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
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
/*
* arch/arm/mm/highmem.c -- ARM highmem support
*
* Author: Nicolas Pitre
* Created: september 8, 2008
* Copyright: Marvell Semiconductors Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <asm/fixmap.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include "mm.h"
void *kmap(struct page *page)
{
might_sleep();
if (!PageHighMem(page))
return page_address(page);
return kmap_high(page);
}
EXPORT_SYMBOL(kmap);
void kunmap(struct page *page)
{
BUG_ON(in_interrupt());
if (!PageHighMem(page))
return;
kunmap_high(page);
}
EXPORT_SYMBOL(kunmap);
void *kmap_atomic(struct page *page, enum km_type type)
{
unsigned int idx;
unsigned long vaddr;
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
/*
* With debugging enabled, kunmap_atomic forces that entry to 0.
* Make sure it was indeed properly unmapped.
*/
BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
#endif
set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0);
/*
* When debugging is off, kunmap_atomic leaves the previous mapping
* in place, so this TLB flush ensures the TLB is updated with the
* new mapping.
*/
local_flush_tlb_kernel_page(vaddr);
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic);
void kunmap_atomic(void *kvaddr, enum km_type type)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
unsigned int idx = type + KM_TYPE_NR * smp_processor_id();
if (kvaddr >= (void *)FIXADDR_START) {
__cpuc_flush_dcache_page((void *)vaddr);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
set_pte_ext(TOP_PTE(vaddr), __pte(0), 0);
local_flush_tlb_kernel_page(vaddr);
#else
(void) idx; /* to kill a warning */
#endif
}
pagefault_enable();
}
EXPORT_SYMBOL(kunmap_atomic);
void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
{
unsigned int idx;
unsigned long vaddr;
pagefault_disable();
idx = type + KM_TYPE_NR * smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
#endif
set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0);
local_flush_tlb_kernel_page(vaddr);
return (void *)vaddr;
}
struct page *kmap_atomic_to_page(const void *ptr)
{
unsigned long vaddr = (unsigned long)ptr;
pte_t *pte;
if (vaddr < FIXADDR_START)
return virt_to_page(ptr);
pte = TOP_PTE(vaddr);
return pte_page(*pte);
}
|
