1 files changed, 522 insertions, 0 deletions

diff --git a/include/asm-parisc/pgtable.h b/include/asm-parisc/pgtable.h
new file mode 100644
index 000000000000..af353a9bce21
--- /dev/null
+++ b/include/asm-parisc/pgtable.h
@@ -0,0 +1,522 @@
+#ifndef _PARISC_PGTABLE_H
+#define _PARISC_PGTABLE_H
+
+#include <asm-generic/4level-fixup.h>
+
+#include <linux/config.h>
+#include <asm/fixmap.h>
+
+#ifndef __ASSEMBLY__
+/*
+ * we simulate an x86-style page table for the linux mm code
+ */
+
+#include <linux/spinlock.h>
+#include <asm/processor.h>
+#include <asm/cache.h>
+#include <asm/bitops.h>
+
+/*
+ * 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)
+#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+
+#endif /* !__ASSEMBLY__ */
+
+#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))
+
+ /* Note: If you change ISTACK_SIZE, you need to change the corresponding
+  * values in vmlinux.lds and vmlinux64.lds (init_istack section). Also,
+  * the "order" and size need to agree.
+  */
+
+#define  ISTACK_SIZE  32768 /* Interrupt Stack Size */
+#define  ISTACK_ORDER 3
+
+/* This is the size of the initially mapped kernel memory (i.e. currently
+ * 0 to 1<<23 == 8MB */
+#ifdef CONFIG_64BIT
+#define KERNEL_INITIAL_ORDER    24
+#else
+#define KERNEL_INITIAL_ORDER    23
+#endif
+#define KERNEL_INITIAL_SIZE     (1 << KERNEL_INITIAL_ORDER)
+
+#ifdef CONFIG_64BIT
+#define PT_NLEVELS      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 PT_NLEVELS      2
+#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 PT_NLEVELS == 3
+#define BITS_PER_PMD    (PAGE_SHIFT + PMD_ORDER - BITS_PER_PMD_ENTRY)
+#else
+#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)
+#define BITS_PER_PGD    (PAGE_SHIFT + PGD_ORDER - BITS_PER_PGD_ENTRY)
+#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
+
+#define MAX_ADDRBITS    (PGDIR_SHIFT + BITS_PER_PGD)
+#define MAX_ADDRESS     (1UL << MAX_ADDRBITS)
+
+#define SPACEID_SHIFT (MAX_ADDRBITS - 32)
+
+/* This calculates the number of initial pages we need for the initial
+ * page tables */
+#define PT_INITIAL      (1 << (KERNEL_INITIAL_ORDER - PMD_SHIFT))
+
+/*
+ * pgd entries used up by user/kernel:
+ */
+
+#define FIRST_USER_PGD_NR       0
+
+#ifndef __ASSEMBLY__
+extern  void *vmalloc_start;
+#define PCXL_DMA_MAP_SIZE   (8*1024*1024)
+#define VMALLOC_START   ((unsigned long)vmalloc_start)
+/* this is a fixmap remnant, see fixmap.h */
+#define VMALLOC_END     (KERNEL_MAP_END)
+#endif
+
+/* 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_FILE_BIT  _PAGE_DIRTY_BIT /* overload this 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 */
+#define _PAGE_FLUSH_BIT    21   /* (0x400) Software: translation valid */
+                                /*             for cache flushing only */
+#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)
+
+/* this is how many bits may be used by the file functions */
+#define PTE_FILE_MAX_BITS       (BITS_PER_LONG - PTE_SHIFT)
+
+#define pte_to_pgoff(pte) (pte_val(pte) >> PTE_SHIFT)
+#define pgoff_to_pte(off) ((pte_t) { ((off) << PTE_SHIFT) | _PAGE_FILE })
+
+#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_FLUSH    (1 << xlate_pabit(_PAGE_FLUSH_BIT))
+#define _PAGE_USER     (1 << xlate_pabit(_PAGE_USER_BIT))
+#define _PAGE_FILE     (1 << xlate_pabit(_PAGE_FILE_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    (_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_WRITE | _PAGE_DIRTY | _PAGE_ACCESSED)
+
+/* 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-bits of physical address space. */
+#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)
+
+#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_RO  __pgprot(_PAGE_PRESENT | _PAGE_EXEC | _PAGE_READ | _PAGE_DIRTY | _PAGE_ACCESSED)
+#define PAGE_KERNEL_UNC __pgprot(_PAGE_KERNEL | _PAGE_NO_CACHE)
+#define PAGE_GATEWAY    __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED | _PAGE_GATEWAY| _PAGE_READ)
+#define PAGE_FLUSH      __pgprot(_PAGE_FLUSH)
+
+
+/*
+ * 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) || (pte_val(x) & _PAGE_FLUSH))
+#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)
+
+#ifdef CONFIG_64BIT
+/* 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) {
+#ifdef CONFIG_64BIT
+        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 PT_NLEVELS == 3
+#define pgd_page(pgd) ((unsigned long) __va(pgd_address(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) {
+#ifdef CONFIG_64BIT
+        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)
+ */
+extern inline int pgd_none(pgd_t pgd)           { return 0; }
+extern inline int pgd_bad(pgd_t pgd)            { return 0; }
+extern inline int pgd_present(pgd_t pgd)        { return 1; }
+extern inline void pgd_clear(pgd_t * pgdp)      { }
+#endif
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+extern inline int pte_read(pte_t pte)           { return pte_val(pte) & _PAGE_READ; }
+extern inline int pte_dirty(pte_t pte)          { return pte_val(pte) & _PAGE_DIRTY; }
+extern inline int pte_young(pte_t pte)          { return pte_val(pte) & _PAGE_ACCESSED; }
+extern inline int pte_write(pte_t pte)          { return pte_val(pte) & _PAGE_WRITE; }
+extern inline int pte_file(pte_t pte)           { return pte_val(pte) & _PAGE_FILE; }
+extern inline int pte_user(pte_t pte)           { return pte_val(pte) & _PAGE_USER; }
+
+extern inline pte_t pte_rdprotect(pte_t pte)    { pte_val(pte) &= ~_PAGE_READ; return pte; }
+extern inline pte_t pte_mkclean(pte_t pte)      { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
+extern inline pte_t pte_mkold(pte_t pte)        { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
+extern inline pte_t pte_wrprotect(pte_t pte)    { pte_val(pte) &= ~_PAGE_WRITE; return pte; }
+extern inline pte_t pte_mkread(pte_t pte)       { pte_val(pte) |= _PAGE_READ; return pte; }
+extern inline pte_t pte_mkdirty(pte_t pte)      { pte_val(pte) |= _PAGE_DIRTY; return pte; }
+extern inline pte_t pte_mkyoung(pte_t pte)      { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
+extern inline pte_t pte_mkwrite(pte_t pte)      { pte_val(pte) |= _PAGE_WRITE; 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)+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 << PAGE_SHIFT) | pgprot_val(pgprot);
+        return pte;
+}
+
+/* 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; })
+
+extern 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) >> PAGE_SHIFT)
+
+#define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
+
+#define pmd_page_kernel(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 PT_NLEVELS == 3
+#define pmd_offset(dir,address) \
+((pmd_t *) pgd_page(*(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_kernel(*(pmd)) + pte_index(address))
+#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
+#define pte_offset_map_nested(pmd, address) pte_offset_kernel(pmd, address)
+#define pte_unmap(pte) do { } while (0)
+#define pte_unmap_nested(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
+
+struct vm_area_struct; /* forward declaration (include/linux/mm.h) */
+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)
+{
+#ifdef CONFIG_SMP
+        if (!pte_young(*ptep))
+                return 0;
+        return test_and_clear_bit(xlate_pabit(_PAGE_ACCESSED_BIT), &pte_val(*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 int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
+{
+#ifdef CONFIG_SMP
+        if (!pte_dirty(*ptep))
+                return 0;
+        return test_and_clear_bit(xlate_pabit(_PAGE_DIRTY_BIT), &pte_val(*ptep));
+#else
+        pte_t pte = *ptep;
+        if (!pte_dirty(pte))
+                return 0;
+        set_pte_at(vma->vm_mm, addr, ptep, pte_mkclean(pte));
+        return 1;
+#endif
+}
+
+extern spinlock_t pa_dbit_lock;
+
+static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+        pte_t old_pte;
+        pte_t pte;
+
+        spin_lock(&pa_dbit_lock);
+        pte = old_pte = *ptep;
+        pte_val(pte) &= ~_PAGE_PRESENT;
+        pte_val(pte) |= _PAGE_FLUSH;
+        set_pte_at(mm,addr,ptep,pte);
+        spin_unlock(&pa_dbit_lock);
+
+        return old_pte;
+}
+
+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
+}
+
+#define pte_same(A,B)   (pte_val(A) == pte_val(B))
+
+#endif /* !__ASSEMBLY__ */
+
+#define io_remap_page_range(vma, vaddr, paddr, size, prot)              \
+                remap_pfn_range(vma, vaddr, (paddr) >> PAGE_SHIFT, size, prot)
+
+#define io_remap_pfn_range(vma, vaddr, pfn, size, prot)         \
+                remap_pfn_range(vma, vaddr, pfn, size, prot)
+
+#define MK_IOSPACE_PFN(space, pfn)      (pfn)
+#define GET_IOSPACE(pfn)                0
+#define GET_PFN(pfn)                    (pfn)
+
+/* We provide our own get_unmapped_area to provide cache coherency */
+
+#define HAVE_ARCH_UNMAPPED_AREA
+
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
+#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 */