1 /* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (C) 1994 - 2002 by Ralf Baechle 7 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc. 8 * Copyright (C) 2002 Maciej W. Rozycki 9 */ 10 #ifndef _ASM_PGTABLE_BITS_H 11 #define _ASM_PGTABLE_BITS_H 12 13 14 /* 15 * Note that we shift the lower 32bits of each EntryLo[01] entry 16 * 6 bits to the left. That way we can convert the PFN into the 17 * physical address by a single 'and' operation and gain 6 additional 18 * bits for storing information which isn't present in a normal 19 * MIPS page table. 20 * 21 * Similar to the Alpha port, we need to keep track of the ref 22 * and mod bits in software. We have a software "yeah you can read 23 * from this page" bit, and a hardware one which actually lets the 24 * process read from the page. On the same token we have a software 25 * writable bit and the real hardware one which actually lets the 26 * process write to the page, this keeps a mod bit via the hardware 27 * dirty bit. 28 * 29 * Certain revisions of the R4000 and R5000 have a bug where if a 30 * certain sequence occurs in the last 3 instructions of an executable 31 * page, and the following page is not mapped, the cpu can do 32 * unpredictable things. The code (when it is written) to deal with 33 * this problem will be in the update_mmu_cache() code for the r4k. 34 */ 35 #if defined(CONFIG_XPA) 36 37 /* 38 * Page table bit offsets used for 64 bit physical addressing on 39 * MIPS32r5 with XPA. 40 */ 41 enum pgtable_bits { 42 /* Used by TLB hardware (placed in EntryLo*) */ 43 _PAGE_NO_EXEC_SHIFT, 44 _PAGE_NO_READ_SHIFT, 45 _PAGE_GLOBAL_SHIFT, 46 _PAGE_VALID_SHIFT, 47 _PAGE_DIRTY_SHIFT, 48 _CACHE_SHIFT, 49 50 /* Used only by software (masked out before writing EntryLo*) */ 51 _PAGE_PRESENT_SHIFT = 24, 52 _PAGE_WRITE_SHIFT, 53 _PAGE_ACCESSED_SHIFT, 54 _PAGE_MODIFIED_SHIFT, 55 #if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) 56 _PAGE_SPECIAL_SHIFT, 57 #endif 58 #if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY) 59 _PAGE_SOFT_DIRTY_SHIFT, 60 #endif 61 }; 62 63 /* 64 * Bits for extended EntryLo0/EntryLo1 registers 65 */ 66 #define _PFNX_MASK 0xffffff 67 68 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32) 69 70 /* 71 * Page table bit offsets used for 36 bit physical addressing on MIPS32, 72 * for example with Alchemy or Netlogic XLP/XLR. 73 */ 74 enum pgtable_bits { 75 /* Used by TLB hardware (placed in EntryLo*) */ 76 _PAGE_GLOBAL_SHIFT, 77 _PAGE_VALID_SHIFT, 78 _PAGE_DIRTY_SHIFT, 79 _CACHE_SHIFT, 80 81 /* Used only by software (masked out before writing EntryLo*) */ 82 _PAGE_PRESENT_SHIFT = _CACHE_SHIFT + 3, 83 _PAGE_NO_READ_SHIFT, 84 _PAGE_WRITE_SHIFT, 85 _PAGE_ACCESSED_SHIFT, 86 _PAGE_MODIFIED_SHIFT, 87 #if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) 88 _PAGE_SPECIAL_SHIFT, 89 #endif 90 #if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY) 91 _PAGE_SOFT_DIRTY_SHIFT, 92 #endif 93 }; 94 95 #elif defined(CONFIG_CPU_R3K_TLB) 96 97 /* Page table bits used for r3k systems */ 98 enum pgtable_bits { 99 /* Used only by software (writes to EntryLo ignored) */ 100 _PAGE_PRESENT_SHIFT, 101 _PAGE_NO_READ_SHIFT, 102 _PAGE_WRITE_SHIFT, 103 _PAGE_ACCESSED_SHIFT, 104 _PAGE_MODIFIED_SHIFT, 105 #if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) 106 _PAGE_SPECIAL_SHIFT, 107 #endif 108 #if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY) 109 _PAGE_SOFT_DIRTY_SHIFT, 110 #endif 111 112 /* Used by TLB hardware (placed in EntryLo) */ 113 _PAGE_GLOBAL_SHIFT = 8, 114 _PAGE_VALID_SHIFT, 115 _PAGE_DIRTY_SHIFT, 116 _CACHE_UNCACHED_SHIFT, 117 }; 118 119 #else 120 121 /* Page table bits used for r4k systems */ 122 enum pgtable_bits { 123 /* Used only by software (masked out before writing EntryLo*) */ 124 _PAGE_PRESENT_SHIFT, 125 #if !defined(CONFIG_CPU_HAS_RIXI) 126 _PAGE_NO_READ_SHIFT, 127 #endif 128 _PAGE_WRITE_SHIFT, 129 _PAGE_ACCESSED_SHIFT, 130 _PAGE_MODIFIED_SHIFT, 131 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) 132 _PAGE_HUGE_SHIFT, 133 #endif 134 #if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) 135 _PAGE_SPECIAL_SHIFT, 136 #endif 137 #if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY) 138 _PAGE_SOFT_DIRTY_SHIFT, 139 #endif 140 /* Used by TLB hardware (placed in EntryLo*) */ 141 #if defined(CONFIG_CPU_HAS_RIXI) 142 _PAGE_NO_EXEC_SHIFT, 143 _PAGE_NO_READ_SHIFT, 144 #endif 145 _PAGE_GLOBAL_SHIFT, 146 _PAGE_VALID_SHIFT, 147 _PAGE_DIRTY_SHIFT, 148 _CACHE_SHIFT, 149 }; 150 151 #endif /* defined(CONFIG_PHYS_ADDR_T_64BIT && defined(CONFIG_CPU_MIPS32) */ 152 153 /* Used only by software */ 154 #define _PAGE_PRESENT (1 << _PAGE_PRESENT_SHIFT) 155 #define _PAGE_WRITE (1 << _PAGE_WRITE_SHIFT) 156 #define _PAGE_ACCESSED (1 << _PAGE_ACCESSED_SHIFT) 157 #define _PAGE_MODIFIED (1 << _PAGE_MODIFIED_SHIFT) 158 #if defined(CONFIG_MIPS_HUGE_TLB_SUPPORT) 159 # define _PAGE_HUGE (1 << _PAGE_HUGE_SHIFT) 160 #endif 161 #if defined(CONFIG_ARCH_HAS_PTE_SPECIAL) 162 # define _PAGE_SPECIAL (1 << _PAGE_SPECIAL_SHIFT) 163 #else 164 # define _PAGE_SPECIAL 0 165 #endif 166 #if defined(CONFIG_HAVE_ARCH_SOFT_DIRTY) 167 # define _PAGE_SOFT_DIRTY (1 << _PAGE_SOFT_DIRTY_SHIFT) 168 #else 169 # define _PAGE_SOFT_DIRTY 0 170 #endif 171 172 /* Used by TLB hardware (placed in EntryLo*) */ 173 #if defined(CONFIG_XPA) 174 # define _PAGE_NO_EXEC (1 << _PAGE_NO_EXEC_SHIFT) 175 #elif defined(CONFIG_CPU_HAS_RIXI) 176 # define _PAGE_NO_EXEC (cpu_has_rixi ? (1 << _PAGE_NO_EXEC_SHIFT) : 0) 177 #endif 178 #define _PAGE_NO_READ (1 << _PAGE_NO_READ_SHIFT) 179 #define _PAGE_GLOBAL (1 << _PAGE_GLOBAL_SHIFT) 180 #define _PAGE_VALID (1 << _PAGE_VALID_SHIFT) 181 #define _PAGE_DIRTY (1 << _PAGE_DIRTY_SHIFT) 182 #if defined(CONFIG_CPU_R3K_TLB) 183 # define _CACHE_UNCACHED (1 << _CACHE_UNCACHED_SHIFT) 184 # define _CACHE_MASK _CACHE_UNCACHED 185 # define PFN_PTE_SHIFT PAGE_SHIFT 186 #else 187 # define _CACHE_MASK (7 << _CACHE_SHIFT) 188 # define PFN_PTE_SHIFT (PAGE_SHIFT - 12 + _CACHE_SHIFT + 3) 189 #endif 190 191 #ifndef _PAGE_NO_EXEC 192 #define _PAGE_NO_EXEC 0 193 #endif 194 195 #define _PAGE_SILENT_READ _PAGE_VALID 196 #define _PAGE_SILENT_WRITE _PAGE_DIRTY 197 198 #define _PFN_MASK (~((1 << (PFN_PTE_SHIFT)) - 1)) 199 200 /* 201 * The final layouts of the PTE bits are: 202 * 203 * 64-bit, R1 or earlier: CCC D V G [S H] M A W R P 204 * 32-bit, R1 or earlier: CCC D V G M A W R P 205 * 64-bit, R2 or later: CCC D V G RI/R XI [S H] M A W P 206 * 32-bit, R2 or later: CCC D V G RI/R XI M A W P 207 */ 208 209 210 /* 211 * pte_to_entrylo converts a page table entry (PTE) into a Mips 212 * entrylo0/1 value. 213 */ 214 static inline uint64_t pte_to_entrylo(unsigned long pte_val) 215 { 216 #ifdef CONFIG_CPU_HAS_RIXI 217 if (cpu_has_rixi) { 218 int sa; 219 #ifdef CONFIG_32BIT 220 sa = 31 - _PAGE_NO_READ_SHIFT; 221 #else 222 sa = 63 - _PAGE_NO_READ_SHIFT; 223 #endif 224 /* 225 * C has no way to express that this is a DSRL 226 * _PAGE_NO_EXEC_SHIFT followed by a ROTR 2. Luckily 227 * in the fast path this is done in assembly 228 */ 229 return (pte_val >> _PAGE_GLOBAL_SHIFT) | 230 ((pte_val & (_PAGE_NO_EXEC | _PAGE_NO_READ)) << sa); 231 } 232 #endif 233 234 return pte_val >> _PAGE_GLOBAL_SHIFT; 235 } 236 237 /* 238 * Cache attributes 239 */ 240 #if defined(CONFIG_CPU_R3K_TLB) 241 242 #define _CACHE_CACHABLE_NONCOHERENT 0 243 #define _CACHE_UNCACHED_ACCELERATED _CACHE_UNCACHED 244 245 #elif defined(CONFIG_CPU_SB1) 246 247 /* No penalty for being coherent on the SB1, so just 248 use it for "noncoherent" spaces, too. Shouldn't hurt. */ 249 250 #define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT) 251 252 #endif 253 254 #ifndef _CACHE_CACHABLE_NO_WA 255 #define _CACHE_CACHABLE_NO_WA (0<<_CACHE_SHIFT) 256 #endif 257 #ifndef _CACHE_CACHABLE_WA 258 #define _CACHE_CACHABLE_WA (1<<_CACHE_SHIFT) 259 #endif 260 #ifndef _CACHE_UNCACHED 261 #define _CACHE_UNCACHED (2<<_CACHE_SHIFT) 262 #endif 263 #ifndef _CACHE_CACHABLE_NONCOHERENT 264 #define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT) 265 #endif 266 #ifndef _CACHE_CACHABLE_CE 267 #define _CACHE_CACHABLE_CE (4<<_CACHE_SHIFT) 268 #endif 269 #ifndef _CACHE_CACHABLE_COW 270 #define _CACHE_CACHABLE_COW (5<<_CACHE_SHIFT) 271 #endif 272 #ifndef _CACHE_CACHABLE_CUW 273 #define _CACHE_CACHABLE_CUW (6<<_CACHE_SHIFT) 274 #endif 275 #ifndef _CACHE_UNCACHED_ACCELERATED 276 #define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT) 277 #endif 278 279 #define __READABLE (_PAGE_SILENT_READ | _PAGE_ACCESSED) 280 #define __WRITEABLE (_PAGE_SILENT_WRITE | _PAGE_WRITE | _PAGE_MODIFIED) 281 282 #define _PAGE_CHG_MASK (_PAGE_ACCESSED | _PAGE_MODIFIED | \ 283 _PAGE_SOFT_DIRTY | _PFN_MASK | \ 284 _CACHE_MASK | _PAGE_SPECIAL) 285 286 #endif /* _ASM_PGTABLE_BITS_H */ 287