1 files changed, 1093 insertions, 0 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
new file mode 100644
index 000000000000..0bdb704ae051
--- /dev/null
+++ b/arch/s390/include/asm/pgtable.h
@@ -0,0 +1,1093 @@
+/*
+ *  include/asm-s390/pgtable.h
+ *
+ *  S390 version
+ *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Hartmut Penner (hp@de.ibm.com)
+ *               Ulrich Weigand (weigand@de.ibm.com)
+ *               Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ *  Derived from "include/asm-i386/pgtable.h"
+ */
+
+#ifndef _ASM_S390_PGTABLE_H
+#define _ASM_S390_PGTABLE_H
+
+/*
+ * The Linux memory management assumes a three-level page table setup. For
+ * s390 31 bit we "fold" the mid level into the top-level page table, so
+ * that we physically have the same two-level page table as the s390 mmu
+ * expects in 31 bit mode. For s390 64 bit we use three of the five levels
+ * the hardware provides (region first and region second tables are not
+ * used).
+ *
+ * The "pgd_xxx()" functions 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)
+ *
+ * This file contains the functions and defines necessary to modify and use
+ * the S390 page table tree.
+ */
+#ifndef __ASSEMBLY__
+#include <linux/sched.h>
+#include <linux/mm_types.h>
+#include <asm/bitops.h>
+#include <asm/bug.h>
+#include <asm/processor.h>
+
+extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
+extern void paging_init(void);
+extern void vmem_map_init(void);
+
+/*
+ * The S390 doesn't have any external MMU info: the kernel page
+ * tables contain all the necessary information.
+ */
+#define update_mmu_cache(vma, address, pte)     do { } while (0)
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+extern char empty_zero_page[PAGE_SIZE];
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * PMD_SHIFT determines the size of the area a second-level page
+ * table can map
+ * PGDIR_SHIFT determines what a third-level page table entry can map
+ */
+#ifndef __s390x__
+# define PMD_SHIFT      20
+# define PUD_SHIFT      20
+# define PGDIR_SHIFT    20
+#else /* __s390x__ */
+# define PMD_SHIFT      20
+# define PUD_SHIFT      31
+# define PGDIR_SHIFT    42
+#endif /* __s390x__ */
+
+#define PMD_SIZE        (1UL << PMD_SHIFT)
+#define PMD_MASK        (~(PMD_SIZE-1))
+#define PUD_SIZE        (1UL << PUD_SHIFT)
+#define PUD_MASK        (~(PUD_SIZE-1))
+#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK      (~(PGDIR_SIZE-1))
+
+/*
+ * entries per page directory level: the S390 is two-level, so
+ * we don't really have any PMD directory physically.
+ * for S390 segment-table entries are combined to one PGD
+ * that leads to 1024 pte per pgd
+ */
+#define PTRS_PER_PTE    256
+#ifndef __s390x__
+#define PTRS_PER_PMD    1
+#define PTRS_PER_PUD    1
+#else /* __s390x__ */
+#define PTRS_PER_PMD    2048
+#define PTRS_PER_PUD    2048
+#endif /* __s390x__ */
+#define PTRS_PER_PGD    2048
+
+#define FIRST_USER_ADDRESS  0
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
+#define pmd_ERROR(e) \
+        printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
+#define pud_ERROR(e) \
+        printk("%s:%d: bad pud %p.\n", __FILE__, __LINE__, (void *) pud_val(e))
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))
+
+#ifndef __ASSEMBLY__
+/*
+ * The vmalloc area will always be on the topmost area of the kernel
+ * mapping. We reserve 96MB (31bit) / 1GB (64bit) for vmalloc,
+ * which should be enough for any sane case.
+ * By putting vmalloc at the top, we maximise the gap between physical
+ * memory and vmalloc to catch misplaced memory accesses. As a side
+ * effect, this also makes sure that 64 bit module code cannot be used
+ * as system call address.
+ */
+#ifndef __s390x__
+#define VMALLOC_START   0x78000000UL
+#define VMALLOC_END     0x7e000000UL
+#define VMEM_MAP_END    0x80000000UL
+#else /* __s390x__ */
+#define VMALLOC_START   0x3e000000000UL
+#define VMALLOC_END     0x3e040000000UL
+#define VMEM_MAP_END    0x40000000000UL
+#endif /* __s390x__ */
+
+/*
+ * VMEM_MAX_PHYS is the highest physical address that can be added to the 1:1
+ * mapping. This needs to be calculated at compile time since the size of the
+ * VMEM_MAP is static but the size of struct page can change.
+ */
+#define VMEM_MAX_PAGES  ((VMEM_MAP_END - VMALLOC_END) / sizeof(struct page))
+#define VMEM_MAX_PFN    min(VMALLOC_START >> PAGE_SHIFT, VMEM_MAX_PAGES)
+#define VMEM_MAX_PHYS   ((VMEM_MAX_PFN << PAGE_SHIFT) & ~((16 << 20) - 1))
+#define vmemmap         ((struct page *) VMALLOC_END)
+
+/*
+ * A 31 bit pagetable entry of S390 has following format:
+ *  |   PFRA          |    |  OS  |
+ * 0                   0IP0
+ * 00000000001111111111222222222233
+ * 01234567890123456789012345678901
+ *
+ * I Page-Invalid Bit:    Page is not available for address-translation
+ * P Page-Protection Bit: Store access not possible for page
+ *
+ * A 31 bit segmenttable entry of S390 has following format:
+ *  |   P-table origin      |  |PTL
+ * 0                         IC
+ * 00000000001111111111222222222233
+ * 01234567890123456789012345678901
+ *
+ * I Segment-Invalid Bit:    Segment is not available for address-translation
+ * C Common-Segment Bit:     Segment is not private (PoP 3-30)
+ * PTL Page-Table-Length:    Page-table length (PTL+1*16 entries -> up to 256)
+ *
+ * The 31 bit segmenttable origin of S390 has following format:
+ *
+ *  |S-table origin   |     | STL |
+ * X                   **GPS
+ * 00000000001111111111222222222233
+ * 01234567890123456789012345678901
+ *
+ * X Space-Switch event:
+ * G Segment-Invalid Bit:     *
+ * P Private-Space Bit:       Segment is not private (PoP 3-30)
+ * S Storage-Alteration:
+ * STL Segment-Table-Length:  Segment-table length (STL+1*16 entries -> up to 2048)
+ *
+ * A 64 bit pagetable entry of S390 has following format:
+ * |                     PFRA                         |0IP0|  OS  |
+ * 0000000000111111111122222222223333333333444444444455555555556666
+ * 0123456789012345678901234567890123456789012345678901234567890123
+ *
+ * I Page-Invalid Bit:    Page is not available for address-translation
+ * P Page-Protection Bit: Store access not possible for page
+ *
+ * A 64 bit segmenttable entry of S390 has following format:
+ * |        P-table origin                              |      TT
+ * 0000000000111111111122222222223333333333444444444455555555556666
+ * 0123456789012345678901234567890123456789012345678901234567890123
+ *
+ * I Segment-Invalid Bit:    Segment is not available for address-translation
+ * C Common-Segment Bit:     Segment is not private (PoP 3-30)
+ * P Page-Protection Bit: Store access not possible for page
+ * TT Type 00
+ *
+ * A 64 bit region table entry of S390 has following format:
+ * |        S-table origin                             |   TF  TTTL
+ * 0000000000111111111122222222223333333333444444444455555555556666
+ * 0123456789012345678901234567890123456789012345678901234567890123
+ *
+ * I Segment-Invalid Bit:    Segment is not available for address-translation
+ * TT Type 01
+ * TF
+ * TL Table length
+ *
+ * The 64 bit regiontable origin of S390 has following format:
+ * |      region table origon                          |       DTTL
+ * 0000000000111111111122222222223333333333444444444455555555556666
+ * 0123456789012345678901234567890123456789012345678901234567890123
+ *
+ * X Space-Switch event:
+ * G Segment-Invalid Bit:  
+ * P Private-Space Bit:    
+ * S Storage-Alteration:
+ * R Real space
+ * TL Table-Length:
+ *
+ * A storage key has the following format:
+ * | ACC |F|R|C|0|
+ *  0   3 4 5 6 7
+ * ACC: access key
+ * F  : fetch protection bit
+ * R  : referenced bit
+ * C  : changed bit
+ */
+
+/* Hardware bits in the page table entry */
+#define _PAGE_RO        0x200           /* HW read-only bit  */
+#define _PAGE_INVALID   0x400           /* HW invalid bit    */
+
+/* Software bits in the page table entry */
+#define _PAGE_SWT       0x001           /* SW pte type bit t */
+#define _PAGE_SWX       0x002           /* SW pte type bit x */
+#define _PAGE_SPECIAL   0x004           /* SW associated with special page */
+#define __HAVE_ARCH_PTE_SPECIAL
+
+/* Set of bits not changed in pte_modify */
+#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_SPECIAL)
+
+/* Six different types of pages. */
+#define _PAGE_TYPE_EMPTY        0x400
+#define _PAGE_TYPE_NONE         0x401
+#define _PAGE_TYPE_SWAP         0x403
+#define _PAGE_TYPE_FILE         0x601   /* bit 0x002 is used for offset !! */
+#define _PAGE_TYPE_RO           0x200
+#define _PAGE_TYPE_RW           0x000
+#define _PAGE_TYPE_EX_RO        0x202
+#define _PAGE_TYPE_EX_RW        0x002
+
+/*
+ * Only four types for huge pages, using the invalid bit and protection bit
+ * of a segment table entry.
+ */
+#define _HPAGE_TYPE_EMPTY       0x020   /* _SEGMENT_ENTRY_INV */
+#define _HPAGE_TYPE_NONE        0x220
+#define _HPAGE_TYPE_RO          0x200   /* _SEGMENT_ENTRY_RO  */
+#define _HPAGE_TYPE_RW          0x000
+
+/*
+ * PTE type bits are rather complicated. handle_pte_fault uses pte_present,
+ * pte_none and pte_file to find out the pte type WITHOUT holding the page
+ * table lock. ptep_clear_flush on the other hand uses ptep_clear_flush to
+ * invalidate a given pte. ipte sets the hw invalid bit and clears all tlbs
+ * for the page. The page table entry is set to _PAGE_TYPE_EMPTY afterwards.
+ * This change is done while holding the lock, but the intermediate step
+ * of a previously valid pte with the hw invalid bit set can be observed by
+ * handle_pte_fault. That makes it necessary that all valid pte types with
+ * the hw invalid bit set must be distinguishable from the four pte types
+ * empty, none, swap and file.
+ *
+ *                      irxt  ipte  irxt
+ * _PAGE_TYPE_EMPTY     1000   ->   1000
+ * _PAGE_TYPE_NONE      1001   ->   1001
+ * _PAGE_TYPE_SWAP      1011   ->   1011
+ * _PAGE_TYPE_FILE      11?1   ->   11?1
+ * _PAGE_TYPE_RO        0100   ->   1100
+ * _PAGE_TYPE_RW        0000   ->   1000
+ * _PAGE_TYPE_EX_RO     0110   ->   1110
+ * _PAGE_TYPE_EX_RW     0010   ->   1010
+ *
+ * pte_none is true for bits combinations 1000, 1010, 1100, 1110
+ * pte_present is true for bits combinations 0000, 0010, 0100, 0110, 1001
+ * pte_file is true for bits combinations 1101, 1111
+ * swap pte is 1011 and 0001, 0011, 0101, 0111 are invalid.
+ */
+
+/* Page status table bits for virtualization */
+#define RCP_PCL_BIT     55
+#define RCP_HR_BIT      54
+#define RCP_HC_BIT      53
+#define RCP_GR_BIT      50
+#define RCP_GC_BIT      49
+
+#ifndef __s390x__
+
+/* Bits in the segment table address-space-control-element */
+#define _ASCE_SPACE_SWITCH      0x80000000UL    /* space switch event       */
+#define _ASCE_ORIGIN_MASK       0x7ffff000UL    /* segment table origin     */
+#define _ASCE_PRIVATE_SPACE     0x100   /* private space control            */
+#define _ASCE_ALT_EVENT         0x80    /* storage alteration event control */
+#define _ASCE_TABLE_LENGTH      0x7f    /* 128 x 64 entries = 8k            */
+
+/* Bits in the segment table entry */
+#define _SEGMENT_ENTRY_ORIGIN   0x7fffffc0UL    /* page table origin        */
+#define _SEGMENT_ENTRY_INV      0x20    /* invalid segment table entry      */
+#define _SEGMENT_ENTRY_COMMON   0x10    /* common segment bit               */
+#define _SEGMENT_ENTRY_PTL      0x0f    /* page table length                */
+
+#define _SEGMENT_ENTRY          (_SEGMENT_ENTRY_PTL)
+#define _SEGMENT_ENTRY_EMPTY    (_SEGMENT_ENTRY_INV)
+
+#else /* __s390x__ */
+
+/* Bits in the segment/region table address-space-control-element */
+#define _ASCE_ORIGIN            ~0xfffUL/* segment table origin             */
+#define _ASCE_PRIVATE_SPACE     0x100   /* private space control            */
+#define _ASCE_ALT_EVENT         0x80    /* storage alteration event control */
+#define _ASCE_SPACE_SWITCH      0x40    /* space switch event               */
+#define _ASCE_REAL_SPACE        0x20    /* real space control               */
+#define _ASCE_TYPE_MASK         0x0c    /* asce table type mask             */
+#define _ASCE_TYPE_REGION1      0x0c    /* region first table type          */
+#define _ASCE_TYPE_REGION2      0x08    /* region second table type         */
+#define _ASCE_TYPE_REGION3      0x04    /* region third table type          */
+#define _ASCE_TYPE_SEGMENT      0x00    /* segment table type               */
+#define _ASCE_TABLE_LENGTH      0x03    /* region table length              */
+
+/* Bits in the region table entry */
+#define _REGION_ENTRY_ORIGIN    ~0xfffUL/* region/segment table origin      */
+#define _REGION_ENTRY_INV       0x20    /* invalid region table entry       */
+#define _REGION_ENTRY_TYPE_MASK 0x0c    /* region/segment table type mask   */
+#define _REGION_ENTRY_TYPE_R1   0x0c    /* region first table type          */
+#define _REGION_ENTRY_TYPE_R2   0x08    /* region second table type         */
+#define _REGION_ENTRY_TYPE_R3   0x04    /* region third table type          */
+#define _REGION_ENTRY_LENGTH    0x03    /* region third length              */
+
+#define _REGION1_ENTRY          (_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_LENGTH)
+#define _REGION1_ENTRY_EMPTY    (_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INV)
+#define _REGION2_ENTRY          (_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_LENGTH)
+#define _REGION2_ENTRY_EMPTY    (_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INV)
+#define _REGION3_ENTRY          (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH)
+#define _REGION3_ENTRY_EMPTY    (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INV)
+
+/* Bits in the segment table entry */
+#define _SEGMENT_ENTRY_ORIGIN   ~0x7ffUL/* segment table origin             */
+#define _SEGMENT_ENTRY_RO       0x200   /* page protection bit              */
+#define _SEGMENT_ENTRY_INV      0x20    /* invalid segment table entry      */
+
+#define _SEGMENT_ENTRY          (0)
+#define _SEGMENT_ENTRY_EMPTY    (_SEGMENT_ENTRY_INV)
+
+#define _SEGMENT_ENTRY_LARGE    0x400   /* STE-format control, large page   */
+#define _SEGMENT_ENTRY_CO       0x100   /* change-recording override   */
+
+#endif /* __s390x__ */
+
+/*
+ * A user page table pointer has the space-switch-event bit, the
+ * private-space-control bit and the storage-alteration-event-control
+ * bit set. A kernel page table pointer doesn't need them.
+ */
+#define _ASCE_USER_BITS         (_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \
+                                 _ASCE_ALT_EVENT)
+
+/* Bits int the storage key */
+#define _PAGE_CHANGED    0x02          /* HW changed bit                   */
+#define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
+
+/*
+ * Page protection definitions.
+ */
+#define PAGE_NONE       __pgprot(_PAGE_TYPE_NONE)
+#define PAGE_RO         __pgprot(_PAGE_TYPE_RO)
+#define PAGE_RW         __pgprot(_PAGE_TYPE_RW)
+#define PAGE_EX_RO      __pgprot(_PAGE_TYPE_EX_RO)
+#define PAGE_EX_RW      __pgprot(_PAGE_TYPE_EX_RW)
+
+#define PAGE_KERNEL     PAGE_RW
+#define PAGE_COPY       PAGE_RO
+
+/*
+ * Dependent on the EXEC_PROTECT option s390 can do execute protection.
+ * Write permission always implies read permission. In theory with a
+ * primary/secondary page table execute only can be implemented but
+ * it would cost an additional bit in the pte to distinguish all the
+ * different pte types. To avoid that execute permission currently
+ * implies read permission as well.
+ */
+         /*xwr*/
+#define __P000  PAGE_NONE
+#define __P001  PAGE_RO
+#define __P010  PAGE_RO
+#define __P011  PAGE_RO
+#define __P100  PAGE_EX_RO
+#define __P101  PAGE_EX_RO
+#define __P110  PAGE_EX_RO
+#define __P111  PAGE_EX_RO
+
+#define __S000  PAGE_NONE
+#define __S001  PAGE_RO
+#define __S010  PAGE_RW
+#define __S011  PAGE_RW
+#define __S100  PAGE_EX_RO
+#define __S101  PAGE_EX_RO
+#define __S110  PAGE_EX_RW
+#define __S111  PAGE_EX_RW
+
+#ifndef __s390x__
+# define PxD_SHADOW_SHIFT       1
+#else /* __s390x__ */
+# define PxD_SHADOW_SHIFT       2
+#endif /* __s390x__ */
+
+static inline void *get_shadow_table(void *table)
+{
+        unsigned long addr, offset;
+        struct page *page;
+
+        addr = (unsigned long) table;
+        offset = addr & ((PAGE_SIZE << PxD_SHADOW_SHIFT) - 1);
+        page = virt_to_page((void *)(addr ^ offset));
+        return (void *)(addr_t)(page->index ? (page->index | offset) : 0UL);
+}
+
+/*
+ * Certain architectures need to do special things when PTEs
+ * within a page table are directly modified.  Thus, the following
+ * hook is made available.
+ */
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+                              pte_t *ptep, pte_t entry)
+{
+        *ptep = entry;
+        if (mm->context.noexec) {
+                if (!(pte_val(entry) & _PAGE_INVALID) &&
+                    (pte_val(entry) & _PAGE_SWX))
+                        pte_val(entry) |= _PAGE_RO;
+                else
+                        pte_val(entry) = _PAGE_TYPE_EMPTY;
+                ptep[PTRS_PER_PTE] = entry;
+        }
+}
+
+/*
+ * pgd/pmd/pte query functions
+ */
+#ifndef __s390x__
+
+static inline int pgd_present(pgd_t pgd) { return 1; }
+static inline int pgd_none(pgd_t pgd)    { return 0; }
+static inline int pgd_bad(pgd_t pgd)     { return 0; }
+
+static inline int pud_present(pud_t pud) { return 1; }
+static inline int pud_none(pud_t pud)    { return 0; }
+static inline int pud_bad(pud_t pud)     { return 0; }
+
+#else /* __s390x__ */
+
+static inline int pgd_present(pgd_t pgd)
+{
+        if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
+                return 1;
+        return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL;
+}
+
+static inline int pgd_none(pgd_t pgd)
+{
+        if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2)
+                return 0;
+        return (pgd_val(pgd) & _REGION_ENTRY_INV) != 0UL;
+}
+
+static inline int pgd_bad(pgd_t pgd)
+{
+        /*
+         * With dynamic page table levels the pgd can be a region table
+         * entry or a segment table entry. Check for the bit that are
+         * invalid for either table entry.
+         */
+        unsigned long mask =
+                ~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV &
+                ~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
+        return (pgd_val(pgd) & mask) != 0;
+}
+
+static inline int pud_present(pud_t pud)
+{
+        if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
+                return 1;
+        return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL;
+}
+
+static inline int pud_none(pud_t pud)
+{
+        if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3)
+                return 0;
+        return (pud_val(pud) & _REGION_ENTRY_INV) != 0UL;
+}
+
+static inline int pud_bad(pud_t pud)
+{
+        /*
+         * With dynamic page table levels the pud can be a region table
+         * entry or a segment table entry. Check for the bit that are
+         * invalid for either table entry.
+         */
+        unsigned long mask =
+                ~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV &
+                ~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH;
+        return (pud_val(pud) & mask) != 0;
+}
+
+#endif /* __s390x__ */
+
+static inline int pmd_present(pmd_t pmd)
+{
+        return (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN) != 0UL;
+}
+
+static inline int pmd_none(pmd_t pmd)
+{
+        return (pmd_val(pmd) & _SEGMENT_ENTRY_INV) != 0UL;
+}
+
+static inline int pmd_bad(pmd_t pmd)
+{
+        unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV;
+        return (pmd_val(pmd) & mask) != _SEGMENT_ENTRY;
+}
+
+static inline int pte_none(pte_t pte)
+{
+        return (pte_val(pte) & _PAGE_INVALID) && !(pte_val(pte) & _PAGE_SWT);
+}
+
+static inline int pte_present(pte_t pte)
+{
+        unsigned long mask = _PAGE_RO | _PAGE_INVALID | _PAGE_SWT | _PAGE_SWX;
+        return (pte_val(pte) & mask) == _PAGE_TYPE_NONE ||
+                (!(pte_val(pte) & _PAGE_INVALID) &&
+                 !(pte_val(pte) & _PAGE_SWT));
+}
+
+static inline int pte_file(pte_t pte)
+{
+        unsigned long mask = _PAGE_RO | _PAGE_INVALID | _PAGE_SWT;
+        return (pte_val(pte) & mask) == _PAGE_TYPE_FILE;
+}
+
+static inline int pte_special(pte_t pte)
+{
+        return (pte_val(pte) & _PAGE_SPECIAL);
+}
+
+#define __HAVE_ARCH_PTE_SAME
+#define pte_same(a,b)  (pte_val(a) == pte_val(b))
+
+static inline void rcp_lock(pte_t *ptep)
+{
+#ifdef CONFIG_PGSTE
+        unsigned long *pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
+        preempt_disable();
+        while (test_and_set_bit(RCP_PCL_BIT, pgste))
+                ;
+#endif
+}
+
+static inline void rcp_unlock(pte_t *ptep)
+{
+#ifdef CONFIG_PGSTE
+        unsigned long *pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
+        clear_bit(RCP_PCL_BIT, pgste);
+        preempt_enable();
+#endif
+}
+
+/* forward declaration for SetPageUptodate in page-flags.h*/
+static inline void page_clear_dirty(struct page *page);
+#include <linux/page-flags.h>
+
+static inline void ptep_rcp_copy(pte_t *ptep)
+{
+#ifdef CONFIG_PGSTE
+        struct page *page = virt_to_page(pte_val(*ptep));
+        unsigned int skey;
+        unsigned long *pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
+
+        skey = page_get_storage_key(page_to_phys(page));
+        if (skey & _PAGE_CHANGED)
+                set_bit_simple(RCP_GC_BIT, pgste);
+        if (skey & _PAGE_REFERENCED)
+                set_bit_simple(RCP_GR_BIT, pgste);
+        if (test_and_clear_bit_simple(RCP_HC_BIT, pgste))
+                SetPageDirty(page);
+        if (test_and_clear_bit_simple(RCP_HR_BIT, pgste))
+                SetPageReferenced(page);
+#endif
+}
+
+/*
+ * query functions pte_write/pte_dirty/pte_young only work if
+ * pte_present() is true. Undefined behaviour if not..
+ */
+static inline int pte_write(pte_t pte)
+{
+        return (pte_val(pte) & _PAGE_RO) == 0;
+}
+
+static inline int pte_dirty(pte_t pte)
+{
+        /* A pte is neither clean nor dirty on s/390. The dirty bit
+         * is in the storage key. See page_test_and_clear_dirty for
+         * details.
+         */
+        return 0;
+}
+
+static inline int pte_young(pte_t pte)
+{
+        /* A pte is neither young nor old on s/390. The young bit
+         * is in the storage key. See page_test_and_clear_young for
+         * details.
+         */
+        return 0;
+}
+
+/*
+ * pgd/pmd/pte modification functions
+ */
+
+#ifndef __s390x__
+
+#define pgd_clear(pgd)          do { } while (0)
+#define pud_clear(pud)          do { } while (0)
+
+#else /* __s390x__ */
+
+static inline void pgd_clear_kernel(pgd_t * pgd)
+{
+        if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
+                pgd_val(*pgd) = _REGION2_ENTRY_EMPTY;
+}
+
+static inline void pgd_clear(pgd_t * pgd)
+{
+        pgd_t *shadow = get_shadow_table(pgd);
+
+        pgd_clear_kernel(pgd);
+        if (shadow)
+                pgd_clear_kernel(shadow);
+}
+
+static inline void pud_clear_kernel(pud_t *pud)
+{
+        if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
+                pud_val(*pud) = _REGION3_ENTRY_EMPTY;
+}
+
+static inline void pud_clear(pud_t *pud)
+{
+        pud_t *shadow = get_shadow_table(pud);
+
+        pud_clear_kernel(pud);
+        if (shadow)
+                pud_clear_kernel(shadow);
+}
+
+#endif /* __s390x__ */
+
+static inline void pmd_clear_kernel(pmd_t * pmdp)
+{
+        pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
+}
+
+static inline void pmd_clear(pmd_t *pmd)
+{
+        pmd_t *shadow = get_shadow_table(pmd);
+
+        pmd_clear_kernel(pmd);
+        if (shadow)
+                pmd_clear_kernel(shadow);
+}
+
+static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+        if (mm->context.pgstes)
+                ptep_rcp_copy(ptep);
+        pte_val(*ptep) = _PAGE_TYPE_EMPTY;
+        if (mm->context.noexec)
+                pte_val(ptep[PTRS_PER_PTE]) = _PAGE_TYPE_EMPTY;
+}
+
+/*
+ * The following pte modification functions only work if
+ * pte_present() is true. Undefined behaviour if not..
+ */
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+        pte_val(pte) &= _PAGE_CHG_MASK;
+        pte_val(pte) |= pgprot_val(newprot);
+        return pte;
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+        /* Do not clobber _PAGE_TYPE_NONE pages!  */
+        if (!(pte_val(pte) & _PAGE_INVALID))
+                pte_val(pte) |= _PAGE_RO;
+        return pte;
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+        pte_val(pte) &= ~_PAGE_RO;
+        return pte;
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+        /* The only user of pte_mkclean is the fork() code.
+           We must *not* clear the *physical* page dirty bit
+           just because fork() wants to clear the dirty bit in
+           *one* of the page's mappings.  So we just do nothing. */
+        return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+        /* We do not explicitly set the dirty bit because the
+         * sske instruction is slow. It is faster to let the
+         * next instruction set the dirty bit.
+         */
+        return pte;
+}
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+        /* S/390 doesn't keep its dirty/referenced bit in the pte.
+         * There is no point in clearing the real referenced bit.
+         */
+        return pte;
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+        /* S/390 doesn't keep its dirty/referenced bit in the pte.
+         * There is no point in setting the real referenced bit.
+         */
+        return pte;
+}
+
+static inline pte_t pte_mkspecial(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_SPECIAL;
+        return pte;
+}
+
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
+                                            unsigned long addr, pte_t *ptep)
+{
+#ifdef CONFIG_PGSTE
+        unsigned long physpage;
+        int young;
+        unsigned long *pgste;
+
+        if (!vma->vm_mm->context.pgstes)
+                return 0;
+        physpage = pte_val(*ptep) & PAGE_MASK;
+        pgste = (unsigned long *) (ptep + PTRS_PER_PTE);
+
+        young = ((page_get_storage_key(physpage) & _PAGE_REFERENCED) != 0);
+        rcp_lock(ptep);
+        if (young)
+                set_bit_simple(RCP_GR_BIT, pgste);
+        young |= test_and_clear_bit_simple(RCP_HR_BIT, pgste);
+        rcp_unlock(ptep);
+        return young;
+#endif
+        return 0;
+}
+
+#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
+static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
+                                         unsigned long address, pte_t *ptep)
+{
+        /* No need to flush TLB
+         * On s390 reference bits are in storage key and never in TLB
+         * With virtualization we handle the reference bit, without we
+         * we can simply return */
+#ifdef CONFIG_PGSTE
+        return ptep_test_and_clear_young(vma, address, ptep);
+#endif
+        return 0;
+}
+
+static inline void __ptep_ipte(unsigned long address, pte_t *ptep)
+{
+        if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+#ifndef __s390x__
+                /* pto must point to the start of the segment table */
+                pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00);
+#else
+                /* ipte in zarch mode can do the math */
+                pte_t *pto = ptep;
+#endif
+                asm volatile(
+                        "       ipte    %2,%3"
+                        : "=m" (*ptep) : "m" (*ptep),
+                          "a" (pto), "a" (address));
+        }
+}
+
+static inline void ptep_invalidate(struct mm_struct *mm,
+                                   unsigned long address, pte_t *ptep)
+{
+        if (mm->context.pgstes) {
+                rcp_lock(ptep);
+                __ptep_ipte(address, ptep);
+                ptep_rcp_copy(ptep);
+                pte_val(*ptep) = _PAGE_TYPE_EMPTY;
+                rcp_unlock(ptep);
+                return;
+        }
+        __ptep_ipte(address, ptep);
+        pte_val(*ptep) = _PAGE_TYPE_EMPTY;
+        if (mm->context.noexec) {
+                __ptep_ipte(address, ptep + PTRS_PER_PTE);
+                pte_val(*(ptep + PTRS_PER_PTE)) = _PAGE_TYPE_EMPTY;
+        }
+}
+
+/*
+ * This is hard to understand. ptep_get_and_clear and ptep_clear_flush
+ * both clear the TLB for the unmapped pte. The reason is that
+ * ptep_get_and_clear is used in common code (e.g. change_pte_range)
+ * to modify an active pte. The sequence is
+ *   1) ptep_get_and_clear
+ *   2) set_pte_at
+ *   3) flush_tlb_range
+ * On s390 the tlb needs to get flushed with the modification of the pte
+ * if the pte is active. The only way how this can be implemented is to
+ * have ptep_get_and_clear do the tlb flush. In exchange flush_tlb_range
+ * is a nop.
+ */
+#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
+#define ptep_get_and_clear(__mm, __address, __ptep)                     \
+({                                                                      \
+        pte_t __pte = *(__ptep);                                        \
+        if (atomic_read(&(__mm)->mm_users) > 1 ||                       \
+            (__mm) != current->active_mm)                               \
+                ptep_invalidate(__mm, __address, __ptep);               \
+        else                                                            \
+                pte_clear((__mm), (__address), (__ptep));               \
+        __pte;                                                          \
+})
+
+#define __HAVE_ARCH_PTEP_CLEAR_FLUSH
+static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
+                                     unsigned long address, pte_t *ptep)
+{
+        pte_t pte = *ptep;
+        ptep_invalidate(vma->vm_mm, address, ptep);
+        return pte;
+}
+
+/*
+ * The batched pte unmap code uses ptep_get_and_clear_full to clear the
+ * ptes. Here an optimization is possible. tlb_gather_mmu flushes all
+ * tlbs of an mm if it can guarantee that the ptes of the mm_struct
+ * cannot be accessed while the batched unmap is running. In this case
+ * full==1 and a simple pte_clear is enough. See tlb.h.
+ */
+#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
+static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
+                                            unsigned long addr,
+                                            pte_t *ptep, int full)
+{
+        pte_t pte = *ptep;
+
+        if (full)
+                pte_clear(mm, addr, ptep);
+        else
+                ptep_invalidate(mm, addr, ptep);
+        return pte;
+}
+
+#define __HAVE_ARCH_PTEP_SET_WRPROTECT
+#define ptep_set_wrprotect(__mm, __addr, __ptep)                        \
+({                                                                      \
+        pte_t __pte = *(__ptep);                                        \
+        if (pte_write(__pte)) {                                         \
+                if (atomic_read(&(__mm)->mm_users) > 1 ||               \
+                    (__mm) != current->active_mm)                       \
+                        ptep_invalidate(__mm, __addr, __ptep);          \
+                set_pte_at(__mm, __addr, __ptep, pte_wrprotect(__pte)); \
+        }                                                               \
+})
+
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+#define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty)  \
+({                                                                      \
+        int __changed = !pte_same(*(__ptep), __entry);                  \
+        if (__changed) {                                                \
+                ptep_invalidate((__vma)->vm_mm, __addr, __ptep);        \
+                set_pte_at((__vma)->vm_mm, __addr, __ptep, __entry);    \
+        }                                                               \
+        __changed;                                                      \
+})
+
+/*
+ * Test and clear dirty bit in storage key.
+ * We can't clear the changed bit atomically. This is a potential
+ * race against modification of the referenced bit. This function
+ * should therefore only be called if it is not mapped in any
+ * address space.
+ */
+#define __HAVE_ARCH_PAGE_TEST_DIRTY
+static inline int page_test_dirty(struct page *page)
+{
+        return (page_get_storage_key(page_to_phys(page)) & _PAGE_CHANGED) != 0;
+}
+
+#define __HAVE_ARCH_PAGE_CLEAR_DIRTY
+static inline void page_clear_dirty(struct page *page)
+{
+        page_set_storage_key(page_to_phys(page), PAGE_DEFAULT_KEY);
+}
+
+/*
+ * Test and clear referenced bit in storage key.
+ */
+#define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
+static inline int page_test_and_clear_young(struct page *page)
+{
+        unsigned long physpage = page_to_phys(page);
+        int ccode;
+
+        asm volatile(
+                "       rrbe    0,%1\n"
+                "       ipm     %0\n"
+                "       srl     %0,28\n"
+                : "=d" (ccode) : "a" (physpage) : "cc" );
+        return ccode & 2;
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
+{
+        pte_t __pte;
+        pte_val(__pte) = physpage + pgprot_val(pgprot);
+        return __pte;
+}
+
+static inline pte_t mk_pte(struct page *page, pgprot_t pgprot)
+{
+        unsigned long physpage = page_to_phys(page);
+
+        return mk_pte_phys(physpage, pgprot);
+}
+
+#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
+#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
+#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
+
+#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+
+#ifndef __s390x__
+
+#define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
+#define pud_deref(pmd) ({ BUG(); 0UL; })
+#define pgd_deref(pmd) ({ BUG(); 0UL; })
+
+#define pud_offset(pgd, address) ((pud_t *) pgd)
+#define pmd_offset(pud, address) ((pmd_t *) pud + pmd_index(address))
+
+#else /* __s390x__ */
+
+#define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
+#define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN)
+#define pgd_deref(pgd) (pgd_val(pgd) & _REGION_ENTRY_ORIGIN)
+
+static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
+{
+        pud_t *pud = (pud_t *) pgd;
+        if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
+                pud = (pud_t *) pgd_deref(*pgd);
+        return pud  + pud_index(address);
+}
+
+static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
+{
+        pmd_t *pmd = (pmd_t *) pud;
+        if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
+                pmd = (pmd_t *) pud_deref(*pud);
+        return pmd + pmd_index(address);
+}
+
+#endif /* __s390x__ */
+
+#define pfn_pte(pfn,pgprot) mk_pte_phys(__pa((pfn) << PAGE_SHIFT),(pgprot))
+#define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
+#define pte_page(x) pfn_to_page(pte_pfn(x))
+
+#define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
+
+/* Find an entry in the lowest level page table.. */
+#define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr))
+#define pte_offset_kernel(pmd, address) pte_offset(pmd,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)
+
+/*
+ * 31 bit swap entry format:
+ * A page-table entry has some bits we have to treat in a special way.
+ * Bits 0, 20 and bit 23 have to be zero, otherwise an specification
+ * exception will occur instead of a page translation exception. The
+ * specifiation exception has the bad habit not to store necessary
+ * information in the lowcore.
+ * Bit 21 and bit 22 are the page invalid bit and the page protection
+ * bit. We set both to indicate a swapped page.
+ * Bit 30 and 31 are used to distinguish the different page types. For
+ * a swapped page these bits need to be zero.
+ * This leaves the bits 1-19 and bits 24-29 to store type and offset.
+ * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19
+ * plus 24 for the offset.
+ * 0|     offset        |0110|o|type |00|
+ * 0 0000000001111111111 2222 2 22222 33
+ * 0 1234567890123456789 0123 4 56789 01
+ *
+ * 64 bit swap entry format:
+ * A page-table entry has some bits we have to treat in a special way.
+ * Bits 52 and bit 55 have to be zero, otherwise an specification
+ * exception will occur instead of a page translation exception. The
+ * specifiation exception has the bad habit not to store necessary
+ * information in the lowcore.
+ * Bit 53 and bit 54 are the page invalid bit and the page protection
+ * bit. We set both to indicate a swapped page.
+ * Bit 62 and 63 are used to distinguish the different page types. For
+ * a swapped page these bits need to be zero.
+ * This leaves the bits 0-51 and bits 56-61 to store type and offset.
+ * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51
+ * plus 56 for the offset.
+ * |                      offset                        |0110|o|type |00|
+ *  0000000000111111111122222222223333333333444444444455 5555 5 55566 66
+ *  0123456789012345678901234567890123456789012345678901 2345 6 78901 23
+ */
+#ifndef __s390x__
+#define __SWP_OFFSET_MASK (~0UL >> 12)
+#else
+#define __SWP_OFFSET_MASK (~0UL >> 11)
+#endif
+static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
+{
+        pte_t pte;
+        offset &= __SWP_OFFSET_MASK;
+        pte_val(pte) = _PAGE_TYPE_SWAP | ((type & 0x1f) << 2) |
+                ((offset & 1UL) << 7) | ((offset & ~1UL) << 11);
+        return pte;
+}
+
+#define __swp_type(entry)       (((entry).val >> 2) & 0x1f)
+#define __swp_offset(entry)     (((entry).val >> 11) | (((entry).val >> 7) & 1))
+#define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })
+
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
+
+#ifndef __s390x__
+# define PTE_FILE_MAX_BITS      26
+#else /* __s390x__ */
+# define PTE_FILE_MAX_BITS      59
+#endif /* __s390x__ */
+
+#define pte_to_pgoff(__pte) \
+        ((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f))
+
+#define pgoff_to_pte(__off) \
+        ((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \
+                   | _PAGE_TYPE_FILE })
+
+#endif /* !__ASSEMBLY__ */
+
+#define kern_addr_valid(addr)   (1)
+
+extern int vmem_add_mapping(unsigned long start, unsigned long size);
+extern int vmem_remove_mapping(unsigned long start, unsigned long size);
+extern int s390_enable_sie(void);
+
+/*
+ * No page table caches to initialise
+ */
+#define pgtable_cache_init()    do { } while (0)
+
+#include <asm-generic/pgtable.h>
+
+#endif /* _S390_PAGE_H */