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malta-memory.c

/*
 * Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
 *
 * PROM library functions for acquiring/using memory descriptors given to
 * us from the YAMON.
 */
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/pfn.h>
#include <linux/string.h>

#include <asm/bootinfo.h>
#include <asm/page.h>
#include <asm/sections.h>

#include <asm/mips-boards/prom.h>

/*#define DEBUG*/

enum yamon_memtypes {
      yamon_dontuse,
      yamon_prom,
      yamon_free,
};
static struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];

#ifdef DEBUG
static char *mtypes[3] = {
      "Dont use memory",
      "YAMON PROM memory",
      "Free memmory",
};
#endif

/* determined physical memory size, not overridden by command line args  */
unsigned long physical_memsize = 0L;

static struct prom_pmemblock * __init prom_getmdesc(void)
{
      char *memsize_str;
      unsigned int memsize;
      char cmdline[CL_SIZE], *ptr;

      /* otherwise look in the environment */
      memsize_str = prom_getenv("memsize");
      if (!memsize_str) {
            printk(KERN_WARNING
                   "memsize not set in boot prom, set to default (32Mb)\n");
            physical_memsize = 0x02000000;
      } else {
#ifdef DEBUG
            pr_debug("prom_memsize = %s\n", memsize_str);
#endif
            physical_memsize = simple_strtol(memsize_str, NULL, 0);
      }

#ifdef CONFIG_CPU_BIG_ENDIAN
      /* SOC-it swaps, or perhaps doesn't swap, when DMA'ing the last
         word of physical memory */
      physical_memsize -= PAGE_SIZE;
#endif

      /* Check the command line for a memsize directive that overrides
         the physical/default amount */
      strcpy(cmdline, arcs_cmdline);
      ptr = strstr(cmdline, "memsize=");
      if (ptr && (ptr != cmdline) && (*(ptr - 1) != ' '))
            ptr = strstr(ptr, " memsize=");

      if (ptr)
            memsize = memparse(ptr + 8, &ptr);
      else
            memsize = physical_memsize;

      memset(mdesc, 0, sizeof(mdesc));

      mdesc[0].type = yamon_dontuse;
      mdesc[0].base = 0x00000000;
      mdesc[0].size = 0x00001000;

      mdesc[1].type = yamon_prom;
      mdesc[1].base = 0x00001000;
      mdesc[1].size = 0x000ef000;

      /*
       * The area 0x000f0000-0x000fffff is allocated for BIOS memory by the
       * south bridge and PCI access always forwarded to the ISA Bus and
       * BIOSCS# is always generated.
       * This mean that this area can't be used as DMA memory for PCI
       * devices.
       */
      mdesc[2].type = yamon_dontuse;
      mdesc[2].base = 0x000f0000;
      mdesc[2].size = 0x00010000;

      mdesc[3].type = yamon_dontuse;
      mdesc[3].base = 0x00100000;
      mdesc[3].size = CPHYSADDR(PFN_ALIGN((unsigned long)&_end)) - mdesc[3].base;

      mdesc[4].type = yamon_free;
      mdesc[4].base = CPHYSADDR(PFN_ALIGN(&_end));
      mdesc[4].size = memsize - mdesc[4].base;

      return &mdesc[0];
}

static int __init prom_memtype_classify(unsigned int type)
{
      switch (type) {
      case yamon_free:
            return BOOT_MEM_RAM;
      case yamon_prom:
            return BOOT_MEM_ROM_DATA;
      default:
            return BOOT_MEM_RESERVED;
      }
}

void __init prom_meminit(void)
{
      struct prom_pmemblock *p;

#ifdef DEBUG
      pr_debug("YAMON MEMORY DESCRIPTOR dump:\n");
      p = prom_getmdesc();
      while (p->size) {
            int i = 0;
            pr_debug("[%d,%p]: base<%08lx> size<%08lx> type<%s>\n",
                   i, p, p->base, p->size, mtypes[p->type]);
            p++;
            i++;
      }
#endif
      p = prom_getmdesc();

      while (p->size) {
            long type;
            unsigned long base, size;

            type = prom_memtype_classify(p->type);
            base = p->base;
            size = p->size;

            add_memory_region(base, size, type);
                p++;
      }
}

void __init prom_free_prom_memory(void)
{
      unsigned long addr;
      int i;

      for (i = 0; i < boot_mem_map.nr_map; i++) {
            if (boot_mem_map.map[i].type != BOOT_MEM_ROM_DATA)
                  continue;

            addr = boot_mem_map.map[i].addr;
            free_init_pages("prom memory",
                        addr, addr + boot_mem_map.map[i].size);
      }
}

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