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(const 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_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 82static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot) 83{ 84 return __kmap_local_page_prot(page, prot); 85} 86 87static inline void *kmap_local_pfn(unsigned long pfn) 88{ 89 return __kmap_local_pfn_prot(pfn, kmap_prot); 90} 91 92static inline void __kunmap_local(const void *vaddr) 93{ 94 kunmap_local_indexed(vaddr); 95} 96 97static 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 108static inline void *kmap_atomic(struct page *page) 109{ 110 return kmap_atomic_prot(page, kmap_prot); 111} 112 113static 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 124static inline void __kunmap_atomic(const 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 134unsigned int __nr_free_highpages(void); 135extern atomic_long_t _totalhigh_pages; 136 137static inline unsigned int nr_free_highpages(void) 138{ 139 return __nr_free_highpages(); 140} 141 142static inline unsigned long totalhigh_pages(void) 143{ 144 return (unsigned long)atomic_long_read(&_totalhigh_pages); 145} 146 147static inline void totalhigh_pages_add(long count) 148{ 149 atomic_long_add(count, &_totalhigh_pages); 150} 151 152static inline bool is_kmap_addr(const void *x) 153{ 154 unsigned long addr = (unsigned long)x; 155 156 return (addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP)) || 157 (addr >= __fix_to_virt(FIX_KMAP_END) && 158 addr < __fix_to_virt(FIX_KMAP_BEGIN)); 159} 160#else /* CONFIG_HIGHMEM */ 161 162static inline struct page *kmap_to_page(void *addr) 163{ 164 return virt_to_page(addr); 165} 166 167static inline void *kmap(struct page *page) 168{ 169 might_sleep(); 170 return page_address(page); 171} 172 173static inline void kunmap_high(struct page *page) { } 174static inline void kmap_flush_unused(void) { } 175 176static inline void kunmap(struct page *page) 177{ 178#ifdef ARCH_HAS_FLUSH_ON_KUNMAP 179 kunmap_flush_on_unmap(page_address(page)); 180#endif 181} 182 183static inline void *kmap_local_page(struct page *page) 184{ 185 return page_address(page); 186} 187 188static inline void *kmap_local_folio(struct folio *folio, size_t offset) 189{ 190 return page_address(&folio->page) + offset; 191} 192 193static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot) 194{ 195 return kmap_local_page(page); 196} 197 198static inline void *kmap_local_pfn(unsigned long pfn) 199{ 200 return kmap_local_page(pfn_to_page(pfn)); 201} 202 203static inline void __kunmap_local(const void *addr) 204{ 205#ifdef ARCH_HAS_FLUSH_ON_KUNMAP 206 kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE)); 207#endif 208} 209 210static inline void *kmap_atomic(struct page *page) 211{ 212 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 213 migrate_disable(); 214 else 215 preempt_disable(); 216 pagefault_disable(); 217 return page_address(page); 218} 219 220static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) 221{ 222 return kmap_atomic(page); 223} 224 225static inline void *kmap_atomic_pfn(unsigned long pfn) 226{ 227 return kmap_atomic(pfn_to_page(pfn)); 228} 229 230static inline void __kunmap_atomic(const void *addr) 231{ 232#ifdef ARCH_HAS_FLUSH_ON_KUNMAP 233 kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE)); 234#endif 235 pagefault_enable(); 236 if (IS_ENABLED(CONFIG_PREEMPT_RT)) 237 migrate_enable(); 238 else 239 preempt_enable(); 240} 241 242static inline unsigned int nr_free_highpages(void) { return 0; } 243static inline unsigned long totalhigh_pages(void) { return 0UL; } 244 245static inline bool is_kmap_addr(const void *x) 246{ 247 return false; 248} 249 250#endif /* CONFIG_HIGHMEM */ 251 252/** 253 * kunmap_atomic - Unmap the virtual address mapped by kmap_atomic() - deprecated! 254 * @__addr: Virtual address to be unmapped 255 * 256 * Unmaps an address previously mapped by kmap_atomic() and re-enables 257 * pagefaults. Depending on PREEMP_RT configuration, re-enables also 258 * migration and preemption. Users should not count on these side effects. 259 * 260 * Mappings should be unmapped in the reverse order that they were mapped. 261 * See kmap_local_page() for details on nesting. 262 * 263 * @__addr can be any address within the mapped page, so there is no need 264 * to subtract any offset that has been added. In contrast to kunmap(), 265 * this function takes the address returned from kmap_atomic(), not the 266 * page passed to it. The compiler will warn you if you pass the page. 267 */ 268#define kunmap_atomic(__addr) \ 269do { \ 270 BUILD_BUG_ON(__same_type((__addr), struct page *)); \ 271 __kunmap_atomic(__addr); \ 272} while (0) 273 274/** 275 * kunmap_local - Unmap a page mapped via kmap_local_page(). 276 * @__addr: An address within the page mapped 277 * 278 * @__addr can be any address within the mapped page. Commonly it is the 279 * address return from kmap_local_page(), but it can also include offsets. 280 * 281 * Unmapping should be done in the reverse order of the mapping. See 282 * kmap_local_page() for details. 283 */ 284#define kunmap_local(__addr) \ 285do { \ 286 BUILD_BUG_ON(__same_type((__addr), struct page *)); \ 287 __kunmap_local(__addr); \ 288} while (0) 289 290#endif 291