arch/powerpc/mm/pgtable_64.c

   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/firmware.h>
  55
  56 #include "mmu_decl.h"
  57
  58 /* Some sanity checking */
  59 #if TASK_SIZE_USER64 > PGTABLE_RANGE
  60 #error TASK_SIZE_USER64 exceeds pagetable range
  61 #endif
  62
  63 #ifdef CONFIG_PPC_STD_MMU_64
  64 #if TASK_SIZE_USER64 > (1UL << (USER_ESID_BITS + SID_SHIFT))
  65 #error TASK_SIZE_USER64 exceeds user VSID range
  66 #endif
  67 #endif
  68
  69 unsigned long ioremap_bot = IOREMAP_BASE;
  70
  71 #ifdef CONFIG_PPC_MMU_NOHASH
  72 static void *early_alloc_pgtable(unsigned long size)
  73 {
  74         void *pt;
  75
  76         if (init_bootmem_done)
  77                 pt = __alloc_bootmem(size, size, __pa(MAX_DMA_ADDRESS));
  78         else
  79                 pt = __va(memblock_alloc_base(size, size,
  80                                          __pa(MAX_DMA_ADDRESS)));
  81         memset(pt, 0, size);
  82
  83         return pt;
  84 }
  85 #endif /* CONFIG_PPC_MMU_NOHASH */
  86
  87 /*
  88  * map_kernel_page currently only called by __ioremap
  89  * map_kernel_page adds an entry to the ioremap page table
  90  * and adds an entry to the HPT, possibly bolting it
  91  */
  92 int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
  93 {
  94         pgd_t *pgdp;
  95         pud_t *pudp;
  96         pmd_t *pmdp;
  97         pte_t *ptep;
  98
  99         if (slab_is_available()) {
 100                 pgdp = pgd_offset_k(ea);
 101                 pudp = pud_alloc(&init_mm, pgdp, ea);
 102                 if (!pudp)
 103                         return -ENOMEM;
 104                 pmdp = pmd_alloc(&init_mm, pudp, ea);
 105                 if (!pmdp)
 106                         return -ENOMEM;
 107                 ptep = pte_alloc_kernel(pmdp, ea);
 108                 if (!ptep)
 109                         return -ENOMEM;
 110                 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 111                                                           __pgprot(flags)));
 112         } else {
 113 #ifdef CONFIG_PPC_MMU_NOHASH
 114                 /* Warning ! This will blow up if bootmem is not initialized
 115                  * which our ppc64 code is keen to do that, we'll need to
 116                  * fix it and/or be more careful
 117                  */
 118                 pgdp = pgd_offset_k(ea);
 119 #ifdef PUD_TABLE_SIZE
 120                 if (pgd_none(*pgdp)) {
 121                         pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
 122                         BUG_ON(pudp == NULL);
 123                         pgd_populate(&init_mm, pgdp, pudp);
 124                 }
 125 #endif /* PUD_TABLE_SIZE */
 126                 pudp = pud_offset(pgdp, ea);
 127                 if (pud_none(*pudp)) {
 128                         pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
 129                         BUG_ON(pmdp == NULL);
 130                         pud_populate(&init_mm, pudp, pmdp);
 131                 }
 132                 pmdp = pmd_offset(pudp, ea);
 133                 if (!pmd_present(*pmdp)) {
 134                         ptep = early_alloc_pgtable(PAGE_SIZE);
 135                         BUG_ON(ptep == NULL);
 136                         pmd_populate_kernel(&init_mm, pmdp, ptep);
 137                 }
 138                 ptep = pte_offset_kernel(pmdp, ea);
 139                 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 140                                                           __pgprot(flags)));
 141 #else /* CONFIG_PPC_MMU_NOHASH */
 142                 /*
 143                  * If the mm subsystem is not fully up, we cannot create a
 144                  * linux page table entry for this mapping.  Simply bolt an
 145                  * entry in the hardware page table.
 146                  *
 147                  */
 148                 if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
 149                                       mmu_io_psize, mmu_kernel_ssize)) {
 150                         printk(KERN_ERR "Failed to do bolted mapping IO "
 151                                "memory at %016lx !\n", pa);
 152                         return -ENOMEM;
 153                 }
 154 #endif /* !CONFIG_PPC_MMU_NOHASH */
 155         }
 156         return 0;
 157 }
 158
 159
 160 /**
 161  * __ioremap_at - Low level function to establish the page tables
 162  *                for an IO mapping
 163  */
 164 void __iomem * __ioremap_at(phys_addr_t pa, void *ea, unsigned long size,
 165                             unsigned long flags)
 166 {
 167         unsigned long i;
 168
 169         /* Make sure we have the base flags */
 170         if ((flags & _PAGE_PRESENT) == 0)
 171                 flags |= pgprot_val(PAGE_KERNEL);
 172
 173         /* Non-cacheable page cannot be coherent */
 174         if (flags & _PAGE_NO_CACHE)
 175                 flags &= ~_PAGE_COHERENT;
 176
 177         /* We don't support the 4K PFN hack with ioremap */
 178         if (flags & _PAGE_4K_PFN)
 179                 return NULL;
 180
 181         WARN_ON(pa & ~PAGE_MASK);
 182         WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 183         WARN_ON(size & ~PAGE_MASK);
 184
 185         for (i = 0; i < size; i += PAGE_SIZE)
 186                 if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
 187                         return NULL;
 188
 189         return (void __iomem *)ea;
 190 }
 191
 192 /**
 193  * __iounmap_from - Low level function to tear down the page tables
 194  *                  for an IO mapping. This is used for mappings that
 195  *                  are manipulated manually, like partial unmapping of
 196  *                  PCI IOs or ISA space.
 197  */
 198 void __iounmap_at(void *ea, unsigned long size)
 199 {
 200         WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
 201         WARN_ON(size & ~PAGE_MASK);
 202
 203         unmap_kernel_range((unsigned long)ea, size);
 204 }
 205
 206 void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
 207                                 unsigned long flags, void *caller)
 208 {
 209         phys_addr_t paligned;
 210         void __iomem *ret;
 211
 212         /*
 213          * Choose an address to map it to.
 214          * Once the imalloc system is running, we use it.
 215          * Before that, we map using addresses going
 216          * up from ioremap_bot.  imalloc will use
 217          * the addresses from ioremap_bot through
 218          * IMALLOC_END
 219          *
 220          */
 221         paligned = addr & PAGE_MASK;
 222         size = PAGE_ALIGN(addr + size) - paligned;
 223
 224         if ((size == 0) || (paligned == 0))
 225                 return NULL;
 226
 227         if (mem_init_done) {
 228                 struct vm_struct *area;
 229
 230                 area = __get_vm_area_caller(size, VM_IOREMAP,
 231                                             ioremap_bot, IOREMAP_END,
 232                                             caller);
 233                 if (area == NULL)
 234                         return NULL;
 235
 236                 area->phys_addr = paligned;
 237                 ret = __ioremap_at(paligned, area->addr, size, flags);
 238                 if (!ret)
 239                         vunmap(area->addr);
 240         } else {
 241                 ret = __ioremap_at(paligned, (void *)ioremap_bot, size, flags);
 242                 if (ret)
 243                         ioremap_bot += size;
 244         }
 245
 246         if (ret)
 247                 ret += addr & ~PAGE_MASK;
 248         return ret;
 249 }
 250
 251 void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
 252                          unsigned long flags)
 253 {
 254         return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
 255 }
 256
 257 void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 258 {
 259         unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
 260         void *caller = __builtin_return_address(0);
 261
 262         if (ppc_md.ioremap)
 263                 return ppc_md.ioremap(addr, size, flags, caller);
 264         return __ioremap_caller(addr, size, flags, caller);
 265 }
 266
 267 void __iomem * ioremap_wc(phys_addr_t addr, unsigned long size)
 268 {
 269         unsigned long flags = _PAGE_NO_CACHE;
 270         void *caller = __builtin_return_address(0);
 271
 272         if (ppc_md.ioremap)
 273                 return ppc_md.ioremap(addr, size, flags, caller);
 274         return __ioremap_caller(addr, size, flags, caller);
 275 }
 276
 277 void __iomem * ioremap_prot(phys_addr_t addr, unsigned long size,
 278                              unsigned long flags)
 279 {
 280         void *caller = __builtin_return_address(0);
 281
 282         /* writeable implies dirty for kernel addresses */
 283         if (flags & _PAGE_RW)
 284                 flags |= _PAGE_DIRTY;
 285
 286         /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
 287         flags &= ~(_PAGE_USER | _PAGE_EXEC);
 288
 289 #ifdef _PAGE_BAP_SR
 290         /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
 291          * which means that we just cleared supervisor access... oops ;-) This
 292          * restores it
 293          */
 294         flags |= _PAGE_BAP_SR;
 295 #endif
 296
 297         if (ppc_md.ioremap)
 298                 return ppc_md.ioremap(addr, size, flags, caller);
 299         return __ioremap_caller(addr, size, flags, caller);
 300 }
 301
 302
 303 /*
 304  * Unmap an IO region and remove it from imalloc'd list.
 305  * Access to IO memory should be serialized by driver.
 306  */
 307 void __iounmap(volatile void __iomem *token)
 308 {
 309         void *addr;
 310
 311         if (!mem_init_done)
 312                 return;
 313
 314         addr = (void *) ((unsigned long __force)
 315                          PCI_FIX_ADDR(token) & PAGE_MASK);
 316         if ((unsigned long)addr < ioremap_bot) {
 317                 printk(KERN_WARNING "Attempt to iounmap early bolted mapping"
 318                        " at 0x%p\n", addr);
 319                 return;
 320         }
 321         vunmap(addr);
 322 }
 323
 324 void iounmap(volatile void __iomem *token)
 325 {
 326         if (ppc_md.iounmap)
 327                 ppc_md.iounmap(token);
 328         else
 329                 __iounmap(token);
 330 }
 331
 332 EXPORT_SYMBOL(ioremap);
 333 EXPORT_SYMBOL(ioremap_wc);
 334 EXPORT_SYMBOL(ioremap_prot);
 335 EXPORT_SYMBOL(__ioremap);
 336 EXPORT_SYMBOL(__ioremap_at);
 337 EXPORT_SYMBOL(iounmap);
 338 EXPORT_SYMBOL(__iounmap);
 339 EXPORT_SYMBOL(__iounmap_at);