1 /* 2 * Based on arch/arm/mm/init.c 3 * 4 * Copyright (C) 1995-2005 Russell King 5 * Copyright (C) 2012 ARM Ltd. 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/export.h> 22 #include <linux/errno.h> 23 #include <linux/swap.h> 24 #include <linux/init.h> 25 #include <linux/bootmem.h> 26 #include <linux/cache.h> 27 #include <linux/mman.h> 28 #include <linux/nodemask.h> 29 #include <linux/initrd.h> 30 #include <linux/gfp.h> 31 #include <linux/memblock.h> 32 #include <linux/sort.h> 33 #include <linux/of.h> 34 #include <linux/of_fdt.h> 35 #include <linux/dma-mapping.h> 36 #include <linux/dma-contiguous.h> 37 #include <linux/efi.h> 38 #include <linux/swiotlb.h> 39 #include <linux/vmalloc.h> 40 #include <linux/mm.h> 41 #include <linux/kexec.h> 42 #include <linux/crash_dump.h> 43 44 #include <asm/boot.h> 45 #include <asm/fixmap.h> 46 #include <asm/kasan.h> 47 #include <asm/kernel-pgtable.h> 48 #include <asm/memory.h> 49 #include <asm/numa.h> 50 #include <asm/sections.h> 51 #include <asm/setup.h> 52 #include <asm/sizes.h> 53 #include <asm/tlb.h> 54 #include <asm/alternative.h> 55 56 /* 57 * We need to be able to catch inadvertent references to memstart_addr 58 * that occur (potentially in generic code) before arm64_memblock_init() 59 * executes, which assigns it its actual value. So use a default value 60 * that cannot be mistaken for a real physical address. 61 */ 62 s64 memstart_addr __ro_after_init = -1; 63 phys_addr_t arm64_dma_phys_limit __ro_after_init; 64 65 #ifdef CONFIG_BLK_DEV_INITRD 66 static int __init early_initrd(char *p) 67 { 68 unsigned long start, size; 69 char *endp; 70 71 start = memparse(p, &endp); 72 if (*endp == ',') { 73 size = memparse(endp + 1, NULL); 74 75 initrd_start = start; 76 initrd_end = start + size; 77 } 78 return 0; 79 } 80 early_param("initrd", early_initrd); 81 #endif 82 83 #ifdef CONFIG_KEXEC_CORE 84 /* 85 * reserve_crashkernel() - reserves memory for crash kernel 86 * 87 * This function reserves memory area given in "crashkernel=" kernel command 88 * line parameter. The memory reserved is used by dump capture kernel when 89 * primary kernel is crashing. 90 */ 91 static void __init reserve_crashkernel(void) 92 { 93 unsigned long long crash_base, crash_size; 94 int ret; 95 96 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 97 &crash_size, &crash_base); 98 /* no crashkernel= or invalid value specified */ 99 if (ret || !crash_size) 100 return; 101 102 crash_size = PAGE_ALIGN(crash_size); 103 104 if (crash_base == 0) { 105 /* Current arm64 boot protocol requires 2MB alignment */ 106 crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT, 107 crash_size, SZ_2M); 108 if (crash_base == 0) { 109 pr_warn("cannot allocate crashkernel (size:0x%llx)\n", 110 crash_size); 111 return; 112 } 113 } else { 114 /* User specifies base address explicitly. */ 115 if (!memblock_is_region_memory(crash_base, crash_size)) { 116 pr_warn("cannot reserve crashkernel: region is not memory\n"); 117 return; 118 } 119 120 if (memblock_is_region_reserved(crash_base, crash_size)) { 121 pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n"); 122 return; 123 } 124 125 if (!IS_ALIGNED(crash_base, SZ_2M)) { 126 pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n"); 127 return; 128 } 129 } 130 memblock_reserve(crash_base, crash_size); 131 132 pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", 133 crash_base, crash_base + crash_size, crash_size >> 20); 134 135 crashk_res.start = crash_base; 136 crashk_res.end = crash_base + crash_size - 1; 137 } 138 139 static void __init kexec_reserve_crashkres_pages(void) 140 { 141 #ifdef CONFIG_HIBERNATION 142 phys_addr_t addr; 143 struct page *page; 144 145 if (!crashk_res.end) 146 return; 147 148 /* 149 * To reduce the size of hibernation image, all the pages are 150 * marked as Reserved initially. 151 */ 152 for (addr = crashk_res.start; addr < (crashk_res.end + 1); 153 addr += PAGE_SIZE) { 154 page = phys_to_page(addr); 155 SetPageReserved(page); 156 } 157 #endif 158 } 159 #else 160 static void __init reserve_crashkernel(void) 161 { 162 } 163 164 static void __init kexec_reserve_crashkres_pages(void) 165 { 166 } 167 #endif /* CONFIG_KEXEC_CORE */ 168 169 #ifdef CONFIG_CRASH_DUMP 170 static int __init early_init_dt_scan_elfcorehdr(unsigned long node, 171 const char *uname, int depth, void *data) 172 { 173 const __be32 *reg; 174 int len; 175 176 if (depth != 1 || strcmp(uname, "chosen") != 0) 177 return 0; 178 179 reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); 180 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) 181 return 1; 182 183 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, ®); 184 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, ®); 185 186 return 1; 187 } 188 189 /* 190 * reserve_elfcorehdr() - reserves memory for elf core header 191 * 192 * This function reserves the memory occupied by an elf core header 193 * described in the device tree. This region contains all the 194 * information about primary kernel's core image and is used by a dump 195 * capture kernel to access the system memory on primary kernel. 196 */ 197 static void __init reserve_elfcorehdr(void) 198 { 199 of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL); 200 201 if (!elfcorehdr_size) 202 return; 203 204 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { 205 pr_warn("elfcorehdr is overlapped\n"); 206 return; 207 } 208 209 memblock_reserve(elfcorehdr_addr, elfcorehdr_size); 210 211 pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n", 212 elfcorehdr_size >> 10, elfcorehdr_addr); 213 } 214 #else 215 static void __init reserve_elfcorehdr(void) 216 { 217 } 218 #endif /* CONFIG_CRASH_DUMP */ 219 /* 220 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It 221 * currently assumes that for memory starting above 4G, 32-bit devices will 222 * use a DMA offset. 223 */ 224 static phys_addr_t __init max_zone_dma_phys(void) 225 { 226 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32); 227 return min(offset + (1ULL << 32), memblock_end_of_DRAM()); 228 } 229 230 #ifdef CONFIG_NUMA 231 232 static void __init zone_sizes_init(unsigned long min, unsigned long max) 233 { 234 unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; 235 236 if (IS_ENABLED(CONFIG_ZONE_DMA)) 237 max_zone_pfns[ZONE_DMA] = PFN_DOWN(max_zone_dma_phys()); 238 max_zone_pfns[ZONE_NORMAL] = max; 239 240 free_area_init_nodes(max_zone_pfns); 241 } 242 243 #else 244 245 static void __init zone_sizes_init(unsigned long min, unsigned long max) 246 { 247 struct memblock_region *reg; 248 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES]; 249 unsigned long max_dma = min; 250 251 memset(zone_size, 0, sizeof(zone_size)); 252 253 /* 4GB maximum for 32-bit only capable devices */ 254 #ifdef CONFIG_ZONE_DMA 255 max_dma = PFN_DOWN(arm64_dma_phys_limit); 256 zone_size[ZONE_DMA] = max_dma - min; 257 #endif 258 zone_size[ZONE_NORMAL] = max - max_dma; 259 260 memcpy(zhole_size, zone_size, sizeof(zhole_size)); 261 262 for_each_memblock(memory, reg) { 263 unsigned long start = memblock_region_memory_base_pfn(reg); 264 unsigned long end = memblock_region_memory_end_pfn(reg); 265 266 if (start >= max) 267 continue; 268 269 #ifdef CONFIG_ZONE_DMA 270 if (start < max_dma) { 271 unsigned long dma_end = min(end, max_dma); 272 zhole_size[ZONE_DMA] -= dma_end - start; 273 } 274 #endif 275 if (end > max_dma) { 276 unsigned long normal_end = min(end, max); 277 unsigned long normal_start = max(start, max_dma); 278 zhole_size[ZONE_NORMAL] -= normal_end - normal_start; 279 } 280 } 281 282 free_area_init_node(0, zone_size, min, zhole_size); 283 } 284 285 #endif /* CONFIG_NUMA */ 286 287 #ifdef CONFIG_HAVE_ARCH_PFN_VALID 288 int pfn_valid(unsigned long pfn) 289 { 290 return memblock_is_map_memory(pfn << PAGE_SHIFT); 291 } 292 EXPORT_SYMBOL(pfn_valid); 293 #endif 294 295 #ifndef CONFIG_SPARSEMEM 296 static void __init arm64_memory_present(void) 297 { 298 } 299 #else 300 static void __init arm64_memory_present(void) 301 { 302 struct memblock_region *reg; 303 304 for_each_memblock(memory, reg) { 305 int nid = memblock_get_region_node(reg); 306 307 memory_present(nid, memblock_region_memory_base_pfn(reg), 308 memblock_region_memory_end_pfn(reg)); 309 } 310 } 311 #endif 312 313 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX; 314 315 /* 316 * Limit the memory size that was specified via FDT. 317 */ 318 static int __init early_mem(char *p) 319 { 320 if (!p) 321 return 1; 322 323 memory_limit = memparse(p, &p) & PAGE_MASK; 324 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20); 325 326 return 0; 327 } 328 early_param("mem", early_mem); 329 330 static int __init early_init_dt_scan_usablemem(unsigned long node, 331 const char *uname, int depth, void *data) 332 { 333 struct memblock_region *usablemem = data; 334 const __be32 *reg; 335 int len; 336 337 if (depth != 1 || strcmp(uname, "chosen") != 0) 338 return 0; 339 340 reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len); 341 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) 342 return 1; 343 344 usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®); 345 usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®); 346 347 return 1; 348 } 349 350 static void __init fdt_enforce_memory_region(void) 351 { 352 struct memblock_region reg = { 353 .size = 0, 354 }; 355 356 of_scan_flat_dt(early_init_dt_scan_usablemem, ®); 357 358 if (reg.size) 359 memblock_cap_memory_range(reg.base, reg.size); 360 } 361 362 void __init arm64_memblock_init(void) 363 { 364 const s64 linear_region_size = -(s64)PAGE_OFFSET; 365 366 /* Handle linux,usable-memory-range property */ 367 fdt_enforce_memory_region(); 368 369 /* 370 * Ensure that the linear region takes up exactly half of the kernel 371 * virtual address space. This way, we can distinguish a linear address 372 * from a kernel/module/vmalloc address by testing a single bit. 373 */ 374 BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1)); 375 376 /* 377 * Select a suitable value for the base of physical memory. 378 */ 379 memstart_addr = round_down(memblock_start_of_DRAM(), 380 ARM64_MEMSTART_ALIGN); 381 382 /* 383 * Remove the memory that we will not be able to cover with the 384 * linear mapping. Take care not to clip the kernel which may be 385 * high in memory. 386 */ 387 memblock_remove(max_t(u64, memstart_addr + linear_region_size, 388 __pa_symbol(_end)), ULLONG_MAX); 389 if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) { 390 /* ensure that memstart_addr remains sufficiently aligned */ 391 memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size, 392 ARM64_MEMSTART_ALIGN); 393 memblock_remove(0, memstart_addr); 394 } 395 396 /* 397 * Apply the memory limit if it was set. Since the kernel may be loaded 398 * high up in memory, add back the kernel region that must be accessible 399 * via the linear mapping. 400 */ 401 if (memory_limit != (phys_addr_t)ULLONG_MAX) { 402 memblock_mem_limit_remove_map(memory_limit); 403 memblock_add(__pa_symbol(_text), (u64)(_end - _text)); 404 } 405 406 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) { 407 /* 408 * Add back the memory we just removed if it results in the 409 * initrd to become inaccessible via the linear mapping. 410 * Otherwise, this is a no-op 411 */ 412 u64 base = initrd_start & PAGE_MASK; 413 u64 size = PAGE_ALIGN(initrd_end) - base; 414 415 /* 416 * We can only add back the initrd memory if we don't end up 417 * with more memory than we can address via the linear mapping. 418 * It is up to the bootloader to position the kernel and the 419 * initrd reasonably close to each other (i.e., within 32 GB of 420 * each other) so that all granule/#levels combinations can 421 * always access both. 422 */ 423 if (WARN(base < memblock_start_of_DRAM() || 424 base + size > memblock_start_of_DRAM() + 425 linear_region_size, 426 "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) { 427 initrd_start = 0; 428 } else { 429 memblock_remove(base, size); /* clear MEMBLOCK_ flags */ 430 memblock_add(base, size); 431 memblock_reserve(base, size); 432 } 433 } 434 435 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { 436 extern u16 memstart_offset_seed; 437 u64 range = linear_region_size - 438 (memblock_end_of_DRAM() - memblock_start_of_DRAM()); 439 440 /* 441 * If the size of the linear region exceeds, by a sufficient 442 * margin, the size of the region that the available physical 443 * memory spans, randomize the linear region as well. 444 */ 445 if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) { 446 range = range / ARM64_MEMSTART_ALIGN + 1; 447 memstart_addr -= ARM64_MEMSTART_ALIGN * 448 ((range * memstart_offset_seed) >> 16); 449 } 450 } 451 452 /* 453 * Register the kernel text, kernel data, initrd, and initial 454 * pagetables with memblock. 455 */ 456 memblock_reserve(__pa_symbol(_text), _end - _text); 457 #ifdef CONFIG_BLK_DEV_INITRD 458 if (initrd_start) { 459 memblock_reserve(initrd_start, initrd_end - initrd_start); 460 461 /* the generic initrd code expects virtual addresses */ 462 initrd_start = __phys_to_virt(initrd_start); 463 initrd_end = __phys_to_virt(initrd_end); 464 } 465 #endif 466 467 early_init_fdt_scan_reserved_mem(); 468 469 /* 4GB maximum for 32-bit only capable devices */ 470 if (IS_ENABLED(CONFIG_ZONE_DMA)) 471 arm64_dma_phys_limit = max_zone_dma_phys(); 472 else 473 arm64_dma_phys_limit = PHYS_MASK + 1; 474 475 reserve_crashkernel(); 476 477 reserve_elfcorehdr(); 478 479 dma_contiguous_reserve(arm64_dma_phys_limit); 480 481 memblock_allow_resize(); 482 } 483 484 void __init bootmem_init(void) 485 { 486 unsigned long min, max; 487 488 min = PFN_UP(memblock_start_of_DRAM()); 489 max = PFN_DOWN(memblock_end_of_DRAM()); 490 491 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT); 492 493 max_pfn = max_low_pfn = max; 494 495 arm64_numa_init(); 496 /* 497 * Sparsemem tries to allocate bootmem in memory_present(), so must be 498 * done after the fixed reservations. 499 */ 500 arm64_memory_present(); 501 502 sparse_init(); 503 zone_sizes_init(min, max); 504 505 high_memory = __va((max << PAGE_SHIFT) - 1) + 1; 506 memblock_dump_all(); 507 } 508 509 #ifndef CONFIG_SPARSEMEM_VMEMMAP 510 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn) 511 { 512 struct page *start_pg, *end_pg; 513 unsigned long pg, pgend; 514 515 /* 516 * Convert start_pfn/end_pfn to a struct page pointer. 517 */ 518 start_pg = pfn_to_page(start_pfn - 1) + 1; 519 end_pg = pfn_to_page(end_pfn - 1) + 1; 520 521 /* 522 * Convert to physical addresses, and round start upwards and end 523 * downwards. 524 */ 525 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg)); 526 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK; 527 528 /* 529 * If there are free pages between these, free the section of the 530 * memmap array. 531 */ 532 if (pg < pgend) 533 free_bootmem(pg, pgend - pg); 534 } 535 536 /* 537 * The mem_map array can get very big. Free the unused area of the memory map. 538 */ 539 static void __init free_unused_memmap(void) 540 { 541 unsigned long start, prev_end = 0; 542 struct memblock_region *reg; 543 544 for_each_memblock(memory, reg) { 545 start = __phys_to_pfn(reg->base); 546 547 #ifdef CONFIG_SPARSEMEM 548 /* 549 * Take care not to free memmap entries that don't exist due 550 * to SPARSEMEM sections which aren't present. 551 */ 552 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION)); 553 #endif 554 /* 555 * If we had a previous bank, and there is a space between the 556 * current bank and the previous, free it. 557 */ 558 if (prev_end && prev_end < start) 559 free_memmap(prev_end, start); 560 561 /* 562 * Align up here since the VM subsystem insists that the 563 * memmap entries are valid from the bank end aligned to 564 * MAX_ORDER_NR_PAGES. 565 */ 566 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size), 567 MAX_ORDER_NR_PAGES); 568 } 569 570 #ifdef CONFIG_SPARSEMEM 571 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) 572 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION)); 573 #endif 574 } 575 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 576 577 /* 578 * mem_init() marks the free areas in the mem_map and tells us how much memory 579 * is free. This is done after various parts of the system have claimed their 580 * memory after the kernel image. 581 */ 582 void __init mem_init(void) 583 { 584 if (swiotlb_force == SWIOTLB_FORCE || 585 max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT)) 586 swiotlb_init(1); 587 else 588 swiotlb_force = SWIOTLB_NO_FORCE; 589 590 set_max_mapnr(pfn_to_page(max_pfn) - mem_map); 591 592 #ifndef CONFIG_SPARSEMEM_VMEMMAP 593 free_unused_memmap(); 594 #endif 595 /* this will put all unused low memory onto the freelists */ 596 free_all_bootmem(); 597 598 kexec_reserve_crashkres_pages(); 599 600 mem_init_print_info(NULL); 601 602 #define MLK(b, t) b, t, ((t) - (b)) >> 10 603 #define MLM(b, t) b, t, ((t) - (b)) >> 20 604 #define MLG(b, t) b, t, ((t) - (b)) >> 30 605 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K) 606 607 pr_notice("Virtual kernel memory layout:\n"); 608 #ifdef CONFIG_KASAN 609 pr_notice(" kasan : 0x%16lx - 0x%16lx (%6ld GB)\n", 610 MLG(KASAN_SHADOW_START, KASAN_SHADOW_END)); 611 #endif 612 pr_notice(" modules : 0x%16lx - 0x%16lx (%6ld MB)\n", 613 MLM(MODULES_VADDR, MODULES_END)); 614 pr_notice(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n", 615 MLG(VMALLOC_START, VMALLOC_END)); 616 pr_notice(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n", 617 MLK_ROUNDUP(_text, _etext)); 618 pr_notice(" .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n", 619 MLK_ROUNDUP(__start_rodata, __init_begin)); 620 pr_notice(" .init : 0x%p" " - 0x%p" " (%6ld KB)\n", 621 MLK_ROUNDUP(__init_begin, __init_end)); 622 pr_notice(" .data : 0x%p" " - 0x%p" " (%6ld KB)\n", 623 MLK_ROUNDUP(_sdata, _edata)); 624 pr_notice(" .bss : 0x%p" " - 0x%p" " (%6ld KB)\n", 625 MLK_ROUNDUP(__bss_start, __bss_stop)); 626 pr_notice(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n", 627 MLK(FIXADDR_START, FIXADDR_TOP)); 628 pr_notice(" PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n", 629 MLM(PCI_IO_START, PCI_IO_END)); 630 #ifdef CONFIG_SPARSEMEM_VMEMMAP 631 pr_notice(" vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n", 632 MLG(VMEMMAP_START, VMEMMAP_START + VMEMMAP_SIZE)); 633 pr_notice(" 0x%16lx - 0x%16lx (%6ld MB actual)\n", 634 MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()), 635 (unsigned long)virt_to_page(high_memory))); 636 #endif 637 pr_notice(" memory : 0x%16lx - 0x%16lx (%6ld MB)\n", 638 MLM(__phys_to_virt(memblock_start_of_DRAM()), 639 (unsigned long)high_memory)); 640 641 #undef MLK 642 #undef MLM 643 #undef MLK_ROUNDUP 644 645 /* 646 * Check boundaries twice: Some fundamental inconsistencies can be 647 * detected at build time already. 648 */ 649 #ifdef CONFIG_COMPAT 650 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64); 651 #endif 652 653 /* 654 * Make sure we chose the upper bound of sizeof(struct page) 655 * correctly. 656 */ 657 BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT)); 658 659 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { 660 extern int sysctl_overcommit_memory; 661 /* 662 * On a machine this small we won't get anywhere without 663 * overcommit, so turn it on by default. 664 */ 665 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS; 666 } 667 } 668 669 void free_initmem(void) 670 { 671 free_reserved_area(lm_alias(__init_begin), 672 lm_alias(__init_end), 673 0, "unused kernel"); 674 /* 675 * Unmap the __init region but leave the VM area in place. This 676 * prevents the region from being reused for kernel modules, which 677 * is not supported by kallsyms. 678 */ 679 unmap_kernel_range((u64)__init_begin, (u64)(__init_end - __init_begin)); 680 } 681 682 #ifdef CONFIG_BLK_DEV_INITRD 683 684 static int keep_initrd __initdata; 685 686 void __init free_initrd_mem(unsigned long start, unsigned long end) 687 { 688 if (!keep_initrd) 689 free_reserved_area((void *)start, (void *)end, 0, "initrd"); 690 } 691 692 static int __init keepinitrd_setup(char *__unused) 693 { 694 keep_initrd = 1; 695 return 1; 696 } 697 698 __setup("keepinitrd", keepinitrd_setup); 699 #endif 700 701 /* 702 * Dump out memory limit information on panic. 703 */ 704 static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p) 705 { 706 if (memory_limit != (phys_addr_t)ULLONG_MAX) { 707 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20); 708 } else { 709 pr_emerg("Memory Limit: none\n"); 710 } 711 return 0; 712 } 713 714 static struct notifier_block mem_limit_notifier = { 715 .notifier_call = dump_mem_limit, 716 }; 717 718 static int __init register_mem_limit_dumper(void) 719 { 720 atomic_notifier_chain_register(&panic_notifier_list, 721 &mem_limit_notifier); 722 return 0; 723 } 724 __initcall(register_mem_limit_dumper); 725