LXR linux/arch/powerpc/mm/pgtable

   1/*
   2 *  This file contains ioremap and related functions for 64-bit machines.
   3 *
   4 *  Derived from arch/ppc64/mm/init.c
   5 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6 *
   7 *  Modifications by Paul Mackerras (PowerMac) (paulus@samba.org)
   8 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
   9 *    Copyright (C) 1996 Paul Mackerras
  10 *
  11 *  Derived from "arch/i386/mm/init.c"
  12 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  13 *
  14 *  Dave Engebretsen <engebret@us.ibm.com>
  15 *      Rework for PPC64 port.
  16 *
  17 *  This program is free software; you can redistribute it and/or
  18 *  modify it under the terms of the GNU General Public License
  19 *  as published by the Free Software Foundation; either version
  20 *  2 of the License, or (at your option) any later version.
  21 *
  22 */
  23
  24#include <linux/signal.h>
  25#include <linux/sched.h>
  26#include <linux/kernel.h>
  27#include <linux/errno.h>
  28#include <linux/string.h>
  29#include <linux/export.h>
  30#include <linux/types.h>
  31#include <linux/mman.h>
  32#include <linux/mm.h>
  33#include <linux/swap.h>
  34#include <linux/stddef.h>
  35#include <linux/vmalloc.h>
  36#include <linux/memblock.h>
  37#include <linux/slab.h>
  38#include <linux/hugetlb.h>
  39
  40#include <asm/pgalloc.h>
  41#include <asm/page.h>
  42#include <asm/prom.h>
  43#include <asm/io.h>
  44#include <asm/mmu_context.h>
  45#include <asm/pgtable.h>
  46#include <asm/mmu.h>
  47#include <asm/smp.h>
  48#include <asm/machdep.h>
  49#include <asm/tlb.h>
  50#include <asm/processor.h>
  51#include <asm/cputable.h>
  52#include <asm/sections.h>
  53#include <asm/firmware.h>
  54#include <asm/dma.h>
  55
  56#include "mmu_decl.h"
  57
  58#ifdef CONFIG_PPC_STD_MMU_64
  59#if TASK_SIZE_USER64 > (1UL << (ESID_BITS + SID_SHIFT))
  60#error TASK_SIZE_USER64 exceeds user VSID range
  61#endif
  62#endif
  63
  64#ifdef CONFIG_PPC_BOOK3S_64
  65/*
  66 * partition table and process table for ISA 3.0
  67 */
  68struct prtb_entry *process_tb;
  69struct patb_entry *partition_tb;
  70/*
  71 * page table size
  72 */
  73unsigned long __pte_index_size;
  74EXPORT_SYMBOL(__pte_index_size);
  75unsigned long __pmd_index_size;
  76EXPORT_SYMBOL(__pmd_index_size);
  77unsigned long __pud_index_size;
  78EXPORT_SYMBOL(__pud_index_size);
  79unsigned long __pgd_index_size;
  80EXPORT_SYMBOL(__pgd_index_size);
  81unsigned long __pmd_cache_index;
  82EXPORT_SYMBOL(__pmd_cache_index);
  83unsigned long __pte_table_size;
  84EXPORT_SYMBOL(__pte_table_size);
  85unsigned long __pmd_table_size;
  86EXPORT_SYMBOL(__pmd_table_size);
  87unsigned long __pud_table_size;
  88EXPORT_SYMBOL(__pud_table_size);
  89unsigned long __pgd_table_size;
  90EXPORT_SYMBOL(__pgd_table_size);
  91unsigned long __pmd_val_bits;
  92EXPORT_SYMBOL(__pmd_val_bits);
  93unsigned long __pud_val_bits;
  94EXPORT_SYMBOL(__pud_val_bits);
  95unsigned long __pgd_val_bits;
  96EXPORT_SYMBOL(__pgd_val_bits);
  97unsigned long __kernel_virt_start;
  98EXPORT_SYMBOL(__kernel_virt_start);
  99unsigned long __kernel_virt_size;
 100EXPORT_SYMBOL(__kernel_virt_size);
 101unsigned long __vmalloc_start;
 102EXPORT_SYMBOL(__vmalloc_start);
 103unsigned long __vmalloc_end;
 104EXPORT_SYMBOL(__vmalloc_end);
 105struct page *vmemmap;
 106EXPORT_SYMBOL(vmemmap);
 107unsigned long __pte_frag_nr;
 108EXPORT_SYMBOL(__pte_frag_nr);
 109unsigned long __pte_frag_size_shift;
 110EXPORT_SYMBOL(__pte_frag_size_shift);
 111unsigned long ioremap_bot;
 112#else /* !CONFIG_PPC_BOOK3S_64 */
 113unsigned long ioremap_bot = IOREMAP_BASE;
 114#endif
 115
 116/**
 117 * __ioremap_at - Low level function to establish the page tables
 118 *                for an IO mapping
 119 */
 120void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
 121                            unsigned long flags)
 122{
 123        unsigned long i;
 124
 125        /* Make sure we have the base flags */
 126        if ((flags & _PAGE_PRESENT) == 0)
 127                flags |= pgprot_val(PAGE_KERNEL);
 128
 129        /* We don't support the 4K PFN hack with ioremap */
 130        if (flags & H_PAGE_4K_PFN)
 131                return NULL;
 132
 133        WARN_ON(pa & ~PAGE_MASK);
 134        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 135        WARN_ON(size & ~PAGE_MASK);
 136
 137        for (i = 0; i < size; i += PAGE_SIZE)
 138                if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
 139                        return NULL;
 140
 141        return (void __iomem *)ea;
 142}
 143
 144/**
 145 * __iounmap_from - Low level function to tear down the page tables
 146 *                  for an IO mapping. This is used for mappings that
 147 *                  are manipulated manually, like partial unmapping of
 148 *                  PCI IOs or ISA space.
 149 */
 150void __iounmap_at(void *ea, unsigned long size)
 151{
 152        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 153        WARN_ON(size & ~PAGE_MASK);
 154
 155        unmap_kernel_range((unsigned long)ea, size);
 156}
 157
 158void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
 159                                unsigned long flags, void *caller)
 160{
 161        phys_addr_t paligned;
 162        void __iomem *ret;
 163
 164        /*
 165         * Choose an address to map it to.
 166         * Once the imalloc system is running, we use it.
 167         * Before that, we map using addresses going
 168         * up from ioremap_bot.  imalloc will use
 169         * the addresses from ioremap_bot through
 170         * IMALLOC_END
 171         * 
 172         */
 173        paligned = addr & PAGE_MASK;
 174        size = PAGE_ALIGN(addr + size) - paligned;
 175
 176        if ((size == 0) || (paligned == 0))
 177                return NULL;
 178
 179        if (slab_is_available()) {
 180                struct vm_struct *area;
 181
 182                area = __get_vm_area_caller(size, VM_IOREMAP,
 183                                            ioremap_bot, IOREMAP_END,
 184                                            caller);
 185                if (area == NULL)
 186                        return NULL;
 187
 188                area->phys_addr = paligned;
 189                ret = __ioremap_at(paligned, area->addr, size, flags);
 190                if (!ret)
 191                        vunmap(area->addr);
 192        } else {
 193                ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
 194                if (ret)
 195                        ioremap_bot += size;
 196        }
 197
 198        if (ret)
 199                ret += addr & ~PAGE_MASK;
 200        return ret;
 201}
 202
 203void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
 204                         unsigned long flags)
 205{
 206        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 207}
 208
 209void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 210{
 211        unsigned long flags = pgprot_val(pgprot_noncached(__pgprot(0)));
 212        void *caller = __builtin_return_address(0);
 213
 214        if (ppc_md.ioremap)
 215                return ppc_md.ioremap(addr, size, flags, caller);
 216        return __ioremap_caller(addr, size, flags, caller);
 217}
 218
 219void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
 220{
 221        unsigned long flags = pgprot_val(pgprot_noncached_wc(__pgprot(0)));
 222        void *caller = __builtin_return_address(0);
 223
 224        if (ppc_md.ioremap)
 225                return ppc_md.ioremap(addr, size, flags, caller);
 226        return __ioremap_caller(addr, size, flags, caller);
 227}
 228
 229void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
 230                             unsigned long flags)
 231{
 232        void *caller = __builtin_return_address(0);
 233
 234        /* writeable implies dirty for kernel addresses */
 235        if (flags & _PAGE_WRITE)
 236                flags |= _PAGE_DIRTY;
 237
 238        /* we don't want to let _PAGE_EXEC leak out */
 239        flags &= ~_PAGE_EXEC;
 240        /*
 241         * Force kernel mapping.
 242         */
 243#if defined(CONFIG_PPC_BOOK3S_64)
 244        flags |= _PAGE_PRIVILEGED;
 245#else
 246        flags &= ~_PAGE_USER;
 247#endif
 248
 249
 250#ifdef _PAGE_BAP_SR
 251        /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
 252         * which means that we just cleared supervisor access... oops ;-) This
 253         * restores it
 254         */
 255        flags |= _PAGE_BAP_SR;
 256#endif
 257
 258        if (ppc_md.ioremap)
 259                return ppc_md.ioremap(addr, size, flags, caller);
 260        return __ioremap_caller(addr, size, flags, caller);
 261}
 262
 263
 264/*  
 265 * Unmap an IO region and remove it from imalloc'd list.
 266 * Access to IO memory should be serialized by driver.
 267 */
 268void __iounmap(volatile void __iomem *token)
 269{
 270        void *addr;
 271
 272        if (!slab_is_available())
 273                return;
 274        
 275        addr = (void *) ((unsigned long __force)
 276                         PCI_FIX_ADDR(token) & PAGE_MASK);
 277        if ((unsigned long)addr < ioremap_bot) {
 278                printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
 279                       " at 0x%p\n", addr);
 280                return;
 281        }
 282        vunmap(addr);
 283}
 284
 285void iounmap(volatile void __iomem *token)
 286{
 287        if (ppc_md.iounmap)
 288                ppc_md.iounmap(token);
 289        else
 290                __iounmap(token);
 291}
 292
 293EXPORT_SYMBOL(ioremap);
 294EXPORT_SYMBOL(ioremap_wc);
 295EXPORT_SYMBOL(ioremap_prot);
 296EXPORT_SYMBOL(__ioremap);
 297EXPORT_SYMBOL(__ioremap_at);
 298EXPORT_SYMBOL(iounmap);
 299EXPORT_SYMBOL(__iounmap);
 300EXPORT_SYMBOL(__iounmap_at);
 301
 302#ifndef __PAGETABLE_PUD_FOLDED
 303/* 4 level page table */
 304struct page *pgd_page(pgd_t pgd)
 305{
 306        if (pgd_huge(pgd))
 307                return pte_page(pgd_pte(pgd));
 308        return virt_to_page(pgd_page_vaddr(pgd));
 309}
 310#endif
 311
 312struct page *pud_page(pud_t pud)
 313{
 314        if (pud_huge(pud))
 315                return pte_page(pud_pte(pud));
 316        return virt_to_page(pud_page_vaddr(pud));
 317}
 318
 319/*
 320 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
 321 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
 322 */
 323struct page *pmd_page(pmd_t pmd)
 324{
 325        if (pmd_trans_huge(pmd) || pmd_huge(pmd))
 326                return pte_page(pmd_pte(pmd));
 327        return virt_to_page(pmd_page_vaddr(pmd));
 328}
 329
 330#ifdef CONFIG_PPC_64K_PAGES
 331static pte_t *get_from_cache(struct mm_struct *mm)
 332{
 333        void *pte_frag, *ret;
 334
 335        spin_lock(&mm->page_table_lock);
 336        ret = mm->context.pte_frag;
 337        if (ret) {
 338                pte_frag = ret + PTE_FRAG_SIZE;
 339                /*
 340                 * If we have taken up all the fragments mark PTE page NULL
 341                 */
 342                if (((unsigned long)pte_frag & ~PAGE_MASK) == 0)
 343                        pte_frag = NULL;
 344                mm->context.pte_frag = pte_frag;
 345        }
 346        spin_unlock(&mm->page_table_lock);
 347        return (pte_t *)ret;
 348}
 349
 350static pte_t *__alloc_for_cache(struct mm_struct *mm, int kernel)
 351{
 352        void *ret = NULL;
 353        struct page *page = alloc_page(GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO);
 354        if (!page)
 355                return NULL;
 356        if (!kernel && !pgtable_page_ctor(page)) {
 357                __free_page(page);
 358                return NULL;
 359        }
 360
 361        ret = page_address(page);
 362        spin_lock(&mm->page_table_lock);
 363        /*
 364         * If we find pgtable_page set, we return
 365         * the allocated page with single fragement
 366         * count.
 367         */
 368        if (likely(!mm->context.pte_frag)) {
 369                set_page_count(page, PTE_FRAG_NR);
 370                mm->context.pte_frag = ret + PTE_FRAG_SIZE;
 371        }
 372        spin_unlock(&mm->page_table_lock);
 373
 374        return (pte_t *)ret;
 375}
 376
 377pte_t *pte_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr, int kernel)
 378{
 379        pte_t *pte;
 380
 381        pte = get_from_cache(mm);
 382        if (pte)
 383                return pte;
 384
 385        return __alloc_for_cache(mm, kernel);
 386}
 387#endif /* CONFIG_PPC_64K_PAGES */
 388
 389void pte_fragment_free(unsigned long *table, int kernel)
 390{
 391        struct page *page = virt_to_page(table);
 392        if (put_page_testzero(page)) {
 393                if (!kernel)
 394                        pgtable_page_dtor(page);
 395                free_hot_cold_page(page, 0);
 396        }
 397}
 398
 399#ifdef CONFIG_SMP
 400void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 401{
 402        unsigned long pgf = (unsigned long)table;
 403
 404        BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 405        pgf |= shift;
 406        tlb_remove_table(tlb, (void *)pgf);
 407}
 408
 409void __tlb_remove_table(void *_table)
 410{
 411        void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
 412        unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
 413
 414        if (!shift)
 415                /* PTE page needs special handling */
 416                pte_fragment_free(table, 0);
 417        else {
 418                BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 419                kmem_cache_free(PGT_CACHE(shift), table);
 420        }
 421}
 422#else
 423void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 424{
 425        if (!shift) {
 426                /* PTE page needs special handling */
 427                pte_fragment_free(table, 0);
 428        } else {
 429                BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE);
 430                kmem_cache_free(PGT_CACHE(shift), table);
 431        }
 432}
 433#endif
 434