arch/xtensa/mm/init.c

   1 /*
   2  * arch/xtensa/mm/init.c
   3  *
   4  * Derived from MIPS, PPC.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  *
  10  * Copyright (C) 2001 - 2005 Tensilica Inc.
  11  * Copyright (C) 2014 - 2016 Cadence Design Systems Inc.
  12  *
  13  * Chris Zankel <chris@zankel.net>
  14  * Joe Taylor   <joe@tensilica.com, joetylr@yahoo.com>
  15  * Marc Gauthier
  16  * Kevin Chea
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/errno.h>
  21 #include <linux/bootmem.h>
  22 #include <linux/gfp.h>
  23 #include <linux/highmem.h>
  24 #include <linux/swap.h>
  25 #include <linux/mman.h>
  26 #include <linux/nodemask.h>
  27 #include <linux/mm.h>
  28 #include <linux/of_fdt.h>
  29 #include <linux/dma-contiguous.h>
  30
  31 #include <asm/bootparam.h>
  32 #include <asm/page.h>
  33 #include <asm/sections.h>
  34 #include <asm/sysmem.h>
  35
  36 /*
  37  * Initialize the bootmem system and give it all low memory we have available.
  38  */
  39
  40 void __init bootmem_init(void)
  41 {
  42         /* Reserve all memory below PHYS_OFFSET, as memory
  43          * accounting doesn't work for pages below that address.
  44          *
  45          * If PHYS_OFFSET is zero reserve page at address 0:
  46          * successfull allocations should never return NULL.
  47          */
  48         if (PHYS_OFFSET)
  49                 memblock_reserve(0, PHYS_OFFSET);
  50         else
  51                 memblock_reserve(0, 1);
  52
  53         early_init_fdt_scan_reserved_mem();
  54
  55         if (!memblock_phys_mem_size())
  56                 panic("No memory found!\n");
  57
  58         min_low_pfn = PFN_UP(memblock_start_of_DRAM());
  59         min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET));
  60         max_pfn = PFN_DOWN(memblock_end_of_DRAM());
  61         max_low_pfn = min(max_pfn, MAX_LOW_PFN);
  62
  63         memblock_set_current_limit(PFN_PHYS(max_low_pfn));
  64         dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
  65
  66         memblock_dump_all();
  67 }
  68
  69
  70 void __init zones_init(void)
  71 {
  72         /* All pages are DMA-able, so we put them all in the DMA zone. */
  73         unsigned long zones_size[MAX_NR_ZONES] = {
  74                 [ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET,
  75 #ifdef CONFIG_HIGHMEM
  76                 [ZONE_HIGHMEM] = max_pfn - max_low_pfn,
  77 #endif
  78         };
  79         free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
  80 }
  81
  82 #ifdef CONFIG_HIGHMEM
  83 static void __init free_area_high(unsigned long pfn, unsigned long end)
  84 {
  85         for (; pfn < end; pfn++)
  86                 free_highmem_page(pfn_to_page(pfn));
  87 }
  88
  89 static void __init free_highpages(void)
  90 {
  91         unsigned long max_low = max_low_pfn;
  92         struct memblock_region *mem, *res;
  93
  94         reset_all_zones_managed_pages();
  95         /* set highmem page free */
  96         for_each_memblock(memory, mem) {
  97                 unsigned long start = memblock_region_memory_base_pfn(mem);
  98                 unsigned long end = memblock_region_memory_end_pfn(mem);
  99
 100                 /* Ignore complete lowmem entries */
 101                 if (end <= max_low)
 102                         continue;
 103
 104                 if (memblock_is_nomap(mem))
 105                         continue;
 106
 107                 /* Truncate partial highmem entries */
 108                 if (start < max_low)
 109                         start = max_low;
 110
 111                 /* Find and exclude any reserved regions */
 112                 for_each_memblock(reserved, res) {
 113                         unsigned long res_start, res_end;
 114
 115                         res_start = memblock_region_reserved_base_pfn(res);
 116                         res_end = memblock_region_reserved_end_pfn(res);
 117
 118                         if (res_end < start)
 119                                 continue;
 120                         if (res_start < start)
 121                                 res_start = start;
 122                         if (res_start > end)
 123                                 res_start = end;
 124                         if (res_end > end)
 125                                 res_end = end;
 126                         if (res_start != start)
 127                                 free_area_high(start, res_start);
 128                         start = res_end;
 129                         if (start == end)
 130                                 break;
 131                 }
 132
 133                 /* And now free anything which remains */
 134                 if (start < end)
 135                         free_area_high(start, end);
 136         }
 137 }
 138 #else
 139 static void __init free_highpages(void)
 140 {
 141 }
 142 #endif
 143
 144 /*
 145  * Initialize memory pages.
 146  */
 147
 148 void __init mem_init(void)
 149 {
 150         free_highpages();
 151
 152         max_mapnr = max_pfn - ARCH_PFN_OFFSET;
 153         high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
 154
 155         free_all_bootmem();
 156
 157         mem_init_print_info(NULL);
 158         pr_info("virtual kernel memory layout:\n"
 159 #ifdef CONFIG_HIGHMEM
 160                 "    pkmap   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
 161                 "    fixmap  : 0x%08lx - 0x%08lx  (%5lu kB)\n"
 162 #endif
 163 #ifdef CONFIG_MMU
 164                 "    vmalloc : 0x%08lx - 0x%08lx  (%5lu MB)\n"
 165 #endif
 166                 "    lowmem  : 0x%08lx - 0x%08lx  (%5lu MB)\n",
 167 #ifdef CONFIG_HIGHMEM
 168                 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 169                 (LAST_PKMAP*PAGE_SIZE) >> 10,
 170                 FIXADDR_START, FIXADDR_TOP,
 171                 (FIXADDR_TOP - FIXADDR_START) >> 10,
 172 #endif
 173 #ifdef CONFIG_MMU
 174                 VMALLOC_START, VMALLOC_END,
 175                 (VMALLOC_END - VMALLOC_START) >> 20,
 176                 PAGE_OFFSET, PAGE_OFFSET +
 177                 (max_low_pfn - min_low_pfn) * PAGE_SIZE,
 178 #else
 179                 min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
 180 #endif
 181                 ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20);
 182 }
 183
 184 #ifdef CONFIG_BLK_DEV_INITRD
 185 extern int initrd_is_mapped;
 186
 187 void free_initrd_mem(unsigned long start, unsigned long end)
 188 {
 189         if (initrd_is_mapped)
 190                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 191 }
 192 #endif
 193
 194 void free_initmem(void)
 195 {
 196         free_initmem_default(-1);
 197 }
 198
 199 static void __init parse_memmap_one(char *p)
 200 {
 201         char *oldp;
 202         unsigned long start_at, mem_size;
 203
 204         if (!p)
 205                 return;
 206
 207         oldp = p;
 208         mem_size = memparse(p, &p);
 209         if (p == oldp)
 210                 return;
 211
 212         switch (*p) {
 213         case '@':
 214                 start_at = memparse(p + 1, &p);
 215                 memblock_add(start_at, mem_size);
 216                 break;
 217
 218         case '$':
 219                 start_at = memparse(p + 1, &p);
 220                 memblock_reserve(start_at, mem_size);
 221                 break;
 222
 223         case 0:
 224                 memblock_reserve(mem_size, -mem_size);
 225                 break;
 226
 227         default:
 228                 pr_warn("Unrecognized memmap syntax: %s\n", p);
 229                 break;
 230         }
 231 }
 232
 233 static int __init parse_memmap_opt(char *str)
 234 {
 235         while (str) {
 236                 char *k = strchr(str, ',');
 237
 238                 if (k)
 239                         *k++ = 0;
 240
 241                 parse_memmap_one(str);
 242                 str = k;
 243         }
 244
 245         return 0;
 246 }
 247 early_param("memmap", parse_memmap_opt);