[S390] Cleanup page table definitions.

- De-confuse the defines for the address-space-control-elements
  and the segment/region table entries.
- Create out of line functions for page table allocation / freeing.
- Simplify get_shadow_xxx functions.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

9 files changed, 305 insertions, 328 deletions

diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
index f95449b29fa5..66401930f83e 100644
--- a/arch/s390/mm/Makefile
+++ b/arch/s390/mm/Makefile
@@ -2,6 +2,6 @@
 # Makefile for the linux s390-specific parts of the memory manager.
 #
 
-obj-y    := init.o fault.o extmem.o mmap.o vmem.o
+obj-y    := init.o fault.o extmem.o mmap.o vmem.o pgtable.o
 obj-$(CONFIG_CMM) += cmm.o
 
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 3a25bbf2eb0a..90ec058aa7db 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -103,32 +103,28 @@ static void __init setup_ro_region(void)
  */
 void __init paging_init(void)
 {
-        pgd_t *pg_dir;
-        int i;
-        unsigned long pgdir_k;
         static const int ssm_mask = 0x04000000L;
         unsigned long max_zone_pfns[MAX_NR_ZONES];
+        unsigned long pgd_type;
 
-        pg_dir = swapper_pg_dir;
-        
+        init_mm.pgd = swapper_pg_dir;
+        S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
 #ifdef CONFIG_64BIT
-        pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
-        for (i = 0; i < PTRS_PER_PGD; i++)
-                pgd_clear_kernel(pg_dir + i);
+        S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
+        pgd_type = _REGION3_ENTRY_EMPTY;
 #else
-        pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
-        for (i = 0; i < PTRS_PER_PGD; i++)
-                pmd_clear_kernel((pmd_t *)(pg_dir + i));
+        S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
+        pgd_type = _SEGMENT_ENTRY_EMPTY;
 #endif
+        clear_table((unsigned long *) init_mm.pgd, pgd_type,
+                    sizeof(unsigned long)*2048);
         vmem_map_init();
         setup_ro_region();
 
-        S390_lowcore.kernel_asce = pgdir_k;
-
         /* enable virtual mapping in kernel mode */
-        __ctl_load(pgdir_k, 1, 1);
-        __ctl_load(pgdir_k, 7, 7);
-        __ctl_load(pgdir_k, 13, 13);
+        __ctl_load(S390_lowcore.kernel_asce, 1, 1);
+        __ctl_load(S390_lowcore.kernel_asce, 7, 7);
+        __ctl_load(S390_lowcore.kernel_asce, 13, 13);
         __raw_local_irq_ssm(ssm_mask);
 
         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
new file mode 100644
index 000000000000..e60e0ae13402
--- /dev/null
+++ b/arch/s390/mm/pgtable.c
@@ -0,0 +1,94 @@
+/*
+ *  arch/s390/mm/pgtable.c
+ *
+ *    Copyright IBM Corp. 2007
+ *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/smp.h>
+#include <linux/highmem.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/quicklist.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+#ifndef CONFIG_64BIT
+#define ALLOC_ORDER     1
+#else
+#define ALLOC_ORDER     2
+#endif
+
+unsigned long *crst_table_alloc(struct mm_struct *mm, int noexec)
+{
+        struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+
+        if (!page)
+                return NULL;
+        page->index = 0;
+        if (noexec) {
+                struct page *shadow = alloc_pages(GFP_KERNEL, ALLOC_ORDER);
+                if (!shadow) {
+                        __free_pages(page, ALLOC_ORDER);
+                        return NULL;
+                }
+                page->index = page_to_phys(shadow);
+        }
+        return (unsigned long *) page_to_phys(page);
+}
+
+void crst_table_free(unsigned long *table)
+{
+        unsigned long *shadow = get_shadow_table(table);
+
+        if (shadow)
+                free_pages((unsigned long) shadow, ALLOC_ORDER);
+        free_pages((unsigned long) table, ALLOC_ORDER);
+}
+
+/*
+ * page table entry allocation/free routines.
+ */
+unsigned long *page_table_alloc(int noexec)
+{
+        struct page *page = alloc_page(GFP_KERNEL);
+        unsigned long *table;
+
+        if (!page)
+                return NULL;
+        page->index = 0;
+        if (noexec) {
+                struct page *shadow = alloc_page(GFP_KERNEL);
+                if (!shadow) {
+                        __free_page(page);
+                        return NULL;
+                }
+                table = (unsigned long *) page_to_phys(shadow);
+                clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
+                page->index = (addr_t) table;
+        }
+        table = (unsigned long *) page_to_phys(page);
+        clear_table(table, _PAGE_TYPE_EMPTY, PAGE_SIZE);
+        return table;
+}
+
+void page_table_free(unsigned long *table)
+{
+        unsigned long *shadow = get_shadow_pte(table);
+
+        if (shadow)
+                free_page((unsigned long) shadow);
+        free_page((unsigned long) table);
+
+}
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index fd594d5fe142..1bd51d840484 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -75,29 +75,24 @@ static void __init_refok *vmem_alloc_pages(unsigned int order)
 
 static inline pmd_t *vmem_pmd_alloc(void)
 {
-        pmd_t *pmd;
-        int i;
+        pmd_t *pmd = NULL;
 
-        pmd = vmem_alloc_pages(PMD_ALLOC_ORDER);
+#ifdef CONFIG_64BIT
+        pmd = vmem_alloc_pages(2);
         if (!pmd)
                 return NULL;
-        for (i = 0; i < PTRS_PER_PMD; i++)
-                pmd_clear_kernel(pmd + i);
+        clear_table((unsigned long *) pmd, _SEGMENT_ENTRY_EMPTY, PAGE_SIZE*4);
+#endif
         return pmd;
 }
 
 static inline pte_t *vmem_pte_alloc(void)
 {
-        pte_t *pte;
-        pte_t empty_pte;
-        int i;
+        pte_t *pte = vmem_alloc_pages(0);
 
-        pte = vmem_alloc_pages(PTE_ALLOC_ORDER);
         if (!pte)
                 return NULL;
-        pte_val(empty_pte) = _PAGE_TYPE_EMPTY;
-        for (i = 0; i < PTRS_PER_PTE; i++)
-                pte[i] = empty_pte;
+        clear_table((unsigned long *) pte, _PAGE_TYPE_EMPTY, PAGE_SIZE);
         return pte;
 }
 
diff --git a/include/asm-s390/mmu_context.h b/include/asm-s390/mmu_context.h
index 501cb9b06314..05b842126b99 100644
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -21,45 +21,43 @@
 
 #ifndef __s390x__
 #define LCTL_OPCODE "lctl"
-#define PGTABLE_BITS (_SEGMENT_TABLE|USER_STD_MASK)
 #else
 #define LCTL_OPCODE "lctlg"
-#define PGTABLE_BITS (_REGION_TABLE|USER_STD_MASK)
 #endif
 
-static inline void enter_lazy_tlb(struct mm_struct *mm,
-                                  struct task_struct *tsk)
+static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
 {
+        pgd_t *pgd = mm->pgd;
+        unsigned long asce_bits;
+
+        /* Calculate asce bits from the first pgd table entry. */
+        asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
+#ifdef CONFIG_64BIT
+        asce_bits |= _ASCE_TYPE_REGION3;
+#endif
+        S390_lowcore.user_asce = asce_bits | __pa(pgd);
+        if (switch_amode) {
+                /* Load primary space page table origin. */
+                pgd_t *shadow_pgd = get_shadow_table(pgd) ? : pgd;
+                S390_lowcore.user_exec_asce = asce_bits | __pa(shadow_pgd);
+                asm volatile(LCTL_OPCODE" 1,1,%0\n"
+                             : : "m" (S390_lowcore.user_exec_asce) );
+        } else
+                /* Load home space page table origin. */
+                asm volatile(LCTL_OPCODE" 13,13,%0"
+                             : : "m" (S390_lowcore.user_asce) );
 }
 
 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
                              struct task_struct *tsk)
 {
-        pgd_t *shadow_pgd = get_shadow_pgd(next->pgd);
-
-        if (prev != next) {
-                S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
-                                         PGTABLE_BITS;
-                if (shadow_pgd) {
-                        /* Load primary/secondary space page table origin. */
-                        S390_lowcore.user_exec_asce =
-                                (__pa(shadow_pgd) & PAGE_MASK) | PGTABLE_BITS;
-                        asm volatile(LCTL_OPCODE" 1,1,%0\n"
-                                     LCTL_OPCODE" 7,7,%1"
-                                     : : "m" (S390_lowcore.user_exec_asce),
-                                         "m" (S390_lowcore.user_asce) );
-                } else if (switch_amode) {
-                        /* Load primary space page table origin. */
-                        asm volatile(LCTL_OPCODE" 1,1,%0"
-                                     : : "m" (S390_lowcore.user_asce) );
-                } else
-                        /* Load home space page table origin. */
-                        asm volatile(LCTL_OPCODE" 13,13,%0"
-                                     : : "m" (S390_lowcore.user_asce) );
-        }
+        if (unlikely(prev == next))
+                return;
         cpu_set(smp_processor_id(), next->cpu_vm_mask);
+        update_mm(next, tsk);
 }
 
+#define enter_lazy_tlb(mm,tsk)  do { } while (0)
 #define deactivate_mm(tsk,mm)   do { } while (0)
 
 static inline void activate_mm(struct mm_struct *prev,
diff --git a/include/asm-s390/pgalloc.h b/include/asm-s390/pgalloc.h
index 6cbbfe4f6749..229b0bd59331 100644
--- a/include/asm-s390/pgalloc.h
+++ b/include/asm-s390/pgalloc.h
@@ -19,114 +19,75 @@
 
 #define check_pgt_cache()       do {} while (0)
 
-/*
- * Page allocation orders.
- */
-#ifndef __s390x__
-# define PTE_ALLOC_ORDER        0
-# define PMD_ALLOC_ORDER        0
-# define PGD_ALLOC_ORDER        1
-#else /* __s390x__ */
-# define PTE_ALLOC_ORDER        0
-# define PMD_ALLOC_ORDER        2
-# define PGD_ALLOC_ORDER        2
-#endif /* __s390x__ */
+unsigned long *crst_table_alloc(struct mm_struct *, int);
+void crst_table_free(unsigned long *);
 
-/*
- * Allocate and free page tables. The xxx_kernel() versions are
- * used to allocate a kernel page table - this turns on ASN bits
- * if any.
- */
+unsigned long *page_table_alloc(int);
+void page_table_free(unsigned long *);
 
-static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
 {
-        pgd_t *pgd = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ALLOC_ORDER);
-        int i;
-
-        if (!pgd)
-                return NULL;
-        if (s390_noexec) {
-                pgd_t *shadow_pgd = (pgd_t *)
-                        __get_free_pages(GFP_KERNEL, PGD_ALLOC_ORDER);
-                struct page *page = virt_to_page(pgd);
-
-                if (!shadow_pgd) {
-                        free_pages((unsigned long) pgd, PGD_ALLOC_ORDER);
-                        return NULL;
-                }
-                page->lru.next = (void *) shadow_pgd;
-        }
-        for (i = 0; i < PTRS_PER_PGD; i++)
-#ifndef __s390x__
-                pmd_clear(pmd_offset(pgd + i, i*PGDIR_SIZE));
+        *s = val;
+        n = (n / 256) - 1;
+        asm volatile(
+#ifdef CONFIG_64BIT
+                "       mvc     8(248,%0),0(%0)\n"
 #else
-                pgd_clear(pgd + i);
+                "       mvc     4(252,%0),0(%0)\n"
 #endif
-        return pgd;
+                "0:     mvc     256(256,%0),0(%0)\n"
+                "       la      %0,256(%0)\n"
+                "       brct    %1,0b\n"
+                : "+a" (s), "+d" (n));
 }
 
-static inline void pgd_free(pgd_t *pgd)
+static inline void crst_table_init(unsigned long *crst, unsigned long entry)
 {
-        pgd_t *shadow_pgd = get_shadow_pgd(pgd);
-
-        if (shadow_pgd)
-                free_pages((unsigned long) shadow_pgd, PGD_ALLOC_ORDER);
-        free_pages((unsigned long) pgd, PGD_ALLOC_ORDER);
+        clear_table(crst, entry, sizeof(unsigned long)*2048);
+        crst = get_shadow_table(crst);
+        if (crst)
+                clear_table(crst, entry, sizeof(unsigned long)*2048);
 }
 
 #ifndef __s390x__
-/*
- * page middle directory allocation/free routines.
- * We use pmd cache only on s390x, so these are dummy routines. This
- * code never triggers because the pgd will always be present.
- */
-#define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); })
-#define pmd_free(x)                     do { } while (0)
-#define pgd_populate(mm, pmd, pte)      BUG()
+
+static inline unsigned long pgd_entry_type(struct mm_struct *mm)
+{
+        return _SEGMENT_ENTRY_EMPTY;
+}
+
+#define pmd_alloc_one(mm,address)               ({ BUG(); ((pmd_t *)2); })
+#define pmd_free(x)                             do { } while (0)
+
+#define pgd_populate(mm, pmd, pte)              BUG()
 #define pgd_populate_kernel(mm, pmd, pte)       BUG()
+
 #else /* __s390x__ */
-static inline pmd_t * pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
+
+static inline unsigned long pgd_entry_type(struct mm_struct *mm)
 {
-        pmd_t *pmd = (pmd_t *) __get_free_pages(GFP_KERNEL, PMD_ALLOC_ORDER);
-        int i;
-
-        if (!pmd)
-                return NULL;
-        if (s390_noexec) {
-                pmd_t *shadow_pmd = (pmd_t *)
-                        __get_free_pages(GFP_KERNEL, PMD_ALLOC_ORDER);
-                struct page *page = virt_to_page(pmd);
-
-                if (!shadow_pmd) {
-                        free_pages((unsigned long) pmd, PMD_ALLOC_ORDER);
-                        return NULL;
-                }
-                page->lru.next = (void *) shadow_pmd;
-        }
-        for (i=0; i < PTRS_PER_PMD; i++)
-                pmd_clear(pmd + i);
-        return pmd;
+        return _REGION3_ENTRY_EMPTY;
 }
 
-static inline void pmd_free (pmd_t *pmd)
+static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
 {
-        pmd_t *shadow_pmd = get_shadow_pmd(pmd);
-
-        if (shadow_pmd)
-                free_pages((unsigned long) shadow_pmd, PMD_ALLOC_ORDER);
-        free_pages((unsigned long) pmd, PMD_ALLOC_ORDER);
+        unsigned long *crst = crst_table_alloc(mm, s390_noexec);
+        if (crst)
+                crst_table_init(crst, _SEGMENT_ENTRY_EMPTY);
+        return (pmd_t *) crst;
 }
+#define pmd_free(pmd) crst_table_free((unsigned long *) pmd)
 
-static inline void
-pgd_populate_kernel(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
+static inline void pgd_populate_kernel(struct mm_struct *mm,
+                                       pgd_t *pgd, pmd_t *pmd)
 {
-        pgd_val(*pgd) = _PGD_ENTRY | __pa(pmd);
+        pgd_val(*pgd) = _REGION3_ENTRY | __pa(pmd);
 }
 
 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
 {
-        pgd_t *shadow_pgd = get_shadow_pgd(pgd);
-        pmd_t *shadow_pmd = get_shadow_pmd(pmd);
+        pgd_t *shadow_pgd = get_shadow_table(pgd);
+        pmd_t *shadow_pmd = get_shadow_table(pmd);
 
         if (shadow_pgd && shadow_pmd)
                 pgd_populate_kernel(mm, shadow_pgd, shadow_pmd);
@@ -135,17 +96,26 @@ static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
 
 #endif /* __s390x__ */
 
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+        unsigned long *crst = crst_table_alloc(mm, s390_noexec);
+        if (crst)
+                crst_table_init(crst, pgd_entry_type(mm));
+        return (pgd_t *) crst;
+}
+#define pgd_free(pgd) crst_table_free((unsigned long *) pgd)
+
 static inline void 
 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
 {
 #ifndef __s390x__
-        pmd_val(pmd[0]) = _PAGE_TABLE + __pa(pte);
-        pmd_val(pmd[1]) = _PAGE_TABLE + __pa(pte+256);
-        pmd_val(pmd[2]) = _PAGE_TABLE + __pa(pte+512);
-        pmd_val(pmd[3]) = _PAGE_TABLE + __pa(pte+768);
+        pmd_val(pmd[0]) = _SEGMENT_ENTRY + __pa(pte);
+        pmd_val(pmd[1]) = _SEGMENT_ENTRY + __pa(pte+256);
+        pmd_val(pmd[2]) = _SEGMENT_ENTRY + __pa(pte+512);
+        pmd_val(pmd[3]) = _SEGMENT_ENTRY + __pa(pte+768);
 #else /* __s390x__ */
-        pmd_val(*pmd) = _PMD_ENTRY + __pa(pte);
-        pmd_val1(*pmd) = _PMD_ENTRY + __pa(pte+256);
+        pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
+        pmd_val1(*pmd) = _SEGMENT_ENTRY + __pa(pte+256);
 #endif /* __s390x__ */
 }
 
@@ -153,7 +123,7 @@ static inline void
 pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *page)
 {
         pte_t *pte = (pte_t *)page_to_phys(page);
-        pmd_t *shadow_pmd = get_shadow_pmd(pmd);
+        pmd_t *shadow_pmd = get_shadow_table(pmd);
         pte_t *shadow_pte = get_shadow_pte(pte);
 
         pmd_populate_kernel(mm, pmd, pte);
@@ -164,57 +134,14 @@ pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *page)
 /*
  * page table entry allocation/free routines.
  */
-static inline pte_t *
-pte_alloc_one_kernel(struct mm_struct *mm, unsigned long vmaddr)
-{
-        pte_t *pte = (pte_t *) __get_free_page(GFP_KERNEL|__GFP_REPEAT);
-        int i;
-
-        if (!pte)
-                return NULL;
-        if (s390_noexec) {
-                pte_t *shadow_pte = (pte_t *)
-                        __get_free_page(GFP_KERNEL|__GFP_REPEAT);
-                struct page *page = virt_to_page(pte);
-
-                if (!shadow_pte) {
-                        free_page((unsigned long) pte);
-                        return NULL;
-                }
-                page->lru.next = (void *) shadow_pte;
-        }
-        for (i=0; i < PTRS_PER_PTE; i++) {
-                pte_clear(mm, vmaddr, pte + i);
-                vmaddr += PAGE_SIZE;
-        }
-        return pte;
-}
-
-static inline struct page *
-pte_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
-{
-        pte_t *pte = pte_alloc_one_kernel(mm, vmaddr);
-        if (pte)
-                return virt_to_page(pte);
-        return NULL;
-}
-
-static inline void pte_free_kernel(pte_t *pte)
-{
-        pte_t *shadow_pte = get_shadow_pte(pte);
-
-        if (shadow_pte)
-                free_page((unsigned long) shadow_pte);
-        free_page((unsigned long) pte);
-}
-
-static inline void pte_free(struct page *pte)
-{
-        struct page *shadow_page = get_shadow_page(pte);
-
-        if (shadow_page)
-                __free_page(shadow_page);
-        __free_page(pte);
-}
+#define pte_alloc_one_kernel(mm, vmaddr) \
+        ((pte_t *) page_table_alloc(s390_noexec))
+#define pte_alloc_one(mm, vmaddr) \
+        virt_to_page(page_table_alloc(s390_noexec))
+
+#define pte_free_kernel(pte) \
+        page_table_free((unsigned long *) pte)
+#define pte_free(pte) \
+        page_table_free((unsigned long *) page_to_phys((struct page *) pte))
 
 #endif /* _S390_PGALLOC_H */
diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h
index b424ab21f8bd..f9f59a805e5d 100644
--- a/include/asm-s390/pgtable.h
+++ b/include/asm-s390/pgtable.h
@@ -35,9 +35,6 @@
 #include <asm/bug.h>
 #include <asm/processor.h>
 
-struct vm_area_struct; /* forward declaration (include/linux/mm.h) */
-struct mm_struct;
-
 extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
 extern void paging_init(void);
 extern void vmem_map_init(void);
@@ -221,6 +218,8 @@ extern unsigned long vmalloc_end;
 /* 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 */
 
@@ -264,60 +263,75 @@ extern unsigned long vmalloc_end;
 
 #ifndef __s390x__
 
-/* Bits in the segment table entry */
-#define _PAGE_TABLE_LEN 0xf            /* only full page-tables            */
-#define _PAGE_TABLE_COM 0x10           /* common page-table                */
-#define _PAGE_TABLE_INV 0x20           /* invalid page-table               */
-#define _SEG_PRESENT    0x001          /* Software (overlap with PTL)      */
-
-/* Bits int the storage key */
-#define _PAGE_CHANGED    0x02          /* HW changed bit                   */
-#define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
-
-#define _USER_SEG_TABLE_LEN    0x7f    /* user-segment-table up to 2 GB    */
-#define _KERNEL_SEG_TABLE_LEN  0x7f    /* kernel-segment-table up to 2 GB  */
-
-/*
- * User and Kernel pagetables are identical
- */
-#define _PAGE_TABLE     _PAGE_TABLE_LEN
-#define _KERNPG_TABLE   _PAGE_TABLE_LEN
-
-/*
- * The Kernel segment-tables includes the User segment-table
- */
+/* 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            */
 
-#define _SEGMENT_TABLE  (_USER_SEG_TABLE_LEN|0x80000000|0x100)
-#define _KERNSEG_TABLE  _KERNEL_SEG_TABLE_LEN
+/* 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 USER_STD_MASK   0x00000080UL
+#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 _PMD_ENTRY_INV   0x20          /* invalid segment table entry      */
-#define _PMD_ENTRY       0x00        
+#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      */
 
-/* Bits in the region third table entry */
-#define _PGD_ENTRY_INV   0x20          /* invalid region table entry       */
-#define _PGD_ENTRY       0x07
+#define _SEGMENT_ENTRY          (0)
+#define _SEGMENT_ENTRY_EMPTY    (_SEGMENT_ENTRY_INV)
+
+#endif /* __s390x__ */
 
 /*
- * User and kernel page directory
+ * 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 _REGION_THIRD       0x4
-#define _REGION_THIRD_LEN   0x3 
-#define _REGION_TABLE       (_REGION_THIRD|_REGION_THIRD_LEN|0x40|0x100)
-#define _KERN_REGION_TABLE  (_REGION_THIRD|_REGION_THIRD_LEN)
-
-#define USER_STD_MASK           0x0000000000000080UL
+#define _ASCE_USER_BITS         (_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \
+                                 _ASCE_ALT_EVENT)
 
-/* Bits in the storage key */
+/* Bits int the storage key */
 #define _PAGE_CHANGED    0x02          /* HW changed bit                   */
 #define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
 
-#endif /* __s390x__ */
-
 /*
  * Page protection definitions.
  */
@@ -358,65 +372,38 @@ extern unsigned long vmalloc_end;
 #define __S111  PAGE_EX_RW
 
 #ifndef __s390x__
-# define PMD_SHADOW_SHIFT       1
-# define PGD_SHADOW_SHIFT       1
+# define PxD_SHADOW_SHIFT       1
 #else /* __s390x__ */
-# define PMD_SHADOW_SHIFT       2
-# define PGD_SHADOW_SHIFT       2
+# define PxD_SHADOW_SHIFT       2
 #endif /* __s390x__ */
 
 static inline struct page *get_shadow_page(struct page *page)
 {
-        if (s390_noexec && !list_empty(&page->lru))
-                return virt_to_page(page->lru.next);
-        return NULL;
-}
-
-static inline pte_t *get_shadow_pte(pte_t *ptep)
-{
-        unsigned long pteptr = (unsigned long) (ptep);
-
-        if (s390_noexec) {
-                unsigned long offset = pteptr & (PAGE_SIZE - 1);
-                void *addr = (void *) (pteptr ^ offset);
-                struct page *page = virt_to_page(addr);
-                if (!list_empty(&page->lru))
-                        return (pte_t *) ((unsigned long) page->lru.next |
-                                                                offset);
-        }
+        if (s390_noexec && page->index)
+                return virt_to_page((void *)(addr_t) page->index);
         return NULL;
 }
 
-static inline pmd_t *get_shadow_pmd(pmd_t *pmdp)
+static inline void *get_shadow_pte(void *table)
 {
-        unsigned long pmdptr = (unsigned long) (pmdp);
+        unsigned long addr, offset;
+        struct page *page;
 
-        if (s390_noexec) {
-                unsigned long offset = pmdptr &
-                                ((PAGE_SIZE << PMD_SHADOW_SHIFT) - 1);
-                void *addr = (void *) (pmdptr ^ offset);
-                struct page *page = virt_to_page(addr);
-                if (!list_empty(&page->lru))
-                        return (pmd_t *) ((unsigned long) page->lru.next |
-                                                                offset);
-        }
-        return NULL;
+        addr = (unsigned long) table;
+        offset = addr & (PAGE_SIZE - 1);
+        page = virt_to_page((void *)(addr ^ offset));
+        return (void *)(addr_t)(page->index ? (page->index | offset) : 0UL);
 }
 
-static inline pgd_t *get_shadow_pgd(pgd_t *pgdp)
+static inline void *get_shadow_table(void *table)
 {
-        unsigned long pgdptr = (unsigned long) (pgdp);
+        unsigned long addr, offset;
+        struct page *page;
 
-        if (s390_noexec) {
-                unsigned long offset = pgdptr &
-                                ((PAGE_SIZE << PGD_SHADOW_SHIFT) - 1);
-                void *addr = (void *) (pgdptr ^ offset);
-                struct page *page = virt_to_page(addr);
-                if (!list_empty(&page->lru))
-                        return (pgd_t *) ((unsigned long) page->lru.next |
-                                                                offset);
-        }
-        return NULL;
+        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);
 }
 
 /*
@@ -448,47 +435,42 @@ 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 pmd_present(pmd_t pmd) { return pmd_val(pmd) & _SEG_PRESENT; }
-static inline int pmd_none(pmd_t pmd)    { return pmd_val(pmd) & _PAGE_TABLE_INV; }
-static inline int pmd_bad(pmd_t pmd)
-{
-        return (pmd_val(pmd) & (~PAGE_MASK & ~_PAGE_TABLE_INV)) != _PAGE_TABLE;
-}
-
 #else /* __s390x__ */
 
 static inline int pgd_present(pgd_t pgd)
 {
-        return (pgd_val(pgd) & ~PAGE_MASK) == _PGD_ENTRY;
+        return pgd_val(pgd) & _REGION_ENTRY_ORIGIN;
 }
 
 static inline int pgd_none(pgd_t pgd)
 {
-        return pgd_val(pgd) & _PGD_ENTRY_INV;
+        return pgd_val(pgd) & _REGION_ENTRY_INV;
 }
 
 static inline int pgd_bad(pgd_t pgd)
 {
-        return (pgd_val(pgd) & (~PAGE_MASK & ~_PGD_ENTRY_INV)) != _PGD_ENTRY;
+        unsigned long mask = ~_REGION_ENTRY_ORIGIN & ~_REGION_ENTRY_INV;
+        return (pgd_val(pgd) & mask) != _REGION3_ENTRY;
 }
 
+#endif /* __s390x__ */
+
 static inline int pmd_present(pmd_t pmd)
 {
-        return (pmd_val(pmd) & ~PAGE_MASK) == _PMD_ENTRY;
+        return pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN;
 }
 
 static inline int pmd_none(pmd_t pmd)
 {
-        return pmd_val(pmd) & _PMD_ENTRY_INV;
+        return pmd_val(pmd) & _SEGMENT_ENTRY_INV;
 }
 
 static inline int pmd_bad(pmd_t pmd)
 {
-        return (pmd_val(pmd) & (~PAGE_MASK & ~_PMD_ENTRY_INV)) != _PMD_ENTRY;
+        unsigned long mask = ~_SEGMENT_ENTRY_ORIGIN & ~_SEGMENT_ENTRY_INV;
+        return (pmd_val(pmd) & mask) != _SEGMENT_ENTRY;
 }
 
-#endif /* __s390x__ */
-
 static inline int pte_none(pte_t pte)
 {
         return (pte_val(pte) & _PAGE_INVALID) && !(pte_val(pte) & _PAGE_SWT);
@@ -548,31 +530,22 @@ static inline void pgd_clear(pgd_t * pgdp)      { }
 
 static inline void pmd_clear_kernel(pmd_t * pmdp)
 {
-        pmd_val(pmdp[0]) = _PAGE_TABLE_INV;
-        pmd_val(pmdp[1]) = _PAGE_TABLE_INV;
-        pmd_val(pmdp[2]) = _PAGE_TABLE_INV;
-        pmd_val(pmdp[3]) = _PAGE_TABLE_INV;
-}
-
-static inline void pmd_clear(pmd_t * pmdp)
-{
-        pmd_t *shadow_pmd = get_shadow_pmd(pmdp);
-
-        pmd_clear_kernel(pmdp);
-        if (shadow_pmd)
-                pmd_clear_kernel(shadow_pmd);
+        pmd_val(pmdp[0]) = _SEGMENT_ENTRY_EMPTY;
+        pmd_val(pmdp[1]) = _SEGMENT_ENTRY_EMPTY;
+        pmd_val(pmdp[2]) = _SEGMENT_ENTRY_EMPTY;
+        pmd_val(pmdp[3]) = _SEGMENT_ENTRY_EMPTY;
 }
 
 #else /* __s390x__ */
 
 static inline void pgd_clear_kernel(pgd_t * pgdp)
 {
-        pgd_val(*pgdp) = _PGD_ENTRY_INV | _PGD_ENTRY;
+        pgd_val(*pgdp) = _REGION3_ENTRY_EMPTY;
 }
 
 static inline void pgd_clear(pgd_t * pgdp)
 {
-        pgd_t *shadow_pgd = get_shadow_pgd(pgdp);
+        pgd_t *shadow_pgd = get_shadow_table(pgdp);
 
         pgd_clear_kernel(pgdp);
         if (shadow_pgd)
@@ -581,21 +554,21 @@ static inline void pgd_clear(pgd_t * pgdp)
 
 static inline void pmd_clear_kernel(pmd_t * pmdp)
 {
-        pmd_val(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
-        pmd_val1(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
+        pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
+        pmd_val1(*pmdp) = _SEGMENT_ENTRY_EMPTY;
 }
 
+#endif /* __s390x__ */
+
 static inline void pmd_clear(pmd_t * pmdp)
 {
-        pmd_t *shadow_pmd = get_shadow_pmd(pmdp);
+        pmd_t *shadow_pmd = get_shadow_table(pmdp);
 
         pmd_clear_kernel(pmdp);
         if (shadow_pmd)
                 pmd_clear_kernel(shadow_pmd);
 }
 
-#endif /* __s390x__ */
-
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
         pte_t *shadow_pte = get_shadow_pte(ptep);
diff --git a/include/asm-s390/processor.h b/include/asm-s390/processor.h
index 81efccc63942..21d40a19355e 100644
--- a/include/asm-s390/processor.h
+++ b/include/asm-s390/processor.h
@@ -127,12 +127,6 @@ struct stack_frame {
 
 #define ARCH_MIN_TASKALIGN      8
 
-#ifndef __s390x__
-# define __SWAPPER_PG_DIR __pa(&swapper_pg_dir[0]) + _SEGMENT_TABLE
-#else /* __s390x__ */
-# define __SWAPPER_PG_DIR __pa(&swapper_pg_dir[0]) + _REGION_TABLE
-#endif /* __s390x__ */
-
 #define INIT_THREAD {                                                   \
         .ksp = sizeof(init_stack) + (unsigned long) &init_stack,        \
 }
diff --git a/include/asm-s390/tlbflush.h b/include/asm-s390/tlbflush.h
index 3a9985fbc8af..a69bd2490d52 100644
--- a/include/asm-s390/tlbflush.h
+++ b/include/asm-s390/tlbflush.h
@@ -61,7 +61,7 @@ static inline void __tlb_flush_mm(struct mm_struct * mm)
          * only ran on the local cpu.
          */
         if (MACHINE_HAS_IDTE) {
-                pgd_t *shadow_pgd = get_shadow_pgd(mm->pgd);
+                pgd_t *shadow_pgd = get_shadow_table(mm->pgd);
 
                 if (shadow_pgd)
                         __tlb_flush_idte(shadow_pgd);