linux/arch/ia64/include/asm/pgtable.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_IA64_PGTABLE_H
   3#define _ASM_IA64_PGTABLE_H
   4
   5/*
   6 * This file contains the functions and defines necessary to modify and use
   7 * the IA-64 page table tree.
   8 *
   9 * This hopefully works with any (fixed) IA-64 page-size, as defined
  10 * in <asm/page.h>.
  11 *
  12 * Copyright (C) 1998-2005 Hewlett-Packard Co
  13 *      David Mosberger-Tang <davidm@hpl.hp.com>
  14 */
  15
  16
  17#include <asm/mman.h>
  18#include <asm/page.h>
  19#include <asm/processor.h>
  20#include <asm/types.h>
  21
  22#define IA64_MAX_PHYS_BITS      50      /* max. number of physical address bits (architected) */
  23
  24/*
  25 * First, define the various bits in a PTE.  Note that the PTE format
  26 * matches the VHPT short format, the firt doubleword of the VHPD long
  27 * format, and the first doubleword of the TLB insertion format.
  28 */
  29#define _PAGE_P_BIT             0
  30#define _PAGE_A_BIT             5
  31#define _PAGE_D_BIT             6
  32
  33#define _PAGE_P                 (1 << _PAGE_P_BIT)      /* page present bit */
  34#define _PAGE_MA_WB             (0x0 <<  2)     /* write back memory attribute */
  35#define _PAGE_MA_UC             (0x4 <<  2)     /* uncacheable memory attribute */
  36#define _PAGE_MA_UCE            (0x5 <<  2)     /* UC exported attribute */
  37#define _PAGE_MA_WC             (0x6 <<  2)     /* write coalescing memory attribute */
  38#define _PAGE_MA_NAT            (0x7 <<  2)     /* not-a-thing attribute */
  39#define _PAGE_MA_MASK           (0x7 <<  2)
  40#define _PAGE_PL_0              (0 <<  7)       /* privilege level 0 (kernel) */
  41#define _PAGE_PL_1              (1 <<  7)       /* privilege level 1 (unused) */
  42#define _PAGE_PL_2              (2 <<  7)       /* privilege level 2 (unused) */
  43#define _PAGE_PL_3              (3 <<  7)       /* privilege level 3 (user) */
  44#define _PAGE_PL_MASK           (3 <<  7)
  45#define _PAGE_AR_R              (0 <<  9)       /* read only */
  46#define _PAGE_AR_RX             (1 <<  9)       /* read & execute */
  47#define _PAGE_AR_RW             (2 <<  9)       /* read & write */
  48#define _PAGE_AR_RWX            (3 <<  9)       /* read, write & execute */
  49#define _PAGE_AR_R_RW           (4 <<  9)       /* read / read & write */
  50#define _PAGE_AR_RX_RWX         (5 <<  9)       /* read & exec / read, write & exec */
  51#define _PAGE_AR_RWX_RW         (6 <<  9)       /* read, write & exec / read & write */
  52#define _PAGE_AR_X_RX           (7 <<  9)       /* exec & promote / read & exec */
  53#define _PAGE_AR_MASK           (7 <<  9)
  54#define _PAGE_AR_SHIFT          9
  55#define _PAGE_A                 (1 << _PAGE_A_BIT)      /* page accessed bit */
  56#define _PAGE_D                 (1 << _PAGE_D_BIT)      /* page dirty bit */
  57#define _PAGE_PPN_MASK          (((__IA64_UL(1) << IA64_MAX_PHYS_BITS) - 1) & ~0xfffUL)
  58#define _PAGE_ED                (__IA64_UL(1) << 52)    /* exception deferral */
  59#define _PAGE_PROTNONE          (__IA64_UL(1) << 63)
  60
  61#define _PFN_MASK               _PAGE_PPN_MASK
  62/* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
  63#define _PAGE_CHG_MASK  (_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)
  64
  65#define _PAGE_SIZE_4K   12
  66#define _PAGE_SIZE_8K   13
  67#define _PAGE_SIZE_16K  14
  68#define _PAGE_SIZE_64K  16
  69#define _PAGE_SIZE_256K 18
  70#define _PAGE_SIZE_1M   20
  71#define _PAGE_SIZE_4M   22
  72#define _PAGE_SIZE_16M  24
  73#define _PAGE_SIZE_64M  26
  74#define _PAGE_SIZE_256M 28
  75#define _PAGE_SIZE_1G   30
  76#define _PAGE_SIZE_4G   32
  77
  78#define __ACCESS_BITS           _PAGE_ED | _PAGE_A | _PAGE_P | _PAGE_MA_WB
  79#define __DIRTY_BITS_NO_ED      _PAGE_A | _PAGE_P | _PAGE_D | _PAGE_MA_WB
  80#define __DIRTY_BITS            _PAGE_ED | __DIRTY_BITS_NO_ED
  81
  82/*
  83 * How many pointers will a page table level hold expressed in shift
  84 */
  85#define PTRS_PER_PTD_SHIFT      (PAGE_SHIFT-3)
  86
  87/*
  88 * Definitions for fourth level:
  89 */
  90#define PTRS_PER_PTE    (__IA64_UL(1) << (PTRS_PER_PTD_SHIFT))
  91
  92/*
  93 * Definitions for third level:
  94 *
  95 * PMD_SHIFT determines the size of the area a third-level page table
  96 * can map.
  97 */
  98#define PMD_SHIFT       (PAGE_SHIFT + (PTRS_PER_PTD_SHIFT))
  99#define PMD_SIZE        (1UL << PMD_SHIFT)
 100#define PMD_MASK        (~(PMD_SIZE-1))
 101#define PTRS_PER_PMD    (1UL << (PTRS_PER_PTD_SHIFT))
 102
 103#if CONFIG_PGTABLE_LEVELS == 4
 104/*
 105 * Definitions for second level:
 106 *
 107 * PUD_SHIFT determines the size of the area a second-level page table
 108 * can map.
 109 */
 110#define PUD_SHIFT       (PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
 111#define PUD_SIZE        (1UL << PUD_SHIFT)
 112#define PUD_MASK        (~(PUD_SIZE-1))
 113#define PTRS_PER_PUD    (1UL << (PTRS_PER_PTD_SHIFT))
 114#endif
 115
 116/*
 117 * Definitions for first level:
 118 *
 119 * PGDIR_SHIFT determines what a first-level page table entry can map.
 120 */
 121#if CONFIG_PGTABLE_LEVELS == 4
 122#define PGDIR_SHIFT             (PUD_SHIFT + (PTRS_PER_PTD_SHIFT))
 123#else
 124#define PGDIR_SHIFT             (PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
 125#endif
 126#define PGDIR_SIZE              (__IA64_UL(1) << PGDIR_SHIFT)
 127#define PGDIR_MASK              (~(PGDIR_SIZE-1))
 128#define PTRS_PER_PGD_SHIFT      PTRS_PER_PTD_SHIFT
 129#define PTRS_PER_PGD            (1UL << PTRS_PER_PGD_SHIFT)
 130#define USER_PTRS_PER_PGD       (5*PTRS_PER_PGD/8)      /* regions 0-4 are user regions */
 131
 132/*
 133 * All the normal masks have the "page accessed" bits on, as any time
 134 * they are used, the page is accessed. They are cleared only by the
 135 * page-out routines.
 136 */
 137#define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_A)
 138#define PAGE_SHARED     __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
 139#define PAGE_READONLY   __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
 140#define PAGE_COPY       __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
 141#define PAGE_COPY_EXEC  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
 142#define PAGE_GATE       __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
 143#define PAGE_KERNEL     __pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
 144#define PAGE_KERNELRX   __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
 145#define PAGE_KERNEL_UC  __pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX | \
 146                                 _PAGE_MA_UC)
 147
 148# ifndef __ASSEMBLY__
 149
 150#include <linux/sched/mm.h>     /* for mm_struct */
 151#include <linux/bitops.h>
 152#include <asm/cacheflush.h>
 153#include <asm/mmu_context.h>
 154
 155/*
 156 * Next come the mappings that determine how mmap() protection bits
 157 * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
 158 * _P version gets used for a private shared memory segment, the _S
 159 * version gets used for a shared memory segment with MAP_SHARED on.
 160 * In a private shared memory segment, we do a copy-on-write if a task
 161 * attempts to write to the page.
 162 */
 163        /* xwr */
 164#define __P000  PAGE_NONE
 165#define __P001  PAGE_READONLY
 166#define __P010  PAGE_READONLY   /* write to priv pg -> copy & make writable */
 167#define __P011  PAGE_READONLY   /* ditto */
 168#define __P100  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
 169#define __P101  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
 170#define __P110  PAGE_COPY_EXEC
 171#define __P111  PAGE_COPY_EXEC
 172
 173#define __S000  PAGE_NONE
 174#define __S001  PAGE_READONLY
 175#define __S010  PAGE_SHARED     /* we don't have (and don't need) write-only */
 176#define __S011  PAGE_SHARED
 177#define __S100  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_X_RX)
 178#define __S101  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
 179#define __S110  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
 180#define __S111  __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RWX)
 181
 182#define pgd_ERROR(e)    printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
 183#if CONFIG_PGTABLE_LEVELS == 4
 184#define pud_ERROR(e)    printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
 185#endif
 186#define pmd_ERROR(e)    printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
 187#define pte_ERROR(e)    printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
 188
 189
 190/*
 191 * Some definitions to translate between mem_map, PTEs, and page addresses:
 192 */
 193
 194
 195/* Quick test to see if ADDR is a (potentially) valid physical address. */
 196static inline long
 197ia64_phys_addr_valid (unsigned long addr)
 198{
 199        return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
 200}
 201
 202/*
 203 * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
 204 * memory.  For the return value to be meaningful, ADDR must be >=
 205 * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
 206 * require a hash-, or multi-level tree-lookup or something of that
 207 * sort) but it guarantees to return TRUE only if accessing the page
 208 * at that address does not cause an error.  Note that there may be
 209 * addresses for which kern_addr_valid() returns FALSE even though an
 210 * access would not cause an error (e.g., this is typically true for
 211 * memory mapped I/O regions.
 212 *
 213 * XXX Need to implement this for IA-64.
 214 */
 215#define kern_addr_valid(addr)   (1)
 216
 217
 218/*
 219 * Now come the defines and routines to manage and access the three-level
 220 * page table.
 221 */
 222
 223
 224#define VMALLOC_START           (RGN_BASE(RGN_GATE) + 0x200000000UL)
 225#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
 226/* SPARSEMEM_VMEMMAP uses half of vmalloc... */
 227# define VMALLOC_END            (RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
 228# define vmemmap                ((struct page *)VMALLOC_END)
 229#else
 230# define VMALLOC_END            (RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
 231#endif
 232
 233/* fs/proc/kcore.c */
 234#define kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
 235#define kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
 236
 237#define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
 238#define RGN_MAP_LIMIT   ((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)    /* per region addr limit */
 239
 240/*
 241 * Conversion functions: convert page frame number (pfn) and a protection value to a page
 242 * table entry (pte).
 243 */
 244#define pfn_pte(pfn, pgprot) \
 245({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
 246
 247/* Extract pfn from pte.  */
 248#define pte_pfn(_pte)           ((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
 249
 250#define mk_pte(page, pgprot)    pfn_pte(page_to_pfn(page), (pgprot))
 251
 252/* This takes a physical page address that is used by the remapping functions */
 253#define mk_pte_phys(physpage, pgprot) \
 254({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
 255
 256#define pte_modify(_pte, newprot) \
 257        (__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
 258
 259#define pte_none(pte)                   (!pte_val(pte))
 260#define pte_present(pte)                (pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
 261#define pte_clear(mm,addr,pte)          (pte_val(*(pte)) = 0UL)
 262/* pte_page() returns the "struct page *" corresponding to the PTE: */
 263#define pte_page(pte)                   virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
 264
 265#define pmd_none(pmd)                   (!pmd_val(pmd))
 266#define pmd_bad(pmd)                    (!ia64_phys_addr_valid(pmd_val(pmd)))
 267#define pmd_present(pmd)                (pmd_val(pmd) != 0UL)
 268#define pmd_clear(pmdp)                 (pmd_val(*(pmdp)) = 0UL)
 269#define pmd_page_vaddr(pmd)             ((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
 270#define pmd_page(pmd)                   virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
 271
 272#define pud_none(pud)                   (!pud_val(pud))
 273#define pud_bad(pud)                    (!ia64_phys_addr_valid(pud_val(pud)))
 274#define pud_present(pud)                (pud_val(pud) != 0UL)
 275#define pud_clear(pudp)                 (pud_val(*(pudp)) = 0UL)
 276#define pud_pgtable(pud)                ((pmd_t *) __va(pud_val(pud) & _PFN_MASK))
 277#define pud_page(pud)                   virt_to_page((pud_val(pud) + PAGE_OFFSET))
 278
 279#if CONFIG_PGTABLE_LEVELS == 4
 280#define p4d_none(p4d)                   (!p4d_val(p4d))
 281#define p4d_bad(p4d)                    (!ia64_phys_addr_valid(p4d_val(p4d)))
 282#define p4d_present(p4d)                (p4d_val(p4d) != 0UL)
 283#define p4d_clear(p4dp)                 (p4d_val(*(p4dp)) = 0UL)
 284#define p4d_pgtable(p4d)                ((pud_t *) __va(p4d_val(p4d) & _PFN_MASK))
 285#define p4d_page(p4d)                   virt_to_page((p4d_val(p4d) + PAGE_OFFSET))
 286#endif
 287
 288/*
 289 * The following have defined behavior only work if pte_present() is true.
 290 */
 291#define pte_write(pte)  ((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
 292#define pte_exec(pte)           ((pte_val(pte) & _PAGE_AR_RX) != 0)
 293#define pte_dirty(pte)          ((pte_val(pte) & _PAGE_D) != 0)
 294#define pte_young(pte)          ((pte_val(pte) & _PAGE_A) != 0)
 295
 296/*
 297 * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
 298 * access rights:
 299 */
 300#define pte_wrprotect(pte)      (__pte(pte_val(pte) & ~_PAGE_AR_RW))
 301#define pte_mkwrite(pte)        (__pte(pte_val(pte) | _PAGE_AR_RW))
 302#define pte_mkold(pte)          (__pte(pte_val(pte) & ~_PAGE_A))
 303#define pte_mkyoung(pte)        (__pte(pte_val(pte) | _PAGE_A))
 304#define pte_mkclean(pte)        (__pte(pte_val(pte) & ~_PAGE_D))
 305#define pte_mkdirty(pte)        (__pte(pte_val(pte) | _PAGE_D))
 306#define pte_mkhuge(pte)         (__pte(pte_val(pte)))
 307
 308/*
 309 * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
 310 * sync icache and dcache when we insert *new* executable page.
 311 *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
 312 * if necessary.
 313 *
 314 *  set_pte() is also called by the kernel, but we can expect that the kernel
 315 *  flushes icache explicitly if necessary.
 316 */
 317#define pte_present_exec_user(pte)\
 318        ((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
 319                (_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
 320
 321extern void __ia64_sync_icache_dcache(pte_t pteval);
 322static inline void set_pte(pte_t *ptep, pte_t pteval)
 323{
 324        /* page is present && page is user  && page is executable
 325         * && (page swapin or new page or page migration
 326         *      || copy_on_write with page copying.)
 327         */
 328        if (pte_present_exec_user(pteval) &&
 329            (!pte_present(*ptep) ||
 330                pte_pfn(*ptep) != pte_pfn(pteval)))
 331                /* load_module() calles flush_icache_range() explicitly*/
 332                __ia64_sync_icache_dcache(pteval);
 333        *ptep = pteval;
 334}
 335
 336#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 337
 338/*
 339 * Make page protection values cacheable, uncacheable, or write-
 340 * combining.  Note that "protection" is really a misnomer here as the
 341 * protection value contains the memory attribute bits, dirty bits, and
 342 * various other bits as well.
 343 */
 344#define pgprot_cacheable(prot)          __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
 345#define pgprot_noncached(prot)          __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
 346#define pgprot_writecombine(prot)       __pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
 347
 348struct file;
 349extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 350                                     unsigned long size, pgprot_t vma_prot);
 351#define __HAVE_PHYS_MEM_ACCESS_PROT
 352
 353static inline unsigned long
 354pgd_index (unsigned long address)
 355{
 356        unsigned long region = address >> 61;
 357        unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
 358
 359        return (region << (PAGE_SHIFT - 6)) | l1index;
 360}
 361#define pgd_index pgd_index
 362
 363/*
 364 * In the kernel's mapped region we know everything is in region number 5, so
 365 * as an optimisation its PGD already points to the area for that region.
 366 * However, this also means that we cannot use pgd_index() and we must
 367 * never add the region here.
 368 */
 369#define pgd_offset_k(addr) \
 370        (init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
 371
 372/* Look up a pgd entry in the gate area.  On IA-64, the gate-area
 373   resides in the kernel-mapped segment, hence we use pgd_offset_k()
 374   here.  */
 375#define pgd_offset_gate(mm, addr)       pgd_offset_k(addr)
 376
 377/* atomic versions of the some PTE manipulations: */
 378
 379static inline int
 380ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 381{
 382#ifdef CONFIG_SMP
 383        if (!pte_young(*ptep))
 384                return 0;
 385        return test_and_clear_bit(_PAGE_A_BIT, ptep);
 386#else
 387        pte_t pte = *ptep;
 388        if (!pte_young(pte))
 389                return 0;
 390        set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
 391        return 1;
 392#endif
 393}
 394
 395static inline pte_t
 396ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 397{
 398#ifdef CONFIG_SMP
 399        return __pte(xchg((long *) ptep, 0));
 400#else
 401        pte_t pte = *ptep;
 402        pte_clear(mm, addr, ptep);
 403        return pte;
 404#endif
 405}
 406
 407static inline void
 408ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 409{
 410#ifdef CONFIG_SMP
 411        unsigned long new, old;
 412
 413        do {
 414                old = pte_val(*ptep);
 415                new = pte_val(pte_wrprotect(__pte (old)));
 416        } while (cmpxchg((unsigned long *) ptep, old, new) != old);
 417#else
 418        pte_t old_pte = *ptep;
 419        set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
 420#endif
 421}
 422
 423static inline int
 424pte_same (pte_t a, pte_t b)
 425{
 426        return pte_val(a) == pte_val(b);
 427}
 428
 429#define update_mmu_cache(vma, address, ptep) do { } while (0)
 430
 431extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 432extern void paging_init (void);
 433
 434/*
 435 * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
 436 *       bits in the swap-type field of the swap pte.  It would be nice to
 437 *       enforce that, but we can't easily include <linux/swap.h> here.
 438 *       (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
 439 *
 440 * Format of swap pte:
 441 *      bit   0   : present bit (must be zero)
 442 *      bits  1- 7: swap-type
 443 *      bits  8-62: swap offset
 444 *      bit  63   : _PAGE_PROTNONE bit
 445 */
 446#define __swp_type(entry)               (((entry).val >> 1) & 0x7f)
 447#define __swp_offset(entry)             (((entry).val << 1) >> 9)
 448#define __swp_entry(type,offset)        ((swp_entry_t) { ((type) << 1) | ((long) (offset) << 8) })
 449#define __pte_to_swp_entry(pte)         ((swp_entry_t) { pte_val(pte) })
 450#define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 451
 452/*
 453 * ZERO_PAGE is a global shared page that is always zero: used
 454 * for zero-mapped memory areas etc..
 455 */
 456extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
 457extern struct page *zero_page_memmap_ptr;
 458#define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
 459
 460/* We provide our own get_unmapped_area to cope with VA holes for userland */
 461#define HAVE_ARCH_UNMAPPED_AREA
 462
 463#ifdef CONFIG_HUGETLB_PAGE
 464#define HUGETLB_PGDIR_SHIFT     (HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
 465#define HUGETLB_PGDIR_SIZE      (__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
 466#define HUGETLB_PGDIR_MASK      (~(HUGETLB_PGDIR_SIZE-1))
 467#endif
 468
 469
 470#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 471/*
 472 * Update PTEP with ENTRY, which is guaranteed to be a less
 473 * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
 474 * WRITABLE bits turned on, when the value at PTEP did not.  The
 475 * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
 476 *
 477 * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
 478 * having to worry about races.  On SMP machines, there are only two
 479 * cases where this is true:
 480 *
 481 *      (1) *PTEP has the PRESENT bit turned OFF
 482 *      (2) ENTRY has the DIRTY bit turned ON
 483 *
 484 * On ia64, we could implement this routine with a cmpxchg()-loop
 485 * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
 486 * However, like on x86, we can get a more streamlined version by
 487 * observing that it is OK to drop ACCESSED bit updates when
 488 * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
 489 * result in an extra Access-bit fault, which would then turn on the
 490 * ACCESSED bit in the low-level fault handler (iaccess_bit or
 491 * daccess_bit in ivt.S).
 492 */
 493#ifdef CONFIG_SMP
 494# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
 495({                                                                      \
 496        int __changed = !pte_same(*(__ptep), __entry);                  \
 497        if (__changed && __safely_writable) {                           \
 498                set_pte(__ptep, __entry);                               \
 499                flush_tlb_page(__vma, __addr);                          \
 500        }                                                               \
 501        __changed;                                                      \
 502})
 503#else
 504# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
 505({                                                                      \
 506        int __changed = !pte_same(*(__ptep), __entry);                  \
 507        if (__changed) {                                                \
 508                set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);  \
 509                flush_tlb_page(__vma, __addr);                          \
 510        }                                                               \
 511        __changed;                                                      \
 512})
 513#endif
 514# endif /* !__ASSEMBLY__ */
 515
 516/*
 517 * Identity-mapped regions use a large page size.  We'll call such large pages
 518 * "granules".  If you can think of a better name that's unambiguous, let me
 519 * know...
 520 */
 521#if defined(CONFIG_IA64_GRANULE_64MB)
 522# define IA64_GRANULE_SHIFT     _PAGE_SIZE_64M
 523#elif defined(CONFIG_IA64_GRANULE_16MB)
 524# define IA64_GRANULE_SHIFT     _PAGE_SIZE_16M
 525#endif
 526#define IA64_GRANULE_SIZE       (1 << IA64_GRANULE_SHIFT)
 527/*
 528 * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
 529 */
 530#define KERNEL_TR_PAGE_SHIFT    _PAGE_SIZE_64M
 531#define KERNEL_TR_PAGE_SIZE     (1 << KERNEL_TR_PAGE_SHIFT)
 532
 533/* These tell get_user_pages() that the first gate page is accessible from user-level.  */
 534#define FIXADDR_USER_START      GATE_ADDR
 535#ifdef HAVE_BUGGY_SEGREL
 536# define FIXADDR_USER_END       (GATE_ADDR + 2*PAGE_SIZE)
 537#else
 538# define FIXADDR_USER_END       (GATE_ADDR + 2*PERCPU_PAGE_SIZE)
 539#endif
 540
 541#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 542#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 543#define __HAVE_ARCH_PTEP_SET_WRPROTECT
 544#define __HAVE_ARCH_PTE_SAME
 545#define __HAVE_ARCH_PGD_OFFSET_GATE
 546
 547
 548#if CONFIG_PGTABLE_LEVELS == 3
 549#include <asm-generic/pgtable-nopud.h>
 550#endif
 551#include <asm-generic/pgtable-nop4d.h>
 552
 553#endif /* _ASM_IA64_PGTABLE_H */
 554