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 #ifdef CONFIG_BLOCK_DEV_RAM
  14 #include <linux/blk.h>
  15 #endif
  16 #include <linux/swap.h>
  17 #include <linux/module.h>
  18 #include <asm/page.h>
  19 #include <asm/pgalloc.h>
  20 #include <asm/sections.h>
  21 #include <asm/arcregs.h>
  22
  23 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  24 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  25 EXPORT_SYMBOL(empty_zero_page);
  26
  27 /* Default tot mem from .config */
  28 static unsigned long arc_mem_sz = 0x20000000;  /* some default */
  29
  30 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  31 static int __init setup_mem_sz(char *str)
  32 {
  33         arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
  34
  35         /* early console might not be setup yet - it will show up later */
  36         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
  37
  38         return 0;
  39 }
  40 early_param("mem", setup_mem_sz);
  41
  42 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  43 {
  44         arc_mem_sz = size & PAGE_MASK;
  45         pr_info("Memory size set via devicetree %ldM\n", TO_MB(arc_mem_sz));
  46 }
  47
  48 /*
  49  * First memory setup routine called from setup_arch()
  50  * 1. setup swapper's mm @init_mm
  51  * 2. Count the pages we have and setup bootmem allocator
  52  * 3. zone setup
  53  */
  54 void __init setup_arch_memory(void)
  55 {
  56         unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 };
  57         unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
  58
  59         init_mm.start_code = (unsigned long)_text;
  60         init_mm.end_code = (unsigned long)_etext;
  61         init_mm.end_data = (unsigned long)_edata;
  62         init_mm.brk = (unsigned long)_end;
  63
  64         /*
  65          * We do it here, so that memory is correctly instantiated
  66          * even if "mem=xxx" cmline over-ride is given and/or
  67          * DT has memory node. Each causes an update to @arc_mem_sz
  68          * and we finally add memory one here
  69          */
  70         memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
  71
  72         /*------------- externs in mm need setting up ---------------*/
  73
  74         /* first page of system - kernel .vector starts here */
  75         min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE);
  76
  77         /* Last usable page of low mem (no HIGHMEM yet for ARC port) */
  78         max_low_pfn = max_pfn = PFN_DOWN(end_mem);
  79
  80         max_mapnr = num_physpages = max_low_pfn - min_low_pfn;
  81
  82         /*------------- reserve kernel image -----------------------*/
  83         memblock_reserve(CONFIG_LINUX_LINK_BASE,
  84                          __pa(_end) - CONFIG_LINUX_LINK_BASE);
  85
  86         memblock_dump_all();
  87
  88         /*-------------- node setup --------------------------------*/
  89         memset(zones_size, 0, sizeof(zones_size));
  90         zones_size[ZONE_NORMAL] = num_physpages;
  91
  92         /*
  93          * We can't use the helper free_area_init(zones[]) because it uses
  94          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
  95          * when our kernel doesn't start at PAGE_OFFSET, i.e.
  96          * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
  97          */
  98         free_area_init_node(0,                  /* node-id */
  99                             zones_size,         /* num pages per zone */
 100                             min_low_pfn,        /* first pfn of node */
 101                             NULL);              /* NO holes */
 102 }
 103
 104 /*
 105  * mem_init - initializes memory
 106  *
 107  * Frees up bootmem
 108  * Calculates and displays memory available/used
 109  */
 110 void __init mem_init(void)
 111 {
 112         int codesize, datasize, initsize, reserved_pages, free_pages;
 113         int tmp;
 114
 115         high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz);
 116
 117         totalram_pages = free_all_bootmem();
 118
 119         /* count all reserved pages [kernel code/data/mem_map..] */
 120         reserved_pages = 0;
 121         for (tmp = 0; tmp < max_mapnr; tmp++)
 122                 if (PageReserved(mem_map + tmp))
 123                         reserved_pages++;
 124
 125         /* XXX: nr_free_pages() is equivalent */
 126         free_pages = max_mapnr - reserved_pages;
 127
 128         /*
 129          * For the purpose of display below, split the "reserve mem"
 130          * kernel code/data is already shown explicitly,
 131          * Show any other reservations (mem_map[ ] et al)
 132          */
 133         reserved_pages -= (((unsigned int)_end - CONFIG_LINUX_LINK_BASE) >>
 134                                                                 PAGE_SHIFT);
 135
 136         codesize = _etext - _text;
 137         datasize = _end - _etext;
 138         initsize = __init_end - __init_begin;
 139
 140         pr_info("Memory Available: %dM / %ldM (%dK code, %dK data, %dK init, %dK reserv)\n",
 141                 PAGES_TO_MB(free_pages),
 142                 TO_MB(arc_mem_sz),
 143                 TO_KB(codesize), TO_KB(datasize), TO_KB(initsize),
 144                 PAGES_TO_KB(reserved_pages));
 145 }
 146
 147 /*
 148  * free_initmem: Free all the __init memory.
 149  */
 150 void __init_refok free_initmem(void)
 151 {
 152         free_initmem_default(0);
 153 }
 154
 155 #ifdef CONFIG_BLK_DEV_INITRD
 156 void __init free_initrd_mem(unsigned long start, unsigned long end)
 157 {
 158         free_reserved_area(start, end, 0, "initrd");
 159 }
 160 #endif
 161
 162 #ifdef CONFIG_OF_FLATTREE
 163 void __init early_init_dt_setup_initrd_arch(unsigned long start,
 164                                             unsigned long end)
 165 {
 166         pr_err("%s(%lx, %lx)\n", __func__, start, end);
 167 }
 168 #endif /* CONFIG_OF_FLATTREE */