1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Based on arch/arm/mm/init.c 4 * 5 * Copyright (C) 1995-2005 Russell King 6 * Copyright (C) 2012 ARM Ltd. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/export.h> 11 #include <linux/errno.h> 12 #include <linux/swap.h> 13 #include <linux/init.h> 14 #include <linux/cache.h> 15 #include <linux/mman.h> 16 #include <linux/nodemask.h> 17 #include <linux/initrd.h> 18 #include <linux/gfp.h> 19 #include <linux/memblock.h> 20 #include <linux/sort.h> 21 #include <linux/of.h> 22 #include <linux/of_fdt.h> 23 #include <linux/dma-direct.h> 24 #include <linux/dma-mapping.h> 25 #include <linux/dma-contiguous.h> 26 #include <linux/efi.h> 27 #include <linux/swiotlb.h> 28 #include <linux/vmalloc.h> 29 #include <linux/mm.h> 30 #include <linux/kexec.h> 31 #include <linux/crash_dump.h> 32 33 #include <asm/boot.h> 34 #include <asm/fixmap.h> 35 #include <asm/kasan.h> 36 #include <asm/kernel-pgtable.h> 37 #include <asm/memory.h> 38 #include <asm/numa.h> 39 #include <asm/sections.h> 40 #include <asm/setup.h> 41 #include <linux/sizes.h> 42 #include <asm/tlb.h> 43 #include <asm/alternative.h> 44 45 #define ARM64_ZONE_DMA_BITS 30 46 47 /* 48 * We need to be able to catch inadvertent references to memstart_addr 49 * that occur (potentially in generic code) before arm64_memblock_init() 50 * executes, which assigns it its actual value. So use a default value 51 * that cannot be mistaken for a real physical address. 52 */ 53 s64 memstart_addr __ro_after_init = -1; 54 EXPORT_SYMBOL(memstart_addr); 55 56 s64 physvirt_offset __ro_after_init; 57 EXPORT_SYMBOL(physvirt_offset); 58 59 struct page *vmemmap __ro_after_init; 60 EXPORT_SYMBOL(vmemmap); 61 62 /* 63 * We create both ZONE_DMA and ZONE_DMA32. ZONE_DMA covers the first 1G of 64 * memory as some devices, namely the Raspberry Pi 4, have peripherals with 65 * this limited view of the memory. ZONE_DMA32 will cover the rest of the 32 66 * bit addressable memory area. 67 */ 68 phys_addr_t arm64_dma_phys_limit __ro_after_init; 69 static phys_addr_t arm64_dma32_phys_limit __ro_after_init; 70 71 #ifdef CONFIG_KEXEC_CORE 72 /* 73 * reserve_crashkernel() - reserves memory for crash kernel 74 * 75 * This function reserves memory area given in "crashkernel=" kernel command 76 * line parameter. The memory reserved is used by dump capture kernel when 77 * primary kernel is crashing. 78 */ 79 static void __init reserve_crashkernel(void) 80 { 81 unsigned long long crash_base, crash_size; 82 int ret; 83 84 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 85 &crash_size, &crash_base); 86 /* no crashkernel= or invalid value specified */ 87 if (ret || !crash_size) 88 return; 89 90 crash_size = PAGE_ALIGN(crash_size); 91 92 if (crash_base == 0) { 93 /* Current arm64 boot protocol requires 2MB alignment */ 94 crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit, 95 crash_size, SZ_2M); 96 if (crash_base == 0) { 97 pr_warn("cannot allocate crashkernel (size:0x%llx)\n", 98 crash_size); 99 return; 100 } 101 } else { 102 /* User specifies base address explicitly. */ 103 if (!memblock_is_region_memory(crash_base, crash_size)) { 104 pr_warn("cannot reserve crashkernel: region is not memory\n"); 105 return; 106 } 107 108 if (memblock_is_region_reserved(crash_base, crash_size)) { 109 pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n"); 110 return; 111 } 112 113 if (!IS_ALIGNED(crash_base, SZ_2M)) { 114 pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n"); 115 return; 116 } 117 } 118 memblock_reserve(crash_base, crash_size); 119 120 pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", 121 crash_base, crash_base + crash_size, crash_size >> 20); 122 123 crashk_res.start = crash_base; 124 crashk_res.end = crash_base + crash_size - 1; 125 } 126 #else 127 static void __init reserve_crashkernel(void) 128 { 129 } 130 #endif /* CONFIG_KEXEC_CORE */ 131 132 #ifdef CONFIG_CRASH_DUMP 133 static int __init early_init_dt_scan_elfcorehdr(unsigned long node, 134 const char *uname, int depth, void *data) 135 { 136 const __be32 *reg; 137 int len; 138 139 if (depth != 1 || strcmp(uname, "chosen") != 0) 140 return 0; 141 142 reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 143 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) 144 return 1; 145 146 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, ®); 147 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, ®); 148 149 return 1; 150 } 151 152 /* 153 * reserve_elfcorehdr() - reserves memory for elf core header 154 * 155 * This function reserves the memory occupied by an elf core header 156 * described in the device tree. This region contains all the 157 * information about primary kernel's core image and is used by a dump 158 * capture kernel to access the system memory on primary kernel. 159 */ 160 static void __init reserve_elfcorehdr(void) 161 { 162 of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL); 163 164 if (!elfcorehdr_size) 165 return; 166 167 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 168 pr_warn("elfcorehdr is overlapped\n"); 169 return; 170 } 171 172 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 173 174 pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n", 175 elfcorehdr_size >> 10, elfcorehdr_addr); 176 } 177 #else 178 static void __init reserve_elfcorehdr(void) 179 { 180 } 181 #endif /* CONFIG_CRASH_DUMP */ 182 183 /* 184 * Return the maximum physical address for a zone with a given address size 185 * limit. It currently assumes that for memory starting above 4G, 32-bit 186 * devices will use a DMA offset. 187 */ 188 static phys_addr_t __init max_zone_phys(unsigned int zone_bits) 189 { 190 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, zone_bits); 191 return min(offset + (1ULL << zone_bits), memblock_end_of_DRAM()); 192 } 193 194 #ifdef CONFIG_NUMA 195 196 static void __init zone_sizes_init(unsigned long min, unsigned long max) 197 { 198 unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; 199 200 #ifdef CONFIG_ZONE_DMA 201 max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); 202 #endif 203 #ifdef CONFIG_ZONE_DMA32 204 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(arm64_dma32_phys_limit); 205 #endif 206 max_zone_pfns[ZONE_NORMAL] = max; 207 208 free_area_init_nodes(max_zone_pfns); 209 } 210 211 #else 212 213 static void __init zone_sizes_init(unsigned long min, unsigned long max) 214 { 215 struct memblock_region *reg; 216 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; 217 unsigned long max_dma32 = min; 218 unsigned long __maybe_unused max_dma = min; 219 220 memset(zone_size, 0, sizeof(zone_size)); 221 222 #ifdef CONFIG_ZONE_DMA 223 max_dma = PFN_DOWN(arm64_dma_phys_limit); 224 zone_size[ZONE_DMA] = max_dma - min; 225 max_dma32 = max_dma; 226 #endif 227 #ifdef CONFIG_ZONE_DMA32 228 max_dma32 = PFN_DOWN(arm64_dma32_phys_limit); 229 zone_size[ZONE_DMA32] = max_dma32 - max_dma; 230 #endif 231 zone_size[ZONE_NORMAL] = max - max_dma32; 232 233 memcpy(zhole_size, zone_size, sizeof(zhole_size)); 234 235 for_each_memblock(memory, reg) { 236 unsigned long start = memblock_region_memory_base_pfn(reg); 237 unsigned long end = memblock_region_memory_end_pfn(reg); 238 239 if (start >= max) 240 continue; 241 #ifdef CONFIG_ZONE_DMA 242 if (start < max_dma) { 243 unsigned long dma_end = min_not_zero(end, max_dma); 244 zhole_size[ZONE_DMA] -= dma_end - start; 245 } 246 #endif 247 #ifdef CONFIG_ZONE_DMA32 248 if (start < max_dma32) { 249 unsigned long dma32_end = min(end, max_dma32); 250 unsigned long dma32_start = max(start, max_dma); 251 zhole_size[ZONE_DMA32] -= dma32_end - dma32_start; 252 } 253 #endif 254 if (end > max_dma32) { 255 unsigned long normal_end = min(end, max); 256 unsigned long normal_start = max(start, max_dma32); 257 zhole_size[ZONE_NORMAL] -= normal_end - normal_start; 258 } 259 } 260 261 free_area_init_node(0, zone_size, min, zhole_size); 262 } 263 264 #endif /* CONFIG_NUMA */ 265 266 int pfn_valid(unsigned long pfn) 267 { 268 phys_addr_t addr = pfn << PAGE_SHIFT; 269 270 if ((addr >> PAGE_SHIFT) != pfn) 271 return 0; 272 273 #ifdef CONFIG_SPARSEMEM 274 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 275 return 0; 276 277 if (!valid_section(__nr_to_section(pfn_to_section_nr(pfn)))) 278 return 0; 279 #endif 280 return memblock_is_map_memory(addr); 281 } 282 EXPORT_SYMBOL(pfn_valid); 283 284 static phys_addr_t memory_limit = PHYS_ADDR_MAX; 285 286 /* 287 * Limit the memory size that was specified via FDT. 288 */ 289 static int __init early_mem(char *p) 290 { 291 if (!p) 292 return 1; 293 294 memory_limit = memparse(p, &p) & PAGE_MASK; 295 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20); 296 297 return 0; 298 } 299 early_param("mem", early_mem); 300 301 static int __init early_init_dt_scan_usablemem(unsigned long node, 302 const char *uname, int depth, void *data) 303 { 304 struct memblock_region *usablemem = data; 305 const __be32 *reg; 306 int len; 307 308 if (depth != 1 || strcmp(uname, "chosen") != 0) 309 return 0; 310 311 reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 312 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) 313 return 1; 314 315 usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); 316 usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); 317 318 return 1; 319 } 320 321 static void __init fdt_enforce_memory_region(void) 322 { 323 struct memblock_region reg = { 324 .size = 0, 325 }; 326 327 of_scan_flat_dt(early_init_dt_scan_usablemem, ®); 328 329 if (reg.size) 330 memblock_cap_memory_range(reg.base, reg.size); 331 } 332 333 void __init arm64_memblock_init(void) 334 { 335 const s64 linear_region_size = BIT(vabits_actual - 1); 336 337 /* Handle linux,usable-memory-range property */ 338 fdt_enforce_memory_region(); 339 340 /* Remove memory above our supported physical address size */ 341 memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX); 342 343 /* 344 * Select a suitable value for the base of physical memory. 345 */ 346 memstart_addr = round_down(memblock_start_of_DRAM(), 347 ARM64_MEMSTART_ALIGN); 348 349 physvirt_offset = PHYS_OFFSET - PAGE_OFFSET; 350 351 vmemmap = ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)); 352 353 /* 354 * If we are running with a 52-bit kernel VA config on a system that 355 * does not support it, we have to offset our vmemmap and physvirt_offset 356 * s.t. we avoid the 52-bit portion of the direct linear map 357 */ 358 if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) { 359 vmemmap += (_PAGE_OFFSET(48) - _PAGE_OFFSET(52)) >> PAGE_SHIFT; 360 physvirt_offset = PHYS_OFFSET - _PAGE_OFFSET(48); 361 } 362 363 /* 364 * Remove the memory that we will not be able to cover with the 365 * linear mapping. Take care not to clip the kernel which may be 366 * high in memory. 367 */ 368 memblock_remove(max_t(u64, memstart_addr + linear_region_size, 369 __pa_symbol(_end)), ULLONG_MAX); 370 if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) { 371 /* ensure that memstart_addr remains sufficiently aligned */ 372 memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size, 373 ARM64_MEMSTART_ALIGN); 374 memblock_remove(0, memstart_addr); 375 } 376 377 /* 378 * Apply the memory limit if it was set. Since the kernel may be loaded 379 * high up in memory, add back the kernel region that must be accessible 380 * via the linear mapping. 381 */ 382 if (memory_limit != PHYS_ADDR_MAX) { 383 memblock_mem_limit_remove_map(memory_limit); 384 memblock_add(__pa_symbol(_text), (u64)(_end - _text)); 385 } 386 387 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { 388 /* 389 * Add back the memory we just removed if it results in the 390 * initrd to become inaccessible via the linear mapping. 391 * Otherwise, this is a no-op 392 */ 393 u64 base = phys_initrd_start & PAGE_MASK; 394 u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base; 395 396 /* 397 * We can only add back the initrd memory if we don't end up 398 * with more memory than we can address via the linear mapping. 399 * It is up to the bootloader to position the kernel and the 400 * initrd reasonably close to each other (i.e., within 32 GB of 401 * each other) so that all granule/#levels combinations can 402 * always access both. 403 */ 404 if (WARN(base < memblock_start_of_DRAM() || 405 base + size > memblock_start_of_DRAM() + 406 linear_region_size, 407 "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) { 408 phys_initrd_size = 0; 409 } else { 410 memblock_remove(base, size); /* clear MEMBLOCK_ flags */ 411 memblock_add(base, size); 412 memblock_reserve(base, size); 413 } 414 } 415 416 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { 417 extern u16 memstart_offset_seed; 418 u64 range = linear_region_size - 419 (memblock_end_of_DRAM() - memblock_start_of_DRAM()); 420 421 /* 422 * If the size of the linear region exceeds, by a sufficient 423 * margin, the size of the region that the available physical 424 * memory spans, randomize the linear region as well. 425 */ 426 if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { 427 range /= ARM64_MEMSTART_ALIGN; 428 memstart_addr -= ARM64_MEMSTART_ALIGN * 429 ((range * memstart_offset_seed) >> 16); 430 } 431 } 432 433 /* 434 * Register the kernel text, kernel data, initrd, and initial 435 * pagetables with memblock. 436 */ 437 memblock_reserve(__pa_symbol(_text), _end - _text); 438 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { 439 /* the generic initrd code expects virtual addresses */ 440 initrd_start = __phys_to_virt(phys_initrd_start); 441 initrd_end = initrd_start + phys_initrd_size; 442 } 443 444 early_init_fdt_scan_reserved_mem(); 445 446 if (IS_ENABLED(CONFIG_ZONE_DMA)) { 447 zone_dma_bits = ARM64_ZONE_DMA_BITS; 448 arm64_dma_phys_limit = max_zone_phys(ARM64_ZONE_DMA_BITS); 449 } 450 451 if (IS_ENABLED(CONFIG_ZONE_DMA32)) 452 arm64_dma32_phys_limit = max_zone_phys(32); 453 else 454 arm64_dma32_phys_limit = PHYS_MASK + 1; 455 456 reserve_crashkernel(); 457 458 reserve_elfcorehdr(); 459 460 high_memory = __va(memblock_end_of_DRAM() - 1) + 1; 461 462 dma_contiguous_reserve(arm64_dma32_phys_limit); 463 } 464 465 void __init bootmem_init(void) 466 { 467 unsigned long min, max; 468 469 min = PFN_UP(memblock_start_of_DRAM()); 470 max = PFN_DOWN(memblock_end_of_DRAM()); 471 472 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT); 473 474 max_pfn = max_low_pfn = max; 475 min_low_pfn = min; 476 477 arm64_numa_init(); 478 /* 479 * Sparsemem tries to allocate bootmem in memory_present(), so must be 480 * done after the fixed reservations. 481 */ 482 memblocks_present(); 483 484 sparse_init(); 485 zone_sizes_init(min, max); 486 487 memblock_dump_all(); 488 } 489 490 #ifndef CONFIG_SPARSEMEM_VMEMMAP 491 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn) 492 { 493 struct page *start_pg, *end_pg; 494 unsigned long pg, pgend; 495 496 /* 497 * Convert start_pfn/end_pfn to a struct page pointer. 498 */ 499 start_pg = pfn_to_page(start_pfn - 1) + 1; 500 end_pg = pfn_to_page(end_pfn - 1) + 1; 501 502 /* 503 * Convert to physical addresses, and round start upwards and end 504 * downwards. 505 */ 506 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg)); 507 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK; 508 509 /* 510 * If there are free pages between these, free the section of the 511 * memmap array. 512 */ 513 if (pg < pgend) 514 memblock_free(pg, pgend - pg); 515 } 516 517 /* 518 * The mem_map array can get very big. Free the unused area of the memory map. 519 */ 520 static void __init free_unused_memmap(void) 521 { 522 unsigned long start, prev_end = 0; 523 struct memblock_region *reg; 524 525 for_each_memblock(memory, reg) { 526 start = __phys_to_pfn(reg->base); 527 528 #ifdef CONFIG_SPARSEMEM 529 /* 530 * Take care not to free memmap entries that don't exist due 531 * to SPARSEMEM sections which aren't present. 532 */ 533 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION)); 534 #endif 535 /* 536 * If we had a previous bank, and there is a space between the 537 * current bank and the previous, free it. 538 */ 539 if (prev_end && prev_end < start) 540 free_memmap(prev_end, start); 541 542 /* 543 * Align up here since the VM subsystem insists that the 544 * memmap entries are valid from the bank end aligned to 545 * MAX_ORDER_NR_PAGES. 546 */ 547 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size), 548 MAX_ORDER_NR_PAGES); 549 } 550 551 #ifdef CONFIG_SPARSEMEM 552 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) 553 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION)); 554 #endif 555 } 556 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 557 558 /* 559 * mem_init() marks the free areas in the mem_map and tells us how much memory 560 * is free. This is done after various parts of the system have claimed their 561 * memory after the kernel image. 562 */ 563 void __init mem_init(void) 564 { 565 if (swiotlb_force == SWIOTLB_FORCE || 566 max_pfn > PFN_DOWN(arm64_dma_phys_limit ? : arm64_dma32_phys_limit)) 567 swiotlb_init(1); 568 else 569 swiotlb_force = SWIOTLB_NO_FORCE; 570 571 set_max_mapnr(max_pfn - PHYS_PFN_OFFSET); 572 573 #ifndef CONFIG_SPARSEMEM_VMEMMAP 574 free_unused_memmap(); 575 #endif 576 /* this will put all unused low memory onto the freelists */ 577 memblock_free_all(); 578 579 mem_init_print_info(NULL); 580 581 /* 582 * Check boundaries twice: Some fundamental inconsistencies can be 583 * detected at build time already. 584 */ 585 #ifdef CONFIG_COMPAT 586 BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64); 587 #endif 588 589 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { 590 extern int sysctl_overcommit_memory; 591 /* 592 * On a machine this small we won't get anywhere without 593 * overcommit, so turn it on by default. 594 */ 595 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; 596 } 597 } 598 599 void free_initmem(void) 600 { 601 free_reserved_area(lm_alias(__init_begin), 602 lm_alias(__init_end), 603 POISON_FREE_INITMEM, "unused kernel"); 604 /* 605 * Unmap the __init region but leave the VM area in place. This 606 * prevents the region from being reused for kernel modules, which 607 * is not supported by kallsyms. 608 */ 609 unmap_kernel_range((u64)__init_begin, (u64)(__init_end - __init_begin)); 610 } 611 612 /* 613 * Dump out memory limit information on panic. 614 */ 615 static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p) 616 { 617 if (memory_limit != PHYS_ADDR_MAX) { 618 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20); 619 } else { 620 pr_emerg("Memory Limit: none\n"); 621 } 622 return 0; 623 } 624 625 static struct notifier_block mem_limit_notifier = { 626 .notifier_call = dump_mem_limit, 627 }; 628 629 static int __init register_mem_limit_dumper(void) 630 { 631 atomic_notifier_chain_register(&panic_notifier_list, 632 &mem_limit_notifier); 633 return 0; 634 } 635 __initcall(register_mem_limit_dumper); 636