arch/powerpc/mm/pgtable64.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/config.h>
  26 #include <linux/signal.h>
  27 #include <linux/sched.h>
  28 #include <linux/kernel.h>
  29 #include <linux/errno.h>
  30 #include <linux/string.h>
  31 #include <linux/types.h>
  32 #include <linux/mman.h>
  33 #include <linux/mm.h>
  34 #include <linux/swap.h>
  35 #include <linux/stddef.h>
  36 #include <linux/vmalloc.h>
  37 #include <linux/init.h>
  38 #include <linux/delay.h>
  39 #include <linux/bootmem.h>
  40 #include <linux/highmem.h>
  41 #include <linux/idr.h>
  42 #include <linux/nodemask.h>
  43 #include <linux/module.h>
  44
  45 #include <asm/pgalloc.h>
  46 #include <asm/page.h>
  47 #include <asm/prom.h>
  48 #include <asm/lmb.h>
  49 #include <asm/rtas.h>
  50 #include <asm/io.h>
  51 #include <asm/mmu_context.h>
  52 #include <asm/pgtable.h>
  53 #include <asm/mmu.h>
  54 #include <asm/uaccess.h>
  55 #include <asm/smp.h>
  56 #include <asm/machdep.h>
  57 #include <asm/tlb.h>
  58 #include <asm/eeh.h>
  59 #include <asm/processor.h>
  60 #include <asm/mmzone.h>
  61 #include <asm/cputable.h>
  62 #include <asm/ppcdebug.h>
  63 #include <asm/sections.h>
  64 #include <asm/system.h>
  65 #include <asm/iommu.h>
  66 #include <asm/abs_addr.h>
  67 #include <asm/vdso.h>
  68 #include <asm/imalloc.h>
  69
  70 #if PGTABLE_RANGE > USER_VSID_RANGE
  71 #warning Limited user VSID range means pagetable space is wasted
  72 #endif
  73
  74 #if (TASK_SIZE_USER64 < PGTABLE_RANGE) && (TASK_SIZE_USER64 < USER_VSID_RANGE)
  75 #warning TASK_SIZE is smaller than it needs to be.
  76 #endif
  77
  78 int mem_init_done;
  79 unsigned long ioremap_bot = IMALLOC_BASE;
  80 static unsigned long phbs_io_bot = PHBS_IO_BASE;
  81
  82 extern pgd_t swapper_pg_dir[];
  83 extern struct task_struct *current_set[NR_CPUS];
  84
  85 unsigned long klimit = (unsigned long)_end;
  86
  87 /* max amount of RAM to use */
  88 unsigned long __max_memory;
  89
  90 /* info on what we think the IO hole is */
  91 unsigned long   io_hole_start;
  92 unsigned long   io_hole_size;
  93
  94 #ifdef CONFIG_PPC_ISERIES
  95
  96 void __iomem *ioremap(unsigned long addr, unsigned long size)
  97 {
  98         return (void __iomem *)addr;
  99 }
 100
 101 extern void __iomem *__ioremap(unsigned long addr, unsigned long size,
 102                        unsigned long flags)
 103 {
 104         return (void __iomem *)addr;
 105 }
 106
 107 void iounmap(volatile void __iomem *addr)
 108 {
 109         return;
 110 }
 111
 112 #else
 113
 114 /*
 115  * map_io_page currently only called by __ioremap
 116  * map_io_page adds an entry to the ioremap page table
 117  * and adds an entry to the HPT, possibly bolting it
 118  */
 119 static int map_io_page(unsigned long ea, unsigned long pa, int flags)
 120 {
 121         pgd_t *pgdp;
 122         pud_t *pudp;
 123         pmd_t *pmdp;
 124         pte_t *ptep;
 125         unsigned long vsid;
 126
 127         if (mem_init_done) {
 128                 spin_lock(&init_mm.page_table_lock);
 129                 pgdp = pgd_offset_k(ea);
 130                 pudp = pud_alloc(&init_mm, pgdp, ea);
 131                 if (!pudp)
 132                         return -ENOMEM;
 133                 pmdp = pmd_alloc(&init_mm, pudp, ea);
 134                 if (!pmdp)
 135                         return -ENOMEM;
 136                 ptep = pte_alloc_kernel(&init_mm, pmdp, ea);
 137                 if (!ptep)
 138                         return -ENOMEM;
 139                 set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 140                                                           __pgprot(flags)));
 141                 spin_unlock(&init_mm.page_table_lock);
 142         } else {
 143                 unsigned long va, vpn, hash, hpteg;
 144
 145                 /*
 146                  * If the mm subsystem is not fully up, we cannot create a
 147                  * linux page table entry for this mapping.  Simply bolt an
 148                  * entry in the hardware page table.
 149                  */
 150                 vsid = get_kernel_vsid(ea);
 151                 va = (vsid << 28) | (ea & 0xFFFFFFF);
 152                 vpn = va >> PAGE_SHIFT;
 153
 154                 hash = hpt_hash(vpn, 0);
 155
 156                 hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 157
 158                 /* Panic if a pte grpup is full */
 159                 if (ppc_md.hpte_insert(hpteg, va, pa >> PAGE_SHIFT,
 160                                        HPTE_V_BOLTED,
 161                                        _PAGE_NO_CACHE|_PAGE_GUARDED|PP_RWXX)
 162                     == -1) {
 163                         panic("map_io_page: could not insert mapping");
 164                 }
 165         }
 166         return 0;
 167 }
 168
 169
 170 static void __iomem * __ioremap_com(unsigned long addr, unsigned long pa,
 171                             unsigned long ea, unsigned long size,
 172                             unsigned long flags)
 173 {
 174         unsigned long i;
 175
 176         if ((flags & _PAGE_PRESENT) == 0)
 177                 flags |= pgprot_val(PAGE_KERNEL);
 178
 179         for (i = 0; i < size; i += PAGE_SIZE)
 180                 if (map_io_page(ea+i, pa+i, flags))
 181                         return NULL;
 182
 183         return (void __iomem *) (ea + (addr & ~PAGE_MASK));
 184 }
 185
 186
 187 void __iomem *
 188 ioremap(unsigned long addr, unsigned long size)
 189 {
 190         return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
 191 }
 192
 193 void __iomem * __ioremap(unsigned long addr, unsigned long size,
 194                          unsigned long flags)
 195 {
 196         unsigned long pa, ea;
 197         void __iomem *ret;
 198
 199         /*
 200          * Choose an address to map it to.
 201          * Once the imalloc system is running, we use it.
 202          * Before that, we map using addresses going
 203          * up from ioremap_bot.  imalloc will use
 204          * the addresses from ioremap_bot through
 205          * IMALLOC_END
 206          *
 207          */
 208         pa = addr & PAGE_MASK;
 209         size = PAGE_ALIGN(addr + size) - pa;
 210
 211         if (size == 0)
 212                 return NULL;
 213
 214         if (mem_init_done) {
 215                 struct vm_struct *area;
 216                 area = im_get_free_area(size);
 217                 if (area == NULL)
 218                         return NULL;
 219                 ea = (unsigned long)(area->addr);
 220                 ret = __ioremap_com(addr, pa, ea, size, flags);
 221                 if (!ret)
 222                         im_free(area->addr);
 223         } else {
 224                 ea = ioremap_bot;
 225                 ret = __ioremap_com(addr, pa, ea, size, flags);
 226                 if (ret)
 227                         ioremap_bot += size;
 228         }
 229         return ret;
 230 }
 231
 232 #define IS_PAGE_ALIGNED(_val) ((_val) == ((_val) & PAGE_MASK))
 233
 234 int __ioremap_explicit(unsigned long pa, unsigned long ea,
 235                        unsigned long size, unsigned long flags)
 236 {
 237         struct vm_struct *area;
 238         void __iomem *ret;
 239
 240         /* For now, require page-aligned values for pa, ea, and size */
 241         if (!IS_PAGE_ALIGNED(pa) || !IS_PAGE_ALIGNED(ea) ||
 242             !IS_PAGE_ALIGNED(size)) {
 243                 printk(KERN_ERR "unaligned value in %s\n", __FUNCTION__);
 244                 return 1;
 245         }
 246
 247         if (!mem_init_done) {
 248                 /* Two things to consider in this case:
 249                  * 1) No records will be kept (imalloc, etc) that the region
 250                  *    has been remapped
 251                  * 2) It won't be easy to iounmap() the region later (because
 252                  *    of 1)
 253                  */
 254                 ;
 255         } else {
 256                 area = im_get_area(ea, size,
 257                         IM_REGION_UNUSED|IM_REGION_SUBSET|IM_REGION_EXISTS);
 258                 if (area == NULL) {
 259                         /* Expected when PHB-dlpar is in play */
 260                         return 1;
 261                 }
 262                 if (ea != (unsigned long) area->addr) {
 263                         printk(KERN_ERR "unexpected addr return from "
 264                                "im_get_area\n");
 265                         return 1;
 266                 }
 267         }
 268
 269         ret = __ioremap_com(pa, pa, ea, size, flags);
 270         if (ret == NULL) {
 271                 printk(KERN_ERR "ioremap_explicit() allocation failure !\n");
 272                 return 1;
 273         }
 274         if (ret != (void *) ea) {
 275                 printk(KERN_ERR "__ioremap_com() returned unexpected addr\n");
 276                 return 1;
 277         }
 278
 279         return 0;
 280 }
 281
 282 /*
 283  * Unmap an IO region and remove it from imalloc'd list.
 284  * Access to IO memory should be serialized by driver.
 285  * This code is modeled after vmalloc code - unmap_vm_area()
 286  *
 287  * XXX  what about calls before mem_init_done (ie python_countermeasures())
 288  */
 289 void iounmap(volatile void __iomem *token)
 290 {
 291         void *addr;
 292
 293         if (!mem_init_done)
 294                 return;
 295
 296         addr = (void *) ((unsigned long __force) token & PAGE_MASK);
 297
 298         im_free(addr);
 299 }
 300
 301 static int iounmap_subset_regions(unsigned long addr, unsigned long size)
 302 {
 303         struct vm_struct *area;
 304
 305         /* Check whether subsets of this region exist */
 306         area = im_get_area(addr, size, IM_REGION_SUPERSET);
 307         if (area == NULL)
 308                 return 1;
 309
 310         while (area) {
 311                 iounmap((void __iomem *) area->addr);
 312                 area = im_get_area(addr, size,
 313                                 IM_REGION_SUPERSET);
 314         }
 315
 316         return 0;
 317 }
 318
 319 int iounmap_explicit(volatile void __iomem *start, unsigned long size)
 320 {
 321         struct vm_struct *area;
 322         unsigned long addr;
 323         int rc;
 324
 325         addr = (unsigned long __force) start & PAGE_MASK;
 326
 327         /* Verify that the region either exists or is a subset of an existing
 328          * region.  In the latter case, split the parent region to create
 329          * the exact region
 330          */
 331         area = im_get_area(addr, size,
 332                             IM_REGION_EXISTS | IM_REGION_SUBSET);
 333         if (area == NULL) {
 334                 /* Determine whether subset regions exist.  If so, unmap */
 335                 rc = iounmap_subset_regions(addr, size);
 336                 if (rc) {
 337                         printk(KERN_ERR
 338                                "%s() cannot unmap nonexistent range 0x%lx\n",
 339                                 __FUNCTION__, addr);
 340                         return 1;
 341                 }
 342         } else {
 343                 iounmap((void __iomem *) area->addr);
 344         }
 345         /*
 346          * FIXME! This can't be right:
 347         iounmap(area->addr);
 348          * Maybe it should be "iounmap(area);"
 349          */
 350         return 0;
 351 }
 352
 353 #endif
 354
 355 EXPORT_SYMBOL(ioremap);
 356 EXPORT_SYMBOL(__ioremap);
 357 EXPORT_SYMBOL(iounmap);