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Linux kernel mirror (for testing)
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linux
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/tlbflush.h>
15#include <asm-generic/mm_hooks.h>
16
17static inline int init_new_context(struct task_struct *tsk,
18 struct mm_struct *mm)
19{
20 atomic_set(&mm->context.attach_count, 0);
21 mm->context.flush_mm = 0;
22 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
23#ifdef CONFIG_64BIT
24 mm->context.asce_bits |= _ASCE_TYPE_REGION3;
25#endif
26 if (current->mm && current->mm->context.alloc_pgste) {
27 /*
28 * alloc_pgste indicates, that any NEW context will be created
29 * with extended page tables. The old context is unchanged. The
30 * page table allocation and the page table operations will
31 * look at has_pgste to distinguish normal and extended page
32 * tables. The only way to create extended page tables is to
33 * set alloc_pgste and then create a new context (e.g. dup_mm).
34 * The page table allocation is called after init_new_context
35 * and if has_pgste is set, it will create extended page
36 * tables.
37 */
38 mm->context.has_pgste = 1;
39 mm->context.alloc_pgste = 1;
40 } else {
41 mm->context.has_pgste = 0;
42 mm->context.alloc_pgste = 0;
43 }
44 mm->context.asce_limit = STACK_TOP_MAX;
45 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
46 return 0;
47}
48
49#define destroy_context(mm) do { } while (0)
50
51#ifndef __s390x__
52#define LCTL_OPCODE "lctl"
53#else
54#define LCTL_OPCODE "lctlg"
55#endif
56
57static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
58{
59 pgd_t *pgd = mm->pgd;
60
61 S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
62 if (user_mode != HOME_SPACE_MODE) {
63 /* Load primary space page table origin. */
64 asm volatile(LCTL_OPCODE" 1,1,%0\n"
65 : : "m" (S390_lowcore.user_asce) );
66 } else
67 /* Load home space page table origin. */
68 asm volatile(LCTL_OPCODE" 13,13,%0"
69 : : "m" (S390_lowcore.user_asce) );
70 set_fs(current->thread.mm_segment);
71}
72
73static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
74 struct task_struct *tsk)
75{
76 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
77 update_mm(next, tsk);
78 atomic_dec(&prev->context.attach_count);
79 WARN_ON(atomic_read(&prev->context.attach_count) < 0);
80 atomic_inc(&next->context.attach_count);
81 /* Check for TLBs not flushed yet */
82 if (next->context.flush_mm)
83 __tlb_flush_mm(next);
84}
85
86#define enter_lazy_tlb(mm,tsk) do { } while (0)
87#define deactivate_mm(tsk,mm) do { } while (0)
88
89static inline void activate_mm(struct mm_struct *prev,
90 struct mm_struct *next)
91{
92 switch_mm(prev, next, current);
93}
94
95#endif /* __S390_MMU_CONTEXT_H */