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 /*
  81  * Initialize memory pages.
  82  */
  83
  84 void __init mem_init(void)
  85 {
  86 #ifdef CONFIG_HIGHMEM
  87         unsigned long tmp;
  88
  89         reset_all_zones_managed_pages();
  90         for (tmp = max_low_pfn; tmp < max_pfn; tmp++)
  91                 free_highmem_page(pfn_to_page(tmp));
  92 #endif
  93
  94         max_mapnr = max_pfn - ARCH_PFN_OFFSET;
  95         high_memory = (void *)__va(max_low_pfn << PAGE_SHIFT);
  96
  97         free_all_bootmem();
  98
  99         mem_init_print_info(NULL);
 100         pr_info("virtual kernel memory layout:\n"
 101 #ifdef CONFIG_HIGHMEM
 102                 "    pkmap   : 0x%08lx - 0x%08lx  (%5lu kB)\n"
 103                 "    fixmap  : 0x%08lx - 0x%08lx  (%5lu kB)\n"
 104 #endif
 105 #ifdef CONFIG_MMU
 106                 "    vmalloc : 0x%08lx - 0x%08lx  (%5lu MB)\n"
 107 #endif
 108                 "    lowmem  : 0x%08lx - 0x%08lx  (%5lu MB)\n",
 109 #ifdef CONFIG_HIGHMEM
 110                 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 111                 (LAST_PKMAP*PAGE_SIZE) >> 10,
 112                 FIXADDR_START, FIXADDR_TOP,
 113                 (FIXADDR_TOP - FIXADDR_START) >> 10,
 114 #endif
 115 #ifdef CONFIG_MMU
 116                 VMALLOC_START, VMALLOC_END,
 117                 (VMALLOC_END - VMALLOC_START) >> 20,
 118                 PAGE_OFFSET, PAGE_OFFSET +
 119                 (max_low_pfn - min_low_pfn) * PAGE_SIZE,
 120 #else
 121                 min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE,
 122 #endif
 123                 ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20);
 124 }
 125
 126 #ifdef CONFIG_BLK_DEV_INITRD
 127 extern int initrd_is_mapped;
 128
 129 void free_initrd_mem(unsigned long start, unsigned long end)
 130 {
 131         if (initrd_is_mapped)
 132                 free_reserved_area((void *)start, (void *)end, -1, "initrd");
 133 }
 134 #endif
 135
 136 void free_initmem(void)
 137 {
 138         free_initmem_default(-1);
 139 }
 140
 141 static void __init parse_memmap_one(char *p)
 142 {
 143         char *oldp;
 144         unsigned long start_at, mem_size;
 145
 146         if (!p)
 147                 return;
 148
 149         oldp = p;
 150         mem_size = memparse(p, &p);
 151         if (p == oldp)
 152                 return;
 153
 154         switch (*p) {
 155         case '@':
 156                 start_at = memparse(p + 1, &p);
 157                 memblock_add(start_at, mem_size);
 158                 break;
 159
 160         case '$':
 161                 start_at = memparse(p + 1, &p);
 162                 memblock_reserve(start_at, mem_size);
 163                 break;
 164
 165         case 0:
 166                 memblock_reserve(mem_size, -mem_size);
 167                 break;
 168
 169         default:
 170                 pr_warn("Unrecognized memmap syntax: %s\n", p);
 171                 break;
 172         }
 173 }
 174
 175 static int __init parse_memmap_opt(char *str)
 176 {
 177         while (str) {
 178                 char *k = strchr(str, ',');
 179
 180                 if (k)
 181                         *k++ = 0;
 182
 183                 parse_memmap_one(str);
 184                 str = k;
 185         }
 186
 187         return 0;
 188 }
 189 early_param("memmap", parse_memmap_opt);