summaryrefslogtreecommitdiffstats
path: root/include/linux/highmem-internal.h
blob: 0a0b2b09b1b8dbe568cbd22c99405208d4110c6f (plain)
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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_HIGHMEM_INTERNAL_H
#define _LINUX_HIGHMEM_INTERNAL_H

/*
 * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
 */
#ifdef CONFIG_KMAP_LOCAL
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
void kunmap_local_indexed(void *vaddr);
void kmap_local_fork(struct task_struct *tsk);
void __kmap_local_sched_out(void);
void __kmap_local_sched_in(void);
static inline void kmap_assert_nomap(void)
{
	DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
}
#else
static inline void kmap_local_fork(struct task_struct *tsk) { }
static inline void kmap_assert_nomap(void) { }
#endif

#ifdef CONFIG_HIGHMEM
#include <asm/highmem.h>

#ifndef ARCH_HAS_KMAP_FLUSH_TLB
static inline void kmap_flush_tlb(unsigned long addr) { }
#endif

#ifndef kmap_prot
#define kmap_prot PAGE_KERNEL
#endif

void *kmap_high(struct page *page);
void kunmap_high(struct page *page);
void __kmap_flush_unused(void);
struct page *__kmap_to_page(void *addr);

static inline void *kmap(struct page *page)
{
	void *addr;

	might_sleep();
	if (!PageHighMem(page))
		addr = page_address(page);
	else
		addr = kmap_high(page);
	kmap_flush_tlb((unsigned long)addr);
	return addr;
}

static inline void kunmap(struct page *page)
{
	might_sleep();
	if (!PageHighMem(page))
		return;
	kunmap_high(page);
}

static inline struct page *kmap_to_page(void *addr)
{
	return __kmap_to_page(addr);
}

static inline void kmap_flush_unused(void)
{
	__kmap_flush_unused();
}

static inline void *kmap_local_page(struct page *page)
{
	return __kmap_local_page_prot(page, kmap_prot);
}

static inline void *kmap_local_folio(struct folio *folio, size_t offset)
{
	struct page *page = folio_page(folio, offset / PAGE_SIZE);
	return __kmap_local_page_prot(page, kmap_prot) + offset % PAGE_SIZE;
}

static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
{
	return __kmap_local_page_prot(page, prot);
}

static inline void *kmap_local_pfn(unsigned long pfn)
{
	return __kmap_local_pfn_prot(pfn, kmap_prot);
}

static inline void __kunmap_local(void *vaddr)
{
	kunmap_local_indexed(vaddr);
}

static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
	if (IS_ENABLED(CONFIG_PREEMPT_RT))
		migrate_disable();
	else
		preempt_disable();

	pagefault_disable();
	return __kmap_local_page_prot(page, prot);
}

static inline void *kmap_atomic(struct page *page)
{
	return kmap_atomic_prot(page, kmap_prot);
}

static inline void *kmap_atomic_pfn(unsigned long pfn)
{
	if (IS_ENABLED(CONFIG_PREEMPT_RT))
		migrate_disable();
	else
		preempt_disable();

	pagefault_disable();
	return __kmap_local_pfn_prot(pfn, kmap_prot);
}

static inline void __kunmap_atomic(void *addr)
{
	kunmap_local_indexed(addr);
	pagefault_enable();
	if (IS_ENABLED(CONFIG_PREEMPT_RT))
		migrate_enable();
	else
		preempt_enable();
}

unsigned int __nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;

static inline unsigned int nr_free_highpages(void)
{
	return __nr_free_highpages();
}

static inline unsigned long totalhigh_pages(void)
{
	return (unsigned long)atomic_long_read(&_totalhigh_pages);
}

static inline void totalhigh_pages_add(long count)
{
	atomic_long_add(count, &_totalhigh_pages);
}

#else /* CONFIG_HIGHMEM */

static inline struct page *kmap_to_page(void *addr)
{
	return virt_to_page(addr);
}

static inline void *kmap(struct page *page)
{
	might_sleep();
	return page_address(page);
}

static inline void kunmap_high(struct page *page) { }
static inline void kmap_flush_unused(void) { }

static inline void kunmap(struct page *page)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
	kunmap_flush_on_unmap(page_address(page));
#endif
}

static inline void *kmap_local_page(struct page *page)
{
	return page_address(page);
}

static inline void *kmap_local_folio(struct folio *folio, size_t offset)
{
	return page_address(&folio->page) + offset;
}

static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
{
	return kmap_local_page(page);
}

static inline void *kmap_local_pfn(unsigned long pfn)
{
	return kmap_local_page(pfn_to_page(pfn));
}

static inline void __kunmap_local(void *addr)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
	kunmap_flush_on_unmap(addr);
#endif
}

static inline void *kmap_atomic(struct page *page)
{
	if (IS_ENABLED(CONFIG_PREEMPT_RT))
		migrate_disable();
	else
		preempt_disable();
	pagefault_disable();
	return page_address(page);
}

static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
	return kmap_atomic(page);
}

static inline void *kmap_atomic_pfn(unsigned long pfn)
{
	return kmap_atomic(pfn_to_page(pfn));
}

static inline void __kunmap_atomic(void *addr)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
	kunmap_flush_on_unmap(addr);
#endif
	pagefault_enable();
	if (IS_ENABLED(CONFIG_PREEMPT_RT))
		migrate_enable();
	else
		preempt_enable();
}

static inline unsigned int nr_free_highpages(void) { return 0; }
static inline unsigned long totalhigh_pages(void) { return 0UL; }

#endif /* CONFIG_HIGHMEM */

/*
 * Prevent people trying to call kunmap_atomic() as if it were kunmap()
 * kunmap_atomic() should get the return value of kmap_atomic, not the page.
 */
#define kunmap_atomic(__addr)					\
do {								\
	BUILD_BUG_ON(__same_type((__addr), struct page *));	\
	__kunmap_atomic(__addr);				\
} while (0)

#define kunmap_local(__addr)					\
do {								\
	BUILD_BUG_ON(__same_type((__addr), struct page *));	\
	__kunmap_local(__addr);					\
} while (0)

#endif