv/scatterlist.h b/include/asm-frv/scatterlist.h
index 8e827fa..53dade7 100644
--- a/include/asm-frv/scatterlist.h
+++ b/include/asm-frv/scatterlist.h
@@ -22,7 +22,7 @@
* and that's it. There's no excuse for not highmem enabling YOUR driver. /jens
*/
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;