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
  20 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  21 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  22 EXPORT_SYMBOL(empty_zero_page);
  23
  24 /* Default tot mem from .config */
  25 static unsigned long arc_mem_sz = 0x20000000;  /* some default */
  26
  27 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  28 static 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 }
  37 early_param("mem", setup_mem_sz);
  38
  39 void __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  */
  51 void __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  */
 107 void __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  */
 117 void __init_refok free_initmem(void)
 118 {
 119         free_initmem_default(-1);
 120 }
 121
 122 #ifdef CONFIG_BLK_DEV_INITRD
 123 void __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
 130 void __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 */