Initial import

1 files changed, 511 insertions, 0 deletions

diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
new file mode 100644
index 000000000..0a183756d
--- /dev/null
+++ b/arch/parisc/include/asm/pgtable.h
@@ -0,0 +1,511 @@
+#ifndef _PARISC_PGTABLE_H
+#define _PARISC_PGTABLE_H
+
+#include <asm-generic/4level-fixup.h>
+
+#include <asm/fixmap.h>
+
+#ifndef __ASSEMBLY__
+/*
+ * we simulate an x86-style page table for the linux mm code
+ */
+
+#include <linux/bitops.h>
+#include <linux/spinlock.h>
+#include <linux/mm_types.h>
+#include <asm/processor.h>
+#include <asm/cache.h>
+
+extern spinlock_t pa_dbit_lock;
+
+/*
+ * kern_addr_valid(ADDR) tests if ADDR is pointing to valid kernel
+ * memory.  For the return value to be meaningful, ADDR must be >=
+ * PAGE_OFFSET.  This operation can be relatively expensive (e.g.,
+ * require a hash-, or multi-level tree-lookup or something of that
+ * sort) but it guarantees to return TRUE only if accessing the page
+ * at that address does not cause an error.  Note that there may be
+ * addresses for which kern_addr_valid() returns FALSE even though an
+ * access would not cause an error (e.g., this is typically true for
+ * memory mapped I/O regions.
+ *
+ * XXX Need to implement this for parisc.
+ */
+#define kern_addr_valid(addr)	(1)
+
+/* Certain architectures need to do special things when PTEs
+ * within a page table are directly modified.  Thus, the following
+ * hook is made available.
+ */
+#define set_pte(pteptr, pteval)                                 \
+        do{                                                     \
+                *(pteptr) = (pteval);                           \
+        } while(0)
+
+extern void purge_tlb_entries(struct mm_struct *, unsigned long);
+
+#define set_pte_at(mm, addr, ptep, pteval)                      \
+	do {                                                    \
+		unsigned long flags;				\
+		spin_lock_irqsave(&pa_dbit_lock, flags);	\
+		set_pte(ptep, pteval);                          \
+		purge_tlb_entries(mm, addr);                    \
+		spin_unlock_irqrestore(&pa_dbit_lock, flags);	\
+	} while (0)
+
+#endif /* !__ASSEMBLY__ */
+
+#include <asm/page.h>
+
+#define pte_ERROR(e) \
+	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+#define pmd_ERROR(e) \
+	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, (unsigned long)pmd_val(e))
+#define pgd_ERROR(e) \
+	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, (unsigned long)pgd_val(e))
+
+/* This is the size of the initially mapped kernel memory */
+#define KERNEL_INITIAL_ORDER	24	/* 0 to 1<<24 = 16MB */
+#define KERNEL_INITIAL_SIZE	(1 << KERNEL_INITIAL_ORDER)
+
+#if CONFIG_PGTABLE_LEVELS == 3
+#define PGD_ORDER	1 /* Number of pages per pgd */
+#define PMD_ORDER	1 /* Number of pages per pmd */
+#define PGD_ALLOC_ORDER	2 /* first pgd contains pmd */
+#else
+#define PGD_ORDER	1 /* Number of pages per pgd */
+#define PGD_ALLOC_ORDER	PGD_ORDER
+#endif
+
+/* Definitions for 3rd level (we use PLD here for Page Lower directory
+ * because PTE_SHIFT is used lower down to mean shift that has to be
+ * done to get usable bits out of the PTE) */
+#define PLD_SHIFT	PAGE_SHIFT
+#define PLD_SIZE	PAGE_SIZE
+#define BITS_PER_PTE	(PAGE_SHIFT - BITS_PER_PTE_ENTRY)
+#define PTRS_PER_PTE    (1UL << BITS_PER_PTE)
+
+/* Definitions for 2nd level */
+#define pgtable_cache_init()	do { } while (0)
+
+#define PMD_SHIFT       (PLD_SHIFT + BITS_PER_PTE)
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+#if CONFIG_PGTABLE_LEVELS == 3
+#define BITS_PER_PMD	(PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
+#else
+#define __PAGETABLE_PMD_FOLDED
+#define BITS_PER_PMD	0
+#endif
+#define PTRS_PER_PMD    (1UL << BITS_PER_PMD)
+
+/* Definitions for 1st level */
+#define PGDIR_SHIFT	(PMD_SHIFT + BITS_PER_PMD)
+#if (PGDIR_SHIFT + PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY) > BITS_PER_LONG
+#define BITS_PER_PGD	(BITS_PER_LONG - PGDIR_SHIFT)
+#else
+#define BITS_PER_PGD	(PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY)
+#endif
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+#define PTRS_PER_PGD    (1UL << BITS_PER_PGD)
+#define USER_PTRS_PER_PGD       PTRS_PER_PGD
+
+#ifdef CONFIG_64BIT
+#define MAX_ADDRBITS	(PGDIR_SHIFT + BITS_PER_PGD)
+#define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
+#define SPACEID_SHIFT	(MAX_ADDRBITS - 32)
+#else
+#define MAX_ADDRBITS	(BITS_PER_LONG)
+#define MAX_ADDRESS	(1UL << MAX_ADDRBITS)
+#define SPACEID_SHIFT	0
+#endif
+
+/* This calculates the number of initial pages we need for the initial
+ * page tables */
+#if (KERNEL_INITIAL_ORDER) >= (PMD_SHIFT)
+# define PT_INITIAL	(1 << (KERNEL_INITIAL_ORDER - PMD_SHIFT))
+#else
+# define PT_INITIAL	(1)  /* all initial PTEs fit into one page */
+#endif
+
+/*
+ * pgd entries used up by user/kernel:
+ */
+
+#define FIRST_USER_ADDRESS	0UL
+
+/* NB: The tlb miss handlers make certain assumptions about the order */
+/*     of the following bits, so be careful (One example, bits 25-31  */
+/*     are moved together in one instruction).                        */
+
+#define _PAGE_READ_BIT     31   /* (0x001) read access allowed */
+#define _PAGE_WRITE_BIT    30   /* (0x002) write access allowed */
+#define _PAGE_EXEC_BIT     29   /* (0x004) execute access allowed */
+#define _PAGE_GATEWAY_BIT  28   /* (0x008) privilege promotion allowed */
+#define _PAGE_DMB_BIT      27   /* (0x010) Data Memory Break enable (B bit) */
+#define _PAGE_DIRTY_BIT    26   /* (0x020) Page Dirty (D bit) */
+#define _PAGE_REFTRAP_BIT  25   /* (0x040) Page Ref. Trap enable (T bit) */
+#define _PAGE_NO_CACHE_BIT 24   /* (0x080) Uncached Page (U bit) */
+#define _PAGE_ACCESSED_BIT 23   /* (0x100) Software: Page Accessed */
+#define _PAGE_PRESENT_BIT  22   /* (0x200) Software: translation valid */
+/* bit 21 was formerly the FLUSH bit but is now unused */
+#define _PAGE_USER_BIT     20   /* (0x800) Software: User accessible page */
+
+/* N.B. The bits are defined in terms of a 32 bit word above, so the */
+/*      following macro is ok for both 32 and 64 bit.                */
+
+#define xlate_pabit(x) (31 - x)
+
+/* this defines the shift to the usable bits in the PTE it is set so
+ * that the valid bits _PAGE_PRESENT_BIT and _PAGE_USER_BIT are set
+ * to zero */
+#define PTE_SHIFT	   	xlate_pabit(_PAGE_USER_BIT)
+
+/* PFN_PTE_SHIFT defines the shift of a PTE value to access the PFN field */
+#define PFN_PTE_SHIFT		12
+
+#define _PAGE_READ     (1 << xlate_pabit(_PAGE_READ_BIT))
+#define _PAGE_WRITE    (1 << xlate_pabit(_PAGE_WRITE_BIT))
+#define _PAGE_RW       (_PAGE_READ | _PAGE_WRITE)
+#define _PAGE_EXEC     (1 << xlate_pabit(_PAGE_EXEC_BIT))
+#define _PAGE_GATEWAY  (1 << xlate_pabit(_PAGE_GATEWAY_BIT))
+#define _PAGE_DMB      (1 << xlate_pabit(_PAGE_DMB_BIT))
+#define _PAGE_DIRTY    (1 << xlate_pabit(_PAGE_DIRTY_BIT))
+#define _PAGE_REFTRAP  (1 << xlate_pabit(_PAGE_REFTRAP_BIT))
+#define _PAGE_NO_CACHE (1 << xlate_pabit(_PAGE_NO_CACHE_BIT))
+#define _PAGE_ACCESSED (1 << xlate_pabit(_PAGE_ACCESSED_BIT))
+#define _PAGE_PRESENT  (1 << xlate_pabit(_PAGE_PRESENT_BIT))
+#define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
+
+#define _PAGE_TABLE	(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE |  _PAGE_DIRTY | _PAGE_ACCESSED)
+#define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_KERNEL_RO	(_PAGE_PRESENT | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define _PAGE_KERNEL_EXEC	(_PAGE_KERNEL_RO | _PAGE_EXEC)
+#define _PAGE_KERNEL_RWX	(_PAGE_KERNEL_EXEC | _PAGE_WRITE)
+#define _PAGE_KERNEL		(_PAGE_KERNEL_RO | _PAGE_WRITE)
+
+/* The pgd/pmd contains a ptr (in phys addr space); since all pgds/pmds
+ * are page-aligned, we don't care about the PAGE_OFFSET bits, except
+ * for a few meta-information bits, so we shift the address to be
+ * able to effectively address 40/42/44-bits of physical address space
+ * depending on 4k/16k/64k PAGE_SIZE */
+#define _PxD_PRESENT_BIT   31
+#define _PxD_ATTACHED_BIT  30
+#define _PxD_VALID_BIT     29
+
+#define PxD_FLAG_PRESENT  (1 << xlate_pabit(_PxD_PRESENT_BIT))
+#define PxD_FLAG_ATTACHED (1 << xlate_pabit(_PxD_ATTACHED_BIT))
+#define PxD_FLAG_VALID    (1 << xlate_pabit(_PxD_VALID_BIT))
+#define PxD_FLAG_MASK     (0xf)
+#define PxD_FLAG_SHIFT    (4)
+#define PxD_VALUE_SHIFT   (8) /* (PAGE_SHIFT-PxD_FLAG_SHIFT) */
+
+#ifndef __ASSEMBLY__
+
+#define PAGE_NONE	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
+#define PAGE_SHARED	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_ACCESSED)
+/* Others seem to make this executable, I don't know if that's correct
+   or not.  The stack is mapped this way though so this is necessary
+   in the short term - dhd@linuxcare.com, 2000-08-08 */
+#define PAGE_READONLY	__pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_ACCESSED)
+#define PAGE_WRITEONLY  __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITE | _PAGE_ACCESSED)
+#define PAGE_EXECREAD   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_EXEC |_PAGE_ACCESSED)
+#define PAGE_COPY       PAGE_EXECREAD
+#define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC |_PAGE_ACCESSED)
+#define PAGE_KERNEL	__pgprot(_PAGE_KERNEL)
+#define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
+#define PAGE_KERNEL_RWX	__pgprot(_PAGE_KERNEL_RWX)
+#define PAGE_KERNEL_RO	__pgprot(_PAGE_KERNEL_RO)
+#define PAGE_KERNEL_UNC	__pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
+#define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_GATEWAY| _PAGE_READ)
+
+
+/*
+ * We could have an execute only page using "gateway - promote to priv
+ * level 3", but that is kind of silly. So, the way things are defined
+ * now, we must always have read permission for pages with execute
+ * permission. For the fun of it we'll go ahead and support write only
+ * pages.
+ */
+
+	 /*xwr*/
+#define __P000  PAGE_NONE
+#define __P001  PAGE_READONLY
+#define __P010  __P000 /* copy on write */
+#define __P011  __P001 /* copy on write */
+#define __P100  PAGE_EXECREAD
+#define __P101  PAGE_EXECREAD
+#define __P110  __P100 /* copy on write */
+#define __P111  __P101 /* copy on write */
+
+#define __S000  PAGE_NONE
+#define __S001  PAGE_READONLY
+#define __S010  PAGE_WRITEONLY
+#define __S011  PAGE_SHARED
+#define __S100  PAGE_EXECREAD
+#define __S101  PAGE_EXECREAD
+#define __S110  PAGE_RWX
+#define __S111  PAGE_RWX
+
+
+extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */
+
+/* initial page tables for 0-8MB for kernel */
+
+extern pte_t pg0[];
+
+/* zero page used for uninitialized stuff */
+
+extern unsigned long *empty_zero_page;
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+#define pte_none(x)     (pte_val(x) == 0)
+#define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
+#define pte_clear(mm,addr,xp)	do { pte_val(*(xp)) = 0; } while (0)
+
+#define pmd_flag(x)	(pmd_val(x) & PxD_FLAG_MASK)
+#define pmd_address(x)	((unsigned long)(pmd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
+#define pgd_flag(x)	(pgd_val(x) & PxD_FLAG_MASK)
+#define pgd_address(x)	((unsigned long)(pgd_val(x) &~ PxD_FLAG_MASK) << PxD_VALUE_SHIFT)
+
+#if CONFIG_PGTABLE_LEVELS == 3
+/* The first entry of the permanent pmd is not there if it contains
+ * the gateway marker */
+#define pmd_none(x)	(!pmd_val(x) || pmd_flag(x) == PxD_FLAG_ATTACHED)
+#else
+#define pmd_none(x)	(!pmd_val(x))
+#endif
+#define pmd_bad(x)	(!(pmd_flag(x) & PxD_FLAG_VALID))
+#define pmd_present(x)	(pmd_flag(x) & PxD_FLAG_PRESENT)
+static inline void pmd_clear(pmd_t *pmd) {
+#if CONFIG_PGTABLE_LEVELS == 3
+	if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
+		/* This is the entry pointing to the permanent pmd
+		 * attached to the pgd; cannot clear it */
+		__pmd_val_set(*pmd, PxD_FLAG_ATTACHED);
+	else
+#endif
+		__pmd_val_set(*pmd,  0);
+}
+
+
+
+#if CONFIG_PGTABLE_LEVELS == 3
+#define pgd_page_vaddr(pgd) ((unsigned long) __va(pgd_address(pgd)))
+#define pgd_page(pgd)	virt_to_page((void *)pgd_page_vaddr(pgd))
+
+/* For 64 bit we have three level tables */
+
+#define pgd_none(x)     (!pgd_val(x))
+#define pgd_bad(x)      (!(pgd_flag(x) & PxD_FLAG_VALID))
+#define pgd_present(x)  (pgd_flag(x) & PxD_FLAG_PRESENT)
+static inline void pgd_clear(pgd_t *pgd) {
+#if CONFIG_PGTABLE_LEVELS == 3
+	if(pgd_flag(*pgd) & PxD_FLAG_ATTACHED)
+		/* This is the permanent pmd attached to the pgd; cannot
+		 * free it */
+		return;
+#endif
+	__pgd_val_set(*pgd, 0);
+}
+#else
+/*
+ * The "pgd_xxx()" functions here are trivial for a folded two-level
+ * setup: the pgd is never bad, and a pmd always exists (as it's folded
+ * into the pgd entry)
+ */
+static inline int pgd_none(pgd_t pgd)		{ return 0; }
+static inline int pgd_bad(pgd_t pgd)		{ return 0; }
+static inline int pgd_present(pgd_t pgd)	{ return 1; }
+static inline void pgd_clear(pgd_t * pgdp)	{ }
+#endif
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
+static inline int pte_young(pte_t pte)		{ return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_write(pte_t pte)		{ return pte_val(pte) & _PAGE_WRITE; }
+static inline int pte_special(pte_t pte)	{ return 0; }
+
+static inline pte_t pte_mkclean(pte_t pte)	{ pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
+static inline pte_t pte_mkold(pte_t pte)	{ pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
+static inline pte_t pte_wrprotect(pte_t pte)	{ pte_val(pte) &= ~_PAGE_WRITE; return pte; }
+static inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= _PAGE_DIRTY; return pte; }
+static inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= _PAGE_ACCESSED; return pte; }
+static inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) |= _PAGE_WRITE; return pte; }
+static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+#define __mk_pte(addr,pgprot) \
+({									\
+	pte_t __pte;							\
+									\
+	pte_val(__pte) = ((((addr)>>PAGE_SHIFT)<<PFN_PTE_SHIFT) + pgprot_val(pgprot));	\
+									\
+	__pte;								\
+})
+
+#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+
+static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
+{
+	pte_t pte;
+	pte_val(pte) = (pfn << PFN_PTE_SHIFT) | pgprot_val(pgprot);
+	return pte;
+}
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{ pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
+
+/* Permanent address of a page.  On parisc we don't have highmem. */
+
+#define pte_pfn(x)		(pte_val(x) >> PFN_PTE_SHIFT)
+
+#define pte_page(pte)		(pfn_to_page(pte_pfn(pte)))
+
+#define pmd_page_vaddr(pmd)	((unsigned long) __va(pmd_address(pmd)))
+
+#define __pmd_page(pmd) ((unsigned long) __va(pmd_address(pmd)))
+#define pmd_page(pmd)	virt_to_page((void *)__pmd_page(pmd))
+
+#define pgd_index(address) ((address) >> PGDIR_SHIFT)
+
+/* to find an entry in a page-table-directory */
+#define pgd_offset(mm, address) \
+((mm)->pgd + ((address) >> PGDIR_SHIFT))
+
+/* to find an entry in a kernel page-table-directory */
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+
+/* Find an entry in the second-level page table.. */
+
+#if CONFIG_PGTABLE_LEVELS == 3
+#define pmd_offset(dir,address) \
+((pmd_t *) pgd_page_vaddr(*(dir)) + (((address)>>PMD_SHIFT) & (PTRS_PER_PMD-1)))
+#else
+#define pmd_offset(dir,addr) ((pmd_t *) dir)
+#endif
+
+/* Find an entry in the third-level page table.. */ 
+#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
+#define pte_offset_kernel(pmd, address) \
+	((pte_t *) pmd_page_vaddr(*(pmd)) + pte_index(address))
+#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
+#define pte_unmap(pte) do { } while (0)
+
+#define pte_unmap(pte)			do { } while (0)
+#define pte_unmap_nested(pte)		do { } while (0)
+
+extern void paging_init (void);
+
+/* Used for deferring calls to flush_dcache_page() */
+
+#define PG_dcache_dirty         PG_arch_1
+
+extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t *);
+
+/* Encode and de-code a swap entry */
+
+#define __swp_type(x)                     ((x).val & 0x1f)
+#define __swp_offset(x)                   ( (((x).val >> 6) &  0x7) | \
+					  (((x).val >> 8) & ~0x7) )
+#define __swp_entry(type, offset)         ((swp_entry_t) { (type) | \
+					    ((offset &  0x7) << 6) | \
+					    ((offset & ~0x7) << 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 ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+	pte_t pte;
+	unsigned long flags;
+
+	if (!pte_young(*ptep))
+		return 0;
+
+	spin_lock_irqsave(&pa_dbit_lock, flags);
+	pte = *ptep;
+	if (!pte_young(pte)) {
+		spin_unlock_irqrestore(&pa_dbit_lock, flags);
+		return 0;
+	}
+	set_pte(ptep, pte_mkold(pte));
+	purge_tlb_entries(vma->vm_mm, addr);
+	spin_unlock_irqrestore(&pa_dbit_lock, flags);
+	return 1;
+}
+
+struct mm_struct;
+static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+	pte_t old_pte;
+	unsigned long flags;
+
+	spin_lock_irqsave(&pa_dbit_lock, flags);
+	old_pte = *ptep;
+	pte_clear(mm,addr,ptep);
+	purge_tlb_entries(mm, addr);
+	spin_unlock_irqrestore(&pa_dbit_lock, flags);
+
+	return old_pte;
+}
+
+static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&pa_dbit_lock, flags);
+	set_pte(ptep, pte_wrprotect(*ptep));
+	purge_tlb_entries(mm, addr);
+	spin_unlock_irqrestore(&pa_dbit_lock, flags);
+}
+
+#define pte_same(A,B)	(pte_val(A) == pte_val(B))
+
+#endif /* !__ASSEMBLY__ */
+
+
+/* TLB page size encoding - see table 3-1 in parisc20.pdf */
+#define _PAGE_SIZE_ENCODING_4K		0
+#define _PAGE_SIZE_ENCODING_16K		1
+#define _PAGE_SIZE_ENCODING_64K		2
+#define _PAGE_SIZE_ENCODING_256K	3
+#define _PAGE_SIZE_ENCODING_1M		4
+#define _PAGE_SIZE_ENCODING_4M		5
+#define _PAGE_SIZE_ENCODING_16M		6
+#define _PAGE_SIZE_ENCODING_64M		7
+
+#if defined(CONFIG_PARISC_PAGE_SIZE_4KB)
+# define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_4K
+#elif defined(CONFIG_PARISC_PAGE_SIZE_16KB)
+# define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_16K
+#elif defined(CONFIG_PARISC_PAGE_SIZE_64KB)
+# define _PAGE_SIZE_ENCODING_DEFAULT _PAGE_SIZE_ENCODING_64K
+#endif
+
+
+#define pgprot_noncached(prot) __pgprot(pgprot_val(prot) | _PAGE_NO_CACHE)
+
+/* We provide our own get_unmapped_area to provide cache coherency */
+
+#define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+
+#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
+#include <asm-generic/pgtable.h>
+
+#endif /* _PARISC_PGTABLE_H */