linux/arch/powerpc/include/asm/book3s/32/pgtable.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H
   3#define _ASM_POWERPC_BOOK3S_32_PGTABLE_H
   4
   5#define __ARCH_USE_5LEVEL_HACK
   6#include <asm-generic/pgtable-nopmd.h>
   7
   8#include <asm/book3s/32/hash.h>
   9
  10/* And here we include common definitions */
  11
  12#define _PAGE_KERNEL_RO         0
  13#define _PAGE_KERNEL_ROX        (_PAGE_EXEC)
  14#define _PAGE_KERNEL_RW         (_PAGE_DIRTY | _PAGE_RW)
  15#define _PAGE_KERNEL_RWX        (_PAGE_DIRTY | _PAGE_RW | _PAGE_EXEC)
  16
  17#define _PAGE_HPTEFLAGS _PAGE_HASHPTE
  18
  19#ifndef __ASSEMBLY__
  20
  21static inline bool pte_user(pte_t pte)
  22{
  23        return pte_val(pte) & _PAGE_USER;
  24}
  25#endif /* __ASSEMBLY__ */
  26
  27/*
  28 * Location of the PFN in the PTE. Most 32-bit platforms use the same
  29 * as _PAGE_SHIFT here (ie, naturally aligned).
  30 * Platform who don't just pre-define the value so we don't override it here.
  31 */
  32#define PTE_RPN_SHIFT   (PAGE_SHIFT)
  33
  34/*
  35 * The mask covered by the RPN must be a ULL on 32-bit platforms with
  36 * 64-bit PTEs.
  37 */
  38#ifdef CONFIG_PTE_64BIT
  39#define PTE_RPN_MASK    (~((1ULL << PTE_RPN_SHIFT) - 1))
  40#else
  41#define PTE_RPN_MASK    (~((1UL << PTE_RPN_SHIFT) - 1))
  42#endif
  43
  44/*
  45 * _PAGE_CHG_MASK masks of bits that are to be preserved across
  46 * pgprot changes.
  47 */
  48#define _PAGE_CHG_MASK  (PTE_RPN_MASK | _PAGE_HASHPTE | _PAGE_DIRTY | \
  49                         _PAGE_ACCESSED | _PAGE_SPECIAL)
  50
  51/*
  52 * We define 2 sets of base prot bits, one for basic pages (ie,
  53 * cacheable kernel and user pages) and one for non cacheable
  54 * pages. We always set _PAGE_COHERENT when SMP is enabled or
  55 * the processor might need it for DMA coherency.
  56 */
  57#define _PAGE_BASE_NC   (_PAGE_PRESENT | _PAGE_ACCESSED)
  58#define _PAGE_BASE      (_PAGE_BASE_NC | _PAGE_COHERENT)
  59
  60/*
  61 * Permission masks used to generate the __P and __S table.
  62 *
  63 * Note:__pgprot is defined in arch/powerpc/include/asm/page.h
  64 *
  65 * Write permissions imply read permissions for now.
  66 */
  67#define PAGE_NONE       __pgprot(_PAGE_BASE)
  68#define PAGE_SHARED     __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW)
  69#define PAGE_SHARED_X   __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC)
  70#define PAGE_COPY       __pgprot(_PAGE_BASE | _PAGE_USER)
  71#define PAGE_COPY_X     __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
  72#define PAGE_READONLY   __pgprot(_PAGE_BASE | _PAGE_USER)
  73#define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC)
  74
  75/* Permission masks used for kernel mappings */
  76#define PAGE_KERNEL     __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
  77#define PAGE_KERNEL_NC  __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)
  78#define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | \
  79                                 _PAGE_NO_CACHE | _PAGE_GUARDED)
  80#define PAGE_KERNEL_X   __pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
  81#define PAGE_KERNEL_RO  __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
  82#define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
  83
  84/*
  85 * Protection used for kernel text. We want the debuggers to be able to
  86 * set breakpoints anywhere, so don't write protect the kernel text
  87 * on platforms where such control is possible.
  88 */
  89#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
  90        defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
  91#define PAGE_KERNEL_TEXT        PAGE_KERNEL_X
  92#else
  93#define PAGE_KERNEL_TEXT        PAGE_KERNEL_ROX
  94#endif
  95
  96/* Make modules code happy. We don't set RO yet */
  97#define PAGE_KERNEL_EXEC        PAGE_KERNEL_X
  98
  99/* Advertise special mapping type for AGP */
 100#define PAGE_AGP                (PAGE_KERNEL_NC)
 101#define HAVE_PAGE_AGP
 102
 103#define PTE_INDEX_SIZE  PTE_SHIFT
 104#define PMD_INDEX_SIZE  0
 105#define PUD_INDEX_SIZE  0
 106#define PGD_INDEX_SIZE  (32 - PGDIR_SHIFT)
 107
 108#define PMD_CACHE_INDEX PMD_INDEX_SIZE
 109#define PUD_CACHE_INDEX PUD_INDEX_SIZE
 110
 111#ifndef __ASSEMBLY__
 112#define PTE_TABLE_SIZE  (sizeof(pte_t) << PTE_INDEX_SIZE)
 113#define PMD_TABLE_SIZE  0
 114#define PUD_TABLE_SIZE  0
 115#define PGD_TABLE_SIZE  (sizeof(pgd_t) << PGD_INDEX_SIZE)
 116#endif  /* __ASSEMBLY__ */
 117
 118#define PTRS_PER_PTE    (1 << PTE_INDEX_SIZE)
 119#define PTRS_PER_PGD    (1 << PGD_INDEX_SIZE)
 120
 121/*
 122 * The normal case is that PTEs are 32-bits and we have a 1-page
 123 * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
 124 *
 125 * For any >32-bit physical address platform, we can use the following
 126 * two level page table layout where the pgdir is 8KB and the MS 13 bits
 127 * are an index to the second level table.  The combined pgdir/pmd first
 128 * level has 2048 entries and the second level has 512 64-bit PTE entries.
 129 * -Matt
 130 */
 131/* PGDIR_SHIFT determines what a top-level page table entry can map */
 132#define PGDIR_SHIFT     (PAGE_SHIFT + PTE_INDEX_SIZE)
 133#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
 134#define PGDIR_MASK      (~(PGDIR_SIZE-1))
 135
 136#define USER_PTRS_PER_PGD       (TASK_SIZE / PGDIR_SIZE)
 137/*
 138 * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
 139 * value (for now) on others, from where we can start layout kernel
 140 * virtual space that goes below PKMAP and FIXMAP
 141 */
 142#ifdef CONFIG_HIGHMEM
 143#define KVIRT_TOP       PKMAP_BASE
 144#else
 145#define KVIRT_TOP       (0xfe000000UL)  /* for now, could be FIXMAP_BASE ? */
 146#endif
 147
 148/*
 149 * ioremap_bot starts at that address. Early ioremaps move down from there,
 150 * until mem_init() at which point this becomes the top of the vmalloc
 151 * and ioremap space
 152 */
 153#ifdef CONFIG_NOT_COHERENT_CACHE
 154#define IOREMAP_TOP     ((KVIRT_TOP - CONFIG_CONSISTENT_SIZE) & PAGE_MASK)
 155#else
 156#define IOREMAP_TOP     KVIRT_TOP
 157#endif
 158
 159/*
 160 * Just any arbitrary offset to the start of the vmalloc VM area: the
 161 * current 16MB value just means that there will be a 64MB "hole" after the
 162 * physical memory until the kernel virtual memory starts.  That means that
 163 * any out-of-bounds memory accesses will hopefully be caught.
 164 * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 165 * area for the same reason. ;)
 166 *
 167 * We no longer map larger than phys RAM with the BATs so we don't have
 168 * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
 169 * about clashes between our early calls to ioremap() that start growing down
 170 * from ioremap_base being run into the VM area allocations (growing upwards
 171 * from VMALLOC_START).  For this reason we have ioremap_bot to check when
 172 * we actually run into our mappings setup in the early boot with the VM
 173 * system.  This really does become a problem for machines with good amounts
 174 * of RAM.  -- Cort
 175 */
 176#define VMALLOC_OFFSET (0x1000000) /* 16M */
 177
 178/*
 179 * With CONFIG_STRICT_KERNEL_RWX, kernel segments are set NX. But when modules
 180 * are used, NX cannot be set on VMALLOC space. So vmalloc VM space and linear
 181 * memory shall not share segments.
 182 */
 183#if defined(CONFIG_STRICT_KERNEL_RWX) && defined(CONFIG_MODULES)
 184#define VMALLOC_START ((_ALIGN((long)high_memory, 256L << 20) + VMALLOC_OFFSET) & \
 185                       ~(VMALLOC_OFFSET - 1))
 186#else
 187#define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
 188#endif
 189#define VMALLOC_END     ioremap_bot
 190
 191#ifndef __ASSEMBLY__
 192#include <linux/sched.h>
 193#include <linux/threads.h>
 194
 195extern unsigned long ioremap_bot;
 196
 197/* Bits to mask out from a PGD to get to the PUD page */
 198#define PGD_MASKED_BITS         0
 199
 200#define pte_ERROR(e) \
 201        pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
 202                (unsigned long long)pte_val(e))
 203#define pgd_ERROR(e) \
 204        pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
 205/*
 206 * Bits in a linux-style PTE.  These match the bits in the
 207 * (hardware-defined) PowerPC PTE as closely as possible.
 208 */
 209
 210#define pte_clear(mm, addr, ptep) \
 211        do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
 212
 213#define pmd_none(pmd)           (!pmd_val(pmd))
 214#define pmd_bad(pmd)            (pmd_val(pmd) & _PMD_BAD)
 215#define pmd_present(pmd)        (pmd_val(pmd) & _PMD_PRESENT_MASK)
 216static inline void pmd_clear(pmd_t *pmdp)
 217{
 218        *pmdp = __pmd(0);
 219}
 220
 221
 222/*
 223 * When flushing the tlb entry for a page, we also need to flush the hash
 224 * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
 225 */
 226extern int flush_hash_pages(unsigned context, unsigned long va,
 227                            unsigned long pmdval, int count);
 228
 229/* Add an HPTE to the hash table */
 230extern void add_hash_page(unsigned context, unsigned long va,
 231                          unsigned long pmdval);
 232
 233/* Flush an entry from the TLB/hash table */
 234extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep,
 235                             unsigned long address);
 236
 237/*
 238 * PTE updates. This function is called whenever an existing
 239 * valid PTE is updated. This does -not- include set_pte_at()
 240 * which nowadays only sets a new PTE.
 241 *
 242 * Depending on the type of MMU, we may need to use atomic updates
 243 * and the PTE may be either 32 or 64 bit wide. In the later case,
 244 * when using atomic updates, only the low part of the PTE is
 245 * accessed atomically.
 246 *
 247 * In addition, on 44x, we also maintain a global flag indicating
 248 * that an executable user mapping was modified, which is needed
 249 * to properly flush the virtually tagged instruction cache of
 250 * those implementations.
 251 */
 252#ifndef CONFIG_PTE_64BIT
 253static inline unsigned long pte_update(pte_t *p,
 254                                       unsigned long clr,
 255                                       unsigned long set)
 256{
 257        unsigned long old, tmp;
 258
 259        __asm__ __volatile__("\
 2601:      lwarx   %0,0,%3\n\
 261        andc    %1,%0,%4\n\
 262        or      %1,%1,%5\n"
 263"       stwcx.  %1,0,%3\n\
 264        bne-    1b"
 265        : "=&r" (old), "=&r" (tmp), "=m" (*p)
 266        : "r" (p), "r" (clr), "r" (set), "m" (*p)
 267        : "cc" );
 268
 269        return old;
 270}
 271#else /* CONFIG_PTE_64BIT */
 272static inline unsigned long long pte_update(pte_t *p,
 273                                            unsigned long clr,
 274                                            unsigned long set)
 275{
 276        unsigned long long old;
 277        unsigned long tmp;
 278
 279        __asm__ __volatile__("\
 2801:      lwarx   %L0,0,%4\n\
 281        lwzx    %0,0,%3\n\
 282        andc    %1,%L0,%5\n\
 283        or      %1,%1,%6\n"
 284"       stwcx.  %1,0,%4\n\
 285        bne-    1b"
 286        : "=&r" (old), "=&r" (tmp), "=m" (*p)
 287        : "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
 288        : "cc" );
 289
 290        return old;
 291}
 292#endif /* CONFIG_PTE_64BIT */
 293
 294/*
 295 * 2.6 calls this without flushing the TLB entry; this is wrong
 296 * for our hash-based implementation, we fix that up here.
 297 */
 298#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 299static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
 300{
 301        unsigned long old;
 302        old = pte_update(ptep, _PAGE_ACCESSED, 0);
 303        if (old & _PAGE_HASHPTE) {
 304                unsigned long ptephys = __pa(ptep) & PAGE_MASK;
 305                flush_hash_pages(context, addr, ptephys, 1);
 306        }
 307        return (old & _PAGE_ACCESSED) != 0;
 308}
 309#define ptep_test_and_clear_young(__vma, __addr, __ptep) \
 310        __ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)
 311
 312#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 313static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 314                                       pte_t *ptep)
 315{
 316        return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
 317}
 318
 319#define __HAVE_ARCH_PTEP_SET_WRPROTECT
 320static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
 321                                      pte_t *ptep)
 322{
 323        pte_update(ptep, _PAGE_RW, 0);
 324}
 325
 326static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
 327                                           pte_t *ptep, pte_t entry,
 328                                           unsigned long address,
 329                                           int psize)
 330{
 331        unsigned long set = pte_val(entry) &
 332                (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
 333
 334        pte_update(ptep, 0, set);
 335
 336        flush_tlb_page(vma, address);
 337}
 338
 339#define __HAVE_ARCH_PTE_SAME
 340#define pte_same(A,B)   (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)
 341
 342#define pmd_page_vaddr(pmd)     \
 343        ((unsigned long)__va(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
 344#define pmd_page(pmd)           \
 345        pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
 346
 347/* to find an entry in a kernel page-table-directory */
 348#define pgd_offset_k(address) pgd_offset(&init_mm, address)
 349
 350/* to find an entry in a page-table-directory */
 351#define pgd_index(address)       ((address) >> PGDIR_SHIFT)
 352#define pgd_offset(mm, address)  ((mm)->pgd + pgd_index(address))
 353
 354/* Find an entry in the third-level page table.. */
 355#define pte_index(address)              \
 356        (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 357#define pte_offset_kernel(dir, addr)    \
 358        ((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
 359#define pte_offset_map(dir, addr)               \
 360        ((pte_t *)(kmap_atomic(pmd_page(*(dir))) + \
 361                   (pmd_page_vaddr(*(dir)) & ~PAGE_MASK)) + pte_index(addr))
 362#define pte_unmap(pte)          kunmap_atomic(pte)
 363
 364/*
 365 * Encode and decode a swap entry.
 366 * Note that the bits we use in a PTE for representing a swap entry
 367 * must not include the _PAGE_PRESENT bit or the _PAGE_HASHPTE bit (if used).
 368 *   -- paulus
 369 */
 370#define __swp_type(entry)               ((entry).val & 0x1f)
 371#define __swp_offset(entry)             ((entry).val >> 5)
 372#define __swp_entry(type, offset)       ((swp_entry_t) { (type) | ((offset) << 5) })
 373#define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val(pte) >> 3 })
 374#define __swp_entry_to_pte(x)           ((pte_t) { (x).val << 3 })
 375
 376int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
 377
 378/* Generic accessors to PTE bits */
 379static inline int pte_write(pte_t pte)          { return !!(pte_val(pte) & _PAGE_RW);}
 380static inline int pte_read(pte_t pte)           { return 1; }
 381static inline int pte_dirty(pte_t pte)          { return !!(pte_val(pte) & _PAGE_DIRTY); }
 382static inline int pte_young(pte_t pte)          { return !!(pte_val(pte) & _PAGE_ACCESSED); }
 383static inline int pte_special(pte_t pte)        { return !!(pte_val(pte) & _PAGE_SPECIAL); }
 384static inline int pte_none(pte_t pte)           { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
 385static inline bool pte_exec(pte_t pte)          { return pte_val(pte) & _PAGE_EXEC; }
 386
 387static inline int pte_present(pte_t pte)
 388{
 389        return pte_val(pte) & _PAGE_PRESENT;
 390}
 391
 392static inline bool pte_hw_valid(pte_t pte)
 393{
 394        return pte_val(pte) & _PAGE_PRESENT;
 395}
 396
 397static inline bool pte_hashpte(pte_t pte)
 398{
 399        return !!(pte_val(pte) & _PAGE_HASHPTE);
 400}
 401
 402static inline bool pte_ci(pte_t pte)
 403{
 404        return !!(pte_val(pte) & _PAGE_NO_CACHE);
 405}
 406
 407/*
 408 * We only find page table entry in the last level
 409 * Hence no need for other accessors
 410 */
 411#define pte_access_permitted pte_access_permitted
 412static inline bool pte_access_permitted(pte_t pte, bool write)
 413{
 414        /*
 415         * A read-only access is controlled by _PAGE_USER bit.
 416         * We have _PAGE_READ set for WRITE and EXECUTE
 417         */
 418        if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
 419                return false;
 420
 421        if (write && !pte_write(pte))
 422                return false;
 423
 424        return true;
 425}
 426
 427/* Conversion functions: convert a page and protection to a page entry,
 428 * and a page entry and page directory to the page they refer to.
 429 *
 430 * Even if PTEs can be unsigned long long, a PFN is always an unsigned
 431 * long for now.
 432 */
 433static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
 434{
 435        return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
 436                     pgprot_val(pgprot));
 437}
 438
 439static inline unsigned long pte_pfn(pte_t pte)
 440{
 441        return pte_val(pte) >> PTE_RPN_SHIFT;
 442}
 443
 444/* Generic modifiers for PTE bits */
 445static inline pte_t pte_wrprotect(pte_t pte)
 446{
 447        return __pte(pte_val(pte) & ~_PAGE_RW);
 448}
 449
 450static inline pte_t pte_exprotect(pte_t pte)
 451{
 452        return __pte(pte_val(pte) & ~_PAGE_EXEC);
 453}
 454
 455static inline pte_t pte_mkclean(pte_t pte)
 456{
 457        return __pte(pte_val(pte) & ~_PAGE_DIRTY);
 458}
 459
 460static inline pte_t pte_mkold(pte_t pte)
 461{
 462        return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
 463}
 464
 465static inline pte_t pte_mkexec(pte_t pte)
 466{
 467        return __pte(pte_val(pte) | _PAGE_EXEC);
 468}
 469
 470static inline pte_t pte_mkpte(pte_t pte)
 471{
 472        return pte;
 473}
 474
 475static inline pte_t pte_mkwrite(pte_t pte)
 476{
 477        return __pte(pte_val(pte) | _PAGE_RW);
 478}
 479
 480static inline pte_t pte_mkdirty(pte_t pte)
 481{
 482        return __pte(pte_val(pte) | _PAGE_DIRTY);
 483}
 484
 485static inline pte_t pte_mkyoung(pte_t pte)
 486{
 487        return __pte(pte_val(pte) | _PAGE_ACCESSED);
 488}
 489
 490static inline pte_t pte_mkspecial(pte_t pte)
 491{
 492        return __pte(pte_val(pte) | _PAGE_SPECIAL);
 493}
 494
 495static inline pte_t pte_mkhuge(pte_t pte)
 496{
 497        return pte;
 498}
 499
 500static inline pte_t pte_mkprivileged(pte_t pte)
 501{
 502        return __pte(pte_val(pte) & ~_PAGE_USER);
 503}
 504
 505static inline pte_t pte_mkuser(pte_t pte)
 506{
 507        return __pte(pte_val(pte) | _PAGE_USER);
 508}
 509
 510static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 511{
 512        return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
 513}
 514
 515
 516
 517/* This low level function performs the actual PTE insertion
 518 * Setting the PTE depends on the MMU type and other factors. It's
 519 * an horrible mess that I'm not going to try to clean up now but
 520 * I'm keeping it in one place rather than spread around
 521 */
 522static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 523                                pte_t *ptep, pte_t pte, int percpu)
 524{
 525#if defined(CONFIG_SMP) && !defined(CONFIG_PTE_64BIT)
 526        /* First case is 32-bit Hash MMU in SMP mode with 32-bit PTEs. We use the
 527         * helper pte_update() which does an atomic update. We need to do that
 528         * because a concurrent invalidation can clear _PAGE_HASHPTE. If it's a
 529         * per-CPU PTE such as a kmap_atomic, we do a simple update preserving
 530         * the hash bits instead (ie, same as the non-SMP case)
 531         */
 532        if (percpu)
 533                *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
 534                              | (pte_val(pte) & ~_PAGE_HASHPTE));
 535        else
 536                pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte));
 537
 538#elif defined(CONFIG_PTE_64BIT)
 539        /* Second case is 32-bit with 64-bit PTE.  In this case, we
 540         * can just store as long as we do the two halves in the right order
 541         * with a barrier in between. This is possible because we take care,
 542         * in the hash code, to pre-invalidate if the PTE was already hashed,
 543         * which synchronizes us with any concurrent invalidation.
 544         * In the percpu case, we also fallback to the simple update preserving
 545         * the hash bits
 546         */
 547        if (percpu) {
 548                *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
 549                              | (pte_val(pte) & ~_PAGE_HASHPTE));
 550                return;
 551        }
 552        if (pte_val(*ptep) & _PAGE_HASHPTE)
 553                flush_hash_entry(mm, ptep, addr);
 554        __asm__ __volatile__("\
 555                stw%U0%X0 %2,%0\n\
 556                eieio\n\
 557                stw%U0%X0 %L2,%1"
 558        : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
 559        : "r" (pte) : "memory");
 560
 561#else
 562        /* Third case is 32-bit hash table in UP mode, we need to preserve
 563         * the _PAGE_HASHPTE bit since we may not have invalidated the previous
 564         * translation in the hash yet (done in a subsequent flush_tlb_xxx())
 565         * and see we need to keep track that this PTE needs invalidating
 566         */
 567        *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
 568                      | (pte_val(pte) & ~_PAGE_HASHPTE));
 569#endif
 570}
 571
 572/*
 573 * Macro to mark a page protection value as "uncacheable".
 574 */
 575
 576#define _PAGE_CACHE_CTL (_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
 577                         _PAGE_WRITETHRU)
 578
 579#define pgprot_noncached pgprot_noncached
 580static inline pgprot_t pgprot_noncached(pgprot_t prot)
 581{
 582        return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
 583                        _PAGE_NO_CACHE | _PAGE_GUARDED);
 584}
 585
 586#define pgprot_noncached_wc pgprot_noncached_wc
 587static inline pgprot_t pgprot_noncached_wc(pgprot_t prot)
 588{
 589        return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
 590                        _PAGE_NO_CACHE);
 591}
 592
 593#define pgprot_cached pgprot_cached
 594static inline pgprot_t pgprot_cached(pgprot_t prot)
 595{
 596        return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
 597                        _PAGE_COHERENT);
 598}
 599
 600#define pgprot_cached_wthru pgprot_cached_wthru
 601static inline pgprot_t pgprot_cached_wthru(pgprot_t prot)
 602{
 603        return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
 604                        _PAGE_COHERENT | _PAGE_WRITETHRU);
 605}
 606
 607#define pgprot_cached_noncoherent pgprot_cached_noncoherent
 608static inline pgprot_t pgprot_cached_noncoherent(pgprot_t prot)
 609{
 610        return __pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL);
 611}
 612
 613#define pgprot_writecombine pgprot_writecombine
 614static inline pgprot_t pgprot_writecombine(pgprot_t prot)
 615{
 616        return pgprot_noncached_wc(prot);
 617}
 618
 619#endif /* !__ASSEMBLY__ */
 620
 621#endif /*  _ASM_POWERPC_BOOK3S_32_PGTABLE_H */
 622