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 #include <linux/swiotlb.h>
  37
  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>
  43 #include <asm/tlb.h>
  44 #include <asm/alternative.h>
  45
  46 #include "mm.h"
  47
  48 phys_addr_t memstart_addr __read_mostly = 0;
  49 phys_addr_t arm64_dma_phys_limit __read_mostly;
  50
  51 #ifdef CONFIG_BLK_DEV_INITRD
  52 static int __init early_initrd(char *p)
  53 {
  54         unsigned long start, size;
  55         char *endp;
  56
  57         start = memparse(p, &endp);
  58         if (*endp == ',') {
  59                 size = memparse(endp + 1, NULL);
  60
  61                 initrd_start = (unsigned long)__va(start);
  62                 initrd_end = (unsigned long)__va(start + size);
  63         }
  64         return 0;
  65 }
  66 early_param("initrd", early_initrd);
  67 #endif
  68
  69 /*
  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
  72  * use a DMA offset.
  73  */
  74 static phys_addr_t max_zone_dma_phys(void)
  75 {
  76         phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
  77         return min(offset + (1ULL << 32), memblock_end_of_DRAM());
  78 }
  79
  80 static void __init zone_sizes_init(unsigned long min, unsigned long max)
  81 {
  82         struct memblock_region *reg;
  83         unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
  84         unsigned long max_dma = min;
  85
  86         memset(zone_size, 0, sizeof(zone_size));
  87
  88         /* 4GB maximum for 32-bit only capable devices */
  89         if (IS_ENABLED(CONFIG_ZONE_DMA)) {
  90                 max_dma = PFN_DOWN(arm64_dma_phys_limit);
  91                 zone_size[ZONE_DMA] = max_dma - min;
  92         }
  93         zone_size[ZONE_NORMAL] = max - max_dma;
  94
  95         memcpy(zhole_size, zone_size, sizeof(zhole_size));
  96
  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);
 100
 101                 if (start >= max)
 102                         continue;
 103
 104                 if (IS_ENABLED(CONFIG_ZONE_DMA) && start < max_dma) {
 105                         unsigned long dma_end = min(end, max_dma);
 106                         zhole_size[ZONE_DMA] -= dma_end - start;
 107                 }
 108
 109                 if (end > max_dma) {
 110                         unsigned long normal_end = min(end, max);
 111                         unsigned long normal_start = max(start, max_dma);
 112                         zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
 113                 }
 114         }
 115
 116         free_area_init_node(0, zone_size, min, zhole_size);
 117 }
 118
 119 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
 120 int pfn_valid(unsigned long pfn)
 121 {
 122         return memblock_is_memory(pfn << PAGE_SHIFT);
 123 }
 124 EXPORT_SYMBOL(pfn_valid);
 125 #endif
 126
 127 #ifndef CONFIG_SPARSEMEM
 128 static void arm64_memory_present(void)
 129 {
 130 }
 131 #else
 132 static void arm64_memory_present(void)
 133 {
 134         struct memblock_region *reg;
 135
 136         for_each_memblock(memory, reg)
 137                 memory_present(0, memblock_region_memory_base_pfn(reg),
 138                                memblock_region_memory_end_pfn(reg));
 139 }
 140 #endif
 141
 142 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
 143
 144 /*
 145  * Limit the memory size that was specified via FDT.
 146  */
 147 static int __init early_mem(char *p)
 148 {
 149         if (!p)
 150                 return 1;
 151
 152         memory_limit = memparse(p, &p) & PAGE_MASK;
 153         pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
 154
 155         return 0;
 156 }
 157 early_param("mem", early_mem);
 158
 159 void __init arm64_memblock_init(void)
 160 {
 161         memblock_enforce_memory_limit(memory_limit);
 162
 163         /*
 164          * Register the kernel text, kernel data, initrd, and initial
 165          * pagetables with memblock.
 166          */
 167         memblock_reserve(__pa(_text), _end - _text);
 168 #ifdef CONFIG_BLK_DEV_INITRD
 169         if (initrd_start)
 170                 memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
 171 #endif
 172
 173         early_init_fdt_scan_reserved_mem();
 174
 175         /* 4GB maximum for 32-bit only capable devices */
 176         if (IS_ENABLED(CONFIG_ZONE_DMA))
 177                 arm64_dma_phys_limit = max_zone_dma_phys();
 178         else
 179                 arm64_dma_phys_limit = PHYS_MASK + 1;
 180         dma_contiguous_reserve(arm64_dma_phys_limit);
 181
 182         memblock_allow_resize();
 183         memblock_dump_all();
 184 }
 185
 186 void __init bootmem_init(void)
 187 {
 188         unsigned long min, max;
 189
 190         min = PFN_UP(memblock_start_of_DRAM());
 191         max = PFN_DOWN(memblock_end_of_DRAM());
 192
 193         early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
 194
 195         /*
 196          * Sparsemem tries to allocate bootmem in memory_present(), so must be
 197          * done after the fixed reservations.
 198          */
 199         arm64_memory_present();
 200
 201         sparse_init();
 202         zone_sizes_init(min, max);
 203
 204         high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
 205         max_pfn = max_low_pfn = max;
 206 }
 207
 208 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 209 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 210 {
 211         struct page *start_pg, *end_pg;
 212         unsigned long pg, pgend;
 213
 214         /*
 215          * Convert start_pfn/end_pfn to a struct page pointer.
 216          */
 217         start_pg = pfn_to_page(start_pfn - 1) + 1;
 218         end_pg = pfn_to_page(end_pfn - 1) + 1;
 219
 220         /*
 221          * Convert to physical addresses, and round start upwards and end
 222          * downwards.
 223          */
 224         pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
 225         pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
 226
 227         /*
 228          * If there are free pages between these, free the section of the
 229          * memmap array.
 230          */
 231         if (pg < pgend)
 232                 free_bootmem(pg, pgend - pg);
 233 }
 234
 235 /*
 236  * The mem_map array can get very big. Free the unused area of the memory map.
 237  */
 238 static void __init free_unused_memmap(void)
 239 {
 240         unsigned long start, prev_end = 0;
 241         struct memblock_region *reg;
 242
 243         for_each_memblock(memory, reg) {
 244                 start = __phys_to_pfn(reg->base);
 245
 246 #ifdef CONFIG_SPARSEMEM
 247                 /*
 248                  * Take care not to free memmap entries that don't exist due
 249                  * to SPARSEMEM sections which aren't present.
 250                  */
 251                 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
 252 #endif
 253                 /*
 254                  * If we had a previous bank, and there is a space between the
 255                  * current bank and the previous, free it.
 256                  */
 257                 if (prev_end && prev_end < start)
 258                         free_memmap(prev_end, start);
 259
 260                 /*
 261                  * Align up here since the VM subsystem insists that the
 262                  * memmap entries are valid from the bank end aligned to
 263                  * MAX_ORDER_NR_PAGES.
 264                  */
 265                 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
 266                                  MAX_ORDER_NR_PAGES);
 267         }
 268
 269 #ifdef CONFIG_SPARSEMEM
 270         if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
 271                 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
 272 #endif
 273 }
 274 #endif  /* !CONFIG_SPARSEMEM_VMEMMAP */
 275
 276 /*
 277  * mem_init() marks the free areas in the mem_map and tells us how much memory
 278  * is free.  This is done after various parts of the system have claimed their
 279  * memory after the kernel image.
 280  */
 281 void __init mem_init(void)
 282 {
 283         swiotlb_init(1);
 284
 285         set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
 286
 287 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 288         free_unused_memmap();
 289 #endif
 290         /* this will put all unused low memory onto the freelists */
 291         free_all_bootmem();
 292
 293         mem_init_print_info(NULL);
 294
 295 #define MLK(b, t) b, t, ((t) - (b)) >> 10
 296 #define MLM(b, t) b, t, ((t) - (b)) >> 20
 297 #define MLG(b, t) b, t, ((t) - (b)) >> 30
 298 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
 299
 300         pr_notice("Virtual kernel memory layout:\n"
 301                   "    vmalloc : 0x%16lx - 0x%16lx   (%6ld GB)\n"
 302 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 303                   "    vmemmap : 0x%16lx - 0x%16lx   (%6ld GB maximum)\n"
 304                   "              0x%16lx - 0x%16lx   (%6ld MB actual)\n"
 305 #endif
 306                   "    fixed   : 0x%16lx - 0x%16lx   (%6ld KB)\n"
 307                   "    PCI I/O : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 308                   "    modules : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 309                   "    memory  : 0x%16lx - 0x%16lx   (%6ld MB)\n"
 310                   "      .init : 0x%p" " - 0x%p" "   (%6ld KB)\n"
 311                   "      .text : 0x%p" " - 0x%p" "   (%6ld KB)\n"
 312                   "      .data : 0x%p" " - 0x%p" "   (%6ld KB)\n",
 313                   MLG(VMALLOC_START, VMALLOC_END),
 314 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 315                   MLG((unsigned long)vmemmap,
 316                       (unsigned long)vmemmap + VMEMMAP_SIZE),
 317                   MLM((unsigned long)virt_to_page(PAGE_OFFSET),
 318                       (unsigned long)virt_to_page(high_memory)),
 319 #endif
 320                   MLK(FIXADDR_START, FIXADDR_TOP),
 321                   MLM(PCI_IO_START, PCI_IO_END),
 322                   MLM(MODULES_VADDR, MODULES_END),
 323                   MLM(PAGE_OFFSET, (unsigned long)high_memory),
 324                   MLK_ROUNDUP(__init_begin, __init_end),
 325                   MLK_ROUNDUP(_text, _etext),
 326                   MLK_ROUNDUP(_sdata, _edata));
 327
 328 #undef MLK
 329 #undef MLM
 330 #undef MLK_ROUNDUP
 331
 332         /*
 333          * Check boundaries twice: Some fundamental inconsistencies can be
 334          * detected at build time already.
 335          */
 336 #ifdef CONFIG_COMPAT
 337         BUILD_BUG_ON(TASK_SIZE_32                       > TASK_SIZE_64);
 338 #endif
 339         BUILD_BUG_ON(TASK_SIZE_64                       > MODULES_VADDR);
 340         BUG_ON(TASK_SIZE_64                             > MODULES_VADDR);
 341
 342         if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
 343                 extern int sysctl_overcommit_memory;
 344                 /*
 345                  * On a machine this small we won't get anywhere without
 346                  * overcommit, so turn it on by default.
 347                  */
 348                 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
 349         }
 350 }
 351
 352 void free_initmem(void)
 353 {
 354         fixup_init();
 355         free_initmem_default(0);
 356         free_alternatives_memory();
 357 }
 358
 359 #ifdef CONFIG_BLK_DEV_INITRD
 360
 361 static int keep_initrd __initdata;
 362
 363 void __init free_initrd_mem(unsigned long start, unsigned long end)
 364 {
 365         if (!keep_initrd)
 366                 free_reserved_area((void *)start, (void *)end, 0, "initrd");
 367 }
 368
 369 static int __init keepinitrd_setup(char *__unused)
 370 {
 371         keep_initrd = 1;
 372         return 1;
 373 }
 374
 375 __setup("keepinitrd", keepinitrd_setup);
 376 #endif