arch/sh/mm/pmb.c

   1 /*
   2  * arch/sh/mm/pmb.c
   3  *
   4  * Privileged Space Mapping Buffer (PMB) Support.
   5  *
   6  * Copyright (C) 2005 - 2011  Paul Mundt
   7  * Copyright (C) 2010  Matt Fleming
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/syscore_ops.h>
  16 #include <linux/cpu.h>
  17 #include <linux/module.h>
  18 #include <linux/bitops.h>
  19 #include <linux/debugfs.h>
  20 #include <linux/fs.h>
  21 #include <linux/seq_file.h>
  22 #include <linux/err.h>
  23 #include <linux/io.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/vmalloc.h>
  26 #include <asm/cacheflush.h>
  27 #include <asm/sizes.h>
  28 #include <linux/uaccess.h>
  29 #include <asm/pgtable.h>
  30 #include <asm/page.h>
  31 #include <asm/mmu.h>
  32 #include <asm/mmu_context.h>
  33
  34 struct pmb_entry;
  35
  36 struct pmb_entry {
  37         unsigned long vpn;
  38         unsigned long ppn;
  39         unsigned long flags;
  40         unsigned long size;
  41
  42         raw_spinlock_t lock;
  43
  44         /*
  45          * 0 .. NR_PMB_ENTRIES for specific entry selection, or
  46          * PMB_NO_ENTRY to search for a free one
  47          */
  48         int entry;
  49
  50         /* Adjacent entry link for contiguous multi-entry mappings */
  51         struct pmb_entry *link;
  52 };
  53
  54 static struct {
  55         unsigned long size;
  56         int flag;
  57 } pmb_sizes[] = {
  58         { .size = SZ_512M, .flag = PMB_SZ_512M, },
  59         { .size = SZ_128M, .flag = PMB_SZ_128M, },
  60         { .size = SZ_64M,  .flag = PMB_SZ_64M,  },
  61         { .size = SZ_16M,  .flag = PMB_SZ_16M,  },
  62 };
  63
  64 static void pmb_unmap_entry(struct pmb_entry *, int depth);
  65
  66 static DEFINE_RWLOCK(pmb_rwlock);
  67 static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES];
  68 static DECLARE_BITMAP(pmb_map, NR_PMB_ENTRIES);
  69
  70 static unsigned int pmb_iomapping_enabled;
  71
  72 static __always_inline unsigned long mk_pmb_entry(unsigned int entry)
  73 {
  74         return (entry & PMB_E_MASK) << PMB_E_SHIFT;
  75 }
  76
  77 static __always_inline unsigned long mk_pmb_addr(unsigned int entry)
  78 {
  79         return mk_pmb_entry(entry) | PMB_ADDR;
  80 }
  81
  82 static __always_inline unsigned long mk_pmb_data(unsigned int entry)
  83 {
  84         return mk_pmb_entry(entry) | PMB_DATA;
  85 }
  86
  87 static __always_inline unsigned int pmb_ppn_in_range(unsigned long ppn)
  88 {
  89         return ppn >= __pa(memory_start) && ppn < __pa(memory_end);
  90 }
  91
  92 /*
  93  * Ensure that the PMB entries match our cache configuration.
  94  *
  95  * When we are in 32-bit address extended mode, CCR.CB becomes
  96  * invalid, so care must be taken to manually adjust cacheable
  97  * translations.
  98  */
  99 static __always_inline unsigned long pmb_cache_flags(void)
 100 {
 101         unsigned long flags = 0;
 102
 103 #if defined(CONFIG_CACHE_OFF)
 104         flags |= PMB_WT | PMB_UB;
 105 #elif defined(CONFIG_CACHE_WRITETHROUGH)
 106         flags |= PMB_C | PMB_WT | PMB_UB;
 107 #elif defined(CONFIG_CACHE_WRITEBACK)
 108         flags |= PMB_C;
 109 #endif
 110
 111         return flags;
 112 }
 113
 114 /*
 115  * Convert typical pgprot value to the PMB equivalent
 116  */
 117 static inline unsigned long pgprot_to_pmb_flags(pgprot_t prot)
 118 {
 119         unsigned long pmb_flags = 0;
 120         u64 flags = pgprot_val(prot);
 121
 122         if (flags & _PAGE_CACHABLE)
 123                 pmb_flags |= PMB_C;
 124         if (flags & _PAGE_WT)
 125                 pmb_flags |= PMB_WT | PMB_UB;
 126
 127         return pmb_flags;
 128 }
 129
 130 static inline bool pmb_can_merge(struct pmb_entry *a, struct pmb_entry *b)
 131 {
 132         return (b->vpn == (a->vpn + a->size)) &&
 133                (b->ppn == (a->ppn + a->size)) &&
 134                (b->flags == a->flags);
 135 }
 136
 137 static bool pmb_mapping_exists(unsigned long vaddr, phys_addr_t phys,
 138                                unsigned long size)
 139 {
 140         int i;
 141
 142         read_lock(&pmb_rwlock);
 143
 144         for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 145                 struct pmb_entry *pmbe, *iter;
 146                 unsigned long span;
 147
 148                 if (!test_bit(i, pmb_map))
 149                         continue;
 150
 151                 pmbe = &pmb_entry_list[i];
 152
 153                 /*
 154                  * See if VPN and PPN are bounded by an existing mapping.
 155                  */
 156                 if ((vaddr < pmbe->vpn) || (vaddr >= (pmbe->vpn + pmbe->size)))
 157                         continue;
 158                 if ((phys < pmbe->ppn) || (phys >= (pmbe->ppn + pmbe->size)))
 159                         continue;
 160
 161                 /*
 162                  * Now see if we're in range of a simple mapping.
 163                  */
 164                 if (size <= pmbe->size) {
 165                         read_unlock(&pmb_rwlock);
 166                         return true;
 167                 }
 168
 169                 span = pmbe->size;
 170
 171                 /*
 172                  * Finally for sizes that involve compound mappings, walk
 173                  * the chain.
 174                  */
 175                 for (iter = pmbe->link; iter; iter = iter->link)
 176                         span += iter->size;
 177
 178                 /*
 179                  * Nothing else to do if the range requirements are met.
 180                  */
 181                 if (size <= span) {
 182                         read_unlock(&pmb_rwlock);
 183                         return true;
 184                 }
 185         }
 186
 187         read_unlock(&pmb_rwlock);
 188         return false;
 189 }
 190
 191 static bool pmb_size_valid(unsigned long size)
 192 {
 193         int i;
 194
 195         for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
 196                 if (pmb_sizes[i].size == size)
 197                         return true;
 198
 199         return false;
 200 }
 201
 202 static inline bool pmb_addr_valid(unsigned long addr, unsigned long size)
 203 {
 204         return (addr >= P1SEG && (addr + size - 1) < P3SEG);
 205 }
 206
 207 static inline bool pmb_prot_valid(pgprot_t prot)
 208 {
 209         return (pgprot_val(prot) & _PAGE_USER) == 0;
 210 }
 211
 212 static int pmb_size_to_flags(unsigned long size)
 213 {
 214         int i;
 215
 216         for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
 217                 if (pmb_sizes[i].size == size)
 218                         return pmb_sizes[i].flag;
 219
 220         return 0;
 221 }
 222
 223 static int pmb_alloc_entry(void)
 224 {
 225         int pos;
 226
 227         pos = find_first_zero_bit(pmb_map, NR_PMB_ENTRIES);
 228         if (pos >= 0 && pos < NR_PMB_ENTRIES)
 229                 __set_bit(pos, pmb_map);
 230         else
 231                 pos = -ENOSPC;
 232
 233         return pos;
 234 }
 235
 236 static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
 237                                    unsigned long flags, int entry)
 238 {
 239         struct pmb_entry *pmbe;
 240         unsigned long irqflags;
 241         void *ret = NULL;
 242         int pos;
 243
 244         write_lock_irqsave(&pmb_rwlock, irqflags);
 245
 246         if (entry == PMB_NO_ENTRY) {
 247                 pos = pmb_alloc_entry();
 248                 if (unlikely(pos < 0)) {
 249                         ret = ERR_PTR(pos);
 250                         goto out;
 251                 }
 252         } else {
 253                 if (__test_and_set_bit(entry, pmb_map)) {
 254                         ret = ERR_PTR(-ENOSPC);
 255                         goto out;
 256                 }
 257
 258                 pos = entry;
 259         }
 260
 261         write_unlock_irqrestore(&pmb_rwlock, irqflags);
 262
 263         pmbe = &pmb_entry_list[pos];
 264
 265         memset(pmbe, 0, sizeof(struct pmb_entry));
 266
 267         raw_spin_lock_init(&pmbe->lock);
 268
 269         pmbe->vpn       = vpn;
 270         pmbe->ppn       = ppn;
 271         pmbe->flags     = flags;
 272         pmbe->entry     = pos;
 273
 274         return pmbe;
 275
 276 out:
 277         write_unlock_irqrestore(&pmb_rwlock, irqflags);
 278         return ret;
 279 }
 280
 281 static void pmb_free(struct pmb_entry *pmbe)
 282 {
 283         __clear_bit(pmbe->entry, pmb_map);
 284
 285         pmbe->entry     = PMB_NO_ENTRY;
 286         pmbe->link      = NULL;
 287 }
 288
 289 /*
 290  * Must be run uncached.
 291  */
 292 static void __set_pmb_entry(struct pmb_entry *pmbe)
 293 {
 294         unsigned long addr, data;
 295
 296         addr = mk_pmb_addr(pmbe->entry);
 297         data = mk_pmb_data(pmbe->entry);
 298
 299         jump_to_uncached();
 300
 301         /* Set V-bit */
 302         __raw_writel(pmbe->vpn | PMB_V, addr);
 303         __raw_writel(pmbe->ppn | pmbe->flags | PMB_V, data);
 304
 305         back_to_cached();
 306 }
 307
 308 static void __clear_pmb_entry(struct pmb_entry *pmbe)
 309 {
 310         unsigned long addr, data;
 311         unsigned long addr_val, data_val;
 312
 313         addr = mk_pmb_addr(pmbe->entry);
 314         data = mk_pmb_data(pmbe->entry);
 315
 316         addr_val = __raw_readl(addr);
 317         data_val = __raw_readl(data);
 318
 319         /* Clear V-bit */
 320         writel_uncached(addr_val & ~PMB_V, addr);
 321         writel_uncached(data_val & ~PMB_V, data);
 322 }
 323
 324 #ifdef CONFIG_PM
 325 static void set_pmb_entry(struct pmb_entry *pmbe)
 326 {
 327         unsigned long flags;
 328
 329         raw_spin_lock_irqsave(&pmbe->lock, flags);
 330         __set_pmb_entry(pmbe);
 331         raw_spin_unlock_irqrestore(&pmbe->lock, flags);
 332 }
 333 #endif /* CONFIG_PM */
 334
 335 int pmb_bolt_mapping(unsigned long vaddr, phys_addr_t phys,
 336                      unsigned long size, pgprot_t prot)
 337 {
 338         struct pmb_entry *pmbp, *pmbe;
 339         unsigned long orig_addr, orig_size;
 340         unsigned long flags, pmb_flags;
 341         int i, mapped;
 342
 343         if (size < SZ_16M)
 344                 return -EINVAL;
 345         if (!pmb_addr_valid(vaddr, size))
 346                 return -EFAULT;
 347         if (pmb_mapping_exists(vaddr, phys, size))
 348                 return 0;
 349
 350         orig_addr = vaddr;
 351         orig_size = size;
 352
 353         flush_tlb_kernel_range(vaddr, vaddr + size);
 354
 355         pmb_flags = pgprot_to_pmb_flags(prot);
 356         pmbp = NULL;
 357
 358         do {
 359                 for (i = mapped = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
 360                         if (size < pmb_sizes[i].size)
 361                                 continue;
 362
 363                         pmbe = pmb_alloc(vaddr, phys, pmb_flags |
 364                                          pmb_sizes[i].flag, PMB_NO_ENTRY);
 365                         if (IS_ERR(pmbe)) {
 366                                 pmb_unmap_entry(pmbp, mapped);
 367                                 return PTR_ERR(pmbe);
 368                         }
 369
 370                         raw_spin_lock_irqsave(&pmbe->lock, flags);
 371
 372                         pmbe->size = pmb_sizes[i].size;
 373
 374                         __set_pmb_entry(pmbe);
 375
 376                         phys    += pmbe->size;
 377                         vaddr   += pmbe->size;
 378                         size    -= pmbe->size;
 379
 380                         /*
 381                          * Link adjacent entries that span multiple PMB
 382                          * entries for easier tear-down.
 383                          */
 384                         if (likely(pmbp)) {
 385                                 raw_spin_lock_nested(&pmbp->lock,
 386                                                      SINGLE_DEPTH_NESTING);
 387                                 pmbp->link = pmbe;
 388                                 raw_spin_unlock(&pmbp->lock);
 389                         }
 390
 391                         pmbp = pmbe;
 392
 393                         /*
 394                          * Instead of trying smaller sizes on every
 395                          * iteration (even if we succeed in allocating
 396                          * space), try using pmb_sizes[i].size again.
 397                          */
 398                         i--;
 399                         mapped++;
 400
 401                         raw_spin_unlock_irqrestore(&pmbe->lock, flags);
 402                 }
 403         } while (size >= SZ_16M);
 404
 405         flush_cache_vmap(orig_addr, orig_addr + orig_size);
 406
 407         return 0;
 408 }
 409
 410 void __iomem *pmb_remap_caller(phys_addr_t phys, unsigned long size,
 411                                pgprot_t prot, void *caller)
 412 {
 413         unsigned long vaddr;
 414         phys_addr_t offset, last_addr;
 415         phys_addr_t align_mask;
 416         unsigned long aligned;
 417         struct vm_struct *area;
 418         int i, ret;
 419
 420         if (!pmb_iomapping_enabled)
 421                 return NULL;
 422
 423         /*
 424          * Small mappings need to go through the TLB.
 425          */
 426         if (size < SZ_16M)
 427                 return ERR_PTR(-EINVAL);
 428         if (!pmb_prot_valid(prot))
 429                 return ERR_PTR(-EINVAL);
 430
 431         for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++)
 432                 if (size >= pmb_sizes[i].size)
 433                         break;
 434
 435         last_addr = phys + size;
 436         align_mask = ~(pmb_sizes[i].size - 1);
 437         offset = phys & ~align_mask;
 438         phys &= align_mask;
 439         aligned = ALIGN(last_addr, pmb_sizes[i].size) - phys;
 440
 441         /*
 442          * XXX: This should really start from uncached_end, but this
 443          * causes the MMU to reset, so for now we restrict it to the
 444          * 0xb000...0xc000 range.
 445          */
 446         area = __get_vm_area_caller(aligned, VM_IOREMAP, 0xb0000000,
 447                                     P3SEG, caller);
 448         if (!area)
 449                 return NULL;
 450
 451         area->phys_addr = phys;
 452         vaddr = (unsigned long)area->addr;
 453
 454         ret = pmb_bolt_mapping(vaddr, phys, size, prot);
 455         if (unlikely(ret != 0))
 456                 return ERR_PTR(ret);
 457
 458         return (void __iomem *)(offset + (char *)vaddr);
 459 }
 460
 461 int pmb_unmap(void __iomem *addr)
 462 {
 463         struct pmb_entry *pmbe = NULL;
 464         unsigned long vaddr = (unsigned long __force)addr;
 465         int i, found = 0;
 466
 467         read_lock(&pmb_rwlock);
 468
 469         for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 470                 if (test_bit(i, pmb_map)) {
 471                         pmbe = &pmb_entry_list[i];
 472                         if (pmbe->vpn == vaddr) {
 473                                 found = 1;
 474                                 break;
 475                         }
 476                 }
 477         }
 478
 479         read_unlock(&pmb_rwlock);
 480
 481         if (found) {
 482                 pmb_unmap_entry(pmbe, NR_PMB_ENTRIES);
 483                 return 0;
 484         }
 485
 486         return -EINVAL;
 487 }
 488
 489 static void __pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
 490 {
 491         do {
 492                 struct pmb_entry *pmblink = pmbe;
 493
 494                 /*
 495                  * We may be called before this pmb_entry has been
 496                  * entered into the PMB table via set_pmb_entry(), but
 497                  * that's OK because we've allocated a unique slot for
 498                  * this entry in pmb_alloc() (even if we haven't filled
 499                  * it yet).
 500                  *
 501                  * Therefore, calling __clear_pmb_entry() is safe as no
 502                  * other mapping can be using that slot.
 503                  */
 504                 __clear_pmb_entry(pmbe);
 505
 506                 flush_cache_vunmap(pmbe->vpn, pmbe->vpn + pmbe->size);
 507
 508                 pmbe = pmblink->link;
 509
 510                 pmb_free(pmblink);
 511         } while (pmbe && --depth);
 512 }
 513
 514 static void pmb_unmap_entry(struct pmb_entry *pmbe, int depth)
 515 {
 516         unsigned long flags;
 517
 518         if (unlikely(!pmbe))
 519                 return;
 520
 521         write_lock_irqsave(&pmb_rwlock, flags);
 522         __pmb_unmap_entry(pmbe, depth);
 523         write_unlock_irqrestore(&pmb_rwlock, flags);
 524 }
 525
 526 static void __init pmb_notify(void)
 527 {
 528         int i;
 529
 530         pr_info("PMB: boot mappings:\n");
 531
 532         read_lock(&pmb_rwlock);
 533
 534         for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 535                 struct pmb_entry *pmbe;
 536
 537                 if (!test_bit(i, pmb_map))
 538                         continue;
 539
 540                 pmbe = &pmb_entry_list[i];
 541
 542                 pr_info("       0x%08lx -> 0x%08lx [ %4ldMB %2scached ]\n",
 543                         pmbe->vpn >> PAGE_SHIFT, pmbe->ppn >> PAGE_SHIFT,
 544                         pmbe->size >> 20, (pmbe->flags & PMB_C) ? "" : "un");
 545         }
 546
 547         read_unlock(&pmb_rwlock);
 548 }
 549
 550 /*
 551  * Sync our software copy of the PMB mappings with those in hardware. The
 552  * mappings in the hardware PMB were either set up by the bootloader or
 553  * very early on by the kernel.
 554  */
 555 static void __init pmb_synchronize(void)
 556 {
 557         struct pmb_entry *pmbp = NULL;
 558         int i, j;
 559
 560         /*
 561          * Run through the initial boot mappings, log the established
 562          * ones, and blow away anything that falls outside of the valid
 563          * PPN range. Specifically, we only care about existing mappings
 564          * that impact the cached/uncached sections.
 565          *
 566          * Note that touching these can be a bit of a minefield; the boot
 567          * loader can establish multi-page mappings with the same caching
 568          * attributes, so we need to ensure that we aren't modifying a
 569          * mapping that we're presently executing from, or may execute
 570          * from in the case of straddling page boundaries.
 571          *
 572          * In the future we will have to tidy up after the boot loader by
 573          * jumping between the cached and uncached mappings and tearing
 574          * down alternating mappings while executing from the other.
 575          */
 576         for (i = 0; i < NR_PMB_ENTRIES; i++) {
 577                 unsigned long addr, data;
 578                 unsigned long addr_val, data_val;
 579                 unsigned long ppn, vpn, flags;
 580                 unsigned long irqflags;
 581                 unsigned int size;
 582                 struct pmb_entry *pmbe;
 583
 584                 addr = mk_pmb_addr(i);
 585                 data = mk_pmb_data(i);
 586
 587                 addr_val = __raw_readl(addr);
 588                 data_val = __raw_readl(data);
 589
 590                 /*
 591                  * Skip over any bogus entries
 592                  */
 593                 if (!(data_val & PMB_V) || !(addr_val & PMB_V))
 594                         continue;
 595
 596                 ppn = data_val & PMB_PFN_MASK;
 597                 vpn = addr_val & PMB_PFN_MASK;
 598
 599                 /*
 600                  * Only preserve in-range mappings.
 601                  */
 602                 if (!pmb_ppn_in_range(ppn)) {
 603                         /*
 604                          * Invalidate anything out of bounds.
 605                          */
 606                         writel_uncached(addr_val & ~PMB_V, addr);
 607                         writel_uncached(data_val & ~PMB_V, data);
 608                         continue;
 609                 }
 610
 611                 /*
 612                  * Update the caching attributes if necessary
 613                  */
 614                 if (data_val & PMB_C) {
 615                         data_val &= ~PMB_CACHE_MASK;
 616                         data_val |= pmb_cache_flags();
 617
 618                         writel_uncached(data_val, data);
 619                 }
 620
 621                 size = data_val & PMB_SZ_MASK;
 622                 flags = size | (data_val & PMB_CACHE_MASK);
 623
 624                 pmbe = pmb_alloc(vpn, ppn, flags, i);
 625                 if (IS_ERR(pmbe)) {
 626                         WARN_ON_ONCE(1);
 627                         continue;
 628                 }
 629
 630                 raw_spin_lock_irqsave(&pmbe->lock, irqflags);
 631
 632                 for (j = 0; j < ARRAY_SIZE(pmb_sizes); j++)
 633                         if (pmb_sizes[j].flag == size)
 634                                 pmbe->size = pmb_sizes[j].size;
 635
 636                 if (pmbp) {
 637                         raw_spin_lock_nested(&pmbp->lock, SINGLE_DEPTH_NESTING);
 638                         /*
 639                          * Compare the previous entry against the current one to
 640                          * see if the entries span a contiguous mapping. If so,
 641                          * setup the entry links accordingly. Compound mappings
 642                          * are later coalesced.
 643                          */
 644                         if (pmb_can_merge(pmbp, pmbe))
 645                                 pmbp->link = pmbe;
 646                         raw_spin_unlock(&pmbp->lock);
 647                 }
 648
 649                 pmbp = pmbe;
 650
 651                 raw_spin_unlock_irqrestore(&pmbe->lock, irqflags);
 652         }
 653 }
 654
 655 static void __init pmb_merge(struct pmb_entry *head)
 656 {
 657         unsigned long span, newsize;
 658         struct pmb_entry *tail;
 659         int i = 1, depth = 0;
 660
 661         span = newsize = head->size;
 662
 663         tail = head->link;
 664         while (tail) {
 665                 span += tail->size;
 666
 667                 if (pmb_size_valid(span)) {
 668                         newsize = span;
 669                         depth = i;
 670                 }
 671
 672                 /* This is the end of the line.. */
 673                 if (!tail->link)
 674                         break;
 675
 676                 tail = tail->link;
 677                 i++;
 678         }
 679
 680         /*
 681          * The merged page size must be valid.
 682          */
 683         if (!depth || !pmb_size_valid(newsize))
 684                 return;
 685
 686         head->flags &= ~PMB_SZ_MASK;
 687         head->flags |= pmb_size_to_flags(newsize);
 688
 689         head->size = newsize;
 690
 691         __pmb_unmap_entry(head->link, depth);
 692         __set_pmb_entry(head);
 693 }
 694
 695 static void __init pmb_coalesce(void)
 696 {
 697         unsigned long flags;
 698         int i;
 699
 700         write_lock_irqsave(&pmb_rwlock, flags);
 701
 702         for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 703                 struct pmb_entry *pmbe;
 704
 705                 if (!test_bit(i, pmb_map))
 706                         continue;
 707
 708                 pmbe = &pmb_entry_list[i];
 709
 710                 /*
 711                  * We're only interested in compound mappings
 712                  */
 713                 if (!pmbe->link)
 714                         continue;
 715
 716                 /*
 717                  * Nothing to do if it already uses the largest possible
 718                  * page size.
 719                  */
 720                 if (pmbe->size == SZ_512M)
 721                         continue;
 722
 723                 pmb_merge(pmbe);
 724         }
 725
 726         write_unlock_irqrestore(&pmb_rwlock, flags);
 727 }
 728
 729 #ifdef CONFIG_UNCACHED_MAPPING
 730 static void __init pmb_resize(void)
 731 {
 732         int i;
 733
 734         /*
 735          * If the uncached mapping was constructed by the kernel, it will
 736          * already be a reasonable size.
 737          */
 738         if (uncached_size == SZ_16M)
 739                 return;
 740
 741         read_lock(&pmb_rwlock);
 742
 743         for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 744                 struct pmb_entry *pmbe;
 745                 unsigned long flags;
 746
 747                 if (!test_bit(i, pmb_map))
 748                         continue;
 749
 750                 pmbe = &pmb_entry_list[i];
 751
 752                 if (pmbe->vpn != uncached_start)
 753                         continue;
 754
 755                 /*
 756                  * Found it, now resize it.
 757                  */
 758                 raw_spin_lock_irqsave(&pmbe->lock, flags);
 759
 760                 pmbe->size = SZ_16M;
 761                 pmbe->flags &= ~PMB_SZ_MASK;
 762                 pmbe->flags |= pmb_size_to_flags(pmbe->size);
 763
 764                 uncached_resize(pmbe->size);
 765
 766                 __set_pmb_entry(pmbe);
 767
 768                 raw_spin_unlock_irqrestore(&pmbe->lock, flags);
 769         }
 770
 771         read_unlock(&pmb_rwlock);
 772 }
 773 #endif
 774
 775 static int __init early_pmb(char *p)
 776 {
 777         if (!p)
 778                 return 0;
 779
 780         if (strstr(p, "iomap"))
 781                 pmb_iomapping_enabled = 1;
 782
 783         return 0;
 784 }
 785 early_param("pmb", early_pmb);
 786
 787 void __init pmb_init(void)
 788 {
 789         /* Synchronize software state */
 790         pmb_synchronize();
 791
 792         /* Attempt to combine compound mappings */
 793         pmb_coalesce();
 794
 795 #ifdef CONFIG_UNCACHED_MAPPING
 796         /* Resize initial mappings, if necessary */
 797         pmb_resize();
 798 #endif
 799
 800         /* Log them */
 801         pmb_notify();
 802
 803         writel_uncached(0, PMB_IRMCR);
 804
 805         /* Flush out the TLB */
 806         local_flush_tlb_all();
 807         ctrl_barrier();
 808 }
 809
 810 bool __in_29bit_mode(void)
 811 {
 812         return (__raw_readl(PMB_PASCR) & PASCR_SE) == 0;
 813 }
 814
 815 static int pmb_seq_show(struct seq_file *file, void *iter)
 816 {
 817         int i;
 818
 819         seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
 820                          "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
 821         seq_printf(file, "ety   vpn  ppn  size   flags\n");
 822
 823         for (i = 0; i < NR_PMB_ENTRIES; i++) {
 824                 unsigned long addr, data;
 825                 unsigned int size;
 826                 char *sz_str = NULL;
 827
 828                 addr = __raw_readl(mk_pmb_addr(i));
 829                 data = __raw_readl(mk_pmb_data(i));
 830
 831                 size = data & PMB_SZ_MASK;
 832                 sz_str = (size == PMB_SZ_16M)  ? " 16MB":
 833                          (size == PMB_SZ_64M)  ? " 64MB":
 834                          (size == PMB_SZ_128M) ? "128MB":
 835                                                  "512MB";
 836
 837                 /* 02: V 0x88 0x08 128MB C CB  B */
 838                 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
 839                            i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
 840                            (addr >> 24) & 0xff, (data >> 24) & 0xff,
 841                            sz_str, (data & PMB_C) ? 'C' : ' ',
 842                            (data & PMB_WT) ? "WT" : "CB",
 843                            (data & PMB_UB) ? "UB" : " B");
 844         }
 845
 846         return 0;
 847 }
 848
 849 static int pmb_debugfs_open(struct inode *inode, struct file *file)
 850 {
 851         return single_open(file, pmb_seq_show, NULL);
 852 }
 853
 854 static const struct file_operations pmb_debugfs_fops = {
 855         .owner          = THIS_MODULE,
 856         .open           = pmb_debugfs_open,
 857         .read           = seq_read,
 858         .llseek         = seq_lseek,
 859         .release        = single_release,
 860 };
 861
 862 static int __init pmb_debugfs_init(void)
 863 {
 864         struct dentry *dentry;
 865
 866         dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
 867                                      arch_debugfs_dir, NULL, &pmb_debugfs_fops);
 868         if (!dentry)
 869                 return -ENOMEM;
 870
 871         return 0;
 872 }
 873 subsys_initcall(pmb_debugfs_init);
 874
 875 #ifdef CONFIG_PM
 876 static void pmb_syscore_resume(void)
 877 {
 878         struct pmb_entry *pmbe;
 879         int i;
 880
 881         read_lock(&pmb_rwlock);
 882
 883         for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) {
 884                 if (test_bit(i, pmb_map)) {
 885                         pmbe = &pmb_entry_list[i];
 886                         set_pmb_entry(pmbe);
 887                 }
 888         }
 889
 890         read_unlock(&pmb_rwlock);
 891 }
 892
 893 static struct syscore_ops pmb_syscore_ops = {
 894         .resume = pmb_syscore_resume,
 895 };
 896
 897 static int __init pmb_sysdev_init(void)
 898 {
 899         register_syscore_ops(&pmb_syscore_ops);
 900         return 0;
 901 }
 902 subsys_initcall(pmb_sysdev_init);
 903 #endif