1#include <linux/compiler.h>
2#include <linux/module.h>
3#include <linux/highmem.h>
4#include <linux/sched.h>
5#include <linux/smp.h>
6#include <asm/fixmap.h>
7#include <asm/tlbflush.h>
8
9static pte_t *kmap_pte;
10
11unsigned long highstart_pfn, highend_pfn;
12
13void *kmap(struct page *page)
14{
15 void *addr;
16
17 might_sleep();
18 if (!PageHighMem(page))
19 return page_address(page);
20 addr = kmap_high(page);
21 flush_tlb_one((unsigned long)addr);
22
23 return addr;
24}
25EXPORT_SYMBOL(kmap);
26
27void kunmap(struct page *page)
28{
29 BUG_ON(in_interrupt());
30 if (!PageHighMem(page))
31 return;
32 kunmap_high(page);
33}
34EXPORT_SYMBOL(kunmap);
35
36
37
38
39
40
41
42
43
44
45void *kmap_atomic(struct page *page)
46{
47 unsigned long vaddr;
48 int idx, type;
49
50 preempt_disable();
51 pagefault_disable();
52 if (!PageHighMem(page))
53 return page_address(page);
54
55 type = kmap_atomic_idx_push();
56 idx = type + KM_TYPE_NR*smp_processor_id();
57 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
58#ifdef CONFIG_DEBUG_HIGHMEM
59 BUG_ON(!pte_none(*(kmap_pte - idx)));
60#endif
61 set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
62 local_flush_tlb_one((unsigned long)vaddr);
63
64 return (void*) vaddr;
65}
66EXPORT_SYMBOL(kmap_atomic);
67
68void __kunmap_atomic(void *kvaddr)
69{
70 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
71 int type __maybe_unused;
72
73 if (vaddr < FIXADDR_START) {
74 pagefault_enable();
75 preempt_enable();
76 return;
77 }
78
79 type = kmap_atomic_idx();
80#ifdef CONFIG_DEBUG_HIGHMEM
81 {
82 int idx = type + KM_TYPE_NR * smp_processor_id();
83
84 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
85
86
87
88
89
90 pte_clear(&init_mm, vaddr, kmap_pte-idx);
91 local_flush_tlb_one(vaddr);
92 }
93#endif
94 kmap_atomic_idx_pop();
95 pagefault_enable();
96 preempt_enable();
97}
98EXPORT_SYMBOL(__kunmap_atomic);
99
100
101
102
103
104void *kmap_atomic_pfn(unsigned long pfn)
105{
106 unsigned long vaddr;
107 int idx, type;
108
109 preempt_disable();
110 pagefault_disable();
111
112 type = kmap_atomic_idx_push();
113 idx = type + KM_TYPE_NR*smp_processor_id();
114 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
115 set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
116 flush_tlb_one(vaddr);
117
118 return (void*) vaddr;
119}
120
121struct page *kmap_atomic_to_page(void *ptr)
122{
123 unsigned long idx, vaddr = (unsigned long)ptr;
124 pte_t *pte;
125
126 if (vaddr < FIXADDR_START)
127 return virt_to_page(ptr);
128
129 idx = virt_to_fix(vaddr);
130 pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
131 return pte_page(*pte);
132}
133
134void __init kmap_init(void)
135{
136 unsigned long kmap_vstart;
137
138
139 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
140 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
141}
142