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-generic/mm_hooks.h>
14
15/*
16 * get a new mmu context.. S390 don't know about contexts.
17 */
18#define init_new_context(tsk,mm)        0
19
20#define destroy_context(mm)             do { } while (0)
21
22#ifndef __s390x__
23#define LCTL_OPCODE "lctl"
24#define PGTABLE_BITS (_SEGMENT_TABLE|USER_STD_MASK)
25#else
26#define LCTL_OPCODE "lctlg"
27#define PGTABLE_BITS (_REGION_TABLE|USER_STD_MASK)
28#endif
29
30static inline void enter_lazy_tlb(struct mm_struct *mm,
31                                  struct task_struct *tsk)
32{
33}
34
35static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
36			     struct task_struct *tsk)
37{
38	pgd_t *shadow_pgd = get_shadow_pgd(next->pgd);
39
40	if (prev != next) {
41		S390_lowcore.user_asce = (__pa(next->pgd) & PAGE_MASK) |
42					 PGTABLE_BITS;
43		if (shadow_pgd) {
44			/* Load primary/secondary space page table origin. */
45			S390_lowcore.user_exec_asce =
46				(__pa(shadow_pgd) & PAGE_MASK) | PGTABLE_BITS;
47			asm volatile(LCTL_OPCODE" 1,1,%0\n"
48				     LCTL_OPCODE" 7,7,%1"
49				     : : "m" (S390_lowcore.user_exec_asce),
50					 "m" (S390_lowcore.user_asce) );
51		} else if (switch_amode) {
52			/* Load primary space page table origin. */
53			asm volatile(LCTL_OPCODE" 1,1,%0"
54				     : : "m" (S390_lowcore.user_asce) );
55		} else
56			/* Load home space page table origin. */
57			asm volatile(LCTL_OPCODE" 13,13,%0"
58				     : : "m" (S390_lowcore.user_asce) );
59	}
60	cpu_set(smp_processor_id(), next->cpu_vm_mask);
61}
62
63#define deactivate_mm(tsk,mm)	do { } while (0)
64
65static inline void activate_mm(struct mm_struct *prev,
66                               struct mm_struct *next)
67{
68        switch_mm(prev, next, current);
69	set_fs(current->thread.mm_segment);
70}
71
72#endif /* __S390_MMU_CONTEXT_H */
73