linux/arch/mips/mm/init.c
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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/export.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#include <linux/initrd.h>
  34
  35#include <asm/asm-offsets.h>
  36#include <asm/bootinfo.h>
  37#include <asm/cachectl.h>
  38#include <asm/cpu.h>
  39#include <asm/dma.h>
  40#include <asm/kmap_types.h>
  41#include <asm/maar.h>
  42#include <asm/mmu_context.h>
  43#include <asm/sections.h>
  44#include <asm/pgtable.h>
  45#include <asm/pgalloc.h>
  46#include <asm/tlb.h>
  47#include <asm/fixmap.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 */
  56unsigned long empty_zero_page, zero_page_mask;
  57EXPORT_SYMBOL_GPL(empty_zero_page);
  58EXPORT_SYMBOL(zero_page_mask);
  59
  60/*
  61 * Not static inline because used by IP27 special magic initialization code
  62 */
  63void 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
  85static 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 = num_wired_entries();
 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
 133void *kmap_coherent(struct page *page, unsigned long addr)
 134{
 135        return __kmap_pgprot(page, addr, PAGE_KERNEL);
 136}
 137
 138void *kmap_noncoherent(struct page *page, unsigned long addr)
 139{
 140        return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 141}
 142
 143void 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 = num_wired_entries() - 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
 165void 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
 189void 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
 207void 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}
 222EXPORT_SYMBOL_GPL(copy_from_user_page);
 223
 224void __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
 260unsigned __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
 295void 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_VL)) {
 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
 373int 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
 400void __init paging_init(void)
 401{
 402        unsigned long max_zone_pfns[MAX_NR_ZONES];
 403
 404        pagetable_init();
 405
 406#ifdef CONFIG_HIGHMEM
 407        kmap_init();
 408#endif
 409#ifdef CONFIG_ZONE_DMA
 410        max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 411#endif
 412#ifdef CONFIG_ZONE_DMA32
 413        max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 414#endif
 415        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 416#ifdef CONFIG_HIGHMEM
 417        max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 418
 419        if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 420                printk(KERN_WARNING "This processor doesn't support highmem."
 421                       " %ldk highmem ignored\n",
 422                       (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 423                max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 424        }
 425#endif
 426
 427        free_area_init_nodes(max_zone_pfns);
 428}
 429
 430#ifdef CONFIG_64BIT
 431static struct kcore_list kcore_kseg0;
 432#endif
 433
 434static inline void mem_init_free_highmem(void)
 435{
 436#ifdef CONFIG_HIGHMEM
 437        unsigned long tmp;
 438
 439        if (cpu_has_dc_aliases)
 440                return;
 441
 442        for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 443                struct page *page = pfn_to_page(tmp);
 444
 445                if (!page_is_ram(tmp))
 446                        SetPageReserved(page);
 447                else
 448                        free_highmem_page(page);
 449        }
 450#endif
 451}
 452
 453void __init mem_init(void)
 454{
 455#ifdef CONFIG_HIGHMEM
 456#ifdef CONFIG_DISCONTIGMEM
 457#error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 458#endif
 459        max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 460#else
 461        max_mapnr = max_low_pfn;
 462#endif
 463        high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 464
 465        maar_init();
 466        free_all_bootmem();
 467        setup_zero_pages();     /* Setup zeroed pages.  */
 468        mem_init_free_highmem();
 469        mem_init_print_info(NULL);
 470
 471#ifdef CONFIG_64BIT
 472        if ((unsigned long) &_text > (unsigned long) CKSEG0)
 473                /* The -4 is a hack so that user tools don't have to handle
 474                   the overflow.  */
 475                kclist_add(&kcore_kseg0, (void *) CKSEG0,
 476                                0x80000000 - 4, KCORE_TEXT);
 477#endif
 478}
 479#endif /* !CONFIG_NEED_MULTIPLE_NODES */
 480
 481void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 482{
 483        unsigned long pfn;
 484
 485        for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 486                struct page *page = pfn_to_page(pfn);
 487                void *addr = phys_to_virt(PFN_PHYS(pfn));
 488
 489                memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 490                free_reserved_page(page);
 491        }
 492        printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 493}
 494
 495#ifdef CONFIG_BLK_DEV_INITRD
 496void free_initrd_mem(unsigned long start, unsigned long end)
 497{
 498        free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 499                           "initrd");
 500}
 501#endif
 502
 503void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 504
 505void __ref free_initmem(void)
 506{
 507        prom_free_prom_memory();
 508        /*
 509         * Let the platform define a specific function to free the
 510         * init section since EVA may have used any possible mapping
 511         * between virtual and physical addresses.
 512         */
 513        if (free_init_pages_eva)
 514                free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 515        else
 516                free_initmem_default(POISON_FREE_INITMEM);
 517}
 518
 519#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 520unsigned long pgd_current[NR_CPUS];
 521#endif
 522
 523/*
 524 * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 525 * are constants.  So we use the variants from asm-offset.h until that gcc
 526 * will officially be retired.
 527 *
 528 * Align swapper_pg_dir in to 64K, allows its address to be loaded
 529 * with a single LUI instruction in the TLB handlers.  If we used
 530 * __aligned(64K), its size would get rounded up to the alignment
 531 * size, and waste space.  So we place it in its own section and align
 532 * it in the linker script.
 533 */
 534pgd_t swapper_pg_dir[_PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
 535#ifndef __PAGETABLE_PUD_FOLDED
 536pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
 537#endif
 538#ifndef __PAGETABLE_PMD_FOLDED
 539pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 540EXPORT_SYMBOL_GPL(invalid_pmd_table);
 541#endif
 542pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
 543EXPORT_SYMBOL(invalid_pte_table);
 544