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1#include <linux/compiler.h>
2#include <linux/init.h>
3#include <linux/export.h>
4#include <linux/highmem.h>
5#include <linux/sched.h>
6#include <linux/smp.h>
7#include <asm/fixmap.h>
8#include <asm/tlbflush.h>
9
10static pte_t *kmap_pte;
11
12unsigned long highstart_pfn, highend_pfn;
13
14void *kmap(struct page *page)
15{
16 void *addr;
17
18 might_sleep();
19 if (!PageHighMem(page))
20 return page_address(page);
21 addr = kmap_high(page);
22 flush_tlb_one((unsigned long)addr);
23
24 return addr;
25}
26EXPORT_SYMBOL(kmap);
27
28void kunmap(struct page *page)
29{
30 BUG_ON(in_interrupt());
31 if (!PageHighMem(page))
32 return;
33 kunmap_high(page);
34}
35EXPORT_SYMBOL(kunmap);
36
37/*
38 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
39 * no global lock is needed and because the kmap code must perform a global TLB
40 * invalidation when the kmap pool wraps.
41 *
42 * However when holding an atomic kmap is is not legal to sleep, so atomic
43 * kmaps are appropriate for short, tight code paths only.
44 */
45
46void *kmap_atomic(struct page *page)
47{
48 unsigned long vaddr;
49 int idx, type;
50
51 preempt_disable();
52 pagefault_disable();
53 if (!PageHighMem(page))
54 return page_address(page);
55
56 type = kmap_atomic_idx_push();
57 idx = type + KM_TYPE_NR*smp_processor_id();
58 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
59#ifdef CONFIG_DEBUG_HIGHMEM
60 BUG_ON(!pte_none(*(kmap_pte - idx)));
61#endif
62 set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
63 local_flush_tlb_one((unsigned long)vaddr);
64
65 return (void*) vaddr;
66}
67EXPORT_SYMBOL(kmap_atomic);
68
69void __kunmap_atomic(void *kvaddr)
70{
71 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
72 int type __maybe_unused;
73
74 if (vaddr < FIXADDR_START) { // FIXME
75 pagefault_enable();
76 preempt_enable();
77 return;
78 }
79
80 type = kmap_atomic_idx();
81#ifdef CONFIG_DEBUG_HIGHMEM
82 {
83 int idx = type + KM_TYPE_NR * smp_processor_id();
84
85 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
86
87 /*
88 * force other mappings to Oops if they'll try to access
89 * this pte without first remap it
90 */
91 pte_clear(&init_mm, vaddr, kmap_pte-idx);
92 local_flush_tlb_one(vaddr);
93 }
94#endif
95 kmap_atomic_idx_pop();
96 pagefault_enable();
97 preempt_enable();
98}
99EXPORT_SYMBOL(__kunmap_atomic);
100
101/*
102 * This is the same as kmap_atomic() but can map memory that doesn't
103 * have a struct page associated with it.
104 */
105void *kmap_atomic_pfn(unsigned long pfn)
106{
107 unsigned long vaddr;
108 int idx, type;
109
110 preempt_disable();
111 pagefault_disable();
112
113 type = kmap_atomic_idx_push();
114 idx = type + KM_TYPE_NR*smp_processor_id();
115 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
116 set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
117 flush_tlb_one(vaddr);
118
119 return (void*) vaddr;
120}
121
122void __init kmap_init(void)
123{
124 unsigned long kmap_vstart;
125
126 /* cache the first kmap pte */
127 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
128 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
129}
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 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
38 * no global lock is needed and because the kmap code must perform a global TLB
39 * invalidation when the kmap pool wraps.
40 *
41 * However when holding an atomic kmap is is not legal to sleep, so atomic
42 * kmaps are appropriate for short, tight code paths only.
43 */
44
45void *kmap_atomic(struct page *page)
46{
47 unsigned long vaddr;
48 int idx, type;
49
50 /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
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) { // FIXME
74 pagefault_enable();
75 return;
76 }
77
78 type = kmap_atomic_idx();
79#ifdef CONFIG_DEBUG_HIGHMEM
80 {
81 int idx = type + KM_TYPE_NR * smp_processor_id();
82
83 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
84
85 /*
86 * force other mappings to Oops if they'll try to access
87 * this pte without first remap it
88 */
89 pte_clear(&init_mm, vaddr, kmap_pte-idx);
90 local_flush_tlb_one(vaddr);
91 }
92#endif
93 kmap_atomic_idx_pop();
94 pagefault_enable();
95}
96EXPORT_SYMBOL(__kunmap_atomic);
97
98/*
99 * This is the same as kmap_atomic() but can map memory that doesn't
100 * have a struct page associated with it.
101 */
102void *kmap_atomic_pfn(unsigned long pfn)
103{
104 unsigned long vaddr;
105 int idx, type;
106
107 pagefault_disable();
108
109 type = kmap_atomic_idx_push();
110 idx = type + KM_TYPE_NR*smp_processor_id();
111 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
112 set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
113 flush_tlb_one(vaddr);
114
115 return (void*) vaddr;
116}
117
118struct page *kmap_atomic_to_page(void *ptr)
119{
120 unsigned long idx, vaddr = (unsigned long)ptr;
121 pte_t *pte;
122
123 if (vaddr < FIXADDR_START)
124 return virt_to_page(ptr);
125
126 idx = virt_to_fix(vaddr);
127 pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
128 return pte_page(*pte);
129}
130
131void __init kmap_init(void)
132{
133 unsigned long kmap_vstart;
134
135 /* cache the first kmap pte */
136 kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
137 kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
138}