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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
  75 /*
  76  * Not static inline because used by IP27 special magic initialization code
  77  */
  78 unsigned long setup_zero_pages(void)
  79 {
  80         unsigned int order;
  81         unsigned long size;
  82         struct page *page;
  83
  84         if (cpu_has_vce)
  85                 order = 3;
  86         else
  87                 order = 0;
  88
  89         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  90         if (!empty_zero_page)
  91                 panic("Oh boy, that early out of memory?");
  92
  93         page = virt_to_page((void *)empty_zero_page);
  94         split_page(page, order);
  95         while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
  96                 SetPageReserved(page);
  97                 page++;
  98         }
  99
 100         size = PAGE_SIZE << order;
 101         zero_page_mask = (size - 1) & PAGE_MASK;
 102
 103         return 1UL << order;
 104 }
 105
 106 /*
 107  * These are almost like kmap_atomic / kunmap_atmic except they take an
 108  * additional address argument as the hint.
 109  */
 110
 111 #define kmap_get_fixmap_pte(vaddr)                                      \
 112         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
 113
 114 #ifdef CONFIG_MIPS_MT_SMTC
 115 static pte_t *kmap_coherent_pte;
 116 static void __init kmap_coherent_init(void)
 117 {
 118         unsigned long vaddr;
 119
 120         /* cache the first coherent kmap pte */
 121         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
 122         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
 123 }
 124 #else
 125 static inline void kmap_coherent_init(void) {}
 126 #endif
 127
 128 void *kmap_coherent(struct page *page, unsigned long addr)
 129 {
 130         enum fixed_addresses idx;
 131         unsigned long vaddr, flags, entrylo;
 132         unsigned long old_ctx;
 133         pte_t pte;
 134         int tlbidx;
 135
 136         BUG_ON(Page_dcache_dirty(page));
 137
 138         inc_preempt_count();
 139         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
 140 #ifdef CONFIG_MIPS_MT_SMTC
 141         idx += FIX_N_COLOURS * smp_processor_id();
 142 #endif
 143         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 144         pte = mk_pte(page, PAGE_KERNEL);
 145 #if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32_R1)
 146         entrylo = pte.pte_high;
 147 #else
 148         entrylo = pte_val(pte) >> 6;
 149 #endif
 150
 151         ENTER_CRITICAL(flags);
 152         old_ctx = read_c0_entryhi();
 153         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 154         write_c0_entrylo0(entrylo);
 155         write_c0_entrylo1(entrylo);
 156 #ifdef CONFIG_MIPS_MT_SMTC
 157         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
 158         /* preload TLB instead of local_flush_tlb_one() */
 159         mtc0_tlbw_hazard();
 160         tlb_probe();
 161         tlb_probe_hazard();
 162         tlbidx = read_c0_index();
 163         mtc0_tlbw_hazard();
 164         if (tlbidx < 0)
 165                 tlb_write_random();
 166         else
 167                 tlb_write_indexed();
 168 #else
 169         tlbidx = read_c0_wired();
 170         write_c0_wired(tlbidx + 1);
 171         write_c0_index(tlbidx);
 172         mtc0_tlbw_hazard();
 173         tlb_write_indexed();
 174 #endif
 175         tlbw_use_hazard();
 176         write_c0_entryhi(old_ctx);
 177         EXIT_CRITICAL(flags);
 178
 179         return (void*) vaddr;
 180 }
 181
 182 #define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))
 183
 184 void kunmap_coherent(void)
 185 {
 186 #ifndef CONFIG_MIPS_MT_SMTC
 187         unsigned int wired;
 188         unsigned long flags, old_ctx;
 189
 190         ENTER_CRITICAL(flags);
 191         old_ctx = read_c0_entryhi();
 192         wired = read_c0_wired() - 1;
 193         write_c0_wired(wired);
 194         write_c0_index(wired);
 195         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 196         write_c0_entrylo0(0);
 197         write_c0_entrylo1(0);
 198         mtc0_tlbw_hazard();
 199         tlb_write_indexed();
 200         tlbw_use_hazard();
 201         write_c0_entryhi(old_ctx);
 202         EXIT_CRITICAL(flags);
 203 #endif
 204         dec_preempt_count();
 205         preempt_check_resched();
 206 }
 207
 208 void copy_user_highpage(struct page *to, struct page *from,
 209         unsigned long vaddr, struct vm_area_struct *vma)
 210 {
 211         void *vfrom, *vto;
 212
 213         vto = kmap_atomic(to, KM_USER1);
 214         if (cpu_has_dc_aliases && page_mapped(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 (((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc) ||
 224             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 225                 flush_data_cache_page((unsigned long)vto);
 226         kunmap_atomic(vto, KM_USER1);
 227         /* Make sure this page is cleared on other CPU's too before using it */
 228         smp_wmb();
 229 }
 230
 231 EXPORT_SYMBOL(copy_user_highpage);
 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 && page_mapped(page)) {
 238                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 239                 memcpy(vto, src, len);
 240                 kunmap_coherent();
 241         } else {
 242                 memcpy(dst, src, len);
 243                 if (cpu_has_dc_aliases)
 244                         SetPageDcacheDirty(page);
 245         }
 246         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 247                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 248 }
 249
 250 EXPORT_SYMBOL(copy_to_user_page);
 251
 252 void copy_from_user_page(struct vm_area_struct *vma,
 253         struct page *page, unsigned long vaddr, void *dst, const void *src,
 254         unsigned long len)
 255 {
 256         if (cpu_has_dc_aliases && page_mapped(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 EXPORT_SYMBOL(copy_from_user_page);
 268
 269
 270 #ifdef CONFIG_HIGHMEM
 271 unsigned long highstart_pfn, highend_pfn;
 272
 273 pte_t *kmap_pte;
 274 pgprot_t kmap_prot;
 275
 276 static void __init kmap_init(void)
 277 {
 278         unsigned long kmap_vstart;
 279
 280         /* cache the first kmap pte */
 281         kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 282         kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
 283
 284         kmap_prot = PAGE_KERNEL;
 285 }
 286 #endif /* CONFIG_HIGHMEM */
 287
 288 void __init fixrange_init(unsigned long start, unsigned long end,
 289         pgd_t *pgd_base)
 290 {
 291 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
 292         pgd_t *pgd;
 293         pud_t *pud;
 294         pmd_t *pmd;
 295         pte_t *pte;
 296         int i, j, k;
 297         unsigned long vaddr;
 298
 299         vaddr = start;
 300         i = __pgd_offset(vaddr);
 301         j = __pud_offset(vaddr);
 302         k = __pmd_offset(vaddr);
 303         pgd = pgd_base + i;
 304
 305         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 306                 pud = (pud_t *)pgd;
 307                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 308                         pmd = (pmd_t *)pud;
 309                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 310                                 if (pmd_none(*pmd)) {
 311                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 312                                         set_pmd(pmd, __pmd((unsigned long)pte));
 313                                         if (pte != pte_offset_kernel(pmd, 0))
 314                                                 BUG();
 315                                 }
 316                                 vaddr += PMD_SIZE;
 317                         }
 318                         k = 0;
 319                 }
 320                 j = 0;
 321         }
 322 #endif
 323 }
 324
 325 #ifndef CONFIG_NEED_MULTIPLE_NODES
 326 static int __init page_is_ram(unsigned long pagenr)
 327 {
 328         int i;
 329
 330         for (i = 0; i < boot_mem_map.nr_map; i++) {
 331                 unsigned long addr, end;
 332
 333                 if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
 334                         /* not usable memory */
 335                         continue;
 336
 337                 addr = PFN_UP(boot_mem_map.map[i].addr);
 338                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 339                                boot_mem_map.map[i].size);
 340
 341                 if (pagenr >= addr && pagenr < end)
 342                         return 1;
 343         }
 344
 345         return 0;
 346 }
 347
 348 void __init paging_init(void)
 349 {
 350         unsigned long zones_size[MAX_NR_ZONES] = { 0, };
 351 #ifndef CONFIG_FLATMEM
 352         unsigned long zholes_size[MAX_NR_ZONES] = { 0, };
 353         unsigned long i, j, pfn;
 354 #endif
 355
 356         pagetable_init();
 357
 358 #ifdef CONFIG_HIGHMEM
 359         kmap_init();
 360 #endif
 361         kmap_coherent_init();
 362
 363 #ifdef CONFIG_ZONE_DMA
 364         if (min_low_pfn < MAX_DMA_PFN && MAX_DMA_PFN <= max_low_pfn) {
 365                 zones_size[ZONE_DMA] = MAX_DMA_PFN - min_low_pfn;
 366                 zones_size[ZONE_NORMAL] = max_low_pfn - MAX_DMA_PFN;
 367         } else if (max_low_pfn < MAX_DMA_PFN)
 368                 zones_size[ZONE_DMA] = max_low_pfn - min_low_pfn;
 369         else
 370 #endif
 371         zones_size[ZONE_NORMAL] = max_low_pfn - min_low_pfn;
 372
 373 #ifdef CONFIG_HIGHMEM
 374         zones_size[ZONE_HIGHMEM] = highend_pfn - highstart_pfn;
 375
 376         if (cpu_has_dc_aliases && zones_size[ZONE_HIGHMEM]) {
 377                 printk(KERN_WARNING "This processor doesn't support highmem."
 378                        " %ldk highmem ignored\n", zones_size[ZONE_HIGHMEM]);
 379                 zones_size[ZONE_HIGHMEM] = 0;
 380         }
 381 #endif
 382
 383 #ifdef CONFIG_FLATMEM
 384         free_area_init(zones_size);
 385 #else
 386         pfn = min_low_pfn;
 387         for (i = 0; i < MAX_NR_ZONES; i++)
 388                 for (j = 0; j < zones_size[i]; j++, pfn++)
 389                         if (!page_is_ram(pfn))
 390                                 zholes_size[i]++;
 391         free_area_init_node(0, NODE_DATA(0), zones_size, 0, zholes_size);
 392 #endif
 393 }
 394
 395 static struct kcore_list kcore_mem, kcore_vmalloc;
 396 #ifdef CONFIG_64BIT
 397 static struct kcore_list kcore_kseg0;
 398 #endif
 399
 400 void __init mem_init(void)
 401 {
 402         unsigned long codesize, reservedpages, datasize, initsize;
 403         unsigned long tmp, ram;
 404
 405 #ifdef CONFIG_HIGHMEM
 406 #ifdef CONFIG_DISCONTIGMEM
 407 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 408 #endif
 409         max_mapnr = highend_pfn;
 410 #else
 411         max_mapnr = max_low_pfn;
 412 #endif
 413         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 414
 415         totalram_pages += free_all_bootmem();
 416         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages.  */
 417
 418         reservedpages = ram = 0;
 419         for (tmp = 0; tmp < max_low_pfn; tmp++)
 420                 if (page_is_ram(tmp)) {
 421                         ram++;
 422                         if (PageReserved(pfn_to_page(tmp)))
 423                                 reservedpages++;
 424                 }
 425         num_physpages = ram;
 426
 427 #ifdef CONFIG_HIGHMEM
 428         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 429                 struct page *page = pfn_to_page(tmp);
 430
 431                 if (!page_is_ram(tmp)) {
 432                         SetPageReserved(page);
 433                         continue;
 434                 }
 435                 ClearPageReserved(page);
 436                 init_page_count(page);
 437                 __free_page(page);
 438                 totalhigh_pages++;
 439         }
 440         totalram_pages += totalhigh_pages;
 441         num_physpages += totalhigh_pages;
 442 #endif
 443
 444         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 445         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 446         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 447
 448 #ifdef CONFIG_64BIT
 449         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 450                 /* The -4 is a hack so that user tools don't have to handle
 451                    the overflow.  */
 452                 kclist_add(&kcore_kseg0, (void *) CKSEG0, 0x80000000 - 4);
 453 #endif
 454         kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
 455         kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
 456                    VMALLOC_END-VMALLOC_START);
 457
 458         printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
 459                "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
 460                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 461                ram << (PAGE_SHIFT-10),
 462                codesize >> 10,
 463                reservedpages << (PAGE_SHIFT-10),
 464                datasize >> 10,
 465                initsize >> 10,
 466                (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
 467 }
 468 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 469
 470 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 471 {
 472         unsigned long pfn;
 473
 474         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 475                 struct page *page = pfn_to_page(pfn);
 476                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 477
 478                 ClearPageReserved(page);
 479                 init_page_count(page);
 480                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 481                 __free_page(page);
 482                 totalram_pages++;
 483         }
 484         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 485 }
 486
 487 #ifdef CONFIG_BLK_DEV_INITRD
 488 void free_initrd_mem(unsigned long start, unsigned long end)
 489 {
 490         free_init_pages("initrd memory",
 491                         virt_to_phys((void *)start),
 492                         virt_to_phys((void *)end));
 493 }
 494 #endif
 495
 496 void __init_refok free_initmem(void)
 497 {
 498         prom_free_prom_memory();
 499         free_init_pages("unused kernel memory",
 500                         __pa_symbol(&__init_begin),
 501                         __pa_symbol(&__init_end));
 502 }
 503
 504 unsigned long pgd_current[NR_CPUS];
 505 /*
 506  * On 64-bit we've got three-level pagetables with a slightly
 507  * different layout ...
 508  */
 509 #define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))
 510
 511 /*
 512  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 513  * are constants.  So we use the variants from asm-offset.h until that gcc
 514  * will officially be retired.
 515  */
 516 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
 517 #ifdef CONFIG_64BIT
 518 #ifdef MODULE_START
 519 pgd_t module_pg_dir[PTRS_PER_PGD] __page_aligned(PGD_ORDER);
 520 #endif
 521 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
 522 #endif
 523 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);