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_BLK_DEV_INITRD
  14 #include <linux/initrd.h>
  15 #endif
  16 #include <linux/of_fdt.h>
  17 #include <linux/swap.h>
  18 #include <linux/module.h>
  19 #include <linux/highmem.h>
  20 #include <asm/page.h>
  21 #include <asm/pgalloc.h>
  22 #include <asm/sections.h>
  23 #include <asm/arcregs.h>
  24
  25 pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
  26 char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
  27 EXPORT_SYMBOL(empty_zero_page);
  28
  29 static const unsigned long low_mem_start = CONFIG_LINUX_LINK_BASE;
  30 static unsigned long low_mem_sz;
  31
  32 #ifdef CONFIG_HIGHMEM
  33 static unsigned long min_high_pfn, max_high_pfn;
  34 static u64 high_mem_start;
  35 static u64 high_mem_sz;
  36 #endif
  37
  38 #ifdef CONFIG_DISCONTIGMEM
  39 struct pglist_data node_data[MAX_NUMNODES] __read_mostly;
  40 EXPORT_SYMBOL(node_data);
  41 #endif
  42
  43 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  44 static int __init setup_mem_sz(char *str)
  45 {
  46         low_mem_sz = memparse(str, NULL) & PAGE_MASK;
  47
  48         /* early console might not be setup yet - it will show up later */
  49         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
  50
  51         return 0;
  52 }
  53 early_param("mem", setup_mem_sz);
  54
  55 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  56 {
  57         int in_use = 0;
  58
  59         if (!low_mem_sz) {
  60                 if (base != low_mem_start)
  61                         panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
  62
  63                 low_mem_sz = size;
  64                 in_use = 1;
  65         } else {
  66 #ifdef CONFIG_HIGHMEM
  67                 high_mem_start = base;
  68                 high_mem_sz = size;
  69                 in_use = 1;
  70 #endif
  71         }
  72
  73         pr_info("Memory @ %llx [%lldM] %s\n",
  74                 base, TO_MB(size), !in_use ? "Not used":"");
  75 }
  76
  77 #ifdef CONFIG_BLK_DEV_INITRD
  78 static int __init early_initrd(char *p)
  79 {
  80         unsigned long start, size;
  81         char *endp;
  82
  83         start = memparse(p, &endp);
  84         if (*endp == ',') {
  85                 size = memparse(endp + 1, NULL);
  86
  87                 initrd_start = (unsigned long)__va(start);
  88                 initrd_end = (unsigned long)__va(start + size);
  89         }
  90         return 0;
  91 }
  92 early_param("initrd", early_initrd);
  93 #endif
  94
  95 /*
  96  * First memory setup routine called from setup_arch()
  97  * 1. setup swapper's mm @init_mm
  98  * 2. Count the pages we have and setup bootmem allocator
  99  * 3. zone setup
 100  */
 101 void __init setup_arch_memory(void)
 102 {
 103         unsigned long zones_size[MAX_NR_ZONES];
 104         unsigned long zones_holes[MAX_NR_ZONES];
 105
 106         init_mm.start_code = (unsigned long)_text;
 107         init_mm.end_code = (unsigned long)_etext;
 108         init_mm.end_data = (unsigned long)_edata;
 109         init_mm.brk = (unsigned long)_end;
 110
 111         /* first page of system - kernel .vector starts here */
 112         min_low_pfn = ARCH_PFN_OFFSET;
 113
 114         /* Last usable page of low mem */
 115         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 116
 117 #ifdef CONFIG_FLATMEM
 118         /* pfn_valid() uses this */
 119         max_mapnr = max_low_pfn - min_low_pfn;
 120 #endif
 121
 122         /*------------- bootmem allocator setup -----------------------*/
 123
 124         /*
 125          * seed the bootmem allocator after any DT memory node parsing or
 126          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 127          *
 128          * Only low mem is added, otherwise we have crashes when allocating
 129          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 130          * avail memory, ending in highmem with a > 32-bit address. However
 131          * it then tries to memset it with a truncaed 32-bit handle, causing
 132          * the crash
 133          */
 134
 135         memblock_add_node(low_mem_start, low_mem_sz, 0);
 136         memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 137
 138 #ifdef CONFIG_BLK_DEV_INITRD
 139         if (initrd_start)
 140                 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 141 #endif
 142
 143         early_init_fdt_reserve_self();
 144         early_init_fdt_scan_reserved_mem();
 145
 146         memblock_dump_all();
 147
 148         /*----------------- node/zones setup --------------------------*/
 149         memset(zones_size, 0, sizeof(zones_size));
 150         memset(zones_holes, 0, sizeof(zones_holes));
 151
 152         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 153         zones_holes[ZONE_NORMAL] = 0;
 154
 155         /*
 156          * We can't use the helper free_area_init(zones[]) because it uses
 157          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
 158          * when our kernel doesn't start at PAGE_OFFSET, i.e.
 159          * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
 160          */
 161         free_area_init_node(0,                  /* node-id */
 162                             zones_size,         /* num pages per zone */
 163                             min_low_pfn,        /* first pfn of node */
 164                             zones_holes);       /* holes */
 165
 166 #ifdef CONFIG_HIGHMEM
 167         /*
 168          * Populate a new node with highmem
 169          *
 170          * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
 171          * than addresses in normal ala low memory (0x8000_0000 based).
 172          * Even with PAE, the huge peripheral space hole would waste a lot of
 173          * mem with single mem_map[]. This warrants a mem_map per region design.
 174          * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
 175          *
 176          * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
 177          * populated with normal memory zone while node 1 only has highmem
 178          */
 179         node_set_online(1);
 180
 181         min_high_pfn = PFN_DOWN(high_mem_start);
 182         max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 183
 184         zones_size[ZONE_NORMAL] = 0;
 185         zones_holes[ZONE_NORMAL] = 0;
 186
 187         zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
 188         zones_holes[ZONE_HIGHMEM] = 0;
 189
 190         free_area_init_node(1,                  /* node-id */
 191                             zones_size,         /* num pages per zone */
 192                             min_high_pfn,       /* first pfn of node */
 193                             zones_holes);       /* holes */
 194
 195         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 196         kmap_init();
 197 #endif
 198 }
 199
 200 /*
 201  * mem_init - initializes memory
 202  *
 203  * Frees up bootmem
 204  * Calculates and displays memory available/used
 205  */
 206 void __init mem_init(void)
 207 {
 208 #ifdef CONFIG_HIGHMEM
 209         unsigned long tmp;
 210
 211         reset_all_zones_managed_pages();
 212         for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
 213                 free_highmem_page(pfn_to_page(tmp));
 214 #endif
 215
 216         free_all_bootmem();
 217         mem_init_print_info(NULL);
 218 }
 219
 220 /*
 221  * free_initmem: Free all the __init memory.
 222  */
 223 void __init_refok free_initmem(void)
 224 {
 225         free_initmem_default(-1);
 226 }
 227
 228 #ifdef CONFIG_BLK_DEV_INITRD
 229 void __init free_initrd_mem(unsigned long start, unsigned long end)
 230 {
 231         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 232 }
 233 #endif