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 #include <linux/export.h>
  21
  22 #include <asm/page.h>
  23 #include <asm/mmu_context.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/sections.h>
  26 #include <asm/tlb.h>
  27 #include <asm/fixmap.h>
  28
  29 /* Use for MMU and noMMU because of PCI generic code */
  30 int mem_init_done;
  31
  32 #ifndef CONFIG_MMU
  33 unsigned int __page_offset;
  34 EXPORT_SYMBOL(__page_offset);
  35
  36 #else
  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_size;
  49 EXPORT_SYMBOL(memory_size);
  50 unsigned long lowmem_size;
  51
  52 #ifdef CONFIG_HIGHMEM
  53 pte_t *kmap_pte;
  54 EXPORT_SYMBOL(kmap_pte);
  55 pgprot_t kmap_prot;
  56 EXPORT_SYMBOL(kmap_prot);
  57
  58 static inline pte_t *virt_to_kpte(unsigned long vaddr)
  59 {
  60         return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
  61                         vaddr), vaddr);
  62 }
  63
  64 static void __init highmem_init(void)
  65 {
  66         pr_debug("%x\n", (u32)PKMAP_BASE);
  67         map_page(PKMAP_BASE, 0, 0);     /* XXX gross */
  68         pkmap_page_table = virt_to_kpte(PKMAP_BASE);
  69
  70         kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
  71         kmap_prot = PAGE_KERNEL;
  72 }
  73
  74 static void highmem_setup(void)
  75 {
  76         unsigned long pfn;
  77
  78         for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
  79                 struct page *page = pfn_to_page(pfn);
  80
  81                 /* FIXME not sure about */
  82                 if (!memblock_is_reserved(pfn << PAGE_SHIFT))
  83                         free_highmem_page(page);
  84         }
  85 }
  86 #endif /* CONFIG_HIGHMEM */
  87
  88 /*
  89  * paging_init() sets up the page tables - in fact we've already done this.
  90  */
  91 static void __init paging_init(void)
  92 {
  93         unsigned long zones_size[MAX_NR_ZONES];
  94 #ifdef CONFIG_MMU
  95         int idx;
  96
  97         /* Setup fixmaps */
  98         for (idx = 0; idx < __end_of_fixed_addresses; idx++)
  99                 clear_fixmap(idx);
 100 #endif
 101
 102         /* Clean every zones */
 103         memset(zones_size, 0, sizeof(zones_size));
 104
 105 #ifdef CONFIG_HIGHMEM
 106         highmem_init();
 107
 108         zones_size[ZONE_DMA] = max_low_pfn;
 109         zones_size[ZONE_HIGHMEM] = max_pfn;
 110 #else
 111         zones_size[ZONE_DMA] = max_pfn;
 112 #endif
 113
 114         /* We don't have holes in memory map */
 115         free_area_init_nodes(zones_size);
 116 }
 117
 118 void __init setup_memory(void)
 119 {
 120         unsigned long map_size;
 121         struct memblock_region *reg;
 122
 123 #ifndef CONFIG_MMU
 124         u32 kernel_align_start, kernel_align_size;
 125
 126         /* Find main memory where is the kernel */
 127         for_each_memblock(memory, reg) {
 128                 memory_start = (u32)reg->base;
 129                 lowmem_size = reg->size;
 130                 if ((memory_start <= (u32)_text) &&
 131                         ((u32)_text <= (memory_start + lowmem_size - 1))) {
 132                         memory_size = lowmem_size;
 133                         PAGE_OFFSET = memory_start;
 134                         pr_info("%s: Main mem: 0x%x, size 0x%08x\n",
 135                                 __func__, (u32) memory_start,
 136                                         (u32) memory_size);
 137                         break;
 138                 }
 139         }
 140
 141         if (!memory_start || !memory_size) {
 142                 panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
 143                         __func__, (u32) memory_start, (u32) memory_size);
 144         }
 145
 146         /* reservation of region where is the kernel */
 147         kernel_align_start = PAGE_DOWN((u32)_text);
 148         /* ALIGN can be remove because _end in vmlinux.lds.S is align */
 149         kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
 150         pr_info("%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
 151                 __func__, kernel_align_start, kernel_align_start
 152                         + kernel_align_size, kernel_align_size);
 153         memblock_reserve(kernel_align_start, kernel_align_size);
 154 #endif
 155         /*
 156          * Kernel:
 157          * start: base phys address of kernel - page align
 158          * end: base phys address of kernel - page align
 159          *
 160          * min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
 161          * max_low_pfn
 162          * max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
 163          */
 164
 165         /* memory start is from the kernel end (aligned) to higher addr */
 166         min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
 167         /* RAM is assumed contiguous */
 168         max_mapnr = memory_size >> PAGE_SHIFT;
 169         max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
 170         max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
 171
 172         pr_info("%s: max_mapnr: %#lx\n", __func__, max_mapnr);
 173         pr_info("%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
 174         pr_info("%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
 175         pr_info("%s: max_pfn: %#lx\n", __func__, max_pfn);
 176
 177         /*
 178          * Find an area to use for the bootmem bitmap.
 179          * We look for the first area which is at least
 180          * 128kB in length (128kB is enough for a bitmap
 181          * for 4GB of memory, using 4kB pages), plus 1 page
 182          * (in case the address isn't page-aligned).
 183          */
 184         map_size = init_bootmem_node(NODE_DATA(0),
 185                 PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn);
 186         memblock_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size);
 187
 188         /* Add active regions with valid PFNs */
 189         for_each_memblock(memory, reg) {
 190                 unsigned long start_pfn, end_pfn;
 191
 192                 start_pfn = memblock_region_memory_base_pfn(reg);
 193                 end_pfn = memblock_region_memory_end_pfn(reg);
 194                 memblock_set_node(start_pfn << PAGE_SHIFT,
 195                                   (end_pfn - start_pfn) << PAGE_SHIFT,
 196                                   &memblock.memory, 0);
 197         }
 198
 199         /* free bootmem is whole main memory */
 200         free_bootmem_with_active_regions(0, max_low_pfn);
 201
 202         /* reserve allocate blocks */
 203         for_each_memblock(reserved, reg) {
 204                 unsigned long top = reg->base + reg->size - 1;
 205
 206                 pr_debug("reserved - 0x%08x-0x%08x, %lx, %lx\n",
 207                          (u32) reg->base, (u32) reg->size, top,
 208                                                 memory_start + lowmem_size - 1);
 209
 210                 if (top <= (memory_start + lowmem_size - 1)) {
 211                         reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
 212                 } else if (reg->base < (memory_start + lowmem_size - 1)) {
 213                         unsigned long trunc_size = memory_start + lowmem_size -
 214                                                                 reg->base;
 215                         reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
 216                 }
 217         }
 218
 219         /* XXX need to clip this if using highmem? */
 220         sparse_memory_present_with_active_regions(0);
 221
 222 #ifdef CONFIG_MMU
 223         init_bootmem_done = 1;
 224 #endif
 225         paging_init();
 226 }
 227
 228 #ifdef CONFIG_BLK_DEV_INITRD
 229 void free_initrd_mem(unsigned long start, unsigned long end)
 230 {
 231         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 232 }
 233 #endif
 234
 235 void free_initmem(void)
 236 {
 237         free_initmem_default(-1);
 238 }
 239
 240 void __init mem_init(void)
 241 {
 242         high_memory = (void *)__va(memory_start + lowmem_size - 1);
 243
 244         /* this will put all memory onto the freelists */
 245         free_all_bootmem();
 246 #ifdef CONFIG_HIGHMEM
 247         highmem_setup();
 248 #endif
 249
 250         mem_init_print_info(NULL);
 251 #ifdef CONFIG_MMU
 252         pr_info("Kernel virtual memory layout:\n");
 253         pr_info("  * 0x%08lx..0x%08lx  : fixmap\n", FIXADDR_START, FIXADDR_TOP);
 254 #ifdef CONFIG_HIGHMEM
 255         pr_info("  * 0x%08lx..0x%08lx  : highmem PTEs\n",
 256                 PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
 257 #endif /* CONFIG_HIGHMEM */
 258         pr_info("  * 0x%08lx..0x%08lx  : early ioremap\n",
 259                 ioremap_bot, ioremap_base);
 260         pr_info("  * 0x%08lx..0x%08lx  : vmalloc & ioremap\n",
 261                 (unsigned long)VMALLOC_START, VMALLOC_END);
 262 #endif
 263         mem_init_done = 1;
 264 }
 265
 266 #ifndef CONFIG_MMU
 267 int page_is_ram(unsigned long pfn)
 268 {
 269         return __range_ok(pfn, 0);
 270 }
 271 #else
 272 int page_is_ram(unsigned long pfn)
 273 {
 274         return pfn < max_low_pfn;
 275 }
 276
 277 /*
 278  * Check for command-line options that affect what MMU_init will do.
 279  */
 280 static void mm_cmdline_setup(void)
 281 {
 282         unsigned long maxmem = 0;
 283         char *p = cmd_line;
 284
 285         /* Look for mem= option on command line */
 286         p = strstr(cmd_line, "mem=");
 287         if (p) {
 288                 p += 4;
 289                 maxmem = memparse(p, &p);
 290                 if (maxmem && memory_size > maxmem) {
 291                         memory_size = maxmem;
 292                         memblock.memory.regions[0].size = memory_size;
 293                 }
 294         }
 295 }
 296
 297 /*
 298  * MMU_init_hw does the chip-specific initialization of the MMU hardware.
 299  */
 300 static void __init mmu_init_hw(void)
 301 {
 302         /*
 303          * The Zone Protection Register (ZPR) defines how protection will
 304          * be applied to every page which is a member of a given zone. At
 305          * present, we utilize only two of the zones.
 306          * The zone index bits (of ZSEL) in the PTE are used for software
 307          * indicators, except the LSB.  For user access, zone 1 is used,
 308          * for kernel access, zone 0 is used.  We set all but zone 1
 309          * to zero, allowing only kernel access as indicated in the PTE.
 310          * For zone 1, we set a 01 binary (a value of 10 will not work)
 311          * to allow user access as indicated in the PTE.  This also allows
 312          * kernel access as indicated in the PTE.
 313          */
 314         __asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
 315                         "mts rzpr, r11;"
 316                         : : : "r11");
 317 }
 318
 319 /*
 320  * MMU_init sets up the basic memory mappings for the kernel,
 321  * including both RAM and possibly some I/O regions,
 322  * and sets up the page tables and the MMU hardware ready to go.
 323  */
 324
 325 /* called from head.S */
 326 asmlinkage void __init mmu_init(void)
 327 {
 328         unsigned int kstart, ksize;
 329
 330         if (!memblock.reserved.cnt) {
 331                 pr_emerg("Error memory count\n");
 332                 machine_restart(NULL);
 333         }
 334
 335         if ((u32) memblock.memory.regions[0].size < 0x400000) {
 336                 pr_emerg("Memory must be greater than 4MB\n");
 337                 machine_restart(NULL);
 338         }
 339
 340         if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
 341                 pr_emerg("Kernel size is greater than memory node\n");
 342                 machine_restart(NULL);
 343         }
 344
 345         /* Find main memory where the kernel is */
 346         memory_start = (u32) memblock.memory.regions[0].base;
 347         lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
 348
 349         if (lowmem_size > CONFIG_LOWMEM_SIZE) {
 350                 lowmem_size = CONFIG_LOWMEM_SIZE;
 351 #ifndef CONFIG_HIGHMEM
 352                 memory_size = lowmem_size;
 353 #endif
 354         }
 355
 356         mm_cmdline_setup(); /* FIXME parse args from command line - not used */
 357
 358         /*
 359          * Map out the kernel text/data/bss from the available physical
 360          * memory.
 361          */
 362         kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
 363         /* kernel size */
 364         ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
 365         memblock_reserve(kstart, ksize);
 366
 367 #if defined(CONFIG_BLK_DEV_INITRD)
 368         /* Remove the init RAM disk from the available memory. */
 369         if (initrd_start) {
 370                 unsigned long size;
 371                 size = initrd_end - initrd_start;
 372                 memblock_reserve(__virt_to_phys(initrd_start), size);
 373         }
 374 #endif /* CONFIG_BLK_DEV_INITRD */
 375
 376         /* Initialize the MMU hardware */
 377         mmu_init_hw();
 378
 379         /* Map in all of RAM starting at CONFIG_KERNEL_START */
 380         mapin_ram();
 381
 382         /* Extend vmalloc and ioremap area as big as possible */
 383 #ifdef CONFIG_HIGHMEM
 384         ioremap_base = ioremap_bot = PKMAP_BASE;
 385 #else
 386         ioremap_base = ioremap_bot = FIXADDR_START;
 387 #endif
 388
 389         /* Initialize the context management stuff */
 390         mmu_context_init();
 391
 392         /* Shortly after that, the entire linear mapping will be available */
 393         /* This will also cause that unflatten device tree will be allocated
 394          * inside 768MB limit */
 395         memblock_set_current_limit(memory_start + lowmem_size - 1);
 396 }
 397
 398 /* This is only called until mem_init is done. */
 399 void __init *early_get_page(void)
 400 {
 401         void *p;
 402         if (init_bootmem_done) {
 403                 p = alloc_bootmem_pages(PAGE_SIZE);
 404         } else {
 405                 /*
 406                  * Mem start + kernel_tlb -> here is limit
 407                  * because of mem mapping from head.S
 408                  */
 409                 p = __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
 410                                         memory_start + kernel_tlb));
 411         }
 412         return p;
 413 }
 414
 415 #endif /* CONFIG_MMU */
 416
 417 void * __init_refok alloc_maybe_bootmem(size_t size, gfp_t mask)
 418 {
 419         if (mem_init_done)
 420                 return kmalloc(size, mask);
 421         else
 422                 return alloc_bootmem(size);
 423 }
 424
 425 void * __init_refok zalloc_maybe_bootmem(size_t size, gfp_t mask)
 426 {
 427         void *p;
 428
 429         if (mem_init_done)
 430                 p = kzalloc(size, mask);
 431         else {
 432                 p = alloc_bootmem(size);
 433                 if (p)
 434                         memset(p, 0, size);
 435         }
 436         return p;
 437 }