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/slab.h>
  37#include <linux/hugetlb.h>
  38
  39#include <asm/pgalloc.h>
  40#include <asm/page.h>
  41#include <asm/prom.h>
  42#include <asm/io.h>
  43#include <asm/mmu_context.h>
  44#include <asm/pgtable.h>
  45#include <asm/mmu.h>
  46#include <asm/smp.h>
  47#include <asm/machdep.h>
  48#include <asm/tlb.h>
  49#include <asm/processor.h>
  50#include <asm/cputable.h>
  51#include <asm/sections.h>
  52#include <asm/firmware.h>
  53#include <asm/dma.h>
  54
  55#include "mmu_decl.h"
  56
  57
  58#ifdef CONFIG_PPC_BOOK3S_64
  59/*
  60 * partition table and process table for ISA 3.0
  61 */
  62struct prtb_entry *process_tb;
  63struct patb_entry *partition_tb;
  64/*
  65 * page table size
  66 */
  67unsigned long __pte_index_size;
  68EXPORT_SYMBOL(__pte_index_size);
  69unsigned long __pmd_index_size;
  70EXPORT_SYMBOL(__pmd_index_size);
  71unsigned long __pud_index_size;
  72EXPORT_SYMBOL(__pud_index_size);
  73unsigned long __pgd_index_size;
  74EXPORT_SYMBOL(__pgd_index_size);
  75unsigned long __pud_cache_index;
  76EXPORT_SYMBOL(__pud_cache_index);
  77unsigned long __pte_table_size;
  78EXPORT_SYMBOL(__pte_table_size);
  79unsigned long __pmd_table_size;
  80EXPORT_SYMBOL(__pmd_table_size);
  81unsigned long __pud_table_size;
  82EXPORT_SYMBOL(__pud_table_size);
  83unsigned long __pgd_table_size;
  84EXPORT_SYMBOL(__pgd_table_size);
  85unsigned long __pmd_val_bits;
  86EXPORT_SYMBOL(__pmd_val_bits);
  87unsigned long __pud_val_bits;
  88EXPORT_SYMBOL(__pud_val_bits);
  89unsigned long __pgd_val_bits;
  90EXPORT_SYMBOL(__pgd_val_bits);
  91unsigned long __kernel_virt_start;
  92EXPORT_SYMBOL(__kernel_virt_start);
  93unsigned long __kernel_virt_size;
  94EXPORT_SYMBOL(__kernel_virt_size);
  95unsigned long __vmalloc_start;
  96EXPORT_SYMBOL(__vmalloc_start);
  97unsigned long __vmalloc_end;
  98EXPORT_SYMBOL(__vmalloc_end);
  99unsigned long __kernel_io_start;
 100EXPORT_SYMBOL(__kernel_io_start);
 101struct page *vmemmap;
 102EXPORT_SYMBOL(vmemmap);
 103unsigned long __pte_frag_nr;
 104EXPORT_SYMBOL(__pte_frag_nr);
 105unsigned long __pte_frag_size_shift;
 106EXPORT_SYMBOL(__pte_frag_size_shift);
 107unsigned long ioremap_bot;
 108#else /* !CONFIG_PPC_BOOK3S_64 */
 109unsigned long ioremap_bot = IOREMAP_BASE;
 110#endif
 111
 112/**
 113 * __ioremap_at - Low level function to establish the page tables
 114 *                for an IO mapping
 115 */
 116void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
 117                            unsigned long flags)
 118{
 119        unsigned long i;
 120
 121        /* Make sure we have the base flags */
 122        if ((flags & _PAGE_PRESENT) == 0)
 123                flags |= pgprot_val(PAGE_KERNEL);
 124
 125        /* We don't support the 4K PFN hack with ioremap */
 126        if (flags & H_PAGE_4K_PFN)
 127                return NULL;
 128
 129        WARN_ON(pa & ~PAGE_MASK);
 130        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 131        WARN_ON(size & ~PAGE_MASK);
 132
 133        for (i = 0; i < size; i += PAGE_SIZE)
 134                if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
 135                        return NULL;
 136
 137        return (void __iomem *)ea;
 138}
 139
 140/**
 141 * __iounmap_from - Low level function to tear down the page tables
 142 *                  for an IO mapping. This is used for mappings that
 143 *                  are manipulated manually, like partial unmapping of
 144 *                  PCI IOs or ISA space.
 145 */
 146void __iounmap_at(void *ea, unsigned long size)
 147{
 148        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 149        WARN_ON(size & ~PAGE_MASK);
 150
 151        unmap_kernel_range((unsigned long)ea, size);
 152}
 153
 154void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
 155                                unsigned long flags, void *caller)
 156{
 157        phys_addr_t paligned;
 158        void __iomem *ret;
 159
 160        /*
 161         * Choose an address to map it to.
 162         * Once the imalloc system is running, we use it.
 163         * Before that, we map using addresses going
 164         * up from ioremap_bot.  imalloc will use
 165         * the addresses from ioremap_bot through
 166         * IMALLOC_END
 167         * 
 168         */
 169        paligned = addr & PAGE_MASK;
 170        size = PAGE_ALIGN(addr + size) - paligned;
 171
 172        if ((size == 0) || (paligned == 0))
 173                return NULL;
 174
 175        if (slab_is_available()) {
 176                struct vm_struct *area;
 177
 178                area = __get_vm_area_caller(size, VM_IOREMAP,
 179                                            ioremap_bot, IOREMAP_END,
 180                                            caller);
 181                if (area == NULL)
 182                        return NULL;
 183
 184                area->phys_addr = paligned;
 185                ret = __ioremap_at(paligned, area->addr, size, flags);
 186                if (!ret)
 187                        vunmap(area->addr);
 188        } else {
 189                ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
 190                if (ret)
 191                        ioremap_bot += size;
 192        }
 193
 194        if (ret)
 195                ret += addr & ~PAGE_MASK;
 196        return ret;
 197}
 198
 199void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
 200                         unsigned long flags)
 201{
 202        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 203}
 204
 205void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 206{
 207        unsigned long flags = pgprot_val(pgprot_noncached(__pgprot(0)));
 208        void *caller = __builtin_return_address(0);
 209
 210        if (ppc_md.ioremap)
 211                return ppc_md.ioremap(addr, size, flags, caller);
 212        return __ioremap_caller(addr, size, flags, caller);
 213}
 214
 215void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
 216{
 217        unsigned long flags = pgprot_val(pgprot_noncached_wc(__pgprot(0)));
 218        void *caller = __builtin_return_address(0);
 219
 220        if (ppc_md.ioremap)
 221                return ppc_md.ioremap(addr, size, flags, caller);
 222        return __ioremap_caller(addr, size, flags, caller);
 223}
 224
 225void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
 226                             unsigned long flags)
 227{
 228        void *caller = __builtin_return_address(0);
 229
 230        /* writeable implies dirty for kernel addresses */
 231        if (flags & _PAGE_WRITE)
 232                flags |= _PAGE_DIRTY;
 233
 234        /* we don't want to let _PAGE_EXEC leak out */
 235        flags &= ~_PAGE_EXEC;
 236        /*
 237         * Force kernel mapping.
 238         */
 239        flags &= ~_PAGE_USER;
 240        flags |= _PAGE_PRIVILEGED;
 241
 242        if (ppc_md.ioremap)
 243                return ppc_md.ioremap(addr, size, flags, caller);
 244        return __ioremap_caller(addr, size, flags, caller);
 245}
 246
 247
 248/*  
 249 * Unmap an IO region and remove it from imalloc'd list.
 250 * Access to IO memory should be serialized by driver.
 251 */
 252void __iounmap(volatile void __iomem *token)
 253{
 254        void *addr;
 255
 256        if (!slab_is_available())
 257                return;
 258        
 259        addr = (void *) ((unsigned long __force)
 260                         PCI_FIX_ADDR(token) & PAGE_MASK);
 261        if ((unsigned long)addr < ioremap_bot) {
 262                printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
 263                       " at 0x%p\n", addr);
 264                return;
 265        }
 266        vunmap(addr);
 267}
 268
 269void iounmap(volatile void __iomem *token)
 270{
 271        if (ppc_md.iounmap)
 272                ppc_md.iounmap(token);
 273        else
 274                __iounmap(token);
 275}
 276
 277EXPORT_SYMBOL(ioremap);
 278EXPORT_SYMBOL(ioremap_wc);
 279EXPORT_SYMBOL(ioremap_prot);
 280EXPORT_SYMBOL(__ioremap);
 281EXPORT_SYMBOL(__ioremap_at);
 282EXPORT_SYMBOL(iounmap);
 283EXPORT_SYMBOL(__iounmap);
 284EXPORT_SYMBOL(__iounmap_at);
 285
 286#ifndef __PAGETABLE_PUD_FOLDED
 287/* 4 level page table */
 288struct page *pgd_page(pgd_t pgd)
 289{
 290        if (pgd_huge(pgd))
 291                return pte_page(pgd_pte(pgd));
 292        return virt_to_page(pgd_page_vaddr(pgd));
 293}
 294#endif
 295
 296struct page *pud_page(pud_t pud)
 297{
 298        if (pud_huge(pud))
 299                return pte_page(pud_pte(pud));
 300        return virt_to_page(pud_page_vaddr(pud));
 301}
 302
 303/*
 304 * For hugepage we have pfn in the pmd, we use PTE_RPN_SHIFT bits for flags
 305 * For PTE page, we have a PTE_FRAG_SIZE (4K) aligned virtual address.
 306 */
 307struct page *pmd_page(pmd_t pmd)
 308{
 309        if (pmd_trans_huge(pmd) || pmd_huge(pmd) || pmd_devmap(pmd))
 310                return pte_page(pmd_pte(pmd));
 311        return virt_to_page(pmd_page_vaddr(pmd));
 312}
 313
 314#ifdef CONFIG_STRICT_KERNEL_RWX
 315void mark_rodata_ro(void)
 316{
 317        if (!mmu_has_feature(MMU_FTR_KERNEL_RO)) {
 318                pr_warn("Warning: Unable to mark rodata read only on this CPU.\n");
 319                return;
 320        }
 321
 322        if (radix_enabled())
 323                radix__mark_rodata_ro();
 324        else
 325                hash__mark_rodata_ro();
 326}
 327
 328void mark_initmem_nx(void)
 329{
 330        if (radix_enabled())
 331                radix__mark_initmem_nx();
 332        else
 333                hash__mark_initmem_nx();
 334}
 335#endif
 336