arch/xtensa/mm/init.c

   1 /*
   2  * arch/xtensa/mm/init.c
   3  *
   4  * Derived from MIPS, PPC.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  *
  10  * Copyright (C) 2001 - 2005 Tensilica Inc.
  11  *
  12  * Chris Zankel <chris@zankel.net>
  13  * Joe Taylor   <joe@tensilica.com, joetylr@yahoo.com>
  14  * Marc Gauthier
  15  * Kevin Chea
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/errno.h>
  20 #include <linux/bootmem.h>
  21 #include <linux/gfp.h>
  22 #include <linux/swap.h>
  23 #include <linux/mman.h>
  24 #include <linux/nodemask.h>
  25 #include <linux/mm.h>
  26
  27 #include <asm/bootparam.h>
  28 #include <asm/page.h>
  29
  30 /* References to section boundaries */
  31
  32 extern char _ftext, _etext, _fdata, _edata, _rodata_end;
  33 extern char __init_begin, __init_end;
  34
  35 /*
  36  * mem_reserve(start, end, must_exist)
  37  *
  38  * Reserve some memory from the memory pool.
  39  *
  40  * Parameters:
  41  *  start       Start of region,
  42  *  end         End of region,
  43  *  must_exist  Must exist in memory pool.
  44  *
  45  * Returns:
  46  *  0 (memory area couldn't be mapped)
  47  * -1 (success)
  48  */
  49
  50 int __init mem_reserve(unsigned long start, unsigned long end, int must_exist)
  51 {
  52         int i;
  53
  54         if (start == end)
  55                 return 0;
  56
  57         start = start & PAGE_MASK;
  58         end = PAGE_ALIGN(end);
  59
  60         for (i = 0; i < sysmem.nr_banks; i++)
  61                 if (start < sysmem.bank[i].end
  62                     && end >= sysmem.bank[i].start)
  63                         break;
  64
  65         if (i == sysmem.nr_banks) {
  66                 if (must_exist)
  67                         printk (KERN_WARNING "mem_reserve: [0x%0lx, 0x%0lx) "
  68                                 "not in any region!\n", start, end);
  69                 return 0;
  70         }
  71
  72         if (start > sysmem.bank[i].start) {
  73                 if (end < sysmem.bank[i].end) {
  74                         /* split entry */
  75                         if (sysmem.nr_banks >= SYSMEM_BANKS_MAX)
  76                                 panic("meminfo overflow\n");
  77                         sysmem.bank[sysmem.nr_banks].start = end;
  78                         sysmem.bank[sysmem.nr_banks].end = sysmem.bank[i].end;
  79                         sysmem.nr_banks++;
  80                 }
  81                 sysmem.bank[i].end = start;
  82         } else {
  83                 if (end < sysmem.bank[i].end)
  84                         sysmem.bank[i].start = end;
  85                 else {
  86                         /* remove entry */
  87                         sysmem.nr_banks--;
  88                         sysmem.bank[i].start = sysmem.bank[sysmem.nr_banks].start;
  89                         sysmem.bank[i].end   = sysmem.bank[sysmem.nr_banks].end;
  90                 }
  91         }
  92         return -1;
  93 }
  94
  95
  96 /*
  97  * Initialize the bootmem system and give it all the memory we have available.
  98  */
  99
 100 void __init bootmem_init(void)
 101 {
 102         unsigned long pfn;
 103         unsigned long bootmap_start, bootmap_size;
 104         int i;
 105
 106         max_low_pfn = max_pfn = 0;
 107         min_low_pfn = ~0;
 108
 109         for (i=0; i < sysmem.nr_banks; i++) {
 110                 pfn = PAGE_ALIGN(sysmem.bank[i].start) >> PAGE_SHIFT;
 111                 if (pfn < min_low_pfn)
 112                         min_low_pfn = pfn;
 113                 pfn = PAGE_ALIGN(sysmem.bank[i].end - 1) >> PAGE_SHIFT;
 114                 if (pfn > max_pfn)
 115                         max_pfn = pfn;
 116         }
 117
 118         if (min_low_pfn > max_pfn)
 119                 panic("No memory found!\n");
 120
 121         max_low_pfn = max_pfn < MAX_MEM_PFN >> PAGE_SHIFT ?
 122                 max_pfn : MAX_MEM_PFN >> PAGE_SHIFT;
 123
 124         /* Find an area to use for the bootmem bitmap. */
 125
 126         bootmap_size = bootmem_bootmap_pages(max_low_pfn - min_low_pfn);
 127         bootmap_size <<= PAGE_SHIFT;
 128         bootmap_start = ~0;
 129
 130         for (i=0; i<sysmem.nr_banks; i++)
 131                 if (sysmem.bank[i].end - sysmem.bank[i].start >= bootmap_size) {
 132                         bootmap_start = sysmem.bank[i].start;
 133                         break;
 134                 }
 135
 136         if (bootmap_start == ~0UL)
 137                 panic("Cannot find %ld bytes for bootmap\n", bootmap_size);
 138
 139         /* Reserve the bootmem bitmap area */
 140
 141         mem_reserve(bootmap_start, bootmap_start + bootmap_size, 1);
 142         bootmap_size = init_bootmem_node(NODE_DATA(0),
 143                                          bootmap_start >> PAGE_SHIFT,
 144                                          min_low_pfn,
 145                                          max_low_pfn);
 146
 147         /* Add all remaining memory pieces into the bootmem map */
 148
 149         for (i=0; i<sysmem.nr_banks; i++)
 150                 free_bootmem(sysmem.bank[i].start,
 151                              sysmem.bank[i].end - sysmem.bank[i].start);
 152
 153 }
 154
 155
 156 void __init zones_init(void)
 157 {
 158         unsigned long zones_size[MAX_NR_ZONES];
 159         int i;
 160
 161         /* All pages are DMA-able, so we put them all in the DMA zone. */
 162
 163         zones_size[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET;
 164         for (i = 1; i < MAX_NR_ZONES; i++)
 165                 zones_size[i] = 0;
 166
 167 #ifdef CONFIG_HIGHMEM
 168         zones_size[ZONE_HIGHMEM] = max_pfn - max_low_pfn;
 169 #endif
 170
 171         free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL);
 172 }
 173
 174 /*
 175  * Initialize memory pages.
 176  */
 177
 178 void __init mem_init(void)
 179 {
 180         unsigned long codesize, reservedpages, datasize, initsize;
 181         unsigned long highmemsize, tmp, ram;
 182
 183         max_mapnr = num_physpages = max_low_pfn - ARCH_PFN_OFFSET;
 184         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 185         highmemsize = 0;
 186
 187 #ifdef CONFIG_HIGHMEM
 188 #error HIGHGMEM not implemented in init.c
 189 #endif
 190
 191         totalram_pages += free_all_bootmem();
 192
 193         reservedpages = ram = 0;
 194         for (tmp = 0; tmp < max_mapnr; tmp++) {
 195                 ram++;
 196                 if (PageReserved(mem_map+tmp))
 197                         reservedpages++;
 198         }
 199
 200         codesize =  (unsigned long) &_etext - (unsigned long) &_ftext;
 201         datasize =  (unsigned long) &_edata - (unsigned long) &_fdata;
 202         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 203
 204         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, "
 205                "%ldk data, %ldk init %ldk highmem)\n",
 206                nr_free_pages() << (PAGE_SHIFT-10),
 207                ram << (PAGE_SHIFT-10),
 208                codesize >> 10,
 209                reservedpages << (PAGE_SHIFT-10),
 210                datasize >> 10,
 211                initsize >> 10,
 212                highmemsize >> 10);
 213 }
 214
 215 void
 216 free_reserved_mem(void *start, void *end)
 217 {
 218         for (; start < end; start += PAGE_SIZE) {
 219                 ClearPageReserved(virt_to_page(start));
 220                 init_page_count(virt_to_page(start));
 221                 free_page((unsigned long)start);
 222                 totalram_pages++;
 223         }
 224 }
 225
 226 #ifdef CONFIG_BLK_DEV_INITRD
 227 extern int initrd_is_mapped;
 228
 229 void free_initrd_mem(unsigned long start, unsigned long end)
 230 {
 231         if (initrd_is_mapped) {
 232                 free_reserved_mem((void*)start, (void*)end);
 233                 printk ("Freeing initrd memory: %ldk freed\n",(end-start)>>10);
 234         }
 235 }
 236 #endif
 237
 238 void free_initmem(void)
 239 {
 240         free_reserved_mem(&__init_begin, &__init_end);
 241         printk("Freeing unused kernel memory: %dk freed\n",
 242                (&__init_end - &__init_begin) >> 10);
 243 }