arch: Remove Itanium (IA-64) architecture

The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 0 insertions, 545 deletions

diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
deleted file mode 100644
index 9be2d2ba6016..000000000000
--- a/arch/ia64/include/asm/pgtable.h
+++ /dev/null
@@ -1,545 +0,0 @@
-/* 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 */