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 #include <linux/kfence.h> 24 #include <linux/execmem.h> 25 26 #include <asm/alternative.h> 27 #include <asm/fixmap.h> 28 #include <asm/io.h> 29 #include <asm/kasan.h> 30 #include <asm/module.h> 31 #include <asm/numa.h> 32 #include <asm/pgtable.h> 33 #include <asm/sections.h> 34 #include <asm/soc.h> 35 #include <asm/sparsemem.h> 36 #include <asm/tlbflush.h> 37 38 #include "../kernel/head.h" 39 40 u64 new_vmalloc[NR_CPUS / sizeof(u64) + 1]; 41 42 struct kernel_mapping kernel_map __ro_after_init; 43 EXPORT_SYMBOL(kernel_map); 44 45 #ifdef CONFIG_64BIT 46 u64 satp_mode __ro_after_init = SATP_MODE_57; 47 #else 48 u64 satp_mode __ro_after_init = SATP_MODE_32; 49 #endif 50 EXPORT_SYMBOL(satp_mode); 51 52 #ifdef CONFIG_64BIT 53 bool pgtable_l4_enabled __ro_after_init = true; 54 bool pgtable_l5_enabled __ro_after_init = true; 55 EXPORT_SYMBOL(pgtable_l4_enabled); 56 EXPORT_SYMBOL(pgtable_l5_enabled); 57 #endif 58 59 phys_addr_t phys_ram_base __ro_after_init; 60 EXPORT_SYMBOL(phys_ram_base); 61 62 #ifdef CONFIG_SPARSEMEM_VMEMMAP 63 #define VMEMMAP_ADDR_ALIGN max(1ULL << SECTION_SIZE_BITS, \ 64 MAX_FOLIO_VMEMMAP_ALIGN) 65 66 unsigned long vmemmap_start_pfn __ro_after_init; 67 EXPORT_SYMBOL(vmemmap_start_pfn); 68 #endif 69 70 extern char _start[]; 71 void *_dtb_early_va __initdata; 72 uintptr_t _dtb_early_pa __initdata; 73 74 phys_addr_t dma32_phys_limit __initdata; 75 76 void __init arch_zone_limits_init(unsigned long *max_zone_pfns) 77 { 78 #ifdef CONFIG_ZONE_DMA32 79 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit); 80 #endif 81 max_zone_pfns[ZONE_NORMAL] = max_low_pfn; 82 } 83 84 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM) 85 86 #define LOG2_SZ_1K ilog2(SZ_1K) 87 #define LOG2_SZ_1M ilog2(SZ_1M) 88 #define LOG2_SZ_1G ilog2(SZ_1G) 89 #define LOG2_SZ_1T ilog2(SZ_1T) 90 91 static inline void print_mlk(char *name, unsigned long b, unsigned long t) 92 { 93 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld kB)\n", name, b, t, 94 (((t) - (b)) >> LOG2_SZ_1K)); 95 } 96 97 static inline void print_mlm(char *name, unsigned long b, unsigned long t) 98 { 99 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld MB)\n", name, b, t, 100 (((t) - (b)) >> LOG2_SZ_1M)); 101 } 102 103 static inline void print_mlg(char *name, unsigned long b, unsigned long t) 104 { 105 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld GB)\n", name, b, t, 106 (((t) - (b)) >> LOG2_SZ_1G)); 107 } 108 109 #ifdef CONFIG_64BIT 110 static inline void print_mlt(char *name, unsigned long b, unsigned long t) 111 { 112 pr_notice("%12s : 0x%08lx - 0x%08lx (%4ld TB)\n", name, b, t, 113 (((t) - (b)) >> LOG2_SZ_1T)); 114 } 115 #else 116 #define print_mlt(n, b, t) do {} while (0) 117 #endif 118 119 static inline void print_ml(char *name, unsigned long b, unsigned long t) 120 { 121 unsigned long diff = t - b; 122 123 if (IS_ENABLED(CONFIG_64BIT) && (diff >> LOG2_SZ_1T) >= 10) 124 print_mlt(name, b, t); 125 else if ((diff >> LOG2_SZ_1G) >= 10) 126 print_mlg(name, b, t); 127 else if ((diff >> LOG2_SZ_1M) >= 10) 128 print_mlm(name, b, t); 129 else 130 print_mlk(name, b, t); 131 } 132 133 static void __init print_vm_layout(void) 134 { 135 pr_notice("Virtual kernel memory layout:\n"); 136 print_ml("fixmap", (unsigned long)FIXADDR_START, 137 (unsigned long)FIXADDR_TOP); 138 print_ml("pci io", (unsigned long)PCI_IO_START, 139 (unsigned long)PCI_IO_END); 140 print_ml("vmemmap", (unsigned long)VMEMMAP_START, 141 (unsigned long)VMEMMAP_END); 142 print_ml("vmalloc", (unsigned long)VMALLOC_START, 143 (unsigned long)VMALLOC_END); 144 #ifdef CONFIG_64BIT 145 print_ml("modules", (unsigned long)MODULES_VADDR, 146 (unsigned long)MODULES_END); 147 #endif 148 print_ml("lowmem", (unsigned long)PAGE_OFFSET, 149 (unsigned long)high_memory); 150 if (IS_ENABLED(CONFIG_64BIT)) { 151 #ifdef CONFIG_KASAN 152 print_ml("kasan", KASAN_SHADOW_START, KASAN_SHADOW_END); 153 #endif 154 155 print_ml("kernel", (unsigned long)kernel_map.virt_addr, 156 (unsigned long)ADDRESS_SPACE_END); 157 } 158 } 159 #else 160 static void print_vm_layout(void) { } 161 #endif /* CONFIG_DEBUG_VM */ 162 163 void __init arch_mm_preinit(void) 164 { 165 bool swiotlb = max_pfn > PFN_DOWN(dma32_phys_limit); 166 #ifdef CONFIG_FLATMEM 167 BUG_ON(!mem_map); 168 #endif /* CONFIG_FLATMEM */ 169 170 if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb && 171 dma_cache_alignment != 1) { 172 /* 173 * If no bouncing needed for ZONE_DMA, allocate 1MB swiotlb 174 * buffer per 1GB of RAM for kmalloc() bouncing on 175 * non-coherent platforms. 176 */ 177 unsigned long size = 178 DIV_ROUND_UP(memblock_phys_mem_size(), 1024); 179 swiotlb_adjust_size(min(swiotlb_size_or_default(), size)); 180 swiotlb = true; 181 } 182 183 swiotlb_init(swiotlb, SWIOTLB_VERBOSE); 184 185 print_vm_layout(); 186 } 187 188 /* Limit the memory size via mem. */ 189 static phys_addr_t memory_limit; 190 191 static int __init early_mem(char *p) 192 { 193 u64 size; 194 195 if (!p) 196 return 1; 197 198 size = memparse(p, &p) & PAGE_MASK; 199 memory_limit = min_t(u64, size, memory_limit); 200 201 pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20); 202 203 return 0; 204 } 205 early_param("mem", early_mem); 206 207 static void __init setup_bootmem(void) 208 { 209 phys_addr_t vmlinux_end = __pa_symbol(&_end); 210 phys_addr_t max_mapped_addr; 211 phys_addr_t phys_ram_end, vmlinux_start; 212 213 vmlinux_start = __pa_symbol(&_start); 214 215 memblock_enforce_memory_limit(memory_limit); 216 217 /* 218 * Make sure we align the reservation on PMD_SIZE since we will 219 * map the kernel in the linear mapping as read-only: we do not want 220 * any allocation to happen between _end and the next pmd aligned page. 221 */ 222 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) 223 vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK; 224 /* 225 * Reserve from the start of the kernel to the end of the kernel 226 */ 227 memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); 228 229 /* 230 * Make sure we align the start of the memory on a PMD boundary so that 231 * at worst, we map the linear mapping with PMD mappings. 232 */ 233 phys_ram_base = memblock_start_of_DRAM() & PMD_MASK; 234 #ifdef CONFIG_SPARSEMEM_VMEMMAP 235 vmemmap_start_pfn = round_down(phys_ram_base, VMEMMAP_ADDR_ALIGN) >> PAGE_SHIFT; 236 #endif 237 238 /* 239 * In 64-bit, any use of __va/__pa before this point is wrong as we 240 * did not know the start of DRAM before. 241 */ 242 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) 243 kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base; 244 245 /* 246 * The size of the linear page mapping may restrict the amount of 247 * usable RAM. 248 */ 249 if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) { 250 max_mapped_addr = __pa(PAGE_OFFSET) + KERN_VIRT_SIZE; 251 if (memblock_end_of_DRAM() > max_mapped_addr) { 252 memblock_cap_memory_range(phys_ram_base, 253 max_mapped_addr - phys_ram_base); 254 pr_warn("Physical memory overflows the linear mapping size: region above %pa removed", 255 &max_mapped_addr); 256 } 257 } 258 259 /* 260 * Reserve physical address space that would be mapped to virtual 261 * addresses greater than (void *)(-PAGE_SIZE) because: 262 * - This memory would overlap with ERR_PTR 263 * - This memory belongs to high memory, which is not supported 264 * 265 * This is not applicable to 64-bit kernel, because virtual addresses 266 * after (void *)(-PAGE_SIZE) are not linearly mapped: they are 267 * occupied by kernel mapping. Also it is unrealistic for high memory 268 * to exist on 64-bit platforms. 269 */ 270 if (!IS_ENABLED(CONFIG_64BIT)) { 271 max_mapped_addr = __va_to_pa_nodebug(-PAGE_SIZE); 272 memblock_reserve(max_mapped_addr, (phys_addr_t)-max_mapped_addr); 273 } 274 275 phys_ram_end = memblock_end_of_DRAM(); 276 min_low_pfn = PFN_UP(phys_ram_base); 277 max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end); 278 279 dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn)); 280 281 reserve_initrd_mem(); 282 283 /* 284 * No allocation should be done before reserving the memory as defined 285 * in the device tree, otherwise the allocation could end up in a 286 * reserved region. 287 */ 288 early_init_fdt_scan_reserved_mem(); 289 290 /* 291 * If DTB is built in, no need to reserve its memblock. 292 * Otherwise, do reserve it but avoid using 293 * early_init_fdt_reserve_self() since __pa() does 294 * not work for DTB pointers that are fixmap addresses 295 */ 296 if (!IS_ENABLED(CONFIG_BUILTIN_DTB)) 297 memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va)); 298 299 dma_contiguous_reserve(dma32_phys_limit); 300 } 301 302 #ifdef CONFIG_RELOCATABLE 303 extern unsigned long __rela_dyn_start, __rela_dyn_end; 304 305 static void __init relocate_kernel(void) 306 { 307 Elf_Rela *rela = (Elf_Rela *)&__rela_dyn_start; 308 /* 309 * This holds the offset between the linked virtual address and the 310 * relocated virtual address. 311 */ 312 uintptr_t reloc_offset = kernel_map.virt_addr - KERNEL_LINK_ADDR; 313 /* 314 * This holds the offset between kernel linked virtual address and 315 * physical address. 316 */ 317 uintptr_t va_kernel_link_pa_offset = KERNEL_LINK_ADDR - kernel_map.phys_addr; 318 319 for ( ; rela < (Elf_Rela *)&__rela_dyn_end; rela++) { 320 Elf_Addr addr = (rela->r_offset - va_kernel_link_pa_offset); 321 Elf_Addr relocated_addr = rela->r_addend; 322 323 if (rela->r_info != R_RISCV_RELATIVE) 324 continue; 325 326 /* 327 * Make sure to not relocate vdso symbols like rt_sigreturn 328 * which are linked from the address 0 in vmlinux since 329 * vdso symbol addresses are actually used as an offset from 330 * mm->context.vdso in VDSO_OFFSET macro. 331 */ 332 if (relocated_addr >= KERNEL_LINK_ADDR) 333 relocated_addr += reloc_offset; 334 335 *(Elf_Addr *)addr = relocated_addr; 336 } 337 } 338 #endif /* CONFIG_RELOCATABLE */ 339 340 #ifdef CONFIG_MMU 341 struct pt_alloc_ops pt_ops __meminitdata; 342 343 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 344 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; 345 static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; 346 347 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); 348 349 static const pgprot_t protection_map[16] = { 350 [VM_NONE] = PAGE_NONE, 351 [VM_READ] = PAGE_READ, 352 [VM_WRITE] = PAGE_SHADOWSTACK, 353 [VM_WRITE | VM_READ] = PAGE_COPY, 354 [VM_EXEC] = PAGE_EXEC, 355 [VM_EXEC | VM_READ] = PAGE_READ_EXEC, 356 [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC, 357 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC, 358 [VM_SHARED] = PAGE_NONE, 359 [VM_SHARED | VM_READ] = PAGE_READ, 360 [VM_SHARED | VM_WRITE] = PAGE_SHARED, 361 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, 362 [VM_SHARED | VM_EXEC] = PAGE_EXEC, 363 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READ_EXEC, 364 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC, 365 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC 366 }; 367 DECLARE_VM_GET_PAGE_PROT 368 369 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) 370 { 371 unsigned long addr = __fix_to_virt(idx); 372 pte_t *ptep; 373 374 BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); 375 376 ptep = &fixmap_pte[pte_index(addr)]; 377 378 if (pgprot_val(prot)) 379 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); 380 else 381 pte_clear(&init_mm, addr, ptep); 382 local_flush_tlb_page(addr); 383 } 384 385 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa) 386 { 387 return (pte_t *)((uintptr_t)pa); 388 } 389 390 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa) 391 { 392 clear_fixmap(FIX_PTE); 393 return (pte_t *)set_fixmap_offset(FIX_PTE, pa); 394 } 395 396 static inline pte_t *__meminit get_pte_virt_late(phys_addr_t pa) 397 { 398 return (pte_t *) __va(pa); 399 } 400 401 static inline phys_addr_t __init alloc_pte_early(uintptr_t va) 402 { 403 /* 404 * We only create PMD or PGD early mappings so we 405 * should never reach here with MMU disabled. 406 */ 407 BUG(); 408 } 409 410 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va) 411 { 412 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 413 } 414 415 static phys_addr_t __meminit alloc_pte_late(uintptr_t va) 416 { 417 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0); 418 419 /* 420 * We do not know which mm the PTE page is associated to at this point. 421 * Passing NULL to the ctor is the safe option, though it may result 422 * in unnecessary work (e.g. initialising the ptlock for init_mm). 423 */ 424 BUG_ON(!ptdesc || !pagetable_pte_ctor(NULL, ptdesc)); 425 return __pa((pte_t *)ptdesc_address(ptdesc)); 426 } 427 428 static void __meminit create_pte_mapping(pte_t *ptep, uintptr_t va, phys_addr_t pa, phys_addr_t sz, 429 pgprot_t prot) 430 { 431 uintptr_t pte_idx = pte_index(va); 432 433 BUG_ON(sz != PAGE_SIZE); 434 435 if (pte_none(ptep[pte_idx])) 436 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot); 437 } 438 439 #ifndef __PAGETABLE_PMD_FOLDED 440 441 static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss; 442 static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; 443 static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE); 444 445 static p4d_t trampoline_p4d[PTRS_PER_P4D] __page_aligned_bss; 446 static p4d_t fixmap_p4d[PTRS_PER_P4D] __page_aligned_bss; 447 static p4d_t early_p4d[PTRS_PER_P4D] __initdata __aligned(PAGE_SIZE); 448 449 static pud_t trampoline_pud[PTRS_PER_PUD] __page_aligned_bss; 450 static pud_t fixmap_pud[PTRS_PER_PUD] __page_aligned_bss; 451 static pud_t early_pud[PTRS_PER_PUD] __initdata __aligned(PAGE_SIZE); 452 453 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa) 454 { 455 /* Before MMU is enabled */ 456 return (pmd_t *)((uintptr_t)pa); 457 } 458 459 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa) 460 { 461 clear_fixmap(FIX_PMD); 462 return (pmd_t *)set_fixmap_offset(FIX_PMD, pa); 463 } 464 465 static pmd_t *__meminit get_pmd_virt_late(phys_addr_t pa) 466 { 467 return (pmd_t *) __va(pa); 468 } 469 470 static phys_addr_t __init alloc_pmd_early(uintptr_t va) 471 { 472 BUG_ON((va - kernel_map.virt_addr) >> PUD_SHIFT); 473 474 return (uintptr_t)early_pmd; 475 } 476 477 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va) 478 { 479 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 480 } 481 482 static phys_addr_t __meminit alloc_pmd_late(uintptr_t va) 483 { 484 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0); 485 486 /* See comment in alloc_pte_late() regarding NULL passed the ctor */ 487 BUG_ON(!ptdesc || !pagetable_pmd_ctor(NULL, ptdesc)); 488 return __pa((pmd_t *)ptdesc_address(ptdesc)); 489 } 490 491 static void __meminit create_pmd_mapping(pmd_t *pmdp, 492 uintptr_t va, phys_addr_t pa, 493 phys_addr_t sz, pgprot_t prot) 494 { 495 pte_t *ptep; 496 phys_addr_t pte_phys; 497 uintptr_t pmd_idx = pmd_index(va); 498 499 if (sz == PMD_SIZE) { 500 if (pmd_none(pmdp[pmd_idx])) 501 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot); 502 return; 503 } 504 505 if (pmd_none(pmdp[pmd_idx])) { 506 pte_phys = pt_ops.alloc_pte(va); 507 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE); 508 ptep = pt_ops.get_pte_virt(pte_phys); 509 memset(ptep, 0, PAGE_SIZE); 510 } else { 511 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx])); 512 ptep = pt_ops.get_pte_virt(pte_phys); 513 } 514 515 create_pte_mapping(ptep, va, pa, sz, prot); 516 } 517 518 static pud_t *__init get_pud_virt_early(phys_addr_t pa) 519 { 520 return (pud_t *)((uintptr_t)pa); 521 } 522 523 static pud_t *__init get_pud_virt_fixmap(phys_addr_t pa) 524 { 525 clear_fixmap(FIX_PUD); 526 return (pud_t *)set_fixmap_offset(FIX_PUD, pa); 527 } 528 529 static pud_t *__meminit get_pud_virt_late(phys_addr_t pa) 530 { 531 return (pud_t *)__va(pa); 532 } 533 534 static phys_addr_t __init alloc_pud_early(uintptr_t va) 535 { 536 /* Only one PUD is available for early mapping */ 537 BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT); 538 539 return (uintptr_t)early_pud; 540 } 541 542 static phys_addr_t __init alloc_pud_fixmap(uintptr_t va) 543 { 544 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 545 } 546 547 static phys_addr_t __meminit alloc_pud_late(uintptr_t va) 548 { 549 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0); 550 551 BUG_ON(!ptdesc); 552 pagetable_pud_ctor(ptdesc); 553 return __pa((pud_t *)ptdesc_address(ptdesc)); 554 } 555 556 static p4d_t *__init get_p4d_virt_early(phys_addr_t pa) 557 { 558 return (p4d_t *)((uintptr_t)pa); 559 } 560 561 static p4d_t *__init get_p4d_virt_fixmap(phys_addr_t pa) 562 { 563 clear_fixmap(FIX_P4D); 564 return (p4d_t *)set_fixmap_offset(FIX_P4D, pa); 565 } 566 567 static p4d_t *__meminit get_p4d_virt_late(phys_addr_t pa) 568 { 569 return (p4d_t *)__va(pa); 570 } 571 572 static phys_addr_t __init alloc_p4d_early(uintptr_t va) 573 { 574 /* Only one P4D is available for early mapping */ 575 BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT); 576 577 return (uintptr_t)early_p4d; 578 } 579 580 static phys_addr_t __init alloc_p4d_fixmap(uintptr_t va) 581 { 582 return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE); 583 } 584 585 static phys_addr_t __meminit alloc_p4d_late(uintptr_t va) 586 { 587 struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL, 0); 588 589 BUG_ON(!ptdesc); 590 pagetable_p4d_ctor(ptdesc); 591 return __pa((p4d_t *)ptdesc_address(ptdesc)); 592 } 593 594 static void __meminit create_pud_mapping(pud_t *pudp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, 595 pgprot_t prot) 596 { 597 pmd_t *nextp; 598 phys_addr_t next_phys; 599 uintptr_t pud_index = pud_index(va); 600 601 if (sz == PUD_SIZE) { 602 if (pud_val(pudp[pud_index]) == 0) 603 pudp[pud_index] = pfn_pud(PFN_DOWN(pa), prot); 604 return; 605 } 606 607 if (pud_val(pudp[pud_index]) == 0) { 608 next_phys = pt_ops.alloc_pmd(va); 609 pudp[pud_index] = pfn_pud(PFN_DOWN(next_phys), PAGE_TABLE); 610 nextp = pt_ops.get_pmd_virt(next_phys); 611 memset(nextp, 0, PAGE_SIZE); 612 } else { 613 next_phys = PFN_PHYS(_pud_pfn(pudp[pud_index])); 614 nextp = pt_ops.get_pmd_virt(next_phys); 615 } 616 617 create_pmd_mapping(nextp, va, pa, sz, prot); 618 } 619 620 static void __meminit create_p4d_mapping(p4d_t *p4dp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, 621 pgprot_t prot) 622 { 623 pud_t *nextp; 624 phys_addr_t next_phys; 625 uintptr_t p4d_index = p4d_index(va); 626 627 if (sz == P4D_SIZE) { 628 if (p4d_val(p4dp[p4d_index]) == 0) 629 p4dp[p4d_index] = pfn_p4d(PFN_DOWN(pa), prot); 630 return; 631 } 632 633 if (p4d_val(p4dp[p4d_index]) == 0) { 634 next_phys = pt_ops.alloc_pud(va); 635 p4dp[p4d_index] = pfn_p4d(PFN_DOWN(next_phys), PAGE_TABLE); 636 nextp = pt_ops.get_pud_virt(next_phys); 637 memset(nextp, 0, PAGE_SIZE); 638 } else { 639 next_phys = PFN_PHYS(_p4d_pfn(p4dp[p4d_index])); 640 nextp = pt_ops.get_pud_virt(next_phys); 641 } 642 643 create_pud_mapping(nextp, va, pa, sz, prot); 644 } 645 646 #define pgd_next_t p4d_t 647 #define alloc_pgd_next(__va) (pgtable_l5_enabled ? \ 648 pt_ops.alloc_p4d(__va) : (pgtable_l4_enabled ? \ 649 pt_ops.alloc_pud(__va) : pt_ops.alloc_pmd(__va))) 650 #define get_pgd_next_virt(__pa) (pgtable_l5_enabled ? \ 651 pt_ops.get_p4d_virt(__pa) : (pgd_next_t *)(pgtable_l4_enabled ? \ 652 pt_ops.get_pud_virt(__pa) : (pud_t *)pt_ops.get_pmd_virt(__pa))) 653 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 654 (pgtable_l5_enabled ? \ 655 create_p4d_mapping(__nextp, __va, __pa, __sz, __prot) : \ 656 (pgtable_l4_enabled ? \ 657 create_pud_mapping((pud_t *)__nextp, __va, __pa, __sz, __prot) : \ 658 create_pmd_mapping((pmd_t *)__nextp, __va, __pa, __sz, __prot))) 659 #define fixmap_pgd_next (pgtable_l5_enabled ? \ 660 (uintptr_t)fixmap_p4d : (pgtable_l4_enabled ? \ 661 (uintptr_t)fixmap_pud : (uintptr_t)fixmap_pmd)) 662 #define trampoline_pgd_next (pgtable_l5_enabled ? \ 663 (uintptr_t)trampoline_p4d : (pgtable_l4_enabled ? \ 664 (uintptr_t)trampoline_pud : (uintptr_t)trampoline_pmd)) 665 #else 666 #define pgd_next_t pte_t 667 #define alloc_pgd_next(__va) pt_ops.alloc_pte(__va) 668 #define get_pgd_next_virt(__pa) pt_ops.get_pte_virt(__pa) 669 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot) \ 670 create_pte_mapping(__nextp, __va, __pa, __sz, __prot) 671 #define fixmap_pgd_next ((uintptr_t)fixmap_pte) 672 #define create_p4d_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) 673 #define create_pud_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) 674 #define create_pmd_mapping(__pmdp, __va, __pa, __sz, __prot) do {} while(0) 675 #endif /* __PAGETABLE_PMD_FOLDED */ 676 677 void __meminit create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, 678 pgprot_t prot) 679 { 680 pgd_next_t *nextp; 681 phys_addr_t next_phys; 682 uintptr_t pgd_idx = pgd_index(va); 683 684 if (sz == PGDIR_SIZE) { 685 if (pgd_val(pgdp[pgd_idx]) == 0) 686 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot); 687 return; 688 } 689 690 if (pgd_val(pgdp[pgd_idx]) == 0) { 691 next_phys = alloc_pgd_next(va); 692 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE); 693 nextp = get_pgd_next_virt(next_phys); 694 memset(nextp, 0, PAGE_SIZE); 695 } else { 696 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx])); 697 nextp = get_pgd_next_virt(next_phys); 698 } 699 700 create_pgd_next_mapping(nextp, va, pa, sz, prot); 701 } 702 703 static uintptr_t __meminit best_map_size(phys_addr_t pa, uintptr_t va, phys_addr_t size) 704 { 705 if (debug_pagealloc_enabled()) 706 return PAGE_SIZE; 707 708 if (pgtable_l5_enabled && 709 !(pa & (P4D_SIZE - 1)) && !(va & (P4D_SIZE - 1)) && size >= P4D_SIZE) 710 return P4D_SIZE; 711 712 if (pgtable_l4_enabled && 713 !(pa & (PUD_SIZE - 1)) && !(va & (PUD_SIZE - 1)) && size >= PUD_SIZE) 714 return PUD_SIZE; 715 716 if (IS_ENABLED(CONFIG_64BIT) && 717 !(pa & (PMD_SIZE - 1)) && !(va & (PMD_SIZE - 1)) && size >= PMD_SIZE) 718 return PMD_SIZE; 719 720 return PAGE_SIZE; 721 } 722 723 #ifdef CONFIG_STRICT_KERNEL_RWX 724 static __meminit pgprot_t pgprot_from_va(uintptr_t va) 725 { 726 if (is_va_kernel_text(va)) 727 return PAGE_KERNEL_READ_EXEC; 728 729 /* 730 * In 64-bit kernel, the kernel mapping is outside the linear mapping so 731 * we must protect its linear mapping alias from being executed and 732 * written. 733 * And rodata section is marked readonly in mark_rodata_ro. 734 */ 735 if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va)) 736 return PAGE_KERNEL_READ; 737 738 return PAGE_KERNEL; 739 } 740 741 void mark_rodata_ro(void) 742 { 743 set_kernel_memory(__start_rodata, _data, set_memory_ro); 744 if (IS_ENABLED(CONFIG_64BIT)) 745 set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data), 746 set_memory_ro); 747 } 748 #else 749 static __meminit pgprot_t pgprot_from_va(uintptr_t va) 750 { 751 if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va)) 752 return PAGE_KERNEL; 753 754 return PAGE_KERNEL_EXEC; 755 } 756 #endif /* CONFIG_STRICT_KERNEL_RWX */ 757 758 #if defined(CONFIG_64BIT) 759 u64 __pi_set_satp_mode_from_cmdline(uintptr_t dtb_pa); 760 u64 __pi_set_satp_mode_from_fdt(uintptr_t dtb_pa); 761 762 static void __init disable_pgtable_l5(void) 763 { 764 pgtable_l5_enabled = false; 765 kernel_map.page_offset = PAGE_OFFSET_L4; 766 satp_mode = SATP_MODE_48; 767 } 768 769 static void __init disable_pgtable_l4(void) 770 { 771 pgtable_l4_enabled = false; 772 kernel_map.page_offset = PAGE_OFFSET_L3; 773 satp_mode = SATP_MODE_39; 774 } 775 776 static int __init print_no4lvl(char *p) 777 { 778 pr_info("Disabled 4-level and 5-level paging"); 779 return 0; 780 } 781 early_param("no4lvl", print_no4lvl); 782 783 static int __init print_no5lvl(char *p) 784 { 785 pr_info("Disabled 5-level paging"); 786 return 0; 787 } 788 early_param("no5lvl", print_no5lvl); 789 790 static void __init set_mmap_rnd_bits_max(void) 791 { 792 mmap_rnd_bits_max = MMAP_VA_BITS - PAGE_SHIFT - 3; 793 } 794 795 static bool __init is_vaddr_valid(unsigned long va) 796 { 797 unsigned long up = 0; 798 799 switch (satp_mode) { 800 case SATP_MODE_39: 801 up = 1UL << 38; 802 break; 803 case SATP_MODE_48: 804 up = 1UL << 47; 805 break; 806 case SATP_MODE_57: 807 up = 1UL << 56; 808 break; 809 default: 810 return false; 811 } 812 813 return (va < up) || (va >= (ULONG_MAX - up + 1)); 814 } 815 816 /* 817 * There is a simple way to determine if 4-level is supported by the 818 * underlying hardware: establish 1:1 mapping in 4-level page table mode 819 * then read SATP to see if the configuration was taken into account 820 * meaning sv48 is supported. 821 * The maximum SATP mode is limited by both the command line and the "mmu-type" 822 * property in the device tree, since some platforms may hang if an unsupported 823 * SATP mode is attempted. 824 */ 825 static __init void set_satp_mode(uintptr_t dtb_pa) 826 { 827 u64 identity_satp, hw_satp; 828 uintptr_t set_satp_mode_pmd = ((unsigned long)set_satp_mode) & PMD_MASK; 829 u64 satp_mode_limit = min_not_zero(__pi_set_satp_mode_from_cmdline(dtb_pa), 830 __pi_set_satp_mode_from_fdt(dtb_pa)); 831 832 kernel_map.page_offset = PAGE_OFFSET_L5; 833 834 if (satp_mode_limit == SATP_MODE_48) { 835 disable_pgtable_l5(); 836 } else if (satp_mode_limit == SATP_MODE_39) { 837 disable_pgtable_l5(); 838 disable_pgtable_l4(); 839 return; 840 } 841 842 create_p4d_mapping(early_p4d, 843 set_satp_mode_pmd, (uintptr_t)early_pud, 844 P4D_SIZE, PAGE_TABLE); 845 create_pud_mapping(early_pud, 846 set_satp_mode_pmd, (uintptr_t)early_pmd, 847 PUD_SIZE, PAGE_TABLE); 848 /* Handle the case where set_satp_mode straddles 2 PMDs */ 849 create_pmd_mapping(early_pmd, 850 set_satp_mode_pmd, set_satp_mode_pmd, 851 PMD_SIZE, PAGE_KERNEL_EXEC); 852 create_pmd_mapping(early_pmd, 853 set_satp_mode_pmd + PMD_SIZE, 854 set_satp_mode_pmd + PMD_SIZE, 855 PMD_SIZE, PAGE_KERNEL_EXEC); 856 retry: 857 if (!is_vaddr_valid(set_satp_mode_pmd)) 858 goto out; 859 860 create_pgd_mapping(early_pg_dir, 861 set_satp_mode_pmd, 862 pgtable_l5_enabled ? 863 (uintptr_t)early_p4d : (uintptr_t)early_pud, 864 PGDIR_SIZE, PAGE_TABLE); 865 866 identity_satp = PFN_DOWN((uintptr_t)&early_pg_dir) | satp_mode; 867 868 local_flush_tlb_all(); 869 csr_write(CSR_SATP, identity_satp); 870 hw_satp = csr_swap(CSR_SATP, 0ULL); 871 local_flush_tlb_all(); 872 873 if (hw_satp != identity_satp) { 874 if (pgtable_l5_enabled) { 875 disable_pgtable_l5(); 876 memset(early_pg_dir, 0, PAGE_SIZE); 877 goto retry; 878 } 879 disable_pgtable_l4(); 880 } 881 882 out: 883 memset(early_pg_dir, 0, PAGE_SIZE); 884 memset(early_p4d, 0, PAGE_SIZE); 885 memset(early_pud, 0, PAGE_SIZE); 886 memset(early_pmd, 0, PAGE_SIZE); 887 } 888 #endif 889 890 /* 891 * setup_vm() is called from head.S with MMU-off. 892 * 893 * Following requirements should be honoured for setup_vm() to work 894 * correctly: 895 * 1) It should use PC-relative addressing for accessing kernel symbols. 896 * To achieve this we always use GCC cmodel=medany. 897 * 2) The compiler instrumentation for FTRACE will not work for setup_vm() 898 * so disable compiler instrumentation when FTRACE is enabled. 899 * 900 * Currently, the above requirements are honoured by using custom CFLAGS 901 * for init.o in mm/Makefile. 902 */ 903 904 #ifndef __riscv_cmodel_medany 905 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing." 906 #endif 907 908 static void __init create_kernel_page_table(pgd_t *pgdir, bool early) 909 { 910 uintptr_t va, end_va; 911 912 end_va = kernel_map.virt_addr + kernel_map.size; 913 for (va = kernel_map.virt_addr; va < end_va; va += PMD_SIZE) 914 create_pgd_mapping(pgdir, va, 915 kernel_map.phys_addr + (va - kernel_map.virt_addr), 916 PMD_SIZE, 917 early ? 918 PAGE_KERNEL_EXEC : pgprot_from_va(va)); 919 } 920 921 /* 922 * Setup a 4MB mapping that encompasses the device tree: for 64-bit kernel, 923 * this means 2 PMD entries whereas for 32-bit kernel, this is only 1 PGDIR 924 * entry. 925 */ 926 static void __init create_fdt_early_page_table(uintptr_t fix_fdt_va, 927 uintptr_t dtb_pa) 928 { 929 #ifndef CONFIG_BUILTIN_DTB 930 uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1); 931 932 /* Make sure the fdt fixmap address is always aligned on PMD size */ 933 BUILD_BUG_ON(FIX_FDT % (PMD_SIZE / PAGE_SIZE)); 934 935 /* In 32-bit only, the fdt lies in its own PGD */ 936 if (!IS_ENABLED(CONFIG_64BIT)) { 937 create_pgd_mapping(early_pg_dir, fix_fdt_va, 938 pa, MAX_FDT_SIZE, PAGE_KERNEL); 939 } else { 940 create_pmd_mapping(fixmap_pmd, fix_fdt_va, 941 pa, PMD_SIZE, PAGE_KERNEL); 942 create_pmd_mapping(fixmap_pmd, fix_fdt_va + PMD_SIZE, 943 pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL); 944 } 945 946 dtb_early_va = (void *)fix_fdt_va + (dtb_pa & (PMD_SIZE - 1)); 947 #else 948 /* 949 * For 64-bit kernel, __va can't be used since it would return a linear 950 * mapping address whereas dtb_early_va will be used before 951 * setup_vm_final installs the linear mapping. For 32-bit kernel, as the 952 * kernel is mapped in the linear mapping, that makes no difference. 953 */ 954 dtb_early_va = kernel_mapping_pa_to_va(dtb_pa); 955 #endif 956 957 dtb_early_pa = dtb_pa; 958 } 959 960 /* 961 * MMU is not enabled, the page tables are allocated directly using 962 * early_pmd/pud/p4d and the address returned is the physical one. 963 */ 964 static void __init pt_ops_set_early(void) 965 { 966 pt_ops.alloc_pte = alloc_pte_early; 967 pt_ops.get_pte_virt = get_pte_virt_early; 968 #ifndef __PAGETABLE_PMD_FOLDED 969 pt_ops.alloc_pmd = alloc_pmd_early; 970 pt_ops.get_pmd_virt = get_pmd_virt_early; 971 pt_ops.alloc_pud = alloc_pud_early; 972 pt_ops.get_pud_virt = get_pud_virt_early; 973 pt_ops.alloc_p4d = alloc_p4d_early; 974 pt_ops.get_p4d_virt = get_p4d_virt_early; 975 #endif 976 } 977 978 /* 979 * MMU is enabled but page table setup is not complete yet. 980 * fixmap page table alloc functions must be used as a means to temporarily 981 * map the allocated physical pages since the linear mapping does not exist yet. 982 * 983 * Note that this is called with MMU disabled, hence kernel_mapping_pa_to_va, 984 * but it will be used as described above. 985 */ 986 static void __init pt_ops_set_fixmap(void) 987 { 988 pt_ops.alloc_pte = kernel_mapping_pa_to_va(alloc_pte_fixmap); 989 pt_ops.get_pte_virt = kernel_mapping_pa_to_va(get_pte_virt_fixmap); 990 #ifndef __PAGETABLE_PMD_FOLDED 991 pt_ops.alloc_pmd = kernel_mapping_pa_to_va(alloc_pmd_fixmap); 992 pt_ops.get_pmd_virt = kernel_mapping_pa_to_va(get_pmd_virt_fixmap); 993 pt_ops.alloc_pud = kernel_mapping_pa_to_va(alloc_pud_fixmap); 994 pt_ops.get_pud_virt = kernel_mapping_pa_to_va(get_pud_virt_fixmap); 995 pt_ops.alloc_p4d = kernel_mapping_pa_to_va(alloc_p4d_fixmap); 996 pt_ops.get_p4d_virt = kernel_mapping_pa_to_va(get_p4d_virt_fixmap); 997 #endif 998 } 999 1000 /* 1001 * MMU is enabled and page table setup is complete, so from now, we can use 1002 * generic page allocation functions to setup page table. 1003 */ 1004 static void __init pt_ops_set_late(void) 1005 { 1006 pt_ops.alloc_pte = alloc_pte_late; 1007 pt_ops.get_pte_virt = get_pte_virt_late; 1008 #ifndef __PAGETABLE_PMD_FOLDED 1009 pt_ops.alloc_pmd = alloc_pmd_late; 1010 pt_ops.get_pmd_virt = get_pmd_virt_late; 1011 pt_ops.alloc_pud = alloc_pud_late; 1012 pt_ops.get_pud_virt = get_pud_virt_late; 1013 pt_ops.alloc_p4d = alloc_p4d_late; 1014 pt_ops.get_p4d_virt = get_p4d_virt_late; 1015 #endif 1016 } 1017 1018 #ifdef CONFIG_RANDOMIZE_BASE 1019 extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa); 1020 extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa); 1021 extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa); 1022 1023 static int __init print_nokaslr(char *p) 1024 { 1025 pr_info("Disabled KASLR"); 1026 return 0; 1027 } 1028 early_param("nokaslr", print_nokaslr); 1029 #endif 1030 1031 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 1032 { 1033 pmd_t __maybe_unused fix_bmap_spmd, fix_bmap_epmd; 1034 1035 #ifdef CONFIG_RANDOMIZE_BASE 1036 if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) { 1037 u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa); 1038 u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start); 1039 u32 nr_pos; 1040 1041 if (kaslr_seed == 0) 1042 kaslr_seed = __pi_get_kaslr_seed(dtb_pa); 1043 /* 1044 * Compute the number of positions available: we are limited 1045 * by the early page table that only has one PUD and we must 1046 * be aligned on PMD_SIZE. 1047 */ 1048 nr_pos = (PUD_SIZE - kernel_size) / PMD_SIZE; 1049 1050 kernel_map.virt_offset = (kaslr_seed % nr_pos) * PMD_SIZE; 1051 } 1052 #endif 1053 1054 kernel_map.virt_addr = KERNEL_LINK_ADDR + kernel_map.virt_offset; 1055 1056 kernel_map.phys_addr = (uintptr_t)(&_start); 1057 kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr; 1058 kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr; 1059 1060 #if defined(CONFIG_64BIT) 1061 set_satp_mode(dtb_pa); 1062 set_mmap_rnd_bits_max(); 1063 #endif 1064 1065 /* 1066 * In 64-bit, we defer the setup of va_pa_offset to setup_bootmem, 1067 * where we have the system memory layout: this allows us to align 1068 * the physical and virtual mappings and then make use of PUD/P4D/PGD 1069 * for the linear mapping. This is only possible because the kernel 1070 * mapping lies outside the linear mapping. 1071 * In 32-bit however, as the kernel resides in the linear mapping, 1072 * setup_vm_final can not change the mapping established here, 1073 * otherwise the same kernel addresses would get mapped to different 1074 * physical addresses (if the start of dram is different from the 1075 * kernel physical address start). 1076 */ 1077 kernel_map.va_pa_offset = IS_ENABLED(CONFIG_64BIT) ? 1078 0UL : PAGE_OFFSET - kernel_map.phys_addr; 1079 1080 memory_limit = KERN_VIRT_SIZE; 1081 1082 /* Sanity check alignment and size */ 1083 BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); 1084 BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0); 1085 1086 #ifdef CONFIG_64BIT 1087 /* 1088 * The last 4K bytes of the addressable memory can not be mapped because 1089 * of IS_ERR_VALUE macro. 1090 */ 1091 BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); 1092 #endif 1093 1094 #ifdef CONFIG_RELOCATABLE 1095 /* 1096 * Early page table uses only one PUD, which makes it possible 1097 * to map PUD_SIZE aligned on PUD_SIZE: if the relocation offset 1098 * makes the kernel cross over a PUD_SIZE boundary, raise a bug 1099 * since a part of the kernel would not get mapped. 1100 */ 1101 if (IS_ENABLED(CONFIG_64BIT)) 1102 BUG_ON(PUD_SIZE - (kernel_map.virt_addr & (PUD_SIZE - 1)) < kernel_map.size); 1103 relocate_kernel(); 1104 #endif 1105 1106 apply_early_boot_alternatives(); 1107 pt_ops_set_early(); 1108 1109 /* Setup early PGD for fixmap */ 1110 create_pgd_mapping(early_pg_dir, FIXADDR_START, 1111 fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE); 1112 1113 #ifndef __PAGETABLE_PMD_FOLDED 1114 /* Setup fixmap P4D and PUD */ 1115 if (pgtable_l5_enabled) 1116 create_p4d_mapping(fixmap_p4d, FIXADDR_START, 1117 (uintptr_t)fixmap_pud, P4D_SIZE, PAGE_TABLE); 1118 /* Setup fixmap PUD and PMD */ 1119 if (pgtable_l4_enabled) 1120 create_pud_mapping(fixmap_pud, FIXADDR_START, 1121 (uintptr_t)fixmap_pmd, PUD_SIZE, PAGE_TABLE); 1122 create_pmd_mapping(fixmap_pmd, FIXADDR_START, 1123 (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE); 1124 /* Setup trampoline PGD and PMD */ 1125 create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr, 1126 trampoline_pgd_next, PGDIR_SIZE, PAGE_TABLE); 1127 if (pgtable_l5_enabled) 1128 create_p4d_mapping(trampoline_p4d, kernel_map.virt_addr, 1129 (uintptr_t)trampoline_pud, P4D_SIZE, PAGE_TABLE); 1130 if (pgtable_l4_enabled) 1131 create_pud_mapping(trampoline_pud, kernel_map.virt_addr, 1132 (uintptr_t)trampoline_pmd, PUD_SIZE, PAGE_TABLE); 1133 create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr, 1134 kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC); 1135 #else 1136 /* Setup trampoline PGD */ 1137 create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr, 1138 kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC); 1139 #endif 1140 1141 /* 1142 * Setup early PGD covering entire kernel which will allow 1143 * us to reach paging_init(). We map all memory banks later 1144 * in setup_vm_final() below. 1145 */ 1146 create_kernel_page_table(early_pg_dir, true); 1147 1148 /* Setup early mapping for FDT early scan */ 1149 create_fdt_early_page_table(__fix_to_virt(FIX_FDT), dtb_pa); 1150 1151 /* 1152 * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap 1153 * range can not span multiple pmds. 1154 */ 1155 BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT) 1156 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT)); 1157 1158 #ifndef __PAGETABLE_PMD_FOLDED 1159 /* 1160 * Early ioremap fixmap is already created as it lies within first 2MB 1161 * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END 1162 * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn 1163 * the user if not. 1164 */ 1165 fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))]; 1166 fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))]; 1167 if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) { 1168 WARN_ON(1); 1169 pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n", 1170 pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd)); 1171 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n", 1172 fix_to_virt(FIX_BTMAP_BEGIN)); 1173 pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n", 1174 fix_to_virt(FIX_BTMAP_END)); 1175 1176 pr_warn("FIX_BTMAP_END: %d\n", FIX_BTMAP_END); 1177 pr_warn("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN); 1178 } 1179 #endif 1180 1181 pt_ops_set_fixmap(); 1182 } 1183 1184 static void __meminit create_linear_mapping_range(phys_addr_t start, phys_addr_t end, 1185 uintptr_t fixed_map_size, const pgprot_t *pgprot) 1186 { 1187 phys_addr_t pa; 1188 uintptr_t va, map_size; 1189 1190 for (pa = start; pa < end; pa += map_size) { 1191 va = (uintptr_t)__va(pa); 1192 map_size = fixed_map_size ? fixed_map_size : 1193 best_map_size(pa, va, end - pa); 1194 1195 create_pgd_mapping(swapper_pg_dir, va, pa, map_size, 1196 pgprot ? *pgprot : pgprot_from_va(va)); 1197 } 1198 } 1199 1200 static void __init create_linear_mapping_page_table(void) 1201 { 1202 phys_addr_t start, end; 1203 phys_addr_t kfence_pool __maybe_unused; 1204 u64 i; 1205 1206 #ifdef CONFIG_STRICT_KERNEL_RWX 1207 phys_addr_t ktext_start = __pa_symbol(_start); 1208 phys_addr_t ktext_size = __init_data_begin - _start; 1209 phys_addr_t krodata_start = __pa_symbol(__start_rodata); 1210 phys_addr_t krodata_size = _data - __start_rodata; 1211 1212 /* Isolate kernel text and rodata so they don't get mapped with a PUD */ 1213 memblock_mark_nomap(ktext_start, ktext_size); 1214 memblock_mark_nomap(krodata_start, krodata_size); 1215 #endif 1216 1217 #ifdef CONFIG_KFENCE 1218 /* 1219 * kfence pool must be backed by PAGE_SIZE mappings, so allocate it 1220 * before we setup the linear mapping so that we avoid using hugepages 1221 * for this region. 1222 */ 1223 kfence_pool = memblock_phys_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); 1224 BUG_ON(!kfence_pool); 1225 1226 memblock_mark_nomap(kfence_pool, KFENCE_POOL_SIZE); 1227 __kfence_pool = __va(kfence_pool); 1228 #endif 1229 1230 /* Map all memory banks in the linear mapping */ 1231 for_each_mem_range(i, &start, &end) { 1232 if (start >= end) 1233 break; 1234 if (start <= __pa(PAGE_OFFSET) && 1235 __pa(PAGE_OFFSET) < end) 1236 start = __pa(PAGE_OFFSET); 1237 1238 create_linear_mapping_range(start, end, 0, NULL); 1239 } 1240 1241 #ifdef CONFIG_STRICT_KERNEL_RWX 1242 create_linear_mapping_range(ktext_start, ktext_start + ktext_size, 0, NULL); 1243 create_linear_mapping_range(krodata_start, krodata_start + krodata_size, 0, NULL); 1244 1245 memblock_clear_nomap(ktext_start, ktext_size); 1246 memblock_clear_nomap(krodata_start, krodata_size); 1247 #endif 1248 1249 #ifdef CONFIG_KFENCE 1250 create_linear_mapping_range(kfence_pool, kfence_pool + KFENCE_POOL_SIZE, PAGE_SIZE, NULL); 1251 1252 memblock_clear_nomap(kfence_pool, KFENCE_POOL_SIZE); 1253 #endif 1254 } 1255 1256 static void __init setup_vm_final(void) 1257 { 1258 /* Setup swapper PGD for fixmap */ 1259 #if !defined(CONFIG_64BIT) 1260 /* 1261 * In 32-bit, the device tree lies in a pgd entry, so it must be copied 1262 * directly in swapper_pg_dir in addition to the pgd entry that points 1263 * to fixmap_pte. 1264 */ 1265 unsigned long idx = pgd_index(__fix_to_virt(FIX_FDT)); 1266 1267 set_pgd(&swapper_pg_dir[idx], early_pg_dir[idx]); 1268 #endif 1269 create_pgd_mapping(swapper_pg_dir, FIXADDR_START, 1270 __pa_symbol(fixmap_pgd_next), 1271 PGDIR_SIZE, PAGE_TABLE); 1272 1273 /* Map the linear mapping */ 1274 create_linear_mapping_page_table(); 1275 1276 /* Map the kernel */ 1277 if (IS_ENABLED(CONFIG_64BIT)) 1278 create_kernel_page_table(swapper_pg_dir, false); 1279 1280 #ifdef CONFIG_KASAN 1281 kasan_swapper_init(); 1282 #endif 1283 1284 /* Clear fixmap PTE and PMD mappings */ 1285 clear_fixmap(FIX_PTE); 1286 clear_fixmap(FIX_PMD); 1287 clear_fixmap(FIX_PUD); 1288 clear_fixmap(FIX_P4D); 1289 1290 /* Move to swapper page table */ 1291 csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | satp_mode); 1292 local_flush_tlb_all(); 1293 1294 pt_ops_set_late(); 1295 } 1296 #else 1297 asmlinkage void __init setup_vm(uintptr_t dtb_pa) 1298 { 1299 dtb_early_va = (void *)dtb_pa; 1300 dtb_early_pa = dtb_pa; 1301 1302 #ifdef CONFIG_RELOCATABLE 1303 kernel_map.virt_addr = (uintptr_t)_start; 1304 kernel_map.phys_addr = (uintptr_t)_start; 1305 relocate_kernel(); 1306 #endif 1307 } 1308 1309 static inline void setup_vm_final(void) 1310 { 1311 } 1312 #endif /* CONFIG_MMU */ 1313 1314 /* 1315 * reserve_crashkernel() - reserves memory for crash kernel 1316 * 1317 * This function reserves memory area given in "crashkernel=" kernel command 1318 * line parameter. The memory reserved is used by dump capture kernel when 1319 * primary kernel is crashing. 1320 */ 1321 static void __init arch_reserve_crashkernel(void) 1322 { 1323 unsigned long long low_size = 0; 1324 unsigned long long crash_base, crash_size; 1325 bool high = false; 1326 int ret; 1327 1328 if (!IS_ENABLED(CONFIG_CRASH_RESERVE)) 1329 return; 1330 1331 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 1332 &crash_size, &crash_base, 1333 &low_size, NULL, &high); 1334 if (ret) 1335 return; 1336 1337 reserve_crashkernel_generic(crash_size, crash_base, low_size, high); 1338 } 1339 1340 void __init paging_init(void) 1341 { 1342 setup_bootmem(); 1343 setup_vm_final(); 1344 1345 /* Depend on that Linear Mapping is ready */ 1346 memblock_allow_resize(); 1347 } 1348 1349 void __init misc_mem_init(void) 1350 { 1351 early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); 1352 arch_numa_init(); 1353 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1354 /* The entire VMEMMAP region has been populated. Flush TLB for this region */ 1355 local_flush_tlb_kernel_range(VMEMMAP_START, VMEMMAP_END); 1356 #endif 1357 arch_reserve_crashkernel(); 1358 memblock_dump_all(); 1359 } 1360 1361 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1362 void __meminit vmemmap_set_pmd(pmd_t *pmd, void *p, int node, 1363 unsigned long addr, unsigned long next) 1364 { 1365 pmd_set_huge(pmd, virt_to_phys(p), PAGE_KERNEL); 1366 } 1367 1368 int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node, 1369 unsigned long addr, unsigned long next) 1370 { 1371 vmemmap_verify((pte_t *)pmdp, node, addr, next); 1372 return 1; 1373 } 1374 1375 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 1376 struct vmem_altmap *altmap) 1377 { 1378 WARN_ON((start < VMEMMAP_START) || (end > VMEMMAP_END)); 1379 1380 /* 1381 * Note that SPARSEMEM_VMEMMAP is only selected for rv64 and that we 1382 * can't use hugepage mappings for 2-level page table because in case of 1383 * memory hotplug, we are not able to update all the page tables with 1384 * the new PMDs. 1385 */ 1386 return vmemmap_populate_hugepages(start, end, node, altmap); 1387 } 1388 #endif 1389 1390 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT) 1391 /* 1392 * Pre-allocates page-table pages for a specific area in the kernel 1393 * page-table. Only the level which needs to be synchronized between 1394 * all page-tables is allocated because the synchronization can be 1395 * expensive. 1396 */ 1397 static void __init preallocate_pgd_pages_range(unsigned long start, unsigned long end, 1398 const char *area) 1399 { 1400 unsigned long addr; 1401 const char *lvl; 1402 1403 for (addr = start; addr < end && addr >= start; addr = ALIGN(addr + 1, PGDIR_SIZE)) { 1404 pgd_t *pgd = pgd_offset_k(addr); 1405 p4d_t *p4d; 1406 pud_t *pud; 1407 pmd_t *pmd; 1408 1409 lvl = "p4d"; 1410 p4d = p4d_alloc(&init_mm, pgd, addr); 1411 if (!p4d) 1412 goto failed; 1413 1414 if (pgtable_l5_enabled) 1415 continue; 1416 1417 lvl = "pud"; 1418 pud = pud_alloc(&init_mm, p4d, addr); 1419 if (!pud) 1420 goto failed; 1421 1422 if (pgtable_l4_enabled) 1423 continue; 1424 1425 lvl = "pmd"; 1426 pmd = pmd_alloc(&init_mm, pud, addr); 1427 if (!pmd) 1428 goto failed; 1429 } 1430 return; 1431 1432 failed: 1433 /* 1434 * The pages have to be there now or they will be missing in 1435 * process page-tables later. 1436 */ 1437 panic("Failed to pre-allocate %s pages for %s area\n", lvl, area); 1438 } 1439 1440 #define PAGE_END KASAN_SHADOW_START 1441 1442 void __init pgtable_cache_init(void) 1443 { 1444 preallocate_pgd_pages_range(VMALLOC_START, VMALLOC_END, "vmalloc"); 1445 if (IS_ENABLED(CONFIG_MODULES)) 1446 preallocate_pgd_pages_range(MODULES_VADDR, MODULES_END, "bpf/modules"); 1447 if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG)) { 1448 preallocate_pgd_pages_range(VMEMMAP_START, VMEMMAP_END, "vmemmap"); 1449 preallocate_pgd_pages_range(PAGE_OFFSET, PAGE_END, "direct map"); 1450 if (IS_ENABLED(CONFIG_KASAN)) 1451 preallocate_pgd_pages_range(KASAN_SHADOW_START, KASAN_SHADOW_END, "kasan"); 1452 } 1453 } 1454 #endif 1455 1456 #ifdef CONFIG_EXECMEM 1457 #ifdef CONFIG_MMU 1458 static struct execmem_info execmem_info __ro_after_init; 1459 1460 struct execmem_info __init *execmem_arch_setup(void) 1461 { 1462 execmem_info = (struct execmem_info){ 1463 .ranges = { 1464 [EXECMEM_DEFAULT] = { 1465 .start = MODULES_VADDR, 1466 .end = MODULES_END, 1467 .pgprot = PAGE_KERNEL, 1468 .alignment = 1, 1469 }, 1470 [EXECMEM_KPROBES] = { 1471 .start = VMALLOC_START, 1472 .end = VMALLOC_END, 1473 .pgprot = PAGE_KERNEL_READ_EXEC, 1474 .alignment = 1, 1475 }, 1476 [EXECMEM_BPF] = { 1477 .start = BPF_JIT_REGION_START, 1478 .end = BPF_JIT_REGION_END, 1479 .pgprot = PAGE_KERNEL, 1480 .alignment = PAGE_SIZE, 1481 }, 1482 }, 1483 }; 1484 1485 return &execmem_info; 1486 } 1487 #endif /* CONFIG_MMU */ 1488 #endif /* CONFIG_EXECMEM */ 1489 1490 #ifdef CONFIG_MEMORY_HOTPLUG 1491 static void __meminit free_pte_table(pte_t *pte_start, pmd_t *pmd) 1492 { 1493 struct page *page = pmd_page(*pmd); 1494 struct ptdesc *ptdesc = page_ptdesc(page); 1495 pte_t *pte; 1496 int i; 1497 1498 for (i = 0; i < PTRS_PER_PTE; i++) { 1499 pte = pte_start + i; 1500 if (!pte_none(*pte)) 1501 return; 1502 } 1503 1504 pagetable_dtor(ptdesc); 1505 if (PageReserved(page)) 1506 free_reserved_page(page); 1507 else 1508 pagetable_free(ptdesc); 1509 pmd_clear(pmd); 1510 } 1511 1512 static void __meminit free_pmd_table(pmd_t *pmd_start, pud_t *pud, bool is_vmemmap) 1513 { 1514 struct page *page = pud_page(*pud); 1515 struct ptdesc *ptdesc = page_ptdesc(page); 1516 pmd_t *pmd; 1517 int i; 1518 1519 for (i = 0; i < PTRS_PER_PMD; i++) { 1520 pmd = pmd_start + i; 1521 if (!pmd_none(*pmd)) 1522 return; 1523 } 1524 1525 if (!is_vmemmap) 1526 pagetable_dtor(ptdesc); 1527 if (PageReserved(page)) 1528 free_reserved_page(page); 1529 else 1530 pagetable_free(ptdesc); 1531 pud_clear(pud); 1532 } 1533 1534 static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d) 1535 { 1536 struct page *page = p4d_page(*p4d); 1537 pud_t *pud; 1538 int i; 1539 1540 for (i = 0; i < PTRS_PER_PUD; i++) { 1541 pud = pud_start + i; 1542 if (!pud_none(*pud)) 1543 return; 1544 } 1545 1546 if (PageReserved(page)) 1547 free_reserved_page(page); 1548 else 1549 __free_pages(page, 0); 1550 p4d_clear(p4d); 1551 } 1552 1553 static void __meminit free_vmemmap_storage(struct page *page, size_t size, 1554 struct vmem_altmap *altmap) 1555 { 1556 int order = get_order(size); 1557 1558 if (altmap) { 1559 vmem_altmap_free(altmap, size >> PAGE_SHIFT); 1560 return; 1561 } 1562 1563 if (PageReserved(page)) { 1564 unsigned int nr_pages = 1 << order; 1565 1566 while (nr_pages--) 1567 free_reserved_page(page++); 1568 return; 1569 } 1570 1571 __free_pages(page, order); 1572 } 1573 1574 static void __meminit remove_pte_mapping(pte_t *pte_base, unsigned long addr, unsigned long end, 1575 bool is_vmemmap, struct vmem_altmap *altmap) 1576 { 1577 unsigned long next; 1578 pte_t *ptep, pte; 1579 1580 for (; addr < end; addr = next) { 1581 next = (addr + PAGE_SIZE) & PAGE_MASK; 1582 if (next > end) 1583 next = end; 1584 1585 ptep = pte_base + pte_index(addr); 1586 pte = ptep_get(ptep); 1587 if (!pte_present(*ptep)) 1588 continue; 1589 1590 pte_clear(&init_mm, addr, ptep); 1591 if (is_vmemmap) 1592 free_vmemmap_storage(pte_page(pte), PAGE_SIZE, altmap); 1593 } 1594 } 1595 1596 static void __meminit remove_pmd_mapping(pmd_t *pmd_base, unsigned long addr, unsigned long end, 1597 bool is_vmemmap, struct vmem_altmap *altmap) 1598 { 1599 unsigned long next; 1600 pte_t *pte_base; 1601 pmd_t *pmdp, pmd; 1602 1603 for (; addr < end; addr = next) { 1604 next = pmd_addr_end(addr, end); 1605 pmdp = pmd_base + pmd_index(addr); 1606 pmd = pmdp_get(pmdp); 1607 if (!pmd_present(pmd)) 1608 continue; 1609 1610 if (pmd_leaf(pmd)) { 1611 pmd_clear(pmdp); 1612 if (is_vmemmap) 1613 free_vmemmap_storage(pmd_page(pmd), PMD_SIZE, altmap); 1614 continue; 1615 } 1616 1617 pte_base = (pte_t *)pmd_page_vaddr(*pmdp); 1618 remove_pte_mapping(pte_base, addr, next, is_vmemmap, altmap); 1619 free_pte_table(pte_base, pmdp); 1620 } 1621 } 1622 1623 static void __meminit remove_pud_mapping(pud_t *pud_base, unsigned long addr, unsigned long end, 1624 bool is_vmemmap, struct vmem_altmap *altmap) 1625 { 1626 unsigned long next; 1627 pud_t *pudp, pud; 1628 pmd_t *pmd_base; 1629 1630 for (; addr < end; addr = next) { 1631 next = pud_addr_end(addr, end); 1632 pudp = pud_base + pud_index(addr); 1633 pud = pudp_get(pudp); 1634 if (!pud_present(pud)) 1635 continue; 1636 1637 if (pud_leaf(pud)) { 1638 if (pgtable_l4_enabled) { 1639 pud_clear(pudp); 1640 if (is_vmemmap) 1641 free_vmemmap_storage(pud_page(pud), PUD_SIZE, altmap); 1642 } 1643 continue; 1644 } 1645 1646 pmd_base = pmd_offset(pudp, 0); 1647 remove_pmd_mapping(pmd_base, addr, next, is_vmemmap, altmap); 1648 1649 if (pgtable_l4_enabled) 1650 free_pmd_table(pmd_base, pudp, is_vmemmap); 1651 } 1652 } 1653 1654 static void __meminit remove_p4d_mapping(p4d_t *p4d_base, unsigned long addr, unsigned long end, 1655 bool is_vmemmap, struct vmem_altmap *altmap) 1656 { 1657 unsigned long next; 1658 p4d_t *p4dp, p4d; 1659 pud_t *pud_base; 1660 1661 for (; addr < end; addr = next) { 1662 next = p4d_addr_end(addr, end); 1663 p4dp = p4d_base + p4d_index(addr); 1664 p4d = p4dp_get(p4dp); 1665 if (!p4d_present(p4d)) 1666 continue; 1667 1668 if (p4d_leaf(p4d)) { 1669 if (pgtable_l5_enabled) { 1670 p4d_clear(p4dp); 1671 if (is_vmemmap) 1672 free_vmemmap_storage(p4d_page(p4d), P4D_SIZE, altmap); 1673 } 1674 continue; 1675 } 1676 1677 pud_base = pud_offset(p4dp, 0); 1678 remove_pud_mapping(pud_base, addr, next, is_vmemmap, altmap); 1679 1680 if (pgtable_l5_enabled) 1681 free_pud_table(pud_base, p4dp); 1682 } 1683 } 1684 1685 static void __meminit remove_pgd_mapping(unsigned long va, unsigned long end, bool is_vmemmap, 1686 struct vmem_altmap *altmap) 1687 { 1688 unsigned long addr, next; 1689 p4d_t *p4d_base; 1690 pgd_t *pgd; 1691 1692 for (addr = va; addr < end; addr = next) { 1693 next = pgd_addr_end(addr, end); 1694 pgd = pgd_offset_k(addr); 1695 1696 if (!pgd_present(*pgd)) 1697 continue; 1698 1699 if (pgd_leaf(*pgd)) 1700 continue; 1701 1702 p4d_base = p4d_offset(pgd, 0); 1703 remove_p4d_mapping(p4d_base, addr, next, is_vmemmap, altmap); 1704 } 1705 1706 flush_tlb_all(); 1707 } 1708 1709 static void __meminit remove_linear_mapping(phys_addr_t start, u64 size) 1710 { 1711 unsigned long va = (unsigned long)__va(start); 1712 unsigned long end = (unsigned long)__va(start + size); 1713 1714 remove_pgd_mapping(va, end, false, NULL); 1715 } 1716 1717 struct range arch_get_mappable_range(void) 1718 { 1719 struct range mhp_range; 1720 1721 mhp_range.start = __pa(PAGE_OFFSET); 1722 mhp_range.end = __pa(PAGE_END - 1); 1723 return mhp_range; 1724 } 1725 1726 int __ref arch_add_memory(int nid, u64 start, u64 size, struct mhp_params *params) 1727 { 1728 int ret = 0; 1729 1730 create_linear_mapping_range(start, start + size, 0, ¶ms->pgprot); 1731 ret = __add_pages(nid, start >> PAGE_SHIFT, size >> PAGE_SHIFT, params); 1732 if (ret) { 1733 remove_linear_mapping(start, size); 1734 goto out; 1735 } 1736 1737 max_pfn = PFN_UP(start + size); 1738 max_low_pfn = max_pfn; 1739 1740 out: 1741 flush_tlb_all(); 1742 return ret; 1743 } 1744 1745 void __ref arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) 1746 { 1747 __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT, altmap); 1748 remove_linear_mapping(start, size); 1749 flush_tlb_all(); 1750 } 1751 1752 void __ref vmemmap_free(unsigned long start, unsigned long end, struct vmem_altmap *altmap) 1753 { 1754 remove_pgd_mapping(start, end, true, altmap); 1755 } 1756 #endif /* CONFIG_MEMORY_HOTPLUG */ 1757