- Update to 2.6.25-rc3.

[linux-flexiantxendom0-3.2.10.git] / include / asm-s390 / mmu_context.h

diff --git a/include/asm-s390/mmu_context.h b/include/asm-s390/mmu_context.h
index 05b8421..b5a34c6 100644 (file)
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -10,12 +10,21 @@
 #define __S390_MMU_CONTEXT_H
 
 #include <asm/pgalloc.h>
+#include <asm/uaccess.h>
 #include <asm-generic/mm_hooks.h>
 
-/*
- * get a new mmu context.. S390 don't know about contexts.
- */
-#define init_new_context(tsk,mm)        0
+static inline int init_new_context(struct task_struct *tsk,
+                                  struct mm_struct *mm)
+{
+       mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
+#ifdef CONFIG_64BIT
+       mm->context.asce_bits |= _ASCE_TYPE_REGION3;
+#endif
+       mm->context.noexec = s390_noexec;
+       mm->context.asce_limit = STACK_TOP_MAX;
+       crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
+       return 0;
+}
 
 #define destroy_context(mm)             do { } while (0)
 
@@ -28,31 +37,24 @@
 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);
+       S390_lowcore.user_asce = mm->context.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);
+               pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd;
+               S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(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) );
+       set_fs(current->thread.mm_segment);
 }
 
 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
                             struct task_struct *tsk)
 {
-       if (unlikely(prev == next))
-               return;
        cpu_set(smp_processor_id(), next->cpu_vm_mask);
        update_mm(next, tsk);
 }
@@ -64,7 +66,6 @@ static inline void activate_mm(struct mm_struct *prev,
                                struct mm_struct *next)
 {
         switch_mm(prev, next, current);
-       set_fs(current->thread.mm_segment);
 }
 
 #endif /* __S390_MMU_CONTEXT_H */