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 long __init arc_get_mem_sz(void)
  44 {
  45         return low_mem_sz;
  46 }
  47
  48 /* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
  49 static int __init setup_mem_sz(char *str)
  50 {
  51         low_mem_sz = memparse(str, NULL) & PAGE_MASK;
  52
  53         /* early console might not be setup yet - it will show up later */
  54         pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(low_mem_sz));
  55
  56         return 0;
  57 }
  58 early_param("mem", setup_mem_sz);
  59
  60 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
  61 {
  62         int in_use = 0;
  63
  64         if (!low_mem_sz) {
  65                 if (base != low_mem_start)
  66                         panic("CONFIG_LINUX_LINK_BASE != DT memory { }");
  67
  68                 low_mem_sz = size;
  69                 in_use = 1;
  70         } else {
  71 #ifdef CONFIG_HIGHMEM
  72                 high_mem_start = base;
  73                 high_mem_sz = size;
  74                 in_use = 1;
  75 #endif
  76         }
  77
  78         pr_info("Memory @ %llx [%lldM] %s\n",
  79                 base, TO_MB(size), !in_use ? "Not used":"");
  80 }
  81
  82 #ifdef CONFIG_BLK_DEV_INITRD
  83 static int __init early_initrd(char *p)
  84 {
  85         unsigned long start, size;
  86         char *endp;
  87
  88         start = memparse(p, &endp);
  89         if (*endp == ',') {
  90                 size = memparse(endp + 1, NULL);
  91
  92                 initrd_start = (unsigned long)__va(start);
  93                 initrd_end = (unsigned long)__va(start + size);
  94         }
  95         return 0;
  96 }
  97 early_param("initrd", early_initrd);
  98 #endif
  99
 100 /*
 101  * First memory setup routine called from setup_arch()
 102  * 1. setup swapper's mm @init_mm
 103  * 2. Count the pages we have and setup bootmem allocator
 104  * 3. zone setup
 105  */
 106 void __init setup_arch_memory(void)
 107 {
 108         unsigned long zones_size[MAX_NR_ZONES];
 109         unsigned long zones_holes[MAX_NR_ZONES];
 110
 111         init_mm.start_code = (unsigned long)_text;
 112         init_mm.end_code = (unsigned long)_etext;
 113         init_mm.end_data = (unsigned long)_edata;
 114         init_mm.brk = (unsigned long)_end;
 115
 116         /* first page of system - kernel .vector starts here */
 117         min_low_pfn = ARCH_PFN_OFFSET;
 118
 119         /* Last usable page of low mem */
 120         max_low_pfn = max_pfn = PFN_DOWN(low_mem_start + low_mem_sz);
 121
 122 #ifdef CONFIG_FLATMEM
 123         /* pfn_valid() uses this */
 124         max_mapnr = max_low_pfn - min_low_pfn;
 125 #endif
 126
 127         /*------------- bootmem allocator setup -----------------------*/
 128
 129         /*
 130          * seed the bootmem allocator after any DT memory node parsing or
 131          * "mem=xxx" cmdline overrides have potentially updated @arc_mem_sz
 132          *
 133          * Only low mem is added, otherwise we have crashes when allocating
 134          * mem_map[] itself. NO_BOOTMEM allocates mem_map[] at the end of
 135          * avail memory, ending in highmem with a > 32-bit address. However
 136          * it then tries to memset it with a truncaed 32-bit handle, causing
 137          * the crash
 138          */
 139
 140         memblock_add_node(low_mem_start, low_mem_sz, 0);
 141         memblock_reserve(low_mem_start, __pa(_end) - low_mem_start);
 142
 143 #ifdef CONFIG_BLK_DEV_INITRD
 144         if (initrd_start)
 145                 memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
 146 #endif
 147
 148         early_init_fdt_reserve_self();
 149         early_init_fdt_scan_reserved_mem();
 150
 151         memblock_dump_all();
 152
 153         /*----------------- node/zones setup --------------------------*/
 154         memset(zones_size, 0, sizeof(zones_size));
 155         memset(zones_holes, 0, sizeof(zones_holes));
 156
 157         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 158         zones_holes[ZONE_NORMAL] = 0;
 159
 160         /*
 161          * We can't use the helper free_area_init(zones[]) because it uses
 162          * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
 163          * when our kernel doesn't start at PAGE_OFFSET, i.e.
 164          * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
 165          */
 166         free_area_init_node(0,                  /* node-id */
 167                             zones_size,         /* num pages per zone */
 168                             min_low_pfn,        /* first pfn of node */
 169                             zones_holes);       /* holes */
 170
 171 #ifdef CONFIG_HIGHMEM
 172         /*
 173          * Populate a new node with highmem
 174          *
 175          * On ARC (w/o PAE) HIGHMEM addresses are actually smaller (0 based)
 176          * than addresses in normal ala low memory (0x8000_0000 based).
 177          * Even with PAE, the huge peripheral space hole would waste a lot of
 178          * mem with single mem_map[]. This warrants a mem_map per region design.
 179          * Thus HIGHMEM on ARC is imlemented with DISCONTIGMEM.
 180          *
 181          * DISCONTIGMEM in turns requires multiple nodes. node 0 above is
 182          * populated with normal memory zone while node 1 only has highmem
 183          */
 184         node_set_online(1);
 185
 186         min_high_pfn = PFN_DOWN(high_mem_start);
 187         max_high_pfn = PFN_DOWN(high_mem_start + high_mem_sz);
 188
 189         zones_size[ZONE_NORMAL] = 0;
 190         zones_holes[ZONE_NORMAL] = 0;
 191
 192         zones_size[ZONE_HIGHMEM] = max_high_pfn - min_high_pfn;
 193         zones_holes[ZONE_HIGHMEM] = 0;
 194
 195         free_area_init_node(1,                  /* node-id */
 196                             zones_size,         /* num pages per zone */
 197                             min_high_pfn,       /* first pfn of node */
 198                             zones_holes);       /* holes */
 199
 200         high_memory = (void *)(min_high_pfn << PAGE_SHIFT);
 201         kmap_init();
 202 #endif
 203 }
 204
 205 /*
 206  * mem_init - initializes memory
 207  *
 208  * Frees up bootmem
 209  * Calculates and displays memory available/used
 210  */
 211 void __init mem_init(void)
 212 {
 213 #ifdef CONFIG_HIGHMEM
 214         unsigned long tmp;
 215
 216         reset_all_zones_managed_pages();
 217         for (tmp = min_high_pfn; tmp < max_high_pfn; tmp++)
 218                 free_highmem_page(pfn_to_page(tmp));
 219 #endif
 220
 221         free_all_bootmem();
 222         mem_init_print_info(NULL);
 223 }
 224
 225 /*
 226  * free_initmem: Free all the __init memory.
 227  */
 228 void __ref free_initmem(void)
 229 {
 230         free_initmem_default(-1);
 231 }
 232
 233 #ifdef CONFIG_BLK_DEV_INITRD
 234 void __init free_initrd_mem(unsigned long start, unsigned long end)
 235 {
 236         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 237 }
 238 #endif