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_folio(struct folio *folio, size_t offset) 77 { 78 struct page *page = folio_page(folio, offset / PAGE_SIZE); 79 return __kmap_local_page_prot(page, kmap_prot) + offset % PAGE_SIZE; 80 } 81 82 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot) 83 { 84 return __kmap_local_page_prot(page, prot); 85 } 86 87 static inline void *kmap_local_pfn(unsigned long pfn) 88 { 89 return __kmap_local_pfn_prot(pfn, kmap_prot); 90 } 91 92 static inline void __kunmap_local(void *vaddr) 93 { 94 kunmap_local_indexed(vaddr); 95 } 96 97 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) 98 { 99 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 100 migrate_disable(); 101 else 102 preempt_disable(); 103 104 pagefault_disable(); 105 return __kmap_local_page_prot(page, prot); 106 } 107 108 static inline void *kmap_atomic(struct page *page) 109 { 110 return kmap_atomic_prot(page, kmap_prot); 111 } 112 113 static inline void *kmap_atomic_pfn(unsigned long pfn) 114 { 115 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 116 migrate_disable(); 117 else 118 preempt_disable(); 119 120 pagefault_disable(); 121 return __kmap_local_pfn_prot(pfn, kmap_prot); 122 } 123 124 static inline void __kunmap_atomic(void *addr) 125 { 126 kunmap_local_indexed(addr); 127 pagefault_enable(); 128 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 129 migrate_enable(); 130 else 131 preempt_enable(); 132 } 133 134 unsigned int __nr_free_highpages(void); 135 extern atomic_long_t _totalhigh_pages; 136 137 static inline unsigned int nr_free_highpages(void) 138 { 139 return __nr_free_highpages(); 140 } 141 142 static inline unsigned long totalhigh_pages(void) 143 { 144 return (unsigned long)atomic_long_read(&_totalhigh_pages); 145 } 146 147 static inline void totalhigh_pages_add(long count) 148 { 149 atomic_long_add(count, &_totalhigh_pages); 150 } 151 152 #else /* CONFIG_HIGHMEM */ 153 154 static inline struct page *kmap_to_page(void *addr) 155 { 156 return virt_to_page(addr); 157 } 158 159 static inline void *kmap(struct page *page) 160 { 161 might_sleep(); 162 return page_address(page); 163 } 164 165 static inline void kunmap_high(struct page *page) { } 166 static inline void kmap_flush_unused(void) { } 167 168 static inline void kunmap(struct page *page) 169 { 170 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP 171 kunmap_flush_on_unmap(page_address(page)); 172 #endif 173 } 174 175 static inline void *kmap_local_page(struct page *page) 176 { 177 return page_address(page); 178 } 179 180 static inline void *kmap_local_folio(struct folio *folio, size_t offset) 181 { 182 return page_address(&folio->page) + offset; 183 } 184 185 static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot) 186 { 187 return kmap_local_page(page); 188 } 189 190 static inline void *kmap_local_pfn(unsigned long pfn) 191 { 192 return kmap_local_page(pfn_to_page(pfn)); 193 } 194 195 static inline void __kunmap_local(void *addr) 196 { 197 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP 198 kunmap_flush_on_unmap(addr); 199 #endif 200 } 201 202 static inline void *kmap_atomic(struct page *page) 203 { 204 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 205 migrate_disable(); 206 else 207 preempt_disable(); 208 pagefault_disable(); 209 return page_address(page); 210 } 211 212 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) 213 { 214 return kmap_atomic(page); 215 } 216 217 static inline void *kmap_atomic_pfn(unsigned long pfn) 218 { 219 return kmap_atomic(pfn_to_page(pfn)); 220 } 221 222 static inline void __kunmap_atomic(void *addr) 223 { 224 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP 225 kunmap_flush_on_unmap(addr); 226 #endif 227 pagefault_enable(); 228 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 229 migrate_enable(); 230 else 231 preempt_enable(); 232 } 233 234 static inline unsigned int nr_free_highpages(void) { return 0; } 235 static inline unsigned long totalhigh_pages(void) { return 0UL; } 236 237 #endif /* CONFIG_HIGHMEM */ 238 239 /* 240 * Prevent people trying to call kunmap_atomic() as if it were kunmap() 241 * kunmap_atomic() should get the return value of kmap_atomic, not the page. 242 */ 243 #define kunmap_atomic(__addr) \ 244 do { \ 245 BUILD_BUG_ON(__same_type((__addr), struct page *)); \ 246 __kunmap_atomic(__addr); \ 247 } while (0) 248 249 /** 250 * kunmap_local - Unmap a page mapped via kmap_local_page(). 251 * @__addr: An address within the page mapped 252 * 253 * @__addr can be any address within the mapped page. Commonly it is the 254 * address return from kmap_local_page(), but it can also include offsets. 255 * 256 * Unmapping should be done in the reverse order of the mapping. See 257 * kmap_local_page() for details. 258 */ 259 #define kunmap_local(__addr) \ 260 do { \ 261 BUILD_BUG_ON(__same_type((__addr), struct page *)); \ 262 __kunmap_local(__addr); \ 263 } while (0) 264 265 #endif 266