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 #include <linux/kcore.h>
  33
  34 #include <asm/asm-offsets.h>
  35 #include <asm/bootinfo.h>
  36 #include <asm/cachectl.h>
  37 #include <asm/cpu.h>
  38 #include <asm/dma.h>
  39 #include <asm/kmap_types.h>
  40 #include <asm/maar.h>
  41 #include <asm/mmu_context.h>
  42 #include <asm/sections.h>
  43 #include <asm/pgtable.h>
  44 #include <asm/pgalloc.h>
  45 #include <asm/tlb.h>
  46 #include <asm/fixmap.h>
  47 #include <asm/maar.h>
  48
  49 /*
  50  * We have up to 8 empty zeroed pages so we can map one of the right colour
  51  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  52  * where we have to avoid VCED / VECI exceptions for good performance at
  53  * any price.  Since page is never written to after the initialization we
  54  * don't have to care about aliases on other CPUs.
  55  */
  56 unsigned long empty_zero_page, zero_page_mask;
  57 EXPORT_SYMBOL_GPL(empty_zero_page);
  58 EXPORT_SYMBOL(zero_page_mask);
  59
  60 /*
  61  * Not static inline because used by IP27 special magic initialization code
  62  */
  63 void setup_zero_pages(void)
  64 {
  65         unsigned int order, i;
  66         struct page *page;
  67
  68         if (cpu_has_vce)
  69                 order = 3;
  70         else
  71                 order = 0;
  72
  73         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  74         if (!empty_zero_page)
  75                 panic("Oh boy, that early out of memory?");
  76
  77         page = virt_to_page((void *)empty_zero_page);
  78         split_page(page, order);
  79         for (i = 0; i < (1 << order); i++, page++)
  80                 mark_page_reserved(page);
  81
  82         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  83 }
  84
  85 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
  86 {
  87         enum fixed_addresses idx;
  88         unsigned long vaddr, flags, entrylo;
  89         unsigned long old_ctx;
  90         pte_t pte;
  91         int tlbidx;
  92
  93         BUG_ON(Page_dcache_dirty(page));
  94
  95         preempt_disable();
  96         pagefault_disable();
  97         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
  98         idx += in_interrupt() ? FIX_N_COLOURS : 0;
  99         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 100         pte = mk_pte(page, prot);
 101 #if defined(CONFIG_XPA)
 102         entrylo = pte_to_entrylo(pte.pte_high);
 103 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 104         entrylo = pte.pte_high;
 105 #else
 106         entrylo = pte_to_entrylo(pte_val(pte));
 107 #endif
 108
 109         local_irq_save(flags);
 110         old_ctx = read_c0_entryhi();
 111         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 112         write_c0_entrylo0(entrylo);
 113         write_c0_entrylo1(entrylo);
 114 #ifdef CONFIG_XPA
 115         if (cpu_has_xpa) {
 116                 entrylo = (pte.pte_low & _PFNX_MASK);
 117                 writex_c0_entrylo0(entrylo);
 118                 writex_c0_entrylo1(entrylo);
 119         }
 120 #endif
 121         tlbidx = read_c0_wired();
 122         write_c0_wired(tlbidx + 1);
 123         write_c0_index(tlbidx);
 124         mtc0_tlbw_hazard();
 125         tlb_write_indexed();
 126         tlbw_use_hazard();
 127         write_c0_entryhi(old_ctx);
 128         local_irq_restore(flags);
 129
 130         return (void*) vaddr;
 131 }
 132
 133 void *kmap_coherent(struct page *page, unsigned long addr)
 134 {
 135         return __kmap_pgprot(page, addr, PAGE_KERNEL);
 136 }
 137
 138 void *kmap_noncoherent(struct page *page, unsigned long addr)
 139 {
 140         return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 141 }
 142
 143 void kunmap_coherent(void)
 144 {
 145         unsigned int wired;
 146         unsigned long flags, old_ctx;
 147
 148         local_irq_save(flags);
 149         old_ctx = read_c0_entryhi();
 150         wired = read_c0_wired() - 1;
 151         write_c0_wired(wired);
 152         write_c0_index(wired);
 153         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 154         write_c0_entrylo0(0);
 155         write_c0_entrylo1(0);
 156         mtc0_tlbw_hazard();
 157         tlb_write_indexed();
 158         tlbw_use_hazard();
 159         write_c0_entryhi(old_ctx);
 160         local_irq_restore(flags);
 161         pagefault_enable();
 162         preempt_enable();
 163 }
 164
 165 void copy_user_highpage(struct page *to, struct page *from,
 166         unsigned long vaddr, struct vm_area_struct *vma)
 167 {
 168         void *vfrom, *vto;
 169
 170         vto = kmap_atomic(to);
 171         if (cpu_has_dc_aliases &&
 172             page_mapcount(from) && !Page_dcache_dirty(from)) {
 173                 vfrom = kmap_coherent(from, vaddr);
 174                 copy_page(vto, vfrom);
 175                 kunmap_coherent();
 176         } else {
 177                 vfrom = kmap_atomic(from);
 178                 copy_page(vto, vfrom);
 179                 kunmap_atomic(vfrom);
 180         }
 181         if ((!cpu_has_ic_fills_f_dc) ||
 182             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 183                 flush_data_cache_page((unsigned long)vto);
 184         kunmap_atomic(vto);
 185         /* Make sure this page is cleared on other CPU's too before using it */
 186         smp_wmb();
 187 }
 188
 189 void copy_to_user_page(struct vm_area_struct *vma,
 190         struct page *page, unsigned long vaddr, void *dst, const void *src,
 191         unsigned long len)
 192 {
 193         if (cpu_has_dc_aliases &&
 194             page_mapcount(page) && !Page_dcache_dirty(page)) {
 195                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 196                 memcpy(vto, src, len);
 197                 kunmap_coherent();
 198         } else {
 199                 memcpy(dst, src, len);
 200                 if (cpu_has_dc_aliases)
 201                         SetPageDcacheDirty(page);
 202         }
 203         if (vma->vm_flags & VM_EXEC)
 204                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 205 }
 206
 207 void copy_from_user_page(struct vm_area_struct *vma,
 208         struct page *page, unsigned long vaddr, void *dst, const void *src,
 209         unsigned long len)
 210 {
 211         if (cpu_has_dc_aliases &&
 212             page_mapcount(page) && !Page_dcache_dirty(page)) {
 213                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 214                 memcpy(dst, vfrom, len);
 215                 kunmap_coherent();
 216         } else {
 217                 memcpy(dst, src, len);
 218                 if (cpu_has_dc_aliases)
 219                         SetPageDcacheDirty(page);
 220         }
 221 }
 222 EXPORT_SYMBOL_GPL(copy_from_user_page);
 223
 224 void __init fixrange_init(unsigned long start, unsigned long end,
 225         pgd_t *pgd_base)
 226 {
 227 #ifdef CONFIG_HIGHMEM
 228         pgd_t *pgd;
 229         pud_t *pud;
 230         pmd_t *pmd;
 231         pte_t *pte;
 232         int i, j, k;
 233         unsigned long vaddr;
 234
 235         vaddr = start;
 236         i = __pgd_offset(vaddr);
 237         j = __pud_offset(vaddr);
 238         k = __pmd_offset(vaddr);
 239         pgd = pgd_base + i;
 240
 241         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 242                 pud = (pud_t *)pgd;
 243                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 244                         pmd = (pmd_t *)pud;
 245                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 246                                 if (pmd_none(*pmd)) {
 247                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 248                                         set_pmd(pmd, __pmd((unsigned long)pte));
 249                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 250                                 }
 251                                 vaddr += PMD_SIZE;
 252                         }
 253                         k = 0;
 254                 }
 255                 j = 0;
 256         }
 257 #endif
 258 }
 259
 260 unsigned __weak platform_maar_init(unsigned num_pairs)
 261 {
 262         struct maar_config cfg[BOOT_MEM_MAP_MAX];
 263         unsigned i, num_configured, num_cfg = 0;
 264
 265         for (i = 0; i < boot_mem_map.nr_map; i++) {
 266                 switch (boot_mem_map.map[i].type) {
 267                 case BOOT_MEM_RAM:
 268                 case BOOT_MEM_INIT_RAM:
 269                         break;
 270                 default:
 271                         continue;
 272                 }
 273
 274                 /* Round lower up */
 275                 cfg[num_cfg].lower = boot_mem_map.map[i].addr;
 276                 cfg[num_cfg].lower = (cfg[num_cfg].lower + 0xffff) & ~0xffff;
 277
 278                 /* Round upper down */
 279                 cfg[num_cfg].upper = boot_mem_map.map[i].addr +
 280                                         boot_mem_map.map[i].size;
 281                 cfg[num_cfg].upper = (cfg[num_cfg].upper & ~0xffff) - 1;
 282
 283                 cfg[num_cfg].attrs = MIPS_MAAR_S;
 284                 num_cfg++;
 285         }
 286
 287         num_configured = maar_config(cfg, num_cfg, num_pairs);
 288         if (num_configured < num_cfg)
 289                 pr_warn("Not enough MAAR pairs (%u) for all bootmem regions (%u)\n",
 290                         num_pairs, num_cfg);
 291
 292         return num_configured;
 293 }
 294
 295 void maar_init(void)
 296 {
 297         unsigned num_maars, used, i;
 298         phys_addr_t lower, upper, attr;
 299         static struct {
 300                 struct maar_config cfgs[3];
 301                 unsigned used;
 302         } recorded = { { { 0 } }, 0 };
 303
 304         if (!cpu_has_maar)
 305                 return;
 306
 307         /* Detect the number of MAARs */
 308         write_c0_maari(~0);
 309         back_to_back_c0_hazard();
 310         num_maars = read_c0_maari() + 1;
 311
 312         /* MAARs should be in pairs */
 313         WARN_ON(num_maars % 2);
 314
 315         /* Set MAARs using values we recorded already */
 316         if (recorded.used) {
 317                 used = maar_config(recorded.cfgs, recorded.used, num_maars / 2);
 318                 BUG_ON(used != recorded.used);
 319         } else {
 320                 /* Configure the required MAARs */
 321                 used = platform_maar_init(num_maars / 2);
 322         }
 323
 324         /* Disable any further MAARs */
 325         for (i = (used * 2); i < num_maars; i++) {
 326                 write_c0_maari(i);
 327                 back_to_back_c0_hazard();
 328                 write_c0_maar(0);
 329                 back_to_back_c0_hazard();
 330         }
 331
 332         if (recorded.used)
 333                 return;
 334
 335         pr_info("MAAR configuration:\n");
 336         for (i = 0; i < num_maars; i += 2) {
 337                 write_c0_maari(i);
 338                 back_to_back_c0_hazard();
 339                 upper = read_c0_maar();
 340
 341                 write_c0_maari(i + 1);
 342                 back_to_back_c0_hazard();
 343                 lower = read_c0_maar();
 344
 345                 attr = lower & upper;
 346                 lower = (lower & MIPS_MAAR_ADDR) << 4;
 347                 upper = ((upper & MIPS_MAAR_ADDR) << 4) | 0xffff;
 348
 349                 pr_info("  [%d]: ", i / 2);
 350                 if (!(attr & MIPS_MAAR_V)) {
 351                         pr_cont("disabled\n");
 352                         continue;
 353                 }
 354
 355                 pr_cont("%pa-%pa", &lower, &upper);
 356
 357                 if (attr & MIPS_MAAR_S)
 358                         pr_cont(" speculate");
 359
 360                 pr_cont("\n");
 361
 362                 /* Record the setup for use on secondary CPUs */
 363                 if (used <= ARRAY_SIZE(recorded.cfgs)) {
 364                         recorded.cfgs[recorded.used].lower = lower;
 365                         recorded.cfgs[recorded.used].upper = upper;
 366                         recorded.cfgs[recorded.used].attrs = attr;
 367                         recorded.used++;
 368                 }
 369         }
 370 }
 371
 372 #ifndef CONFIG_NEED_MULTIPLE_NODES
 373 int page_is_ram(unsigned long pagenr)
 374 {
 375         int i;
 376
 377         for (i = 0; i < boot_mem_map.nr_map; i++) {
 378                 unsigned long addr, end;
 379
 380                 switch (boot_mem_map.map[i].type) {
 381                 case BOOT_MEM_RAM:
 382                 case BOOT_MEM_INIT_RAM:
 383                         break;
 384                 default:
 385                         /* not usable memory */
 386                         continue;
 387                 }
 388
 389                 addr = PFN_UP(boot_mem_map.map[i].addr);
 390                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 391                                boot_mem_map.map[i].size);
 392
 393                 if (pagenr >= addr && pagenr < end)
 394                         return 1;
 395         }
 396
 397         return 0;
 398 }
 399
 400 void __init paging_init(void)
 401 {
 402         unsigned long max_zone_pfns[MAX_NR_ZONES];
 403         unsigned long lastpfn __maybe_unused;
 404
 405         pagetable_init();
 406
 407 #ifdef CONFIG_HIGHMEM
 408         kmap_init();
 409 #endif
 410 #ifdef CONFIG_ZONE_DMA
 411         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 412 #endif
 413 #ifdef CONFIG_ZONE_DMA32
 414         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 415 #endif
 416         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 417         lastpfn = max_low_pfn;
 418 #ifdef CONFIG_HIGHMEM
 419         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 420         lastpfn = highend_pfn;
 421
 422         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 423                 printk(KERN_WARNING "This processor doesn't support highmem."
 424                        " %ldk highmem ignored\n",
 425                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 426                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 427                 lastpfn = max_low_pfn;
 428         }
 429 #endif
 430
 431         free_area_init_nodes(max_zone_pfns);
 432 }
 433
 434 #ifdef CONFIG_64BIT
 435 static struct kcore_list kcore_kseg0;
 436 #endif
 437
 438 static inline void mem_init_free_highmem(void)
 439 {
 440 #ifdef CONFIG_HIGHMEM
 441         unsigned long tmp;
 442
 443         if (cpu_has_dc_aliases)
 444                 return;
 445
 446         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 447                 struct page *page = pfn_to_page(tmp);
 448
 449                 if (!page_is_ram(tmp))
 450                         SetPageReserved(page);
 451                 else
 452                         free_highmem_page(page);
 453         }
 454 #endif
 455 }
 456
 457 void __init mem_init(void)
 458 {
 459 #ifdef CONFIG_HIGHMEM
 460 #ifdef CONFIG_DISCONTIGMEM
 461 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 462 #endif
 463         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 464 #else
 465         max_mapnr = max_low_pfn;
 466 #endif
 467         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 468
 469         maar_init();
 470         free_all_bootmem();
 471         setup_zero_pages();     /* Setup zeroed pages.  */
 472         mem_init_free_highmem();
 473         mem_init_print_info(NULL);
 474
 475 #ifdef CONFIG_64BIT
 476         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 477                 /* The -4 is a hack so that user tools don't have to handle
 478                    the overflow.  */
 479                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 480                                 0x80000000 - 4, KCORE_TEXT);
 481 #endif
 482 }
 483 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 484
 485 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 486 {
 487         unsigned long pfn;
 488
 489         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 490                 struct page *page = pfn_to_page(pfn);
 491                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 492
 493                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 494                 free_reserved_page(page);
 495         }
 496         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 497 }
 498
 499 #ifdef CONFIG_BLK_DEV_INITRD
 500 void free_initrd_mem(unsigned long start, unsigned long end)
 501 {
 502         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 503                            "initrd");
 504 }
 505 #endif
 506
 507 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 508
 509 void __ref free_initmem(void)
 510 {
 511         prom_free_prom_memory();
 512         /*
 513          * Let the platform define a specific function to free the
 514          * init section since EVA may have used any possible mapping
 515          * between virtual and physical addresses.
 516          */
 517         if (free_init_pages_eva)
 518                 free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 519         else
 520                 free_initmem_default(POISON_FREE_INITMEM);
 521 }
 522
 523 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 524 unsigned long pgd_current[NR_CPUS];
 525 #endif
 526
 527 /*
 528  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 529  * are constants.  So we use the variants from asm-offset.h until that gcc
 530  * will officially be retired.
 531  *
 532  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 533  * with a single LUI instruction in the TLB handlers.  If we used
 534  * __aligned(64K), its size would get rounded up to the alignment
 535  * size, and waste space.  So we place it in its own section and align
 536  * it in the linker script.
 537  */
 538 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 539 #ifndef __PAGETABLE_PMD_FOLDED
 540 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 541 #endif
 542 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;