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/memory.h>
40 #include <asm/sections.h>
41 #include <asm/setup.h>
42 #include <asm/sizes.h>
44 #include <asm/alternative.h>
48 phys_addr_t memstart_addr __read_mostly = 0;
49 phys_addr_t arm64_dma_phys_limit __read_mostly;
51 #ifdef CONFIG_BLK_DEV_INITRD
52 static int __init early_initrd(char *p)
54 unsigned long start, size;
57 start = memparse(p, &endp);
59 size = memparse(endp + 1, NULL);
61 initrd_start = (unsigned long)__va(start);
62 initrd_end = (unsigned long)__va(start + size);
66 early_param("initrd", early_initrd);
70 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
71 * currently assumes that for memory starting above 4G, 32-bit devices will
74 static phys_addr_t max_zone_dma_phys(void)
76 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
77 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
80 static void __init zone_sizes_init(unsigned long min, unsigned long max)
82 struct memblock_region *reg;
83 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
84 unsigned long max_dma = min;
86 memset(zone_size, 0, sizeof(zone_size));
88 /* 4GB maximum for 32-bit only capable devices */
89 #ifdef CONFIG_ZONE_DMA
90 max_dma = PFN_DOWN(arm64_dma_phys_limit);
91 zone_size[ZONE_DMA] = max_dma - min;
93 zone_size[ZONE_NORMAL] = max - max_dma;
95 memcpy(zhole_size, zone_size, sizeof(zhole_size));
97 for_each_memblock(memory, reg) {
98 unsigned long start = memblock_region_memory_base_pfn(reg);
99 unsigned long end = memblock_region_memory_end_pfn(reg);
104 #ifdef CONFIG_ZONE_DMA
105 if (start < max_dma) {
106 unsigned long dma_end = min(end, max_dma);
107 zhole_size[ZONE_DMA] -= dma_end - start;
111 unsigned long normal_end = min(end, max);
112 unsigned long normal_start = max(start, max_dma);
113 zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
117 free_area_init_node(0, zone_size, min, zhole_size);
120 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
121 int pfn_valid(unsigned long pfn)
123 phys_addr_t addr = pfn << PAGE_SHIFT;
125 if ((addr >> PAGE_SHIFT) != pfn)
127 return memblock_is_memory(addr);
129 EXPORT_SYMBOL(pfn_valid);
132 #ifndef CONFIG_SPARSEMEM
133 static void arm64_memory_present(void)
137 static void arm64_memory_present(void)
139 struct memblock_region *reg;
141 for_each_memblock(memory, reg)
142 memory_present(0, memblock_region_memory_base_pfn(reg),
143 memblock_region_memory_end_pfn(reg));
147 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
150 * Limit the memory size that was specified via FDT.
152 static int __init early_mem(char *p)
157 memory_limit = memparse(p, &p) & PAGE_MASK;
158 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
162 early_param("mem", early_mem);
164 void __init arm64_memblock_init(void)
166 memblock_enforce_memory_limit(memory_limit);
169 * Register the kernel text, kernel data, initrd, and initial
170 * pagetables with memblock.
172 memblock_reserve(__pa(_text), _end - _text);
173 #ifdef CONFIG_BLK_DEV_INITRD
175 memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
178 early_init_fdt_scan_reserved_mem();
180 /* 4GB maximum for 32-bit only capable devices */
181 if (IS_ENABLED(CONFIG_ZONE_DMA))
182 arm64_dma_phys_limit = max_zone_dma_phys();
184 arm64_dma_phys_limit = PHYS_MASK + 1;
185 high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
186 dma_contiguous_reserve(arm64_dma_phys_limit);
188 memblock_allow_resize();
192 void __init bootmem_init(void)
194 unsigned long min, max;
196 min = PFN_UP(memblock_start_of_DRAM());
197 max = PFN_DOWN(memblock_end_of_DRAM());
199 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
202 * Sparsemem tries to allocate bootmem in memory_present(), so must be
203 * done after the fixed reservations.
205 arm64_memory_present();
208 zone_sizes_init(min, max);
210 max_pfn = max_low_pfn = max;
213 #ifndef CONFIG_SPARSEMEM_VMEMMAP
214 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
216 struct page *start_pg, *end_pg;
217 unsigned long pg, pgend;
220 * Convert start_pfn/end_pfn to a struct page pointer.
222 start_pg = pfn_to_page(start_pfn - 1) + 1;
223 end_pg = pfn_to_page(end_pfn - 1) + 1;
226 * Convert to physical addresses, and round start upwards and end
229 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
230 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
233 * If there are free pages between these, free the section of the
237 free_bootmem(pg, pgend - pg);
241 * The mem_map array can get very big. Free the unused area of the memory map.
243 static void __init free_unused_memmap(void)
245 unsigned long start, prev_end = 0;
246 struct memblock_region *reg;
248 for_each_memblock(memory, reg) {
249 start = __phys_to_pfn(reg->base);
251 #ifdef CONFIG_SPARSEMEM
253 * Take care not to free memmap entries that don't exist due
254 * to SPARSEMEM sections which aren't present.
256 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
259 * If we had a previous bank, and there is a space between the
260 * current bank and the previous, free it.
262 if (prev_end && prev_end < start)
263 free_memmap(prev_end, start);
266 * Align up here since the VM subsystem insists that the
267 * memmap entries are valid from the bank end aligned to
268 * MAX_ORDER_NR_PAGES.
270 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
274 #ifdef CONFIG_SPARSEMEM
275 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
276 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
279 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
282 * mem_init() marks the free areas in the mem_map and tells us how much memory
283 * is free. This is done after various parts of the system have claimed their
284 * memory after the kernel image.
286 void __init mem_init(void)
290 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
292 #ifndef CONFIG_SPARSEMEM_VMEMMAP
293 free_unused_memmap();
295 /* this will put all unused low memory onto the freelists */
298 mem_init_print_info(NULL);
300 #define MLK(b, t) b, t, ((t) - (b)) >> 10
301 #define MLM(b, t) b, t, ((t) - (b)) >> 20
302 #define MLG(b, t) b, t, ((t) - (b)) >> 30
303 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
305 pr_notice("Virtual kernel memory layout:\n"
307 " kasan : 0x%16lx - 0x%16lx (%6ld GB)\n"
309 " vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
310 #ifdef CONFIG_SPARSEMEM_VMEMMAP
311 " vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
312 " 0x%16lx - 0x%16lx (%6ld MB actual)\n"
314 " fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
315 " PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
316 " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
317 " memory : 0x%16lx - 0x%16lx (%6ld MB)\n"
318 " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
319 " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
320 " .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
322 MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
324 MLG(VMALLOC_START, VMALLOC_END),
325 #ifdef CONFIG_SPARSEMEM_VMEMMAP
327 VMEMMAP_START + VMEMMAP_SIZE),
328 MLM((unsigned long)virt_to_page(PAGE_OFFSET),
329 (unsigned long)virt_to_page(high_memory)),
331 MLK(FIXADDR_START, FIXADDR_TOP),
332 MLM(PCI_IO_START, PCI_IO_END),
333 MLM(MODULES_VADDR, MODULES_END),
334 MLM(PAGE_OFFSET, (unsigned long)high_memory),
335 MLK_ROUNDUP(__init_begin, __init_end),
336 MLK_ROUNDUP(_text, _etext),
337 MLK_ROUNDUP(_sdata, _edata));
344 * Check boundaries twice: Some fundamental inconsistencies can be
345 * detected at build time already.
348 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
350 BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
351 BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
353 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
354 extern int sysctl_overcommit_memory;
356 * On a machine this small we won't get anywhere without
357 * overcommit, so turn it on by default.
359 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
363 void free_initmem(void)
366 free_initmem_default(0);
367 free_alternatives_memory();
370 #ifdef CONFIG_BLK_DEV_INITRD
372 static int keep_initrd __initdata;
374 void __init free_initrd_mem(unsigned long start, unsigned long end)
377 free_reserved_area((void *)start, (void *)end, 0, "initrd");
380 static int __init keepinitrd_setup(char *__unused)
386 __setup("keepinitrd", keepinitrd_setup);