Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_HIGHMEM_INTERNAL_H
3#define _LINUX_HIGHMEM_INTERNAL_H
4
5/*
6 * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
7 */
8#ifdef CONFIG_KMAP_LOCAL
9void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
10void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
11void kunmap_local_indexed(void *vaddr);
12void kmap_local_fork(struct task_struct *tsk);
13void __kmap_local_sched_out(void);
14void __kmap_local_sched_in(void);
15static inline void kmap_assert_nomap(void)
16{
17 DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
18}
19#else
20static inline void kmap_local_fork(struct task_struct *tsk) { }
21static inline void kmap_assert_nomap(void) { }
22#endif
23
24#ifdef CONFIG_HIGHMEM
25#include <asm/highmem.h>
26
27#ifndef ARCH_HAS_KMAP_FLUSH_TLB
28static inline void kmap_flush_tlb(unsigned long addr) { }
29#endif
30
31#ifndef kmap_prot
32#define kmap_prot PAGE_KERNEL
33#endif
34
35void *kmap_high(struct page *page);
36void kunmap_high(struct page *page);
37void __kmap_flush_unused(void);
38struct page *__kmap_to_page(void *addr);
39
40static inline void *kmap(struct page *page)
41{
42 void *addr;
43
44 might_sleep();
45 if (!PageHighMem(page))
46 addr = page_address(page);
47 else
48 addr = kmap_high(page);
49 kmap_flush_tlb((unsigned long)addr);
50 return addr;
51}
52
53static inline void kunmap(struct page *page)
54{
55 might_sleep();
56 if (!PageHighMem(page))
57 return;
58 kunmap_high(page);
59}
60
61static inline struct page *kmap_to_page(void *addr)
62{
63 return __kmap_to_page(addr);
64}
65
66static inline void kmap_flush_unused(void)
67{
68 __kmap_flush_unused();
69}
70
71static inline void *kmap_local_page(struct page *page)
72{
73 return __kmap_local_page_prot(page, kmap_prot);
74}
75
76static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
77{
78 return __kmap_local_page_prot(page, prot);
79}
80
81static inline void *kmap_local_pfn(unsigned long pfn)
82{
83 return __kmap_local_pfn_prot(pfn, kmap_prot);
84}
85
86static inline void __kunmap_local(void *vaddr)
87{
88 kunmap_local_indexed(vaddr);
89}
90
91static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
92{
93 if (IS_ENABLED(CONFIG_PREEMPT_RT))
94 migrate_disable();
95 else
96 preempt_disable();
97
98 pagefault_disable();
99 return __kmap_local_page_prot(page, prot);
100}
101
102static inline void *kmap_atomic(struct page *page)
103{
104 return kmap_atomic_prot(page, kmap_prot);
105}
106
107static inline void *kmap_atomic_pfn(unsigned long pfn)
108{
109 if (IS_ENABLED(CONFIG_PREEMPT_RT))
110 migrate_disable();
111 else
112 preempt_disable();
113
114 pagefault_disable();
115 return __kmap_local_pfn_prot(pfn, kmap_prot);
116}
117
118static inline void __kunmap_atomic(void *addr)
119{
120 kunmap_local_indexed(addr);
121 pagefault_enable();
122 if (IS_ENABLED(CONFIG_PREEMPT_RT))
123 migrate_enable();
124 else
125 preempt_enable();
126}
127
128unsigned int __nr_free_highpages(void);
129extern atomic_long_t _totalhigh_pages;
130
131static inline unsigned int nr_free_highpages(void)
132{
133 return __nr_free_highpages();
134}
135
136static inline unsigned long totalhigh_pages(void)
137{
138 return (unsigned long)atomic_long_read(&_totalhigh_pages);
139}
140
141static inline void totalhigh_pages_add(long count)
142{
143 atomic_long_add(count, &_totalhigh_pages);
144}
145
146#else /* CONFIG_HIGHMEM */
147
148static inline struct page *kmap_to_page(void *addr)
149{
150 return virt_to_page(addr);
151}
152
153static inline void *kmap(struct page *page)
154{
155 might_sleep();
156 return page_address(page);
157}
158
159static inline void kunmap_high(struct page *page) { }
160static inline void kmap_flush_unused(void) { }
161
162static inline void kunmap(struct page *page)
163{
164#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
165 kunmap_flush_on_unmap(page_address(page));
166#endif
167}
168
169static inline void *kmap_local_page(struct page *page)
170{
171 return page_address(page);
172}
173
174static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
175{
176 return kmap_local_page(page);
177}
178
179static inline void *kmap_local_pfn(unsigned long pfn)
180{
181 return kmap_local_page(pfn_to_page(pfn));
182}
183
184static inline void __kunmap_local(void *addr)
185{
186#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
187 kunmap_flush_on_unmap(addr);
188#endif
189}
190
191static inline void *kmap_atomic(struct page *page)
192{
193 if (IS_ENABLED(CONFIG_PREEMPT_RT))
194 migrate_disable();
195 else
196 preempt_disable();
197 pagefault_disable();
198 return page_address(page);
199}
200
201static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
202{
203 return kmap_atomic(page);
204}
205
206static inline void *kmap_atomic_pfn(unsigned long pfn)
207{
208 return kmap_atomic(pfn_to_page(pfn));
209}
210
211static inline void __kunmap_atomic(void *addr)
212{
213#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
214 kunmap_flush_on_unmap(addr);
215#endif
216 pagefault_enable();
217 if (IS_ENABLED(CONFIG_PREEMPT_RT))
218 migrate_enable();
219 else
220 preempt_enable();
221}
222
223static inline unsigned int nr_free_highpages(void) { return 0; }
224static inline unsigned long totalhigh_pages(void) { return 0UL; }
225
226#endif /* CONFIG_HIGHMEM */
227
228/*
229 * Prevent people trying to call kunmap_atomic() as if it were kunmap()
230 * kunmap_atomic() should get the return value of kmap_atomic, not the page.
231 */
232#define kunmap_atomic(__addr) \
233do { \
234 BUILD_BUG_ON(__same_type((__addr), struct page *)); \
235 __kunmap_atomic(__addr); \
236} while (0)
237
238#define kunmap_local(__addr) \
239do { \
240 BUILD_BUG_ON(__same_type((__addr), struct page *)); \
241 __kunmap_local(__addr); \
242} while (0)
243
244#endif