arch/mips/mips-boards/generic/memory.c

   1 /*
   2  * Carsten Langgaard, carstenl@mips.com
   3  * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17  *
  18  * PROM library functions for acquiring/using memory descriptors given to
  19  * us from the YAMON.
  20  */
  21 #include <linux/init.h>
  22 #include <linux/mm.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/pfn.h>
  25 #include <linux/string.h>
  26
  27 #include <asm/bootinfo.h>
  28 #include <asm/page.h>
  29 #include <asm/sections.h>
  30
  31 #include <asm/mips-boards/prom.h>
  32
  33 /*#define DEBUG*/
  34
  35 enum yamon_memtypes {
  36         yamon_dontuse,
  37         yamon_prom,
  38         yamon_free,
  39 };
  40 struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];
  41
  42 #ifdef DEBUG
  43 static char *mtypes[3] = {
  44         "Dont use memory",
  45         "YAMON PROM memory",
  46         "Free memmory",
  47 };
  48 #endif
  49
  50 /* determined physical memory size, not overridden by command line args  */
  51 unsigned long physical_memsize = 0L;
  52
  53 struct prom_pmemblock * __init prom_getmdesc(void)
  54 {
  55         char *memsize_str;
  56         unsigned int memsize;
  57         char cmdline[CL_SIZE], *ptr;
  58
  59         /* otherwise look in the environment */
  60         memsize_str = prom_getenv("memsize");
  61         if (!memsize_str) {
  62                 prom_printf("memsize not set in boot prom, set to default (32Mb)\n");
  63                 physical_memsize = 0x02000000;
  64         } else {
  65 #ifdef DEBUG
  66                 prom_printf("prom_memsize = %s\n", memsize_str);
  67 #endif
  68                 physical_memsize = simple_strtol(memsize_str, NULL, 0);
  69         }
  70
  71 #ifdef CONFIG_CPU_BIG_ENDIAN
  72         /* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
  73            word of physical memory */
  74         physical_memsize -= PAGE_SIZE;
  75 #endif
  76
  77         /* Check the command line for a memsize directive that overrides
  78            the physical/default amount */
  79         strcpy(cmdline, arcs_cmdline);
  80         ptr = strstr(cmdline, "memsize=");
  81         if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
  82                 ptr = strstr(ptr, " memsize=");
  83
  84         if (ptr)
  85                 memsize = memparse(ptr + 8, &ptr);
  86         else
  87                 memsize = physical_memsize;
  88
  89         memset(mdesc, 0, sizeof(mdesc));
  90
  91         mdesc[0].type = yamon_dontuse;
  92         mdesc[0].base = 0x00000000;
  93         mdesc[0].size = 0x00001000;
  94
  95         mdesc[1].type = yamon_prom;
  96         mdesc[1].base = 0x00001000;
  97         mdesc[1].size = 0x000ef000;
  98
  99 #ifdef CONFIG_MIPS_MALTA
 100         /*
 101          * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
 102          * south bridge and PCI access always forwarded to the ISA Bus and
 103          * BIOSCS# is always generated.
 104          * This mean that this area can't be used as DMA memory for PCI
 105          * devices.
 106          */
 107         mdesc[2].type = yamon_dontuse;
 108         mdesc[2].base = 0x000f0000;
 109         mdesc[2].size = 0x00010000;
 110 #else
 111         mdesc[2].type = yamon_prom;
 112         mdesc[2].base = 0x000f0000;
 113         mdesc[2].size = 0x00010000;
 114 #endif
 115
 116         mdesc[3].type = yamon_dontuse;
 117         mdesc[3].base = 0x00100000;
 118         mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) - mdesc[3].base;
 119
 120         mdesc[4].type = yamon_free;
 121         mdesc[4].base = CPHYSADDR(PFN_ALIGN(&_end));
 122         mdesc[4].size = memsize - mdesc[4].base;
 123
 124         return &mdesc[0];
 125 }
 126
 127 static int __init prom_memtype_classify (unsigned int type)
 128 {
 129         switch (type) {
 130         case yamon_free:
 131                 return BOOT_MEM_RAM;
 132         case yamon_prom:
 133                 return BOOT_MEM_ROM_DATA;
 134         default:
 135                 return BOOT_MEM_RESERVED;
 136         }
 137 }
 138
 139 void __init prom_meminit(void)
 140 {
 141         struct prom_pmemblock *p;
 142
 143 #ifdef DEBUG
 144         prom_printf("YAMON MEMORY DESCRIPTOR dump:\n");
 145         p = prom_getmdesc();
 146         while (p->size) {
 147                 int i = 0;
 148                 prom_printf("[%d,%p]: base<%08lx> size<%08lx> type<%s>\n",
 149                             i, p, p->base, p->size, mtypes[p->type]);
 150                 p++;
 151                 i++;
 152         }
 153 #endif
 154         p = prom_getmdesc();
 155
 156         while (p->size) {
 157                 long type;
 158                 unsigned long base, size;
 159
 160                 type = prom_memtype_classify (p->type);
 161                 base = p->base;
 162                 size = p->size;
 163
 164                 add_memory_region(base, size, type);
 165                 p++;
 166         }
 167 }
 168
 169 unsigned long __init prom_free_prom_memory(void)
 170 {
 171         unsigned long freed = 0;
 172         unsigned long addr;
 173         int i;
 174
 175         for (i = 0; i < boot_mem_map.nr_map; i++) {
 176                 if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
 177                         continue;
 178
 179                 addr = boot_mem_map.map[i].addr;
 180                 while (addr < boot_mem_map.map[i].addr
 181                               + boot_mem_map.map[i].size) {
 182                         ClearPageReserved(virt_to_page(__va(addr)));
 183                         init_page_count(virt_to_page(__va(addr)));
 184                         free_page((unsigned long)__va(addr));
 185                         addr += PAGE_SIZE;
 186                         freed += PAGE_SIZE;
 187                 }
 188         }
 189         printk("Freeing prom memory: %ldkb freed\n", freed >> 10);
 190
 191         return freed;
 192 }