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 #include <asm/firmware.h>
  67
  68 #include "mmu_decl.h"
  69
  70 unsigned long ioremap_bot = IMALLOC_BASE;
  71 static unsigned long phbs_io_bot = PHBS_IO_BASE;
  72
  73 /*
  74  * map_io_page currently only called by __ioremap
  75  * map_io_page adds an entry to the ioremap page table
  76  * and adds an entry to the HPT, possibly bolting it
  77  */
  78 static int map_io_page(unsigned long ea, unsigned long pa, int flags)
  79 {
  80         pgd_t *pgdp;
  81         pud_t *pudp;
  82         pmd_t *pmdp;
  83         pte_t *ptep;
  84
  85         if (mem_init_done) {
  86                 pgdp = pgd_offset_k(ea);
  87                 pudp = pud_alloc(&init_mm, pgdp, ea);
  88                 if (!pudp)
  89                         return -ENOMEM;
  90                 pmdp = pmd_alloc(&init_mm, pudp, ea);
  91                 if (!pmdp)
  92                         return -ENOMEM;
  93                 ptep = pte_alloc_kernel(pmdp, ea);
  94                 if (!ptep)
  95                         return -ENOMEM;
  96                 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
  97                                                           __pgprot(flags)));
  98         } else {
  99                 /*
 100                  * If the mm subsystem is not fully up, we cannot create a
 101                  * linux page table entry for this mapping.  Simply bolt an
 102                  * entry in the hardware page table.
 103                  *
 104                  */
 105                 if (htab_bolt_mapping(ea, ea + PAGE_SIZE, pa, flags,
 106                                       mmu_io_psize)) {
 107                         printk(KERN_ERR "Failed to do bolted mapping IO "
 108                                "memory at %016lx !\n", pa);
 109                         return -ENOMEM;
 110                 }
 111         }
 112         return 0;
 113 }
 114
 115
 116 static void __iomem * __ioremap_com(phys_addr_t addr, unsigned long pa,
 117                             unsigned long ea, unsigned long size,
 118                             unsigned long flags)
 119 {
 120         unsigned long i;
 121
 122         if ((flags & _PAGE_PRESENT) == 0)
 123                 flags |= pgprot_val(PAGE_KERNEL);
 124
 125         for (i = 0; i < size; i += PAGE_SIZE)
 126                 if (map_io_page(ea+i, pa+i, flags))
 127                         return NULL;
 128
 129         return (void __iomem *) (ea + (addr & ~PAGE_MASK));
 130 }
 131
 132 void __iomem * __ioremap(phys_addr_t addr, unsigned long size,
 133                          unsigned long flags)
 134 {
 135         unsigned long pa, ea;
 136         void __iomem *ret;
 137
 138         /*
 139          * Choose an address to map it to.
 140          * Once the imalloc system is running, we use it.
 141          * Before that, we map using addresses going
 142          * up from ioremap_bot.  imalloc will use
 143          * the addresses from ioremap_bot through
 144          * IMALLOC_END
 145          *
 146          */
 147         pa = addr & PAGE_MASK;
 148         size = PAGE_ALIGN(addr + size) - pa;
 149
 150         if ((size == 0) || (pa == 0))
 151                 return NULL;
 152
 153         if (mem_init_done) {
 154                 struct vm_struct *area;
 155                 area = im_get_free_area(size);
 156                 if (area == NULL)
 157                         return NULL;
 158                 ea = (unsigned long)(area->addr);
 159                 ret = __ioremap_com(addr, pa, ea, size, flags);
 160                 if (!ret)
 161                         im_free(area->addr);
 162         } else {
 163                 ea = ioremap_bot;
 164                 ret = __ioremap_com(addr, pa, ea, size, flags);
 165                 if (ret)
 166                         ioremap_bot += size;
 167         }
 168         return ret;
 169 }
 170
 171
 172 void __iomem * ioremap(phys_addr_t addr, unsigned long size)
 173 {
 174         unsigned long flags = _PAGE_NO_CACHE | _PAGE_GUARDED;
 175
 176         if (ppc_md.ioremap)
 177                 return ppc_md.ioremap(addr, size, flags);
 178         return __ioremap(addr, size, flags);
 179 }
 180
 181 void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
 182                              unsigned long flags)
 183 {
 184         if (ppc_md.ioremap)
 185                 return ppc_md.ioremap(addr, size, flags);
 186         return __ioremap(addr, size, flags);
 187 }
 188
 189
 190 #define IS_PAGE_ALIGNED(_val) ((_val) == ((_val) & PAGE_MASK))
 191
 192 int __ioremap_explicit(phys_addr_t pa, unsigned long ea,
 193                        unsigned long size, unsigned long flags)
 194 {
 195         struct vm_struct *area;
 196         void __iomem *ret;
 197
 198         /* For now, require page-aligned values for pa, ea, and size */
 199         if (!IS_PAGE_ALIGNED(pa) || !IS_PAGE_ALIGNED(ea) ||
 200             !IS_PAGE_ALIGNED(size)) {
 201                 printk(KERN_ERR "unaligned value in %s\n", __FUNCTION__);
 202                 return 1;
 203         }
 204
 205         if (!mem_init_done) {
 206                 /* Two things to consider in this case:
 207                  * 1) No records will be kept (imalloc, etc) that the region
 208                  *    has been remapped
 209                  * 2) It won't be easy to iounmap() the region later (because
 210                  *    of 1)
 211                  */
 212                 ;
 213         } else {
 214                 area = im_get_area(ea, size,
 215                         IM_REGION_UNUSED|IM_REGION_SUBSET|IM_REGION_EXISTS);
 216                 if (area == NULL) {
 217                         /* Expected when PHB-dlpar is in play */
 218                         return 1;
 219                 }
 220                 if (ea != (unsigned long) area->addr) {
 221                         printk(KERN_ERR "unexpected addr return from "
 222                                "im_get_area\n");
 223                         return 1;
 224                 }
 225         }
 226
 227         ret = __ioremap_com(pa, pa, ea, size, flags);
 228         if (ret == NULL) {
 229                 printk(KERN_ERR "ioremap_explicit() allocation failure !\n");
 230                 return 1;
 231         }
 232         if (ret != (void *) ea) {
 233                 printk(KERN_ERR "__ioremap_com() returned unexpected addr\n");
 234                 return 1;
 235         }
 236
 237         return 0;
 238 }
 239
 240 /*
 241  * Unmap an IO region and remove it from imalloc'd list.
 242  * Access to IO memory should be serialized by driver.
 243  * This code is modeled after vmalloc code - unmap_vm_area()
 244  *
 245  * XXX  what about calls before mem_init_done (ie python_countermeasures())
 246  */
 247 void __iounmap(volatile void __iomem *token)
 248 {
 249         void *addr;
 250
 251         if (!mem_init_done)
 252                 return;
 253
 254         addr = (void *) ((unsigned long __force) token & PAGE_MASK);
 255
 256         im_free(addr);
 257 }
 258
 259 void iounmap(volatile void __iomem *token)
 260 {
 261         if (ppc_md.iounmap)
 262                 ppc_md.iounmap(token);
 263         else
 264                 __iounmap(token);
 265 }
 266
 267 static int iounmap_subset_regions(unsigned long addr, unsigned long size)
 268 {
 269         struct vm_struct *area;
 270
 271         /* Check whether subsets of this region exist */
 272         area = im_get_area(addr, size, IM_REGION_SUPERSET);
 273         if (area == NULL)
 274                 return 1;
 275
 276         while (area) {
 277                 iounmap((void __iomem *) area->addr);
 278                 area = im_get_area(addr, size,
 279                                 IM_REGION_SUPERSET);
 280         }
 281
 282         return 0;
 283 }
 284
 285 int __iounmap_explicit(volatile void __iomem *start, unsigned long size)
 286 {
 287         struct vm_struct *area;
 288         unsigned long addr;
 289         int rc;
 290
 291         addr = (unsigned long __force) start & PAGE_MASK;
 292
 293         /* Verify that the region either exists or is a subset of an existing
 294          * region.  In the latter case, split the parent region to create
 295          * the exact region
 296          */
 297         area = im_get_area(addr, size,
 298                             IM_REGION_EXISTS | IM_REGION_SUBSET);
 299         if (area == NULL) {
 300                 /* Determine whether subset regions exist.  If so, unmap */
 301                 rc = iounmap_subset_regions(addr, size);
 302                 if (rc) {
 303                         printk(KERN_ERR
 304                                "%s() cannot unmap nonexistent range 0x%lx\n",
 305                                 __FUNCTION__, addr);
 306                         return 1;
 307                 }
 308         } else {
 309                 iounmap((void __iomem *) area->addr);
 310         }
 311         /*
 312          * FIXME! This can't be right:
 313         iounmap(area->addr);
 314          * Maybe it should be "iounmap(area);"
 315          */
 316         return 0;
 317 }
 318
 319 EXPORT_SYMBOL(ioremap);
 320 EXPORT_SYMBOL(ioremap_flags);
 321 EXPORT_SYMBOL(__ioremap);
 322 EXPORT_SYMBOL(iounmap);
 323 EXPORT_SYMBOL(__iounmap);
 324
 325 static DEFINE_SPINLOCK(phb_io_lock);
 326
 327 void __iomem * reserve_phb_iospace(unsigned long size)
 328 {
 329         void __iomem *virt_addr;
 330
 331         if (phbs_io_bot >= IMALLOC_BASE)
 332                 panic("reserve_phb_iospace(): phb io space overflow\n");
 333
 334         spin_lock(&phb_io_lock);
 335         virt_addr = (void __iomem *) phbs_io_bot;
 336         phbs_io_bot += size;
 337         spin_unlock(&phb_io_lock);
 338
 339         return virt_addr;
 340 }