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

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994 - 2000 Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
   9  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
  10  */
  11 #include <linux/bug.h>
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/signal.h>
  15 #include <linux/sched.h>
  16 #include <linux/smp.h>
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/string.h>
  20 #include <linux/types.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/mman.h>
  24 #include <linux/mm.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/highmem.h>
  27 #include <linux/swap.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/pfn.h>
  30 #include <linux/hardirq.h>
  31 #include <linux/gfp.h>
  32
  33 #include <asm/asm-offsets.h>
  34 #include <asm/bootinfo.h>
  35 #include <asm/cachectl.h>
  36 #include <asm/cpu.h>
  37 #include <asm/dma.h>
  38 #include <asm/kmap_types.h>
  39 #include <asm/mmu_context.h>
  40 #include <asm/sections.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/pgalloc.h>
  43 #include <asm/tlb.h>
  44 #include <asm/fixmap.h>
  45
  46 /* Atomicity and interruptability */
  47 #ifdef CONFIG_MIPS_MT_SMTC
  48
  49 #include <asm/mipsmtregs.h>
  50
  51 #define ENTER_CRITICAL(flags) \
  52         { \
  53         unsigned int mvpflags; \
  54         local_irq_save(flags);\
  55         mvpflags = dvpe()
  56 #define EXIT_CRITICAL(flags) \
  57         evpe(mvpflags); \
  58         local_irq_restore(flags); \
  59         }
  60 #else
  61
  62 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  63 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  64
  65 #endif /* CONFIG_MIPS_MT_SMTC */
  66
  67 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  68
  69 /*
  70  * We have up to 8 empty zeroed pages so we can map one of the right colour
  71  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  72  * where we have to avoid VCED / VECI exceptions for good performance at
  73  * any price.  Since page is never written to after the initialization we
  74  * don't have to care about aliases on other CPUs.
  75  */
  76 unsigned long empty_zero_page, zero_page_mask;
  77 EXPORT_SYMBOL_GPL(empty_zero_page);
  78
  79 /*
  80  * Not static inline because used by IP27 special magic initialization code
  81  */
  82 unsigned long setup_zero_pages(void)
  83 {
  84         unsigned int order;
  85         unsigned long size;
  86         struct page *page;
  87
  88         if (cpu_has_vce)
  89                 order = 3;
  90         else
  91                 order = 0;
  92
  93         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  94         if (!empty_zero_page)
  95                 panic("Oh boy, that early out of memory?");
  96
  97         page = virt_to_page((void *)empty_zero_page);
  98         split_page(page, order);
  99         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
 100                 SetPageReserved(page);
 101                 page++;
 102         }
 103
 104         size = PAGE_SIZE << order;
 105         zero_page_mask = (size - 1) & PAGE_MASK;
 106
 107         return 1UL << order;
 108 }
 109
 110 #ifdef CONFIG_MIPS_MT_SMTC
 111 static pte_t *kmap_coherent_pte;
 112 static void __init kmap_coherent_init(void)
 113 {
 114         unsigned long vaddr;
 115
 116         /* cache the first coherent kmap pte */
 117         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 118         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 119 }
 120 #else
 121 static inline void kmap_coherent_init(void) {}
 122 #endif
 123
 124 void *kmap_coherent(struct page *page, unsigned long addr)
 125 {
 126         enum fixed_addresses idx;
 127         unsigned long vaddr, flags, entrylo;
 128         unsigned long old_ctx;
 129         pte_t pte;
 130         int tlbidx;
 131
 132         BUG_ON(Page_dcache_dirty(page));
 133
 134         inc_preempt_count();
 135         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 136 #ifdef CONFIG_MIPS_MT_SMTC
 137         idx += FIX_N_COLOURS * smp_processor_id() +
 138                 (in_interrupt() ? (FIX_N_COLOURS * NR_CPUS) : 0);
 139 #else
 140         idx += in_interrupt() ? FIX_N_COLOURS : 0;
 141 #endif
 142         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 143         pte = mk_pte(page, PAGE_KERNEL);
 144 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 145         entrylo = pte.pte_high;
 146 #else
 147         entrylo = pte_to_entrylo(pte_val(pte));
 148 #endif
 149
 150         ENTER_CRITICAL(flags);
 151         old_ctx = read_c0_entryhi();
 152         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 153         write_c0_entrylo0(entrylo);
 154         write_c0_entrylo1(entrylo);
 155 #ifdef CONFIG_MIPS_MT_SMTC
 156         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 157         /* preload TLB instead of local_flush_tlb_one() */
 158         mtc0_tlbw_hazard();
 159         tlb_probe();
 160         tlb_probe_hazard();
 161         tlbidx = read_c0_index();
 162         mtc0_tlbw_hazard();
 163         if (tlbidx < 0)
 164                 tlb_write_random();
 165         else
 166                 tlb_write_indexed();
 167 #else
 168         tlbidx = read_c0_wired();
 169         write_c0_wired(tlbidx + 1);
 170         write_c0_index(tlbidx);
 171         mtc0_tlbw_hazard();
 172         tlb_write_indexed();
 173 #endif
 174         tlbw_use_hazard();
 175         write_c0_entryhi(old_ctx);
 176         EXIT_CRITICAL(flags);
 177
 178         return (void*) vaddr;
 179 }
 180
 181 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 182
 183 void kunmap_coherent(void)
 184 {
 185 #ifndef CONFIG_MIPS_MT_SMTC
 186         unsigned int wired;
 187         unsigned long flags, old_ctx;
 188
 189         ENTER_CRITICAL(flags);
 190         old_ctx = read_c0_entryhi();
 191         wired = read_c0_wired() - 1;
 192         write_c0_wired(wired);
 193         write_c0_index(wired);
 194         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 195         write_c0_entrylo0(0);
 196         write_c0_entrylo1(0);
 197         mtc0_tlbw_hazard();
 198         tlb_write_indexed();
 199         tlbw_use_hazard();
 200         write_c0_entryhi(old_ctx);
 201         EXIT_CRITICAL(flags);
 202 #endif
 203         dec_preempt_count();
 204         preempt_check_resched();
 205 }
 206
 207 void copy_user_highpage(struct page *to, struct page *from,
 208         unsigned long vaddr, struct vm_area_struct *vma)
 209 {
 210         void *vfrom, *vto;
 211
 212         vto = kmap_atomic(to, KM_USER1);
 213         if (cpu_has_dc_aliases &&
 214             page_mapped(from) && !Page_dcache_dirty(from)) {
 215                 vfrom = kmap_coherent(from, vaddr);
 216                 copy_page(vto, vfrom);
 217                 kunmap_coherent();
 218         } else {
 219                 vfrom = kmap_atomic(from, KM_USER0);
 220                 copy_page(vto, vfrom);
 221                 kunmap_atomic(vfrom, KM_USER0);
 222         }
 223         if (cpu_has_dc_aliases)
 224                 SetPageDcacheDirty(to);
 225         if (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) ||
 226             cpu_has_vtag_dcache || (cpu_has_dc_aliases &&
 227              pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))) {
 228                 flush_data_cache_page((unsigned long)vto);
 229                 if (cpu_has_dc_aliases)
 230                         ClearPageDcacheDirty(to);
 231         }
 232         kunmap_atomic(vto, KM_USER1);
 233         /* Make sure this page is cleared on other CPU's too before using it */
 234         smp_wmb();
 235 }
 236
 237 void copy_to_user_page(struct vm_area_struct *vma,
 238         struct page *page, unsigned long vaddr, void *dst, const void *src,
 239         unsigned long len)
 240 {
 241         if (cpu_has_dc_aliases &&
 242             page_mapped(page) && !Page_dcache_dirty(page)) {
 243                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 244                 memcpy(vto, src, len);
 245                 kunmap_coherent();
 246         } else {
 247                 memcpy(dst, src, len);
 248                 if (cpu_has_dc_aliases)
 249                         SetPageDcacheDirty(page);
 250         }
 251         if (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) ||
 252             (Page_dcache_dirty(page) &&
 253              pages_do_alias((unsigned long)dst & PAGE_MASK,
 254                             vaddr & PAGE_MASK))) {
 255                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 256                 if (cpu_has_dc_aliases)
 257                         ClearPageDcacheDirty(page);
 258         }
 259 }
 260
 261 void copy_from_user_page(struct vm_area_struct *vma,
 262         struct page *page, unsigned long vaddr, void *dst, const void *src,
 263         unsigned long len)
 264 {
 265         if (cpu_has_dc_aliases &&
 266             page_mapped(page) && !Page_dcache_dirty(page)) {
 267                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 268                 memcpy(dst, vfrom, len);
 269                 kunmap_coherent();
 270         } else
 271                 memcpy(dst, src, len);
 272 }
 273
 274 void __init fixrange_init(unsigned long start, unsigned long end,
 275         pgd_t *pgd_base)
 276 {
 277 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 278         pgd_t *pgd;
 279         pud_t *pud;
 280         pmd_t *pmd;
 281         pte_t *pte;
 282         int i, j, k;
 283         unsigned long vaddr;
 284
 285         vaddr = start;
 286         i = __pgd_offset(vaddr);
 287         j = __pud_offset(vaddr);
 288         k = __pmd_offset(vaddr);
 289         pgd = pgd_base + i;
 290
 291         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 292                 pud = (pud_t *)pgd;
 293                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 294                         pmd = (pmd_t *)pud;
 295                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 296                                 if (pmd_none(*pmd)) {
 297                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 298                                         set_pmd(pmd, __pmd((unsigned long)pte));
 299                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 300                                 }
 301                                 vaddr += PMD_SIZE;
 302                         }
 303                         k = 0;
 304                 }
 305                 j = 0;
 306         }
 307 #endif
 308 }
 309
 310 #ifndef CONFIG_NEED_MULTIPLE_NODES
 311 int page_is_ram(unsigned long pagenr)
 312 {
 313         int i;
 314
 315         for (i = 0; i < boot_mem_map.nr_map; i++) {
 316                 unsigned long addr, end;
 317
 318                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 319                         /* not usable memory */
 320                         continue;
 321
 322                 addr = PFN_UP(boot_mem_map.map[i].addr);
 323                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 324                                boot_mem_map.map[i].size);
 325
 326                 if (pagenr >= addr && pagenr < end)
 327                         return 1;
 328         }
 329
 330         return 0;
 331 }
 332
 333 void __init paging_init(void)
 334 {
 335         unsigned long max_zone_pfns[MAX_NR_ZONES];
 336         unsigned long lastpfn __maybe_unused;
 337
 338         pagetable_init();
 339
 340 #ifdef CONFIG_HIGHMEM
 341         kmap_init();
 342 #endif
 343         kmap_coherent_init();
 344
 345 #ifdef CONFIG_ZONE_DMA
 346         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 347 #endif
 348 #ifdef CONFIG_ZONE_DMA32
 349         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 350 #endif
 351         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 352         lastpfn = max_low_pfn;
 353 #ifdef CONFIG_HIGHMEM
 354         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 355         lastpfn = highend_pfn;
 356
 357         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 358                 printk(KERN_WARNING "This processor doesn't support highmem."
 359                        " %ldk highmem ignored\n",
 360                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 361                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 362                 lastpfn = max_low_pfn;
 363         }
 364 #endif
 365
 366         free_area_init_nodes(max_zone_pfns);
 367 }
 368
 369 #ifdef CONFIG_64BIT
 370 static struct kcore_list kcore_kseg0;
 371 #endif
 372
 373 void __init mem_init(void)
 374 {
 375         unsigned long codesize, reservedpages, datasize, initsize;
 376         unsigned long tmp, ram;
 377
 378 #ifdef CONFIG_HIGHMEM
 379 #ifdef CONFIG_DISCONTIGMEM
 380 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 381 #endif
 382         max_mapnr = highend_pfn;
 383 #else
 384         max_mapnr = max_low_pfn;
 385 #endif
 386         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 387
 388         totalram_pages += free_all_bootmem();
 389         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 390
 391         reservedpages = ram = 0;
 392         for (tmp = 0; tmp < max_low_pfn; tmp++)
 393                 if (page_is_ram(tmp)) {
 394                         ram++;
 395                         if (PageReserved(pfn_to_page(tmp)))
 396                                 reservedpages++;
 397                 }
 398         num_physpages = ram;
 399
 400 #ifdef CONFIG_HIGHMEM
 401         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 402                 struct page *page = pfn_to_page(tmp);
 403
 404                 if (!page_is_ram(tmp)) {
 405                         SetPageReserved(page);
 406                         continue;
 407                 }
 408                 ClearPageReserved(page);
 409                 init_page_count(page);
 410                 __free_page(page);
 411                 totalhigh_pages++;
 412         }
 413         totalram_pages += totalhigh_pages;
 414         num_physpages += totalhigh_pages;
 415 #endif
 416
 417         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 418         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 419         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 420
 421 #ifdef CONFIG_64BIT
 422         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 423                 /* The -4 is a hack so that user tools don't have to handle
 424                    the overflow.  */
 425                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 426                                 0x80000000 - 4, KCORE_TEXT);
 427 #endif
 428
 429         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 430                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 431                nr_free_pages() << (PAGE_SHIFT-10),
 432                ram << (PAGE_SHIFT-10),
 433                codesize >> 10,
 434                reservedpages << (PAGE_SHIFT-10),
 435                datasize >> 10,
 436                initsize >> 10,
 437                totalhigh_pages << (PAGE_SHIFT-10));
 438 }
 439 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 440
 441 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 442 {
 443         unsigned long pfn;
 444
 445         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 446                 struct page *page = pfn_to_page(pfn);
 447                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 448
 449                 ClearPageReserved(page);
 450                 init_page_count(page);
 451                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 452                 __free_page(page);
 453                 totalram_pages++;
 454         }
 455         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 456 }
 457
 458 #ifdef CONFIG_BLK_DEV_INITRD
 459 void free_initrd_mem(unsigned long start, unsigned long end)
 460 {
 461         free_init_pages("initrd memory",
 462                         virt_to_phys((void *)start),
 463                         virt_to_phys((void *)end));
 464 }
 465 #endif
 466
 467 void __init_refok free_initmem(void)
 468 {
 469         prom_free_prom_memory();
 470         free_init_pages("unused kernel memory",
 471                         __pa_symbol(&__init_begin),
 472                         __pa_symbol(&__init_end));
 473 }
 474
 475 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 476 unsigned long pgd_current[NR_CPUS];
 477 #endif
 478 /*
 479  * On 64-bit we've got three-level pagetables with a slightly
 480  * different layout ...
 481  */
 482 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 483
 484 /*
 485  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 486  * are constants.  So we use the variants from asm-offset.h until that gcc
 487  * will officially be retired.
 488  */
 489 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 490 #ifndef __PAGETABLE_PMD_FOLDED
 491 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 492 #endif
 493 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);