1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Based on arch/arm/include/asm/cacheflush.h 4 * 5 * Copyright (C) 1999-2002 Russell King. 6 * Copyright (C) 2012 ARM Ltd. 7 */ 8 #ifndef __ASM_CACHEFLUSH_H 9 #define __ASM_CACHEFLUSH_H 10 11 #include <linux/kgdb.h> 12 #include <linux/mm.h> 13 14 /* 15 * This flag is used to indicate that the page pointed to by a pte is clean 16 * and does not require cleaning before returning it to the user. 17 */ 18 #define PG_dcache_clean PG_arch_1 19 20 /* 21 * MM Cache Management 22 * =================== 23 * 24 * The arch/arm64/mm/cache.S implements these methods. 25 * 26 * Start addresses are inclusive and end addresses are exclusive; start 27 * addresses should be rounded down, end addresses up. 28 * 29 * See Documentation/core-api/cachetlb.rst for more information. Please note that 30 * the implementation assumes non-aliasing VIPT D-cache and (aliasing) 31 * VIPT I-cache. 32 * 33 * flush_cache_mm(mm) 34 * 35 * Clean and invalidate all user space cache entries 36 * before a change of page tables. 37 * 38 * flush_icache_range(start, end) 39 * 40 * Ensure coherency between the I-cache and the D-cache in the 41 * region described by start, end. 42 * - start - virtual start address 43 * - end - virtual end address 44 * 45 * invalidate_icache_range(start, end) 46 * 47 * Invalidate the I-cache in the region described by start, end. 48 * - start - virtual start address 49 * - end - virtual end address 50 * 51 * __flush_cache_user_range(start, end) 52 * 53 * Ensure coherency between the I-cache and the D-cache in the 54 * region described by start, end. 55 * - start - virtual start address 56 * - end - virtual end address 57 * 58 * __flush_dcache_area(kaddr, size) 59 * 60 * Ensure that the data held in page is written back. 61 * - kaddr - page address 62 * - size - region size 63 */ 64 extern void __flush_icache_range(unsigned long start, unsigned long end); 65 extern int invalidate_icache_range(unsigned long start, unsigned long end); 66 extern void __flush_dcache_area(void *addr, size_t len); 67 extern void __inval_dcache_area(void *addr, size_t len); 68 extern void __clean_dcache_area_poc(void *addr, size_t len); 69 extern void __clean_dcache_area_pop(void *addr, size_t len); 70 extern void __clean_dcache_area_pou(void *addr, size_t len); 71 extern long __flush_cache_user_range(unsigned long start, unsigned long end); 72 extern void sync_icache_aliases(void *kaddr, unsigned long len); 73 74 static inline void flush_icache_range(unsigned long start, unsigned long end) 75 { 76 __flush_icache_range(start, end); 77 78 /* 79 * IPI all online CPUs so that they undergo a context synchronization 80 * event and are forced to refetch the new instructions. 81 */ 82 #ifdef CONFIG_KGDB 83 /* 84 * KGDB performs cache maintenance with interrupts disabled, so we 85 * will deadlock trying to IPI the secondary CPUs. In theory, we can 86 * set CACHE_FLUSH_IS_SAFE to 0 to avoid this known issue, but that 87 * just means that KGDB will elide the maintenance altogether! As it 88 * turns out, KGDB uses IPIs to round-up the secondary CPUs during 89 * the patching operation, so we don't need extra IPIs here anyway. 90 * In which case, add a KGDB-specific bodge and return early. 91 */ 92 if (kgdb_connected && irqs_disabled()) 93 return; 94 #endif 95 kick_all_cpus_sync(); 96 } 97 98 static inline void flush_cache_mm(struct mm_struct *mm) 99 { 100 } 101 102 static inline void flush_cache_page(struct vm_area_struct *vma, 103 unsigned long user_addr, unsigned long pfn) 104 { 105 } 106 107 static inline void flush_cache_range(struct vm_area_struct *vma, 108 unsigned long start, unsigned long end) 109 { 110 } 111 112 /* 113 * Cache maintenance functions used by the DMA API. No to be used directly. 114 */ 115 extern void __dma_map_area(const void *, size_t, int); 116 extern void __dma_unmap_area(const void *, size_t, int); 117 extern void __dma_flush_area(const void *, size_t); 118 119 /* 120 * Copy user data from/to a page which is mapped into a different 121 * processes address space. Really, we want to allow our "user 122 * space" model to handle this. 123 */ 124 extern void copy_to_user_page(struct vm_area_struct *, struct page *, 125 unsigned long, void *, const void *, unsigned long); 126 #define copy_from_user_page(vma, page, vaddr, dst, src, len) \ 127 do { \ 128 memcpy(dst, src, len); \ 129 } while (0) 130 131 #define flush_cache_dup_mm(mm) flush_cache_mm(mm) 132 133 /* 134 * flush_dcache_page is used when the kernel has written to the page 135 * cache page at virtual address page->virtual. 136 * 137 * If this page isn't mapped (ie, page_mapping == NULL), or it might 138 * have userspace mappings, then we _must_ always clean + invalidate 139 * the dcache entries associated with the kernel mapping. 140 * 141 * Otherwise we can defer the operation, and clean the cache when we are 142 * about to change to user space. This is the same method as used on SPARC64. 143 * See update_mmu_cache for the user space part. 144 */ 145 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1 146 extern void flush_dcache_page(struct page *); 147 148 static __always_inline void __flush_icache_all(void) 149 { 150 if (cpus_have_const_cap(ARM64_HAS_CACHE_DIC)) 151 return; 152 153 asm("ic ialluis"); 154 dsb(ish); 155 } 156 157 #define flush_dcache_mmap_lock(mapping) do { } while (0) 158 #define flush_dcache_mmap_unlock(mapping) do { } while (0) 159 160 /* 161 * We don't appear to need to do anything here. In fact, if we did, we'd 162 * duplicate cache flushing elsewhere performed by flush_dcache_page(). 163 */ 164 #define flush_icache_page(vma,page) do { } while (0) 165 166 /* 167 * Not required on AArch64 (PIPT or VIPT non-aliasing D-cache). 168 */ 169 static inline void flush_cache_vmap(unsigned long start, unsigned long end) 170 { 171 } 172 173 static inline void flush_cache_vunmap(unsigned long start, unsigned long end) 174 { 175 } 176 177 int set_memory_valid(unsigned long addr, int numpages, int enable); 178 179 int set_direct_map_invalid_noflush(struct page *page); 180 int set_direct_map_default_noflush(struct page *page); 181 182 #endif 183