blob: 272104b369b8c033093da666bd56185a749e1de3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
|
#ifndef _I386_SCATTERLIST_H
#define _I386_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 {
char * address; /* Location data is to be transferred to, NULL for
* highmem page */
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 (0x00ffffff)
#endif /* !(_I386_SCATTERLIST_H) */
|
