malta-memory.c

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/*
 * Carsten Langgaard, [email protected]
 * 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 memory",
};
#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 *ptr;
    static char cmdline[COMMAND_LINE_SIZE] __initdata;

    /* 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);
    }
}