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/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_LINK_BASE;
  29 static unsigned long low_mem_sz;
  30
  31 #ifdef CONFIG_HIGHMEM
  32 static unsigned long min_high_pfn;
  33 static u64 high_mem_start;
  34 static u64 high_mem_sz;
  35 #endif
  36
  37 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  38 static int __init setup_mem_sz(char *str)
  39 {
  40         low_mem_sz = memparse(str, NULL) & PAGE_MASK;
  41
  42         /* early console might not be setup yet - it will show up later */
  43         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
  44
  45         return 0;
  46 }
  47 early_param("mem", setup_mem_sz);
  48
  49 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  50 {
  51         int in_use = 0;
  52
  53         if (!low_mem_sz) {
  54                 BUG_ON(base != low_mem_start);
  55                 low_mem_sz = size;
  56                 in_use = 1;
  57         } else {
  58 #ifdef CONFIG_HIGHMEM
  59                 high_mem_start = base;
  60                 high_mem_sz = size;
  61                 in_use = 1;
  62 #endif
  63         }
  64
  65         pr_info("Memory @ %llx [%lldM] %s\n",
  66                 base, TO_MB(size), !in_use ? "Not used":"");
  67 }
  68
  69 #ifdef CONFIG_BLK_DEV_INITRD
  70 static int __init early_initrd(char *p)
  71 {
  72         unsigned long start, size;
  73         char *endp;
  74
  75         start = memparse(p, &endp);
  76         if (*endp == ',') {
  77                 size = memparse(endp + 1, NULL);
  78
  79                 initrd_start = (unsigned long)__va(start);
  80                 initrd_end = (unsigned long)__va(start + size);
  81         }
  82         return 0;
  83 }
  84 early_param("initrd", early_initrd);
  85 #endif
  86
  87 /*
  88  * First memory setup routine called from setup_arch()
  89  * 1. setup swapper's mm @init_mm
  90  * 2. Count the pages we have and setup bootmem allocator
  91  * 3. zone setup
  92  */
  93 void __init setup_arch_memory(void)
  94 {
  95         unsigned long zones_size[MAX_NR_ZONES];
  96         unsigned long zones_holes[MAX_NR_ZONES];
  97
  98         init_mm.start_code = (unsigned long)_text;
  99         init_mm.end_code = (unsigned long)_etext;
 100         init_mm.end_data = (unsigned long)_edata;
 101         init_mm.brk = (unsigned long)_end;
 102
 103         /* first page of system - kernel .vector starts here */
 104         min_low_pfn = ARCH_PFN_OFFSET;
 105
 106         /* Last usable page of low mem */
 107         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 108
 109 #ifdef CONFIG_HIGHMEM
 110         min_high_pfn = PFN_DOWN(high_mem_start);
 111         max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 112 #endif
 113
 114         max_mapnr = max_pfn - min_low_pfn;
 115
 116         /*------------- bootmem allocator setup -----------------------*/
 117
 118         /*
 119          * seed the bootmem allocator after any DT memory node parsing or
 120          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 121          *
 122          * Only low mem is added, otherwise we have crashes when allocating
 123          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 124          * avail memory, ending in highmem with a > 32-bit address. However
 125          * it then tries to memset it with a truncaed 32-bit handle, causing
 126          * the crash
 127          */
 128
 129         memblock_add(low_mem_start, low_mem_sz);
 130         memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 131
 132 #ifdef CONFIG_BLK_DEV_INITRD
 133         if (initrd_start)
 134                 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 135 #endif
 136
 137         memblock_dump_all();
 138
 139         /*----------------- node/zones setup --------------------------*/
 140         memset(zones_size, 0, sizeof(zones_size));
 141         memset(zones_holes, 0, sizeof(zones_holes));
 142
 143         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 144         zones_holes[ZONE_NORMAL] = 0;
 145
 146 #ifdef CONFIG_HIGHMEM
 147         zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
 148
 149         /* This handles the peripheral address space hole */
 150         zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
 151 #endif
 152
 153         /*
 154          * We can't use the helper free_area_init(zones[]) because it uses
 155          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
 156          * when our kernel doesn't start at PAGE_OFFSET, i.e.
 157          * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
 158          */
 159         free_area_init_node(0,                  /* node-id */
 160                             zones_size,         /* num pages per zone */
 161                             min_low_pfn,        /* first pfn of node */
 162                             zones_holes);       /* holes */
 163
 164 #ifdef CONFIG_HIGHMEM
 165         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 166         kmap_init();
 167 #endif
 168 }
 169
 170 /*
 171  * mem_init - initializes memory
 172  *
 173  * Frees up bootmem
 174  * Calculates and displays memory available/used
 175  */
 176 void __init mem_init(void)
 177 {
 178 #ifdef CONFIG_HIGHMEM
 179         unsigned long tmp;
 180
 181         reset_all_zones_managed_pages();
 182         for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
 183                 free_highmem_page(pfn_to_page(tmp));
 184 #endif
 185
 186         free_all_bootmem();
 187         mem_init_print_info(NULL);
 188 }
 189
 190 /*
 191  * free_initmem: Free all the __init memory.
 192  */
 193 void __init_refok free_initmem(void)
 194 {
 195         free_initmem_default(-1);
 196 }
 197
 198 #ifdef CONFIG_BLK_DEV_INITRD
 199 void __init free_initrd_mem(unsigned long start, unsigned long end)
 200 {
 201         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 202 }
 203 #endif