memory.c

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/*
 * Carsten Langgaard, [email protected]
 * Copyright (C) 1999,2000 MIPS Technologies, Inc.  All rights reserved.
 * Portions copyright (C) 2009 Cisco Systems, Inc.
 *
 *  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.
 *
 * Apparently originally from arch/mips/malta-memory.c. Modified to work
 * with the PowerTV bootloader.
 */
#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>
#include <asm/mach-powertv/asic.h>
#include <asm/mach-powertv/ioremap.h>

#include "init.h"

/* Memory constants */
#define KIBIBYTE(n)     ((n) * 1024)    /* Number of kibibytes */
#define MEBIBYTE(n)     ((n) * KIBIBYTE(1024)) /* Number of mebibytes */
#define DEFAULT_MEMSIZE     MEBIBYTE(128)   /* If no memsize provided */

#define BLDR_SIZE   KIBIBYTE(256)       /* Memory reserved for bldr */
#define RV_SIZE     MEBIBYTE(4)     /* Size of reset vector */

#define LOW_MEM_END 0x20000000      /* Highest low memory address */
#define BLDR_ALIAS  0x10000000      /* Bootloader address */
#define RV_PHYS     0x1fc00000      /* Reset vector address */
#define LOW_RAM_END RV_PHYS         /* End of real RAM in low mem */

/*
 * Very low-level conversion from processor physical address to device
 * DMA address for the first bank of memory.
 */
#define PHYS_TO_DMA(paddr)  ((paddr) + (CONFIG_LOW_RAM_DMA - LOW_RAM_ALIAS))

unsigned long ptv_memsize;

/*
 * struct low_mem_reserved - Items in low memory that are reserved
 * @start:  Physical address of item
 * @size:   Size, in bytes, of this item
 * @is_aliased: True if this is RAM aliased from another location. If false,
 *      it is something other than aliased RAM and the RAM in the
 *      unaliased address is still visible outside of low memory.
 */
struct low_mem_reserved {
    phys_addr_t start;
    phys_addr_t size;
    bool        is_aliased;
};

/*
 * Must be in ascending address order
 */
struct low_mem_reserved low_mem_reserved[] = {
    {BLDR_ALIAS, BLDR_SIZE, true},  /* Bootloader RAM */
    {RV_PHYS, RV_SIZE, false},  /* Reset vector */
};

/*
 * struct mem_layout - layout of a piece of the system RAM
 * @phys:   Physical address of the start of this piece of RAM. This is the
 *      address at which both the processor and I/O devices see the
 *      RAM.
 * @alias:  Alias of this piece of memory in order to make it appear in
 *      the low memory part of the processor's address space. I/O
 *      devices don't see anything here.
 * @size:   Size, in bytes, of this piece of RAM
 */
struct mem_layout {
    phys_addr_t phys;
    phys_addr_t alias;
    phys_addr_t size;
};

/*
 * struct mem_layout_list - list descriptor for layouts of system RAM pieces
 * @family: Specifies the family being described
 * @n:      Number of &struct mem_layout elements
 * @layout: Pointer to the list of &mem_layout structures
 */
struct mem_layout_list {
    enum family_type    family;
    size_t          n;
    struct mem_layout   *layout;
};

static struct mem_layout f1500_layout[] = {
    {0x20000000, 0x10000000, MEBIBYTE(256)},
};

static struct mem_layout f4500_layout[] = {
    {0x40000000, 0x10000000, MEBIBYTE(256)},
    {0x20000000, 0x20000000, MEBIBYTE(32)},
};

static struct mem_layout f8500_layout[] = {
    {0x40000000, 0x10000000, MEBIBYTE(256)},
    {0x20000000, 0x20000000, MEBIBYTE(32)},
    {0x30000000, 0x30000000, MEBIBYTE(32)},
};

static struct mem_layout fx600_layout[] = {
    {0x20000000, 0x10000000, MEBIBYTE(256)},
    {0x60000000, 0x60000000, MEBIBYTE(128)},
};

static struct mem_layout_list layout_list[] = {
    {FAMILY_1500, ARRAY_SIZE(f1500_layout), f1500_layout},
    {FAMILY_1500VZE, ARRAY_SIZE(f1500_layout), f1500_layout},
    {FAMILY_1500VZF, ARRAY_SIZE(f1500_layout), f1500_layout},
    {FAMILY_4500, ARRAY_SIZE(f4500_layout), f4500_layout},
    {FAMILY_8500, ARRAY_SIZE(f8500_layout), f8500_layout},
    {FAMILY_8500RNG, ARRAY_SIZE(f8500_layout), f8500_layout},
    {FAMILY_4600, ARRAY_SIZE(fx600_layout), fx600_layout},
    {FAMILY_4600VZA, ARRAY_SIZE(fx600_layout), fx600_layout},
    {FAMILY_8600, ARRAY_SIZE(fx600_layout), fx600_layout},
    {FAMILY_8600VZB, ARRAY_SIZE(fx600_layout), fx600_layout},
};

/* If we can't determine the layout, use this */
static struct mem_layout default_layout[] = {
    {0x20000000, 0x10000000, MEBIBYTE(128)},
};

static __init void register_non_ram(void)
{
    int i;

    for (i = 0; i < ARRAY_SIZE(low_mem_reserved); i++)
        add_memory_region(low_mem_reserved[i].start,
            low_mem_reserved[i].size, BOOT_MEM_RESERVED);
}

static phys_addr_t get_memsize(void)
{
    static char cmdline[COMMAND_LINE_SIZE] __initdata;
    phys_addr_t memsize = 0;
    char *memsize_str;
    char *ptr;

    /* Check the command line first for a memsize directive */
    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 {
        /* otherwise look in the environment */
        memsize_str = prom_getenv("memsize");

        if (memsize_str != NULL) {
            pr_info("prom memsize = %s\n", memsize_str);
            memsize = simple_strtol(memsize_str, NULL, 0);
        }

        if (memsize == 0) {
            if (_prom_memsize != 0) {
                memsize = _prom_memsize;
                pr_info("_prom_memsize = 0x%x\n", memsize);
                /* add in memory that the bootloader doesn't
                 * report */
                memsize += BLDR_SIZE;
            } else {
                memsize = DEFAULT_MEMSIZE;
                pr_info("Memsize not passed by bootloader, "
                    "defaulting to 0x%x\n", memsize);
            }
        }
    }

    return memsize;
}

static __init phys_addr_t register_low_ram(phys_addr_t p, phys_addr_t n)
{
    phys_addr_t s;
    int i;
    phys_addr_t orig_n;

    orig_n = n;

    BUG_ON(p + n > RV_PHYS);

    for (i = 0; n != 0 && i < ARRAY_SIZE(low_mem_reserved); i++) {
        phys_addr_t start;
        phys_addr_t size;

        start = low_mem_reserved[i].start;
        size = low_mem_reserved[i].size;

        /* Handle memory before this low memory section */
        if (p < start) {
            phys_addr_t s;
            s = min(n, start - p);
            add_memory_region(p, s, BOOT_MEM_RAM);
            p += s;
            n -= s;
        }

        /* Handle the low memory section itself. If it's aliased,
         * we reduce the number of byes left, but if not, the RAM
         * is available elsewhere and we don't reduce the number of
         * bytes remaining. */
        if (p == start) {
            if (low_mem_reserved[i].is_aliased) {
                s = min(n, size);
                n -= s;
                p += s;
            } else
                p += n;
        }
    }

    return orig_n - n;
}

/*
 * register_ram - register real RAM
 * @p:  Address of memory as seen by devices
 * @alias:  If the memory is seen at an additional address by the processor,
 *      this will be the address, otherwise it is the same as @p.
 * @n:      Number of bytes in this section of memory
 */
static __init void register_ram(phys_addr_t p, phys_addr_t alias,
    phys_addr_t n)
{
    /*
     * If some or all of this memory has an alias, break it into the
     * aliased and non-aliased portion.
     */
    if (p != alias) {
        phys_addr_t alias_size;
        phys_addr_t registered;

        alias_size = min(n, LOW_RAM_END - alias);
        registered = register_low_ram(alias, alias_size);
        ioremap_add_map(alias, p, n);
        n -= registered;
        p += registered;
    }

#ifdef CONFIG_HIGHMEM
    if (n != 0) {
        add_memory_region(p, n, BOOT_MEM_RAM);
        ioremap_add_map(p, p, n);
    }
#endif
}

static __init void register_address_space(phys_addr_t memsize)
{
    int i;
    phys_addr_t size;
    size_t n;
    struct mem_layout *layout;
    enum family_type family;

    /*
     * Register all of the things that aren't available to the kernel as
     * memory.
     */
    register_non_ram();

    /* Find the appropriate memory description */
    family = platform_get_family();

    for (i = 0; i < ARRAY_SIZE(layout_list); i++) {
        if (layout_list[i].family == family)
            break;
    }

    if (i == ARRAY_SIZE(layout_list)) {
        n = ARRAY_SIZE(default_layout);
        layout = default_layout;
    } else {
        n = layout_list[i].n;
        layout = layout_list[i].layout;
    }

    for (i = 0; memsize != 0 && i < n; i++) {
        size = min(memsize, layout[i].size);
        register_ram(layout[i].phys, layout[i].alias, size);
        memsize -= size;
    }
}

void __init prom_meminit(void)
{
    ptv_memsize = get_memsize();
    register_address_space(ptv_memsize);
}

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);
    }
}