Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 545 insertions, 0 deletions

diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
new file mode 100644
index 0000000000..9be2d2ba60
--- /dev/null
+++ b/arch/ia64/include/asm/pgtable.h
@@ -0,0 +1,545 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_IA64_PGTABLE_H
+#define _ASM_IA64_PGTABLE_H
+
+/*
+ * This file contains the functions and defines necessary to modify and use
+ * the IA-64 page table tree.
+ *
+ * This hopefully works with any (fixed) IA-64 page-size, as defined
+ * in <asm/page.h>.
+ *
+ * Copyright (C) 1998-2005 Hewlett-Packard Co
+ *	David Mosberger-Tang <davidm@hpl.hp.com>
+ */
+
+
+#include <asm/mman.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <asm/types.h>
+
+#define IA64_MAX_PHYS_BITS	50	/* max. number of physical address bits (architected) */
+
+/*
+ * First, define the various bits in a PTE.  Note that the PTE format
+ * matches the VHPT short format, the firt doubleword of the VHPD long
+ * format, and the first doubleword of the TLB insertion format.
+ */
+#define _PAGE_P_BIT		0
+#define _PAGE_A_BIT		5
+#define _PAGE_D_BIT		6
+
+#define _PAGE_P			(1 << _PAGE_P_BIT)	/* page present bit */
+#define _PAGE_MA_WB		(0x0 <<  2)	/* write back memory attribute */
+#define _PAGE_MA_UC		(0x4 <<  2)	/* uncacheable memory attribute */
+#define _PAGE_MA_UCE		(0x5 <<  2)	/* UC exported attribute */
+#define _PAGE_MA_WC		(0x6 <<  2)	/* write coalescing memory attribute */
+#define _PAGE_MA_NAT		(0x7 <<  2)	/* not-a-thing attribute */
+#define _PAGE_MA_MASK		(0x7 <<  2)
+#define _PAGE_PL_0		(0 <<  7)	/* privilege level 0 (kernel) */
+#define _PAGE_PL_1		(1 <<  7)	/* privilege level 1 (unused) */
+#define _PAGE_PL_2		(2 <<  7)	/* privilege level 2 (unused) */
+#define _PAGE_PL_3		(3 <<  7)	/* privilege level 3 (user) */
+#define _PAGE_PL_MASK		(3 <<  7)
+#define _PAGE_AR_R		(0 <<  9)	/* read only */
+#define _PAGE_AR_RX		(1 <<  9)	/* read & execute */
+#define _PAGE_AR_RW		(2 <<  9)	/* read & write */
+#define _PAGE_AR_RWX		(3 <<  9)	/* read, write & execute */
+#define _PAGE_AR_R_RW		(4 <<  9)	/* read / read & write */
+#define _PAGE_AR_RX_RWX		(5 <<  9)	/* read & exec / read, write & exec */
+#define _PAGE_AR_RWX_RW		(6 <<  9)	/* read, write & exec / read & write */
+#define _PAGE_AR_X_RX		(7 <<  9)	/* exec & promote / read & exec */
+#define _PAGE_AR_MASK		(7 <<  9)
+#define _PAGE_AR_SHIFT		9
+#define _PAGE_A			(1 << _PAGE_A_BIT)	/* page accessed bit */
+#define _PAGE_D			(1 << _PAGE_D_BIT)	/* page dirty bit */
+#define _PAGE_PPN_MASK		(((__IA64_UL(1) << IA64_MAX_PHYS_BITS) - 1) & ~0xfffUL)
+#define _PAGE_ED		(__IA64_UL(1) << 52)	/* exception deferral */
+#define _PAGE_PROTNONE		(__IA64_UL(1) << 63)
+
+/* We borrow bit 7 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE	(1 << 7)
+
+#define _PFN_MASK		_PAGE_PPN_MASK
+/* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */
+#define _PAGE_CHG_MASK	(_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED)
+
+#define _PAGE_SIZE_4K	12
+#define _PAGE_SIZE_8K	13
+#define _PAGE_SIZE_16K	14
+#define _PAGE_SIZE_64K	16
+#define _PAGE_SIZE_256K	18
+#define _PAGE_SIZE_1M	20
+#define _PAGE_SIZE_4M	22
+#define _PAGE_SIZE_16M	24
+#define _PAGE_SIZE_64M	26
+#define _PAGE_SIZE_256M	28
+#define _PAGE_SIZE_1G	30
+#define _PAGE_SIZE_4G	32
+
+#define __ACCESS_BITS		_PAGE_ED | _PAGE_A | _PAGE_P | _PAGE_MA_WB
+#define __DIRTY_BITS_NO_ED	_PAGE_A | _PAGE_P | _PAGE_D | _PAGE_MA_WB
+#define __DIRTY_BITS		_PAGE_ED | __DIRTY_BITS_NO_ED
+
+/*
+ * How many pointers will a page table level hold expressed in shift
+ */
+#define PTRS_PER_PTD_SHIFT	(PAGE_SHIFT-3)
+
+/*
+ * Definitions for fourth level:
+ */
+#define PTRS_PER_PTE	(__IA64_UL(1) << (PTRS_PER_PTD_SHIFT))
+
+/*
+ * Definitions for third level:
+ *
+ * PMD_SHIFT determines the size of the area a third-level page table
+ * can map.
+ */
+#define PMD_SHIFT	(PAGE_SHIFT + (PTRS_PER_PTD_SHIFT))
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+#define PTRS_PER_PMD	(1UL << (PTRS_PER_PTD_SHIFT))
+
+#if CONFIG_PGTABLE_LEVELS == 4
+/*
+ * Definitions for second level:
+ *
+ * PUD_SHIFT determines the size of the area a second-level page table
+ * can map.
+ */
+#define PUD_SHIFT	(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
+#define PUD_SIZE	(1UL << PUD_SHIFT)
+#define PUD_MASK	(~(PUD_SIZE-1))
+#define PTRS_PER_PUD	(1UL << (PTRS_PER_PTD_SHIFT))
+#endif
+
+/*
+ * Definitions for first level:
+ *
+ * PGDIR_SHIFT determines what a first-level page table entry can map.
+ */
+#if CONFIG_PGTABLE_LEVELS == 4
+#define PGDIR_SHIFT		(PUD_SHIFT + (PTRS_PER_PTD_SHIFT))
+#else
+#define PGDIR_SHIFT		(PMD_SHIFT + (PTRS_PER_PTD_SHIFT))
+#endif
+#define PGDIR_SIZE		(__IA64_UL(1) << PGDIR_SHIFT)
+#define PGDIR_MASK		(~(PGDIR_SIZE-1))
+#define PTRS_PER_PGD_SHIFT	PTRS_PER_PTD_SHIFT
+#define PTRS_PER_PGD		(1UL << PTRS_PER_PGD_SHIFT)
+#define USER_PTRS_PER_PGD	(5*PTRS_PER_PGD/8)	/* regions 0-4 are user regions */
+
+/*
+ * All the normal masks have the "page accessed" bits on, as any time
+ * they are used, the page is accessed. They are cleared only by the
+ * page-out routines.
+ */
+#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_A)
+#define PAGE_SHARED	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RW)
+#define PAGE_READONLY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
+#define PAGE_COPY	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_R)
+#define PAGE_COPY_EXEC	__pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX)
+#define PAGE_GATE	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX)
+#define PAGE_KERNEL	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX)
+#define PAGE_KERNELRX	__pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX)
+#define PAGE_KERNEL_UC	__pgprot(__DIRTY_BITS  | _PAGE_PL_0 | _PAGE_AR_RWX | \
+				 _PAGE_MA_UC)
+
+# ifndef __ASSEMBLY__
+
+#include <linux/sched/mm.h>	/* for mm_struct */
+#include <linux/bitops.h>
+#include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
+
+/*
+ * Next come the mappings that determine how mmap() protection bits
+ * (PROT_EXEC, PROT_READ, PROT_WRITE, PROT_NONE) get implemented.  The
+ * _P version gets used for a private shared memory segment, the _S
+ * version gets used for a shared memory segment with MAP_SHARED on.
+ * In a private shared memory segment, we do a copy-on-write if a task
+ * attempts to write to the page.
+ */
+	/* xwr */
+#define pgd_ERROR(e)	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
+#if CONFIG_PGTABLE_LEVELS == 4
+#define pud_ERROR(e)	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
+#endif
+#define pmd_ERROR(e)	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
+#define pte_ERROR(e)	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
+
+
+/*
+ * Some definitions to translate between mem_map, PTEs, and page addresses:
+ */
+
+
+/* Quick test to see if ADDR is a (potentially) valid physical address. */
+static inline long
+ia64_phys_addr_valid (unsigned long addr)
+{
+	return (addr & (local_cpu_data->unimpl_pa_mask)) == 0;
+}
+
+/*
+ * Now come the defines and routines to manage and access the three-level
+ * page table.
+ */
+
+
+#define VMALLOC_START		(RGN_BASE(RGN_GATE) + 0x200000000UL)
+#if defined(CONFIG_SPARSEMEM) && defined(CONFIG_SPARSEMEM_VMEMMAP)
+/* SPARSEMEM_VMEMMAP uses half of vmalloc... */
+# define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 10)))
+# define vmemmap		((struct page *)VMALLOC_END)
+#else
+# define VMALLOC_END		(RGN_BASE(RGN_GATE) + (1UL << (4*PAGE_SHIFT - 9)))
+#endif
+
+/* fs/proc/kcore.c */
+#define	kc_vaddr_to_offset(v) ((v) - RGN_BASE(RGN_GATE))
+#define	kc_offset_to_vaddr(o) ((o) + RGN_BASE(RGN_GATE))
+
+#define RGN_MAP_SHIFT (PGDIR_SHIFT + PTRS_PER_PGD_SHIFT - 3)
+#define RGN_MAP_LIMIT	((1UL << RGN_MAP_SHIFT) - PAGE_SIZE)	/* per region addr limit */
+
+#define PFN_PTE_SHIFT	PAGE_SHIFT
+/*
+ * Conversion functions: convert page frame number (pfn) and a protection value to a page
+ * table entry (pte).
+ */
+#define pfn_pte(pfn, pgprot) \
+({ pte_t __pte; pte_val(__pte) = ((pfn) << PAGE_SHIFT) | pgprot_val(pgprot); __pte; })
+
+/* Extract pfn from pte.  */
+#define pte_pfn(_pte)		((pte_val(_pte) & _PFN_MASK) >> PAGE_SHIFT)
+
+#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+
+/* This takes a physical page address that is used by the remapping functions */
+#define mk_pte_phys(physpage, pgprot) \
+({ pte_t __pte; pte_val(__pte) = physpage + pgprot_val(pgprot); __pte; })
+
+#define pte_modify(_pte, newprot) \
+	(__pte((pte_val(_pte) & ~_PAGE_CHG_MASK) | (pgprot_val(newprot) & _PAGE_CHG_MASK)))
+
+#define pte_none(pte) 			(!pte_val(pte))
+#define pte_present(pte)		(pte_val(pte) & (_PAGE_P | _PAGE_PROTNONE))
+#define pte_clear(mm,addr,pte)		(pte_val(*(pte)) = 0UL)
+/* pte_page() returns the "struct page *" corresponding to the PTE: */
+#define pte_page(pte)			virt_to_page(((pte_val(pte) & _PFN_MASK) + PAGE_OFFSET))
+
+#define pmd_none(pmd)			(!pmd_val(pmd))
+#define pmd_bad(pmd)			(!ia64_phys_addr_valid(pmd_val(pmd)))
+#define pmd_present(pmd)		(pmd_val(pmd) != 0UL)
+#define pmd_clear(pmdp)			(pmd_val(*(pmdp)) = 0UL)
+#define pmd_page_vaddr(pmd)		((unsigned long) __va(pmd_val(pmd) & _PFN_MASK))
+#define pmd_pfn(pmd)			((pmd_val(pmd) & _PFN_MASK) >> PAGE_SHIFT)
+#define pmd_page(pmd)			virt_to_page((pmd_val(pmd) + PAGE_OFFSET))
+
+#define pud_none(pud)			(!pud_val(pud))
+#define pud_bad(pud)			(!ia64_phys_addr_valid(pud_val(pud)))
+#define pud_present(pud)		(pud_val(pud) != 0UL)
+#define pud_clear(pudp)			(pud_val(*(pudp)) = 0UL)
+#define pud_pgtable(pud)		((pmd_t *) __va(pud_val(pud) & _PFN_MASK))
+#define pud_page(pud)			virt_to_page((pud_val(pud) + PAGE_OFFSET))
+
+#if CONFIG_PGTABLE_LEVELS == 4
+#define p4d_none(p4d)			(!p4d_val(p4d))
+#define p4d_bad(p4d)			(!ia64_phys_addr_valid(p4d_val(p4d)))
+#define p4d_present(p4d)		(p4d_val(p4d) != 0UL)
+#define p4d_clear(p4dp)			(p4d_val(*(p4dp)) = 0UL)
+#define p4d_pgtable(p4d)		((pud_t *) __va(p4d_val(p4d) & _PFN_MASK))
+#define p4d_page(p4d)			virt_to_page((p4d_val(p4d) + PAGE_OFFSET))
+#endif
+
+/*
+ * The following have defined behavior only work if pte_present() is true.
+ */
+#define pte_write(pte)	((unsigned) (((pte_val(pte) & _PAGE_AR_MASK) >> _PAGE_AR_SHIFT) - 2) <= 4)
+#define pte_exec(pte)		((pte_val(pte) & _PAGE_AR_RX) != 0)
+#define pte_dirty(pte)		((pte_val(pte) & _PAGE_D) != 0)
+#define pte_young(pte)		((pte_val(pte) & _PAGE_A) != 0)
+
+/*
+ * Note: we convert AR_RWX to AR_RX and AR_RW to AR_R by clearing the 2nd bit in the
+ * access rights:
+ */
+#define pte_wrprotect(pte)	(__pte(pte_val(pte) & ~_PAGE_AR_RW))
+#define pte_mkwrite_novma(pte)	(__pte(pte_val(pte) | _PAGE_AR_RW))
+#define pte_mkold(pte)		(__pte(pte_val(pte) & ~_PAGE_A))
+#define pte_mkyoung(pte)	(__pte(pte_val(pte) | _PAGE_A))
+#define pte_mkclean(pte)	(__pte(pte_val(pte) & ~_PAGE_D))
+#define pte_mkdirty(pte)	(__pte(pte_val(pte) | _PAGE_D))
+#define pte_mkhuge(pte)		(__pte(pte_val(pte)))
+
+/*
+ * Because ia64's Icache and Dcache is not coherent (on a cpu), we need to
+ * sync icache and dcache when we insert *new* executable page.
+ *  __ia64_sync_icache_dcache() check Pg_arch_1 bit and flush icache
+ * if necessary.
+ *
+ *  set_pte() is also called by the kernel, but we can expect that the kernel
+ *  flushes icache explicitly if necessary.
+ */
+#define pte_present_exec_user(pte)\
+	((pte_val(pte) & (_PAGE_P | _PAGE_PL_MASK | _PAGE_AR_RX)) == \
+		(_PAGE_P | _PAGE_PL_3 | _PAGE_AR_RX))
+
+extern void __ia64_sync_icache_dcache(pte_t pteval);
+static inline void set_pte(pte_t *ptep, pte_t pteval)
+{
+	/* page is present && page is user  && page is executable
+	 * && (page swapin or new page or page migration
+	 *	|| copy_on_write with page copying.)
+	 */
+	if (pte_present_exec_user(pteval) &&
+	    (!pte_present(*ptep) ||
+		pte_pfn(*ptep) != pte_pfn(pteval)))
+		/* load_module() calles flush_icache_range() explicitly*/
+		__ia64_sync_icache_dcache(pteval);
+	*ptep = pteval;
+}
+
+/*
+ * Make page protection values cacheable, uncacheable, or write-
+ * combining.  Note that "protection" is really a misnomer here as the
+ * protection value contains the memory attribute bits, dirty bits, and
+ * various other bits as well.
+ */
+#define pgprot_cacheable(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WB)
+#define pgprot_noncached(prot)		__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_UC)
+#define pgprot_writecombine(prot)	__pgprot((pgprot_val(prot) & ~_PAGE_MA_MASK) | _PAGE_MA_WC)
+
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+				     unsigned long size, pgprot_t vma_prot);
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+
+static inline unsigned long
+pgd_index (unsigned long address)
+{
+	unsigned long region = address >> 61;
+	unsigned long l1index = (address >> PGDIR_SHIFT) & ((PTRS_PER_PGD >> 3) - 1);
+
+	return (region << (PAGE_SHIFT - 6)) | l1index;
+}
+#define pgd_index pgd_index
+
+/*
+ * In the kernel's mapped region we know everything is in region number 5, so
+ * as an optimisation its PGD already points to the area for that region.
+ * However, this also means that we cannot use pgd_index() and we must
+ * never add the region here.
+ */
+#define pgd_offset_k(addr) \
+	(init_mm.pgd + (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)))
+
+/* Look up a pgd entry in the gate area.  On IA-64, the gate-area
+   resides in the kernel-mapped segment, hence we use pgd_offset_k()
+   here.  */
+#define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)
+
+/* atomic versions of the some PTE manipulations: */
+
+static inline int
+ptep_test_and_clear_young (struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+#ifdef CONFIG_SMP
+	if (!pte_young(*ptep))
+		return 0;
+	return test_and_clear_bit(_PAGE_A_BIT, ptep);
+#else
+	pte_t pte = *ptep;
+	if (!pte_young(pte))
+		return 0;
+	set_pte_at(vma->vm_mm, addr, ptep, pte_mkold(pte));
+	return 1;
+#endif
+}
+
+static inline pte_t
+ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+#ifdef CONFIG_SMP
+	return __pte(xchg((long *) ptep, 0));
+#else
+	pte_t pte = *ptep;
+	pte_clear(mm, addr, ptep);
+	return pte;
+#endif
+}
+
+static inline void
+ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+#ifdef CONFIG_SMP
+	unsigned long new, old;
+
+	do {
+		old = pte_val(*ptep);
+		new = pte_val(pte_wrprotect(__pte (old)));
+	} while (cmpxchg((unsigned long *) ptep, old, new) != old);
+#else
+	pte_t old_pte = *ptep;
+	set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
+#endif
+}
+
+static inline int
+pte_same (pte_t a, pte_t b)
+{
+	return pte_val(a) == pte_val(b);
+}
+
+#define update_mmu_cache_range(vmf, vma, address, ptep, nr) do { } while (0)
+#define update_mmu_cache(vma, address, ptep) do { } while (0)
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+extern void paging_init (void);
+
+/*
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
+ *
+ * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of
+ *	 bits in the swap-type field of the swap pte.  It would be nice to
+ *	 enforce that, but we can't easily include <linux/swap.h> here.
+ *	 (Of course, better still would be to define MAX_SWAPFILES_SHIFT here...).
+ *
+ * Format of swap pte:
+ *	bit   0   : present bit (must be zero)
+ *	bits  1- 6: swap type
+ *	bit   7   : exclusive marker
+ *	bits  8-62: swap offset
+ *	bit  63   : _PAGE_PROTNONE bit
+ */
+#define __swp_type(entry)		(((entry).val >> 1) & 0x3f)
+#define __swp_offset(entry)		(((entry).val << 1) >> 9)
+#define __swp_entry(type, offset)	((swp_entry_t) { ((type & 0x3f) << 1) | \
+							 ((long) (offset) << 8) })
+#define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
+
+static inline int pte_swp_exclusive(pte_t pte)
+{
+	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
+}
+
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
+	return pte;
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
+	return pte;
+}
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+extern unsigned long empty_zero_page[PAGE_SIZE/sizeof(unsigned long)];
+extern struct page *zero_page_memmap_ptr;
+#define ZERO_PAGE(vaddr) (zero_page_memmap_ptr)
+
+/* We provide our own get_unmapped_area to cope with VA holes for userland */
+#define HAVE_ARCH_UNMAPPED_AREA
+
+#ifdef CONFIG_HUGETLB_PAGE
+#define HUGETLB_PGDIR_SHIFT	(HPAGE_SHIFT + 2*(PAGE_SHIFT-3))
+#define HUGETLB_PGDIR_SIZE	(__IA64_UL(1) << HUGETLB_PGDIR_SHIFT)
+#define HUGETLB_PGDIR_MASK	(~(HUGETLB_PGDIR_SIZE-1))
+#endif
+
+
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+/*
+ * Update PTEP with ENTRY, which is guaranteed to be a less
+ * restrictive PTE.  That is, ENTRY may have the ACCESSED, DIRTY, and
+ * WRITABLE bits turned on, when the value at PTEP did not.  The
+ * WRITABLE bit may only be turned if SAFELY_WRITABLE is TRUE.
+ *
+ * SAFELY_WRITABLE is TRUE if we can update the value at PTEP without
+ * having to worry about races.  On SMP machines, there are only two
+ * cases where this is true:
+ *
+ *	(1) *PTEP has the PRESENT bit turned OFF
+ *	(2) ENTRY has the DIRTY bit turned ON
+ *
+ * On ia64, we could implement this routine with a cmpxchg()-loop
+ * which ORs in the _PAGE_A/_PAGE_D bit if they're set in ENTRY.
+ * However, like on x86, we can get a more streamlined version by
+ * observing that it is OK to drop ACCESSED bit updates when
+ * SAFELY_WRITABLE is FALSE.  Besides being rare, all that would do is
+ * result in an extra Access-bit fault, which would then turn on the
+ * ACCESSED bit in the low-level fault handler (iaccess_bit or
+ * daccess_bit in ivt.S).
+ */
+#ifdef CONFIG_SMP
+# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
+({									\
+	int __changed = !pte_same(*(__ptep), __entry);			\
+	if (__changed && __safely_writable) {				\
+		set_pte(__ptep, __entry);				\
+		flush_tlb_page(__vma, __addr);				\
+	}								\
+	__changed;							\
+})
+#else
+# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
+({									\
+	int __changed = !pte_same(*(__ptep), __entry);			\
+	if (__changed) {						\
+		set_pte_at((__vma)->vm_mm, (__addr), __ptep, __entry);	\
+		flush_tlb_page(__vma, __addr);				\
+	}								\
+	__changed;							\
+})
+#endif
+# endif /* !__ASSEMBLY__ */
+
+/*
+ * Identity-mapped regions use a large page size.  We'll call such large pages
+ * "granules".  If you can think of a better name that's unambiguous, let me
+ * know...
+ */
+#if defined(CONFIG_IA64_GRANULE_64MB)
+# define IA64_GRANULE_SHIFT	_PAGE_SIZE_64M
+#elif defined(CONFIG_IA64_GRANULE_16MB)
+# define IA64_GRANULE_SHIFT	_PAGE_SIZE_16M
+#endif
+#define IA64_GRANULE_SIZE	(1 << IA64_GRANULE_SHIFT)
+/*
+ * log2() of the page size we use to map the kernel image (IA64_TR_KERNEL):
+ */
+#define KERNEL_TR_PAGE_SHIFT	_PAGE_SIZE_64M
+#define KERNEL_TR_PAGE_SIZE	(1 << KERNEL_TR_PAGE_SHIFT)
+
+/* These tell get_user_pages() that the first gate page is accessible from user-level.  */
+#define FIXADDR_USER_START	GATE_ADDR
+#ifdef HAVE_BUGGY_SEGREL
+# define FIXADDR_USER_END	(GATE_ADDR + 2*PAGE_SIZE)
+#else
+# define FIXADDR_USER_END	(GATE_ADDR + 2*PERCPU_PAGE_SIZE)
+#endif
+
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
+#define __HAVE_ARCH_PTEP_SET_WRPROTECT
+#define __HAVE_ARCH_PTE_SAME
+#define __HAVE_ARCH_PGD_OFFSET_GATE
+
+
+#if CONFIG_PGTABLE_LEVELS == 3
+#include <asm-generic/pgtable-nopud.h>
+#endif
+#include <asm-generic/pgtable-nop4d.h>
+
+#endif /* _ASM_IA64_PGTABLE_H */