33 lines
942 B
C
33 lines
942 B
C
#ifndef _ASM_SCATTERLIST_H
|
|
#define _ASM_SCATTERLIST_H
|
|
|
|
/*
|
|
* Drivers must set either ->address or (preferred) ->page and ->offset
|
|
* to indicate where data must be transferred to/from.
|
|
*
|
|
* Using ->page is recommended since it handles highmem data as well as
|
|
* low mem. ->address is restricted to data which has a virtual mapping, and
|
|
* it will go away in the future. Updating to ->page can be automated very
|
|
* easily -- something like
|
|
*
|
|
* sg->address = some_ptr;
|
|
*
|
|
* can be rewritten as
|
|
*
|
|
* sg->page = virt_to_page(some_ptr);
|
|
* sg->offset = (unsigned long) some_ptr & ~PAGE_MASK;
|
|
*
|
|
* 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 int offset; /* for highmem, page offset */
|
|
|
|
dma_addr_t dma_address;
|
|
unsigned int length;
|
|
};
|
|
|
|
#define ISA_DMA_THRESHOLD (0xffffffffUL)
|
|
|
|
#endif /* !_ASM_SCATTERLIST_H */
|