include/linux/highmem-internal.h

   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(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);
  15 static inline void kmap_assert_nomap(void)
  16 {
  17         DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
  18 }
  19 #else
  20 static inline void kmap_local_fork(struct task_struct *tsk) { }
  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
  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
  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
  53 static inline void kunmap(struct page *page)
  54 {
  55         might_sleep();
  56         if (!PageHighMem(page))
  57                 return;
  58         kunmap_high(page);
  59 }
  60
  61 static inline struct page *kmap_to_page(void *addr)
  62 {
  63         return __kmap_to_page(addr);
  64 }
  65
  66 static inline void kmap_flush_unused(void)
  67 {
  68         __kmap_flush_unused();
  69 }
  70
  71 static inline void *kmap_local_page(struct page *page)
  72 {
  73         return __kmap_local_page_prot(page, kmap_prot);
  74 }
  75
  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
  81 static inline void *kmap_local_pfn(unsigned long pfn)
  82 {
  83         return __kmap_local_pfn_prot(pfn, kmap_prot);
  84 }
  85
  86 static inline void __kunmap_local(void *vaddr)
  87 {
  88         kunmap_local_indexed(vaddr);
  89 }
  90
  91 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
  92 {
  93         preempt_disable();
  94         pagefault_disable();
  95         return __kmap_local_page_prot(page, prot);
  96 }
  97
  98 static inline void *kmap_atomic(struct page *page)
  99 {
 100         return kmap_atomic_prot(page, kmap_prot);
 101 }
 102
 103 static inline void *kmap_atomic_pfn(unsigned long pfn)
 104 {
 105         preempt_disable();
 106         pagefault_disable();
 107         return __kmap_local_pfn_prot(pfn, kmap_prot);
 108 }
 109
 110 static inline void __kunmap_atomic(void *addr)
 111 {
 112         kunmap_local_indexed(addr);
 113         pagefault_enable();
 114         preempt_enable();
 115 }
 116
 117 unsigned int __nr_free_highpages(void);
 118 extern atomic_long_t _totalhigh_pages;
 119
 120 static inline unsigned int nr_free_highpages(void)
 121 {
 122         return __nr_free_highpages();
 123 }
 124
 125 static inline unsigned long totalhigh_pages(void)
 126 {
 127         return (unsigned long)atomic_long_read(&_totalhigh_pages);
 128 }
 129
 130 static inline void totalhigh_pages_add(long count)
 131 {
 132         atomic_long_add(count, &_totalhigh_pages);
 133 }
 134
 135 #else /* CONFIG_HIGHMEM */
 136
 137 static inline struct page *kmap_to_page(void *addr)
 138 {
 139         return virt_to_page(addr);
 140 }
 141
 142 static inline void *kmap(struct page *page)
 143 {
 144         might_sleep();
 145         return page_address(page);
 146 }
 147
 148 static inline void kunmap_high(struct page *page) { }
 149 static inline void kmap_flush_unused(void) { }
 150
 151 static inline void kunmap(struct page *page)
 152 {
 153 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
 154         kunmap_flush_on_unmap(page_address(page));
 155 #endif
 156 }
 157
 158 static inline void *kmap_local_page(struct page *page)
 159 {
 160         return page_address(page);
 161 }
 162
 163 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
 164 {
 165         return kmap_local_page(page);
 166 }
 167
 168 static inline void *kmap_local_pfn(unsigned long pfn)
 169 {
 170         return kmap_local_page(pfn_to_page(pfn));
 171 }
 172
 173 static inline void __kunmap_local(void *addr)
 174 {
 175 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
 176         kunmap_flush_on_unmap(addr);
 177 #endif
 178 }
 179
 180 static inline void *kmap_atomic(struct page *page)
 181 {
 182         preempt_disable();
 183         pagefault_disable();
 184         return page_address(page);
 185 }
 186
 187 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 188 {
 189         return kmap_atomic(page);
 190 }
 191
 192 static inline void *kmap_atomic_pfn(unsigned long pfn)
 193 {
 194         return kmap_atomic(pfn_to_page(pfn));
 195 }
 196
 197 static inline void __kunmap_atomic(void *addr)
 198 {
 199 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
 200         kunmap_flush_on_unmap(addr);
 201 #endif
 202         pagefault_enable();
 203         preempt_enable();
 204 }
 205
 206 static inline unsigned int nr_free_highpages(void) { return 0; }
 207 static inline unsigned long totalhigh_pages(void) { return 0UL; }
 208
 209 #endif /* CONFIG_HIGHMEM */
 210
 211 /*
 212  * Prevent people trying to call kunmap_atomic() as if it were kunmap()
 213  * kunmap_atomic() should get the return value of kmap_atomic, not the page.
 214  */
 215 #define kunmap_atomic(__addr)                                   \
 216 do {                                                            \
 217         BUILD_BUG_ON(__same_type((__addr), struct page *));     \
 218         __kunmap_atomic(__addr);                                \
 219 } while (0)
 220
 221 #define kunmap_local(__addr)                                    \
 222 do {                                                            \
 223         BUILD_BUG_ON(__same_type((__addr), struct page *));     \
 224         __kunmap_local(__addr);                                 \
 225 } while (0)
 226
 227 #endif