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_atomic_prot(struct page *page, pgprot_t prot) 72 { 73 preempt_disable(); 74 pagefault_disable(); 75 return __kmap_local_page_prot(page, prot); 76 } 77 78 static inline void *kmap_atomic(struct page *page) 79 { 80 return kmap_atomic_prot(page, kmap_prot); 81 } 82 83 static inline void *kmap_atomic_pfn(unsigned long pfn) 84 { 85 preempt_disable(); 86 pagefault_disable(); 87 return __kmap_local_pfn_prot(pfn, kmap_prot); 88 } 89 90 static inline void __kunmap_atomic(void *addr) 91 { 92 kunmap_local_indexed(addr); 93 pagefault_enable(); 94 preempt_enable(); 95 } 96 97 unsigned int __nr_free_highpages(void); 98 extern atomic_long_t _totalhigh_pages; 99 100 static inline unsigned int nr_free_highpages(void) 101 { 102 return __nr_free_highpages(); 103 } 104 105 static inline unsigned long totalhigh_pages(void) 106 { 107 return (unsigned long)atomic_long_read(&_totalhigh_pages); 108 } 109 110 static inline void totalhigh_pages_inc(void) 111 { 112 atomic_long_inc(&_totalhigh_pages); 113 } 114 115 static inline void totalhigh_pages_add(long count) 116 { 117 atomic_long_add(count, &_totalhigh_pages); 118 } 119 120 #else /* CONFIG_HIGHMEM */ 121 122 static inline struct page *kmap_to_page(void *addr) 123 { 124 return virt_to_page(addr); 125 } 126 127 static inline void *kmap(struct page *page) 128 { 129 might_sleep(); 130 return page_address(page); 131 } 132 133 static inline void kunmap_high(struct page *page) { } 134 static inline void kmap_flush_unused(void) { } 135 136 static inline void kunmap(struct page *page) 137 { 138 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP 139 kunmap_flush_on_unmap(page_address(page)); 140 #endif 141 } 142 143 static inline void *kmap_atomic(struct page *page) 144 { 145 preempt_disable(); 146 pagefault_disable(); 147 return page_address(page); 148 } 149 150 static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) 151 { 152 return kmap_atomic(page); 153 } 154 155 static inline void *kmap_atomic_pfn(unsigned long pfn) 156 { 157 return kmap_atomic(pfn_to_page(pfn)); 158 } 159 160 static inline void __kunmap_atomic(void *addr) 161 { 162 #ifdef ARCH_HAS_FLUSH_ON_KUNMAP 163 kunmap_flush_on_unmap(addr); 164 #endif 165 pagefault_enable(); 166 preempt_enable(); 167 } 168 169 static inline unsigned int nr_free_highpages(void) { return 0; } 170 static inline unsigned long totalhigh_pages(void) { return 0UL; } 171 172 #endif /* CONFIG_HIGHMEM */ 173 174 /* 175 * Prevent people trying to call kunmap_atomic() as if it were kunmap() 176 * kunmap_atomic() should get the return value of kmap_atomic, not the page. 177 */ 178 #define kunmap_atomic(__addr) \ 179 do { \ 180 BUILD_BUG_ON(__same_type((__addr), struct page *)); \ 181 __kunmap_atomic(__addr); \ 182 } while (0) 183 184 #endif 185