arch/powerpc/mm/hash_utils_64.c

   1 /*
   2  * PowerPC64 port by Mike Corrigan and Dave Engebretsen
   3  *   {mikejc|engebret}@us.ibm.com
   4  *
   5  *    Copyright (c) 2000 Mike Corrigan <mikejc@us.ibm.com>
   6  *
   7  * SMP scalability work:
   8  *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
   9  *
  10  *    Module name: htab.c
  11  *
  12  *    Description:
  13  *      PowerPC Hashed Page Table functions
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License
  17  * as published by the Free Software Foundation; either version
  18  * 2 of the License, or (at your option) any later version.
  19  */
  20
  21 #undef DEBUG
  22 #undef DEBUG_LOW
  23
  24 #include <linux/spinlock.h>
  25 #include <linux/errno.h>
  26 #include <linux/sched.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/stat.h>
  29 #include <linux/sysctl.h>
  30 #include <linux/export.h>
  31 #include <linux/ctype.h>
  32 #include <linux/cache.h>
  33 #include <linux/init.h>
  34 #include <linux/signal.h>
  35 #include <linux/memblock.h>
  36
  37 #include <asm/processor.h>
  38 #include <asm/pgtable.h>
  39 #include <asm/mmu.h>
  40 #include <asm/mmu_context.h>
  41 #include <asm/page.h>
  42 #include <asm/types.h>
  43 #include <asm/system.h>
  44 #include <asm/uaccess.h>
  45 #include <asm/machdep.h>
  46 #include <asm/prom.h>
  47 #include <asm/abs_addr.h>
  48 #include <asm/tlbflush.h>
  49 #include <asm/io.h>
  50 #include <asm/eeh.h>
  51 #include <asm/tlb.h>
  52 #include <asm/cacheflush.h>
  53 #include <asm/cputable.h>
  54 #include <asm/sections.h>
  55 #include <asm/spu.h>
  56 #include <asm/udbg.h>
  57 #include <asm/code-patching.h>
  58 #include <asm/fadump.h>
  59 #include <asm/firmware.h>
  60
  61 #ifdef DEBUG
  62 #define DBG(fmt...) udbg_printf(fmt)
  63 #else
  64 #define DBG(fmt...)
  65 #endif
  66
  67 #ifdef DEBUG_LOW
  68 #define DBG_LOW(fmt...) udbg_printf(fmt)
  69 #else
  70 #define DBG_LOW(fmt...)
  71 #endif
  72
  73 #define KB (1024)
  74 #define MB (1024*KB)
  75 #define GB (1024L*MB)
  76
  77 /*
  78  * Note:  pte   --> Linux PTE
  79  *        HPTE  --> PowerPC Hashed Page Table Entry
  80  *
  81  * Execution context:
  82  *   htab_initialize is called with the MMU off (of course), but
  83  *   the kernel has been copied down to zero so it can directly
  84  *   reference global data.  At this point it is very difficult
  85  *   to print debug info.
  86  *
  87  */
  88
  89 #ifdef CONFIG_U3_DART
  90 extern unsigned long dart_tablebase;
  91 #endif /* CONFIG_U3_DART */
  92
  93 static unsigned long _SDR1;
  94 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
  95
  96 struct hash_pte *htab_address;
  97 unsigned long htab_size_bytes;
  98 unsigned long htab_hash_mask;
  99 EXPORT_SYMBOL_GPL(htab_hash_mask);
 100 int mmu_linear_psize = MMU_PAGE_4K;
 101 int mmu_virtual_psize = MMU_PAGE_4K;
 102 int mmu_vmalloc_psize = MMU_PAGE_4K;
 103 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 104 int mmu_vmemmap_psize = MMU_PAGE_4K;
 105 #endif
 106 int mmu_io_psize = MMU_PAGE_4K;
 107 int mmu_kernel_ssize = MMU_SEGSIZE_256M;
 108 int mmu_highuser_ssize = MMU_SEGSIZE_256M;
 109 u16 mmu_slb_size = 64;
 110 EXPORT_SYMBOL_GPL(mmu_slb_size);
 111 #ifdef CONFIG_PPC_64K_PAGES
 112 int mmu_ci_restrictions;
 113 #endif
 114 #ifdef CONFIG_DEBUG_PAGEALLOC
 115 static u8 *linear_map_hash_slots;
 116 static unsigned long linear_map_hash_count;
 117 static DEFINE_SPINLOCK(linear_map_hash_lock);
 118 #endif /* CONFIG_DEBUG_PAGEALLOC */
 119
 120 /* There are definitions of page sizes arrays to be used when none
 121  * is provided by the firmware.
 122  */
 123
 124 /* Pre-POWER4 CPUs (4k pages only)
 125  */
 126 static struct mmu_psize_def mmu_psize_defaults_old[] = {
 127         [MMU_PAGE_4K] = {
 128                 .shift  = 12,
 129                 .sllp   = 0,
 130                 .penc   = 0,
 131                 .avpnm  = 0,
 132                 .tlbiel = 0,
 133         },
 134 };
 135
 136 /* POWER4, GPUL, POWER5
 137  *
 138  * Support for 16Mb large pages
 139  */
 140 static struct mmu_psize_def mmu_psize_defaults_gp[] = {
 141         [MMU_PAGE_4K] = {
 142                 .shift  = 12,
 143                 .sllp   = 0,
 144                 .penc   = 0,
 145                 .avpnm  = 0,
 146                 .tlbiel = 1,
 147         },
 148         [MMU_PAGE_16M] = {
 149                 .shift  = 24,
 150                 .sllp   = SLB_VSID_L,
 151                 .penc   = 0,
 152                 .avpnm  = 0x1UL,
 153                 .tlbiel = 0,
 154         },
 155 };
 156
 157 static unsigned long htab_convert_pte_flags(unsigned long pteflags)
 158 {
 159         unsigned long rflags = pteflags & 0x1fa;
 160
 161         /* _PAGE_EXEC -> NOEXEC */
 162         if ((pteflags & _PAGE_EXEC) == 0)
 163                 rflags |= HPTE_R_N;
 164
 165         /* PP bits. PAGE_USER is already PP bit 0x2, so we only
 166          * need to add in 0x1 if it's a read-only user page
 167          */
 168         if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) &&
 169                                          (pteflags & _PAGE_DIRTY)))
 170                 rflags |= 1;
 171
 172         /* Always add C */
 173         return rflags | HPTE_R_C;
 174 }
 175
 176 int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
 177                       unsigned long pstart, unsigned long prot,
 178                       int psize, int ssize)
 179 {
 180         unsigned long vaddr, paddr;
 181         unsigned int step, shift;
 182         int ret = 0;
 183
 184         shift = mmu_psize_defs[psize].shift;
 185         step = 1 << shift;
 186
 187         prot = htab_convert_pte_flags(prot);
 188
 189         DBG("htab_bolt_mapping(%lx..%lx -> %lx (%lx,%d,%d)\n",
 190             vstart, vend, pstart, prot, psize, ssize);
 191
 192         for (vaddr = vstart, paddr = pstart; vaddr < vend;
 193              vaddr += step, paddr += step) {
 194                 unsigned long hash, hpteg;
 195                 unsigned long vsid = get_kernel_vsid(vaddr, ssize);
 196                 unsigned long va = hpt_va(vaddr, vsid, ssize);
 197                 unsigned long tprot = prot;
 198
 199                 /* Make kernel text executable */
 200                 if (overlaps_kernel_text(vaddr, vaddr + step))
 201                         tprot &= ~HPTE_R_N;
 202
 203                 hash = hpt_hash(va, shift, ssize);
 204                 hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
 205
 206                 BUG_ON(!ppc_md.hpte_insert);
 207                 ret = ppc_md.hpte_insert(hpteg, va, paddr, tprot,
 208                                          HPTE_V_BOLTED, psize, ssize);
 209
 210                 if (ret < 0)
 211                         break;
 212 #ifdef CONFIG_DEBUG_PAGEALLOC
 213                 if ((paddr >> PAGE_SHIFT) < linear_map_hash_count)
 214                         linear_map_hash_slots[paddr >> PAGE_SHIFT] = ret | 0x80;
 215 #endif /* CONFIG_DEBUG_PAGEALLOC */
 216         }
 217         return ret < 0 ? ret : 0;
 218 }
 219
 220 #ifdef CONFIG_MEMORY_HOTPLUG
 221 static int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 222                       int psize, int ssize)
 223 {
 224         unsigned long vaddr;
 225         unsigned int step, shift;
 226
 227         shift = mmu_psize_defs[psize].shift;
 228         step = 1 << shift;
 229
 230         if (!ppc_md.hpte_removebolted) {
 231                 printk(KERN_WARNING "Platform doesn't implement "
 232                                 "hpte_removebolted\n");
 233                 return -EINVAL;
 234         }
 235
 236         for (vaddr = vstart; vaddr < vend; vaddr += step)
 237                 ppc_md.hpte_removebolted(vaddr, psize, ssize);
 238
 239         return 0;
 240 }
 241 #endif /* CONFIG_MEMORY_HOTPLUG */
 242
 243 static int __init htab_dt_scan_seg_sizes(unsigned long node,
 244                                          const char *uname, int depth,
 245                                          void *data)
 246 {
 247         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 248         u32 *prop;
 249         unsigned long size = 0;
 250
 251         /* We are scanning "cpu" nodes only */
 252         if (type == NULL || strcmp(type, "cpu") != 0)
 253                 return 0;
 254
 255         prop = (u32 *)of_get_flat_dt_prop(node, "ibm,processor-segment-sizes",
 256                                           &size);
 257         if (prop == NULL)
 258                 return 0;
 259         for (; size >= 4; size -= 4, ++prop) {
 260                 if (prop[0] == 40) {
 261                         DBG("1T segment support detected\n");
 262                         cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
 263                         return 1;
 264                 }
 265         }
 266         cur_cpu_spec->mmu_features &= ~MMU_FTR_NO_SLBIE_B;
 267         return 0;
 268 }
 269
 270 static void __init htab_init_seg_sizes(void)
 271 {
 272         of_scan_flat_dt(htab_dt_scan_seg_sizes, NULL);
 273 }
 274
 275 static int __init htab_dt_scan_page_sizes(unsigned long node,
 276                                           const char *uname, int depth,
 277                                           void *data)
 278 {
 279         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 280         u32 *prop;
 281         unsigned long size = 0;
 282
 283         /* We are scanning "cpu" nodes only */
 284         if (type == NULL || strcmp(type, "cpu") != 0)
 285                 return 0;
 286
 287         prop = (u32 *)of_get_flat_dt_prop(node,
 288                                           "ibm,segment-page-sizes", &size);
 289         if (prop != NULL) {
 290                 DBG("Page sizes from device-tree:\n");
 291                 size /= 4;
 292                 cur_cpu_spec->mmu_features &= ~(MMU_FTR_16M_PAGE);
 293                 while(size > 0) {
 294                         unsigned int shift = prop[0];
 295                         unsigned int slbenc = prop[1];
 296                         unsigned int lpnum = prop[2];
 297                         unsigned int lpenc = 0;
 298                         struct mmu_psize_def *def;
 299                         int idx = -1;
 300
 301                         size -= 3; prop += 3;
 302                         while(size > 0 && lpnum) {
 303                                 if (prop[0] == shift)
 304                                         lpenc = prop[1];
 305                                 prop += 2; size -= 2;
 306                                 lpnum--;
 307                         }
 308                         switch(shift) {
 309                         case 0xc:
 310                                 idx = MMU_PAGE_4K;
 311                                 break;
 312                         case 0x10:
 313                                 idx = MMU_PAGE_64K;
 314                                 break;
 315                         case 0x14:
 316                                 idx = MMU_PAGE_1M;
 317                                 break;
 318                         case 0x18:
 319                                 idx = MMU_PAGE_16M;
 320                                 cur_cpu_spec->mmu_features |= MMU_FTR_16M_PAGE;
 321                                 break;
 322                         case 0x22:
 323                                 idx = MMU_PAGE_16G;
 324                                 break;
 325                         }
 326                         if (idx < 0)
 327                                 continue;
 328                         def = &mmu_psize_defs[idx];
 329                         def->shift = shift;
 330                         if (shift <= 23)
 331                                 def->avpnm = 0;
 332                         else
 333                                 def->avpnm = (1 << (shift - 23)) - 1;
 334                         def->sllp = slbenc;
 335                         def->penc = lpenc;
 336                         /* We don't know for sure what's up with tlbiel, so
 337                          * for now we only set it for 4K and 64K pages
 338                          */
 339                         if (idx == MMU_PAGE_4K || idx == MMU_PAGE_64K)
 340                                 def->tlbiel = 1;
 341                         else
 342                                 def->tlbiel = 0;
 343
 344                         DBG(" %d: shift=%02x, sllp=%04lx, avpnm=%08lx, "
 345                             "tlbiel=%d, penc=%d\n",
 346                             idx, shift, def->sllp, def->avpnm, def->tlbiel,
 347                             def->penc);
 348                 }
 349                 return 1;
 350         }
 351         return 0;
 352 }
 353
 354 #ifdef CONFIG_HUGETLB_PAGE
 355 /* Scan for 16G memory blocks that have been set aside for huge pages
 356  * and reserve those blocks for 16G huge pages.
 357  */
 358 static int __init htab_dt_scan_hugepage_blocks(unsigned long node,
 359                                         const char *uname, int depth,
 360                                         void *data) {
 361         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 362         unsigned long *addr_prop;
 363         u32 *page_count_prop;
 364         unsigned int expected_pages;
 365         long unsigned int phys_addr;
 366         long unsigned int block_size;
 367
 368         /* We are scanning "memory" nodes only */
 369         if (type == NULL || strcmp(type, "memory") != 0)
 370                 return 0;
 371
 372         /* This property is the log base 2 of the number of virtual pages that
 373          * will represent this memory block. */
 374         page_count_prop = of_get_flat_dt_prop(node, "ibm,expected#pages", NULL);
 375         if (page_count_prop == NULL)
 376                 return 0;
 377         expected_pages = (1 << page_count_prop[0]);
 378         addr_prop = of_get_flat_dt_prop(node, "reg", NULL);
 379         if (addr_prop == NULL)
 380                 return 0;
 381         phys_addr = addr_prop[0];
 382         block_size = addr_prop[1];
 383         if (block_size != (16 * GB))
 384                 return 0;
 385         printk(KERN_INFO "Huge page(16GB) memory: "
 386                         "addr = 0x%lX size = 0x%lX pages = %d\n",
 387                         phys_addr, block_size, expected_pages);
 388         if (phys_addr + (16 * GB) <= memblock_end_of_DRAM()) {
 389                 memblock_reserve(phys_addr, block_size * expected_pages);
 390                 add_gpage(phys_addr, block_size, expected_pages);
 391         }
 392         return 0;
 393 }
 394 #endif /* CONFIG_HUGETLB_PAGE */
 395
 396 static void __init htab_init_page_sizes(void)
 397 {
 398         int rc;
 399
 400         /* Default to 4K pages only */
 401         memcpy(mmu_psize_defs, mmu_psize_defaults_old,
 402                sizeof(mmu_psize_defaults_old));
 403
 404         /*
 405          * Try to find the available page sizes in the device-tree
 406          */
 407         rc = of_scan_flat_dt(htab_dt_scan_page_sizes, NULL);
 408         if (rc != 0)  /* Found */
 409                 goto found;
 410
 411         /*
 412          * Not in the device-tree, let's fallback on known size
 413          * list for 16M capable GP & GR
 414          */
 415         if (mmu_has_feature(MMU_FTR_16M_PAGE))
 416                 memcpy(mmu_psize_defs, mmu_psize_defaults_gp,
 417                        sizeof(mmu_psize_defaults_gp));
 418  found:
 419 #ifndef CONFIG_DEBUG_PAGEALLOC
 420         /*
 421          * Pick a size for the linear mapping. Currently, we only support
 422          * 16M, 1M and 4K which is the default
 423          */
 424         if (mmu_psize_defs[MMU_PAGE_16M].shift)
 425                 mmu_linear_psize = MMU_PAGE_16M;
 426         else if (mmu_psize_defs[MMU_PAGE_1M].shift)
 427                 mmu_linear_psize = MMU_PAGE_1M;
 428 #endif /* CONFIG_DEBUG_PAGEALLOC */
 429
 430 #ifdef CONFIG_PPC_64K_PAGES
 431         /*
 432          * Pick a size for the ordinary pages. Default is 4K, we support
 433          * 64K for user mappings and vmalloc if supported by the processor.
 434          * We only use 64k for ioremap if the processor
 435          * (and firmware) support cache-inhibited large pages.
 436          * If not, we use 4k and set mmu_ci_restrictions so that
 437          * hash_page knows to switch processes that use cache-inhibited
 438          * mappings to 4k pages.
 439          */
 440         if (mmu_psize_defs[MMU_PAGE_64K].shift) {
 441                 mmu_virtual_psize = MMU_PAGE_64K;
 442                 mmu_vmalloc_psize = MMU_PAGE_64K;
 443                 if (mmu_linear_psize == MMU_PAGE_4K)
 444                         mmu_linear_psize = MMU_PAGE_64K;
 445                 if (mmu_has_feature(MMU_FTR_CI_LARGE_PAGE)) {
 446                         /*
 447                          * Don't use 64k pages for ioremap on pSeries, since
 448                          * that would stop us accessing the HEA ethernet.
 449                          */
 450                         if (!machine_is(pseries))
 451                                 mmu_io_psize = MMU_PAGE_64K;
 452                 } else
 453                         mmu_ci_restrictions = 1;
 454         }
 455 #endif /* CONFIG_PPC_64K_PAGES */
 456
 457 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 458         /* We try to use 16M pages for vmemmap if that is supported
 459          * and we have at least 1G of RAM at boot
 460          */
 461         if (mmu_psize_defs[MMU_PAGE_16M].shift &&
 462             memblock_phys_mem_size() >= 0x40000000)
 463                 mmu_vmemmap_psize = MMU_PAGE_16M;
 464         else if (mmu_psize_defs[MMU_PAGE_64K].shift)
 465                 mmu_vmemmap_psize = MMU_PAGE_64K;
 466         else
 467                 mmu_vmemmap_psize = MMU_PAGE_4K;
 468 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 469
 470         printk(KERN_DEBUG "Page orders: linear mapping = %d, "
 471                "virtual = %d, io = %d"
 472 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 473                ", vmemmap = %d"
 474 #endif
 475                "\n",
 476                mmu_psize_defs[mmu_linear_psize].shift,
 477                mmu_psize_defs[mmu_virtual_psize].shift,
 478                mmu_psize_defs[mmu_io_psize].shift
 479 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 480                ,mmu_psize_defs[mmu_vmemmap_psize].shift
 481 #endif
 482                );
 483
 484 #ifdef CONFIG_HUGETLB_PAGE
 485         /* Reserve 16G huge page memory sections for huge pages */
 486         of_scan_flat_dt(htab_dt_scan_hugepage_blocks, NULL);
 487 #endif /* CONFIG_HUGETLB_PAGE */
 488 }
 489
 490 static int __init htab_dt_scan_pftsize(unsigned long node,
 491                                        const char *uname, int depth,
 492                                        void *data)
 493 {
 494         char *type = of_get_flat_dt_prop(node, "device_type", NULL);
 495         u32 *prop;
 496
 497         /* We are scanning "cpu" nodes only */
 498         if (type == NULL || strcmp(type, "cpu") != 0)
 499                 return 0;
 500
 501         prop = (u32 *)of_get_flat_dt_prop(node, "ibm,pft-size", NULL);
 502         if (prop != NULL) {
 503                 /* pft_size[0] is the NUMA CEC cookie */
 504                 ppc64_pft_size = prop[1];
 505                 return 1;
 506         }
 507         return 0;
 508 }
 509
 510 static unsigned long __init htab_get_table_size(void)
 511 {
 512         unsigned long mem_size, rnd_mem_size, pteg_count, psize;
 513
 514         /* If hash size isn't already provided by the platform, we try to
 515          * retrieve it from the device-tree. If it's not there neither, we
 516          * calculate it now based on the total RAM size
 517          */
 518         if (ppc64_pft_size == 0)
 519                 of_scan_flat_dt(htab_dt_scan_pftsize, NULL);
 520         if (ppc64_pft_size)
 521                 return 1UL << ppc64_pft_size;
 522
 523         /* round mem_size up to next power of 2 */
 524         mem_size = memblock_phys_mem_size();
 525         rnd_mem_size = 1UL << __ilog2(mem_size);
 526         if (rnd_mem_size < mem_size)
 527                 rnd_mem_size <<= 1;
 528
 529         /* # pages / 2 */
 530         psize = mmu_psize_defs[mmu_virtual_psize].shift;
 531         pteg_count = max(rnd_mem_size >> (psize + 1), 1UL << 11);
 532
 533         return pteg_count << 7;
 534 }
 535
 536 #ifdef CONFIG_MEMORY_HOTPLUG
 537 int create_section_mapping(unsigned long start, unsigned long end)
 538 {
 539         return htab_bolt_mapping(start, end, __pa(start),
 540                                  pgprot_val(PAGE_KERNEL), mmu_linear_psize,
 541                                  mmu_kernel_ssize);
 542 }
 543
 544 int remove_section_mapping(unsigned long start, unsigned long end)
 545 {
 546         return htab_remove_mapping(start, end, mmu_linear_psize,
 547                         mmu_kernel_ssize);
 548 }
 549 #endif /* CONFIG_MEMORY_HOTPLUG */
 550
 551 #define FUNCTION_TEXT(A)        ((*(unsigned long *)(A)))
 552
 553 static void __init htab_finish_init(void)
 554 {
 555         extern unsigned int *htab_call_hpte_insert1;
 556         extern unsigned int *htab_call_hpte_insert2;
 557         extern unsigned int *htab_call_hpte_remove;
 558         extern unsigned int *htab_call_hpte_updatepp;
 559
 560 #ifdef CONFIG_PPC_HAS_HASH_64K
 561         extern unsigned int *ht64_call_hpte_insert1;
 562         extern unsigned int *ht64_call_hpte_insert2;
 563         extern unsigned int *ht64_call_hpte_remove;
 564         extern unsigned int *ht64_call_hpte_updatepp;
 565
 566         patch_branch(ht64_call_hpte_insert1,
 567                 FUNCTION_TEXT(ppc_md.hpte_insert),
 568                 BRANCH_SET_LINK);
 569         patch_branch(ht64_call_hpte_insert2,
 570                 FUNCTION_TEXT(ppc_md.hpte_insert),
 571                 BRANCH_SET_LINK);
 572         patch_branch(ht64_call_hpte_remove,
 573                 FUNCTION_TEXT(ppc_md.hpte_remove),
 574                 BRANCH_SET_LINK);
 575         patch_branch(ht64_call_hpte_updatepp,
 576                 FUNCTION_TEXT(ppc_md.hpte_updatepp),
 577                 BRANCH_SET_LINK);
 578
 579 #endif /* CONFIG_PPC_HAS_HASH_64K */
 580
 581         patch_branch(htab_call_hpte_insert1,
 582                 FUNCTION_TEXT(ppc_md.hpte_insert),
 583                 BRANCH_SET_LINK);
 584         patch_branch(htab_call_hpte_insert2,
 585                 FUNCTION_TEXT(ppc_md.hpte_insert),
 586                 BRANCH_SET_LINK);
 587         patch_branch(htab_call_hpte_remove,
 588                 FUNCTION_TEXT(ppc_md.hpte_remove),
 589                 BRANCH_SET_LINK);
 590         patch_branch(htab_call_hpte_updatepp,
 591                 FUNCTION_TEXT(ppc_md.hpte_updatepp),
 592                 BRANCH_SET_LINK);
 593 }
 594
 595 static void __init htab_initialize(void)
 596 {
 597         unsigned long table;
 598         unsigned long pteg_count;
 599         unsigned long prot;
 600         unsigned long base = 0, size = 0, limit;
 601         struct memblock_region *reg;
 602
 603         DBG(" -> htab_initialize()\n");
 604
 605         /* Initialize segment sizes */
 606         htab_init_seg_sizes();
 607
 608         /* Initialize page sizes */
 609         htab_init_page_sizes();
 610
 611         if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) {
 612                 mmu_kernel_ssize = MMU_SEGSIZE_1T;
 613                 mmu_highuser_ssize = MMU_SEGSIZE_1T;
 614                 printk(KERN_INFO "Using 1TB segments\n");
 615         }
 616
 617         /*
 618          * Calculate the required size of the htab.  We want the number of
 619          * PTEGs to equal one half the number of real pages.
 620          */
 621         htab_size_bytes = htab_get_table_size();
 622         pteg_count = htab_size_bytes >> 7;
 623
 624         htab_hash_mask = pteg_count - 1;
 625
 626         if (firmware_has_feature(FW_FEATURE_LPAR)) {
 627                 /* Using a hypervisor which owns the htab */
 628                 htab_address = NULL;
 629                 _SDR1 = 0;
 630 #ifdef CONFIG_FA_DUMP
 631                 /*
 632                  * If firmware assisted dump is active firmware preserves
 633                  * the contents of htab along with entire partition memory.
 634                  * Clear the htab if firmware assisted dump is active so
 635                  * that we dont end up using old mappings.
 636                  */
 637                 if (is_fadump_active() && ppc_md.hpte_clear_all)
 638                         ppc_md.hpte_clear_all();
 639 #endif
 640         } else {
 641                 /* Find storage for the HPT.  Must be contiguous in
 642                  * the absolute address space. On cell we want it to be
 643                  * in the first 2 Gig so we can use it for IOMMU hacks.
 644                  */
 645                 if (machine_is(cell))
 646                         limit = 0x80000000;
 647                 else
 648                         limit = MEMBLOCK_ALLOC_ANYWHERE;
 649
 650                 table = memblock_alloc_base(htab_size_bytes, htab_size_bytes, limit);
 651
 652                 DBG("Hash table allocated at %lx, size: %lx\n", table,
 653                     htab_size_bytes);
 654
 655                 htab_address = abs_to_virt(table);
 656
 657                 /* htab absolute addr + encoded htabsize */
 658                 _SDR1 = table + __ilog2(pteg_count) - 11;
 659
 660                 /* Initialize the HPT with no entries */
 661                 memset((void *)table, 0, htab_size_bytes);
 662
 663                 /* Set SDR1 */
 664                 mtspr(SPRN_SDR1, _SDR1);
 665         }
 666
 667         prot = pgprot_val(PAGE_KERNEL);
 668
 669 #ifdef CONFIG_DEBUG_PAGEALLOC
 670         linear_map_hash_count = memblock_end_of_DRAM() >> PAGE_SHIFT;
 671         linear_map_hash_slots = __va(memblock_alloc_base(linear_map_hash_count,
 672                                                     1, ppc64_rma_size));
 673         memset(linear_map_hash_slots, 0, linear_map_hash_count);
 674 #endif /* CONFIG_DEBUG_PAGEALLOC */
 675
 676         /* On U3 based machines, we need to reserve the DART area and
 677          * _NOT_ map it to avoid cache paradoxes as it's remapped non
 678          * cacheable later on
 679          */
 680
 681         /* create bolted the linear mapping in the hash table */
 682         for_each_memblock(memory, reg) {
 683                 base = (unsigned long)__va(reg->base);
 684                 size = reg->size;
 685
 686                 DBG("creating mapping for region: %lx..%lx (prot: %lx)\n",
 687                     base, size, prot);
 688
 689 #ifdef CONFIG_U3_DART
 690                 /* Do not map the DART space. Fortunately, it will be aligned
 691                  * in such a way that it will not cross two memblock regions and
 692                  * will fit within a single 16Mb page.
 693                  * The DART space is assumed to be a full 16Mb region even if
 694                  * we only use 2Mb of that space. We will use more of it later
 695                  * for AGP GART. We have to use a full 16Mb large page.
 696                  */
 697                 DBG("DART base: %lx\n", dart_tablebase);
 698
 699                 if (dart_tablebase != 0 && dart_tablebase >= base
 700                     && dart_tablebase < (base + size)) {
 701                         unsigned long dart_table_end = dart_tablebase + 16 * MB;
 702                         if (base != dart_tablebase)
 703                                 BUG_ON(htab_bolt_mapping(base, dart_tablebase,
 704                                                         __pa(base), prot,
 705                                                         mmu_linear_psize,
 706                                                         mmu_kernel_ssize));
 707                         if ((base + size) > dart_table_end)
 708                                 BUG_ON(htab_bolt_mapping(dart_tablebase+16*MB,
 709                                                         base + size,
 710                                                         __pa(dart_table_end),
 711                                                          prot,
 712                                                          mmu_linear_psize,
 713                                                          mmu_kernel_ssize));
 714                         continue;
 715                 }
 716 #endif /* CONFIG_U3_DART */
 717                 BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
 718                                 prot, mmu_linear_psize, mmu_kernel_ssize));
 719         }
 720         memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
 721
 722         /*
 723          * If we have a memory_limit and we've allocated TCEs then we need to
 724          * explicitly map the TCE area at the top of RAM. We also cope with the
 725          * case that the TCEs start below memory_limit.
 726          * tce_alloc_start/end are 16MB aligned so the mapping should work
 727          * for either 4K or 16MB pages.
 728          */
 729         if (tce_alloc_start) {
 730                 tce_alloc_start = (unsigned long)__va(tce_alloc_start);
 731                 tce_alloc_end = (unsigned long)__va(tce_alloc_end);
 732
 733                 if (base + size >= tce_alloc_start)
 734                         tce_alloc_start = base + size + 1;
 735
 736                 BUG_ON(htab_bolt_mapping(tce_alloc_start, tce_alloc_end,
 737                                          __pa(tce_alloc_start), prot,
 738                                          mmu_linear_psize, mmu_kernel_ssize));
 739         }
 740
 741         htab_finish_init();
 742
 743         DBG(" <- htab_initialize()\n");
 744 }
 745 #undef KB
 746 #undef MB
 747
 748 void __init early_init_mmu(void)
 749 {
 750         /* Setup initial STAB address in the PACA */
 751         get_paca()->stab_real = __pa((u64)&initial_stab);
 752         get_paca()->stab_addr = (u64)&initial_stab;
 753
 754         /* Initialize the MMU Hash table and create the linear mapping
 755          * of memory. Has to be done before stab/slb initialization as
 756          * this is currently where the page size encoding is obtained
 757          */
 758         htab_initialize();
 759
 760         /* Initialize stab / SLB management */
 761         if (mmu_has_feature(MMU_FTR_SLB))
 762                 slb_initialize();
 763 }
 764
 765 #ifdef CONFIG_SMP
 766 void __cpuinit early_init_mmu_secondary(void)
 767 {
 768         /* Initialize hash table for that CPU */
 769         if (!firmware_has_feature(FW_FEATURE_LPAR))
 770                 mtspr(SPRN_SDR1, _SDR1);
 771
 772         /* Initialize STAB/SLB. We use a virtual address as it works
 773          * in real mode on pSeries.
 774          */
 775         if (mmu_has_feature(MMU_FTR_SLB))
 776                 slb_initialize();
 777         else
 778                 stab_initialize(get_paca()->stab_addr);
 779 }
 780 #endif /* CONFIG_SMP */
 781
 782 /*
 783  * Called by asm hashtable.S for doing lazy icache flush
 784  */
 785 unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)
 786 {
 787         struct page *page;
 788
 789         if (!pfn_valid(pte_pfn(pte)))
 790                 return pp;
 791
 792         page = pte_page(pte);
 793
 794         /* page is dirty */
 795         if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
 796                 if (trap == 0x400) {
 797                         flush_dcache_icache_page(page);
 798                         set_bit(PG_arch_1, &page->flags);
 799                 } else
 800                         pp |= HPTE_R_N;
 801         }
 802         return pp;
 803 }
 804
 805 #ifdef CONFIG_PPC_MM_SLICES
 806 unsigned int get_paca_psize(unsigned long addr)
 807 {
 808         unsigned long index, slices;
 809
 810         if (addr < SLICE_LOW_TOP) {
 811                 slices = get_paca()->context.low_slices_psize;
 812                 index = GET_LOW_SLICE_INDEX(addr);
 813         } else {
 814                 slices = get_paca()->context.high_slices_psize;
 815                 index = GET_HIGH_SLICE_INDEX(addr);
 816         }
 817         return (slices >> (index * 4)) & 0xF;
 818 }
 819
 820 #else
 821 unsigned int get_paca_psize(unsigned long addr)
 822 {
 823         return get_paca()->context.user_psize;
 824 }
 825 #endif
 826
 827 /*
 828  * Demote a segment to using 4k pages.
 829  * For now this makes the whole process use 4k pages.
 830  */
 831 #ifdef CONFIG_PPC_64K_PAGES
 832 void demote_segment_4k(struct mm_struct *mm, unsigned long addr)
 833 {
 834         if (get_slice_psize(mm, addr) == MMU_PAGE_4K)
 835                 return;
 836         slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K);
 837 #ifdef CONFIG_SPU_BASE
 838         spu_flush_all_slbs(mm);
 839 #endif
 840         if (get_paca_psize(addr) != MMU_PAGE_4K) {
 841                 get_paca()->context = mm->context;
 842                 slb_flush_and_rebolt();
 843         }
 844 }
 845 #endif /* CONFIG_PPC_64K_PAGES */
 846
 847 #ifdef CONFIG_PPC_SUBPAGE_PROT
 848 /*
 849  * This looks up a 2-bit protection code for a 4k subpage of a 64k page.
 850  * Userspace sets the subpage permissions using the subpage_prot system call.
 851  *
 852  * Result is 0: full permissions, _PAGE_RW: read-only,
 853  * _PAGE_USER or _PAGE_USER|_PAGE_RW: no access.
 854  */
 855 static int subpage_protection(struct mm_struct *mm, unsigned long ea)
 856 {
 857         struct subpage_prot_table *spt = &mm->context.spt;
 858         u32 spp = 0;
 859         u32 **sbpm, *sbpp;
 860
 861         if (ea >= spt->maxaddr)
 862                 return 0;
 863         if (ea < 0x100000000) {
 864                 /* addresses below 4GB use spt->low_prot */
 865                 sbpm = spt->low_prot;
 866         } else {
 867                 sbpm = spt->protptrs[ea >> SBP_L3_SHIFT];
 868                 if (!sbpm)
 869                         return 0;
 870         }
 871         sbpp = sbpm[(ea >> SBP_L2_SHIFT) & (SBP_L2_COUNT - 1)];
 872         if (!sbpp)
 873                 return 0;
 874         spp = sbpp[(ea >> PAGE_SHIFT) & (SBP_L1_COUNT - 1)];
 875
 876         /* extract 2-bit bitfield for this 4k subpage */
 877         spp >>= 30 - 2 * ((ea >> 12) & 0xf);
 878
 879         /* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */
 880         spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0);
 881         return spp;
 882 }
 883
 884 #else /* CONFIG_PPC_SUBPAGE_PROT */
 885 static inline int subpage_protection(struct mm_struct *mm, unsigned long ea)
 886 {
 887         return 0;
 888 }
 889 #endif
 890
 891 void hash_failure_debug(unsigned long ea, unsigned long access,
 892                         unsigned long vsid, unsigned long trap,
 893                         int ssize, int psize, unsigned long pte)
 894 {
 895         if (!printk_ratelimit())
 896                 return;
 897         pr_info("mm: Hashing failure ! EA=0x%lx access=0x%lx current=%s\n",
 898                 ea, access, current->comm);
 899         pr_info("    trap=0x%lx vsid=0x%lx ssize=%d psize=%d pte=0x%lx\n",
 900                 trap, vsid, ssize, psize, pte);
 901 }
 902
 903 /* Result code is:
 904  *  0 - handled
 905  *  1 - normal page fault
 906  * -1 - critical hash insertion error
 907  * -2 - access not permitted by subpage protection mechanism
 908  */
 909 int hash_page(unsigned long ea, unsigned long access, unsigned long trap)
 910 {
 911         pgd_t *pgdir;
 912         unsigned long vsid;
 913         struct mm_struct *mm;
 914         pte_t *ptep;
 915         unsigned hugeshift;
 916         const struct cpumask *tmp;
 917         int rc, user_region = 0, local = 0;
 918         int psize, ssize;
 919
 920         DBG_LOW("hash_page(ea=%016lx, access=%lx, trap=%lx\n",
 921                 ea, access, trap);
 922
 923         if ((ea & ~REGION_MASK) >= PGTABLE_RANGE) {
 924                 DBG_LOW(" out of pgtable range !\n");
 925                 return 1;
 926         }
 927
 928         /* Get region & vsid */
 929         switch (REGION_ID(ea)) {
 930         case USER_REGION_ID:
 931                 user_region = 1;
 932                 mm = current->mm;
 933                 if (! mm) {
 934                         DBG_LOW(" user region with no mm !\n");
 935                         return 1;
 936                 }
 937                 psize = get_slice_psize(mm, ea);
 938                 ssize = user_segment_size(ea);
 939                 vsid = get_vsid(mm->context.id, ea, ssize);
 940                 break;
 941         case VMALLOC_REGION_ID:
 942                 mm = &init_mm;
 943                 vsid = get_kernel_vsid(ea, mmu_kernel_ssize);
 944                 if (ea < VMALLOC_END)
 945                         psize = mmu_vmalloc_psize;
 946                 else
 947                         psize = mmu_io_psize;
 948                 ssize = mmu_kernel_ssize;
 949                 break;
 950         default:
 951                 /* Not a valid range
 952                  * Send the problem up to do_page_fault
 953                  */
 954                 return 1;
 955         }
 956         DBG_LOW(" mm=%p, mm->pgdir=%p, vsid=%016lx\n", mm, mm->pgd, vsid);
 957
 958         /* Get pgdir */
 959         pgdir = mm->pgd;
 960         if (pgdir == NULL)
 961                 return 1;
 962
 963         /* Check CPU locality */
 964         tmp = cpumask_of(smp_processor_id());
 965         if (user_region && cpumask_equal(mm_cpumask(mm), tmp))
 966                 local = 1;
 967
 968 #ifndef CONFIG_PPC_64K_PAGES
 969         /* If we use 4K pages and our psize is not 4K, then we might
 970          * be hitting a special driver mapping, and need to align the
 971          * address before we fetch the PTE.
 972          *
 973          * It could also be a hugepage mapping, in which case this is
 974          * not necessary, but it's not harmful, either.
 975          */
 976         if (psize != MMU_PAGE_4K)
 977                 ea &= ~((1ul << mmu_psize_defs[psize].shift) - 1);
 978 #endif /* CONFIG_PPC_64K_PAGES */
 979
 980         /* Get PTE and page size from page tables */
 981         ptep = find_linux_pte_or_hugepte(pgdir, ea, &hugeshift);
 982         if (ptep == NULL || !pte_present(*ptep)) {
 983                 DBG_LOW(" no PTE !\n");
 984                 return 1;
 985         }
 986
 987         /* Add _PAGE_PRESENT to the required access perm */
 988         access |= _PAGE_PRESENT;
 989
 990         /* Pre-check access permissions (will be re-checked atomically
 991          * in __hash_page_XX but this pre-check is a fast path
 992          */
 993         if (access & ~pte_val(*ptep)) {
 994                 DBG_LOW(" no access !\n");
 995                 return 1;
 996         }
 997
 998 #ifdef CONFIG_HUGETLB_PAGE
 999         if (hugeshift)
1000                 return __hash_page_huge(ea, access, vsid, ptep, trap, local,
1001                                         ssize, hugeshift, psize);
1002 #endif /* CONFIG_HUGETLB_PAGE */
1003
1004 #ifndef CONFIG_PPC_64K_PAGES
1005         DBG_LOW(" i-pte: %016lx\n", pte_val(*ptep));
1006 #else
1007         DBG_LOW(" i-pte: %016lx %016lx\n", pte_val(*ptep),
1008                 pte_val(*(ptep + PTRS_PER_PTE)));
1009 #endif
1010         /* Do actual hashing */
1011 #ifdef CONFIG_PPC_64K_PAGES
1012         /* If _PAGE_4K_PFN is set, make sure this is a 4k segment */
1013         if ((pte_val(*ptep) & _PAGE_4K_PFN) && psize == MMU_PAGE_64K) {
1014                 demote_segment_4k(mm, ea);
1015                 psize = MMU_PAGE_4K;
1016         }
1017
1018         /* If this PTE is non-cacheable and we have restrictions on
1019          * using non cacheable large pages, then we switch to 4k
1020          */
1021         if (mmu_ci_restrictions && psize == MMU_PAGE_64K &&
1022             (pte_val(*ptep) & _PAGE_NO_CACHE)) {
1023                 if (user_region) {
1024                         demote_segment_4k(mm, ea);
1025                         psize = MMU_PAGE_4K;
1026                 } else if (ea < VMALLOC_END) {
1027                         /*
1028                          * some driver did a non-cacheable mapping
1029                          * in vmalloc space, so switch vmalloc
1030                          * to 4k pages
1031                          */
1032                         printk(KERN_ALERT "Reducing vmalloc segment "
1033                                "to 4kB pages because of "
1034                                "non-cacheable mapping\n");
1035                         psize = mmu_vmalloc_psize = MMU_PAGE_4K;
1036 #ifdef CONFIG_SPU_BASE
1037                         spu_flush_all_slbs(mm);
1038 #endif
1039                 }
1040         }
1041         if (user_region) {
1042                 if (psize != get_paca_psize(ea)) {
1043                         get_paca()->context = mm->context;
1044                         slb_flush_and_rebolt();
1045                 }
1046         } else if (get_paca()->vmalloc_sllp !=
1047                    mmu_psize_defs[mmu_vmalloc_psize].sllp) {
1048                 get_paca()->vmalloc_sllp =
1049                         mmu_psize_defs[mmu_vmalloc_psize].sllp;
1050                 slb_vmalloc_update();
1051         }
1052 #endif /* CONFIG_PPC_64K_PAGES */
1053
1054 #ifdef CONFIG_PPC_HAS_HASH_64K
1055         if (psize == MMU_PAGE_64K)
1056                 rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
1057         else
1058 #endif /* CONFIG_PPC_HAS_HASH_64K */
1059         {
1060                 int spp = subpage_protection(mm, ea);
1061                 if (access & spp)
1062                         rc = -2;
1063                 else
1064                         rc = __hash_page_4K(ea, access, vsid, ptep, trap,
1065                                             local, ssize, spp);
1066         }
1067
1068         /* Dump some info in case of hash insertion failure, they should
1069          * never happen so it is really useful to know if/when they do
1070          */
1071         if (rc == -1)
1072                 hash_failure_debug(ea, access, vsid, trap, ssize, psize,
1073                                    pte_val(*ptep));
1074 #ifndef CONFIG_PPC_64K_PAGES
1075         DBG_LOW(" o-pte: %016lx\n", pte_val(*ptep));
1076 #else
1077         DBG_LOW(" o-pte: %016lx %016lx\n", pte_val(*ptep),
1078                 pte_val(*(ptep + PTRS_PER_PTE)));
1079 #endif
1080         DBG_LOW(" -> rc=%d\n", rc);
1081         return rc;
1082 }
1083 EXPORT_SYMBOL_GPL(hash_page);
1084
1085 void hash_preload(struct mm_struct *mm, unsigned long ea,
1086                   unsigned long access, unsigned long trap)
1087 {
1088         unsigned long vsid;
1089         pgd_t *pgdir;
1090         pte_t *ptep;
1091         unsigned long flags;
1092         int rc, ssize, local = 0;
1093
1094         BUG_ON(REGION_ID(ea) != USER_REGION_ID);
1095
1096 #ifdef CONFIG_PPC_MM_SLICES
1097         /* We only prefault standard pages for now */
1098         if (unlikely(get_slice_psize(mm, ea) != mm->context.user_psize))
1099                 return;
1100 #endif
1101
1102         DBG_LOW("hash_preload(mm=%p, mm->pgdir=%p, ea=%016lx, access=%lx,"
1103                 " trap=%lx\n", mm, mm->pgd, ea, access, trap);
1104
1105         /* Get Linux PTE if available */
1106         pgdir = mm->pgd;
1107         if (pgdir == NULL)
1108                 return;
1109         ptep = find_linux_pte(pgdir, ea);
1110         if (!ptep)
1111                 return;
1112
1113 #ifdef CONFIG_PPC_64K_PAGES
1114         /* If either _PAGE_4K_PFN or _PAGE_NO_CACHE is set (and we are on
1115          * a 64K kernel), then we don't preload, hash_page() will take
1116          * care of it once we actually try to access the page.
1117          * That way we don't have to duplicate all of the logic for segment
1118          * page size demotion here
1119          */
1120         if (pte_val(*ptep) & (_PAGE_4K_PFN | _PAGE_NO_CACHE))
1121                 return;
1122 #endif /* CONFIG_PPC_64K_PAGES */
1123
1124         /* Get VSID */
1125         ssize = user_segment_size(ea);
1126         vsid = get_vsid(mm->context.id, ea, ssize);
1127
1128         /* Hash doesn't like irqs */
1129         local_irq_save(flags);
1130
1131         /* Is that local to this CPU ? */
1132         if (cpumask_equal(mm_cpumask(mm), cpumask_of(smp_processor_id())))
1133                 local = 1;
1134
1135         /* Hash it in */
1136 #ifdef CONFIG_PPC_HAS_HASH_64K
1137         if (mm->context.user_psize == MMU_PAGE_64K)
1138                 rc = __hash_page_64K(ea, access, vsid, ptep, trap, local, ssize);
1139         else
1140 #endif /* CONFIG_PPC_HAS_HASH_64K */
1141                 rc = __hash_page_4K(ea, access, vsid, ptep, trap, local, ssize,
1142                                     subpage_protection(mm, ea));
1143
1144         /* Dump some info in case of hash insertion failure, they should
1145          * never happen so it is really useful to know if/when they do
1146          */
1147         if (rc == -1)
1148                 hash_failure_debug(ea, access, vsid, trap, ssize,
1149                                    mm->context.user_psize, pte_val(*ptep));
1150
1151         local_irq_restore(flags);
1152 }
1153
1154 /* WARNING: This is called from hash_low_64.S, if you change this prototype,
1155  *          do not forget to update the assembly call site !
1156  */
1157 void flush_hash_page(unsigned long va, real_pte_t pte, int psize, int ssize,
1158                      int local)
1159 {
1160         unsigned long hash, index, shift, hidx, slot;
1161
1162         DBG_LOW("flush_hash_page(va=%016lx)\n", va);
1163         pte_iterate_hashed_subpages(pte, psize, va, index, shift) {
1164                 hash = hpt_hash(va, shift, ssize);
1165                 hidx = __rpte_to_hidx(pte, index);
1166                 if (hidx & _PTEIDX_SECONDARY)
1167                         hash = ~hash;
1168                 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1169                 slot += hidx & _PTEIDX_GROUP_IX;
1170                 DBG_LOW(" sub %ld: hash=%lx, hidx=%lx\n", index, slot, hidx);
1171                 ppc_md.hpte_invalidate(slot, va, psize, ssize, local);
1172         } pte_iterate_hashed_end();
1173 }
1174
1175 void flush_hash_range(unsigned long number, int local)
1176 {
1177         if (ppc_md.flush_hash_range)
1178                 ppc_md.flush_hash_range(number, local);
1179         else {
1180                 int i;
1181                 struct ppc64_tlb_batch *batch =
1182                         &__get_cpu_var(ppc64_tlb_batch);
1183
1184                 for (i = 0; i < number; i++)
1185                         flush_hash_page(batch->vaddr[i], batch->pte[i],
1186                                         batch->psize, batch->ssize, local);
1187         }
1188 }
1189
1190 /*
1191  * low_hash_fault is called when we the low level hash code failed
1192  * to instert a PTE due to an hypervisor error
1193  */
1194 void low_hash_fault(struct pt_regs *regs, unsigned long address, int rc)
1195 {
1196         if (user_mode(regs)) {
1197 #ifdef CONFIG_PPC_SUBPAGE_PROT
1198                 if (rc == -2)
1199                         _exception(SIGSEGV, regs, SEGV_ACCERR, address);
1200                 else
1201 #endif
1202                         _exception(SIGBUS, regs, BUS_ADRERR, address);
1203         } else
1204                 bad_page_fault(regs, address, SIGBUS);
1205 }
1206
1207 #ifdef CONFIG_DEBUG_PAGEALLOC
1208 static void kernel_map_linear_page(unsigned long vaddr, unsigned long lmi)
1209 {
1210         unsigned long hash, hpteg;
1211         unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1212         unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize);
1213         unsigned long mode = htab_convert_pte_flags(PAGE_KERNEL);
1214         int ret;
1215
1216         hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize);
1217         hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP);
1218
1219         ret = ppc_md.hpte_insert(hpteg, va, __pa(vaddr),
1220                                  mode, HPTE_V_BOLTED,
1221                                  mmu_linear_psize, mmu_kernel_ssize);
1222         BUG_ON (ret < 0);
1223         spin_lock(&linear_map_hash_lock);
1224         BUG_ON(linear_map_hash_slots[lmi] & 0x80);
1225         linear_map_hash_slots[lmi] = ret | 0x80;
1226         spin_unlock(&linear_map_hash_lock);
1227 }
1228
1229 static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi)
1230 {
1231         unsigned long hash, hidx, slot;
1232         unsigned long vsid = get_kernel_vsid(vaddr, mmu_kernel_ssize);
1233         unsigned long va = hpt_va(vaddr, vsid, mmu_kernel_ssize);
1234
1235         hash = hpt_hash(va, PAGE_SHIFT, mmu_kernel_ssize);
1236         spin_lock(&linear_map_hash_lock);
1237         BUG_ON(!(linear_map_hash_slots[lmi] & 0x80));
1238         hidx = linear_map_hash_slots[lmi] & 0x7f;
1239         linear_map_hash_slots[lmi] = 0;
1240         spin_unlock(&linear_map_hash_lock);
1241         if (hidx & _PTEIDX_SECONDARY)
1242                 hash = ~hash;
1243         slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
1244         slot += hidx & _PTEIDX_GROUP_IX;
1245         ppc_md.hpte_invalidate(slot, va, mmu_linear_psize, mmu_kernel_ssize, 0);
1246 }
1247
1248 void kernel_map_pages(struct page *page, int numpages, int enable)
1249 {
1250         unsigned long flags, vaddr, lmi;
1251         int i;
1252
1253         local_irq_save(flags);
1254         for (i = 0; i < numpages; i++, page++) {
1255                 vaddr = (unsigned long)page_address(page);
1256                 lmi = __pa(vaddr) >> PAGE_SHIFT;
1257                 if (lmi >= linear_map_hash_count)
1258                         continue;
1259                 if (enable)
1260                         kernel_map_linear_page(vaddr, lmi);
1261                 else
1262                         kernel_unmap_linear_page(vaddr, lmi);
1263         }
1264         local_irq_restore(flags);
1265 }
1266 #endif /* CONFIG_DEBUG_PAGEALLOC */
1267
1268 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
1269                                 phys_addr_t first_memblock_size)
1270 {
1271         /* We don't currently support the first MEMBLOCK not mapping 0
1272          * physical on those processors
1273          */
1274         BUG_ON(first_memblock_base != 0);
1275
1276         /* On LPAR systems, the first entry is our RMA region,
1277          * non-LPAR 64-bit hash MMU systems don't have a limitation
1278          * on real mode access, but using the first entry works well
1279          * enough. We also clamp it to 1G to avoid some funky things
1280          * such as RTAS bugs etc...
1281          */
1282         ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
1283
1284         /* Finally limit subsequent allocations */
1285         memblock_set_current_limit(ppc64_rma_size);
1286 }