1 /* $NetBSD: pte.h,v 1.15 2025/10/12 04:08:26 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2014, 2019, 2021 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matt Thomas (of 3am Software Foundry), Maxime Villard, and 9 * Nick Hudson. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #ifndef _RISCV_PTE_H_ 34 #define _RISCV_PTE_H_ 35 36 #ifdef _LP64 /* Sv39 */ 37 #define PTE_PPN __BITS(53, 10) 38 #define PTE_PPN0 __BITS(18, 10) 39 #define PTE_PPN1 __BITS(27, 19) 40 #define PTE_PPN2 __BITS(53, 28) 41 typedef uint64_t pt_entry_t; 42 typedef uint64_t pd_entry_t; 43 #define atomic_cas_pte atomic_cas_64 44 #else /* Sv32 */ 45 #define PTE_PPN __BITS(31, 10) 46 #define PTE_PPN0 __BITS(19, 10) 47 #define PTE_PPN1 __BITS(31, 20) 48 typedef uint32_t pt_entry_t; 49 typedef uint32_t pd_entry_t; 50 #define atomic_cas_pte atomic_cas_32 51 #endif 52 53 #define PTE_PPN_SHIFT 10 54 55 #define NPTEPG (NBPG / sizeof(pt_entry_t)) 56 #define NSEGPG NPTEPG 57 #define NPDEPG NPTEPG 58 59 60 /* HardWare PTE bits SV39 */ 61 #define PTE_N __BIT(63) // Svnapot 62 #define PTE_PBMT __BITS(62, 61) // Svpbmt 63 #define PTE_reserved0 __BITS(60, 54) // 64 65 /* 66 * Svpbmt (Page Based Memory Types) extension: 67 * 68 * PMA --> adhere to physical memory attributes 69 * NC --> non-cacheable, idempotent, weakly-ordered 70 * IO --> non-cacheable, non-idempotent, strongly-ordered 71 */ 72 #define PTE_PBMT_PMA __SHIFTIN(0, PTE_PBMT) 73 #define PTE_PBMT_NC __SHIFTIN(1, PTE_PBMT) 74 #define PTE_PBMT_IO __SHIFTIN(2, PTE_PBMT) 75 76 /* XTheadMae (Memory Attribute Extensions) */ 77 #define PTE_XMAE __BITS(63,59) 78 #define PTE_XMAE_SO __BIT(63) // Strong Order 79 #define PTE_XMAE_C __BIT(62) // Cacheable 80 #define PTE_XMAE_B __BIT(61) // Bufferable 81 #define PTE_XMAE_SH __BIT(60) // Shareable 82 #define PTE_XMAE_T __BIT(59) // Trustable 83 84 /* 85 * Map to the rough PBMT equivalent: 86 * 87 * PMA (i.e. no specific attribute) --> C B SH 88 * NC --> B SH 89 * IO --> SO SH 90 */ 91 #define PTE_XMAE_PMA ( PTE_XMAE_C | PTE_XMAE_B | PTE_XMAE_SH) 92 #define PTE_XMAE_NC ( PTE_XMAE_B | PTE_XMAE_SH) 93 #define PTE_XMAE_IO (PTE_XMAE_SO | PTE_XMAE_SH) 94 95 /* Software PTE bits. */ 96 #define PTE_RSW __BITS(9, 8) 97 #define PTE_WIRED __BIT(9) 98 99 /* Hardware PTE bits. */ 100 // These are hardware defined bits 101 #define PTE_D __BIT(7) // Dirty 102 #define PTE_A __BIT(6) // Accessed 103 #define PTE_G __BIT(5) // Global 104 #define PTE_U __BIT(4) // User 105 #define PTE_X __BIT(3) // eXecute 106 #define PTE_W __BIT(2) // Write 107 #define PTE_R __BIT(1) // Read 108 #define PTE_V __BIT(0) // Valid 109 110 #define PTE_HARDWIRED (PTE_A | PTE_D) 111 #define PTE_USER (PTE_V | PTE_U) 112 #define PTE_KERN (PTE_V | PTE_G) 113 #define PTE_RW (PTE_R | PTE_W) 114 #define PTE_RX (PTE_R | PTE_X) 115 #define PTE_RWX (PTE_R | PTE_W | PTE_X) 116 117 #define PTE_ISLEAF_P(pte) (((pte) & PTE_RWX) != 0) 118 119 #define PA_TO_PTE(pa) (((pa) >> PGSHIFT) << PTE_PPN_SHIFT) 120 #define PTE_TO_PA(pte) (__SHIFTOUT((pte), PTE_PPN) << PGSHIFT) 121 122 #if defined(_KERNEL) 123 124 static inline bool 125 pte_valid_p(pt_entry_t pte) 126 { 127 return (pte & PTE_V) != 0; 128 } 129 130 static inline bool 131 pte_wired_p(pt_entry_t pte) 132 { 133 return (pte & PTE_WIRED) != 0; 134 } 135 136 static inline bool 137 pte_modified_p(pt_entry_t pte) 138 { 139 return (pte & PTE_D) != 0; 140 } 141 142 static inline bool 143 pte_cached_p(pt_entry_t pte) 144 { 145 /* TODO: This seems wrong... */ 146 return true; 147 } 148 149 static inline bool 150 pte_deferred_exec_p(pt_entry_t pte) 151 { 152 return false; 153 } 154 155 static inline pt_entry_t 156 pte_wire_entry(pt_entry_t pte) 157 { 158 return pte | PTE_HARDWIRED | PTE_WIRED; 159 } 160 161 static inline pt_entry_t 162 pte_unwire_entry(pt_entry_t pte) 163 { 164 return pte & ~(PTE_HARDWIRED | PTE_WIRED); 165 } 166 167 static inline paddr_t 168 pte_to_paddr(pt_entry_t pte) 169 { 170 return PTE_TO_PA(pte); 171 } 172 173 static inline pt_entry_t 174 pte_nv_entry(bool kernel_p) 175 { 176 return 0; 177 } 178 179 static inline pt_entry_t 180 pte_prot_nowrite(pt_entry_t pte) 181 { 182 return pte & ~PTE_W; 183 } 184 185 static inline pt_entry_t 186 pte_prot_downgrade(pt_entry_t pte, vm_prot_t newprot) 187 { 188 if ((newprot & VM_PROT_READ) == 0) 189 pte &= ~PTE_R; 190 if ((newprot & VM_PROT_WRITE) == 0) 191 pte &= ~PTE_W; 192 if ((newprot & VM_PROT_EXECUTE) == 0) 193 pte &= ~PTE_X; 194 return pte; 195 } 196 197 static inline pt_entry_t 198 pte_prot_bits(struct vm_page_md *mdpg, vm_prot_t prot, bool kernel_p) 199 { 200 KASSERT(prot & VM_PROT_READ); 201 pt_entry_t pte = PTE_R; 202 203 if (prot & VM_PROT_EXECUTE) { 204 pte |= PTE_X; 205 } 206 if (prot & VM_PROT_WRITE) { 207 pte |= PTE_W; 208 } 209 210 return pte; 211 } 212 213 static inline pt_entry_t 214 pte_flag_bits(struct vm_page_md *mdpg, int flags, bool kernel_p) 215 { 216 return 0; 217 } 218 219 pt_entry_t pte_enter_flags_to_pbmt(int); 220 221 static inline pt_entry_t 222 pte_make_enter(paddr_t pa, struct vm_page_md *mdpg, vm_prot_t prot, 223 int flags, bool kernel_p) 224 { 225 pt_entry_t pte = (pt_entry_t)PA_TO_PTE(pa); 226 227 pte |= kernel_p ? PTE_KERN : PTE_USER; 228 pte |= pte_flag_bits(mdpg, flags, kernel_p); 229 pte |= pte_prot_bits(mdpg, prot, kernel_p); 230 pte |= pte_enter_flags_to_pbmt(flags); 231 232 if (mdpg != NULL) { 233 234 if ((prot & VM_PROT_WRITE) != 0 && 235 ((flags & VM_PROT_WRITE) != 0 || VM_PAGEMD_MODIFIED_P(mdpg))) { 236 /* 237 * This is a writable mapping, and the page's mod state 238 * indicates it has already been modified. No need for 239 * modified emulation. 240 */ 241 pte |= PTE_A; 242 } else if ((flags & VM_PROT_ALL) || VM_PAGEMD_REFERENCED_P(mdpg)) { 243 /* 244 * - The access type indicates that we don't need to do 245 * referenced emulation. 246 * OR 247 * - The physical page has already been referenced so no need 248 * to re-do referenced emulation here. 249 */ 250 pte |= PTE_A; 251 } 252 } else { 253 pte |= PTE_A | PTE_D; 254 } 255 256 return pte; 257 } 258 259 static inline pt_entry_t 260 pte_make_kenter_pa(paddr_t pa, struct vm_page_md *mdpg, vm_prot_t prot, 261 int flags) 262 { 263 pt_entry_t pte = (pt_entry_t)PA_TO_PTE(pa); 264 265 pte |= PTE_KERN | PTE_HARDWIRED | PTE_WIRED; 266 pte |= pte_flag_bits(NULL, flags, true); 267 pte |= pte_prot_bits(NULL, prot, true); 268 pte |= pte_enter_flags_to_pbmt(flags); 269 270 return pte; 271 } 272 273 static inline void 274 pte_set(pt_entry_t *ptep, pt_entry_t pte) 275 { 276 *ptep = pte; 277 } 278 279 static inline pd_entry_t 280 pte_invalid_pde(void) 281 { 282 return 0; 283 } 284 285 static inline pd_entry_t 286 pte_pde_pdetab(paddr_t pa, bool kernel_p) 287 { 288 return PTE_V | PA_TO_PTE(pa); 289 } 290 291 static inline pd_entry_t 292 pte_pde_ptpage(paddr_t pa, bool kernel_p) 293 { 294 return PTE_V | PA_TO_PTE(pa); 295 } 296 297 static inline bool 298 pte_pde_valid_p(pd_entry_t pde) 299 { 300 return (pde & (PTE_X | PTE_W | PTE_R | PTE_V)) == PTE_V; 301 } 302 303 static inline paddr_t 304 pte_pde_to_paddr(pd_entry_t pde) 305 { 306 return pte_to_paddr((pt_entry_t)pde); 307 } 308 309 static inline pd_entry_t 310 pte_pde_cas(pd_entry_t *pdep, pd_entry_t opde, pt_entry_t npde) 311 { 312 #ifdef MULTIPROCESSOR 313 #ifdef _LP64 314 return atomic_cas_64(pdep, opde, npde); 315 #else 316 return atomic_cas_32(pdep, opde, npde); 317 #endif 318 #else 319 *pdep = npde; 320 return 0; 321 #endif 322 } 323 324 static inline void 325 pte_pde_set(pd_entry_t *pdep, pd_entry_t npde) 326 { 327 328 *pdep = npde; 329 } 330 331 static inline pt_entry_t 332 pte_value(pt_entry_t pte) 333 { 334 return pte; 335 } 336 337 #endif /* _KERNEL */ 338 339 #endif /* _RISCV_PTE_H_ */ 340
Indexes created Sun Oct 12 05:10:08 GMT 2025