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/mman.h>
27 #include <linux/nodemask.h>
28 #include <linux/initrd.h>
29 #include <linux/gfp.h>
30 #include <linux/memblock.h>
31 #include <linux/sort.h>
32 #include <linux/of_fdt.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/dma-contiguous.h>
35 #include <linux/efi.h>
36 #include <linux/swiotlb.h>
39 #include <asm/fixmap.h>
40 #include <asm/kasan.h>
41 #include <asm/kernel-pgtable.h>
42 #include <asm/memory.h>
43 #include <asm/sections.h>
44 #include <asm/setup.h>
45 #include <asm/sizes.h>
47 #include <asm/alternative.h>
52 * We need to be able to catch inadvertent references to memstart_addr
53 * that occur (potentially in generic code) before arm64_memblock_init()
54 * executes, which assigns it its actual value. So use a default value
55 * that cannot be mistaken for a real physical address.
57 s64 memstart_addr __read_mostly = -1;
58 phys_addr_t arm64_dma_phys_limit __read_mostly;
60 #ifdef CONFIG_BLK_DEV_INITRD
61 static int __init early_initrd(char *p)
63 unsigned long start, size;
66 start = memparse(p, &endp);
68 size = memparse(endp + 1, NULL);
71 initrd_end = start + size;
75 early_param("initrd", early_initrd);
79 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
80 * currently assumes that for memory starting above 4G, 32-bit devices will
83 static phys_addr_t __init max_zone_dma_phys(void)
85 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
86 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
89 static void __init zone_sizes_init(unsigned long min, unsigned long max)
91 struct memblock_region *reg;
92 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
93 unsigned long max_dma = min;
95 memset(zone_size, 0, sizeof(zone_size));
97 /* 4GB maximum for 32-bit only capable devices */
98 #ifdef CONFIG_ZONE_DMA
99 max_dma = PFN_DOWN(arm64_dma_phys_limit);
100 zone_size[ZONE_DMA] = max_dma - min;
102 zone_size[ZONE_NORMAL] = max - max_dma;
104 memcpy(zhole_size, zone_size, sizeof(zhole_size));
106 for_each_memblock(memory, reg) {
107 unsigned long start = memblock_region_memory_base_pfn(reg);
108 unsigned long end = memblock_region_memory_end_pfn(reg);
113 #ifdef CONFIG_ZONE_DMA
114 if (start < max_dma) {
115 unsigned long dma_end = min(end, max_dma);
116 zhole_size[ZONE_DMA] -= dma_end - start;
120 unsigned long normal_end = min(end, max);
121 unsigned long normal_start = max(start, max_dma);
122 zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
126 free_area_init_node(0, zone_size, min, zhole_size);
129 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
130 #define PFN_MASK ((1UL << (64 - PAGE_SHIFT)) - 1)
132 int pfn_valid(unsigned long pfn)
134 return (pfn & PFN_MASK) == pfn && memblock_is_map_memory(pfn << PAGE_SHIFT);
136 EXPORT_SYMBOL(pfn_valid);
139 #ifndef CONFIG_SPARSEMEM
140 static void __init arm64_memory_present(void)
144 static void __init arm64_memory_present(void)
146 struct memblock_region *reg;
148 for_each_memblock(memory, reg)
149 memory_present(0, memblock_region_memory_base_pfn(reg),
150 memblock_region_memory_end_pfn(reg));
154 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
157 * Limit the memory size that was specified via FDT.
159 static int __init early_mem(char *p)
164 memory_limit = memparse(p, &p) & PAGE_MASK;
165 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
169 early_param("mem", early_mem);
171 void __init arm64_memblock_init(void)
173 const s64 linear_region_size = -(s64)PAGE_OFFSET;
176 * Ensure that the linear region takes up exactly half of the kernel
177 * virtual address space. This way, we can distinguish a linear address
178 * from a kernel/module/vmalloc address by testing a single bit.
180 BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1));
183 * Select a suitable value for the base of physical memory.
185 memstart_addr = round_down(memblock_start_of_DRAM(),
186 ARM64_MEMSTART_ALIGN);
189 * Remove the memory that we will not be able to cover with the
190 * linear mapping. Take care not to clip the kernel which may be
193 memblock_remove(max_t(u64, memstart_addr + linear_region_size, __pa(_end)),
195 if (memstart_addr + linear_region_size < memblock_end_of_DRAM()) {
196 /* ensure that memstart_addr remains sufficiently aligned */
197 memstart_addr = round_up(memblock_end_of_DRAM() - linear_region_size,
198 ARM64_MEMSTART_ALIGN);
199 memblock_remove(0, memstart_addr);
203 * Apply the memory limit if it was set. Since the kernel may be loaded
204 * high up in memory, add back the kernel region that must be accessible
205 * via the linear mapping.
207 if (memory_limit != (phys_addr_t)ULLONG_MAX) {
208 memblock_enforce_memory_limit(memory_limit);
209 memblock_add(__pa(_text), (u64)(_end - _text));
212 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
213 extern u16 memstart_offset_seed;
214 u64 range = linear_region_size -
215 (memblock_end_of_DRAM() - memblock_start_of_DRAM());
218 * If the size of the linear region exceeds, by a sufficient
219 * margin, the size of the region that the available physical
220 * memory spans, randomize the linear region as well.
222 if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
223 range = range / ARM64_MEMSTART_ALIGN + 1;
224 memstart_addr -= ARM64_MEMSTART_ALIGN *
225 ((range * memstart_offset_seed) >> 16);
230 * Register the kernel text, kernel data, initrd, and initial
231 * pagetables with memblock.
233 memblock_reserve(__pa(_text), _end - _text);
234 #ifdef CONFIG_BLK_DEV_INITRD
236 memblock_reserve(initrd_start, initrd_end - initrd_start);
238 /* the generic initrd code expects virtual addresses */
239 initrd_start = __phys_to_virt(initrd_start);
240 initrd_end = __phys_to_virt(initrd_end);
244 early_init_fdt_scan_reserved_mem();
246 /* 4GB maximum for 32-bit only capable devices */
247 if (IS_ENABLED(CONFIG_ZONE_DMA))
248 arm64_dma_phys_limit = max_zone_dma_phys();
250 arm64_dma_phys_limit = PHYS_MASK + 1;
251 dma_contiguous_reserve(arm64_dma_phys_limit);
253 memblock_allow_resize();
257 void __init bootmem_init(void)
259 unsigned long min, max;
261 min = PFN_UP(memblock_start_of_DRAM());
262 max = PFN_DOWN(memblock_end_of_DRAM());
264 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
267 * Sparsemem tries to allocate bootmem in memory_present(), so must be
268 * done after the fixed reservations.
270 arm64_memory_present();
273 zone_sizes_init(min, max);
275 high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
276 max_pfn = max_low_pfn = max;
279 #ifndef CONFIG_SPARSEMEM_VMEMMAP
280 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
282 struct page *start_pg, *end_pg;
283 unsigned long pg, pgend;
286 * Convert start_pfn/end_pfn to a struct page pointer.
288 start_pg = pfn_to_page(start_pfn - 1) + 1;
289 end_pg = pfn_to_page(end_pfn - 1) + 1;
292 * Convert to physical addresses, and round start upwards and end
295 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
296 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
299 * If there are free pages between these, free the section of the
303 free_bootmem(pg, pgend - pg);
307 * The mem_map array can get very big. Free the unused area of the memory map.
309 static void __init free_unused_memmap(void)
311 unsigned long start, prev_end = 0;
312 struct memblock_region *reg;
314 for_each_memblock(memory, reg) {
315 start = __phys_to_pfn(reg->base);
317 #ifdef CONFIG_SPARSEMEM
319 * Take care not to free memmap entries that don't exist due
320 * to SPARSEMEM sections which aren't present.
322 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
325 * If we had a previous bank, and there is a space between the
326 * current bank and the previous, free it.
328 if (prev_end && prev_end < start)
329 free_memmap(prev_end, start);
332 * Align up here since the VM subsystem insists that the
333 * memmap entries are valid from the bank end aligned to
334 * MAX_ORDER_NR_PAGES.
336 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
340 #ifdef CONFIG_SPARSEMEM
341 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
342 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
345 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
348 * mem_init() marks the free areas in the mem_map and tells us how much memory
349 * is free. This is done after various parts of the system have claimed their
350 * memory after the kernel image.
352 void __init mem_init(void)
356 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
358 #ifndef CONFIG_SPARSEMEM_VMEMMAP
359 free_unused_memmap();
361 /* this will put all unused low memory onto the freelists */
364 mem_init_print_info(NULL);
366 #define MLK(b, t) b, t, ((t) - (b)) >> 10
367 #define MLM(b, t) b, t, ((t) - (b)) >> 20
368 #define MLG(b, t) b, t, ((t) - (b)) >> 30
369 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
371 pr_notice("Virtual kernel memory layout:\n"
373 " kasan : 0x%16lx - 0x%16lx (%6ld GB)\n"
375 " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
376 " vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
377 " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
378 " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
379 " .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n"
380 " .data : 0x%p" " - 0x%p" " (%6ld KB)\n"
381 #ifdef CONFIG_SPARSEMEM_VMEMMAP
382 " vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
383 " 0x%16lx - 0x%16lx (%6ld MB actual)\n"
385 " fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
386 " PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
387 " memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
389 MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
391 MLM(MODULES_VADDR, MODULES_END),
392 MLG(VMALLOC_START, VMALLOC_END),
393 MLK_ROUNDUP(__init_begin, __init_end),
394 MLK_ROUNDUP(_text, _etext),
395 MLK_ROUNDUP(__start_rodata, __init_begin),
396 MLK_ROUNDUP(_sdata, _edata),
397 #ifdef CONFIG_SPARSEMEM_VMEMMAP
399 VMEMMAP_START + VMEMMAP_SIZE),
400 MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()),
401 (unsigned long)virt_to_page(high_memory)),
403 MLK(FIXADDR_START, FIXADDR_TOP),
404 MLM(PCI_IO_START, PCI_IO_END),
405 MLM(__phys_to_virt(memblock_start_of_DRAM()),
406 (unsigned long)high_memory));
413 * Check boundaries twice: Some fundamental inconsistencies can be
414 * detected at build time already.
417 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
419 BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
420 BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
422 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
423 extern int sysctl_overcommit_memory;
425 * On a machine this small we won't get anywhere without
426 * overcommit, so turn it on by default.
428 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
432 void free_initmem(void)
434 free_initmem_default(0);
438 #ifdef CONFIG_BLK_DEV_INITRD
440 static int keep_initrd __initdata;
442 void __init free_initrd_mem(unsigned long start, unsigned long end)
445 free_reserved_area((void *)start, (void *)end, 0, "initrd");
448 static int __init keepinitrd_setup(char *__unused)
454 __setup("keepinitrd", keepinitrd_setup);
458 * Dump out memory limit information on panic.
460 static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
462 if (memory_limit != (phys_addr_t)ULLONG_MAX) {
463 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
465 pr_emerg("Memory Limit: none\n");
470 static struct notifier_block mem_limit_notifier = {
471 .notifier_call = dump_mem_limit,
474 static int __init register_mem_limit_dumper(void)
476 atomic_notifier_chain_register(&panic_notifier_list,
477 &mem_limit_notifier);
480 __initcall(register_mem_limit_dumper);