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