linux/arch/powerpc/mm/pgtable_32.c
<<
>>
Prefs
   1/*
   2 * This file contains the routines setting up the linux page tables.
   3 *  -- paulus
   4 *
   5 *  Derived from arch/ppc/mm/init.c:
   6 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   7 *
   8 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
   9 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
  10 *    Copyright (C) 1996 Paul Mackerras
  11 *
  12 *  Derived from "arch/i386/mm/init.c"
  13 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  14 *
  15 *  This program is free software; you can redistribute it and/or
  16 *  modify it under the terms of the GNU General Public License
  17 *  as published by the Free Software Foundation; either version
  18 *  2 of the License, or (at your option) any later version.
  19 *
  20 */
  21
  22#include <linux/kernel.h>
  23#include <linux/module.h>
  24#include <linux/types.h>
  25#include <linux/mm.h>
  26#include <linux/vmalloc.h>
  27#include <linux/init.h>
  28#include <linux/highmem.h>
  29#include <linux/memblock.h>
  30#include <linux/slab.h>
  31
  32#include <asm/pgtable.h>
  33#include <asm/pgalloc.h>
  34#include <asm/fixmap.h>
  35#include <asm/io.h>
  36
  37#include "mmu_decl.h"
  38
  39unsigned long ioremap_base;
  40unsigned long ioremap_bot;
  41EXPORT_SYMBOL(ioremap_bot);     /* aka VMALLOC_END */
  42
  43#if defined(CONFIG_6xx) || defined(CONFIG_POWER3)
  44#define HAVE_BATS       1
  45#endif
  46
  47#if defined(CONFIG_FSL_BOOKE)
  48#define HAVE_TLBCAM     1
  49#endif
  50
  51extern char etext[], _stext[];
  52
  53#ifdef HAVE_BATS
  54extern phys_addr_t v_mapped_by_bats(unsigned long va);
  55extern unsigned long p_mapped_by_bats(phys_addr_t pa);
  56void setbat(int index, unsigned long virt, phys_addr_t phys,
  57            unsigned int size, int flags);
  58
  59#else /* !HAVE_BATS */
  60#define v_mapped_by_bats(x)     (0UL)
  61#define p_mapped_by_bats(x)     (0UL)
  62#endif /* HAVE_BATS */
  63
  64#ifdef HAVE_TLBCAM
  65extern unsigned int tlbcam_index;
  66extern phys_addr_t v_mapped_by_tlbcam(unsigned long va);
  67extern unsigned long p_mapped_by_tlbcam(phys_addr_t pa);
  68#else /* !HAVE_TLBCAM */
  69#define v_mapped_by_tlbcam(x)   (0UL)
  70#define p_mapped_by_tlbcam(x)   (0UL)
  71#endif /* HAVE_TLBCAM */
  72
  73#define PGDIR_ORDER     (32 + PGD_T_LOG2 - PGDIR_SHIFT)
  74
  75pgd_t *pgd_alloc(struct mm_struct *mm)
  76{
  77        pgd_t *ret;
  78
  79        /* pgdir take page or two with 4K pages and a page fraction otherwise */
  80#ifndef CONFIG_PPC_4K_PAGES
  81        ret = kzalloc(1 << PGDIR_ORDER, GFP_KERNEL);
  82#else
  83        ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
  84                        PGDIR_ORDER - PAGE_SHIFT);
  85#endif
  86        return ret;
  87}
  88
  89void pgd_free(struct mm_struct *mm, pgd_t *pgd)
  90{
  91#ifndef CONFIG_PPC_4K_PAGES
  92        kfree((void *)pgd);
  93#else
  94        free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT);
  95#endif
  96}
  97
  98__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
  99{
 100        pte_t *pte;
 101        extern int mem_init_done;
 102        extern void *early_get_page(void);
 103
 104        if (mem_init_done) {
 105                pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
 106        } else {
 107                pte = (pte_t *)early_get_page();
 108                if (pte)
 109                        clear_page(pte);
 110        }
 111        return pte;
 112}
 113
 114pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
 115{
 116        struct page *ptepage;
 117
 118        gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO;
 119
 120        ptepage = alloc_pages(flags, 0);
 121        if (!ptepage)
 122                return NULL;
 123        pgtable_page_ctor(ptepage);
 124        return ptepage;
 125}
 126
 127void __iomem *
 128ioremap(phys_addr_t addr, unsigned long size)
 129{
 130        return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED,
 131                                __builtin_return_address(0));
 132}
 133EXPORT_SYMBOL(ioremap);
 134
 135void __iomem *
 136ioremap_wc(phys_addr_t addr, unsigned long size)
 137{
 138        return __ioremap_caller(addr, size, _PAGE_NO_CACHE,
 139                                __builtin_return_address(0));
 140}
 141EXPORT_SYMBOL(ioremap_wc);
 142
 143void __iomem *
 144ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
 145{
 146        /* writeable implies dirty for kernel addresses */
 147        if (flags & _PAGE_RW)
 148                flags |= _PAGE_DIRTY | _PAGE_HWWRITE;
 149
 150        /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
 151        flags &= ~(_PAGE_USER | _PAGE_EXEC);
 152
 153#ifdef _PAGE_BAP_SR
 154        /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
 155         * which means that we just cleared supervisor access... oops ;-) This
 156         * restores it
 157         */
 158        flags |= _PAGE_BAP_SR;
 159#endif
 160
 161        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 162}
 163EXPORT_SYMBOL(ioremap_prot);
 164
 165void __iomem *
 166__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
 167{
 168        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 169}
 170
 171void __iomem *
 172__ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
 173                 void *caller)
 174{
 175        unsigned long v, i;
 176        phys_addr_t p;
 177        int err;
 178
 179        /* Make sure we have the base flags */
 180        if ((flags & _PAGE_PRESENT) == 0)
 181                flags |= PAGE_KERNEL;
 182
 183        /* Non-cacheable page cannot be coherent */
 184        if (flags & _PAGE_NO_CACHE)
 185                flags &= ~_PAGE_COHERENT;
 186
 187        /*
 188         * Choose an address to map it to.
 189         * Once the vmalloc system is running, we use it.
 190         * Before then, we use space going down from ioremap_base
 191         * (ioremap_bot records where we're up to).
 192         */
 193        p = addr & PAGE_MASK;
 194        size = PAGE_ALIGN(addr + size) - p;
 195
 196        /*
 197         * If the address lies within the first 16 MB, assume it's in ISA
 198         * memory space
 199         */
 200        if (p < 16*1024*1024)
 201                p += _ISA_MEM_BASE;
 202
 203#ifndef CONFIG_CRASH_DUMP
 204        /*
 205         * Don't allow anybody to remap normal RAM that we're using.
 206         * mem_init() sets high_memory so only do the check after that.
 207         */
 208        if (mem_init_done && (p < virt_to_phys(high_memory)) &&
 209            !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
 210                printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n",
 211                       (unsigned long long)p, __builtin_return_address(0));
 212                return NULL;
 213        }
 214#endif
 215
 216        if (size == 0)
 217                return NULL;
 218
 219        /*
 220         * Is it already mapped?  Perhaps overlapped by a previous
 221         * BAT mapping.  If the whole area is mapped then we're done,
 222         * otherwise remap it since we want to keep the virt addrs for
 223         * each request contiguous.
 224         *
 225         * We make the assumption here that if the bottom and top
 226         * of the range we want are mapped then it's mapped to the
 227         * same virt address (and this is contiguous).
 228         *  -- Cort
 229         */
 230        if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ )
 231                goto out;
 232
 233        if ((v = p_mapped_by_tlbcam(p)))
 234                goto out;
 235
 236        if (mem_init_done) {
 237                struct vm_struct *area;
 238                area = get_vm_area_caller(size, VM_IOREMAP, caller);
 239                if (area == 0)
 240                        return NULL;
 241                area->phys_addr = p;
 242                v = (unsigned long) area->addr;
 243        } else {
 244                v = (ioremap_bot -= size);
 245        }
 246
 247        /*
 248         * Should check if it is a candidate for a BAT mapping
 249         */
 250
 251        err = 0;
 252        for (i = 0; i < size && err == 0; i += PAGE_SIZE)
 253                err = map_page(v+i, p+i, flags);
 254        if (err) {
 255                if (mem_init_done)
 256                        vunmap((void *)v);
 257                return NULL;
 258        }
 259
 260out:
 261        return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
 262}
 263EXPORT_SYMBOL(__ioremap);
 264
 265void iounmap(volatile void __iomem *addr)
 266{
 267        /*
 268         * If mapped by BATs then there is nothing to do.
 269         * Calling vfree() generates a benign warning.
 270         */
 271        if (v_mapped_by_bats((unsigned long)addr)) return;
 272
 273        if (addr > high_memory && (unsigned long) addr < ioremap_bot)
 274                vunmap((void *) (PAGE_MASK & (unsigned long)addr));
 275}
 276EXPORT_SYMBOL(iounmap);
 277
 278int map_page(unsigned long va, phys_addr_t pa, int flags)
 279{
 280        pmd_t *pd;
 281        pte_t *pg;
 282        int err = -ENOMEM;
 283
 284        /* Use upper 10 bits of VA to index the first level map */
 285        pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
 286        /* Use middle 10 bits of VA to index the second-level map */
 287        pg = pte_alloc_kernel(pd, va);
 288        if (pg != 0) {
 289                err = 0;
 290                /* The PTE should never be already set nor present in the
 291                 * hash table
 292                 */
 293                BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) &&
 294                       flags);
 295                set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
 296                                                     __pgprot(flags)));
 297        }
 298        return err;
 299}
 300
 301/*
 302 * Map in a chunk of physical memory starting at start.
 303 */
 304void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
 305{
 306        unsigned long v, s, f;
 307        phys_addr_t p;
 308        int ktext;
 309
 310        s = offset;
 311        v = PAGE_OFFSET + s;
 312        p = memstart_addr + s;
 313        for (; s < top; s += PAGE_SIZE) {
 314                ktext = ((char *) v >= _stext && (char *) v < etext);
 315                f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL;
 316                map_page(v, p, f);
 317#ifdef CONFIG_PPC_STD_MMU_32
 318                if (ktext)
 319                        hash_preload(&init_mm, v, 0, 0x300);
 320#endif
 321                v += PAGE_SIZE;
 322                p += PAGE_SIZE;
 323        }
 324}
 325
 326void __init mapin_ram(void)
 327{
 328        unsigned long s, top;
 329
 330#ifndef CONFIG_WII
 331        top = total_lowmem;
 332        s = mmu_mapin_ram(top);
 333        __mapin_ram_chunk(s, top);
 334#else
 335        if (!wii_hole_size) {
 336                s = mmu_mapin_ram(total_lowmem);
 337                __mapin_ram_chunk(s, total_lowmem);
 338        } else {
 339                top = wii_hole_start;
 340                s = mmu_mapin_ram(top);
 341                __mapin_ram_chunk(s, top);
 342
 343                top = memblock_end_of_DRAM();
 344                s = wii_mmu_mapin_mem2(top);
 345                __mapin_ram_chunk(s, top);
 346        }
 347#endif
 348}
 349
 350/* Scan the real Linux page tables and return a PTE pointer for
 351 * a virtual address in a context.
 352 * Returns true (1) if PTE was found, zero otherwise.  The pointer to
 353 * the PTE pointer is unmodified if PTE is not found.
 354 */
 355int
 356get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
 357{
 358        pgd_t   *pgd;
 359        pud_t   *pud;
 360        pmd_t   *pmd;
 361        pte_t   *pte;
 362        int     retval = 0;
 363
 364        pgd = pgd_offset(mm, addr & PAGE_MASK);
 365        if (pgd) {
 366                pud = pud_offset(pgd, addr & PAGE_MASK);
 367                if (pud && pud_present(*pud)) {
 368                        pmd = pmd_offset(pud, addr & PAGE_MASK);
 369                        if (pmd_present(*pmd)) {
 370                                pte = pte_offset_map(pmd, addr & PAGE_MASK);
 371                                if (pte) {
 372                                        retval = 1;
 373                                        *ptep = pte;
 374                                        if (pmdp)
 375                                                *pmdp = pmd;
 376                                        /* XXX caller needs to do pte_unmap, yuck */
 377                                }
 378                        }
 379                }
 380        }
 381        return(retval);
 382}
 383
 384#ifdef CONFIG_DEBUG_PAGEALLOC
 385
 386static int __change_page_attr(struct page *page, pgprot_t prot)
 387{
 388        pte_t *kpte;
 389        pmd_t *kpmd;
 390        unsigned long address;
 391
 392        BUG_ON(PageHighMem(page));
 393        address = (unsigned long)page_address(page);
 394
 395        if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address))
 396                return 0;
 397        if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
 398                return -EINVAL;
 399        __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
 400        wmb();
 401        flush_tlb_page(NULL, address);
 402        pte_unmap(kpte);
 403
 404        return 0;
 405}
 406
 407/*
 408 * Change the page attributes of an page in the linear mapping.
 409 *
 410 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
 411 */
 412static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
 413{
 414        int i, err = 0;
 415        unsigned long flags;
 416
 417        local_irq_save(flags);
 418        for (i = 0; i < numpages; i++, page++) {
 419                err = __change_page_attr(page, prot);
 420                if (err)
 421                        break;
 422        }
 423        local_irq_restore(flags);
 424        return err;
 425}
 426
 427
 428void kernel_map_pages(struct page *page, int numpages, int enable)
 429{
 430        if (PageHighMem(page))
 431                return;
 432
 433        change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
 434}
 435#endif /* CONFIG_DEBUG_PAGEALLOC */
 436
 437static int fixmaps;
 438
 439void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
 440{
 441        unsigned long address = __fix_to_virt(idx);
 442
 443        if (idx >= __end_of_fixed_addresses) {
 444                BUG();
 445                return;
 446        }
 447
 448        map_page(address, phys, pgprot_val(flags));
 449        fixmaps++;
 450}
 451
 452void __this_fixmap_does_not_exist(void)
 453{
 454        WARN_ON(1);
 455}
 456