arch/arm64/mm/init.c

   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 #include <linux/dma-mapping.h>
  34 #include <linux/dma-contiguous.h>
  35 #include <linux/efi.h>
  36
  37 #include <asm/fixmap.h>
  38 #include <asm/sections.h>
  39 #include <asm/setup.h>
  40 #include <asm/sizes.h>
  41 #include <asm/tlb.h>
  42 #include <asm/alternative.h>
  43
  44 #include "mm.h"
  45
  46 phys_addr_t memstart_addr __read_mostly = 0;
  47
  48 #ifdef CONFIG_BLK_DEV_INITRD
  49 static int __init early_initrd(char *p)
  50 {
  51         unsigned long start, size;
  52         char *endp;
  53
  54         start = memparse(p, &endp);
  55         if (*endp == ',') {
  56                 size = memparse(endp + 1, NULL);
  57
  58                 initrd_start = (unsigned long)__va(start);
  59                 initrd_end = (unsigned long)__va(start + size);
  60         }
  61         return 0;
  62 }
  63 early_param("initrd", early_initrd);
  64 #endif
  65
  66 /*
  67  * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
  68  * currently assumes that for memory starting above 4G, 32-bit devices will
  69  * use a DMA offset.
  70  */
  71 static phys_addr_t max_zone_dma_phys(void)
  72 {
  73         phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
  74         return min(offset + (1ULL << 32), memblock_end_of_DRAM());
  75 }
  76
  77 static void __init zone_sizes_init(unsigned long min, unsigned long max)
  78 {
  79         struct memblock_region *reg;
  80         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
  81         unsigned long max_dma = min;
  82
  83         memset(zone_size, 0, sizeof(zone_size));
  84
  85         /* 4GB maximum for 32-bit only capable devices */
  86         if (IS_ENABLED(CONFIG_ZONE_DMA)) {
  87                 max_dma = PFN_DOWN(max_zone_dma_phys());
  88                 zone_size[ZONE_DMA] = max_dma - min;
  89         }
  90         zone_size[ZONE_NORMAL] = max - max_dma;
  91
  92         memcpy(zhole_size, zone_size, sizeof(zhole_size));
  93
  94         for_each_memblock(memory, reg) {
  95                 unsigned long start = memblock_region_memory_base_pfn(reg);
  96                 unsigned long end = memblock_region_memory_end_pfn(reg);
  97
  98                 if (start >= max)
  99                         continue;
 100
 101                 if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
 102                         unsigned long dma_end = min(end, max_dma);
 103                         zhole_size[ZONE_DMA] -= dma_end - start;
 104                 }
 105
 106                 if (end > max_dma) {
 107                         unsigned long normal_end = min(end, max);
 108                         unsigned long normal_start = max(start, max_dma);
 109                         zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
 110                 }
 111         }
 112
 113         free_area_init_node(0, zone_size, min, zhole_size);
 114 }
 115
 116 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 117 int pfn_valid(unsigned long pfn)
 118 {
 119         return memblock_is_memory(pfn << PAGE_SHIFT);
 120 }
 121 EXPORT_SYMBOL(pfn_valid);
 122 #endif
 123
 124 #ifndef CONFIG_SPARSEMEM
 125 static void arm64_memory_present(void)
 126 {
 127 }
 128 #else
 129 static void arm64_memory_present(void)
 130 {
 131         struct memblock_region *reg;
 132
 133         for_each_memblock(memory, reg)
 134                 memory_present(0, memblock_region_memory_base_pfn(reg),
 135                                memblock_region_memory_end_pfn(reg));
 136 }
 137 #endif
 138
 139 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
 140
 141 /*
 142  * Limit the memory size that was specified via FDT.
 143  */
 144 static int __init early_mem(char *p)
 145 {
 146         if (!p)
 147                 return 1;
 148
 149         memory_limit = memparse(p, &p) & PAGE_MASK;
 150         pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
 151
 152         return 0;
 153 }
 154 early_param("mem", early_mem);
 155
 156 void __init arm64_memblock_init(void)
 157 {
 158         phys_addr_t dma_phys_limit = 0;
 159
 160         memblock_enforce_memory_limit(memory_limit);
 161
 162         /*
 163          * Register the kernel text, kernel data, initrd, and initial
 164          * pagetables with memblock.
 165          */
 166         memblock_reserve(__pa(_text), _end - _text);
 167 #ifdef CONFIG_BLK_DEV_INITRD
 168         if (initrd_start)
 169                 memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
 170 #endif
 171
 172         early_init_fdt_scan_reserved_mem();
 173
 174         /* 4GB maximum for 32-bit only capable devices */
 175         if (IS_ENABLED(CONFIG_ZONE_DMA))
 176                 dma_phys_limit = max_zone_dma_phys();
 177         dma_contiguous_reserve(dma_phys_limit);
 178
 179         memblock_allow_resize();
 180         memblock_dump_all();
 181 }
 182
 183 void __init bootmem_init(void)
 184 {
 185         unsigned long min, max;
 186
 187         min = PFN_UP(memblock_start_of_DRAM());
 188         max = PFN_DOWN(memblock_end_of_DRAM());
 189
 190         /*
 191          * Sparsemem tries to allocate bootmem in memory_present(), so must be
 192          * done after the fixed reservations.
 193          */
 194         arm64_memory_present();
 195
 196         sparse_init();
 197         zone_sizes_init(min, max);
 198
 199         high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
 200         max_pfn = max_low_pfn = max;
 201 }
 202
 203 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 204 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 205 {
 206         struct page *start_pg, *end_pg;
 207         unsigned long pg, pgend;
 208
 209         /*
 210          * Convert start_pfn/end_pfn to a struct page pointer.
 211          */
 212         start_pg = pfn_to_page(start_pfn - 1) + 1;
 213         end_pg = pfn_to_page(end_pfn - 1) + 1;
 214
 215         /*
 216          * Convert to physical addresses, and round start upwards and end
 217          * downwards.
 218          */
 219         pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
 220         pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
 221
 222         /*
 223          * If there are free pages between these, free the section of the
 224          * memmap array.
 225          */
 226         if (pg < pgend)
 227                 free_bootmem(pg, pgend - pg);
 228 }
 229
 230 /*
 231  * The mem_map array can get very big. Free the unused area of the memory map.
 232  */
 233 static void __init free_unused_memmap(void)
 234 {
 235         unsigned long start, prev_end = 0;
 236         struct memblock_region *reg;
 237
 238         for_each_memblock(memory, reg) {
 239                 start = __phys_to_pfn(reg->base);
 240
 241 #ifdef CONFIG_SPARSEMEM
 242                 /*
 243                  * Take care not to free memmap entries that don't exist due
 244                  * to SPARSEMEM sections which aren't present.
 245                  */
 246                 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
 247 #endif
 248                 /*
 249                  * If we had a previous bank, and there is a space between the
 250                  * current bank and the previous, free it.
 251                  */
 252                 if (prev_end && prev_end < start)
 253                         free_memmap(prev_end, start);
 254
 255                 /*
 256                  * Align up here since the VM subsystem insists that the
 257                  * memmap entries are valid from the bank end aligned to
 258                  * MAX_ORDER_NR_PAGES.
 259                  */
 260                 prev_end = ALIGN(start + __phys_to_pfn(reg->size),
 261                                  MAX_ORDER_NR_PAGES);
 262         }
 263
 264 #ifdef CONFIG_SPARSEMEM
 265         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 266                 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
 267 #endif
 268 }
 269 #endif  /* !CONFIG_SPARSEMEM_VMEMMAP */
 270
 271 /*
 272  * mem_init() marks the free areas in the mem_map and tells us how much memory
 273  * is free.  This is done after various parts of the system have claimed their
 274  * memory after the kernel image.
 275  */
 276 void __init mem_init(void)
 277 {
 278         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 279
 280 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 281         free_unused_memmap();
 282 #endif
 283         /* this will put all unused low memory onto the freelists */
 284         free_all_bootmem();
 285
 286         mem_init_print_info(NULL);
 287
 288 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 289 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 290 #define MLG(b, t) b, t, ((t) - (b)) >> 30
 291 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 292
 293         pr_notice("Virtual kernel memory layout:\n"
 294                   "    vmalloc : 0x%16lx - 0x%16lx   (%6ld GB)\n"
 295 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 296                   "    vmemmap : 0x%16lx - 0x%16lx   (%6ld GB maximum)\n"
 297                   "              0x%16lx - 0x%16lx   (%6ld MB actual)\n"
 298 #endif
 299                   "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 300                   "    fixed   : 0x%16lx - 0x%16lx   (%6ld KB)\n"
 301                   "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 302                   "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 303                   "      .init : 0x%p" " - 0x%p" "   (%6ld KB)\n"
 304                   "      .text : 0x%p" " - 0x%p" "   (%6ld KB)\n"
 305                   "      .data : 0x%p" " - 0x%p" "   (%6ld KB)\n",
 306                   MLG(VMALLOC_START, VMALLOC_END),
 307 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 308                   MLG((unsigned long)vmemmap,
 309                       (unsigned long)vmemmap + VMEMMAP_SIZE),
 310                   MLM((unsigned long)virt_to_page(PAGE_OFFSET),
 311                       (unsigned long)virt_to_page(high_memory)),
 312 #endif
 313                   MLM((unsigned long)PCI_IOBASE, (unsigned long)PCI_IOBASE + SZ_16M),
 314                   MLK(FIXADDR_START, FIXADDR_TOP),
 315                   MLM(MODULES_VADDR, MODULES_END),
 316                   MLM(PAGE_OFFSET, (unsigned long)high_memory),
 317                   MLK_ROUNDUP(__init_begin, __init_end),
 318                   MLK_ROUNDUP(_text, _etext),
 319                   MLK_ROUNDUP(_sdata, _edata));
 320
 321 #undef MLK
 322 #undef MLM
 323 #undef MLK_ROUNDUP
 324
 325         /*
 326          * Check boundaries twice: Some fundamental inconsistencies can be
 327          * detected at build time already.
 328          */
 329 #ifdef CONFIG_COMPAT
 330         BUILD_BUG_ON(TASK_SIZE_32                       > TASK_SIZE_64);
 331 #endif
 332         BUILD_BUG_ON(TASK_SIZE_64                       > MODULES_VADDR);
 333         BUG_ON(TASK_SIZE_64                             > MODULES_VADDR);
 334
 335         if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 336                 extern int sysctl_overcommit_memory;
 337                 /*
 338                  * On a machine this small we won't get anywhere without
 339                  * overcommit, so turn it on by default.
 340                  */
 341                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 342         }
 343 }
 344
 345 void free_initmem(void)
 346 {
 347         fixup_init();
 348         free_initmem_default(0);
 349         free_alternatives_memory();
 350 }
 351
 352 #ifdef CONFIG_BLK_DEV_INITRD
 353
 354 static int keep_initrd;
 355
 356 void free_initrd_mem(unsigned long start, unsigned long end)
 357 {
 358         if (!keep_initrd) {
 359                 if (start == initrd_start)
 360                         start = round_down(start, PAGE_SIZE);
 361                 if (end == initrd_end)
 362                         end = round_up(end, PAGE_SIZE);
 363
 364                 free_reserved_area((void *)start, (void *)end, 0, "initrd");
 365         }
 366 }
 367
 368 static int __init keepinitrd_setup(char *__unused)
 369 {
 370         keep_initrd = 1;
 371         return 1;
 372 }
 373
 374 __setup("keepinitrd", keepinitrd_setup);
 375 #endif