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   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/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/string.h>
  19 #include <linux/types.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/ptrace.h>
  22 #include <linux/mman.h>
  23 #include <linux/mm.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/highmem.h>
  26 #include <linux/swap.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/pfn.h>
  29
  30 #include <asm/asm-offsets.h>
  31 #include <asm/bootinfo.h>
  32 #include <asm/cachectl.h>
  33 #include <asm/cpu.h>
  34 #include <asm/dma.h>
  35 #include <asm/kmap_types.h>
  36 #include <asm/mmu_context.h>
  37 #include <asm/sections.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/pgalloc.h>
  40 #include <asm/tlb.h>
  41 #include <asm/fixmap.h>
  42
  43 /* Atomicity and interruptability */
  44 #ifdef CONFIG_MIPS_MT_SMTC
  45
  46 #include <asm/mipsmtregs.h>
  47
  48 #define ENTER_CRITICAL(flags) \
  49         { \
  50         unsigned int mvpflags; \
  51         local_irq_save(flags);\
  52         mvpflags = dvpe()
  53 #define EXIT_CRITICAL(flags) \
  54         evpe(mvpflags); \
  55         local_irq_restore(flags); \
  56         }
  57 #else
  58
  59 #define ENTER_CRITICAL(flags) local_irq_save(flags)
  60 #define EXIT_CRITICAL(flags) local_irq_restore(flags)
  61
  62 #endif /* CONFIG_MIPS_MT_SMTC */
  63
  64 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  65
  66 /*
  67  * We have up to 8 empty zeroed pages so we can map one of the right colour
  68  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  69  * where we have to avoid VCED / VECI exceptions for good performance at
  70  * any price.  Since page is never written to after the initialization we
  71  * don't have to care about aliases on other CPUs.
  72  */
  73 unsigned long empty_zero_page, zero_page_mask;
  74 EXPORT_SYMBOL_GPL(empty_zero_page);
  75
  76 /*
  77  * Not static inline because used by IP27 special magic initialization code
  78  */
  79 unsigned long setup_zero_pages(void)
  80 {
  81         unsigned int order;
  82         unsigned long size;
  83         struct page *page;
  84
  85         if (cpu_has_vce)
  86                 order = 3;
  87         else
  88                 order = 0;
  89
  90         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  91         if (!empty_zero_page)
  92                 panic("Oh boy, that early out of memory?");
  93
  94         page = virt_to_page((void *)empty_zero_page);
  95         split_page(page, order);
  96         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  97                 SetPageReserved(page);
  98                 page++;
  99         }
 100
 101         size = PAGE_SIZE << order;
 102         zero_page_mask = (size - 1) & PAGE_MASK;
 103
 104         return 1UL << order;
 105 }
 106
 107 /*
 108  * These are almost like kmap_atomic / kunmap_atmic except they take an
 109  * additional address argument as the hint.
 110  */
 111
 112 #define kmap_get_fixmap_pte(vaddr)                                      \
 113         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
 114
 115 #ifdef CONFIG_MIPS_MT_SMTC
 116 static pte_t *kmap_coherent_pte;
 117 static void __init kmap_coherent_init(void)
 118 {
 119         unsigned long vaddr;
 120
 121         /* cache the first coherent kmap pte */
 122         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 123         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 124 }
 125 #else
 126 static inline void kmap_coherent_init(void) {}
 127 #endif
 128
 129 void *kmap_coherent(struct page *page, unsigned long addr)
 130 {
 131         enum fixed_addresses idx;
 132         unsigned long vaddr, flags, entrylo;
 133         unsigned long old_ctx;
 134         pte_t pte;
 135         int tlbidx;
 136
 137         BUG_ON(Page_dcache_dirty(page));
 138
 139         inc_preempt_count();
 140         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 141 #ifdef CONFIG_MIPS_MT_SMTC
 142         idx += FIX_N_COLOURS * smp_processor_id();
 143 #endif
 144         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 145         pte = mk_pte(page, PAGE_KERNEL);
 146 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
 147         entrylo = pte.pte_high;
 148 #else
 149         entrylo = pte_val(pte) >> 6;
 150 #endif
 151
 152         ENTER_CRITICAL(flags);
 153         old_ctx = read_c0_entryhi();
 154         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 155         write_c0_entrylo0(entrylo);
 156         write_c0_entrylo1(entrylo);
 157 #ifdef CONFIG_MIPS_MT_SMTC
 158         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 159         /* preload TLB instead of local_flush_tlb_one() */
 160         mtc0_tlbw_hazard();
 161         tlb_probe();
 162         tlb_probe_hazard();
 163         tlbidx = read_c0_index();
 164         mtc0_tlbw_hazard();
 165         if (tlbidx < 0)
 166                 tlb_write_random();
 167         else
 168                 tlb_write_indexed();
 169 #else
 170         tlbidx = read_c0_wired();
 171         write_c0_wired(tlbidx + 1);
 172         write_c0_index(tlbidx);
 173         mtc0_tlbw_hazard();
 174         tlb_write_indexed();
 175 #endif
 176         tlbw_use_hazard();
 177         write_c0_entryhi(old_ctx);
 178         EXIT_CRITICAL(flags);
 179
 180         return (void*) vaddr;
 181 }
 182
 183 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 184
 185 void kunmap_coherent(void)
 186 {
 187 #ifndef CONFIG_MIPS_MT_SMTC
 188         unsigned int wired;
 189         unsigned long flags, old_ctx;
 190
 191         ENTER_CRITICAL(flags);
 192         old_ctx = read_c0_entryhi();
 193         wired = read_c0_wired() - 1;
 194         write_c0_wired(wired);
 195         write_c0_index(wired);
 196         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 197         write_c0_entrylo0(0);
 198         write_c0_entrylo1(0);
 199         mtc0_tlbw_hazard();
 200         tlb_write_indexed();
 201         tlbw_use_hazard();
 202         write_c0_entryhi(old_ctx);
 203         EXIT_CRITICAL(flags);
 204 #endif
 205         dec_preempt_count();
 206         preempt_check_resched();
 207 }
 208
 209 void copy_user_highpage(struct page *to, struct page *from,
 210         unsigned long vaddr, struct vm_area_struct *vma)
 211 {
 212         void *vfrom, *vto;
 213
 214         vto = kmap_atomic(to, KM_USER1);
 215         if (cpu_has_dc_aliases &&
 216             page_mapped(from) && !Page_dcache_dirty(from)) {
 217                 vfrom = kmap_coherent(from, vaddr);
 218                 copy_page(vto, vfrom);
 219                 kunmap_coherent();
 220         } else {
 221                 vfrom = kmap_atomic(from, KM_USER0);
 222                 copy_page(vto, vfrom);
 223                 kunmap_atomic(vfrom, KM_USER0);
 224         }
 225         if ((!cpu_has_ic_fills_f_dc) ||
 226             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 227                 flush_data_cache_page((unsigned long)vto);
 228         kunmap_atomic(vto, KM_USER1);
 229         /* Make sure this page is cleared on other CPU's too before using it */
 230         smp_wmb();
 231 }
 232
 233 void copy_to_user_page(struct vm_area_struct *vma,
 234         struct page *page, unsigned long vaddr, void *dst, const void *src,
 235         unsigned long len)
 236 {
 237         if (cpu_has_dc_aliases &&
 238             page_mapped(page) && !Page_dcache_dirty(page)) {
 239                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 240                 memcpy(vto, src, len);
 241                 kunmap_coherent();
 242         } else {
 243                 memcpy(dst, src, len);
 244                 if (cpu_has_dc_aliases)
 245                         SetPageDcacheDirty(page);
 246         }
 247         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 248                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 249 }
 250
 251 void copy_from_user_page(struct vm_area_struct *vma,
 252         struct page *page, unsigned long vaddr, void *dst, const void *src,
 253         unsigned long len)
 254 {
 255         if (cpu_has_dc_aliases &&
 256             page_mapped(page) && !Page_dcache_dirty(page)) {
 257                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 258                 memcpy(dst, vfrom, len);
 259                 kunmap_coherent();
 260         } else {
 261                 memcpy(dst, src, len);
 262                 if (cpu_has_dc_aliases)
 263                         SetPageDcacheDirty(page);
 264         }
 265 }
 266
 267 #ifdef CONFIG_HIGHMEM
 268 unsigned long highstart_pfn, highend_pfn;
 269
 270 pte_t *kmap_pte;
 271 pgprot_t kmap_prot;
 272
 273 static void __init kmap_init(void)
 274 {
 275         unsigned long kmap_vstart;
 276
 277         /* cache the first kmap pte */
 278         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 279         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 280
 281         kmap_prot = PAGE_KERNEL;
 282 }
 283 #endif /* CONFIG_HIGHMEM */
 284
 285 void __init fixrange_init(unsigned long start, unsigned long end,
 286         pgd_t *pgd_base)
 287 {
 288 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 289         pgd_t *pgd;
 290         pud_t *pud;
 291         pmd_t *pmd;
 292         pte_t *pte;
 293         int i, j, k;
 294         unsigned long vaddr;
 295
 296         vaddr = start;
 297         i = __pgd_offset(vaddr);
 298         j = __pud_offset(vaddr);
 299         k = __pmd_offset(vaddr);
 300         pgd = pgd_base + i;
 301
 302         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 303                 pud = (pud_t *)pgd;
 304                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 305                         pmd = (pmd_t *)pud;
 306                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 307                                 if (pmd_none(*pmd)) {
 308                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 309                                         set_pmd(pmd, __pmd((unsigned long)pte));
 310                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 311                                 }
 312                                 vaddr += PMD_SIZE;
 313                         }
 314                         k = 0;
 315                 }
 316                 j = 0;
 317         }
 318 #endif
 319 }
 320
 321 #ifndef CONFIG_NEED_MULTIPLE_NODES
 322 static int __init page_is_ram(unsigned long pagenr)
 323 {
 324         int i;
 325
 326         for (i = 0; i < boot_mem_map.nr_map; i++) {
 327                 unsigned long addr, end;
 328
 329                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 330                         /* not usable memory */
 331                         continue;
 332
 333                 addr = PFN_UP(boot_mem_map.map[i].addr);
 334                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 335                                boot_mem_map.map[i].size);
 336
 337                 if (pagenr >= addr && pagenr < end)
 338                         return 1;
 339         }
 340
 341         return 0;
 342 }
 343
 344 void __init paging_init(void)
 345 {
 346         unsigned long max_zone_pfns[MAX_NR_ZONES];
 347         unsigned long lastpfn;
 348
 349         pagetable_init();
 350
 351 #ifdef CONFIG_HIGHMEM
 352         kmap_init();
 353 #endif
 354         kmap_coherent_init();
 355
 356 #ifdef CONFIG_ZONE_DMA
 357         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 358 #endif
 359 #ifdef CONFIG_ZONE_DMA32
 360         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 361 #endif
 362         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 363         lastpfn = max_low_pfn;
 364 #ifdef CONFIG_HIGHMEM
 365         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 366         lastpfn = highend_pfn;
 367
 368         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 369                 printk(KERN_WARNING "This processor doesn't support highmem."
 370                        " %ldk highmem ignored\n",
 371                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 372                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 373                 lastpfn = max_low_pfn;
 374         }
 375 #endif
 376
 377         free_area_init_nodes(max_zone_pfns);
 378 }
 379
 380 static struct kcore_list kcore_mem, kcore_vmalloc;
 381 #ifdef CONFIG_64BIT
 382 static struct kcore_list kcore_kseg0;
 383 #endif
 384
 385 void __init mem_init(void)
 386 {
 387         unsigned long codesize, reservedpages, datasize, initsize;
 388         unsigned long tmp, ram;
 389
 390 #ifdef CONFIG_HIGHMEM
 391 #ifdef CONFIG_DISCONTIGMEM
 392 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 393 #endif
 394         max_mapnr = highend_pfn;
 395 #else
 396         max_mapnr = max_low_pfn;
 397 #endif
 398         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 399
 400         totalram_pages += free_all_bootmem();
 401         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 402
 403         reservedpages = ram = 0;
 404         for (tmp = 0; tmp < max_low_pfn; tmp++)
 405                 if (page_is_ram(tmp)) {
 406                         ram++;
 407                         if (PageReserved(pfn_to_page(tmp)))
 408                                 reservedpages++;
 409                 }
 410         num_physpages = ram;
 411
 412 #ifdef CONFIG_HIGHMEM
 413         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 414                 struct page *page = pfn_to_page(tmp);
 415
 416                 if (!page_is_ram(tmp)) {
 417                         SetPageReserved(page);
 418                         continue;
 419                 }
 420                 ClearPageReserved(page);
 421                 init_page_count(page);
 422                 __free_page(page);
 423                 totalhigh_pages++;
 424         }
 425         totalram_pages += totalhigh_pages;
 426         num_physpages += totalhigh_pages;
 427 #endif
 428
 429         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 430         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 431         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 432
 433 #ifdef CONFIG_64BIT
 434         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 435                 /* The -4 is a hack so that user tools don't have to handle
 436                    the overflow.  */
 437                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 438 #endif
 439         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 440         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 441                    VMALLOC_END-VMALLOC_START);
 442
 443         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 444                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 445                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 446                ram << (PAGE_SHIFT-10),
 447                codesize >> 10,
 448                reservedpages << (PAGE_SHIFT-10),
 449                datasize >> 10,
 450                initsize >> 10,
 451                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 452 }
 453 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 454
 455 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 456 {
 457         unsigned long pfn;
 458
 459         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 460                 struct page *page = pfn_to_page(pfn);
 461                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 462
 463                 ClearPageReserved(page);
 464                 init_page_count(page);
 465                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 466                 __free_page(page);
 467                 totalram_pages++;
 468         }
 469         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 470 }
 471
 472 #ifdef CONFIG_BLK_DEV_INITRD
 473 void free_initrd_mem(unsigned long start, unsigned long end)
 474 {
 475         free_init_pages("initrd memory",
 476                         virt_to_phys((void *)start),
 477                         virt_to_phys((void *)end));
 478 }
 479 #endif
 480
 481 void __init_refok free_initmem(void)
 482 {
 483         prom_free_prom_memory();
 484         free_init_pages("unused kernel memory",
 485                         __pa_symbol(&__init_begin),
 486                         __pa_symbol(&__init_end));
 487 }
 488
 489 unsigned long pgd_current[NR_CPUS];
 490 /*
 491  * On 64-bit we've got three-level pagetables with a slightly
 492  * different layout ...
 493  */
 494 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 495
 496 /*
 497  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 498  * are constants.  So we use the variants from asm-offset.h until that gcc
 499  * will officially be retired.
 500  */
 501 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 502 #ifdef CONFIG_64BIT
 503 #ifdef MODULE_START
 504 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 505 #endif
 506 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 507 #endif
 508 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);