[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>

1 files changed, 24 insertions, 26 deletions

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,