2 * Based on arch/arm/mm/init.c
4 * Copyright (C) 1995-2005 Russell King
5 * Copyright (C) 2012 ARM Ltd.
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.
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.
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/>.
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>
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>
41 #include <linux/kexec.h>
42 #include <linux/crash_dump.h>
45 #include <asm/fixmap.h>
46 #include <asm/kasan.h>
47 #include <asm/kernel-pgtable.h>
48 #include <asm/memory.h>
50 #include <asm/sections.h>
51 #include <asm/setup.h>
52 #include <asm/sizes.h>
54 #include <asm/alternative.h>
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.
62 s64 memstart_addr __ro_after_init = -1;
63 phys_addr_t arm64_dma_phys_limit __ro_after_init;
65 #ifdef CONFIG_BLK_DEV_INITRD
66 static int __init early_initrd(char *p)
68 unsigned long start, size;
71 start = memparse(p, &endp);
73 size = memparse(endp + 1, NULL);
76 initrd_end = start + size;
80 early_param("initrd", early_initrd);
83 #ifdef CONFIG_KEXEC_CORE
85 * reserve_crashkernel() - reserves memory for crash kernel
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.
91 static void __init reserve_crashkernel(void)
93 unsigned long long crash_base, crash_size;
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)
102 crash_size = PAGE_ALIGN(crash_size);
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,
108 if (crash_base == 0) {
109 pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
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");
120 if (memblock_is_region_reserved(crash_base, crash_size)) {
121 pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n");
125 if (!IS_ALIGNED(crash_base, SZ_2M)) {
126 pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n");
130 memblock_reserve(crash_base, crash_size);
132 pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
133 crash_base, crash_base + crash_size, crash_size >> 20);
135 crashk_res.start = crash_base;
136 crashk_res.end = crash_base + crash_size - 1;
139 static void __init kexec_reserve_crashkres_pages(void)
141 #ifdef CONFIG_HIBERNATION
149 * To reduce the size of hibernation image, all the pages are
150 * marked as Reserved initially.
152 for (addr = crashk_res.start; addr < (crashk_res.end + 1);
154 page = phys_to_page(addr);
155 SetPageReserved(page);
160 static void __init reserve_crashkernel(void)
164 static void __init kexec_reserve_crashkres_pages(void)
167 #endif /* CONFIG_KEXEC_CORE */
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)
176 if (depth != 1 || strcmp(uname, "chosen") != 0)
179 reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
180 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells)))
183 elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, ®);
184 elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, ®);
190 * reserve_elfcorehdr() - reserves memory for elf core header
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.
197 static void __init reserve_elfcorehdr(void)
199 of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL);
201 if (!elfcorehdr_size)
204 if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
205 pr_warn("elfcorehdr is overlapped\n");
209 memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
211 pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n",
212 elfcorehdr_size >> 10, elfcorehdr_addr);
215 static void __init reserve_elfcorehdr(void)
218 #endif /* CONFIG_CRASH_DUMP */
220 * Return the maximum physical address for ZONE_DMA32 (DMA_BIT_MASK(32)). It
221 * currently assumes that for memory starting above 4G, 32-bit devices will
224 static phys_addr_t __init max_zone_dma_phys(void)
226 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
227 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
232 static void __init zone_sizes_init(unsigned long min, unsigned long max)
234 unsigned long max_zone_pfns[MAX_NR_ZONES] = {0};
236 if (IS_ENABLED(CONFIG_ZONE_DMA32))
237 max_zone_pfns[ZONE_DMA32] = PFN_DOWN(max_zone_dma_phys());
238 max_zone_pfns[ZONE_NORMAL] = max;
240 free_area_init_nodes(max_zone_pfns);
245 static void __init zone_sizes_init(unsigned long min, unsigned long max)
247 struct memblock_region *reg;
248 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
249 unsigned long max_dma = min;
251 memset(zone_size, 0, sizeof(zone_size));
253 /* 4GB maximum for 32-bit only capable devices */
254 #ifdef CONFIG_ZONE_DMA32
255 max_dma = PFN_DOWN(arm64_dma_phys_limit);
256 zone_size[ZONE_DMA32] = max_dma - min;
258 zone_size[ZONE_NORMAL] = max - max_dma;
260 memcpy(zhole_size, zone_size, sizeof(zhole_size));
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);
269 #ifdef CONFIG_ZONE_DMA32
270 if (start < max_dma) {
271 unsigned long dma_end = min(end, max_dma);
272 zhole_size[ZONE_DMA32] -= dma_end - start;
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;
282 free_area_init_node(0, zone_size, min, zhole_size);
285 #endif /* CONFIG_NUMA */
287 int pfn_valid(unsigned long pfn)
289 phys_addr_t addr = pfn << PAGE_SHIFT;
291 if ((addr >> PAGE_SHIFT) != pfn)
293 return memblock_is_map_memory(addr);
295 EXPORT_SYMBOL(pfn_valid);
297 #ifndef CONFIG_SPARSEMEM
298 static void __init arm64_memory_present(void)
302 static void __init arm64_memory_present(void)
304 struct memblock_region *reg;
306 for_each_memblock(memory, reg) {
307 int nid = memblock_get_region_node(reg);
309 memory_present(nid, memblock_region_memory_base_pfn(reg),
310 memblock_region_memory_end_pfn(reg));
315 static phys_addr_t memory_limit = PHYS_ADDR_MAX;
318 * Limit the memory size that was specified via FDT.
320 static int __init early_mem(char *p)
325 memory_limit = memparse(p, &p) & PAGE_MASK;
326 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
330 early_param("mem", early_mem);
332 static int __init early_init_dt_scan_usablemem(unsigned long node,
333 const char *uname, int depth, void *data)
335 struct memblock_region *usablemem = data;
339 if (depth != 1 || strcmp(uname, "chosen") != 0)
342 reg = of_get_flat_dt_prop(node, "linux,usable-memory-range", &len);
343 if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells)))
346 usablemem->base = dt_mem_next_cell(dt_root_addr_cells, ®);
347 usablemem->size = dt_mem_next_cell(dt_root_size_cells, ®);
352 static void __init fdt_enforce_memory_region(void)
354 struct memblock_region reg = {
358 of_scan_flat_dt(early_init_dt_scan_usablemem, ®);
361 memblock_cap_memory_range(reg.base, reg.size);
364 void __init arm64_memblock_init(void)
366 const s64 linear_region_size = -(s64)PAGE_OFFSET;
368 /* Handle linux,usable-memory-range property */
369 fdt_enforce_memory_region();
371 /* Remove memory above our supported physical address size */
372 memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX);
375 * Ensure that the linear region takes up exactly half of the kernel
376 * virtual address space. This way, we can distinguish a linear address
377 * from a kernel/module/vmalloc address by testing a single bit.
379 BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1));
382 * Select a suitable value for the base of physical memory.
384 memstart_addr = round_down(memblock_start_of_DRAM(),
385 ARM64_MEMSTART_ALIGN);
388 * Remove the memory that we will not be able to cover with the
389 * linear mapping. Take care not to clip the kernel which may be
392 memblock_remove(max_t(u64, memstart_addr + linear_region_size,
393 __pa_symbol(_end)), ULLONG_MAX);
394 if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) {
395 /* ensure that memstart_addr remains sufficiently aligned */
396 memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size,
397 ARM64_MEMSTART_ALIGN);
398 memblock_remove(0, memstart_addr);
402 * Apply the memory limit if it was set. Since the kernel may be loaded
403 * high up in memory, add back the kernel region that must be accessible
404 * via the linear mapping.
406 if (memory_limit != PHYS_ADDR_MAX) {
407 memblock_mem_limit_remove_map(memory_limit);
408 memblock_add(__pa_symbol(_text), (u64)(_end - _text));
411 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_start) {
413 * Add back the memory we just removed if it results in the
414 * initrd to become inaccessible via the linear mapping.
415 * Otherwise, this is a no-op
417 u64 base = initrd_start & PAGE_MASK;
418 u64 size = PAGE_ALIGN(initrd_end) - base;
421 * We can only add back the initrd memory if we don't end up
422 * with more memory than we can address via the linear mapping.
423 * It is up to the bootloader to position the kernel and the
424 * initrd reasonably close to each other (i.e., within 32 GB of
425 * each other) so that all granule/#levels combinations can
426 * always access both.
428 if (WARN(base < memblock_start_of_DRAM() ||
429 base + size > memblock_start_of_DRAM() +
431 "initrd not fully accessible via the linear mapping -- please check your bootloader ...\n")) {
434 memblock_remove(base, size); /* clear MEMBLOCK_ flags */
435 memblock_add(base, size);
436 memblock_reserve(base, size);
440 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
441 extern u16 memstart_offset_seed;
442 u64 range = linear_region_size -
443 (memblock_end_of_DRAM() - memblock_start_of_DRAM());
446 * If the size of the linear region exceeds, by a sufficient
447 * margin, the size of the region that the available physical
448 * memory spans, randomize the linear region as well.
450 if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
451 range = range / ARM64_MEMSTART_ALIGN + 1;
452 memstart_addr -= ARM64_MEMSTART_ALIGN *
453 ((range * memstart_offset_seed) >> 16);
458 * Register the kernel text, kernel data, initrd, and initial
459 * pagetables with memblock.
461 memblock_reserve(__pa_symbol(_text), _end - _text);
462 #ifdef CONFIG_BLK_DEV_INITRD
464 memblock_reserve(initrd_start, initrd_end - initrd_start);
466 /* the generic initrd code expects virtual addresses */
467 initrd_start = __phys_to_virt(initrd_start);
468 initrd_end = __phys_to_virt(initrd_end);
472 early_init_fdt_scan_reserved_mem();
474 /* 4GB maximum for 32-bit only capable devices */
475 if (IS_ENABLED(CONFIG_ZONE_DMA32))
476 arm64_dma_phys_limit = max_zone_dma_phys();
478 arm64_dma_phys_limit = PHYS_MASK + 1;
480 reserve_crashkernel();
482 reserve_elfcorehdr();
484 high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
486 dma_contiguous_reserve(arm64_dma_phys_limit);
488 memblock_allow_resize();
491 void __init bootmem_init(void)
493 unsigned long min, max;
495 min = PFN_UP(memblock_start_of_DRAM());
496 max = PFN_DOWN(memblock_end_of_DRAM());
498 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
500 max_pfn = max_low_pfn = max;
504 * Sparsemem tries to allocate bootmem in memory_present(), so must be
505 * done after the fixed reservations.
507 arm64_memory_present();
510 zone_sizes_init(min, max);
515 #ifndef CONFIG_SPARSEMEM_VMEMMAP
516 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
518 struct page *start_pg, *end_pg;
519 unsigned long pg, pgend;
522 * Convert start_pfn/end_pfn to a struct page pointer.
524 start_pg = pfn_to_page(start_pfn - 1) + 1;
525 end_pg = pfn_to_page(end_pfn - 1) + 1;
528 * Convert to physical addresses, and round start upwards and end
531 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
532 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
535 * If there are free pages between these, free the section of the
539 free_bootmem(pg, pgend - pg);
543 * The mem_map array can get very big. Free the unused area of the memory map.
545 static void __init free_unused_memmap(void)
547 unsigned long start, prev_end = 0;
548 struct memblock_region *reg;
550 for_each_memblock(memory, reg) {
551 start = __phys_to_pfn(reg->base);
553 #ifdef CONFIG_SPARSEMEM
555 * Take care not to free memmap entries that don't exist due
556 * to SPARSEMEM sections which aren't present.
558 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
561 * If we had a previous bank, and there is a space between the
562 * current bank and the previous, free it.
564 if (prev_end && prev_end < start)
565 free_memmap(prev_end, start);
568 * Align up here since the VM subsystem insists that the
569 * memmap entries are valid from the bank end aligned to
570 * MAX_ORDER_NR_PAGES.
572 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
576 #ifdef CONFIG_SPARSEMEM
577 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
578 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
581 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
584 * mem_init() marks the free areas in the mem_map and tells us how much memory
585 * is free. This is done after various parts of the system have claimed their
586 * memory after the kernel image.
588 void __init mem_init(void)
590 if (swiotlb_force == SWIOTLB_FORCE ||
591 max_pfn > (arm64_dma_phys_limit >> PAGE_SHIFT))
594 swiotlb_force = SWIOTLB_NO_FORCE;
596 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
598 #ifndef CONFIG_SPARSEMEM_VMEMMAP
599 free_unused_memmap();
601 /* this will put all unused low memory onto the freelists */
604 kexec_reserve_crashkres_pages();
606 mem_init_print_info(NULL);
609 * Check boundaries twice: Some fundamental inconsistencies can be
610 * detected at build time already.
613 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
616 #ifdef CONFIG_SPARSEMEM_VMEMMAP
618 * Make sure we chose the upper bound of sizeof(struct page)
619 * correctly when sizing the VMEMMAP array.
621 BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT));
624 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
625 extern int sysctl_overcommit_memory;
627 * On a machine this small we won't get anywhere without
628 * overcommit, so turn it on by default.
630 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
634 void free_initmem(void)
636 free_reserved_area(lm_alias(__init_begin),
637 lm_alias(__init_end),
640 * Unmap the __init region but leave the VM area in place. This
641 * prevents the region from being reused for kernel modules, which
642 * is not supported by kallsyms.
644 unmap_kernel_range((u64)__init_begin, (u64)(__init_end - __init_begin));
647 #ifdef CONFIG_BLK_DEV_INITRD
649 static int keep_initrd __initdata;
651 void __init free_initrd_mem(unsigned long start, unsigned long end)
654 free_reserved_area((void *)start, (void *)end, 0, "initrd");
655 memblock_free(__virt_to_phys(start), end - start);
659 static int __init keepinitrd_setup(char *__unused)
665 __setup("keepinitrd", keepinitrd_setup);
669 * Dump out memory limit information on panic.
671 static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
673 if (memory_limit != PHYS_ADDR_MAX) {
674 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
676 pr_emerg("Memory Limit: none\n");
681 static struct notifier_block mem_limit_notifier = {
682 .notifier_call = dump_mem_limit,
685 static int __init register_mem_limit_dumper(void)
687 atomic_notifier_chain_register(&panic_notifier_list,
688 &mem_limit_notifier);
691 __initcall(register_mem_limit_dumper);