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 static 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 static 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                 printk(KERN_WARNING
  63                        "memsize not set in boot prom, set to default (32Mb)\n");
  64                 physical_memsize = 0x02000000;
  65         } else {
  66 #ifdef DEBUG
  67                 pr_debug("prom_memsize = %s\n", memsize_str);
  68 #endif
  69                 physical_memsize = simple_strtol(memsize_str, NULL, 0);
  70         }
  71
  72 #ifdef CONFIG_CPU_BIG_ENDIAN
  73         /* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
  74            word of physical memory */
  75         physical_memsize -= PAGE_SIZE;
  76 #endif
  77
  78         /* Check the command line for a memsize directive that overrides
  79            the physical/default amount */
  80         strcpy(cmdline, arcs_cmdline);
  81         ptr = strstr(cmdline, "memsize=");
  82         if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
  83                 ptr = strstr(ptr, " memsize=");
  84
  85         if (ptr)
  86                 memsize = memparse(ptr + 8, &ptr);
  87         else
  88                 memsize = physical_memsize;
  89
  90         memset(mdesc, 0, sizeof(mdesc));
  91
  92         mdesc[0].type = yamon_dontuse;
  93         mdesc[0].base = 0x00000000;
  94         mdesc[0].size = 0x00001000;
  95
  96         mdesc[1].type = yamon_prom;
  97         mdesc[1].base = 0x00001000;
  98         mdesc[1].size = 0x000ef000;
  99
 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
 111         mdesc[3].type = yamon_dontuse;
 112         mdesc[3].base = 0x00100000;
 113         mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) - mdesc[3].base;
 114
 115         mdesc[4].type = yamon_free;
 116         mdesc[4].base = CPHYSADDR(PFN_ALIGN(&_end));
 117         mdesc[4].size = memsize - mdesc[4].base;
 118
 119         return &mdesc[0];
 120 }
 121
 122 static int __init prom_memtype_classify(unsigned int type)
 123 {
 124         switch (type) {
 125         case yamon_free:
 126                 return BOOT_MEM_RAM;
 127         case yamon_prom:
 128                 return BOOT_MEM_ROM_DATA;
 129         default:
 130                 return BOOT_MEM_RESERVED;
 131         }
 132 }
 133
 134 void __init prom_meminit(void)
 135 {
 136         struct prom_pmemblock *p;
 137
 138 #ifdef DEBUG
 139         pr_debug("YAMON MEMORY DESCRIPTOR dump:\n");
 140         p = prom_getmdesc();
 141         while (p->size) {
 142                 int i = 0;
 143                 pr_debug("[%d,%p]: base<%08lx> size<%08lx> type<%s>\n",
 144                          i, p, p->base, p->size, mtypes[p->type]);
 145                 p++;
 146                 i++;
 147         }
 148 #endif
 149         p = prom_getmdesc();
 150
 151         while (p->size) {
 152                 long type;
 153                 unsigned long base, size;
 154
 155                 type = prom_memtype_classify(p->type);
 156                 base = p->base;
 157                 size = p->size;
 158
 159                 add_memory_region(base, size, type);
 160                 p++;
 161         }
 162 }
 163
 164 void __init prom_free_prom_memory(void)
 165 {
 166         unsigned long addr;
 167         int i;
 168
 169         for (i = 0; i < boot_mem_map.nr_map; i++) {
 170                 if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
 171                         continue;
 172
 173                 addr = boot_mem_map.map[i].addr;
 174                 free_init_pages("prom memory",
 175                                 addr, addr + boot_mem_map.map[i].size);
 176         }
 177 }