LXR linux/arch/arc/mm/init.c

   1/*
   2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/mm.h>
  11#include <linux/bootmem.h>
  12#include <linux/memblock.h>
  13#include <linux/swap.h>
  14#include <linux/module.h>
  15#include <asm/page.h>
  16#include <asm/pgalloc.h>
  17#include <asm/sections.h>
  18#include <asm/arcregs.h>
  19
  20pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  21char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  22EXPORT_SYMBOL(empty_zero_page);
  23
  24/* Default tot mem from .config */
  25static unsigned long arc_mem_sz = 0x20000000;  /* some default */
  26
  27/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  28static int __init setup_mem_sz(char *str)
  29{
  30        arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
  31
  32        /* early console might not be setup yet - it will show up later */
  33        pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
  34
  35        return 0;
  36}
  37early_param("mem", setup_mem_sz);
  38
  39void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  40{
  41        arc_mem_sz = size & PAGE_MASK;
  42        pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz));
  43}
  44
  45/*
  46 * First memory setup routine called from setup_arch()
  47 * 1. setup swapper's mm @init_mm
  48 * 2. Count the pages we have and setup bootmem allocator
  49 * 3. zone setup
  50 */
  51void __init setup_arch_memory(void)
  52{
  53        unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 };
  54        unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
  55
  56        init_mm.start_code = (unsigned long)_text;
  57        init_mm.end_code = (unsigned long)_etext;
  58        init_mm.end_data = (unsigned long)_edata;
  59        init_mm.brk = (unsigned long)_end;
  60
  61        /*
  62         * We do it here, so that memory is correctly instantiated
  63         * even if "mem=xxx" cmline over-ride is given and/or
  64         * DT has memory node. Each causes an update to @arc_mem_sz
  65         * and we finally add memory one here
  66         */
  67        memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
  68
  69        /*------------- externs in mm need setting up ---------------*/
  70
  71        /* first page of system - kernel .vector starts here */
  72        min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE);
  73
  74        /* Last usable page of low mem (no HIGHMEM yet for ARC port) */
  75        max_low_pfn = max_pfn = PFN_DOWN(end_mem);
  76
  77        max_mapnr = max_low_pfn - min_low_pfn;
  78
  79        /*------------- reserve kernel image -----------------------*/
  80        memblock_reserve(CONFIG_LINUX_LINK_BASE,
  81                         __pa(_end) - CONFIG_LINUX_LINK_BASE);
  82
  83        memblock_dump_all();
  84
  85        /*-------------- node setup --------------------------------*/
  86        memset(zones_size, 0, sizeof(zones_size));
  87        zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
  88
  89        /*
  90         * We can't use the helper free_area_init(zones[]) because it uses
  91         * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
  92         * when our kernel doesn't start at PAGE_OFFSET, i.e.
  93         * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
  94         */
  95        free_area_init_node(0,                  /* node-id */
  96                            zones_size,         /* num pages per zone */
  97                            min_low_pfn,        /* first pfn of node */
  98                            NULL);              /* NO holes */
  99}
 100
 101/*
 102 * mem_init - initializes memory
 103 *
 104 * Frees up bootmem
 105 * Calculates and displays memory available/used
 106 */
 107void __init mem_init(void)
 108{
 109        high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz);
 110        free_all_bootmem();
 111        mem_init_print_info(NULL);
 112}
 113
 114/*
 115 * free_initmem: Free all the __init memory.
 116 */
 117void __init_refok free_initmem(void)
 118{
 119        free_initmem_default(-1);
 120}
 121
 122#ifdef CONFIG_BLK_DEV_INITRD
 123void __init free_initrd_mem(unsigned long start, unsigned long end)
 124{
 125        free_reserved_area((void *)start, (void *)end, -1, "initrd");
 126}
 127#endif
 128
 129#ifdef CONFIG_OF_FLATTREE
 130void __init early_init_dt_setup_initrd_arch(u64 start, u64 end)
 131{
 132        pr_err("%s(%llx, %llx)\n", __func__, start, end);
 133}
 134#endif /* CONFIG_OF_FLATTREE */
 135