arch/mips/mti-sead3/sead3-memory.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
   7  */
   8 #include <linux/bootmem.h>
   9
  10 #include <asm/bootinfo.h>
  11 #include <asm/sections.h>
  12 #include <asm/mips-boards/prom.h>
  13
  14 enum yamon_memtypes {
  15         yamon_dontuse,
  16         yamon_prom,
  17         yamon_free,
  18 };
  19
  20 static struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];
  21
  22 /* determined physical memory size, not overridden by command line args  */
  23 unsigned long physical_memsize = 0L;
  24
  25 struct prom_pmemblock * __init prom_getmdesc(void)
  26 {
  27         char *memsize_str, *ptr;
  28         unsigned int memsize;
  29         static char cmdline[COMMAND_LINE_SIZE] __initdata;
  30         long val;
  31         int tmp;
  32
  33         /* otherwise look in the environment */
  34         memsize_str = prom_getenv("memsize");
  35         if (!memsize_str) {
  36                 pr_warn("memsize not set in boot prom, set to default 32Mb\n");
  37                 physical_memsize = 0x02000000;
  38         } else {
  39                 tmp = kstrtol(memsize_str, 0, &val);
  40                 physical_memsize = (unsigned long)val;
  41         }
  42
  43 #ifdef CONFIG_CPU_BIG_ENDIAN
  44         /* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
  45            word of physical memory */
  46         physical_memsize -= PAGE_SIZE;
  47 #endif
  48
  49         /* Check the command line for a memsize directive that overrides
  50            the physical/default amount */
  51         strcpy(cmdline, arcs_cmdline);
  52         ptr = strstr(cmdline, "memsize=");
  53         if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
  54                 ptr = strstr(ptr, " memsize=");
  55
  56         if (ptr)
  57                 memsize = memparse(ptr + 8, &ptr);
  58         else
  59                 memsize = physical_memsize;
  60
  61         memset(mdesc, 0, sizeof(mdesc));
  62
  63         mdesc[0].type = yamon_dontuse;
  64         mdesc[0].base = 0x00000000;
  65         mdesc[0].size = 0x00001000;
  66
  67         mdesc[1].type = yamon_prom;
  68         mdesc[1].base = 0x00001000;
  69         mdesc[1].size = 0x000ef000;
  70
  71         /*
  72          * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
  73          * south bridge and PCI access always forwarded to the ISA Bus and
  74          * BIOSCS# is always generated.
  75          * This mean that this area can't be used as DMA memory for PCI
  76          * devices.
  77          */
  78         mdesc[2].type = yamon_dontuse;
  79         mdesc[2].base = 0x000f0000;
  80         mdesc[2].size = 0x00010000;
  81
  82         mdesc[3].type = yamon_dontuse;
  83         mdesc[3].base = 0x00100000;
  84         mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) -
  85                 mdesc[3].base;
  86
  87         mdesc[4].type = yamon_free;
  88         mdesc[4].base = CPHYSADDR(PFN_ALIGN(&_end));
  89         mdesc[4].size = memsize - mdesc[4].base;
  90
  91         return &mdesc[0];
  92 }
  93
  94 static int __init prom_memtype_classify(unsigned int type)
  95 {
  96         switch (type) {
  97         case yamon_free:
  98                 return BOOT_MEM_RAM;
  99         case yamon_prom:
 100                 return BOOT_MEM_ROM_DATA;
 101         default:
 102                 return BOOT_MEM_RESERVED;
 103         }
 104 }
 105
 106 void __init prom_meminit(void)
 107 {
 108         struct prom_pmemblock *p;
 109
 110         p = prom_getmdesc();
 111
 112         while (p->size) {
 113                 long type;
 114                 unsigned long base, size;
 115
 116                 type = prom_memtype_classify(p->type);
 117                 base = p->base;
 118                 size = p->size;
 119
 120                 add_memory_region(base, size, type);
 121                 p++;
 122         }
 123 }
 124
 125 void __init prom_free_prom_memory(void)
 126 {
 127         unsigned long addr;
 128         int i;
 129
 130         for (i = 0; i < boot_mem_map.nr_map; i++) {
 131                 if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
 132                         continue;
 133
 134                 addr = boot_mem_map.map[i].addr;
 135                 free_init_pages("prom memory",
 136                                 addr, addr + boot_mem_map.map[i].size);
 137         }
 138 }