2 * include/asm-s390/mmu_context.h
6 * Derived from "include/asm-i386/mmu_context.h"
9 #ifndef __S390_MMU_CONTEXT_H
10 #define __S390_MMU_CONTEXT_H
12 #include <asm/pgalloc.h>
13 #include <asm/uaccess.h>
14 #include <asm/tlbflush.h>
15 #include <asm/ctl_reg.h>
16 #include <asm-generic/mm_hooks.h>
18 static inline int init_new_context(struct task_struct *tsk,
21 atomic_set(&mm->context.attach_count, 0);
22 mm->context.flush_mm = 0;
23 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
25 mm->context.asce_bits |= _ASCE_TYPE_REGION3;
27 if (current->mm && current->mm->context.alloc_pgste) {
29 * alloc_pgste indicates, that any NEW context will be created
30 * with extended page tables. The old context is unchanged. The
31 * page table allocation and the page table operations will
32 * look at has_pgste to distinguish normal and extended page
33 * tables. The only way to create extended page tables is to
34 * set alloc_pgste and then create a new context (e.g. dup_mm).
35 * The page table allocation is called after init_new_context
36 * and if has_pgste is set, it will create extended page
39 mm->context.has_pgste = 1;
40 mm->context.alloc_pgste = 1;
42 mm->context.has_pgste = 0;
43 mm->context.alloc_pgste = 0;
45 mm->context.asce_limit = STACK_TOP_MAX;
46 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
50 #define destroy_context(mm) do { } while (0)
53 #define LCTL_OPCODE "lctl"
55 #define LCTL_OPCODE "lctlg"
58 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
62 S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
63 if (user_mode != HOME_SPACE_MODE) {
64 /* Load primary space page table origin. */
65 asm volatile(LCTL_OPCODE" 1,1,%0\n"
66 : : "m" (S390_lowcore.user_asce) );
68 /* Load home space page table origin. */
69 asm volatile(LCTL_OPCODE" 13,13,%0"
70 : : "m" (S390_lowcore.user_asce) );
71 set_fs(current->thread.mm_segment);
74 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
75 struct task_struct *tsk)
77 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
79 atomic_dec(&prev->context.attach_count);
80 WARN_ON(atomic_read(&prev->context.attach_count) < 0);
81 atomic_inc(&next->context.attach_count);
82 /* Check for TLBs not flushed yet */
83 if (next->context.flush_mm)
87 #define enter_lazy_tlb(mm,tsk) do { } while (0)
88 #define deactivate_mm(tsk,mm) do { } while (0)
90 static inline void activate_mm(struct mm_struct *prev,
91 struct mm_struct *next)
93 switch_mm(prev, next, current);
96 #endif /* __S390_MMU_CONTEXT_H */