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-map-ops.h> 25 #include <linux/efi.h> 26 #include <linux/swiotlb.h> 27 #include <linux/vmalloc.h> 28 #include <linux/mm.h> 29 #include <linux/kexec.h> 30 #include <linux/crash_dump.h> 31 #include <linux/hugetlb.h> 32 #include <linux/acpi_iort.h> 33 34 #include <asm/boot.h> 35 #include <asm/fixmap.h> 36 #include <asm/kasan.h> 37 #include <asm/kernel-pgtable.h> 38 #include <asm/kvm_host.h> 39 #include <asm/memory.h> 40 #include <asm/numa.h> 41 #include <asm/sections.h> 42 #include <asm/setup.h> 43 #include <linux/sizes.h> 44 #include <asm/tlb.h> 45 #include <asm/alternative.h> 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 /* 57 * If the corresponding config options are enabled, we create both ZONE_DMA 58 * and ZONE_DMA32. By default ZONE_DMA covers the 32-bit addressable memory 59 * unless restricted on specific platforms (e.g. 30-bit on Raspberry Pi 4). 60 * In such case, ZONE_DMA32 covers the rest of the 32-bit addressable memory, 61 * otherwise it is empty. 62 */ 63 phys_addr_t arm64_dma_phys_limit __ro_after_init; 64 65 #ifdef CONFIG_KEXEC_CORE 66 /* 67 * reserve_crashkernel() - reserves memory for crash kernel 68 * 69 * This function reserves memory area given in "crashkernel=" kernel command 70 * line parameter. The memory reserved is used by dump capture kernel when 71 * primary kernel is crashing. 72 */ 73 static void __init reserve_crashkernel(void) 74 { 75 unsigned long long crash_base, crash_size; 76 int ret; 77 78 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 79 &crash_size, &crash_base); 80 /* no crashkernel= or invalid value specified */ 81 if (ret || !crash_size) 82 return; 83 84 crash_size = PAGE_ALIGN(crash_size); 85 86 if (crash_base == 0) { 87 /* Current arm64 boot protocol requires 2MB alignment */ 88 crash_base = memblock_find_in_range(0, arm64_dma_phys_limit, 89 crash_size, SZ_2M); 90 if (crash_base == 0) { 91 pr_warn("cannot allocate crashkernel (size:0x%llx)\n", 92 crash_size); 93 return; 94 } 95 } else { 96 /* User specifies base address explicitly. */ 97 if (!memblock_is_region_memory(crash_base, crash_size)) { 98 pr_warn("cannot reserve crashkernel: region is not memory\n"); 99 return; 100 } 101 102 if (memblock_is_region_reserved(crash_base, crash_size)) { 103 pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n"); 104 return; 105 } 106 107 if (!IS_ALIGNED(crash_base, SZ_2M)) { 108 pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n"); 109 return; 110 } 111 } 112 memblock_reserve(crash_base, crash_size); 113 114 pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", 115 crash_base, crash_base + crash_size, crash_size >> 20); 116 117 crashk_res.start = crash_base; 118 crashk_res.end = crash_base + crash_size - 1; 119 } 120 #else 121 static void __init reserve_crashkernel(void) 122 { 123 } 124 #endif /* CONFIG_KEXEC_CORE */ 125 126 #ifdef CONFIG_CRASH_DUMP 127 static int __init early_init_dt_scan_elfcorehdr(unsigned long node, 128 const char *uname, int depth, void *data) 129 { 130 const __be32 *reg; 131 int len; 132 133 if (depth != 1 || strcmp(uname, "chosen") != 0) 134 return 0; 135 136 reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 137 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) 138 return 1; 139 140 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, ®); 141 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, ®); 142 143 return 1; 144 } 145 146 /* 147 * reserve_elfcorehdr() - reserves memory for elf core header 148 * 149 * This function reserves the memory occupied by an elf core header 150 * described in the device tree. This region contains all the 151 * information about primary kernel's core image and is used by a dump 152 * capture kernel to access the system memory on primary kernel. 153 */ 154 static void __init reserve_elfcorehdr(void) 155 { 156 of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL); 157 158 if (!elfcorehdr_size) 159 return; 160 161 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 162 pr_warn("elfcorehdr is overlapped\n"); 163 return; 164 } 165 166 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 167 168 pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n", 169 elfcorehdr_size >> 10, elfcorehdr_addr); 170 } 171 #else 172 static void __init reserve_elfcorehdr(void) 173 { 174 } 175 #endif /* CONFIG_CRASH_DUMP */ 176 177 /* 178 * Return the maximum physical address for a zone accessible by the given bits 179 * limit. If DRAM starts above 32-bit, expand the zone to the maximum 180 * available memory, otherwise cap it at 32-bit. 181 */ 182 static phys_addr_t __init max_zone_phys(unsigned int zone_bits) 183 { 184 phys_addr_t zone_mask = DMA_BIT_MASK(zone_bits); 185 phys_addr_t phys_start = memblock_start_of_DRAM(); 186 187 if (phys_start > U32_MAX) 188 zone_mask = PHYS_ADDR_MAX; 189 else if (phys_start > zone_mask) 190 zone_mask = U32_MAX; 191 192 return min(zone_mask, memblock_end_of_DRAM() - 1) + 1; 193 } 194 195 static void __init zone_sizes_init(unsigned long min, unsigned long max) 196 { 197 unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; 198 unsigned int __maybe_unused acpi_zone_dma_bits; 199 unsigned int __maybe_unused dt_zone_dma_bits; 200 phys_addr_t __maybe_unused dma32_phys_limit = max_zone_phys(32); 201 202 #ifdef CONFIG_ZONE_DMA 203 acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); 204 dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL)); 205 zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits); 206 arm64_dma_phys_limit = max_zone_phys(zone_dma_bits); 207 max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); 208 #endif 209 #ifdef CONFIG_ZONE_DMA32 210 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit); 211 if (!arm64_dma_phys_limit) 212 arm64_dma_phys_limit = dma32_phys_limit; 213 #endif 214 if (!arm64_dma_phys_limit) 215 arm64_dma_phys_limit = PHYS_MASK + 1; 216 max_zone_pfns[ZONE_NORMAL] = max; 217 218 free_area_init(max_zone_pfns); 219 } 220 221 int pfn_valid(unsigned long pfn) 222 { 223 phys_addr_t addr = PFN_PHYS(pfn); 224 225 /* 226 * Ensure the upper PAGE_SHIFT bits are clear in the 227 * pfn. Else it might lead to false positives when 228 * some of the upper bits are set, but the lower bits 229 * match a valid pfn. 230 */ 231 if (PHYS_PFN(addr) != pfn) 232 return 0; 233 234 #ifdef CONFIG_SPARSEMEM 235 { 236 struct mem_section *ms; 237 238 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 239 return 0; 240 241 ms = __pfn_to_section(pfn); 242 if (!valid_section(ms)) 243 return 0; 244 245 /* 246 * ZONE_DEVICE memory does not have the memblock entries. 247 * memblock_is_map_memory() check for ZONE_DEVICE based 248 * addresses will always fail. Even the normal hotplugged 249 * memory will never have MEMBLOCK_NOMAP flag set in their 250 * memblock entries. Skip memblock search for all non early 251 * memory sections covering all of hotplug memory including 252 * both normal and ZONE_DEVICE based. 253 */ 254 if (!early_section(ms)) 255 return pfn_section_valid(ms, pfn); 256 } 257 #endif 258 return memblock_is_map_memory(addr); 259 } 260 EXPORT_SYMBOL(pfn_valid); 261 262 static phys_addr_t memory_limit = PHYS_ADDR_MAX; 263 264 /* 265 * Limit the memory size that was specified via FDT. 266 */ 267 static int __init early_mem(char *p) 268 { 269 if (!p) 270 return 1; 271 272 memory_limit = memparse(p, &p) & PAGE_MASK; 273 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20); 274 275 return 0; 276 } 277 early_param("mem", early_mem); 278 279 static int __init early_init_dt_scan_usablemem(unsigned long node, 280 const char *uname, int depth, void *data) 281 { 282 struct memblock_region *usablemem = data; 283 const __be32 *reg; 284 int len; 285 286 if (depth != 1 || strcmp(uname, "chosen") != 0) 287 return 0; 288 289 reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 290 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) 291 return 1; 292 293 usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); 294 usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); 295 296 return 1; 297 } 298 299 static void __init fdt_enforce_memory_region(void) 300 { 301 struct memblock_region reg = { 302 .size = 0, 303 }; 304 305 of_scan_flat_dt(early_init_dt_scan_usablemem, ®); 306 307 if (reg.size) 308 memblock_cap_memory_range(reg.base, reg.size); 309 } 310 311 void __init arm64_memblock_init(void) 312 { 313 const s64 linear_region_size = PAGE_END - _PAGE_OFFSET(vabits_actual); 314 315 /* Handle linux,usable-memory-range property */ 316 fdt_enforce_memory_region(); 317 318 /* Remove memory above our supported physical address size */ 319 memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX); 320 321 /* 322 * Select a suitable value for the base of physical memory. 323 */ 324 memstart_addr = round_down(memblock_start_of_DRAM(), 325 ARM64_MEMSTART_ALIGN); 326 327 if ((memblock_end_of_DRAM() - memstart_addr) > linear_region_size) 328 pr_warn("Memory doesn't fit in the linear mapping, VA_BITS too small\n"); 329 330 /* 331 * Remove the memory that we will not be able to cover with the 332 * linear mapping. Take care not to clip the kernel which may be 333 * high in memory. 334 */ 335 memblock_remove(max_t(u64, memstart_addr + linear_region_size, 336 __pa_symbol(_end)), ULLONG_MAX); 337 if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) { 338 /* ensure that memstart_addr remains sufficiently aligned */ 339 memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size, 340 ARM64_MEMSTART_ALIGN); 341 memblock_remove(0, memstart_addr); 342 } 343 344 /* 345 * If we are running with a 52-bit kernel VA config on a system that 346 * does not support it, we have to place the available physical 347 * memory in the 48-bit addressable part of the linear region, i.e., 348 * we have to move it upward. Since memstart_addr represents the 349 * physical address of PAGE_OFFSET, we have to *subtract* from it. 350 */ 351 if (IS_ENABLED(CONFIG_ARM64_VA_BITS_52) && (vabits_actual != 52)) 352 memstart_addr -= _PAGE_OFFSET(48) - _PAGE_OFFSET(52); 353 354 /* 355 * Apply the memory limit if it was set. Since the kernel may be loaded 356 * high up in memory, add back the kernel region that must be accessible 357 * via the linear mapping. 358 */ 359 if (memory_limit != PHYS_ADDR_MAX) { 360 memblock_mem_limit_remove_map(memory_limit); 361 memblock_add(__pa_symbol(_text), (u64)(_end - _text)); 362 } 363 364 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { 365 /* 366 * Add back the memory we just removed if it results in the 367 * initrd to become inaccessible via the linear mapping. 368 * Otherwise, this is a no-op 369 */ 370 u64 base = phys_initrd_start & PAGE_MASK; 371 u64 size = PAGE_ALIGN(phys_initrd_start + phys_initrd_size) - base; 372 373 /* 374 * We can only add back the initrd memory if we don't end up 375 * with more memory than we can address via the linear mapping. 376 * It is up to the bootloader to position the kernel and the 377 * initrd reasonably close to each other (i.e., within 32 GB of 378 * each other) so that all granule/#levels combinations can 379 * always access both. 380 */ 381 if (WARN(base < memblock_start_of_DRAM() || 382 base + size > memblock_start_of_DRAM() + 383 linear_region_size, 384 "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) { 385 phys_initrd_size = 0; 386 } else { 387 memblock_remove(base, size); /* clear MEMBLOCK_ flags */ 388 memblock_add(base, size); 389 memblock_reserve(base, size); 390 } 391 } 392 393 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { 394 extern u16 memstart_offset_seed; 395 u64 mmfr0 = read_cpuid(ID_AA64MMFR0_EL1); 396 int parange = cpuid_feature_extract_unsigned_field( 397 mmfr0, ID_AA64MMFR0_PARANGE_SHIFT); 398 s64 range = linear_region_size - 399 BIT(id_aa64mmfr0_parange_to_phys_shift(parange)); 400 401 /* 402 * If the size of the linear region exceeds, by a sufficient 403 * margin, the size of the region that the physical memory can 404 * span, randomize the linear region as well. 405 */ 406 if (memstart_offset_seed > 0 && range >= (s64)ARM64_MEMSTART_ALIGN) { 407 range /= ARM64_MEMSTART_ALIGN; 408 memstart_addr -= ARM64_MEMSTART_ALIGN * 409 ((range * memstart_offset_seed) >> 16); 410 } 411 } 412 413 /* 414 * Register the kernel text, kernel data, initrd, and initial 415 * pagetables with memblock. 416 */ 417 memblock_reserve(__pa_symbol(_stext), _end - _stext); 418 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && phys_initrd_size) { 419 /* the generic initrd code expects virtual addresses */ 420 initrd_start = __phys_to_virt(phys_initrd_start); 421 initrd_end = initrd_start + phys_initrd_size; 422 } 423 424 early_init_fdt_scan_reserved_mem(); 425 426 reserve_elfcorehdr(); 427 428 high_memory = __va(memblock_end_of_DRAM() - 1) + 1; 429 } 430 431 void __init bootmem_init(void) 432 { 433 unsigned long min, max; 434 435 min = PFN_UP(memblock_start_of_DRAM()); 436 max = PFN_DOWN(memblock_end_of_DRAM()); 437 438 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT); 439 440 max_pfn = max_low_pfn = max; 441 min_low_pfn = min; 442 443 arch_numa_init(); 444 445 /* 446 * must be done after arch_numa_init() which calls numa_init() to 447 * initialize node_online_map that gets used in hugetlb_cma_reserve() 448 * while allocating required CMA size across online nodes. 449 */ 450 #if defined(CONFIG_HUGETLB_PAGE) && defined(CONFIG_CMA) 451 arm64_hugetlb_cma_reserve(); 452 #endif 453 454 dma_pernuma_cma_reserve(); 455 456 kvm_hyp_reserve(); 457 458 /* 459 * sparse_init() tries to allocate memory from memblock, so must be 460 * done after the fixed reservations 461 */ 462 sparse_init(); 463 zone_sizes_init(min, max); 464 465 /* 466 * Reserve the CMA area after arm64_dma_phys_limit was initialised. 467 */ 468 dma_contiguous_reserve(arm64_dma_phys_limit); 469 470 /* 471 * request_standard_resources() depends on crashkernel's memory being 472 * reserved, so do it here. 473 */ 474 reserve_crashkernel(); 475 476 memblock_dump_all(); 477 } 478 479 /* 480 * mem_init() marks the free areas in the mem_map and tells us how much memory 481 * is free. This is done after various parts of the system have claimed their 482 * memory after the kernel image. 483 */ 484 void __init mem_init(void) 485 { 486 if (swiotlb_force == SWIOTLB_FORCE || 487 max_pfn > PFN_DOWN(arm64_dma_phys_limit)) 488 swiotlb_init(1); 489 else 490 swiotlb_force = SWIOTLB_NO_FORCE; 491 492 set_max_mapnr(max_pfn - PHYS_PFN_OFFSET); 493 494 /* this will put all unused low memory onto the freelists */ 495 memblock_free_all(); 496 497 /* 498 * Check boundaries twice: Some fundamental inconsistencies can be 499 * detected at build time already. 500 */ 501 #ifdef CONFIG_COMPAT 502 BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64); 503 #endif 504 505 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { 506 extern int sysctl_overcommit_memory; 507 /* 508 * On a machine this small we won't get anywhere without 509 * overcommit, so turn it on by default. 510 */ 511 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; 512 } 513 } 514 515 void free_initmem(void) 516 { 517 free_reserved_area(lm_alias(__init_begin), 518 lm_alias(__init_end), 519 POISON_FREE_INITMEM, "unused kernel"); 520 /* 521 * Unmap the __init region but leave the VM area in place. This 522 * prevents the region from being reused for kernel modules, which 523 * is not supported by kallsyms. 524 */ 525 vunmap_range((u64)__init_begin, (u64)__init_end); 526 } 527 528 void dump_mem_limit(void) 529 { 530 if (memory_limit != PHYS_ADDR_MAX) { 531 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20); 532 } else { 533 pr_emerg("Memory Limit: none\n"); 534 } 535 } 536