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;
  34 static u64 high_mem_start;
  35 static u64 high_mem_sz;
  36 #endif
  37
  38 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  39 static int __init setup_mem_sz(char *str)
  40 {
  41         low_mem_sz = memparse(str, NULL) & PAGE_MASK;
  42
  43         /* early console might not be setup yet - it will show up later */
  44         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
  45
  46         return 0;
  47 }
  48 early_param("mem", setup_mem_sz);
  49
  50 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  51 {
  52         int in_use = 0;
  53
  54         if (!low_mem_sz) {
  55                 if (base != low_mem_start)
  56                         panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
  57
  58                 low_mem_sz = size;
  59                 in_use = 1;
  60         } else {
  61 #ifdef CONFIG_HIGHMEM
  62                 high_mem_start = base;
  63                 high_mem_sz = size;
  64                 in_use = 1;
  65 #endif
  66         }
  67
  68         pr_info("Memory @ %llx [%lldM] %s\n",
  69                 base, TO_MB(size), !in_use ? "Not used":"");
  70 }
  71
  72 #ifdef CONFIG_BLK_DEV_INITRD
  73 static int __init early_initrd(char *p)
  74 {
  75         unsigned long start, size;
  76         char *endp;
  77
  78         start = memparse(p, &endp);
  79         if (*endp == ',') {
  80                 size = memparse(endp + 1, NULL);
  81
  82                 initrd_start = (unsigned long)__va(start);
  83                 initrd_end = (unsigned long)__va(start + size);
  84         }
  85         return 0;
  86 }
  87 early_param("initrd", early_initrd);
  88 #endif
  89
  90 /*
  91  * First memory setup routine called from setup_arch()
  92  * 1. setup swapper's mm @init_mm
  93  * 2. Count the pages we have and setup bootmem allocator
  94  * 3. zone setup
  95  */
  96 void __init setup_arch_memory(void)
  97 {
  98         unsigned long zones_size[MAX_NR_ZONES];
  99         unsigned long zones_holes[MAX_NR_ZONES];
 100
 101         init_mm.start_code = (unsigned long)_text;
 102         init_mm.end_code = (unsigned long)_etext;
 103         init_mm.end_data = (unsigned long)_edata;
 104         init_mm.brk = (unsigned long)_end;
 105
 106         /* first page of system - kernel .vector starts here */
 107         min_low_pfn = ARCH_PFN_OFFSET;
 108
 109         /* Last usable page of low mem */
 110         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 111
 112 #ifdef CONFIG_HIGHMEM
 113         min_high_pfn = PFN_DOWN(high_mem_start);
 114         max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 115 #endif
 116
 117         max_mapnr = max_pfn - min_low_pfn;
 118
 119         /*------------- bootmem allocator setup -----------------------*/
 120
 121         /*
 122          * seed the bootmem allocator after any DT memory node parsing or
 123          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 124          *
 125          * Only low mem is added, otherwise we have crashes when allocating
 126          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 127          * avail memory, ending in highmem with a > 32-bit address. However
 128          * it then tries to memset it with a truncaed 32-bit handle, causing
 129          * the crash
 130          */
 131
 132         memblock_add(low_mem_start, low_mem_sz);
 133         memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 134
 135 #ifdef CONFIG_BLK_DEV_INITRD
 136         if (initrd_start)
 137                 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 138 #endif
 139
 140         early_init_fdt_reserve_self();
 141         early_init_fdt_scan_reserved_mem();
 142
 143         memblock_dump_all();
 144
 145         /*----------------- node/zones setup --------------------------*/
 146         memset(zones_size, 0, sizeof(zones_size));
 147         memset(zones_holes, 0, sizeof(zones_holes));
 148
 149         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 150         zones_holes[ZONE_NORMAL] = 0;
 151
 152 #ifdef CONFIG_HIGHMEM
 153         zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
 154
 155         /* This handles the peripheral address space hole */
 156         zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
 157 #endif
 158
 159         /*
 160          * We can't use the helper free_area_init(zones[]) because it uses
 161          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
 162          * when our kernel doesn't start at PAGE_OFFSET, i.e.
 163          * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
 164          */
 165         free_area_init_node(0,                  /* node-id */
 166                             zones_size,         /* num pages per zone */
 167                             min_low_pfn,        /* first pfn of node */
 168                             zones_holes);       /* holes */
 169
 170 #ifdef CONFIG_HIGHMEM
 171         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 172         kmap_init();
 173 #endif
 174 }
 175
 176 /*
 177  * mem_init - initializes memory
 178  *
 179  * Frees up bootmem
 180  * Calculates and displays memory available/used
 181  */
 182 void __init mem_init(void)
 183 {
 184 #ifdef CONFIG_HIGHMEM
 185         unsigned long tmp;
 186
 187         reset_all_zones_managed_pages();
 188         for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
 189                 free_highmem_page(pfn_to_page(tmp));
 190 #endif
 191
 192         free_all_bootmem();
 193         mem_init_print_info(NULL);
 194 }
 195
 196 /*
 197  * free_initmem: Free all the __init memory.
 198  */
 199 void __init_refok free_initmem(void)
 200 {
 201         free_initmem_default(-1);
 202 }
 203
 204 #ifdef CONFIG_BLK_DEV_INITRD
 205 void __init free_initrd_mem(unsigned long start, unsigned long end)
 206 {
 207         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 208 }
 209 #endif