1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2012 Regents of the University of California 4 */ 5 6 #ifndef _ASM_RISCV_PGTABLE_H 7 #define _ASM_RISCV_PGTABLE_H 8 9 #include <linux/mmzone.h> 10 11 #include <asm/pgtable-bits.h> 12 13 #ifndef __ASSEMBLY__ 14 15 /* Page Upper Directory not used in RISC-V */ 16 #include <asm-generic/pgtable-nopud.h> 17 #include <asm/page.h> 18 #include <asm/tlbflush.h> 19 #include <linux/mm_types.h> 20 21 #ifdef CONFIG_64BIT 22 #include <asm/pgtable-64.h> 23 #else 24 #include <asm/pgtable-32.h> 25 #endif /* CONFIG_64BIT */ 26 27 /* Number of entries in the page global directory */ 28 #define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t)) 29 /* Number of entries in the page table */ 30 #define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t)) 31 32 /* Number of PGD entries that a user-mode program can use */ 33 #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) 34 #define FIRST_USER_ADDRESS 0 35 36 /* Page protection bits */ 37 #define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER) 38 39 #define PAGE_NONE __pgprot(_PAGE_PROT_NONE) 40 #define PAGE_READ __pgprot(_PAGE_BASE | _PAGE_READ) 41 #define PAGE_WRITE __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE) 42 #define PAGE_EXEC __pgprot(_PAGE_BASE | _PAGE_EXEC) 43 #define PAGE_READ_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC) 44 #define PAGE_WRITE_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | \ 45 _PAGE_EXEC | _PAGE_WRITE) 46 47 #define PAGE_COPY PAGE_READ 48 #define PAGE_COPY_EXEC PAGE_EXEC 49 #define PAGE_COPY_READ_EXEC PAGE_READ_EXEC 50 #define PAGE_SHARED PAGE_WRITE 51 #define PAGE_SHARED_EXEC PAGE_WRITE_EXEC 52 53 #define _PAGE_KERNEL (_PAGE_READ \ 54 | _PAGE_WRITE \ 55 | _PAGE_PRESENT \ 56 | _PAGE_ACCESSED \ 57 | _PAGE_DIRTY) 58 59 #define PAGE_KERNEL __pgprot(_PAGE_KERNEL) 60 #define PAGE_KERNEL_EXEC __pgprot(_PAGE_KERNEL | _PAGE_EXEC) 61 62 #define PAGE_TABLE __pgprot(_PAGE_TABLE) 63 64 extern pgd_t swapper_pg_dir[]; 65 66 /* MAP_PRIVATE permissions: xwr (copy-on-write) */ 67 #define __P000 PAGE_NONE 68 #define __P001 PAGE_READ 69 #define __P010 PAGE_COPY 70 #define __P011 PAGE_COPY 71 #define __P100 PAGE_EXEC 72 #define __P101 PAGE_READ_EXEC 73 #define __P110 PAGE_COPY_EXEC 74 #define __P111 PAGE_COPY_READ_EXEC 75 76 /* MAP_SHARED permissions: xwr */ 77 #define __S000 PAGE_NONE 78 #define __S001 PAGE_READ 79 #define __S010 PAGE_SHARED 80 #define __S011 PAGE_SHARED 81 #define __S100 PAGE_EXEC 82 #define __S101 PAGE_READ_EXEC 83 #define __S110 PAGE_SHARED_EXEC 84 #define __S111 PAGE_SHARED_EXEC 85 86 #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) 87 #define VMALLOC_END (PAGE_OFFSET - 1) 88 #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) 89 90 /* 91 * Roughly size the vmemmap space to be large enough to fit enough 92 * struct pages to map half the virtual address space. Then 93 * position vmemmap directly below the VMALLOC region. 94 */ 95 #define VMEMMAP_SHIFT \ 96 (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) 97 #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) 98 #define VMEMMAP_END (VMALLOC_START - 1) 99 #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) 100 101 #define vmemmap ((struct page *)VMEMMAP_START) 102 103 #define FIXADDR_TOP (VMEMMAP_START) 104 #ifdef CONFIG_64BIT 105 #define FIXADDR_SIZE PMD_SIZE 106 #else 107 #define FIXADDR_SIZE PGDIR_SIZE 108 #endif 109 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) 110 111 /* 112 * ZERO_PAGE is a global shared page that is always zero, 113 * used for zero-mapped memory areas, etc. 114 */ 115 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; 116 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) 117 118 static inline int pmd_present(pmd_t pmd) 119 { 120 return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE)); 121 } 122 123 static inline int pmd_none(pmd_t pmd) 124 { 125 return (pmd_val(pmd) == 0); 126 } 127 128 static inline int pmd_bad(pmd_t pmd) 129 { 130 return !pmd_present(pmd); 131 } 132 133 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) 134 { 135 *pmdp = pmd; 136 } 137 138 static inline void pmd_clear(pmd_t *pmdp) 139 { 140 set_pmd(pmdp, __pmd(0)); 141 } 142 143 static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot) 144 { 145 return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); 146 } 147 148 static inline unsigned long _pgd_pfn(pgd_t pgd) 149 { 150 return pgd_val(pgd) >> _PAGE_PFN_SHIFT; 151 } 152 153 #define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) 154 155 /* Locate an entry in the page global directory */ 156 static inline pgd_t *pgd_offset(const struct mm_struct *mm, unsigned long addr) 157 { 158 return mm->pgd + pgd_index(addr); 159 } 160 /* Locate an entry in the kernel page global directory */ 161 #define pgd_offset_k(addr) pgd_offset(&init_mm, (addr)) 162 163 static inline struct page *pmd_page(pmd_t pmd) 164 { 165 return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT); 166 } 167 168 static inline unsigned long pmd_page_vaddr(pmd_t pmd) 169 { 170 return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT); 171 } 172 173 /* Yields the page frame number (PFN) of a page table entry */ 174 static inline unsigned long pte_pfn(pte_t pte) 175 { 176 return (pte_val(pte) >> _PAGE_PFN_SHIFT); 177 } 178 179 #define pte_page(x) pfn_to_page(pte_pfn(x)) 180 181 /* Constructs a page table entry */ 182 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot) 183 { 184 return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot)); 185 } 186 187 #define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot) 188 189 #define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) 190 191 static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long addr) 192 { 193 return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(addr); 194 } 195 196 #define pte_offset_map(dir, addr) pte_offset_kernel((dir), (addr)) 197 #define pte_unmap(pte) ((void)(pte)) 198 199 static inline int pte_present(pte_t pte) 200 { 201 return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)); 202 } 203 204 static inline int pte_none(pte_t pte) 205 { 206 return (pte_val(pte) == 0); 207 } 208 209 static inline int pte_write(pte_t pte) 210 { 211 return pte_val(pte) & _PAGE_WRITE; 212 } 213 214 static inline int pte_exec(pte_t pte) 215 { 216 return pte_val(pte) & _PAGE_EXEC; 217 } 218 219 static inline int pte_huge(pte_t pte) 220 { 221 return pte_present(pte) 222 && (pte_val(pte) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC)); 223 } 224 225 static inline int pte_dirty(pte_t pte) 226 { 227 return pte_val(pte) & _PAGE_DIRTY; 228 } 229 230 static inline int pte_young(pte_t pte) 231 { 232 return pte_val(pte) & _PAGE_ACCESSED; 233 } 234 235 static inline int pte_special(pte_t pte) 236 { 237 return pte_val(pte) & _PAGE_SPECIAL; 238 } 239 240 /* static inline pte_t pte_rdprotect(pte_t pte) */ 241 242 static inline pte_t pte_wrprotect(pte_t pte) 243 { 244 return __pte(pte_val(pte) & ~(_PAGE_WRITE)); 245 } 246 247 /* static inline pte_t pte_mkread(pte_t pte) */ 248 249 static inline pte_t pte_mkwrite(pte_t pte) 250 { 251 return __pte(pte_val(pte) | _PAGE_WRITE); 252 } 253 254 /* static inline pte_t pte_mkexec(pte_t pte) */ 255 256 static inline pte_t pte_mkdirty(pte_t pte) 257 { 258 return __pte(pte_val(pte) | _PAGE_DIRTY); 259 } 260 261 static inline pte_t pte_mkclean(pte_t pte) 262 { 263 return __pte(pte_val(pte) & ~(_PAGE_DIRTY)); 264 } 265 266 static inline pte_t pte_mkyoung(pte_t pte) 267 { 268 return __pte(pte_val(pte) | _PAGE_ACCESSED); 269 } 270 271 static inline pte_t pte_mkold(pte_t pte) 272 { 273 return __pte(pte_val(pte) & ~(_PAGE_ACCESSED)); 274 } 275 276 static inline pte_t pte_mkspecial(pte_t pte) 277 { 278 return __pte(pte_val(pte) | _PAGE_SPECIAL); 279 } 280 281 static inline pte_t pte_mkhuge(pte_t pte) 282 { 283 return pte; 284 } 285 286 /* Modify page protection bits */ 287 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 288 { 289 return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); 290 } 291 292 #define pgd_ERROR(e) \ 293 pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e)) 294 295 296 /* Commit new configuration to MMU hardware */ 297 static inline void update_mmu_cache(struct vm_area_struct *vma, 298 unsigned long address, pte_t *ptep) 299 { 300 /* 301 * The kernel assumes that TLBs don't cache invalid entries, but 302 * in RISC-V, SFENCE.VMA specifies an ordering constraint, not a 303 * cache flush; it is necessary even after writing invalid entries. 304 * Relying on flush_tlb_fix_spurious_fault would suffice, but 305 * the extra traps reduce performance. So, eagerly SFENCE.VMA. 306 */ 307 local_flush_tlb_page(address); 308 } 309 310 #define __HAVE_ARCH_PTE_SAME 311 static inline int pte_same(pte_t pte_a, pte_t pte_b) 312 { 313 return pte_val(pte_a) == pte_val(pte_b); 314 } 315 316 /* 317 * Certain architectures need to do special things when PTEs within 318 * a page table are directly modified. Thus, the following hook is 319 * made available. 320 */ 321 static inline void set_pte(pte_t *ptep, pte_t pteval) 322 { 323 *ptep = pteval; 324 } 325 326 void flush_icache_pte(pte_t pte); 327 328 static inline void set_pte_at(struct mm_struct *mm, 329 unsigned long addr, pte_t *ptep, pte_t pteval) 330 { 331 if (pte_present(pteval) && pte_exec(pteval)) 332 flush_icache_pte(pteval); 333 334 set_pte(ptep, pteval); 335 } 336 337 static inline void pte_clear(struct mm_struct *mm, 338 unsigned long addr, pte_t *ptep) 339 { 340 set_pte_at(mm, addr, ptep, __pte(0)); 341 } 342 343 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS 344 static inline int ptep_set_access_flags(struct vm_area_struct *vma, 345 unsigned long address, pte_t *ptep, 346 pte_t entry, int dirty) 347 { 348 if (!pte_same(*ptep, entry)) 349 set_pte_at(vma->vm_mm, address, ptep, entry); 350 /* 351 * update_mmu_cache will unconditionally execute, handling both 352 * the case that the PTE changed and the spurious fault case. 353 */ 354 return true; 355 } 356 357 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR 358 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, 359 unsigned long address, pte_t *ptep) 360 { 361 return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0)); 362 } 363 364 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG 365 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, 366 unsigned long address, 367 pte_t *ptep) 368 { 369 if (!pte_young(*ptep)) 370 return 0; 371 return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep)); 372 } 373 374 #define __HAVE_ARCH_PTEP_SET_WRPROTECT 375 static inline void ptep_set_wrprotect(struct mm_struct *mm, 376 unsigned long address, pte_t *ptep) 377 { 378 atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep); 379 } 380 381 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH 382 static inline int ptep_clear_flush_young(struct vm_area_struct *vma, 383 unsigned long address, pte_t *ptep) 384 { 385 /* 386 * This comment is borrowed from x86, but applies equally to RISC-V: 387 * 388 * Clearing the accessed bit without a TLB flush 389 * doesn't cause data corruption. [ It could cause incorrect 390 * page aging and the (mistaken) reclaim of hot pages, but the 391 * chance of that should be relatively low. ] 392 * 393 * So as a performance optimization don't flush the TLB when 394 * clearing the accessed bit, it will eventually be flushed by 395 * a context switch or a VM operation anyway. [ In the rare 396 * event of it not getting flushed for a long time the delay 397 * shouldn't really matter because there's no real memory 398 * pressure for swapout to react to. ] 399 */ 400 return ptep_test_and_clear_young(vma, address, ptep); 401 } 402 403 /* 404 * Encode and decode a swap entry 405 * 406 * Format of swap PTE: 407 * bit 0: _PAGE_PRESENT (zero) 408 * bit 1: _PAGE_PROT_NONE (zero) 409 * bits 2 to 6: swap type 410 * bits 7 to XLEN-1: swap offset 411 */ 412 #define __SWP_TYPE_SHIFT 2 413 #define __SWP_TYPE_BITS 5 414 #define __SWP_TYPE_MASK ((1UL << __SWP_TYPE_BITS) - 1) 415 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) 416 417 #define MAX_SWAPFILES_CHECK() \ 418 BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 419 420 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) 421 #define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT) 422 #define __swp_entry(type, offset) ((swp_entry_t) \ 423 { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) 424 425 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 426 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 427 428 #define kern_addr_valid(addr) (1) /* FIXME */ 429 430 extern void *dtb_early_va; 431 extern void setup_bootmem(void); 432 extern void paging_init(void); 433 434 /* 435 * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32. 436 * Note that PGDIR_SIZE must evenly divide TASK_SIZE. 437 */ 438 #ifdef CONFIG_64BIT 439 #define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2) 440 #else 441 #define TASK_SIZE FIXADDR_START 442 #endif 443 444 #include <asm-generic/pgtable.h> 445 446 #endif /* !__ASSEMBLY__ */ 447 448 #endif /* _ASM_RISCV_PGTABLE_H */ 449