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>
36 #include <asm/sections.h>
37 #include <asm/setup.h>
38 #include <asm/sizes.h>
43 phys_addr_t memstart_addr __read_mostly = 0;
45 #ifdef CONFIG_BLK_DEV_INITRD
46 static int __init early_initrd(char *p)
48 unsigned long start, size;
51 start = memparse(p, &endp);
53 size = memparse(endp + 1, NULL);
55 initrd_start = (unsigned long)__va(start);
56 initrd_end = (unsigned long)__va(start + size);
60 early_param("initrd", early_initrd);
64 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
65 * currently assumes that for memory starting above 4G, 32-bit devices will
68 static phys_addr_t max_zone_dma_phys(void)
70 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
71 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
74 static void __init zone_sizes_init(unsigned long min, unsigned long max)
76 struct memblock_region *reg;
77 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
78 unsigned long max_dma = min;
80 memset(zone_size, 0, sizeof(zone_size));
82 /* 4GB maximum for 32-bit only capable devices */
83 if (IS_ENABLED(CONFIG_ZONE_DMA)) {
84 max_dma = PFN_DOWN(max_zone_dma_phys());
85 zone_size[ZONE_DMA] = max_dma - min;
87 zone_size[ZONE_NORMAL] = max - max_dma;
89 memcpy(zhole_size, zone_size, sizeof(zhole_size));
91 for_each_memblock(memory, reg) {
92 unsigned long start = memblock_region_memory_base_pfn(reg);
93 unsigned long end = memblock_region_memory_end_pfn(reg);
98 if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
99 unsigned long dma_end = min(end, max_dma);
100 zhole_size[ZONE_DMA] -= dma_end - start;
104 unsigned long normal_end = min(end, max);
105 unsigned long normal_start = max(start, max_dma);
106 zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
110 free_area_init_node(0, zone_size, min, zhole_size);
113 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
114 int pfn_valid(unsigned long pfn)
116 return memblock_is_memory(pfn << PAGE_SHIFT);
118 EXPORT_SYMBOL(pfn_valid);
121 #ifndef CONFIG_SPARSEMEM
122 static void arm64_memory_present(void)
126 static void arm64_memory_present(void)
128 struct memblock_region *reg;
130 for_each_memblock(memory, reg)
131 memory_present(0, memblock_region_memory_base_pfn(reg),
132 memblock_region_memory_end_pfn(reg));
136 void __init arm64_memblock_init(void)
138 phys_addr_t dma_phys_limit = 0;
140 /* Register the kernel text, kernel data and initrd with memblock */
141 memblock_reserve(__pa(_text), _end - _text);
142 #ifdef CONFIG_BLK_DEV_INITRD
144 memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
148 * Reserve the page tables. These are already in use,
149 * and can only be in node 0.
151 memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
152 memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
154 early_init_fdt_scan_reserved_mem();
156 /* 4GB maximum for 32-bit only capable devices */
157 if (IS_ENABLED(CONFIG_ZONE_DMA))
158 dma_phys_limit = max_zone_dma_phys();
159 dma_contiguous_reserve(dma_phys_limit);
161 memblock_allow_resize();
165 void __init bootmem_init(void)
167 unsigned long min, max;
169 min = PFN_UP(memblock_start_of_DRAM());
170 max = PFN_DOWN(memblock_end_of_DRAM());
173 * Sparsemem tries to allocate bootmem in memory_present(), so must be
174 * done after the fixed reservations.
176 arm64_memory_present();
179 zone_sizes_init(min, max);
181 high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
182 max_pfn = max_low_pfn = max;
185 #ifndef CONFIG_SPARSEMEM_VMEMMAP
186 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
188 struct page *start_pg, *end_pg;
189 unsigned long pg, pgend;
192 * Convert start_pfn/end_pfn to a struct page pointer.
194 start_pg = pfn_to_page(start_pfn - 1) + 1;
195 end_pg = pfn_to_page(end_pfn - 1) + 1;
198 * Convert to physical addresses, and round start upwards and end
201 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
202 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
205 * If there are free pages between these, free the section of the
209 free_bootmem(pg, pgend - pg);
213 * The mem_map array can get very big. Free the unused area of the memory map.
215 static void __init free_unused_memmap(void)
217 unsigned long start, prev_end = 0;
218 struct memblock_region *reg;
220 for_each_memblock(memory, reg) {
221 start = __phys_to_pfn(reg->base);
223 #ifdef CONFIG_SPARSEMEM
225 * Take care not to free memmap entries that don't exist due
226 * to SPARSEMEM sections which aren't present.
228 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
231 * If we had a previous bank, and there is a space between the
232 * current bank and the previous, free it.
234 if (prev_end && prev_end < start)
235 free_memmap(prev_end, start);
238 * Align up here since the VM subsystem insists that the
239 * memmap entries are valid from the bank end aligned to
240 * MAX_ORDER_NR_PAGES.
242 prev_end = ALIGN(start + __phys_to_pfn(reg->size),
246 #ifdef CONFIG_SPARSEMEM
247 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
248 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
251 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
254 * mem_init() marks the free areas in the mem_map and tells us how much memory
255 * is free. This is done after various parts of the system have claimed their
256 * memory after the kernel image.
258 void __init mem_init(void)
260 max_mapnr = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
262 #ifndef CONFIG_SPARSEMEM_VMEMMAP
263 free_unused_memmap();
265 /* this will put all unused low memory onto the freelists */
268 mem_init_print_info(NULL);
270 #define MLK(b, t) b, t, ((t) - (b)) >> 10
271 #define MLM(b, t) b, t, ((t) - (b)) >> 20
272 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
274 pr_notice("Virtual kernel memory layout:\n"
275 " vmalloc : 0x%16lx - 0x%16lx (%6ld MB)\n"
276 #ifdef CONFIG_SPARSEMEM_VMEMMAP
277 " vmemmap : 0x%16lx - 0x%16lx (%6ld MB)\n"
279 " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
280 " memory : 0x%16lx - 0x%16lx (%6ld MB)\n"
281 " .init : 0x%p" " - 0x%p" " (%6ld kB)\n"
282 " .text : 0x%p" " - 0x%p" " (%6ld kB)\n"
283 " .data : 0x%p" " - 0x%p" " (%6ld kB)\n",
284 MLM(VMALLOC_START, VMALLOC_END),
285 #ifdef CONFIG_SPARSEMEM_VMEMMAP
286 MLM((unsigned long)virt_to_page(PAGE_OFFSET),
287 (unsigned long)virt_to_page(high_memory)),
289 MLM(MODULES_VADDR, MODULES_END),
290 MLM(PAGE_OFFSET, (unsigned long)high_memory),
292 MLK_ROUNDUP(__init_begin, __init_end),
293 MLK_ROUNDUP(_text, _etext),
294 MLK_ROUNDUP(_sdata, _edata));
301 * Check boundaries twice: Some fundamental inconsistencies can be
302 * detected at build time already.
305 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
307 BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
308 BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
310 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
311 extern int sysctl_overcommit_memory;
313 * On a machine this small we won't get anywhere without
314 * overcommit, so turn it on by default.
316 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
320 void free_initmem(void)
322 free_initmem_default(0);
325 #ifdef CONFIG_BLK_DEV_INITRD
327 static int keep_initrd;
329 void free_initrd_mem(unsigned long start, unsigned long end)
332 free_reserved_area((void *)start, (void *)end, 0, "initrd");
335 static int __init keepinitrd_setup(char *__unused)
341 __setup("keepinitrd", keepinitrd_setup);