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
  48 /*
  49  * We have up to 8 empty zeroed pages so we can map one of the right colour
  50  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  51  * where we have to avoid VCED / VECI exceptions for good performance at
  52  * any price.  Since page is never written to after the initialization we
  53  * don't have to care about aliases on other CPUs.
  54  */
  55 unsigned long empty_zero_page, zero_page_mask;
  56 EXPORT_SYMBOL_GPL(empty_zero_page);
  57 EXPORT_SYMBOL(zero_page_mask);
  58
  59 /*
  60  * Not static inline because used by IP27 special magic initialization code
  61  */
  62 void setup_zero_pages(void)
  63 {
  64         unsigned int order, i;
  65         struct page *page;
  66
  67         if (cpu_has_vce)
  68                 order = 3;
  69         else
  70                 order = 0;
  71
  72         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  73         if (!empty_zero_page)
  74                 panic("Oh boy, that early out of memory?");
  75
  76         page = virt_to_page((void *)empty_zero_page);
  77         split_page(page, order);
  78         for (i = 0; i < (1 << order); i++, page++)
  79                 mark_page_reserved(page);
  80
  81         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  82 }
  83
  84 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
  85 {
  86         enum fixed_addresses idx;
  87         unsigned long vaddr, flags, entrylo;
  88         unsigned long old_ctx;
  89         pte_t pte;
  90         int tlbidx;
  91
  92         BUG_ON(Page_dcache_dirty(page));
  93
  94         preempt_disable();
  95         pagefault_disable();
  96         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
  97         idx += in_interrupt() ? FIX_N_COLOURS : 0;
  98         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
  99         pte = mk_pte(page, prot);
 100 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 101         entrylo = pte_to_entrylo(pte.pte_high);
 102 #else
 103         entrylo = pte_to_entrylo(pte_val(pte));
 104 #endif
 105
 106         local_irq_save(flags);
 107         old_ctx = read_c0_entryhi();
 108         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 109         write_c0_entrylo0(entrylo);
 110         write_c0_entrylo1(entrylo);
 111 #ifdef CONFIG_XPA
 112         entrylo = (pte.pte_low & _PFNX_MASK);
 113         writex_c0_entrylo0(entrylo);
 114         writex_c0_entrylo1(entrylo);
 115 #endif
 116         tlbidx = read_c0_wired();
 117         write_c0_wired(tlbidx + 1);
 118         write_c0_index(tlbidx);
 119         mtc0_tlbw_hazard();
 120         tlb_write_indexed();
 121         tlbw_use_hazard();
 122         write_c0_entryhi(old_ctx);
 123         local_irq_restore(flags);
 124
 125         return (void*) vaddr;
 126 }
 127
 128 void *kmap_coherent(struct page *page, unsigned long addr)
 129 {
 130         return __kmap_pgprot(page, addr, PAGE_KERNEL);
 131 }
 132
 133 void *kmap_noncoherent(struct page *page, unsigned long addr)
 134 {
 135         return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 136 }
 137
 138 void kunmap_coherent(void)
 139 {
 140         unsigned int wired;
 141         unsigned long flags, old_ctx;
 142
 143         local_irq_save(flags);
 144         old_ctx = read_c0_entryhi();
 145         wired = read_c0_wired() - 1;
 146         write_c0_wired(wired);
 147         write_c0_index(wired);
 148         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 149         write_c0_entrylo0(0);
 150         write_c0_entrylo1(0);
 151         mtc0_tlbw_hazard();
 152         tlb_write_indexed();
 153         tlbw_use_hazard();
 154         write_c0_entryhi(old_ctx);
 155         local_irq_restore(flags);
 156         pagefault_enable();
 157         preempt_enable();
 158 }
 159
 160 void copy_user_highpage(struct page *to, struct page *from,
 161         unsigned long vaddr, struct vm_area_struct *vma)
 162 {
 163         void *vfrom, *vto;
 164
 165         vto = kmap_atomic(to);
 166         if (cpu_has_dc_aliases &&
 167             page_mapped(from) && !Page_dcache_dirty(from)) {
 168                 vfrom = kmap_coherent(from, vaddr);
 169                 copy_page(vto, vfrom);
 170                 kunmap_coherent();
 171         } else {
 172                 vfrom = kmap_atomic(from);
 173                 copy_page(vto, vfrom);
 174                 kunmap_atomic(vfrom);
 175         }
 176         if ((!cpu_has_ic_fills_f_dc) ||
 177             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 178                 flush_data_cache_page((unsigned long)vto);
 179         kunmap_atomic(vto);
 180         /* Make sure this page is cleared on other CPU's too before using it */
 181         smp_wmb();
 182 }
 183
 184 void copy_to_user_page(struct vm_area_struct *vma,
 185         struct page *page, unsigned long vaddr, void *dst, const void *src,
 186         unsigned long len)
 187 {
 188         if (cpu_has_dc_aliases &&
 189             page_mapped(page) && !Page_dcache_dirty(page)) {
 190                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 191                 memcpy(vto, src, len);
 192                 kunmap_coherent();
 193         } else {
 194                 memcpy(dst, src, len);
 195                 if (cpu_has_dc_aliases)
 196                         SetPageDcacheDirty(page);
 197         }
 198         if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
 199                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 200 }
 201
 202 void copy_from_user_page(struct vm_area_struct *vma,
 203         struct page *page, unsigned long vaddr, void *dst, const void *src,
 204         unsigned long len)
 205 {
 206         if (cpu_has_dc_aliases &&
 207             page_mapped(page) && !Page_dcache_dirty(page)) {
 208                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 209                 memcpy(dst, vfrom, len);
 210                 kunmap_coherent();
 211         } else {
 212                 memcpy(dst, src, len);
 213                 if (cpu_has_dc_aliases)
 214                         SetPageDcacheDirty(page);
 215         }
 216 }
 217 EXPORT_SYMBOL_GPL(copy_from_user_page);
 218
 219 void __init fixrange_init(unsigned long start, unsigned long end,
 220         pgd_t *pgd_base)
 221 {
 222 #ifdef CONFIG_HIGHMEM
 223         pgd_t *pgd;
 224         pud_t *pud;
 225         pmd_t *pmd;
 226         pte_t *pte;
 227         int i, j, k;
 228         unsigned long vaddr;
 229
 230         vaddr = start;
 231         i = __pgd_offset(vaddr);
 232         j = __pud_offset(vaddr);
 233         k = __pmd_offset(vaddr);
 234         pgd = pgd_base + i;
 235
 236         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 237                 pud = (pud_t *)pgd;
 238                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 239                         pmd = (pmd_t *)pud;
 240                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 241                                 if (pmd_none(*pmd)) {
 242                                         pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 243                                         set_pmd(pmd, __pmd((unsigned long)pte));
 244                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 245                                 }
 246                                 vaddr += PMD_SIZE;
 247                         }
 248                         k = 0;
 249                 }
 250                 j = 0;
 251         }
 252 #endif
 253 }
 254
 255 #ifndef CONFIG_NEED_MULTIPLE_NODES
 256 int page_is_ram(unsigned long pagenr)
 257 {
 258         int i;
 259
 260         for (i = 0; i < boot_mem_map.nr_map; i++) {
 261                 unsigned long addr, end;
 262
 263                 switch (boot_mem_map.map[i].type) {
 264                 case BOOT_MEM_RAM:
 265                 case BOOT_MEM_INIT_RAM:
 266                         break;
 267                 default:
 268                         /* not usable memory */
 269                         continue;
 270                 }
 271
 272                 addr = PFN_UP(boot_mem_map.map[i].addr);
 273                 end = PFN_DOWN(boot_mem_map.map[i].addr +
 274                                boot_mem_map.map[i].size);
 275
 276                 if (pagenr >= addr && pagenr < end)
 277                         return 1;
 278         }
 279
 280         return 0;
 281 }
 282
 283 void __init paging_init(void)
 284 {
 285         unsigned long max_zone_pfns[MAX_NR_ZONES];
 286         unsigned long lastpfn __maybe_unused;
 287
 288         pagetable_init();
 289
 290 #ifdef CONFIG_HIGHMEM
 291         kmap_init();
 292 #endif
 293 #ifdef CONFIG_ZONE_DMA
 294         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 295 #endif
 296 #ifdef CONFIG_ZONE_DMA32
 297         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 298 #endif
 299         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 300         lastpfn = max_low_pfn;
 301 #ifdef CONFIG_HIGHMEM
 302         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 303         lastpfn = highend_pfn;
 304
 305         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 306                 printk(KERN_WARNING "This processor doesn't support highmem."
 307                        " %ldk highmem ignored\n",
 308                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 309                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 310                 lastpfn = max_low_pfn;
 311         }
 312 #endif
 313
 314         free_area_init_nodes(max_zone_pfns);
 315 }
 316
 317 #ifdef CONFIG_64BIT
 318 static struct kcore_list kcore_kseg0;
 319 #endif
 320
 321 static inline void mem_init_free_highmem(void)
 322 {
 323 #ifdef CONFIG_HIGHMEM
 324         unsigned long tmp;
 325
 326         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 327                 struct page *page = pfn_to_page(tmp);
 328
 329                 if (!page_is_ram(tmp))
 330                         SetPageReserved(page);
 331                 else
 332                         free_highmem_page(page);
 333         }
 334 #endif
 335 }
 336
 337 unsigned __weak platform_maar_init(unsigned num_pairs)
 338 {
 339         struct maar_config cfg[BOOT_MEM_MAP_MAX];
 340         unsigned i, num_configured, num_cfg = 0;
 341         phys_addr_t skip;
 342
 343         for (i = 0; i < boot_mem_map.nr_map; i++) {
 344                 switch (boot_mem_map.map[i].type) {
 345                 case BOOT_MEM_RAM:
 346                 case BOOT_MEM_INIT_RAM:
 347                         break;
 348                 default:
 349                         continue;
 350                 }
 351
 352                 skip = 0x10000 - (boot_mem_map.map[i].addr & 0xffff);
 353
 354                 cfg[num_cfg].lower = boot_mem_map.map[i].addr;
 355                 cfg[num_cfg].lower += skip;
 356
 357                 cfg[num_cfg].upper = cfg[num_cfg].lower;
 358                 cfg[num_cfg].upper += boot_mem_map.map[i].size - 1;
 359                 cfg[num_cfg].upper -= skip;
 360
 361                 cfg[num_cfg].attrs = MIPS_MAAR_S;
 362                 num_cfg++;
 363         }
 364
 365         num_configured = maar_config(cfg, num_cfg, num_pairs);
 366         if (num_configured < num_cfg)
 367                 pr_warn("Not enough MAAR pairs (%u) for all bootmem regions (%u)\n",
 368                         num_pairs, num_cfg);
 369
 370         return num_configured;
 371 }
 372
 373 static void maar_init(void)
 374 {
 375         unsigned num_maars, used, i;
 376
 377         if (!cpu_has_maar)
 378                 return;
 379
 380         /* Detect the number of MAARs */
 381         write_c0_maari(~0);
 382         back_to_back_c0_hazard();
 383         num_maars = read_c0_maari() + 1;
 384
 385         /* MAARs should be in pairs */
 386         WARN_ON(num_maars % 2);
 387
 388         /* Configure the required MAARs */
 389         used = platform_maar_init(num_maars / 2);
 390
 391         /* Disable any further MAARs */
 392         for (i = (used * 2); i < num_maars; i++) {
 393                 write_c0_maari(i);
 394                 back_to_back_c0_hazard();
 395                 write_c0_maar(0);
 396                 back_to_back_c0_hazard();
 397         }
 398 }
 399
 400 void __init mem_init(void)
 401 {
 402 #ifdef CONFIG_HIGHMEM
 403 #ifdef CONFIG_DISCONTIGMEM
 404 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 405 #endif
 406         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 407 #else
 408         max_mapnr = max_low_pfn;
 409 #endif
 410         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 411
 412         maar_init();
 413         free_all_bootmem();
 414         setup_zero_pages();     /* Setup zeroed pages.  */
 415         mem_init_free_highmem();
 416         mem_init_print_info(NULL);
 417
 418 #ifdef CONFIG_64BIT
 419         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 420                 /* The -4 is a hack so that user tools don't have to handle
 421                    the overflow.  */
 422                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 423                                 0x80000000 - 4, KCORE_TEXT);
 424 #endif
 425 }
 426 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 427
 428 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 429 {
 430         unsigned long pfn;
 431
 432         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 433                 struct page *page = pfn_to_page(pfn);
 434                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 435
 436                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 437                 free_reserved_page(page);
 438         }
 439         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 440 }
 441
 442 #ifdef CONFIG_BLK_DEV_INITRD
 443 void free_initrd_mem(unsigned long start, unsigned long end)
 444 {
 445         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 446                            "initrd");
 447 }
 448 #endif
 449
 450 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 451
 452 void __init_refok free_initmem(void)
 453 {
 454         prom_free_prom_memory();
 455         /*
 456          * Let the platform define a specific function to free the
 457          * init section since EVA may have used any possible mapping
 458          * between virtual and physical addresses.
 459          */
 460         if (free_init_pages_eva)
 461                 free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 462         else
 463                 free_initmem_default(POISON_FREE_INITMEM);
 464 }
 465
 466 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 467 unsigned long pgd_current[NR_CPUS];
 468 #endif
 469
 470 /*
 471  * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 472  * are constants.  So we use the variants from asm-offset.h until that gcc
 473  * will officially be retired.
 474  *
 475  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 476  * with a single LUI instruction in the TLB handlers.  If we used
 477  * __aligned(64K), its size would get rounded up to the alignment
 478  * size, and waste space.  So we place it in its own section and align
 479  * it in the linker script.
 480  */
 481 pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 482 #ifndef __PAGETABLE_PMD_FOLDED
 483 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 484 #endif
 485 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;