1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * Based on arch/arm/mm/proc.S 4 * 5 * Copyright (C) 2001 Deep Blue Solutions Ltd. 6 * Copyright (C) 2012 ARM Ltd. 7 * Author: Catalin Marinas <catalin.marinas@arm.com> 8 */ 9 10#include <linux/init.h> 11#include <linux/linkage.h> 12#include <linux/pgtable.h> 13#include <linux/cfi_types.h> 14#include <asm/assembler.h> 15#include <asm/asm-offsets.h> 16#include <asm/asm_pointer_auth.h> 17#include <asm/hwcap.h> 18#include <asm/kernel-pgtable.h> 19#include <asm/pgtable-hwdef.h> 20#include <asm/cpufeature.h> 21#include <asm/alternative.h> 22#include <asm/smp.h> 23#include <asm/sysreg.h> 24 25#ifdef CONFIG_ARM64_64K_PAGES 26#define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K 27#elif defined(CONFIG_ARM64_16K_PAGES) 28#define TCR_TG_FLAGS TCR_TG0_16K | TCR_TG1_16K 29#else /* CONFIG_ARM64_4K_PAGES */ 30#define TCR_TG_FLAGS TCR_TG0_4K | TCR_TG1_4K 31#endif 32 33#ifdef CONFIG_RANDOMIZE_BASE 34#define TCR_KASLR_FLAGS TCR_NFD1 35#else 36#define TCR_KASLR_FLAGS 0 37#endif 38 39/* PTWs cacheable, inner/outer WBWA */ 40#define TCR_CACHE_FLAGS TCR_IRGN_WBWA | TCR_ORGN_WBWA 41 42#ifdef CONFIG_KASAN_SW_TAGS 43#define TCR_KASAN_SW_FLAGS TCR_TBI1 | TCR_TBID1 44#else 45#define TCR_KASAN_SW_FLAGS 0 46#endif 47 48#ifdef CONFIG_KASAN_HW_TAGS 49#define TCR_MTE_FLAGS TCR_TCMA1 | TCR_TBI1 | TCR_TBID1 50#elif defined(CONFIG_ARM64_MTE) 51/* 52 * The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on 53 * TBI being enabled at EL1. 54 */ 55#define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1 56#else 57#define TCR_MTE_FLAGS 0 58#endif 59 60/* 61 * Default MAIR_EL1. MT_NORMAL_TAGGED is initially mapped as Normal memory and 62 * changed during mte_cpu_setup to Normal Tagged if the system supports MTE. 63 */ 64#define MAIR_EL1_SET \ 65 (MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRnE, MT_DEVICE_nGnRnE) | \ 66 MAIR_ATTRIDX(MAIR_ATTR_DEVICE_nGnRE, MT_DEVICE_nGnRE) | \ 67 MAIR_ATTRIDX(MAIR_ATTR_NORMAL_NC, MT_NORMAL_NC) | \ 68 MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL) | \ 69 MAIR_ATTRIDX(MAIR_ATTR_NORMAL, MT_NORMAL_TAGGED)) 70 71#ifdef CONFIG_CPU_PM 72/** 73 * cpu_do_suspend - save CPU registers context 74 * 75 * x0: virtual address of context pointer 76 * 77 * This must be kept in sync with struct cpu_suspend_ctx in <asm/suspend.h>. 78 */ 79SYM_FUNC_START(cpu_do_suspend) 80 mrs x2, tpidr_el0 81 mrs x3, tpidrro_el0 82 mrs x4, contextidr_el1 83 mrs x5, osdlr_el1 84 mrs x6, cpacr_el1 85 mrs x7, tcr_el1 86 mrs x8, vbar_el1 87 mrs x9, mdscr_el1 88 mrs x10, oslsr_el1 89 mrs x11, sctlr_el1 90 get_this_cpu_offset x12 91 mrs x13, sp_el0 92 stp x2, x3, [x0] 93 stp x4, x5, [x0, #16] 94 stp x6, x7, [x0, #32] 95 stp x8, x9, [x0, #48] 96 stp x10, x11, [x0, #64] 97 stp x12, x13, [x0, #80] 98 /* 99 * Save x18 as it may be used as a platform register, e.g. by shadow 100 * call stack. 101 */ 102 str x18, [x0, #96] 103 ret 104SYM_FUNC_END(cpu_do_suspend) 105 106/** 107 * cpu_do_resume - restore CPU register context 108 * 109 * x0: Address of context pointer 110 */ 111SYM_FUNC_START(cpu_do_resume) 112 ldp x2, x3, [x0] 113 ldp x4, x5, [x0, #16] 114 ldp x6, x8, [x0, #32] 115 ldp x9, x10, [x0, #48] 116 ldp x11, x12, [x0, #64] 117 ldp x13, x14, [x0, #80] 118 /* 119 * Restore x18, as it may be used as a platform register, and clear 120 * the buffer to minimize the risk of exposure when used for shadow 121 * call stack. 122 */ 123 ldr x18, [x0, #96] 124 str xzr, [x0, #96] 125 msr tpidr_el0, x2 126 msr tpidrro_el0, x3 127 msr contextidr_el1, x4 128 msr cpacr_el1, x6 129 130 /* Don't change t0sz here, mask those bits when restoring */ 131 mrs x7, tcr_el1 132 bfi x8, x7, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH 133 134 msr tcr_el1, x8 135 msr vbar_el1, x9 136 msr mdscr_el1, x10 137 138 msr sctlr_el1, x12 139 set_this_cpu_offset x13 140 msr sp_el0, x14 141 /* 142 * Restore oslsr_el1 by writing oslar_el1 143 */ 144 msr osdlr_el1, x5 145 ubfx x11, x11, #1, #1 146 msr oslar_el1, x11 147 reset_pmuserenr_el0 x0 // Disable PMU access from EL0 148 reset_amuserenr_el0 x0 // Disable AMU access from EL0 149 150alternative_if ARM64_HAS_RAS_EXTN 151 msr_s SYS_DISR_EL1, xzr 152alternative_else_nop_endif 153 154 ptrauth_keys_install_kernel_nosync x14, x1, x2, x3 155 isb 156 ret 157SYM_FUNC_END(cpu_do_resume) 158#endif 159 160 .pushsection ".idmap.text", "a" 161 162.macro __idmap_cpu_set_reserved_ttbr1, tmp1, tmp2 163 adrp \tmp1, reserved_pg_dir 164 phys_to_ttbr \tmp2, \tmp1 165 offset_ttbr1 \tmp2, \tmp1 166 msr ttbr1_el1, \tmp2 167 isb 168 tlbi vmalle1 169 dsb nsh 170 isb 171.endm 172 173/* 174 * void idmap_cpu_replace_ttbr1(phys_addr_t ttbr1) 175 * 176 * This is the low-level counterpart to cpu_replace_ttbr1, and should not be 177 * called by anything else. It can only be executed from a TTBR0 mapping. 178 */ 179SYM_TYPED_FUNC_START(idmap_cpu_replace_ttbr1) 180 __idmap_cpu_set_reserved_ttbr1 x1, x3 181 182 offset_ttbr1 x0, x3 183 msr ttbr1_el1, x0 184 isb 185 186 ret 187SYM_FUNC_END(idmap_cpu_replace_ttbr1) 188SYM_FUNC_ALIAS(__pi_idmap_cpu_replace_ttbr1, idmap_cpu_replace_ttbr1) 189 .popsection 190 191#ifdef CONFIG_UNMAP_KERNEL_AT_EL0 192 193#define KPTI_NG_PTE_FLAGS (PTE_ATTRINDX(MT_NORMAL) | PTE_TYPE_PAGE | \ 194 PTE_AF | PTE_SHARED | PTE_UXN | PTE_WRITE) 195 196 .pushsection ".idmap.text", "a" 197 198 .macro pte_to_phys, phys, pte 199 and \phys, \pte, #PTE_ADDR_LOW 200#ifdef CONFIG_ARM64_PA_BITS_52 201 and \pte, \pte, #PTE_ADDR_HIGH 202 orr \phys, \phys, \pte, lsl #PTE_ADDR_HIGH_SHIFT 203#endif 204 .endm 205 206 .macro kpti_mk_tbl_ng, type, num_entries 207 add end_\type\()p, cur_\type\()p, #\num_entries * 8 208.Ldo_\type: 209 ldr \type, [cur_\type\()p], #8 // Load the entry and advance 210 tbz \type, #0, .Lnext_\type // Skip invalid and 211 tbnz \type, #11, .Lnext_\type // non-global entries 212 orr \type, \type, #PTE_NG // Same bit for blocks and pages 213 str \type, [cur_\type\()p, #-8] // Update the entry 214 .ifnc \type, pte 215 tbnz \type, #1, .Lderef_\type 216 .endif 217.Lnext_\type: 218 cmp cur_\type\()p, end_\type\()p 219 b.ne .Ldo_\type 220 .endm 221 222 /* 223 * Dereference the current table entry and map it into the temporary 224 * fixmap slot associated with the current level. 225 */ 226 .macro kpti_map_pgtbl, type, level 227 str xzr, [temp_pte, #8 * (\level + 2)] // break before make 228 dsb nshst 229 add pte, temp_pte, #PAGE_SIZE * (\level + 2) 230 lsr pte, pte, #12 231 tlbi vaae1, pte 232 dsb nsh 233 isb 234 235 phys_to_pte pte, cur_\type\()p 236 add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 2) 237 orr pte, pte, pte_flags 238 str pte, [temp_pte, #8 * (\level + 2)] 239 dsb nshst 240 .endm 241 242/* 243 * void __kpti_install_ng_mappings(int cpu, int num_secondaries, phys_addr_t temp_pgd, 244 * unsigned long temp_pte_va) 245 * 246 * Called exactly once from stop_machine context by each CPU found during boot. 247 */ 248 .pushsection ".data", "aw", %progbits 249SYM_DATA(__idmap_kpti_flag, .long 1) 250 .popsection 251 252SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) 253 cpu .req w0 254 temp_pte .req x0 255 num_cpus .req w1 256 pte_flags .req x1 257 temp_pgd_phys .req x2 258 swapper_ttb .req x3 259 flag_ptr .req x4 260 cur_pgdp .req x5 261 end_pgdp .req x6 262 pgd .req x7 263 cur_pudp .req x8 264 end_pudp .req x9 265 cur_pmdp .req x11 266 end_pmdp .req x12 267 cur_ptep .req x14 268 end_ptep .req x15 269 pte .req x16 270 valid .req x17 271 cur_p4dp .req x19 272 end_p4dp .req x20 273 274 mov x5, x3 // preserve temp_pte arg 275 mrs swapper_ttb, ttbr1_el1 276 adr_l flag_ptr, __idmap_kpti_flag 277 278 cbnz cpu, __idmap_kpti_secondary 279 280#if CONFIG_PGTABLE_LEVELS > 4 281 stp x29, x30, [sp, #-32]! 282 mov x29, sp 283 stp x19, x20, [sp, #16] 284#endif 285 286 /* We're the boot CPU. Wait for the others to catch up */ 287 sevl 2881: wfe 289 ldaxr w17, [flag_ptr] 290 eor w17, w17, num_cpus 291 cbnz w17, 1b 292 293 /* Switch to the temporary page tables on this CPU only */ 294 __idmap_cpu_set_reserved_ttbr1 x8, x9 295 offset_ttbr1 temp_pgd_phys, x8 296 msr ttbr1_el1, temp_pgd_phys 297 isb 298 299 mov temp_pte, x5 300 mov_q pte_flags, KPTI_NG_PTE_FLAGS 301 302 /* Everybody is enjoying the idmap, so we can rewrite swapper. */ 303 304#ifdef CONFIG_ARM64_LPA2 305 /* 306 * If LPA2 support is configured, but 52-bit virtual addressing is not 307 * enabled at runtime, we will fall back to one level of paging less, 308 * and so we have to walk swapper_pg_dir as if we dereferenced its 309 * address from a PGD level entry, and terminate the PGD level loop 310 * right after. 311 */ 312 adrp pgd, swapper_pg_dir // walk &swapper_pg_dir at the next level 313 mov cur_pgdp, end_pgdp // must be equal to terminate the PGD loop 314alternative_if_not ARM64_HAS_VA52 315 b .Lderef_pgd // skip to the next level 316alternative_else_nop_endif 317 /* 318 * LPA2 based 52-bit virtual addressing requires 52-bit physical 319 * addressing to be enabled as well. In this case, the shareability 320 * bits are repurposed as physical address bits, and should not be 321 * set in pte_flags. 322 */ 323 bic pte_flags, pte_flags, #PTE_SHARED 324#endif 325 326 /* PGD */ 327 adrp cur_pgdp, swapper_pg_dir 328 kpti_map_pgtbl pgd, -1 329 kpti_mk_tbl_ng pgd, PTRS_PER_PGD 330 331 /* Ensure all the updated entries are visible to secondary CPUs */ 332 dsb ishst 333 334 /* We're done: fire up swapper_pg_dir again */ 335 __idmap_cpu_set_reserved_ttbr1 x8, x9 336 msr ttbr1_el1, swapper_ttb 337 isb 338 339 /* Set the flag to zero to indicate that we're all done */ 340 str wzr, [flag_ptr] 341#if CONFIG_PGTABLE_LEVELS > 4 342 ldp x19, x20, [sp, #16] 343 ldp x29, x30, [sp], #32 344#endif 345 ret 346 347.Lderef_pgd: 348 /* P4D */ 349 .if CONFIG_PGTABLE_LEVELS > 4 350 p4d .req x30 351 pte_to_phys cur_p4dp, pgd 352 kpti_map_pgtbl p4d, 0 353 kpti_mk_tbl_ng p4d, PTRS_PER_P4D 354 b .Lnext_pgd 355 .else /* CONFIG_PGTABLE_LEVELS <= 4 */ 356 p4d .req pgd 357 .set .Lnext_p4d, .Lnext_pgd 358 .endif 359 360.Lderef_p4d: 361 /* PUD */ 362 .if CONFIG_PGTABLE_LEVELS > 3 363 pud .req x10 364 pte_to_phys cur_pudp, p4d 365 kpti_map_pgtbl pud, 1 366 kpti_mk_tbl_ng pud, PTRS_PER_PUD 367 b .Lnext_p4d 368 .else /* CONFIG_PGTABLE_LEVELS <= 3 */ 369 pud .req pgd 370 .set .Lnext_pud, .Lnext_pgd 371 .endif 372 373.Lderef_pud: 374 /* PMD */ 375 .if CONFIG_PGTABLE_LEVELS > 2 376 pmd .req x13 377 pte_to_phys cur_pmdp, pud 378 kpti_map_pgtbl pmd, 2 379 kpti_mk_tbl_ng pmd, PTRS_PER_PMD 380 b .Lnext_pud 381 .else /* CONFIG_PGTABLE_LEVELS <= 2 */ 382 pmd .req pgd 383 .set .Lnext_pmd, .Lnext_pgd 384 .endif 385 386.Lderef_pmd: 387 /* PTE */ 388 pte_to_phys cur_ptep, pmd 389 kpti_map_pgtbl pte, 3 390 kpti_mk_tbl_ng pte, PTRS_PER_PTE 391 b .Lnext_pmd 392 393 .unreq cpu 394 .unreq temp_pte 395 .unreq num_cpus 396 .unreq pte_flags 397 .unreq temp_pgd_phys 398 .unreq cur_pgdp 399 .unreq end_pgdp 400 .unreq pgd 401 .unreq cur_pudp 402 .unreq end_pudp 403 .unreq pud 404 .unreq cur_pmdp 405 .unreq end_pmdp 406 .unreq pmd 407 .unreq cur_ptep 408 .unreq end_ptep 409 .unreq pte 410 .unreq valid 411 .unreq cur_p4dp 412 .unreq end_p4dp 413 .unreq p4d 414 415 /* Secondary CPUs end up here */ 416__idmap_kpti_secondary: 417 /* Uninstall swapper before surgery begins */ 418 __idmap_cpu_set_reserved_ttbr1 x16, x17 419 420 /* Increment the flag to let the boot CPU we're ready */ 4211: ldxr w16, [flag_ptr] 422 add w16, w16, #1 423 stxr w17, w16, [flag_ptr] 424 cbnz w17, 1b 425 426 /* Wait for the boot CPU to finish messing around with swapper */ 427 sevl 4281: wfe 429 ldxr w16, [flag_ptr] 430 cbnz w16, 1b 431 432 /* All done, act like nothing happened */ 433 msr ttbr1_el1, swapper_ttb 434 isb 435 ret 436 437 .unreq swapper_ttb 438 .unreq flag_ptr 439SYM_FUNC_END(idmap_kpti_install_ng_mappings) 440 .popsection 441#endif 442 443/* 444 * __cpu_setup 445 * 446 * Initialise the processor for turning the MMU on. 447 * 448 * Output: 449 * Return in x0 the value of the SCTLR_EL1 register. 450 */ 451 .pushsection ".idmap.text", "a" 452SYM_FUNC_START(__cpu_setup) 453 tlbi vmalle1 // Invalidate local TLB 454 dsb nsh 455 456 msr cpacr_el1, xzr // Reset cpacr_el1 457 mov x1, #1 << 12 // Reset mdscr_el1 and disable 458 msr mdscr_el1, x1 // access to the DCC from EL0 459 reset_pmuserenr_el0 x1 // Disable PMU access from EL0 460 reset_amuserenr_el0 x1 // Disable AMU access from EL0 461 462 /* 463 * Default values for VMSA control registers. These will be adjusted 464 * below depending on detected CPU features. 465 */ 466 mair .req x17 467 tcr .req x16 468 mov_q mair, MAIR_EL1_SET 469 mov_q tcr, TCR_T0SZ(IDMAP_VA_BITS) | TCR_T1SZ(VA_BITS_MIN) | TCR_CACHE_FLAGS | \ 470 TCR_SHARED | TCR_TG_FLAGS | TCR_KASLR_FLAGS | TCR_ASID16 | \ 471 TCR_TBI0 | TCR_A1 | TCR_KASAN_SW_FLAGS | TCR_MTE_FLAGS 472 473 tcr_clear_errata_bits tcr, x9, x5 474 475#ifdef CONFIG_ARM64_VA_BITS_52 476 mov x9, #64 - VA_BITS 477alternative_if ARM64_HAS_VA52 478 tcr_set_t1sz tcr, x9 479#ifdef CONFIG_ARM64_LPA2 480 orr tcr, tcr, #TCR_DS 481#endif 482alternative_else_nop_endif 483#endif 484 485 /* 486 * Set the IPS bits in TCR_EL1. 487 */ 488 tcr_compute_pa_size tcr, #TCR_IPS_SHIFT, x5, x6 489#ifdef CONFIG_ARM64_HW_AFDBM 490 /* 491 * Enable hardware update of the Access Flags bit. 492 * Hardware dirty bit management is enabled later, 493 * via capabilities. 494 */ 495 mrs x9, ID_AA64MMFR1_EL1 496 and x9, x9, ID_AA64MMFR1_EL1_HAFDBS_MASK 497 cbz x9, 1f 498 orr tcr, tcr, #TCR_HA // hardware Access flag update 4991: 500#endif /* CONFIG_ARM64_HW_AFDBM */ 501 msr mair_el1, mair 502 msr tcr_el1, tcr 503 504 mrs_s x1, SYS_ID_AA64MMFR3_EL1 505 ubfx x1, x1, #ID_AA64MMFR3_EL1_S1PIE_SHIFT, #4 506 cbz x1, .Lskip_indirection 507 508 /* 509 * The PROT_* macros describing the various memory types may resolve to 510 * C expressions if they include the PTE_MAYBE_* macros, and so they 511 * can only be used from C code. The PIE_E* constants below are also 512 * defined in terms of those macros, but will mask out those 513 * PTE_MAYBE_* constants, whether they are set or not. So #define them 514 * as 0x0 here so we can evaluate the PIE_E* constants in asm context. 515 */ 516 517#define PTE_MAYBE_NG 0 518#define PTE_MAYBE_SHARED 0 519 520 mov_q x0, PIE_E0 521 msr REG_PIRE0_EL1, x0 522 mov_q x0, PIE_E1 523 msr REG_PIR_EL1, x0 524 525#undef PTE_MAYBE_NG 526#undef PTE_MAYBE_SHARED 527 528 mov x0, TCR2_EL1x_PIE 529 msr REG_TCR2_EL1, x0 530 531.Lskip_indirection: 532 533 /* 534 * Prepare SCTLR 535 */ 536 mov_q x0, INIT_SCTLR_EL1_MMU_ON 537 ret // return to head.S 538 539 .unreq mair 540 .unreq tcr 541SYM_FUNC_END(__cpu_setup) 542