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/memblock.h>
  12 #ifdef CONFIG_BLK_DEV_INITRD
  13 #include <linux/initrd.h>
  14 #endif
  15 #include <linux/of_fdt.h>
  16 #include <linux/swap.h>
  17 #include <linux/module.h>
  18 #include <linux/highmem.h>
  19 #include <asm/page.h>
  20 #include <asm/pgalloc.h>
  21 #include <asm/sections.h>
  22 #include <asm/arcregs.h>
  23
  24 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  25 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  26 EXPORT_SYMBOL(empty_zero_page);
  27
  28 static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
  29 static unsigned long low_mem_sz;
  30
  31 #ifdef CONFIG_HIGHMEM
  32 static unsigned long min_high_pfn, max_high_pfn;
  33 static u64 high_mem_start;
  34 static u64 high_mem_sz;
  35 #endif
  36
  37 #ifdef CONFIG_DISCONTIGMEM
  38 struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
  39 EXPORT_SYMBOL(node_data);
  40 #endif
  41
  42 long __init arc_get_mem_sz(void)
  43 {
  44         return low_mem_sz;
  45 }
  46
  47 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  48 static int __init setup_mem_sz(char *str)
  49 {
  50         low_mem_sz = memparse(str, NULL) & PAGE_MASK;
  51
  52         /* early console might not be setup yet - it will show up later */
  53         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
  54
  55         return 0;
  56 }
  57 early_param("mem", setup_mem_sz);
  58
  59 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  60 {
  61         int in_use = 0;
  62
  63         if (!low_mem_sz) {
  64                 if (base != low_mem_start)
  65                         panic("CONFIG_LINUX_RAM_BASE != DT memory { }");
  66
  67                 low_mem_sz = size;
  68                 in_use = 1;
  69         } else {
  70 #ifdef CONFIG_HIGHMEM
  71                 high_mem_start = base;
  72                 high_mem_sz = size;
  73                 in_use = 1;
  74 #endif
  75         }
  76
  77         pr_info("Memory @ %llx [%lldM] %s\n",
  78                 base, TO_MB(size), !in_use ? "Not used":"");
  79 }
  80
  81 /*
  82  * First memory setup routine called from setup_arch()
  83  * 1. setup swapper's mm @init_mm
  84  * 2. Count the pages we have and setup bootmem allocator
  85  * 3. zone setup
  86  */
  87 void __init setup_arch_memory(void)
  88 {
  89         unsigned long zones_size[MAX_NR_ZONES];
  90         unsigned long zones_holes[MAX_NR_ZONES];
  91
  92         init_mm.start_code = (unsigned long)_text;
  93         init_mm.end_code = (unsigned long)_etext;
  94         init_mm.end_data = (unsigned long)_edata;
  95         init_mm.brk = (unsigned long)_end;
  96
  97         /* first page of system - kernel .vector starts here */
  98         min_low_pfn = ARCH_PFN_OFFSET;
  99
 100         /* Last usable page of low mem */
 101         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 102
 103 #ifdef CONFIG_FLATMEM
 104         /* pfn_valid() uses this */
 105         max_mapnr = max_low_pfn - min_low_pfn;
 106 #endif
 107
 108         /*------------- bootmem allocator setup -----------------------*/
 109
 110         /*
 111          * seed the bootmem allocator after any DT memory node parsing or
 112          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 113          *
 114          * Only low mem is added, otherwise we have crashes when allocating
 115          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 116          * avail memory, ending in highmem with a > 32-bit address. However
 117          * it then tries to memset it with a truncaed 32-bit handle, causing
 118          * the crash
 119          */
 120
 121         memblock_add_node(low_mem_start, low_mem_sz, 0);
 122         memblock_reserve(CONFIG_LINUX_LINK_BASE,
 123                          __pa(_end) - CONFIG_LINUX_LINK_BASE);
 124
 125 #ifdef CONFIG_BLK_DEV_INITRD
 126         if (phys_initrd_size) {
 127                 memblock_reserve(phys_initrd_start, phys_initrd_size);
 128                 initrd_start = (unsigned long)__va(phys_initrd_start);
 129                 initrd_end = initrd_start + phys_initrd_size;
 130         }
 131 #endif
 132
 133         early_init_fdt_reserve_self();
 134         early_init_fdt_scan_reserved_mem();
 135
 136         memblock_dump_all();
 137
 138         /*----------------- node/zones setup --------------------------*/
 139         memset(zones_size, 0, sizeof(zones_size));
 140         memset(zones_holes, 0, sizeof(zones_holes));
 141
 142         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 143         zones_holes[ZONE_NORMAL] = 0;
 144
 145         /*
 146          * We can't use the helper free_area_init(zones[]) because it uses
 147          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
 148          * when our kernel doesn't start at PAGE_OFFSET, i.e.
 149          * PAGE_OFFSET != CONFIG_LINUX_RAM_BASE
 150          */
 151         free_area_init_node(0,                  /* node-id */
 152                             zones_size,         /* num pages per zone */
 153                             min_low_pfn,        /* first pfn of node */
 154                             zones_holes);       /* holes */
 155
 156 #ifdef CONFIG_HIGHMEM
 157         /*
 158          * Populate a new node with highmem
 159          *
 160          * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
 161          * than addresses in normal ala low memory (0x8000_0000 based).
 162          * Even with PAE, the huge peripheral space hole would waste a lot of
 163          * mem with single mem_map[]. This warrants a mem_map per region design.
 164          * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
 165          *
 166          * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
 167          * populated with normal memory zone while node 1 only has highmem
 168          */
 169         node_set_online(1);
 170
 171         min_high_pfn = PFN_DOWN(high_mem_start);
 172         max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 173
 174         zones_size[ZONE_NORMAL] = 0;
 175         zones_holes[ZONE_NORMAL] = 0;
 176
 177         zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
 178         zones_holes[ZONE_HIGHMEM] = 0;
 179
 180         free_area_init_node(1,                  /* node-id */
 181                             zones_size,         /* num pages per zone */
 182                             min_high_pfn,       /* first pfn of node */
 183                             zones_holes);       /* holes */
 184
 185         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 186         kmap_init();
 187 #endif
 188 }
 189
 190 /*
 191  * mem_init - initializes memory
 192  *
 193  * Frees up bootmem
 194  * Calculates and displays memory available/used
 195  */
 196 void __init mem_init(void)
 197 {
 198 #ifdef CONFIG_HIGHMEM
 199         unsigned long tmp;
 200
 201         reset_all_zones_managed_pages();
 202         for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
 203                 free_highmem_page(pfn_to_page(tmp));
 204 #endif
 205
 206         memblock_free_all();
 207         mem_init_print_info(NULL);
 208 }