sead3-memory.c

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/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
 */
#include <linux/bootmem.h>

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

enum yamon_memtypes {
    yamon_dontuse,
    yamon_prom,
    yamon_free,
};

static struct prom_pmemblock mdesc[PROM_MAX_PMEMBLOCKS];

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

struct prom_pmemblock * __init prom_getmdesc(void)
{
    char *memsize_str, *ptr;
    unsigned int memsize;
    static char cmdline[COMMAND_LINE_SIZE] __initdata;
    long val;
    int tmp;

    /* otherwise look in the environment */
    memsize_str = prom_getenv("memsize");
    if (!memsize_str) {
        pr_warn("memsize not set in boot prom, set to default 32Mb\n");
        physical_memsize = 0x02000000;
    } else {
        tmp = kstrtol(memsize_str, 0, &val);
        physical_memsize = (unsigned long)val;
    }

#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;

    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);
    }
}