Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/frv/mm/highmem.c
10817 views
1
/* highmem.c: arch-specific highmem stuff

2
 *

3
 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.

4
 * Written by David Howells ([email protected])

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


14
void *kmap(struct page *page)

15
{

16
	might_sleep();

17
	if (!PageHighMem(page))

18
		return page_address(page);

19
	return kmap_high(page);

20
}

21


22
EXPORT_SYMBOL(kmap);

23


24
void kunmap(struct page *page)

25
{

26
	if (in_interrupt())

27
		BUG();

28
	if (!PageHighMem(page))

29
		return;

30
	kunmap_high(page);

31
}

32


33
EXPORT_SYMBOL(kunmap);

34


35
struct page *kmap_atomic_to_page(void *ptr)

36
{

37
	return virt_to_page(ptr);

38
}

39


40
void *__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
}

67
EXPORT_SYMBOL(__kmap_atomic);

68


69
void __kunmap_atomic(void *kvaddr)

70
{

71
	int type = kmap_atomic_idx();

72
	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
	}

86
	kmap_atomic_idx_pop();

87
	pagefault_enable();

88
}

89
EXPORT_SYMBOL(__kunmap_atomic);

90


91