1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_IA64_TLB_H 3 #define _ASM_IA64_TLB_H 4 /* 5 * Based on <asm-generic/tlb.h>. 6 * 7 * Copyright (C) 2002-2003 Hewlett-Packard Co 8 * David Mosberger-Tang <davidm@hpl.hp.com> 9 */ 10 /* 11 * Removing a translation from a page table (including TLB-shootdown) is a four-step 12 * procedure: 13 * 14 * (1) Flush (virtual) caches --- ensures virtual memory is coherent with kernel memory 15 * (this is a no-op on ia64). 16 * (2) Clear the relevant portions of the page-table 17 * (3) Flush the TLBs --- ensures that stale content is gone from CPU TLBs 18 * (4) Release the pages that were freed up in step (2). 19 * 20 * Note that the ordering of these steps is crucial to avoid races on MP machines. 21 * 22 * The Linux kernel defines several platform-specific hooks for TLB-shootdown. When 23 * unmapping a portion of the virtual address space, these hooks are called according to 24 * the following template: 25 * 26 * tlb <- tlb_gather_mmu(mm, start, end); // start unmap for address space MM 27 * { 28 * for each vma that needs a shootdown do { 29 * tlb_start_vma(tlb, vma); 30 * for each page-table-entry PTE that needs to be removed do { 31 * tlb_remove_tlb_entry(tlb, pte, address); 32 * if (pte refers to a normal page) { 33 * tlb_remove_page(tlb, page); 34 * } 35 * } 36 * tlb_end_vma(tlb, vma); 37 * } 38 * } 39 * tlb_finish_mmu(tlb, start, end); // finish unmap for address space MM 40 */ 41 #include <linux/mm.h> 42 #include <linux/pagemap.h> 43 #include <linux/swap.h> 44 45 #include <asm/pgalloc.h> 46 #include <asm/processor.h> 47 #include <asm/tlbflush.h> 48 #include <asm/machvec.h> 49 50 /* 51 * If we can't allocate a page to make a big batch of page pointers 52 * to work on, then just handle a few from the on-stack structure. 53 */ 54 #define IA64_GATHER_BUNDLE 8 55 56 struct mmu_gather { 57 struct mm_struct *mm; 58 unsigned int nr; 59 unsigned int max; 60 unsigned char fullmm; /* non-zero means full mm flush */ 61 unsigned char need_flush; /* really unmapped some PTEs? */ 62 unsigned long start, end; 63 unsigned long start_addr; 64 unsigned long end_addr; 65 struct page **pages; 66 struct page *local[IA64_GATHER_BUNDLE]; 67 }; 68 69 struct ia64_tr_entry { 70 u64 ifa; 71 u64 itir; 72 u64 pte; 73 u64 rr; 74 }; /*Record for tr entry!*/ 75 76 extern int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size); 77 extern void ia64_ptr_entry(u64 target_mask, int slot); 78 79 extern struct ia64_tr_entry *ia64_idtrs[NR_CPUS]; 80 81 /* 82 region register macros 83 */ 84 #define RR_TO_VE(val) (((val) >> 0) & 0x0000000000000001) 85 #define RR_VE(val) (((val) & 0x0000000000000001) << 0) 86 #define RR_VE_MASK 0x0000000000000001L 87 #define RR_VE_SHIFT 0 88 #define RR_TO_PS(val) (((val) >> 2) & 0x000000000000003f) 89 #define RR_PS(val) (((val) & 0x000000000000003f) << 2) 90 #define RR_PS_MASK 0x00000000000000fcL 91 #define RR_PS_SHIFT 2 92 #define RR_RID_MASK 0x00000000ffffff00L 93 #define RR_TO_RID(val) ((val >> 8) & 0xffffff) 94 95 static inline void 96 ia64_tlb_flush_mmu_tlbonly(struct mmu_gather *tlb, unsigned long start, unsigned long end) 97 { 98 tlb->need_flush = 0; 99 100 if (tlb->fullmm) { 101 /* 102 * Tearing down the entire address space. This happens both as a result 103 * of exit() and execve(). The latter case necessitates the call to 104 * flush_tlb_mm() here. 105 */ 106 flush_tlb_mm(tlb->mm); 107 } else if (unlikely (end - start >= 1024*1024*1024*1024UL 108 || REGION_NUMBER(start) != REGION_NUMBER(end - 1))) 109 { 110 /* 111 * If we flush more than a tera-byte or across regions, we're probably 112 * better off just flushing the entire TLB(s). This should be very rare 113 * and is not worth optimizing for. 114 */ 115 flush_tlb_all(); 116 } else { 117 /* 118 * flush_tlb_range() takes a vma instead of a mm pointer because 119 * some architectures want the vm_flags for ITLB/DTLB flush. 120 */ 121 struct vm_area_struct vma = TLB_FLUSH_VMA(tlb->mm, 0); 122 123 /* flush the address range from the tlb: */ 124 flush_tlb_range(&vma, start, end); 125 /* now flush the virt. page-table area mapping the address range: */ 126 flush_tlb_range(&vma, ia64_thash(start), ia64_thash(end)); 127 } 128 129 } 130 131 static inline void 132 ia64_tlb_flush_mmu_free(struct mmu_gather *tlb) 133 { 134 unsigned long i; 135 unsigned int nr; 136 137 /* lastly, release the freed pages */ 138 nr = tlb->nr; 139 140 tlb->nr = 0; 141 tlb->start_addr = ~0UL; 142 for (i = 0; i < nr; ++i) 143 free_page_and_swap_cache(tlb->pages[i]); 144 } 145 146 /* 147 * Flush the TLB for address range START to END and, if not in fast mode, release the 148 * freed pages that where gathered up to this point. 149 */ 150 static inline void 151 ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end) 152 { 153 if (!tlb->need_flush) 154 return; 155 ia64_tlb_flush_mmu_tlbonly(tlb, start, end); 156 ia64_tlb_flush_mmu_free(tlb); 157 } 158 159 static inline void __tlb_alloc_page(struct mmu_gather *tlb) 160 { 161 unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); 162 163 if (addr) { 164 tlb->pages = (void *)addr; 165 tlb->max = PAGE_SIZE / sizeof(void *); 166 } 167 } 168 169 170 static inline void 171 arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, 172 unsigned long start, unsigned long end) 173 { 174 tlb->mm = mm; 175 tlb->max = ARRAY_SIZE(tlb->local); 176 tlb->pages = tlb->local; 177 tlb->nr = 0; 178 tlb->fullmm = !(start | (end+1)); 179 tlb->start = start; 180 tlb->end = end; 181 tlb->start_addr = ~0UL; 182 } 183 184 /* 185 * Called at the end of the shootdown operation to free up any resources that were 186 * collected. 187 */ 188 static inline void 189 arch_tlb_finish_mmu(struct mmu_gather *tlb, 190 unsigned long start, unsigned long end, bool force) 191 { 192 if (force) 193 tlb->need_flush = 1; 194 /* 195 * Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and 196 * tlb->end_addr. 197 */ 198 ia64_tlb_flush_mmu(tlb, start, end); 199 200 /* keep the page table cache within bounds */ 201 check_pgt_cache(); 202 203 if (tlb->pages != tlb->local) 204 free_pages((unsigned long)tlb->pages, 0); 205 } 206 207 /* 208 * Logically, this routine frees PAGE. On MP machines, the actual freeing of the page 209 * must be delayed until after the TLB has been flushed (see comments at the beginning of 210 * this file). 211 */ 212 static inline bool __tlb_remove_page(struct mmu_gather *tlb, struct page *page) 213 { 214 tlb->need_flush = 1; 215 216 if (!tlb->nr && tlb->pages == tlb->local) 217 __tlb_alloc_page(tlb); 218 219 tlb->pages[tlb->nr++] = page; 220 VM_WARN_ON(tlb->nr > tlb->max); 221 if (tlb->nr == tlb->max) 222 return true; 223 return false; 224 } 225 226 static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) 227 { 228 ia64_tlb_flush_mmu_tlbonly(tlb, tlb->start_addr, tlb->end_addr); 229 } 230 231 static inline void tlb_flush_mmu_free(struct mmu_gather *tlb) 232 { 233 ia64_tlb_flush_mmu_free(tlb); 234 } 235 236 static inline void tlb_flush_mmu(struct mmu_gather *tlb) 237 { 238 ia64_tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr); 239 } 240 241 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) 242 { 243 if (__tlb_remove_page(tlb, page)) 244 tlb_flush_mmu(tlb); 245 } 246 247 static inline bool __tlb_remove_page_size(struct mmu_gather *tlb, 248 struct page *page, int page_size) 249 { 250 return __tlb_remove_page(tlb, page); 251 } 252 253 static inline void tlb_remove_page_size(struct mmu_gather *tlb, 254 struct page *page, int page_size) 255 { 256 return tlb_remove_page(tlb, page); 257 } 258 259 /* 260 * Remove TLB entry for PTE mapped at virtual address ADDRESS. This is called for any 261 * PTE, not just those pointing to (normal) physical memory. 262 */ 263 static inline void 264 __tlb_remove_tlb_entry (struct mmu_gather *tlb, pte_t *ptep, unsigned long address) 265 { 266 if (tlb->start_addr == ~0UL) 267 tlb->start_addr = address; 268 tlb->end_addr = address + PAGE_SIZE; 269 } 270 271 #define tlb_migrate_finish(mm) platform_tlb_migrate_finish(mm) 272 273 #define tlb_start_vma(tlb, vma) do { } while (0) 274 #define tlb_end_vma(tlb, vma) do { } while (0) 275 276 #define tlb_remove_tlb_entry(tlb, ptep, addr) \ 277 do { \ 278 tlb->need_flush = 1; \ 279 __tlb_remove_tlb_entry(tlb, ptep, addr); \ 280 } while (0) 281 282 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \ 283 tlb_remove_tlb_entry(tlb, ptep, address) 284 285 #define tlb_remove_check_page_size_change tlb_remove_check_page_size_change 286 static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, 287 unsigned int page_size) 288 { 289 } 290 291 #define pte_free_tlb(tlb, ptep, address) \ 292 do { \ 293 tlb->need_flush = 1; \ 294 __pte_free_tlb(tlb, ptep, address); \ 295 } while (0) 296 297 #define pmd_free_tlb(tlb, ptep, address) \ 298 do { \ 299 tlb->need_flush = 1; \ 300 __pmd_free_tlb(tlb, ptep, address); \ 301 } while (0) 302 303 #define pud_free_tlb(tlb, pudp, address) \ 304 do { \ 305 tlb->need_flush = 1; \ 306 __pud_free_tlb(tlb, pudp, address); \ 307 } while (0) 308 309 #endif /* _ASM_IA64_TLB_H */ 310