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>
38 #include <asm/fixmap.h>
39 #include <asm/kasan.h>
40 #include <asm/memory.h>
41 #include <asm/sections.h>
42 #include <asm/setup.h>
43 #include <asm/sizes.h>
45 #include <asm/alternative.h>
49 phys_addr_t memstart_addr __read_mostly = 0;
50 phys_addr_t arm64_dma_phys_limit __read_mostly;
52 #ifdef CONFIG_BLK_DEV_INITRD
53 static int __init early_initrd(char *p)
55 unsigned long start, size;
58 start = memparse(p, &endp);
60 size = memparse(endp + 1, NULL);
63 initrd_end = start + size;
67 early_param("initrd", early_initrd);
71 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
72 * currently assumes that for memory starting above 4G, 32-bit devices will
75 static phys_addr_t __init max_zone_dma_phys(void)
77 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
78 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
81 static void __init zone_sizes_init(unsigned long min, unsigned long max)
83 struct memblock_region *reg;
84 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
85 unsigned long max_dma = min;
87 memset(zone_size, 0, sizeof(zone_size));
89 /* 4GB maximum for 32-bit only capable devices */
90 #ifdef CONFIG_ZONE_DMA
91 max_dma = PFN_DOWN(arm64_dma_phys_limit);
92 zone_size[ZONE_DMA] = max_dma - min;
94 zone_size[ZONE_NORMAL] = max - max_dma;
96 memcpy(zhole_size, zone_size, sizeof(zhole_size));
98 for_each_memblock(memory, reg) {
99 unsigned long start = memblock_region_memory_base_pfn(reg);
100 unsigned long end = memblock_region_memory_end_pfn(reg);
105 #ifdef CONFIG_ZONE_DMA
106 if (start < max_dma) {
107 unsigned long dma_end = min(end, max_dma);
108 zhole_size[ZONE_DMA] -= dma_end - start;
112 unsigned long normal_end = min(end, max);
113 unsigned long normal_start = max(start, max_dma);
114 zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
118 free_area_init_node(0, zone_size, min, zhole_size);
121 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
122 int pfn_valid(unsigned long pfn)
124 return memblock_is_memory(pfn << PAGE_SHIFT);
126 EXPORT_SYMBOL(pfn_valid);
129 #ifndef CONFIG_SPARSEMEM
130 static void __init arm64_memory_present(void)
134 static void __init arm64_memory_present(void)
136 struct memblock_region *reg;
138 for_each_memblock(memory, reg)
139 memory_present(0, memblock_region_memory_base_pfn(reg),
140 memblock_region_memory_end_pfn(reg));
144 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
147 * Limit the memory size that was specified via FDT.
149 static int __init early_mem(char *p)
154 memory_limit = memparse(p, &p) & PAGE_MASK;
155 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
159 early_param("mem", early_mem);
161 void __init arm64_memblock_init(void)
163 memblock_enforce_memory_limit(memory_limit);
166 * Register the kernel text, kernel data, initrd, and initial
167 * pagetables with memblock.
169 memblock_reserve(__pa(_text), _end - _text);
170 #ifdef CONFIG_BLK_DEV_INITRD
172 memblock_reserve(initrd_start, initrd_end - initrd_start);
174 /* the generic initrd code expects virtual addresses */
175 initrd_start = __phys_to_virt(initrd_start);
176 initrd_end = __phys_to_virt(initrd_end);
180 early_init_fdt_scan_reserved_mem();
182 /* 4GB maximum for 32-bit only capable devices */
183 if (IS_ENABLED(CONFIG_ZONE_DMA))
184 arm64_dma_phys_limit = max_zone_dma_phys();
186 arm64_dma_phys_limit = PHYS_MASK + 1;
187 dma_contiguous_reserve(arm64_dma_phys_limit);
189 memblock_allow_resize();
193 void __init bootmem_init(void)
195 unsigned long min, max;
197 min = PFN_UP(memblock_start_of_DRAM());
198 max = PFN_DOWN(memblock_end_of_DRAM());
200 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
203 * Sparsemem tries to allocate bootmem in memory_present(), so must be
204 * done after the fixed reservations.
206 arm64_memory_present();
209 zone_sizes_init(min, max);
211 high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
212 max_pfn = max_low_pfn = max;
215 #ifndef CONFIG_SPARSEMEM_VMEMMAP
216 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
218 struct page *start_pg, *end_pg;
219 unsigned long pg, pgend;
222 * Convert start_pfn/end_pfn to a struct page pointer.
224 start_pg = pfn_to_page(start_pfn - 1) + 1;
225 end_pg = pfn_to_page(end_pfn - 1) + 1;
228 * Convert to physical addresses, and round start upwards and end
231 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
232 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
235 * If there are free pages between these, free the section of the
239 free_bootmem(pg, pgend - pg);
243 * The mem_map array can get very big. Free the unused area of the memory map.
245 static void __init free_unused_memmap(void)
247 unsigned long start, prev_end = 0;
248 struct memblock_region *reg;
250 for_each_memblock(memory, reg) {
251 start = __phys_to_pfn(reg->base);
253 #ifdef CONFIG_SPARSEMEM
255 * Take care not to free memmap entries that don't exist due
256 * to SPARSEMEM sections which aren't present.
258 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
261 * If we had a previous bank, and there is a space between the
262 * current bank and the previous, free it.
264 if (prev_end && prev_end < start)
265 free_memmap(prev_end, start);
268 * Align up here since the VM subsystem insists that the
269 * memmap entries are valid from the bank end aligned to
270 * MAX_ORDER_NR_PAGES.
272 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
276 #ifdef CONFIG_SPARSEMEM
277 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
278 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
281 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
284 * mem_init() marks the free areas in the mem_map and tells us how much memory
285 * is free. This is done after various parts of the system have claimed their
286 * memory after the kernel image.
288 void __init mem_init(void)
292 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
294 #ifndef CONFIG_SPARSEMEM_VMEMMAP
295 free_unused_memmap();
297 /* this will put all unused low memory onto the freelists */
300 mem_init_print_info(NULL);
302 #define MLK(b, t) b, t, ((t) - (b)) >> 10
303 #define MLM(b, t) b, t, ((t) - (b)) >> 20
304 #define MLG(b, t) b, t, ((t) - (b)) >> 30
305 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
307 pr_notice("Virtual kernel memory layout:\n"
309 " kasan : 0x%16lx - 0x%16lx (%6ld GB)\n"
311 " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
312 " vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
313 " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
314 " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
315 " .data : 0x%p" " - 0x%p" " (%6ld KB)\n"
316 #ifdef CONFIG_SPARSEMEM_VMEMMAP
317 " vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
318 " 0x%16lx - 0x%16lx (%6ld MB actual)\n"
320 " fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
321 " PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
322 " memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
324 MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
326 MLM(MODULES_VADDR, MODULES_END),
327 MLG(VMALLOC_START, VMALLOC_END),
328 MLK_ROUNDUP(__init_begin, __init_end),
329 MLK_ROUNDUP(_text, _etext),
330 MLK_ROUNDUP(_sdata, _edata),
331 #ifdef CONFIG_SPARSEMEM_VMEMMAP
333 VMEMMAP_START + VMEMMAP_SIZE),
334 MLM((unsigned long)virt_to_page(PAGE_OFFSET),
335 (unsigned long)virt_to_page(high_memory)),
337 MLK(FIXADDR_START, FIXADDR_TOP),
338 MLM(PCI_IO_START, PCI_IO_END),
339 MLM(PAGE_OFFSET, (unsigned long)high_memory));
346 * Check boundaries twice: Some fundamental inconsistencies can be
347 * detected at build time already.
350 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
352 BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
353 BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
355 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
356 extern int sysctl_overcommit_memory;
358 * On a machine this small we won't get anywhere without
359 * overcommit, so turn it on by default.
361 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
365 void free_initmem(void)
367 free_initmem_default(0);
371 #ifdef CONFIG_BLK_DEV_INITRD
373 static int keep_initrd __initdata;
375 void __init free_initrd_mem(unsigned long start, unsigned long end)
378 free_reserved_area((void *)start, (void *)end, 0, "initrd");
381 static int __init keepinitrd_setup(char *__unused)
387 __setup("keepinitrd", keepinitrd_setup);