blob: fd7fcd4c2e3399d844f50fed780093880639cb10 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* highmem.c: arch-specific highmem stuff
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11#include <linux/highmem.h>
David Howells40234402006-01-08 01:01:19 -080012#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
14void *kmap(struct page *page)
15{
16 might_sleep();
17 if (!PageHighMem(page))
18 return page_address(page);
19 return kmap_high(page);
20}
21
David Howells40234402006-01-08 01:01:19 -080022EXPORT_SYMBOL(kmap);
23
Linus Torvalds1da177e2005-04-16 15:20:36 -070024void kunmap(struct page *page)
25{
26 if (in_interrupt())
27 BUG();
28 if (!PageHighMem(page))
29 return;
30 kunmap_high(page);
31}
32
David Howells40234402006-01-08 01:01:19 -080033EXPORT_SYMBOL(kunmap);
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035struct page *kmap_atomic_to_page(void *ptr)
36{
37 return virt_to_page(ptr);
38}
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070039
40void *__kmap_atomic(struct page *page)
41{
42 unsigned long paddr;
43 int type;
44
45 pagefault_disable();
46 type = kmap_atomic_idx_push();
47 paddr = page_to_phys(page);
48
49 switch (type) {
50 /*
51 * The first 4 primary maps are reserved for architecture code
52 */
53 case 0: return __kmap_atomic_primary(4, paddr, 6);
54 case 1: return __kmap_atomic_primary(5, paddr, 7);
55 case 2: return __kmap_atomic_primary(6, paddr, 8);
56 case 3: return __kmap_atomic_primary(7, paddr, 9);
57 case 4: return __kmap_atomic_primary(8, paddr, 10);
58
59 case 5 ... 5 + NR_TLB_LINES - 1:
60 return __kmap_atomic_secondary(type - 5, paddr);
61
62 default:
63 BUG();
64 return NULL;
65 }
66}
67EXPORT_SYMBOL(__kmap_atomic);
68
69void __kunmap_atomic(void *kvaddr)
70{
Peter Zijlstra20273942010-10-27 15:32:58 -070071 int type = kmap_atomic_idx();
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070072 switch (type) {
73 case 0: __kunmap_atomic_primary(4, 6); break;
74 case 1: __kunmap_atomic_primary(5, 7); break;
75 case 2: __kunmap_atomic_primary(6, 8); break;
76 case 3: __kunmap_atomic_primary(7, 9); break;
77 case 4: __kunmap_atomic_primary(8, 10); break;
78
79 case 5 ... 5 + NR_TLB_LINES - 1:
80 __kunmap_atomic_secondary(type - 5, kvaddr);
81 break;
82
83 default:
84 BUG();
85 }
Peter Zijlstra20273942010-10-27 15:32:58 -070086 kmap_atomic_idx_pop();
Peter Zijlstra3e4d3af2010-10-26 14:21:51 -070087 pagefault_enable();
88}
89EXPORT_SYMBOL(__kunmap_atomic);