1 /*
2  *  include/asm-s390/mmu_context.h
3  *
4  *  S390 version
5  *
6  *  Derived from "include/asm-i386/mmu_context.h"
7  */
8 
9 #ifndef __S390_MMU_CONTEXT_H
10 #define __S390_MMU_CONTEXT_H
11 
12 #include <asm/pgalloc.h>
13 #include <asm/uaccess.h>
14 #include <asm-generic/mm_hooks.h>
15 
16 static inline int init_new_context(struct task_struct *tsk,
17 				   struct mm_struct *mm)
18 {
19 	mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
20 #ifdef CONFIG_64BIT
21 	mm->context.asce_bits |= _ASCE_TYPE_REGION3;
22 #endif
23 	if (current->mm->context.pgstes) {
24 		mm->context.noexec = 0;
25 		mm->context.pgstes = 1;
26 	} else {
27 		mm->context.noexec = s390_noexec;
28 		mm->context.pgstes = 0;
29 	}
30 	mm->context.asce_limit = STACK_TOP_MAX;
31 	crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
32 	return 0;
33 }
34 
35 #define destroy_context(mm)             do { } while (0)
36 
37 #ifndef __s390x__
38 #define LCTL_OPCODE "lctl"
39 #else
40 #define LCTL_OPCODE "lctlg"
41 #endif
42 
43 static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
44 {
45 	pgd_t *pgd = mm->pgd;
46 
47 	S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
48 	if (switch_amode) {
49 		/* Load primary space page table origin. */
50 		pgd = mm->context.noexec ? get_shadow_table(pgd) : pgd;
51 		S390_lowcore.user_exec_asce = mm->context.asce_bits | __pa(pgd);
52 		asm volatile(LCTL_OPCODE" 1,1,%0\n"
53 			     : : "m" (S390_lowcore.user_exec_asce) );
54 	} else
55 		/* Load home space page table origin. */
56 		asm volatile(LCTL_OPCODE" 13,13,%0"
57 			     : : "m" (S390_lowcore.user_asce) );
58 	set_fs(current->thread.mm_segment);
59 }
60 
61 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
62 			     struct task_struct *tsk)
63 {
64 	cpu_set(smp_processor_id(), next->cpu_vm_mask);
65 	update_mm(next, tsk);
66 }
67 
68 #define enter_lazy_tlb(mm,tsk)	do { } while (0)
69 #define deactivate_mm(tsk,mm)	do { } while (0)
70 
71 static inline void activate_mm(struct mm_struct *prev,
72                                struct mm_struct *next)
73 {
74         switch_mm(prev, next, current);
75 }
76 
77 #endif /* __S390_MMU_CONTEXT_H */
78