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