linux/arch/powerpc/mm/pgtable_64.c
<<
>>
Prefs
   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/init.h>
  37#include <linux/bootmem.h>
  38#include <linux/memblock.h>
  39#include <linux/slab.h>
  40
  41#include <asm/pgalloc.h>
  42#include <asm/page.h>
  43#include <asm/prom.h>
  44#include <asm/io.h>
  45#include <asm/mmu_context.h>
  46#include <asm/pgtable.h>
  47#include <asm/mmu.h>
  48#include <asm/smp.h>
  49#include <asm/machdep.h>
  50#include <asm/tlb.h>
  51#include <asm/processor.h>
  52#include <asm/cputable.h>
  53#include <asm/sections.h>
  54#include <asm/system.h>
  55#include <asm/abs_addr.h>
  56#include <asm/firmware.h>
  57
  58#include "mmu_decl.h"
  59
  60unsigned long ioremap_bot = IOREMAP_BASE;
  61
  62
  63#ifdef CONFIG_PPC_MMU_NOHASH
  64static void *early_alloc_pgtable(unsigned long size)
  65{
  66        void *pt;
  67
  68        if (init_bootmem_done)
  69                pt = __alloc_bootmem(size, size, __pa(MAX_DMA_ADDRESS));
  70        else
  71                pt = __va(memblock_alloc_base(size, size,
  72                                         __pa(MAX_DMA_ADDRESS)));
  73        memset(pt, 0, size);
  74
  75        return pt;
  76}
  77#endif /* CONFIG_PPC_MMU_NOHASH */
  78
  79/*
  80 * map_kernel_page currently only called by __ioremap
  81 * map_kernel_page adds an entry to the ioremap page table
  82 * and adds an entry to the HPT, possibly bolting it
  83 */
  84int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
  85{
  86        pgd_t *pgdp;
  87        pud_t *pudp;
  88        pmd_t *pmdp;
  89        pte_t *ptep;
  90
  91        if (slab_is_available()) {
  92                pgdp = pgd_offset_k(ea);
  93                pudp = pud_alloc(&init_mm, pgdp, ea);
  94                if (!pudp)
  95                        return -ENOMEM;
  96                pmdp = pmd_alloc(&init_mm, pudp, ea);
  97                if (!pmdp)
  98                        return -ENOMEM;
  99                ptep = pte_alloc_kernel(pmdp, ea);
 100                if (!ptep)
 101                        return -ENOMEM;
 102                set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 103                                                          __pgprot(flags)));
 104        } else {
 105#ifdef CONFIG_PPC_MMU_NOHASH
 106                /* Warning ! This will blow up if bootmem is not initialized
 107                 * which our ppc64 code is keen to do that, we'll need to
 108                 * fix it and/or be more careful
 109                 */
 110                pgdp = pgd_offset_k(ea);
 111#ifdef PUD_TABLE_SIZE
 112                if (pgd_none(*pgdp)) {
 113                        pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
 114                        BUG_ON(pudp == NULL);
 115                        pgd_populate(&init_mm, pgdp, pudp);
 116                }
 117#endif /* PUD_TABLE_SIZE */
 118                pudp = pud_offset(pgdp, ea);
 119                if (pud_none(*pudp)) {
 120                        pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
 121                        BUG_ON(pmdp == NULL);
 122                        pud_populate(&init_mm, pudp, pmdp);
 123                }
 124                pmdp = pmd_offset(pudp, ea);
 125                if (!pmd_present(*pmdp)) {
 126                        ptep = early_alloc_pgtable(PAGE_SIZE);
 127                        BUG_ON(ptep == NULL);
 128                        pmd_populate_kernel(&init_mm, pmdp, ptep);
 129                }
 130                ptep = pte_offset_kernel(pmdp, ea);
 131                set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 132                                                          __pgprot(flags)));
 133#else /* CONFIG_PPC_MMU_NOHASH */
 134                /*
 135                 * If the mm subsystem is not fully up, we cannot create a
 136                 * linux page table entry for this mapping.  Simply bolt an
 137                 * entry in the hardware page table.
 138                 *
 139                 */
 140                if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
 141                                      mmu_io_psize, mmu_kernel_ssize)) {
 142                        printk(KERN_ERR "Failed to do bolted mapping IO "
 143                               "memory at %016lx !\n", pa);
 144                        return -ENOMEM;
 145                }
 146#endif /* !CONFIG_PPC_MMU_NOHASH */
 147        }
 148        return 0;
 149}
 150
 151
 152/**
 153 * __ioremap_at - Low level function to establish the page tables
 154 *                for an IO mapping
 155 */
 156void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
 157                            unsigned long flags)
 158{
 159        unsigned long i;
 160
 161        /* Make sure we have the base flags */
 162        if ((flags & _PAGE_PRESENT) == 0)
 163                flags |= pgprot_val(PAGE_KERNEL);
 164
 165        /* Non-cacheable page cannot be coherent */
 166        if (flags & _PAGE_NO_CACHE)
 167                flags &= ~_PAGE_COHERENT;
 168
 169        /* We don't support the 4K PFN hack with ioremap */
 170        if (flags & _PAGE_4K_PFN)
 171                return NULL;
 172
 173        WARN_ON(pa & ~PAGE_MASK);
 174        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 175        WARN_ON(size & ~PAGE_MASK);
 176
 177        for (i = 0; i < size; i += PAGE_SIZE)
 178                if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
 179                        return NULL;
 180
 181        return (void __iomem *)ea;
 182}
 183
 184/**
 185 * __iounmap_from - Low level function to tear down the page tables
 186 *                  for an IO mapping. This is used for mappings that
 187 *                  are manipulated manually, like partial unmapping of
 188 *                  PCI IOs or ISA space.
 189 */
 190void __iounmap_at(void *ea, unsigned long size)
 191{
 192        WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 193        WARN_ON(size & ~PAGE_MASK);
 194
 195        unmap_kernel_range((unsigned long)ea, size);
 196}
 197
 198void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
 199                                unsigned long flags, void *caller)
 200{
 201        phys_addr_t paligned;
 202        void __iomem *ret;
 203
 204        /*
 205         * Choose an address to map it to.
 206         * Once the imalloc system is running, we use it.
 207         * Before that, we map using addresses going
 208         * up from ioremap_bot.  imalloc will use
 209         * the addresses from ioremap_bot through
 210         * IMALLOC_END
 211         * 
 212         */
 213        paligned = addr & PAGE_MASK;
 214        size = PAGE_ALIGN(addr + size) - paligned;
 215
 216        if ((size == 0) || (paligned == 0))
 217                return NULL;
 218
 219        if (mem_init_done) {
 220                struct vm_struct *area;
 221
 222                area = __get_vm_area_caller(size, VM_IOREMAP,
 223                                            ioremap_bot, IOREMAP_END,
 224                                            caller);
 225                if (area == NULL)
 226                        return NULL;
 227
 228                area->phys_addr = paligned;
 229                ret = __ioremap_at(paligned, area->addr, size, flags);
 230                if (!ret)
 231                        vunmap(area->addr);
 232        } else {
 233                ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
 234                if (ret)
 235                        ioremap_bot += size;
 236        }
 237
 238        if (ret)
 239                ret += addr & ~PAGE_MASK;
 240        return ret;
 241}
 242
 243void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
 244                         unsigned long flags)
 245{
 246        return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 247}
 248
 249void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 250{
 251        unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
 252        void *caller = __builtin_return_address(0);
 253
 254        if (ppc_md.ioremap)
 255                return ppc_md.ioremap(addr, size, flags, caller);
 256        return __ioremap_caller(addr, size, flags, caller);
 257}
 258
 259void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
 260{
 261        unsigned long flags = _PAGE_NO_CACHE;
 262        void *caller = __builtin_return_address(0);
 263
 264        if (ppc_md.ioremap)
 265                return ppc_md.ioremap(addr, size, flags, caller);
 266        return __ioremap_caller(addr, size, flags, caller);
 267}
 268
 269void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
 270                             unsigned long flags)
 271{
 272        void *caller = __builtin_return_address(0);
 273
 274        /* writeable implies dirty for kernel addresses */
 275        if (flags & _PAGE_RW)
 276                flags |= _PAGE_DIRTY;
 277
 278        /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
 279        flags &= ~(_PAGE_USER | _PAGE_EXEC);
 280
 281#ifdef _PAGE_BAP_SR
 282        /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
 283         * which means that we just cleared supervisor access... oops ;-) This
 284         * restores it
 285         */
 286        flags |= _PAGE_BAP_SR;
 287#endif
 288
 289        if (ppc_md.ioremap)
 290                return ppc_md.ioremap(addr, size, flags, caller);
 291        return __ioremap_caller(addr, size, flags, caller);
 292}
 293
 294
 295/*  
 296 * Unmap an IO region and remove it from imalloc'd list.
 297 * Access to IO memory should be serialized by driver.
 298 */
 299void __iounmap(volatile void __iomem *token)
 300{
 301        void *addr;
 302
 303        if (!mem_init_done)
 304                return;
 305        
 306        addr = (void *) ((unsigned long __force)
 307                         PCI_FIX_ADDR(token) & PAGE_MASK);
 308        if ((unsigned long)addr < ioremap_bot) {
 309                printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
 310                       " at 0x%p\n", addr);
 311                return;
 312        }
 313        vunmap(addr);
 314}
 315
 316void iounmap(volatile void __iomem *token)
 317{
 318        if (ppc_md.iounmap)
 319                ppc_md.iounmap(token);
 320        else
 321                __iounmap(token);
 322}
 323
 324EXPORT_SYMBOL(ioremap);
 325EXPORT_SYMBOL(ioremap_wc);
 326EXPORT_SYMBOL(ioremap_prot);
 327EXPORT_SYMBOL(__ioremap);
 328EXPORT_SYMBOL(__ioremap_at);
 329EXPORT_SYMBOL(iounmap);
 330EXPORT_SYMBOL(__iounmap);
 331EXPORT_SYMBOL(__iounmap_at);
 332