1/* 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>
12#include <linux/module.h>
13
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
22EXPORT_SYMBOL(kmap);
23
24void kunmap(struct page *page)
25{
26	if (in_interrupt())
27		BUG();
28	if (!PageHighMem(page))
29		return;
30	kunmap_high(page);
31}
32
33EXPORT_SYMBOL(kunmap);
34
35void *kmap_atomic(struct page *page)
36{
37	unsigned long paddr;
38	int type;
39
40	preempt_disable();
41	pagefault_disable();
42	type = kmap_atomic_idx_push();
43	paddr = page_to_phys(page);
44
45	switch (type) {
46	/*
47	 * The first 4 primary maps are reserved for architecture code
48	 */
49	case 0:		return __kmap_atomic_primary(0, paddr, 6);
50	case 1:		return __kmap_atomic_primary(0, paddr, 7);
51	case 2:		return __kmap_atomic_primary(0, paddr, 8);
52	case 3:		return __kmap_atomic_primary(0, paddr, 9);
53	case 4:		return __kmap_atomic_primary(0, paddr, 10);
54
55	case 5 ... 5 + NR_TLB_LINES - 1:
56		return __kmap_atomic_secondary(type - 5, paddr);
57
58	default:
59		BUG();
60		return NULL;
61	}
62}
63EXPORT_SYMBOL(kmap_atomic);
64
65void __kunmap_atomic(void *kvaddr)
66{
67	int type = kmap_atomic_idx();
68	switch (type) {
69	case 0:		__kunmap_atomic_primary(0, 6);	break;
70	case 1:		__kunmap_atomic_primary(0, 7);	break;
71	case 2:		__kunmap_atomic_primary(0, 8);	break;
72	case 3:		__kunmap_atomic_primary(0, 9);	break;
73	case 4:		__kunmap_atomic_primary(0, 10);	break;
74
75	case 5 ... 5 + NR_TLB_LINES - 1:
76		__kunmap_atomic_secondary(type - 5, kvaddr);
77		break;
78
79	default:
80		BUG();
81	}
82	kmap_atomic_idx_pop();
83	pagefault_enable();
84	preempt_enable();
85}
86EXPORT_SYMBOL(__kunmap_atomic);
87