release/src-rt-6.x.4708/linux/linux-2.6.36/arch/microblaze/mm/init.c

   1 /*
   2  * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
   3  * Copyright (C) 2006 Atmark Techno, Inc.
   4  *
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License. See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9
  10 #include <linux/bootmem.h>
  11 #include <linux/init.h>
  12 #include <linux/kernel.h>
  13 #include <linux/memblock.h>
  14 #include <linux/mm.h> /* mem_init */
  15 #include <linux/initrd.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/pfn.h>
  18 #include <linux/slab.h>
  19 #include <linux/swap.h>
  20
  21 #include <asm/page.h>
  22 #include <asm/mmu_context.h>
  23 #include <asm/pgalloc.h>
  24 #include <asm/sections.h>
  25 #include <asm/tlb.h>
  26
  27 /* Use for MMU and noMMU because of PCI generic code */
  28 int mem_init_done;
  29
  30 #ifndef CONFIG_MMU
  31 unsigned int __page_offset;
  32 EXPORT_SYMBOL(__page_offset);
  33
  34 #else
  35 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  36
  37 static int init_bootmem_done;
  38 #endif /* CONFIG_MMU */
  39
  40 char *klimit = _end;
  41
  42 /*
  43  * Initialize the bootmem system and give it all the memory we
  44  * have available.
  45  */
  46 unsigned long memory_start;
  47 EXPORT_SYMBOL(memory_start);
  48 unsigned long memory_end; /* due to mm/nommu.c */
  49 unsigned long memory_size;
  50 EXPORT_SYMBOL(memory_size);
  51
  52 /*
  53  * paging_init() sets up the page tables - in fact we've already done this.
  54  */
  55 static void __init paging_init(void)
  56 {
  57         unsigned long zones_size[MAX_NR_ZONES];
  58
  59         /* Clean every zones */
  60         memset(zones_size, 0, sizeof(zones_size));
  61
  62         /*
  63          * old: we can DMA to/from any address.put all page into ZONE_DMA
  64          * We use only ZONE_NORMAL
  65          */
  66         zones_size[ZONE_NORMAL] = max_mapnr;
  67
  68         free_area_init(zones_size);
  69 }
  70
  71 void __init setup_memory(void)
  72 {
  73         int i;
  74         unsigned long map_size;
  75 #ifndef CONFIG_MMU
  76         u32 kernel_align_start, kernel_align_size;
  77
  78         /* Find main memory where is the kernel */
  79         for (i = 0; i < memblock.memory.cnt; i++) {
  80                 memory_start = (u32) memblock.memory.region[i].base;
  81                 memory_end = (u32) memblock.memory.region[i].base
  82                                 + (u32) memblock.memory.region[i].size;
  83                 if ((memory_start <= (u32)_text) &&
  84                                         ((u32)_text <= memory_end)) {
  85                         memory_size = memory_end - memory_start;
  86                         PAGE_OFFSET = memory_start;
  87                         printk(KERN_INFO "%s: Main mem: 0x%x-0x%x, "
  88                                 "size 0x%08x\n", __func__, (u32) memory_start,
  89                                         (u32) memory_end, (u32) memory_size);
  90                         break;
  91                 }
  92         }
  93
  94         if (!memory_start || !memory_end) {
  95                 panic("%s: Missing memory setting 0x%08x-0x%08x\n",
  96                         __func__, (u32) memory_start, (u32) memory_end);
  97         }
  98
  99         /* reservation of region where is the kernel */
 100         kernel_align_start = PAGE_DOWN((u32)_text);
 101         /* ALIGN can be remove because _end in vmlinux.lds.S is align */
 102         kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
 103         memblock_reserve(kernel_align_start, kernel_align_size);
 104         printk(KERN_INFO "%s: kernel addr=0x%08x-0x%08x size=0x%08x\n",
 105                 __func__, kernel_align_start, kernel_align_start
 106                         + kernel_align_size, kernel_align_size);
 107
 108 #endif
 109         /*
 110          * Kernel:
 111          * start: base phys address of kernel - page align
 112          * end: base phys address of kernel - page align
 113          *
 114          * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 115          * max_low_pfn
 116          * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 117          * num_physpages - number of all pages
 118          */
 119
 120         /* memory start is from the kernel end (aligned) to higher addr */
 121         min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 122         /* RAM is assumed contiguous */
 123         num_physpages = max_mapnr = memory_size >> PAGE_SHIFT;
 124         max_pfn = max_low_pfn = memory_end >> PAGE_SHIFT;
 125
 126         printk(KERN_INFO "%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 127         printk(KERN_INFO "%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 128         printk(KERN_INFO "%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 129
 130         /*
 131          * Find an area to use for the bootmem bitmap.
 132          * We look for the first area which is at least
 133          * 128kB in length (128kB is enough for a bitmap
 134          * for 4GB of memory, using 4kB pages), plus 1 page
 135          * (in case the address isn't page-aligned).
 136          */
 137         map_size = init_bootmem_node(NODE_DATA(0),
 138                 PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn);
 139         memblock_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size);
 140
 141         /* free bootmem is whole main memory */
 142         free_bootmem(memory_start, memory_size);
 143
 144         /* reserve allocate blocks */
 145         for (i = 0; i < memblock.reserved.cnt; i++) {
 146                 pr_debug("reserved %d - 0x%08x-0x%08x\n", i,
 147                         (u32) memblock.reserved.region[i].base,
 148                         (u32) memblock_size_bytes(&memblock.reserved, i));
 149                 reserve_bootmem(memblock.reserved.region[i].base,
 150                         memblock_size_bytes(&memblock.reserved, i) - 1, BOOTMEM_DEFAULT);
 151         }
 152 #ifdef CONFIG_MMU
 153         init_bootmem_done = 1;
 154 #endif
 155         paging_init();
 156 }
 157
 158 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 159 {
 160         unsigned long addr;
 161
 162         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 163                 ClearPageReserved(virt_to_page(addr));
 164                 init_page_count(virt_to_page(addr));
 165                 free_page(addr);
 166                 totalram_pages++;
 167         }
 168         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 169 }
 170
 171 #ifdef CONFIG_BLK_DEV_INITRD
 172 void free_initrd_mem(unsigned long start, unsigned long end)
 173 {
 174         int pages = 0;
 175         for (; start < end; start += PAGE_SIZE) {
 176                 ClearPageReserved(virt_to_page(start));
 177                 init_page_count(virt_to_page(start));
 178                 free_page(start);
 179                 totalram_pages++;
 180                 pages++;
 181         }
 182         printk(KERN_NOTICE "Freeing initrd memory: %dk freed\n",
 183                                         (int)(pages * (PAGE_SIZE / 1024)));
 184 }
 185 #endif
 186
 187 void free_initmem(void)
 188 {
 189         free_init_pages("unused kernel memory",
 190                         (unsigned long)(&__init_begin),
 191                         (unsigned long)(&__init_end));
 192 }
 193
 194 void __init mem_init(void)
 195 {
 196         high_memory = (void *)__va(memory_end);
 197         /* this will put all memory onto the freelists */
 198         totalram_pages += free_all_bootmem();
 199
 200         printk(KERN_INFO "Memory: %luk/%luk available\n",
 201                nr_free_pages() << (PAGE_SHIFT-10),
 202                num_physpages << (PAGE_SHIFT-10));
 203         mem_init_done = 1;
 204 }
 205
 206 #ifndef CONFIG_MMU
 207 int page_is_ram(unsigned long pfn)
 208 {
 209         return __range_ok(pfn, 0);
 210 }
 211 #else
 212 int page_is_ram(unsigned long pfn)
 213 {
 214         return pfn < max_low_pfn;
 215 }
 216
 217 /*
 218  * Check for command-line options that affect what MMU_init will do.
 219  */
 220 static void mm_cmdline_setup(void)
 221 {
 222         unsigned long maxmem = 0;
 223         char *p = cmd_line;
 224
 225         /* Look for mem= option on command line */
 226         p = strstr(cmd_line, "mem=");
 227         if (p) {
 228                 p += 4;
 229                 maxmem = memparse(p, &p);
 230                 if (maxmem && memory_size > maxmem) {
 231                         memory_size = maxmem;
 232                         memory_end = memory_start + memory_size;
 233                         memblock.memory.region[0].size = memory_size;
 234                 }
 235         }
 236 }
 237
 238 /*
 239  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 240  */
 241 static void __init mmu_init_hw(void)
 242 {
 243         /*
 244          * The Zone Protection Register (ZPR) defines how protection will
 245          * be applied to every page which is a member of a given zone. At
 246          * present, we utilize only two of the zones.
 247          * The zone index bits (of ZSEL) in the PTE are used for software
 248          * indicators, except the LSB.  For user access, zone 1 is used,
 249          * for kernel access, zone 0 is used.  We set all but zone 1
 250          * to zero, allowing only kernel access as indicated in the PTE.
 251          * For zone 1, we set a 01 binary (a value of 10 will not work)
 252          * to allow user access as indicated in the PTE.  This also allows
 253          * kernel access as indicated in the PTE.
 254          */
 255         __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
 256                         "mts rzpr, r11;"
 257                         : : : "r11");
 258 }
 259
 260 /*
 261  * MMU_init sets up the basic memory mappings for the kernel,
 262  * including both RAM and possibly some I/O regions,
 263  * and sets up the page tables and the MMU hardware ready to go.
 264  */
 265
 266 /* called from head.S */
 267 asmlinkage void __init mmu_init(void)
 268 {
 269         unsigned int kstart, ksize;
 270
 271         if (!memblock.reserved.cnt) {
 272                 printk(KERN_EMERG "Error memory count\n");
 273                 machine_restart(NULL);
 274         }
 275
 276         if ((u32) memblock.memory.region[0].size < 0x1000000) {
 277                 printk(KERN_EMERG "Memory must be greater than 16MB\n");
 278                 machine_restart(NULL);
 279         }
 280         /* Find main memory where the kernel is */
 281         memory_start = (u32) memblock.memory.region[0].base;
 282         memory_end = (u32) memblock.memory.region[0].base +
 283                                 (u32) memblock.memory.region[0].size;
 284         memory_size = memory_end - memory_start;
 285
 286         mm_cmdline_setup();
 287
 288         /*
 289          * Map out the kernel text/data/bss from the available physical
 290          * memory.
 291          */
 292         kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 293         /* kernel size */
 294         ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 295         memblock_reserve(kstart, ksize);
 296
 297 #if defined(CONFIG_BLK_DEV_INITRD)
 298         /* Remove the init RAM disk from the available memory. */
 299 /*      if (initrd_start) {
 300                 mem_pieces_remove(&phys_avail, __pa(initrd_start),
 301                                   initrd_end - initrd_start, 1);
 302         }*/
 303 #endif /* CONFIG_BLK_DEV_INITRD */
 304
 305         /* Initialize the MMU hardware */
 306         mmu_init_hw();
 307
 308         /* Map in all of RAM starting at CONFIG_KERNEL_START */
 309         mapin_ram();
 310
 311 #ifdef HIGHMEM_START_BOOL
 312         ioremap_base = HIGHMEM_START;
 313 #else
 314         ioremap_base = 0xfe000000UL;    /* for now, could be 0xfffff000 */
 315 #endif /* CONFIG_HIGHMEM */
 316         ioremap_bot = ioremap_base;
 317
 318         /* Initialize the context management stuff */
 319         mmu_context_init();
 320 }
 321
 322 /* This is only called until mem_init is done. */
 323 void __init *early_get_page(void)
 324 {
 325         void *p;
 326         if (init_bootmem_done) {
 327                 p = alloc_bootmem_pages(PAGE_SIZE);
 328         } else {
 329                 /*
 330                  * Mem start + 32MB -> here is limit
 331                  * because of mem mapping from head.S
 332                  */
 333                 p = __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
 334                                         memory_start + 0x2000000));
 335         }
 336         return p;
 337 }
 338
 339 #endif /* CONFIG_MMU */
 340
 341 void * __init_refok alloc_maybe_bootmem(size_t size, gfp_t mask)
 342 {
 343         if (mem_init_done)
 344                 return kmalloc(size, mask);
 345         else
 346                 return alloc_bootmem(size);
 347 }
 348
 349 void * __init_refok zalloc_maybe_bootmem(size_t size, gfp_t mask)
 350 {
 351         void *p;
 352
 353         if (mem_init_done)
 354                 p = kzalloc(size, mask);
 355         else {
 356                 p = alloc_bootmem(size);
 357                 if (p)
 358                         memset(p, 0, size);
 359         }
 360         return p;
 361 }