kernel-fxtec-pro1x/include/asm-parisc/scatterlist.h
Jens Axboe 18dabf473e 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>
2007-10-22 21:20:01 +02:00

24 lines
598 B
C

#ifndef _ASM_PARISC_SCATTERLIST_H
#define _ASM_PARISC_SCATTERLIST_H
#include <asm/page.h>
#include <asm/types.h>
struct scatterlist {
unsigned long page_link;
unsigned int offset;
unsigned int length;
/* an IOVA can be 64-bits on some PA-Risc platforms. */
dma_addr_t iova; /* I/O Virtual Address */
__u32 iova_length; /* bytes mapped */
};
#define sg_virt_addr(sg) ((unsigned long)(page_address(sg->page) + sg->offset))
#define sg_dma_address(sg) ((sg)->iova)
#define sg_dma_len(sg) ((sg)->iova_length)
#define ISA_DMA_THRESHOLD (~0UL)
#endif /* _ASM_PARISC_SCATTERLIST_H */