1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012 Regents of the University of California 4 * Copyright (C) 2019 Western Digital Corporation or its affiliates. 5 * Copyright (C) 2020 FORTH-ICS/CARV 6 * Nick Kossifidis <mick@ics.forth.gr> 7 */ 8 9 #include <linux/init.h> 10 #include <linux/mm.h> 11 #include <linux/memblock.h> 12 #include <linux/initrd.h> 13 #include <linux/swap.h> 14 #include <linux/swiotlb.h> 15 #include <linux/sizes.h> 16 #include <linux/of_fdt.h> 17 #include <linux/of_reserved_mem.h> 18 #include <linux/libfdt.h> 19 #include <linux/set_memory.h> 20 #include <linux/dma-map-ops.h> 21 #include <linux/crash_dump.h> 22 #include <linux/hugetlb.h> 23 #ifdef CONFIG_RELOCATABLE 24 #include <linux/elf.h> 25 #endif 26 #include <linux/kfence.h> 27 28 #include <asm/fixmap.h> 29 #include <asm/io.h> 30 #include <asm/numa.h> 31 #include <asm/pgtable.h> 32 #include <asm/sections.h> 33 #include <asm/soc.h> 34 #include <asm/tlbflush.h> 35 36 #include "../kernel/head.h" 37 38 struct kernel_mapping kernel_map __ro_after_init; 39 EXPORT_SYMBOL(kernel_map); 40 #ifdef CONFIG_XIP_KERNEL 41 #define kernel_map (*(struct kernel_mapping *)XIP_FIXUP(&kernel_map)) 42 #endif 43 44 #ifdef CONFIG_64BIT 45 u64 satp_mode __ro_after_init = !IS_ENABLED(CONFIG_XIP_KERNEL) ? SATP_MODE_57 : SATP_MODE_39; 46 #else 47 u64 satp_mode __ro_after_init = SATP_MODE_32; 48 #endif 49 EXPORT_SYMBOL(satp_mode); 50 51 #ifdef CONFIG_64BIT 52 bool pgtable_l4_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL); 53 bool pgtable_l5_enabled = IS_ENABLED(CONFIG_64BIT) && !IS_ENABLED(CONFIG_XIP_KERNEL); 54 EXPORT_SYMBOL(pgtable_l4_enabled); 55 EXPORT_SYMBOL(pgtable_l5_enabled); 56 #endif 57 58 phys_addr_t phys_ram_base __ro_after_init; 59 EXPORT_SYMBOL(phys_ram_base); 60 61 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] 62 __page_aligned_bss; 63 EXPORT_SYMBOL(empty_zero_page); 64 65 extern char _start[]; 66 void *_dtb_early_va __initdata; 67 uintptr_t _dtb_early_pa __initdata; 68 69 phys_addr_t dma32_phys_limit __initdata; 70 71 static void __init zone_sizes_init(void) 72 { 73 unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; 74 75 #ifdef CONFIG_ZONE_DMA32 76 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit); 77 #endif 78 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 79 80 free_area_init(max_zone_pfns); 81 } 82 83 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM) 84 85 #define LOG2_SZ_1K ilog2(SZ_1K) 86 #define LOG2_SZ_1M ilog2(SZ_1M) 87 #define LOG2_SZ_1G ilog2(SZ_1G) 88 #define LOG2_SZ_1T ilog2(SZ_1T) 89 90 static inline void print_mlk(char *name, unsigned long b, unsigned long t) 91 { 92 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld kB)\n", name, b, t, 93 (((t) - (b)) >> LOG2_SZ_1K)); 94 } 95 96 static inline void print_mlm(char *name, unsigned long b, unsigned long t) 97 { 98 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld MB)\n", name, b, t, 99 (((t) - (b)) >> LOG2_SZ_1M)); 100 } 101 102 static inline void print_mlg(char *name, unsigned long b, unsigned long t) 103 { 104 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld GB)\n", name, b, t, 105 (((t) - (b)) >> LOG2_SZ_1G)); 106 } 107 108 #ifdef CONFIG_64BIT 109 static inline void print_mlt(char *name, unsigned long b, unsigned long t) 110 { 111 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld TB)\n", name, b, t, 112 (((t) - (b)) >> LOG2_SZ_1T)); 113 } 114 #else 115 #define print_mlt(n, b, t) do {} while (0) 116 #endif 117 118 static inline void print_ml(char *name, unsigned long b, unsigned long t) 119 { 120 unsigned long diff = t - b; 121 122 if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10) 123 print_mlt(name, b, t); 124 else if ((diff >> LOG2_SZ_1G) >= 10) 125 print_mlg(name, b, t); 126 else if ((diff >> LOG2_SZ_1M) >= 10) 127 print_mlm(name, b, t); 128 else 129 print_mlk(name, b, t); 130 } 131 132 static void __init print_vm_layout(void) 133 { 134 pr_notice("Virtual kernel memory layout:\n"); 135 print_ml("fixmap", (unsigned long)FIXADDR_START, 136 (unsigned long)FIXADDR_TOP); 137 print_ml("pci io", (unsigned long)PCI_IO_START, 138 (unsigned long)PCI_IO_END); 139 print_ml("vmemmap", (unsigned long)VMEMMAP_START, 140 (unsigned long)VMEMMAP_END); 141 print_ml("vmalloc", (unsigned long)VMALLOC_START, 142 (unsigned long)VMALLOC_END); 143 #ifdef CONFIG_64BIT 144 print_ml("modules", (unsigned long)MODULES_VADDR, 145 (unsigned long)MODULES_END); 146 #endif 147 print_ml("lowmem", (unsigned long)PAGE_OFFSET, 148 (unsigned long)high_memory); 149 if (IS_ENABLED(CONFIG_64BIT)) { 150 #ifdef CONFIG_KASAN 151 print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END); 152 #endif 153 154 print_ml("kernel", (unsigned long)kernel_map.virt_addr, 155 (unsigned long)ADDRESS_SPACE_END); 156 } 157 } 158 #else 159 static void print_vm_layout(void) { } 160 #endif /* CONFIG_DEBUG_VM */ 161 162 void __init mem_init(void) 163 { 164 #ifdef CONFIG_FLATMEM 165 BUG_ON(!mem_map); 166 #endif /* CONFIG_FLATMEM */ 167 168 swiotlb_init(max_pfn > PFN_DOWN(dma32_phys_limit), SWIOTLB_VERBOSE); 169 memblock_free_all(); 170 171 print_vm_layout(); 172 } 173 174 /* Limit the memory size via mem. */ 175 static phys_addr_t memory_limit; 176 #ifdef CONFIG_XIP_KERNEL 177 #define memory_limit (*(phys_addr_t *)XIP_FIXUP(&memory_limit)) 178 #endif /* CONFIG_XIP_KERNEL */ 179 180 static int __init early_mem(char *p) 181 { 182 u64 size; 183 184 if (!p) 185 return 1; 186 187 size = memparse(p, &p) & PAGE_MASK; 188 memory_limit = min_t(u64, size, memory_limit); 189 190 pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20); 191 192 return 0; 193 } 194 early_param("mem", early_mem); 195 196 static void __init setup_bootmem(void) 197 { 198 phys_addr_t vmlinux_end = __pa_symbol(&_end); 199 phys_addr_t max_mapped_addr; 200 phys_addr_t phys_ram_end, vmlinux_start; 201 202 if (IS_ENABLED(CONFIG_XIP_KERNEL)) 203 vmlinux_start = __pa_symbol(&_sdata); 204 else 205 vmlinux_start = __pa_symbol(&_start); 206 207 memblock_enforce_memory_limit(memory_limit); 208 209 /* 210 * Make sure we align the reservation on PMD_SIZE since we will 211 * map the kernel in the linear mapping as read-only: we do not want 212 * any allocation to happen between _end and the next pmd aligned page. 213 */ 214 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) 215 vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK; 216 /* 217 * Reserve from the start of the kernel to the end of the kernel 218 */ 219 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); 220 221 phys_ram_end = memblock_end_of_DRAM(); 222 223 /* 224 * Make sure we align the start of the memory on a PMD boundary so that 225 * at worst, we map the linear mapping with PMD mappings. 226 */ 227 if (!IS_ENABLED(CONFIG_XIP_KERNEL)) 228 phys_ram_base = memblock_start_of_DRAM() & PMD_MASK; 229 230 /* 231 * In 64-bit, any use of __va/__pa before this point is wrong as we 232 * did not know the start of DRAM before. 233 */ 234 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) 235 kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base; 236 237 /* 238 * memblock allocator is not aware of the fact that last 4K bytes of 239 * the addressable memory can not be mapped because of IS_ERR_VALUE 240 * macro. Make sure that last 4k bytes are not usable by memblock 241 * if end of dram is equal to maximum addressable memory. For 64-bit 242 * kernel, this problem can't happen here as the end of the virtual 243 * address space is occupied by the kernel mapping then this check must 244 * be done as soon as the kernel mapping base address is determined. 245 */ 246 if (!IS_ENABLED(CONFIG_64BIT)) { 247 max_mapped_addr = __pa(~(ulong)0); 248 if (max_mapped_addr == (phys_ram_end - 1)) 249 memblock_set_current_limit(max_mapped_addr - 4096); 250 } 251 252 min_low_pfn = PFN_UP(phys_ram_base); 253 max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end); 254 high_memory = (void *)(__va(PFN_PHYS(max_low_pfn))); 255 256 dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn)); 257 set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET); 258 259 reserve_initrd_mem(); 260 261 /* 262 * No allocation should be done before reserving the memory as defined 263 * in the device tree, otherwise the allocation could end up in a 264 * reserved region. 265 */ 266 early_init_fdt_scan_reserved_mem(); 267 268 /* 269 * If DTB is built in, no need to reserve its memblock. 270 * Otherwise, do reserve it but avoid using 271 * early_init_fdt_reserve_self() since __pa() does 272 * not work for DTB pointers that are fixmap addresses 273 */ 274 if (!IS_ENABLED(CONFIG_BUILTIN_DTB)) 275 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); 276 277 dma_contiguous_reserve(dma32_phys_limit); 278 if (IS_ENABLED(CONFIG_64BIT)) 279 hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT); 280 } 281 282 #ifdef CONFIG_MMU 283 struct pt_alloc_ops pt_ops __initdata; 284 285 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 286 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 287 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 288 289 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 290 291 #ifdef CONFIG_XIP_KERNEL 292 #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops)) 293 #define trampoline_pg_dir ((pgd_t *)XIP_FIXUP(trampoline_pg_dir)) 294 #define fixmap_pte ((pte_t *)XIP_FIXUP(fixmap_pte)) 295 #define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir)) 296 #endif /* CONFIG_XIP_KERNEL */ 297 298 static const pgprot_t protection_map[16] = { 299 [VM_NONE] = PAGE_NONE, 300 [VM_READ] = PAGE_READ, 301 [VM_WRITE] = PAGE_COPY, 302 [VM_WRITE | VM_READ] = PAGE_COPY, 303 [VM_EXEC] = PAGE_EXEC, 304 [VM_EXEC | VM_READ] = PAGE_READ_EXEC, 305 [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC, 306 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC, 307 [VM_SHARED] = PAGE_NONE, 308 [VM_SHARED | VM_READ] = PAGE_READ, 309 [VM_SHARED | VM_WRITE] = PAGE_SHARED, 310 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, 311 [VM_SHARED | VM_EXEC] = PAGE_EXEC, 312 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READ_EXEC, 313 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC, 314 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC 315 }; 316 DECLARE_VM_GET_PAGE_PROT 317 318 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 319 { 320 unsigned long addr = __fix_to_virt(idx); 321 pte_t *ptep; 322 323 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 324 325 ptep = &fixmap_pte[pte_index(addr)]; 326 327 if (pgprot_val(prot)) 328 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 329 else 330 pte_clear(&init_mm, addr, ptep); 331 local_flush_tlb_page(addr); 332 } 333 334 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa) 335 { 336 return (pte_t *)((uintptr_t)pa); 337 } 338 339 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa) 340 { 341 clear_fixmap(FIX_PTE); 342 return (pte_t *)set_fixmap_offset(FIX_PTE, pa); 343 } 344 345 static inline pte_t *__init get_pte_virt_late(phys_addr_t pa) 346 { 347 return (pte_t *) __va(pa); 348 } 349 350 static inline phys_addr_t __init alloc_pte_early(uintptr_t va) 351 { 352 /* 353 * We only create PMD or PGD early mappings so we 354 * should never reach here with MMU disabled. 355 */ 356 BUG(); 357 } 358 359 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va) 360 { 361 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 362 } 363 364 static phys_addr_t __init alloc_pte_late(uintptr_t va) 365 { 366 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0); 367 368 BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc)); 369 return __pa((pte_t *)ptdesc_address(ptdesc)); 370 } 371 372 static void __init create_pte_mapping(pte_t *ptep, 373 uintptr_t va, phys_addr_t pa, 374 phys_addr_t sz, pgprot_t prot) 375 { 376 uintptr_t pte_idx = pte_index(va); 377 378 BUG_ON(sz != PAGE_SIZE); 379 380 if (pte_none(ptep[pte_idx])) 381 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot); 382 } 383 384 #ifndef __PAGETABLE_PMD_FOLDED 385 386 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss; 387 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 388 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); 389 390 #ifdef CONFIG_XIP_KERNEL 391 #define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd)) 392 #define fixmap_pmd ((pmd_t *)XIP_FIXUP(fixmap_pmd)) 393 #define early_pmd ((pmd_t *)XIP_FIXUP(early_pmd)) 394 #endif /* CONFIG_XIP_KERNEL */ 395 396 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss; 397 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss; 398 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE); 399 400 #ifdef CONFIG_XIP_KERNEL 401 #define trampoline_p4d ((p4d_t *)XIP_FIXUP(trampoline_p4d)) 402 #define fixmap_p4d ((p4d_t *)XIP_FIXUP(fixmap_p4d)) 403 #define early_p4d ((p4d_t *)XIP_FIXUP(early_p4d)) 404 #endif /* CONFIG_XIP_KERNEL */ 405 406 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss; 407 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss; 408 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE); 409 410 #ifdef CONFIG_XIP_KERNEL 411 #define trampoline_pud ((pud_t *)XIP_FIXUP(trampoline_pud)) 412 #define fixmap_pud ((pud_t *)XIP_FIXUP(fixmap_pud)) 413 #define early_pud ((pud_t *)XIP_FIXUP(early_pud)) 414 #endif /* CONFIG_XIP_KERNEL */ 415 416 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa) 417 { 418 /* Before MMU is enabled */ 419 return (pmd_t *)((uintptr_t)pa); 420 } 421 422 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa) 423 { 424 clear_fixmap(FIX_PMD); 425 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); 426 } 427 428 static pmd_t *__init get_pmd_virt_late(phys_addr_t pa) 429 { 430 return (pmd_t *) __va(pa); 431 } 432 433 static phys_addr_t __init alloc_pmd_early(uintptr_t va) 434 { 435 BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT); 436 437 return (uintptr_t)early_pmd; 438 } 439 440 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va) 441 { 442 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 443 } 444 445 static phys_addr_t __init alloc_pmd_late(uintptr_t va) 446 { 447 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0); 448 449 BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc)); 450 return __pa((pmd_t *)ptdesc_address(ptdesc)); 451 } 452 453 static void __init create_pmd_mapping(pmd_t *pmdp, 454 uintptr_t va, phys_addr_t pa, 455 phys_addr_t sz, pgprot_t prot) 456 { 457 pte_t *ptep; 458 phys_addr_t pte_phys; 459 uintptr_t pmd_idx = pmd_index(va); 460 461 if (sz == PMD_SIZE) { 462 if (pmd_none(pmdp[pmd_idx])) 463 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot); 464 return; 465 } 466 467 if (pmd_none(pmdp[pmd_idx])) { 468 pte_phys = pt_ops.alloc_pte(va); 469 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); 470 ptep = pt_ops.get_pte_virt(pte_phys); 471 memset(ptep, 0, PAGE_SIZE); 472 } else { 473 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx])); 474 ptep = pt_ops.get_pte_virt(pte_phys); 475 } 476 477 create_pte_mapping(ptep, va, pa, sz, prot); 478 } 479 480 static pud_t *__init get_pud_virt_early(phys_addr_t pa) 481 { 482 return (pud_t *)((uintptr_t)pa); 483 } 484 485 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa) 486 { 487 clear_fixmap(FIX_PUD); 488 return (pud_t *)set_fixmap_offset(FIX_PUD, pa); 489 } 490 491 static pud_t *__init get_pud_virt_late(phys_addr_t pa) 492 { 493 return (pud_t *)__va(pa); 494 } 495 496 static phys_addr_t __init alloc_pud_early(uintptr_t va) 497 { 498 /* Only one PUD is available for early mapping */ 499 BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT); 500 501 return (uintptr_t)early_pud; 502 } 503 504 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va) 505 { 506 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 507 } 508 509 static phys_addr_t alloc_pud_late(uintptr_t va) 510 { 511 unsigned long vaddr; 512 513 vaddr = __get_free_page(GFP_KERNEL); 514 BUG_ON(!vaddr); 515 return __pa(vaddr); 516 } 517 518 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa) 519 { 520 return (p4d_t *)((uintptr_t)pa); 521 } 522 523 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa) 524 { 525 clear_fixmap(FIX_P4D); 526 return (p4d_t *)set_fixmap_offset(FIX_P4D, pa); 527 } 528 529 static p4d_t *__init get_p4d_virt_late(phys_addr_t pa) 530 { 531 return (p4d_t *)__va(pa); 532 } 533 534 static phys_addr_t __init alloc_p4d_early(uintptr_t va) 535 { 536 /* Only one P4D is available for early mapping */ 537 BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT); 538 539 return (uintptr_t)early_p4d; 540 } 541 542 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va) 543 { 544 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 545 } 546 547 static phys_addr_t alloc_p4d_late(uintptr_t va) 548 { 549 unsigned long vaddr; 550 551 vaddr = __get_free_page(GFP_KERNEL); 552 BUG_ON(!vaddr); 553 return __pa(vaddr); 554 } 555 556 static void __init create_pud_mapping(pud_t *pudp, 557 uintptr_t va, phys_addr_t pa, 558 phys_addr_t sz, pgprot_t prot) 559 { 560 pmd_t *nextp; 561 phys_addr_t next_phys; 562 uintptr_t pud_index = pud_index(va); 563 564 if (sz == PUD_SIZE) { 565 if (pud_val(pudp[pud_index]) == 0) 566 pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot); 567 return; 568 } 569 570 if (pud_val(pudp[pud_index]) == 0) { 571 next_phys = pt_ops.alloc_pmd(va); 572 pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE); 573 nextp = pt_ops.get_pmd_virt(next_phys); 574 memset(nextp, 0, PAGE_SIZE); 575 } else { 576 next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index])); 577 nextp = pt_ops.get_pmd_virt(next_phys); 578 } 579 580 create_pmd_mapping(nextp, va, pa, sz, prot); 581 } 582 583 static void __init create_p4d_mapping(p4d_t *p4dp, 584 uintptr_t va, phys_addr_t pa, 585 phys_addr_t sz, pgprot_t prot) 586 { 587 pud_t *nextp; 588 phys_addr_t next_phys; 589 uintptr_t p4d_index = p4d_index(va); 590 591 if (sz == P4D_SIZE) { 592 if (p4d_val(p4dp[p4d_index]) == 0) 593 p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot); 594 return; 595 } 596 597 if (p4d_val(p4dp[p4d_index]) == 0) { 598 next_phys = pt_ops.alloc_pud(va); 599 p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE); 600 nextp = pt_ops.get_pud_virt(next_phys); 601 memset(nextp, 0, PAGE_SIZE); 602 } else { 603 next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index])); 604 nextp = pt_ops.get_pud_virt(next_phys); 605 } 606 607 create_pud_mapping(nextp, va, pa, sz, prot); 608 } 609 610 #define pgd_next_t p4d_t 611 #define alloc_pgd_next(__va) (pgtable_l5_enabled ? \ 612 pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ? \ 613 pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va))) 614 #define get_pgd_next_virt(__pa) (pgtable_l5_enabled ? \ 615 pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ? \ 616 pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa))) 617 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 618 (pgtable_l5_enabled ? \ 619 create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \ 620 (pgtable_l4_enabled ? \ 621 create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) : \ 622 create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot))) 623 #define fixmap_pgd_next (pgtable_l5_enabled ? \ 624 (uintptr_t)fixmap_p4d : (pgtable_l4_enabled ? \ 625 (uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd)) 626 #define trampoline_pgd_next (pgtable_l5_enabled ? \ 627 (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \ 628 (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd)) 629 #else 630 #define pgd_next_t pte_t 631 #define alloc_pgd_next(__va) pt_ops.alloc_pte(__va) 632 #define get_pgd_next_virt(__pa) pt_ops.get_pte_virt(__pa) 633 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 634 create_pte_mapping(__nextp, __va, __pa, __sz, __prot) 635 #define fixmap_pgd_next ((uintptr_t)fixmap_pte) 636 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) 637 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) 638 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) 639 #endif /* __PAGETABLE_PMD_FOLDED */ 640 641 void __init create_pgd_mapping(pgd_t *pgdp, 642 uintptr_t va, phys_addr_t pa, 643 phys_addr_t sz, pgprot_t prot) 644 { 645 pgd_next_t *nextp; 646 phys_addr_t next_phys; 647 uintptr_t pgd_idx = pgd_index(va); 648 649 if (sz == PGDIR_SIZE) { 650 if (pgd_val(pgdp[pgd_idx]) == 0) 651 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot); 652 return; 653 } 654 655 if (pgd_val(pgdp[pgd_idx]) == 0) { 656 next_phys = alloc_pgd_next(va); 657 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE); 658 nextp = get_pgd_next_virt(next_phys); 659 memset(nextp, 0, PAGE_SIZE); 660 } else { 661 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx])); 662 nextp = get_pgd_next_virt(next_phys); 663 } 664 665 create_pgd_next_mapping(nextp, va, pa, sz, prot); 666 } 667 668 static uintptr_t __init best_map_size(phys_addr_t pa, uintptr_t va, 669 phys_addr_t size) 670 { 671 if (pgtable_l5_enabled && 672 !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) 673 return P4D_SIZE; 674 675 if (pgtable_l4_enabled && 676 !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) 677 return PUD_SIZE; 678 679 if (IS_ENABLED(CONFIG_64BIT) && 680 !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) 681 return PMD_SIZE; 682 683 return PAGE_SIZE; 684 } 685 686 #ifdef CONFIG_XIP_KERNEL 687 #define phys_ram_base (*(phys_addr_t *)XIP_FIXUP(&phys_ram_base)) 688 extern char _xiprom[], _exiprom[], __data_loc; 689 690 /* called from head.S with MMU off */ 691 asmlinkage void __init __copy_data(void) 692 { 693 void *from = (void *)(&__data_loc); 694 void *to = (void *)CONFIG_PHYS_RAM_BASE; 695 size_t sz = (size_t)((uintptr_t)(&_end) - (uintptr_t)(&_sdata)); 696 697 memcpy(to, from, sz); 698 } 699 #endif 700 701 #ifdef CONFIG_STRICT_KERNEL_RWX 702 static __init pgprot_t pgprot_from_va(uintptr_t va) 703 { 704 if (is_va_kernel_text(va)) 705 return PAGE_KERNEL_READ_EXEC; 706 707 /* 708 * In 64-bit kernel, the kernel mapping is outside the linear mapping so 709 * we must protect its linear mapping alias from being executed and 710 * written. 711 * And rodata section is marked readonly in mark_rodata_ro. 712 */ 713 if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va)) 714 return PAGE_KERNEL_READ; 715 716 return PAGE_KERNEL; 717 } 718 719 void mark_rodata_ro(void) 720 { 721 set_kernel_memory(__start_rodata, _data, set_memory_ro); 722 if (IS_ENABLED(CONFIG_64BIT)) 723 set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data), 724 set_memory_ro); 725 } 726 #else 727 static __init pgprot_t pgprot_from_va(uintptr_t va) 728 { 729 if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va)) 730 return PAGE_KERNEL; 731 732 return PAGE_KERNEL_EXEC; 733 } 734 #endif /* CONFIG_STRICT_KERNEL_RWX */ 735 736 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) 737 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa); 738 739 static void __init disable_pgtable_l5(void) 740 { 741 pgtable_l5_enabled = false; 742 kernel_map.page_offset = PAGE_OFFSET_L4; 743 satp_mode = SATP_MODE_48; 744 } 745 746 static void __init disable_pgtable_l4(void) 747 { 748 pgtable_l4_enabled = false; 749 kernel_map.page_offset = PAGE_OFFSET_L3; 750 satp_mode = SATP_MODE_39; 751 } 752 753 static int __init print_no4lvl(char *p) 754 { 755 pr_info("Disabled 4-level and 5-level paging"); 756 return 0; 757 } 758 early_param("no4lvl", print_no4lvl); 759 760 static int __init print_no5lvl(char *p) 761 { 762 pr_info("Disabled 5-level paging"); 763 return 0; 764 } 765 early_param("no5lvl", print_no5lvl); 766 767 static void __init set_mmap_rnd_bits_max(void) 768 { 769 mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3; 770 } 771 772 /* 773 * There is a simple way to determine if 4-level is supported by the 774 * underlying hardware: establish 1:1 mapping in 4-level page table mode 775 * then read SATP to see if the configuration was taken into account 776 * meaning sv48 is supported. 777 */ 778 static __init void set_satp_mode(uintptr_t dtb_pa) 779 { 780 u64 identity_satp, hw_satp; 781 uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK; 782 u64 satp_mode_cmdline = __pi_set_satp_mode_from_cmdline(dtb_pa); 783 784 if (satp_mode_cmdline == SATP_MODE_57) { 785 disable_pgtable_l5(); 786 } else if (satp_mode_cmdline == SATP_MODE_48) { 787 disable_pgtable_l5(); 788 disable_pgtable_l4(); 789 return; 790 } 791 792 create_p4d_mapping(early_p4d, 793 set_satp_mode_pmd, (uintptr_t)early_pud, 794 P4D_SIZE, PAGE_TABLE); 795 create_pud_mapping(early_pud, 796 set_satp_mode_pmd, (uintptr_t)early_pmd, 797 PUD_SIZE, PAGE_TABLE); 798 /* Handle the case where set_satp_mode straddles 2 PMDs */ 799 create_pmd_mapping(early_pmd, 800 set_satp_mode_pmd, set_satp_mode_pmd, 801 PMD_SIZE, PAGE_KERNEL_EXEC); 802 create_pmd_mapping(early_pmd, 803 set_satp_mode_pmd + PMD_SIZE, 804 set_satp_mode_pmd + PMD_SIZE, 805 PMD_SIZE, PAGE_KERNEL_EXEC); 806 retry: 807 create_pgd_mapping(early_pg_dir, 808 set_satp_mode_pmd, 809 pgtable_l5_enabled ? 810 (uintptr_t)early_p4d : (uintptr_t)early_pud, 811 PGDIR_SIZE, PAGE_TABLE); 812 813 identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode; 814 815 local_flush_tlb_all(); 816 csr_write(CSR_SATP, identity_satp); 817 hw_satp = csr_swap(CSR_SATP, 0ULL); 818 local_flush_tlb_all(); 819 820 if (hw_satp != identity_satp) { 821 if (pgtable_l5_enabled) { 822 disable_pgtable_l5(); 823 memset(early_pg_dir, 0, PAGE_SIZE); 824 goto retry; 825 } 826 disable_pgtable_l4(); 827 } 828 829 memset(early_pg_dir, 0, PAGE_SIZE); 830 memset(early_p4d, 0, PAGE_SIZE); 831 memset(early_pud, 0, PAGE_SIZE); 832 memset(early_pmd, 0, PAGE_SIZE); 833 } 834 #endif 835 836 /* 837 * setup_vm() is called from head.S with MMU-off. 838 * 839 * Following requirements should be honoured for setup_vm() to work 840 * correctly: 841 * 1) It should use PC-relative addressing for accessing kernel symbols. 842 * To achieve this we always use GCC cmodel=medany. 843 * 2) The compiler instrumentation for FTRACE will not work for setup_vm() 844 * so disable compiler instrumentation when FTRACE is enabled. 845 * 846 * Currently, the above requirements are honoured by using custom CFLAGS 847 * for init.o in mm/Makefile. 848 */ 849 850 #ifndef __riscv_cmodel_medany 851 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." 852 #endif 853 854 #ifdef CONFIG_RELOCATABLE 855 extern unsigned long __rela_dyn_start, __rela_dyn_end; 856 857 static void __init relocate_kernel(void) 858 { 859 Elf64_Rela *rela = (Elf64_Rela *)&__rela_dyn_start; 860 /* 861 * This holds the offset between the linked virtual address and the 862 * relocated virtual address. 863 */ 864 uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR; 865 /* 866 * This holds the offset between kernel linked virtual address and 867 * physical address. 868 */ 869 uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr; 870 871 for ( ; rela < (Elf64_Rela *)&__rela_dyn_end; rela++) { 872 Elf64_Addr addr = (rela->r_offset - va_kernel_link_pa_offset); 873 Elf64_Addr relocated_addr = rela->r_addend; 874 875 if (rela->r_info != R_RISCV_RELATIVE) 876 continue; 877 878 /* 879 * Make sure to not relocate vdso symbols like rt_sigreturn 880 * which are linked from the address 0 in vmlinux since 881 * vdso symbol addresses are actually used as an offset from 882 * mm->context.vdso in VDSO_OFFSET macro. 883 */ 884 if (relocated_addr >= KERNEL_LINK_ADDR) 885 relocated_addr += reloc_offset; 886 887 *(Elf64_Addr *)addr = relocated_addr; 888 } 889 } 890 #endif /* CONFIG_RELOCATABLE */ 891 892 #ifdef CONFIG_XIP_KERNEL 893 static void __init create_kernel_page_table(pgd_t *pgdir, 894 __always_unused bool early) 895 { 896 uintptr_t va, end_va; 897 898 /* Map the flash resident part */ 899 end_va = kernel_map.virt_addr + kernel_map.xiprom_sz; 900 for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE) 901 create_pgd_mapping(pgdir, va, 902 kernel_map.xiprom + (va - kernel_map.virt_addr), 903 PMD_SIZE, PAGE_KERNEL_EXEC); 904 905 /* Map the data in RAM */ 906 end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size; 907 for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += PMD_SIZE) 908 create_pgd_mapping(pgdir, va, 909 kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)), 910 PMD_SIZE, PAGE_KERNEL); 911 } 912 #else 913 static void __init create_kernel_page_table(pgd_t *pgdir, bool early) 914 { 915 uintptr_t va, end_va; 916 917 end_va = kernel_map.virt_addr + kernel_map.size; 918 for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE) 919 create_pgd_mapping(pgdir, va, 920 kernel_map.phys_addr + (va - kernel_map.virt_addr), 921 PMD_SIZE, 922 early ? 923 PAGE_KERNEL_EXEC : pgprot_from_va(va)); 924 } 925 #endif 926 927 /* 928 * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel, 929 * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR 930 * entry. 931 */ 932 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va, 933 uintptr_t dtb_pa) 934 { 935 #ifndef CONFIG_BUILTIN_DTB 936 uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1); 937 938 /* Make sure the fdt fixmap address is always aligned on PMD size */ 939 BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE)); 940 941 /* In 32-bit only, the fdt lies in its own PGD */ 942 if (!IS_ENABLED(CONFIG_64BIT)) { 943 create_pgd_mapping(early_pg_dir, fix_fdt_va, 944 pa, MAX_FDT_SIZE, PAGE_KERNEL); 945 } else { 946 create_pmd_mapping(fixmap_pmd, fix_fdt_va, 947 pa, PMD_SIZE, PAGE_KERNEL); 948 create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE, 949 pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL); 950 } 951 952 dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1)); 953 #else 954 /* 955 * For 64-bit kernel, __va can't be used since it would return a linear 956 * mapping address whereas dtb_early_va will be used before 957 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the 958 * kernel is mapped in the linear mapping, that makes no difference. 959 */ 960 dtb_early_va = kernel_mapping_pa_to_va(dtb_pa); 961 #endif 962 963 dtb_early_pa = dtb_pa; 964 } 965 966 /* 967 * MMU is not enabled, the page tables are allocated directly using 968 * early_pmd/pud/p4d and the address returned is the physical one. 969 */ 970 static void __init pt_ops_set_early(void) 971 { 972 pt_ops.alloc_pte = alloc_pte_early; 973 pt_ops.get_pte_virt = get_pte_virt_early; 974 #ifndef __PAGETABLE_PMD_FOLDED 975 pt_ops.alloc_pmd = alloc_pmd_early; 976 pt_ops.get_pmd_virt = get_pmd_virt_early; 977 pt_ops.alloc_pud = alloc_pud_early; 978 pt_ops.get_pud_virt = get_pud_virt_early; 979 pt_ops.alloc_p4d = alloc_p4d_early; 980 pt_ops.get_p4d_virt = get_p4d_virt_early; 981 #endif 982 } 983 984 /* 985 * MMU is enabled but page table setup is not complete yet. 986 * fixmap page table alloc functions must be used as a means to temporarily 987 * map the allocated physical pages since the linear mapping does not exist yet. 988 * 989 * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va, 990 * but it will be used as described above. 991 */ 992 static void __init pt_ops_set_fixmap(void) 993 { 994 pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap); 995 pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap); 996 #ifndef __PAGETABLE_PMD_FOLDED 997 pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap); 998 pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap); 999 pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap); 1000 pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap); 1001 pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap); 1002 pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap); 1003 #endif 1004 } 1005 1006 /* 1007 * MMU is enabled and page table setup is complete, so from now, we can use 1008 * generic page allocation functions to setup page table. 1009 */ 1010 static void __init pt_ops_set_late(void) 1011 { 1012 pt_ops.alloc_pte = alloc_pte_late; 1013 pt_ops.get_pte_virt = get_pte_virt_late; 1014 #ifndef __PAGETABLE_PMD_FOLDED 1015 pt_ops.alloc_pmd = alloc_pmd_late; 1016 pt_ops.get_pmd_virt = get_pmd_virt_late; 1017 pt_ops.alloc_pud = alloc_pud_late; 1018 pt_ops.get_pud_virt = get_pud_virt_late; 1019 pt_ops.alloc_p4d = alloc_p4d_late; 1020 pt_ops.get_p4d_virt = get_p4d_virt_late; 1021 #endif 1022 } 1023 1024 #ifdef CONFIG_RANDOMIZE_BASE 1025 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa); 1026 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa); 1027 1028 static int __init print_nokaslr(char *p) 1029 { 1030 pr_info("Disabled KASLR"); 1031 return 0; 1032 } 1033 early_param("nokaslr", print_nokaslr); 1034 1035 unsigned long kaslr_offset(void) 1036 { 1037 return kernel_map.virt_offset; 1038 } 1039 #endif 1040 1041 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 1042 { 1043 pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd; 1044 1045 #ifdef CONFIG_RANDOMIZE_BASE 1046 if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) { 1047 u64 kaslr_seed = __pi_get_kaslr_seed(dtb_pa); 1048 u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start); 1049 u32 nr_pos; 1050 1051 /* 1052 * Compute the number of positions available: we are limited 1053 * by the early page table that only has one PUD and we must 1054 * be aligned on PMD_SIZE. 1055 */ 1056 nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE; 1057 1058 kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE; 1059 } 1060 #endif 1061 1062 kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset; 1063 1064 #ifdef CONFIG_XIP_KERNEL 1065 #ifdef CONFIG_64BIT 1066 kernel_map.page_offset = PAGE_OFFSET_L3; 1067 #else 1068 kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL); 1069 #endif 1070 kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR; 1071 kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom); 1072 1073 phys_ram_base = CONFIG_PHYS_RAM_BASE; 1074 kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE; 1075 kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata); 1076 1077 kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom; 1078 #else 1079 kernel_map.page_offset = _AC(CONFIG_PAGE_OFFSET, UL); 1080 kernel_map.phys_addr = (uintptr_t)(&_start); 1081 kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr; 1082 #endif 1083 1084 #if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL) 1085 set_satp_mode(dtb_pa); 1086 set_mmap_rnd_bits_max(); 1087 #endif 1088 1089 /* 1090 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem, 1091 * where we have the system memory layout: this allows us to align 1092 * the physical and virtual mappings and then make use of PUD/P4D/PGD 1093 * for the linear mapping. This is only possible because the kernel 1094 * mapping lies outside the linear mapping. 1095 * In 32-bit however, as the kernel resides in the linear mapping, 1096 * setup_vm_final can not change the mapping established here, 1097 * otherwise the same kernel addresses would get mapped to different 1098 * physical addresses (if the start of dram is different from the 1099 * kernel physical address start). 1100 */ 1101 kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ? 1102 0UL : PAGE_OFFSET - kernel_map.phys_addr; 1103 kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr; 1104 1105 /* 1106 * The default maximal physical memory size is KERN_VIRT_SIZE for 32-bit 1107 * kernel, whereas for 64-bit kernel, the end of the virtual address 1108 * space is occupied by the modules/BPF/kernel mappings which reduces 1109 * the available size of the linear mapping. 1110 */ 1111 memory_limit = KERN_VIRT_SIZE - (IS_ENABLED(CONFIG_64BIT) ? SZ_4G : 0); 1112 1113 /* Sanity check alignment and size */ 1114 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 1115 BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0); 1116 1117 #ifdef CONFIG_64BIT 1118 /* 1119 * The last 4K bytes of the addressable memory can not be mapped because 1120 * of IS_ERR_VALUE macro. 1121 */ 1122 BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); 1123 #endif 1124 1125 #ifdef CONFIG_RELOCATABLE 1126 /* 1127 * Early page table uses only one PUD, which makes it possible 1128 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset 1129 * makes the kernel cross over a PUD_SIZE boundary, raise a bug 1130 * since a part of the kernel would not get mapped. 1131 */ 1132 BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size); 1133 relocate_kernel(); 1134 #endif 1135 1136 apply_early_boot_alternatives(); 1137 pt_ops_set_early(); 1138 1139 /* Setup early PGD for fixmap */ 1140 create_pgd_mapping(early_pg_dir, FIXADDR_START, 1141 fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); 1142 1143 #ifndef __PAGETABLE_PMD_FOLDED 1144 /* Setup fixmap P4D and PUD */ 1145 if (pgtable_l5_enabled) 1146 create_p4d_mapping(fixmap_p4d, FIXADDR_START, 1147 (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE); 1148 /* Setup fixmap PUD and PMD */ 1149 if (pgtable_l4_enabled) 1150 create_pud_mapping(fixmap_pud, FIXADDR_START, 1151 (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE); 1152 create_pmd_mapping(fixmap_pmd, FIXADDR_START, 1153 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); 1154 /* Setup trampoline PGD and PMD */ 1155 create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr, 1156 trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE); 1157 if (pgtable_l5_enabled) 1158 create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr, 1159 (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE); 1160 if (pgtable_l4_enabled) 1161 create_pud_mapping(trampoline_pud, kernel_map.virt_addr, 1162 (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE); 1163 #ifdef CONFIG_XIP_KERNEL 1164 create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr, 1165 kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC); 1166 #else 1167 create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr, 1168 kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC); 1169 #endif 1170 #else 1171 /* Setup trampoline PGD */ 1172 create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr, 1173 kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC); 1174 #endif 1175 1176 /* 1177 * Setup early PGD covering entire kernel which will allow 1178 * us to reach paging_init(). We map all memory banks later 1179 * in setup_vm_final() below. 1180 */ 1181 create_kernel_page_table(early_pg_dir, true); 1182 1183 /* Setup early mapping for FDT early scan */ 1184 create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa); 1185 1186 /* 1187 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap 1188 * range can not span multiple pmds. 1189 */ 1190 BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) 1191 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); 1192 1193 #ifndef __PAGETABLE_PMD_FOLDED 1194 /* 1195 * Early ioremap fixmap is already created as it lies within first 2MB 1196 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END 1197 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn 1198 * the user if not. 1199 */ 1200 fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))]; 1201 fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))]; 1202 if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) { 1203 WARN_ON(1); 1204 pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n", 1205 pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd)); 1206 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", 1207 fix_to_virt(FIX_BTMAP_BEGIN)); 1208 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", 1209 fix_to_virt(FIX_BTMAP_END)); 1210 1211 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); 1212 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); 1213 } 1214 #endif 1215 1216 pt_ops_set_fixmap(); 1217 } 1218 1219 static void __init create_linear_mapping_range(phys_addr_t start, 1220 phys_addr_t end, 1221 uintptr_t fixed_map_size) 1222 { 1223 phys_addr_t pa; 1224 uintptr_t va, map_size; 1225 1226 for (pa = start; pa < end; pa += map_size) { 1227 va = (uintptr_t)__va(pa); 1228 map_size = fixed_map_size ? fixed_map_size : 1229 best_map_size(pa, va, end - pa); 1230 1231 create_pgd_mapping(swapper_pg_dir, va, pa, map_size, 1232 pgprot_from_va(va)); 1233 } 1234 } 1235 1236 static void __init create_linear_mapping_page_table(void) 1237 { 1238 phys_addr_t start, end; 1239 phys_addr_t kfence_pool __maybe_unused; 1240 u64 i; 1241 1242 #ifdef CONFIG_STRICT_KERNEL_RWX 1243 phys_addr_t ktext_start = __pa_symbol(_start); 1244 phys_addr_t ktext_size = __init_data_begin - _start; 1245 phys_addr_t krodata_start = __pa_symbol(__start_rodata); 1246 phys_addr_t krodata_size = _data - __start_rodata; 1247 1248 /* Isolate kernel text and rodata so they don't get mapped with a PUD */ 1249 memblock_mark_nomap(ktext_start, ktext_size); 1250 memblock_mark_nomap(krodata_start, krodata_size); 1251 #endif 1252 1253 #ifdef CONFIG_KFENCE 1254 /* 1255 * kfence pool must be backed by PAGE_SIZE mappings, so allocate it 1256 * before we setup the linear mapping so that we avoid using hugepages 1257 * for this region. 1258 */ 1259 kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); 1260 BUG_ON(!kfence_pool); 1261 1262 memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE); 1263 __kfence_pool = __va(kfence_pool); 1264 #endif 1265 1266 /* Map all memory banks in the linear mapping */ 1267 for_each_mem_range(i, &start, &end) { 1268 if (start >= end) 1269 break; 1270 if (start <= __pa(PAGE_OFFSET) && 1271 __pa(PAGE_OFFSET) < end) 1272 start = __pa(PAGE_OFFSET); 1273 if (end >= __pa(PAGE_OFFSET) + memory_limit) 1274 end = __pa(PAGE_OFFSET) + memory_limit; 1275 1276 create_linear_mapping_range(start, end, 0); 1277 } 1278 1279 #ifdef CONFIG_STRICT_KERNEL_RWX 1280 create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0); 1281 create_linear_mapping_range(krodata_start, 1282 krodata_start + krodata_size, 0); 1283 1284 memblock_clear_nomap(ktext_start, ktext_size); 1285 memblock_clear_nomap(krodata_start, krodata_size); 1286 #endif 1287 1288 #ifdef CONFIG_KFENCE 1289 create_linear_mapping_range(kfence_pool, 1290 kfence_pool + KFENCE_POOL_SIZE, 1291 PAGE_SIZE); 1292 1293 memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); 1294 #endif 1295 } 1296 1297 static void __init setup_vm_final(void) 1298 { 1299 /* Setup swapper PGD for fixmap */ 1300 #if !defined(CONFIG_64BIT) 1301 /* 1302 * In 32-bit, the device tree lies in a pgd entry, so it must be copied 1303 * directly in swapper_pg_dir in addition to the pgd entry that points 1304 * to fixmap_pte. 1305 */ 1306 unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT)); 1307 1308 set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]); 1309 #endif 1310 create_pgd_mapping(swapper_pg_dir, FIXADDR_START, 1311 __pa_symbol(fixmap_pgd_next), 1312 PGDIR_SIZE, PAGE_TABLE); 1313 1314 /* Map the linear mapping */ 1315 create_linear_mapping_page_table(); 1316 1317 /* Map the kernel */ 1318 if (IS_ENABLED(CONFIG_64BIT)) 1319 create_kernel_page_table(swapper_pg_dir, false); 1320 1321 #ifdef CONFIG_KASAN 1322 kasan_swapper_init(); 1323 #endif 1324 1325 /* Clear fixmap PTE and PMD mappings */ 1326 clear_fixmap(FIX_PTE); 1327 clear_fixmap(FIX_PMD); 1328 clear_fixmap(FIX_PUD); 1329 clear_fixmap(FIX_P4D); 1330 1331 /* Move to swapper page table */ 1332 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode); 1333 local_flush_tlb_all(); 1334 1335 pt_ops_set_late(); 1336 } 1337 #else 1338 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 1339 { 1340 dtb_early_va = (void *)dtb_pa; 1341 dtb_early_pa = dtb_pa; 1342 } 1343 1344 static inline void setup_vm_final(void) 1345 { 1346 } 1347 #endif /* CONFIG_MMU */ 1348 1349 /* 1350 * reserve_crashkernel() - reserves memory for crash kernel 1351 * 1352 * This function reserves memory area given in "crashkernel=" kernel command 1353 * line parameter. The memory reserved is used by dump capture kernel when 1354 * primary kernel is crashing. 1355 */ 1356 static void __init arch_reserve_crashkernel(void) 1357 { 1358 unsigned long long low_size = 0; 1359 unsigned long long crash_base, crash_size; 1360 char *cmdline = boot_command_line; 1361 bool high = false; 1362 int ret; 1363 1364 if (!IS_ENABLED(CONFIG_CRASH_RESERVE)) 1365 return; 1366 1367 ret = parse_crashkernel(cmdline, memblock_phys_mem_size(), 1368 &crash_size, &crash_base, 1369 &low_size, &high); 1370 if (ret) 1371 return; 1372 1373 reserve_crashkernel_generic(cmdline, crash_size, crash_base, 1374 low_size, high); 1375 } 1376 1377 void __init paging_init(void) 1378 { 1379 setup_bootmem(); 1380 setup_vm_final(); 1381 1382 /* Depend on that Linear Mapping is ready */ 1383 memblock_allow_resize(); 1384 } 1385 1386 void __init misc_mem_init(void) 1387 { 1388 early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); 1389 arch_numa_init(); 1390 sparse_init(); 1391 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1392 /* The entire VMEMMAP region has been populated. Flush TLB for this region */ 1393 local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); 1394 #endif 1395 zone_sizes_init(); 1396 arch_reserve_crashkernel(); 1397 memblock_dump_all(); 1398 } 1399 1400 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1401 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node, 1402 unsigned long addr, unsigned long next) 1403 { 1404 pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL); 1405 } 1406 1407 int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node, 1408 unsigned long addr, unsigned long next) 1409 { 1410 vmemmap_verify((pte_t *)pmdp, node, addr, next); 1411 return 1; 1412 } 1413 1414 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 1415 struct vmem_altmap *altmap) 1416 { 1417 /* 1418 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we 1419 * can't use hugepage mappings for 2-level page table because in case of 1420 * memory hotplug, we are not able to update all the page tables with 1421 * the new PMDs. 1422 */ 1423 return vmemmap_populate_hugepages(start, end, node, NULL); 1424 } 1425 #endif 1426 1427 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) 1428 /* 1429 * Pre-allocates page-table pages for a specific area in the kernel 1430 * page-table. Only the level which needs to be synchronized between 1431 * all page-tables is allocated because the synchronization can be 1432 * expensive. 1433 */ 1434 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end, 1435 const char *area) 1436 { 1437 unsigned long addr; 1438 const char *lvl; 1439 1440 for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) { 1441 pgd_t *pgd = pgd_offset_k(addr); 1442 p4d_t *p4d; 1443 pud_t *pud; 1444 pmd_t *pmd; 1445 1446 lvl = "p4d"; 1447 p4d = p4d_alloc(&init_mm, pgd, addr); 1448 if (!p4d) 1449 goto failed; 1450 1451 if (pgtable_l5_enabled) 1452 continue; 1453 1454 lvl = "pud"; 1455 pud = pud_alloc(&init_mm, p4d, addr); 1456 if (!pud) 1457 goto failed; 1458 1459 if (pgtable_l4_enabled) 1460 continue; 1461 1462 lvl = "pmd"; 1463 pmd = pmd_alloc(&init_mm, pud, addr); 1464 if (!pmd) 1465 goto failed; 1466 } 1467 return; 1468 1469 failed: 1470 /* 1471 * The pages have to be there now or they will be missing in 1472 * process page-tables later. 1473 */ 1474 panic("Failed to pre-allocate %s pages for %s area\n", lvl, area); 1475 } 1476 1477 void __init pgtable_cache_init(void) 1478 { 1479 preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc"); 1480 if (IS_ENABLED(CONFIG_MODULES)) 1481 preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules"); 1482 } 1483 #endif 1484