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  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
  11  *
  12  *  Derived from "arch/i386/mm/init.c"
  13  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  14  *
  15  *  Dave Engebretsen <engebret@us.ibm.com>
  16  *      Rework for PPC64 port.
  17  *
  18  *  This program is free software; you can redistribute it and/or
  19  *  modify it under the terms of the GNU General Public License
  20  *  as published by the Free Software Foundation; either version
  21  *  2 of the License, or (at your option) any later version.
  22  *
  23  */
  24
  25 #include <linux/signal.h>
  26 #include <linux/sched.h>
  27 #include <linux/kernel.h>
  28 #include <linux/errno.h>
  29 #include <linux/string.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/delay.h>
  38 #include <linux/bootmem.h>
  39 #include <linux/highmem.h>
  40 #include <linux/idr.h>
  41 #include <linux/nodemask.h>
  42 #include <linux/module.h>
  43
  44 #include <asm/pgalloc.h>
  45 #include <asm/page.h>
  46 #include <asm/prom.h>
  47 #include <asm/lmb.h>
  48 #include <asm/rtas.h>
  49 #include <asm/io.h>
  50 #include <asm/mmu_context.h>
  51 #include <asm/pgtable.h>
  52 #include <asm/mmu.h>
  53 #include <asm/uaccess.h>
  54 #include <asm/smp.h>
  55 #include <asm/machdep.h>
  56 #include <asm/tlb.h>
  57 #include <asm/eeh.h>
  58 #include <asm/processor.h>
  59 #include <asm/mmzone.h>
  60 #include <asm/cputable.h>
  61 #include <asm/sections.h>
  62 #include <asm/system.h>
  63 #include <asm/iommu.h>
  64 #include <asm/abs_addr.h>
  65 #include <asm/vdso.h>
  66
  67 #include "mmu_decl.h"
  68
  69 unsigned long ioremap_bot = IMALLOC_BASE;
  70 static unsigned long phbs_io_bot = PHBS_IO_BASE;
  71
  72 #ifdef CONFIG_PPC_ISERIES
  73
  74 void __iomem *ioremap(unsigned long addr, unsigned long size)
  75 {
  76         return (void __iomem *)addr;
  77 }
  78
  79 extern void __iomem *__ioremap(unsigned long addr, unsigned long size,
  80                        unsigned long flags)
  81 {
  82         return (void __iomem *)addr;
  83 }
  84
  85 void iounmap(volatile void __iomem *addr)
  86 {
  87         return;
  88 }
  89
  90 #else
  91
  92 /*
  93  * map_io_page currently only called by __ioremap
  94  * map_io_page adds an entry to the ioremap page table
  95  * and adds an entry to the HPT, possibly bolting it
  96  */
  97 static int map_io_page(unsigned long ea, unsigned long pa, int flags)
  98 {
  99         pgd_t *pgdp;
 100         pud_t *pudp;
 101         pmd_t *pmdp;
 102         pte_t *ptep;
 103
 104         if (mem_init_done) {
 105                 pgdp = pgd_offset_k(ea);
 106                 pudp = pud_alloc(&init_mm, pgdp, ea);
 107                 if (!pudp)
 108                         return -ENOMEM;
 109                 pmdp = pmd_alloc(&init_mm, pudp, ea);
 110                 if (!pmdp)
 111                         return -ENOMEM;
 112                 ptep = pte_alloc_kernel(pmdp, ea);
 113                 if (!ptep)
 114                         return -ENOMEM;
 115                 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 116                                                           __pgprot(flags)));
 117         } else {
 118                 /*
 119                  * If the mm subsystem is not fully up, we cannot create a
 120                  * linux page table entry for this mapping.  Simply bolt an
 121                  * entry in the hardware page table.
 122                  *
 123                  */
 124                 if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
 125                                       mmu_virtual_psize)) {
 126                         printk(KERN_ERR "Failed to do bolted mapping IO "
 127                                "memory at %016lx !\n", pa);
 128                         return -ENOMEM;
 129                 }
 130         }
 131         return 0;
 132 }
 133
 134
 135 static void __iomem * __ioremap_com(unsigned long addr, unsigned long pa,
 136                             unsigned long ea, unsigned long size,
 137                             unsigned long flags)
 138 {
 139         unsigned long i;
 140
 141         if ((flags & _PAGE_PRESENT) == 0)
 142                 flags |= pgprot_val(PAGE_KERNEL);
 143
 144         for (i = 0; i < size; i += PAGE_SIZE)
 145                 if (map_io_page(ea+i, pa+i, flags))
 146                         return NULL;
 147
 148         return (void __iomem *) (ea + (addr & ~PAGE_MASK));
 149 }
 150
 151
 152 void __iomem *
 153 ioremap(unsigned long addr, unsigned long size)
 154 {
 155         return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
 156 }
 157
 158 void __iomem * __ioremap(unsigned long addr, unsigned long size,
 159                          unsigned long flags)
 160 {
 161         unsigned long pa, ea;
 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         pa = addr & PAGE_MASK;
 174         size = PAGE_ALIGN(addr + size) - pa;
 175
 176         if ((size == 0) || (pa == 0))
 177                 return NULL;
 178
 179         if (mem_init_done) {
 180                 struct vm_struct *area;
 181                 area = im_get_free_area(size);
 182                 if (area == NULL)
 183                         return NULL;
 184                 ea = (unsigned long)(area->addr);
 185                 ret = __ioremap_com(addr, pa, ea, size, flags);
 186                 if (!ret)
 187                         im_free(area->addr);
 188         } else {
 189                 ea = ioremap_bot;
 190                 ret = __ioremap_com(addr, pa, ea, size, flags);
 191                 if (ret)
 192                         ioremap_bot += size;
 193         }
 194         return ret;
 195 }
 196
 197 #define IS_PAGE_ALIGNED(_val) ((_val) == ((_val) & PAGE_MASK))
 198
 199 int __ioremap_explicit(unsigned long pa, unsigned long ea,
 200                        unsigned long size, unsigned long flags)
 201 {
 202         struct vm_struct *area;
 203         void __iomem *ret;
 204
 205         /* For now, require page-aligned values for pa, ea, and size */
 206         if (!IS_PAGE_ALIGNED(pa) || !IS_PAGE_ALIGNED(ea) ||
 207             !IS_PAGE_ALIGNED(size)) {
 208                 printk(KERN_ERR "unaligned value in %s\n", __FUNCTION__);
 209                 return 1;
 210         }
 211
 212         if (!mem_init_done) {
 213                 /* Two things to consider in this case:
 214                  * 1) No records will be kept (imalloc, etc) that the region
 215                  *    has been remapped
 216                  * 2) It won't be easy to iounmap() the region later (because
 217                  *    of 1)
 218                  */
 219                 ;
 220         } else {
 221                 area = im_get_area(ea, size,
 222                         IM_REGION_UNUSED|IM_REGION_SUBSET|IM_REGION_EXISTS);
 223                 if (area == NULL) {
 224                         /* Expected when PHB-dlpar is in play */
 225                         return 1;
 226                 }
 227                 if (ea != (unsigned long) area->addr) {
 228                         printk(KERN_ERR "unexpected addr return from "
 229                                "im_get_area\n");
 230                         return 1;
 231                 }
 232         }
 233
 234         ret = __ioremap_com(pa, pa, ea, size, flags);
 235         if (ret == NULL) {
 236                 printk(KERN_ERR "ioremap_explicit() allocation failure !\n");
 237                 return 1;
 238         }
 239         if (ret != (void *) ea) {
 240                 printk(KERN_ERR "__ioremap_com() returned unexpected addr\n");
 241                 return 1;
 242         }
 243
 244         return 0;
 245 }
 246
 247 /*
 248  * Unmap an IO region and remove it from imalloc'd list.
 249  * Access to IO memory should be serialized by driver.
 250  * This code is modeled after vmalloc code - unmap_vm_area()
 251  *
 252  * XXX  what about calls before mem_init_done (ie python_countermeasures())
 253  */
 254 void iounmap(volatile void __iomem *token)
 255 {
 256         void *addr;
 257
 258         if (!mem_init_done)
 259                 return;
 260
 261         addr = (void *) ((unsigned long __force) token & PAGE_MASK);
 262
 263         im_free(addr);
 264 }
 265
 266 static int iounmap_subset_regions(unsigned long addr, unsigned long size)
 267 {
 268         struct vm_struct *area;
 269
 270         /* Check whether subsets of this region exist */
 271         area = im_get_area(addr, size, IM_REGION_SUPERSET);
 272         if (area == NULL)
 273                 return 1;
 274
 275         while (area) {
 276                 iounmap((void __iomem *) area->addr);
 277                 area = im_get_area(addr, size,
 278                                 IM_REGION_SUPERSET);
 279         }
 280
 281         return 0;
 282 }
 283
 284 int iounmap_explicit(volatile void __iomem *start, unsigned long size)
 285 {
 286         struct vm_struct *area;
 287         unsigned long addr;
 288         int rc;
 289
 290         addr = (unsigned long __force) start & PAGE_MASK;
 291
 292         /* Verify that the region either exists or is a subset of an existing
 293          * region.  In the latter case, split the parent region to create
 294          * the exact region
 295          */
 296         area = im_get_area(addr, size,
 297                             IM_REGION_EXISTS | IM_REGION_SUBSET);
 298         if (area == NULL) {
 299                 /* Determine whether subset regions exist.  If so, unmap */
 300                 rc = iounmap_subset_regions(addr, size);
 301                 if (rc) {
 302                         printk(KERN_ERR
 303                                "%s() cannot unmap nonexistent range 0x%lx\n",
 304                                 __FUNCTION__, addr);
 305                         return 1;
 306                 }
 307         } else {
 308                 iounmap((void __iomem *) area->addr);
 309         }
 310         /*
 311          * FIXME! This can't be right:
 312         iounmap(area->addr);
 313          * Maybe it should be "iounmap(area);"
 314          */
 315         return 0;
 316 }
 317
 318 #endif
 319
 320 EXPORT_SYMBOL(ioremap);
 321 EXPORT_SYMBOL(__ioremap);
 322 EXPORT_SYMBOL(iounmap);
 323
 324 void __iomem * reserve_phb_iospace(unsigned long size)
 325 {
 326         void __iomem *virt_addr;
 327
 328         if (phbs_io_bot >= IMALLOC_BASE)
 329                 panic("reserve_phb_iospace(): phb io space overflow\n");
 330
 331         virt_addr = (void __iomem *) phbs_io_bot;
 332         phbs_io_bot += size;
 333
 334         return virt_addr;
 335 }