1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * OpenRISC Linux 4 * 5 * Linux architectural port borrowing liberally from similar works of 6 * others. All original copyrights apply as per the original source 7 * declaration. 8 * 9 * OpenRISC implementation: 10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 12 * et al. 13 */ 14 15 /* or1k pgtable.h - macros and functions to manipulate page tables 16 * 17 * Based on: 18 * include/asm-cris/pgtable.h 19 */ 20 21 #ifndef __ASM_OPENRISC_PGTABLE_H 22 #define __ASM_OPENRISC_PGTABLE_H 23 24 #include <asm-generic/pgtable-nopmd.h> 25 26 #ifndef __ASSEMBLY__ 27 #include <asm/mmu.h> 28 #include <asm/fixmap.h> 29 30 /* 31 * The Linux memory management assumes a three-level page table setup. On 32 * or1k, we use that, but "fold" the mid level into the top-level page 33 * table. Since the MMU TLB is software loaded through an interrupt, it 34 * supports any page table structure, so we could have used a three-level 35 * setup, but for the amounts of memory we normally use, a two-level is 36 * probably more efficient. 37 * 38 * This file contains the functions and defines necessary to modify and use 39 * the or1k page table tree. 40 */ 41 42 extern void paging_init(void); 43 44 /* Certain architectures need to do special things when pte's 45 * within a page table are directly modified. Thus, the following 46 * hook is made available. 47 */ 48 #define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) 49 #define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval) 50 /* 51 * (pmds are folded into pgds so this doesn't get actually called, 52 * but the define is needed for a generic inline function.) 53 */ 54 #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) 55 56 #define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2)) 57 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 58 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 59 60 /* 61 * entries per page directory level: we use a two-level, so 62 * we don't really have any PMD directory physically. 63 * pointers are 4 bytes so we can use the page size and 64 * divide it by 4 (shift by 2). 65 */ 66 #define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2)) 67 68 #define PTRS_PER_PGD (1UL << (32-PGDIR_SHIFT)) 69 70 /* calculate how many PGD entries a user-level program can use 71 * the first mappable virtual address is 0 72 * (TASK_SIZE is the maximum virtual address space) 73 */ 74 75 #define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) 76 77 /* 78 * Kernels own virtual memory area. 79 */ 80 81 /* 82 * The size and location of the vmalloc area are chosen so that modules 83 * placed in this area aren't more than a 28-bit signed offset from any 84 * kernel functions that they may need. This greatly simplifies handling 85 * of the relocations for l.j and l.jal instructions as we don't need to 86 * introduce any trampolines for reaching "distant" code. 87 * 88 * 64 MB of vmalloc area is comparable to what's available on other arches. 89 */ 90 91 #define VMALLOC_START (PAGE_OFFSET-0x04000000UL) 92 #define VMALLOC_END (PAGE_OFFSET) 93 #define VMALLOC_VMADDR(x) ((unsigned long)(x)) 94 95 /* Define some higher level generic page attributes. 96 * 97 * If you change _PAGE_CI definition be sure to change it in 98 * io.h for ioremap() too. 99 */ 100 101 /* 102 * An OR32 PTE looks like this: 103 * 104 * | 31 ... 10 | 9 | 8 ... 6 | 5 | 4 | 3 | 2 | 1 | 0 | 105 * Phys pg.num L PP Index D A WOM WBC CI CC 106 * 107 * L : link 108 * PPI: Page protection index 109 * D : Dirty 110 * A : Accessed 111 * WOM: Weakly ordered memory 112 * WBC: Write-back cache 113 * CI : Cache inhibit 114 * CC : Cache coherent 115 * 116 * The protection bits below should correspond to the layout of the actual 117 * PTE as per above 118 */ 119 120 #define _PAGE_CC 0x001 /* software: pte contains a translation */ 121 #define _PAGE_CI 0x002 /* cache inhibit */ 122 #define _PAGE_WBC 0x004 /* write back cache */ 123 #define _PAGE_WOM 0x008 /* weakly ordered memory */ 124 125 #define _PAGE_A 0x010 /* accessed */ 126 #define _PAGE_D 0x020 /* dirty */ 127 #define _PAGE_URE 0x040 /* user read enable */ 128 #define _PAGE_UWE 0x080 /* user write enable */ 129 130 #define _PAGE_SRE 0x100 /* superuser read enable */ 131 #define _PAGE_SWE 0x200 /* superuser write enable */ 132 #define _PAGE_EXEC 0x400 /* software: page is executable */ 133 #define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */ 134 135 /* 0x001 is cache coherency bit, which should always be set to 136 * 1 - for SMP (when we support it) 137 * 0 - otherwise 138 * 139 * we just reuse this bit in software for _PAGE_PRESENT and 140 * force it to 0 when loading it into TLB. 141 */ 142 #define _PAGE_PRESENT _PAGE_CC 143 #define _PAGE_USER _PAGE_URE 144 #define _PAGE_WRITE (_PAGE_UWE | _PAGE_SWE) 145 #define _PAGE_DIRTY _PAGE_D 146 #define _PAGE_ACCESSED _PAGE_A 147 #define _PAGE_NO_CACHE _PAGE_CI 148 #define _PAGE_SHARED _PAGE_U_SHARED 149 #define _PAGE_READ (_PAGE_URE | _PAGE_SRE) 150 151 #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) 152 #define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED) 153 #define _PAGE_ALL (_PAGE_PRESENT | _PAGE_ACCESSED) 154 #define _KERNPG_TABLE \ 155 (_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY) 156 157 /* We borrow bit 11 to store the exclusive marker in swap PTEs. */ 158 #define _PAGE_SWP_EXCLUSIVE _PAGE_U_SHARED 159 160 #define PAGE_NONE __pgprot(_PAGE_ALL) 161 #define PAGE_READONLY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) 162 #define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) 163 #define PAGE_SHARED \ 164 __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \ 165 | _PAGE_SHARED) 166 #define PAGE_SHARED_X \ 167 __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \ 168 | _PAGE_SHARED | _PAGE_EXEC) 169 #define PAGE_COPY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) 170 #define PAGE_COPY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) 171 172 #define PAGE_KERNEL \ 173 __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ 174 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC) 175 #define PAGE_KERNEL_RO \ 176 __pgprot(_PAGE_ALL | _PAGE_SRE \ 177 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC) 178 #define PAGE_KERNEL_NOCACHE \ 179 __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ 180 | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI) 181 182 /* zero page used for uninitialized stuff */ 183 extern unsigned long empty_zero_page[2048]; 184 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) 185 186 /* number of bits that fit into a memory pointer */ 187 #define BITS_PER_PTR (8*sizeof(unsigned long)) 188 189 /* to align the pointer to a pointer address */ 190 #define PTR_MASK (~(sizeof(void *)-1)) 191 192 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */ 193 /* 64-bit machines, beware! SRB. */ 194 #define SIZEOF_PTR_LOG2 2 195 196 /* to find an entry in a page-table */ 197 #define PAGE_PTR(address) \ 198 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) 199 200 /* to set the page-dir */ 201 #define SET_PAGE_DIR(tsk, pgdir) 202 203 #define pte_none(x) (!pte_val(x)) 204 #define pte_present(x) (pte_val(x) & _PAGE_PRESENT) 205 #define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0) 206 207 #define pmd_none(x) (!pmd_val(x)) 208 #define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK)) != _KERNPG_TABLE) 209 #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) 210 #define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) 211 212 /* 213 * The following only work if pte_present() is true. 214 * Undefined behaviour if not.. 215 */ 216 217 static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; } 218 static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } 219 static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; } 220 static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; } 221 static inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; } 222 223 static inline pte_t pte_wrprotect(pte_t pte) 224 { 225 pte_val(pte) &= ~(_PAGE_WRITE); 226 return pte; 227 } 228 229 static inline pte_t pte_rdprotect(pte_t pte) 230 { 231 pte_val(pte) &= ~(_PAGE_READ); 232 return pte; 233 } 234 235 static inline pte_t pte_exprotect(pte_t pte) 236 { 237 pte_val(pte) &= ~(_PAGE_EXEC); 238 return pte; 239 } 240 241 static inline pte_t pte_mkclean(pte_t pte) 242 { 243 pte_val(pte) &= ~(_PAGE_DIRTY); 244 return pte; 245 } 246 247 static inline pte_t pte_mkold(pte_t pte) 248 { 249 pte_val(pte) &= ~(_PAGE_ACCESSED); 250 return pte; 251 } 252 253 static inline pte_t pte_mkwrite(pte_t pte) 254 { 255 pte_val(pte) |= _PAGE_WRITE; 256 return pte; 257 } 258 259 static inline pte_t pte_mkread(pte_t pte) 260 { 261 pte_val(pte) |= _PAGE_READ; 262 return pte; 263 } 264 265 static inline pte_t pte_mkexec(pte_t pte) 266 { 267 pte_val(pte) |= _PAGE_EXEC; 268 return pte; 269 } 270 271 static inline pte_t pte_mkdirty(pte_t pte) 272 { 273 pte_val(pte) |= _PAGE_DIRTY; 274 return pte; 275 } 276 277 static inline pte_t pte_mkyoung(pte_t pte) 278 { 279 pte_val(pte) |= _PAGE_ACCESSED; 280 return pte; 281 } 282 283 /* 284 * Conversion functions: convert a page and protection to a page entry, 285 * and a page entry and page directory to the page they refer to. 286 */ 287 288 /* What actually goes as arguments to the various functions is less than 289 * obvious, but a rule of thumb is that struct page's goes as struct page *, 290 * really physical DRAM addresses are unsigned long's, and DRAM "virtual" 291 * addresses (the 0xc0xxxxxx's) goes as void *'s. 292 */ 293 294 static inline pte_t __mk_pte(void *page, pgprot_t pgprot) 295 { 296 pte_t pte; 297 /* the PTE needs a physical address */ 298 pte_val(pte) = __pa(page) | pgprot_val(pgprot); 299 return pte; 300 } 301 302 #define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot)) 303 304 #define mk_pte_phys(physpage, pgprot) \ 305 ({ \ 306 pte_t __pte; \ 307 \ 308 pte_val(__pte) = (physpage) + pgprot_val(pgprot); \ 309 __pte; \ 310 }) 311 312 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 313 { 314 pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); 315 return pte; 316 } 317 318 319 /* 320 * pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval 321 * __pte_page(pte_val) refers to the "virtual" DRAM interval 322 * pte_pagenr refers to the page-number counted starting from the virtual 323 * DRAM start 324 */ 325 326 static inline unsigned long __pte_page(pte_t pte) 327 { 328 /* the PTE contains a physical address */ 329 return (unsigned long)__va(pte_val(pte) & PAGE_MASK); 330 } 331 332 #define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT) 333 334 /* permanent address of a page */ 335 336 #define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT)) 337 #define pte_page(pte) (mem_map+pte_pagenr(pte)) 338 339 /* 340 * only the pte's themselves need to point to physical DRAM (see above) 341 * the pagetable links are purely handled within the kernel SW and thus 342 * don't need the __pa and __va transformations. 343 */ 344 static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) 345 { 346 pmd_val(*pmdp) = _KERNPG_TABLE | (unsigned long) ptep; 347 } 348 349 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT) 350 #define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)) 351 352 static inline unsigned long pmd_page_vaddr(pmd_t pmd) 353 { 354 return ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)); 355 } 356 357 #define __pmd_offset(address) \ 358 (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) 359 360 #define pte_pfn(x) ((unsigned long)(((x).pte)) >> PAGE_SHIFT) 361 #define pfn_pte(pfn, prot) __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot)) 362 363 #define pte_ERROR(e) \ 364 printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \ 365 __FILE__, __LINE__, &(e), pte_val(e)) 366 #define pgd_ERROR(e) \ 367 printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \ 368 __FILE__, __LINE__, &(e), pgd_val(e)) 369 370 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */ 371 372 struct vm_area_struct; 373 374 static inline void update_tlb(struct vm_area_struct *vma, 375 unsigned long address, pte_t *pte) 376 { 377 } 378 379 extern void update_cache(struct vm_area_struct *vma, 380 unsigned long address, pte_t *pte); 381 382 static inline void update_mmu_cache(struct vm_area_struct *vma, 383 unsigned long address, pte_t *pte) 384 { 385 update_tlb(vma, address, pte); 386 update_cache(vma, address, pte); 387 } 388 389 /* __PHX__ FIXME, SWAP, this probably doesn't work */ 390 391 /* 392 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that 393 * are !pte_none() && !pte_present(). 394 * 395 * Format of swap PTEs: 396 * 397 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 398 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 399 * <-------------- offset ---------------> E <- type --> 0 0 0 0 0 400 * 401 * E is the exclusive marker that is not stored in swap entries. 402 * The zero'ed bits include _PAGE_PRESENT. 403 */ 404 #define __swp_type(x) (((x).val >> 5) & 0x3f) 405 #define __swp_offset(x) ((x).val >> 12) 406 #define __swp_entry(type, offset) \ 407 ((swp_entry_t) { (((type) & 0x3f) << 5) | ((offset) << 12) }) 408 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 409 #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) 410 411 static inline int pte_swp_exclusive(pte_t pte) 412 { 413 return pte_val(pte) & _PAGE_SWP_EXCLUSIVE; 414 } 415 416 static inline pte_t pte_swp_mkexclusive(pte_t pte) 417 { 418 pte_val(pte) |= _PAGE_SWP_EXCLUSIVE; 419 return pte; 420 } 421 422 static inline pte_t pte_swp_clear_exclusive(pte_t pte) 423 { 424 pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE; 425 return pte; 426 } 427 428 typedef pte_t *pte_addr_t; 429 430 #endif /* __ASSEMBLY__ */ 431 #endif /* __ASM_OPENRISC_PGTABLE_H */ 432