linux/arch/arm64/mm/init.c
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   1/*
   2 * Based on arch/arm/mm/init.c
   3 *
   4 * Copyright (C) 1995-2005 Russell King
   5 * Copyright (C) 2012 ARM Ltd.
   6 *
   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.
  10 *
  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.
  15 *
  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/>.
  18 */
  19
  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
  34#include <asm/prom.h>
  35#include <asm/sections.h>
  36#include <asm/setup.h>
  37#include <asm/sizes.h>
  38#include <asm/tlb.h>
  39
  40#include "mm.h"
  41
  42static unsigned long phys_initrd_start __initdata = 0;
  43static unsigned long phys_initrd_size __initdata = 0;
  44
  45phys_addr_t memstart_addr __read_mostly = 0;
  46
  47void __init early_init_dt_setup_initrd_arch(unsigned long start,
  48                                            unsigned long end)
  49{
  50        phys_initrd_start = start;
  51        phys_initrd_size = end - start;
  52}
  53
  54static int __init early_initrd(char *p)
  55{
  56        unsigned long start, size;
  57        char *endp;
  58
  59        start = memparse(p, &endp);
  60        if (*endp == ',') {
  61                size = memparse(endp + 1, NULL);
  62
  63                phys_initrd_start = start;
  64                phys_initrd_size = size;
  65        }
  66        return 0;
  67}
  68early_param("initrd", early_initrd);
  69
  70#define MAX_DMA32_PFN ((4UL * 1024 * 1024 * 1024) >> PAGE_SHIFT)
  71
  72static void __init zone_sizes_init(unsigned long min, unsigned long max)
  73{
  74        struct memblock_region *reg;
  75        unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
  76        unsigned long max_dma32 = min;
  77
  78        memset(zone_size, 0, sizeof(zone_size));
  79
  80#ifdef CONFIG_ZONE_DMA32
  81        /* 4GB maximum for 32-bit only capable devices */
  82        max_dma32 = max(min, min(max, MAX_DMA32_PFN));
  83        zone_size[ZONE_DMA32] = max_dma32 - min;
  84#endif
  85        zone_size[ZONE_NORMAL] = max - max_dma32;
  86
  87        memcpy(zhole_size, zone_size, sizeof(zhole_size));
  88
  89        for_each_memblock(memory, reg) {
  90                unsigned long start = memblock_region_memory_base_pfn(reg);
  91                unsigned long end = memblock_region_memory_end_pfn(reg);
  92
  93                if (start >= max)
  94                        continue;
  95#ifdef CONFIG_ZONE_DMA32
  96                if (start < max_dma32) {
  97                        unsigned long dma_end = min(end, max_dma32);
  98                        zhole_size[ZONE_DMA32] -= dma_end - start;
  99                }
 100#endif
 101                if (end > max_dma32) {
 102                        unsigned long normal_end = min(end, max);
 103                        unsigned long normal_start = max(start, max_dma32);
 104                        zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
 105                }
 106        }
 107
 108        free_area_init_node(0, zone_size, min, zhole_size);
 109}
 110
 111#ifdef CONFIG_HAVE_ARCH_PFN_VALID
 112int pfn_valid(unsigned long pfn)
 113{
 114        return memblock_is_memory(pfn << PAGE_SHIFT);
 115}
 116EXPORT_SYMBOL(pfn_valid);
 117#endif
 118
 119#ifndef CONFIG_SPARSEMEM
 120static void arm64_memory_present(void)
 121{
 122}
 123#else
 124static void arm64_memory_present(void)
 125{
 126        struct memblock_region *reg;
 127
 128        for_each_memblock(memory, reg)
 129                memory_present(0, memblock_region_memory_base_pfn(reg),
 130                               memblock_region_memory_end_pfn(reg));
 131}
 132#endif
 133
 134void __init arm64_memblock_init(void)
 135{
 136        u64 *reserve_map, base, size;
 137
 138        /* Register the kernel text, kernel data and initrd with memblock */
 139        memblock_reserve(__pa(_text), _end - _text);
 140#ifdef CONFIG_BLK_DEV_INITRD
 141        if (phys_initrd_size) {
 142                memblock_reserve(phys_initrd_start, phys_initrd_size);
 143
 144                /* Now convert initrd to virtual addresses */
 145                initrd_start = __phys_to_virt(phys_initrd_start);
 146                initrd_end = initrd_start + phys_initrd_size;
 147        }
 148#endif
 149
 150        /*
 151         * Reserve the page tables.  These are already in use,
 152         * and can only be in node 0.
 153         */
 154        memblock_reserve(__pa(swapper_pg_dir), SWAPPER_DIR_SIZE);
 155        memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE);
 156
 157        /* Reserve the dtb region */
 158        memblock_reserve(virt_to_phys(initial_boot_params),
 159                         be32_to_cpu(initial_boot_params->totalsize));
 160
 161        /*
 162         * Process the reserve map.  This will probably overlap the initrd
 163         * and dtb locations which are already reserved, but overlapping
 164         * doesn't hurt anything
 165         */
 166        reserve_map = ((void*)initial_boot_params) +
 167                        be32_to_cpu(initial_boot_params->off_mem_rsvmap);
 168        while (1) {
 169                base = be64_to_cpup(reserve_map++);
 170                size = be64_to_cpup(reserve_map++);
 171                if (!size)
 172                        break;
 173                memblock_reserve(base, size);
 174        }
 175
 176        memblock_allow_resize();
 177        memblock_dump_all();
 178}
 179
 180void __init bootmem_init(void)
 181{
 182        unsigned long min, max;
 183
 184        min = PFN_UP(memblock_start_of_DRAM());
 185        max = PFN_DOWN(memblock_end_of_DRAM());
 186
 187        /*
 188         * Sparsemem tries to allocate bootmem in memory_present(), so must be
 189         * done after the fixed reservations.
 190         */
 191        arm64_memory_present();
 192
 193        sparse_init();
 194        zone_sizes_init(min, max);
 195
 196        high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
 197        max_pfn = max_low_pfn = max;
 198}
 199
 200#ifndef CONFIG_SPARSEMEM_VMEMMAP
 201static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 202{
 203        struct page *start_pg, *end_pg;
 204        unsigned long pg, pgend;
 205
 206        /*
 207         * Convert start_pfn/end_pfn to a struct page pointer.
 208         */
 209        start_pg = pfn_to_page(start_pfn - 1) + 1;
 210        end_pg = pfn_to_page(end_pfn - 1) + 1;
 211
 212        /*
 213         * Convert to physical addresses, and round start upwards and end
 214         * downwards.
 215         */
 216        pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
 217        pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
 218
 219        /*
 220         * If there are free pages between these, free the section of the
 221         * memmap array.
 222         */
 223        if (pg < pgend)
 224                free_bootmem(pg, pgend - pg);
 225}
 226
 227/*
 228 * The mem_map array can get very big. Free the unused area of the memory map.
 229 */
 230static void __init free_unused_memmap(void)
 231{
 232        unsigned long start, prev_end = 0;
 233        struct memblock_region *reg;
 234
 235        for_each_memblock(memory, reg) {
 236                start = __phys_to_pfn(reg->base);
 237
 238#ifdef CONFIG_SPARSEMEM
 239                /*
 240                 * Take care not to free memmap entries that don't exist due
 241                 * to SPARSEMEM sections which aren't present.
 242                 */
 243                start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
 244#endif
 245                /*
 246                 * If we had a previous bank, and there is a space between the
 247                 * current bank and the previous, free it.
 248                 */
 249                if (prev_end && prev_end < start)
 250                        free_memmap(prev_end, start);
 251
 252                /*
 253                 * Align up here since the VM subsystem insists that the
 254                 * memmap entries are valid from the bank end aligned to
 255                 * MAX_ORDER_NR_PAGES.
 256                 */
 257                prev_end = ALIGN(start + __phys_to_pfn(reg->size),
 258                                 MAX_ORDER_NR_PAGES);
 259        }
 260
 261#ifdef CONFIG_SPARSEMEM
 262        if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 263                free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
 264#endif
 265}
 266#endif  /* !CONFIG_SPARSEMEM_VMEMMAP */
 267
 268/*
 269 * mem_init() marks the free areas in the mem_map and tells us how much memory
 270 * is free.  This is done after various parts of the system have claimed their
 271 * memory after the kernel image.
 272 */
 273void __init mem_init(void)
 274{
 275        arm64_swiotlb_init();
 276
 277        max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;
 278
 279#ifndef CONFIG_SPARSEMEM_VMEMMAP
 280        free_unused_memmap();
 281#endif
 282        /* this will put all unused low memory onto the freelists */
 283        free_all_bootmem();
 284
 285        mem_init_print_info(NULL);
 286
 287#define MLK(b, t) b, t, ((t) - (b)) >> 10
 288#define MLM(b, t) b, t, ((t) - (b)) >> 20
 289#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 290
 291        pr_notice("Virtual kernel memory layout:\n"
 292                  "    vmalloc : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 293#ifdef CONFIG_SPARSEMEM_VMEMMAP
 294                  "    vmemmap : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 295#endif
 296                  "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 297                  "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 298                  "      .init : 0x%p" " - 0x%p" "   (%6ld kB)\n"
 299                  "      .text : 0x%p" " - 0x%p" "   (%6ld kB)\n"
 300                  "      .data : 0x%p" " - 0x%p" "   (%6ld kB)\n",
 301                  MLM(VMALLOC_START, VMALLOC_END),
 302#ifdef CONFIG_SPARSEMEM_VMEMMAP
 303                  MLM((unsigned long)virt_to_page(PAGE_OFFSET),
 304                      (unsigned long)virt_to_page(high_memory)),
 305#endif
 306                  MLM(MODULES_VADDR, MODULES_END),
 307                  MLM(PAGE_OFFSET, (unsigned long)high_memory),
 308
 309                  MLK_ROUNDUP(__init_begin, __init_end),
 310                  MLK_ROUNDUP(_text, _etext),
 311                  MLK_ROUNDUP(_sdata, _edata));
 312
 313#undef MLK
 314#undef MLM
 315#undef MLK_ROUNDUP
 316
 317        /*
 318         * Check boundaries twice: Some fundamental inconsistencies can be
 319         * detected at build time already.
 320         */
 321#ifdef CONFIG_COMPAT
 322        BUILD_BUG_ON(TASK_SIZE_32                       > TASK_SIZE_64);
 323#endif
 324        BUILD_BUG_ON(TASK_SIZE_64                       > MODULES_VADDR);
 325        BUG_ON(TASK_SIZE_64                             > MODULES_VADDR);
 326
 327        if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 328                extern int sysctl_overcommit_memory;
 329                /*
 330                 * On a machine this small we won't get anywhere without
 331                 * overcommit, so turn it on by default.
 332                 */
 333                sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 334        }
 335}
 336
 337void free_initmem(void)
 338{
 339        free_initmem_default(0);
 340}
 341
 342#ifdef CONFIG_BLK_DEV_INITRD
 343
 344static int keep_initrd;
 345
 346void free_initrd_mem(unsigned long start, unsigned long end)
 347{
 348        if (!keep_initrd)
 349                free_reserved_area((void *)start, (void *)end, 0, "initrd");
 350}
 351
 352static int __init keepinitrd_setup(char *__unused)
 353{
 354        keep_initrd = 1;
 355        return 1;
 356}
 357
 358__setup("keepinitrd", keepinitrd_setup);
 359#endif
 360