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
9 void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
10 void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
11 void kunmap_local_indexed(const void *vaddr);
12 void kmap_local_fork(struct task_struct *tsk);
13 void __kmap_local_sched_out(void);
14 void __kmap_local_sched_in(void);
kmap_assert_nomap(void)15 static inline void kmap_assert_nomap(void)
16 {
17 DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
18 }
19 #else
kmap_local_fork(struct task_struct * tsk)20 static inline void kmap_local_fork(struct task_struct *tsk) { }
kmap_assert_nomap(void)21 static 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
kmap_flush_tlb(unsigned long addr)28 static inline void kmap_flush_tlb(unsigned long addr) { }
29 #endif
30
31 #ifndef kmap_prot
32 #define kmap_prot PAGE_KERNEL
33 #endif
34
35 void *kmap_high(struct page *page);
36 void kunmap_high(struct page *page);
37 void __kmap_flush_unused(void);
38 struct page *__kmap_to_page(void *addr);
39
kmap(struct page * page)40 static 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
kunmap(struct page * page)53 static inline void kunmap(struct page *page)
54 {
55 might_sleep();
56 if (!PageHighMem(page))
57 return;
58 kunmap_high(page);
59 }
60
kmap_to_page(void * addr)61 static inline struct page *kmap_to_page(void *addr)
62 {
63 return __kmap_to_page(addr);
64 }
65
kmap_flush_unused(void)66 static inline void kmap_flush_unused(void)
67 {
68 __kmap_flush_unused();
69 }
70
kmap_local_page(struct page * page)71 static inline void *kmap_local_page(struct page *page)
72 {
73 return __kmap_local_page_prot(page, kmap_prot);
74 }
75
kmap_local_page_prot(struct page * page,pgprot_t prot)76 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
77 {
78 return __kmap_local_page_prot(page, prot);
79 }
80
kmap_local_pfn(unsigned long pfn)81 static inline void *kmap_local_pfn(unsigned long pfn)
82 {
83 return __kmap_local_pfn_prot(pfn, kmap_prot);
84 }
85
__kunmap_local(const void * vaddr)86 static inline void __kunmap_local(const void *vaddr)
87 {
88 kunmap_local_indexed(vaddr);
89 }
90
kmap_atomic_prot(struct page * page,pgprot_t prot)91 static 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
kmap_atomic(struct page * page)102 static inline void *kmap_atomic(struct page *page)
103 {
104 return kmap_atomic_prot(page, kmap_prot);
105 }
106
kmap_atomic_pfn(unsigned long pfn)107 static 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
__kunmap_atomic(const void * addr)118 static inline void __kunmap_atomic(const 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
128 unsigned int __nr_free_highpages(void);
129 extern atomic_long_t _totalhigh_pages;
130
nr_free_highpages(void)131 static inline unsigned int nr_free_highpages(void)
132 {
133 return __nr_free_highpages();
134 }
135
totalhigh_pages(void)136 static inline unsigned long totalhigh_pages(void)
137 {
138 return (unsigned long)atomic_long_read(&_totalhigh_pages);
139 }
140
totalhigh_pages_add(long count)141 static inline void totalhigh_pages_add(long count)
142 {
143 atomic_long_add(count, &_totalhigh_pages);
144 }
145
146 #else /* CONFIG_HIGHMEM */
147
kmap_to_page(void * addr)148 static inline struct page *kmap_to_page(void *addr)
149 {
150 return virt_to_page(addr);
151 }
152
kmap(struct page * page)153 static inline void *kmap(struct page *page)
154 {
155 might_sleep();
156 return page_address(page);
157 }
158
kunmap_high(struct page * page)159 static inline void kunmap_high(struct page *page) { }
kmap_flush_unused(void)160 static inline void kmap_flush_unused(void) { }
161
kunmap(struct page * page)162 static 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
kmap_local_page(struct page * page)169 static inline void *kmap_local_page(struct page *page)
170 {
171 return page_address(page);
172 }
173
kmap_local_page_prot(struct page * page,pgprot_t prot)174 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
175 {
176 return kmap_local_page(page);
177 }
178
kmap_local_pfn(unsigned long pfn)179 static inline void *kmap_local_pfn(unsigned long pfn)
180 {
181 return kmap_local_page(pfn_to_page(pfn));
182 }
183
__kunmap_local(const void * addr)184 static inline void __kunmap_local(const void *addr)
185 {
186 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
187 kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE));
188 #endif
189 }
190
kmap_atomic(struct page * page)191 static 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
kmap_atomic_prot(struct page * page,pgprot_t prot)201 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
202 {
203 return kmap_atomic(page);
204 }
205
kmap_atomic_pfn(unsigned long pfn)206 static inline void *kmap_atomic_pfn(unsigned long pfn)
207 {
208 return kmap_atomic(pfn_to_page(pfn));
209 }
210
__kunmap_atomic(const void * addr)211 static inline void __kunmap_atomic(const void *addr)
212 {
213 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
214 kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE));
215 #endif
216 pagefault_enable();
217 if (IS_ENABLED(CONFIG_PREEMPT_RT))
218 migrate_enable();
219 else
220 preempt_enable();
221 }
222
nr_free_highpages(void)223 static inline unsigned int nr_free_highpages(void) { return 0; }
totalhigh_pages(void)224 static 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) \
233 do { \
234 BUILD_BUG_ON(__same_type((__addr), struct page *)); \
235 __kunmap_atomic(__addr); \
236 } while (0)
237
238 #define kunmap_local(__addr) \
239 do { \
240 BUILD_BUG_ON(__same_type((__addr), struct page *)); \
241 __kunmap_local(__addr); \
242 } while (0)
243
244 #endif
245