kernel/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                 if (base != low_mem_start)
  55                         panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
  56
  57                 low_mem_sz = size;
  58                 in_use = 1;
  59         } else {
  60 #ifdef CONFIG_HIGHMEM
  61                 high_mem_start = base;
  62                 high_mem_sz = size;
  63                 in_use = 1;
  64 #endif
  65         }
  66
  67         pr_info("Memory @ %llx [%lldM] %s\n",
  68                 base, TO_MB(size), !in_use ? "Not used":"");
  69 }
  70
  71 #ifdef CONFIG_BLK_DEV_INITRD
  72 static int __init early_initrd(char *p)
  73 {
  74         unsigned long start, size;
  75         char *endp;
  76
  77         start = memparse(p, &endp);
  78         if (*endp == ',') {
  79                 size = memparse(endp + 1, NULL);
  80
  81                 initrd_start = (unsigned long)__va(start);
  82                 initrd_end = (unsigned long)__va(start + size);
  83         }
  84         return 0;
  85 }
  86 early_param("initrd", early_initrd);
  87 #endif
  88
  89 /*
  90  * First memory setup routine called from setup_arch()
  91  * 1. setup swapper's mm @init_mm
  92  * 2. Count the pages we have and setup bootmem allocator
  93  * 3. zone setup
  94  */
  95 void __init setup_arch_memory(void)
  96 {
  97         unsigned long zones_size[MAX_NR_ZONES];
  98         unsigned long zones_holes[MAX_NR_ZONES];
  99
 100         init_mm.start_code = (unsigned long)_text;
 101         init_mm.end_code = (unsigned long)_etext;
 102         init_mm.end_data = (unsigned long)_edata;
 103         init_mm.brk = (unsigned long)_end;
 104
 105         /* first page of system - kernel .vector starts here */
 106         min_low_pfn = ARCH_PFN_OFFSET;
 107
 108         /* Last usable page of low mem */
 109         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 110
 111 #ifdef CONFIG_HIGHMEM
 112         min_high_pfn = PFN_DOWN(high_mem_start);
 113         max_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 114 #endif
 115
 116         max_mapnr = max_pfn - min_low_pfn;
 117
 118         /*------------- bootmem allocator setup -----------------------*/
 119
 120         /*
 121          * seed the bootmem allocator after any DT memory node parsing or
 122          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 123          *
 124          * Only low mem is added, otherwise we have crashes when allocating
 125          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 126          * avail memory, ending in highmem with a > 32-bit address. However
 127          * it then tries to memset it with a truncaed 32-bit handle, causing
 128          * the crash
 129          */
 130
 131         memblock_add(low_mem_start, low_mem_sz);
 132         memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 133
 134 #ifdef CONFIG_BLK_DEV_INITRD
 135         if (initrd_start)
 136                 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 137 #endif
 138
 139         memblock_dump_all();
 140
 141         /*----------------- node/zones setup --------------------------*/
 142         memset(zones_size, 0, sizeof(zones_size));
 143         memset(zones_holes, 0, sizeof(zones_holes));
 144
 145         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 146         zones_holes[ZONE_NORMAL] = 0;
 147
 148 #ifdef CONFIG_HIGHMEM
 149         zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
 150
 151         /* This handles the peripheral address space hole */
 152         zones_holes[ZONE_HIGHMEM] = min_high_pfn - max_low_pfn;
 153 #endif
 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         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 168         kmap_init();
 169 #endif
 170 }
 171
 172 /*
 173  * mem_init - initializes memory
 174  *
 175  * Frees up bootmem
 176  * Calculates and displays memory available/used
 177  */
 178 void __init mem_init(void)
 179 {
 180 #ifdef CONFIG_HIGHMEM
 181         unsigned long tmp;
 182
 183         reset_all_zones_managed_pages();
 184         for (tmp = min_high_pfn; tmp < max_pfn; tmp++)
 185                 free_highmem_page(pfn_to_page(tmp));
 186 #endif
 187
 188         free_all_bootmem();
 189         mem_init_print_info(NULL);
 190 }
 191
 192 /*
 193  * free_initmem: Free all the __init memory.
 194  */
 195 void __init_refok free_initmem(void)
 196 {
 197         free_initmem_default(-1);
 198 }
 199
 200 #ifdef CONFIG_BLK_DEV_INITRD
 201 void __init free_initrd_mem(unsigned long start, unsigned long end)
 202 {
 203         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 204 }
 205 #endif