1 /*
2 * S390 version
3 *
4 * Derived from "include/asm-i386/mmu_context.h"
5 */
6
7 #ifndef __S390_MMU_CONTEXT_H
8 #define __S390_MMU_CONTEXT_H
9
10 #include <asm/pgalloc.h>
11 #include <asm/uaccess.h>
12 #include <asm/tlbflush.h>
13 #include <asm/ctl_reg.h>
14
init_new_context(struct task_struct * tsk,struct mm_struct * mm)15 static inline int init_new_context(struct task_struct *tsk,
16 struct mm_struct *mm)
17 {
18 cpumask_clear(&mm->context.cpu_attach_mask);
19 atomic_set(&mm->context.attach_count, 0);
20 mm->context.flush_mm = 0;
21 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
22 #ifdef CONFIG_64BIT
23 mm->context.asce_bits |= _ASCE_TYPE_REGION3;
24 #endif
25 mm->context.has_pgste = 0;
26 mm->context.use_skey = 0;
27 mm->context.asce_limit = STACK_TOP_MAX;
28 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
29 return 0;
30 }
31
32 #define destroy_context(mm) do { } while (0)
33
set_user_asce(struct mm_struct * mm)34 static inline void set_user_asce(struct mm_struct *mm)
35 {
36 S390_lowcore.user_asce = mm->context.asce_bits | __pa(mm->pgd);
37 if (current->thread.mm_segment.ar4)
38 __ctl_load(S390_lowcore.user_asce, 7, 7);
39 set_cpu_flag(CIF_ASCE);
40 }
41
clear_user_asce(void)42 static inline void clear_user_asce(void)
43 {
44 S390_lowcore.user_asce = S390_lowcore.kernel_asce;
45
46 __ctl_load(S390_lowcore.user_asce, 1, 1);
47 __ctl_load(S390_lowcore.user_asce, 7, 7);
48 }
49
load_kernel_asce(void)50 static inline void load_kernel_asce(void)
51 {
52 unsigned long asce;
53
54 __ctl_store(asce, 1, 1);
55 if (asce != S390_lowcore.kernel_asce)
56 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
57 set_cpu_flag(CIF_ASCE);
58 }
59
switch_mm(struct mm_struct * prev,struct mm_struct * next,struct task_struct * tsk)60 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
61 struct task_struct *tsk)
62 {
63 int cpu = smp_processor_id();
64
65 if (prev == next)
66 return;
67 if (MACHINE_HAS_TLB_LC)
68 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
69 /* Clear old ASCE by loading the kernel ASCE. */
70 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
71 __ctl_load(S390_lowcore.kernel_asce, 7, 7);
72 atomic_inc(&next->context.attach_count);
73 atomic_dec(&prev->context.attach_count);
74 if (MACHINE_HAS_TLB_LC)
75 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
76 S390_lowcore.user_asce = next->context.asce_bits | __pa(next->pgd);
77 }
78
79 #define finish_arch_post_lock_switch finish_arch_post_lock_switch
finish_arch_post_lock_switch(void)80 static inline void finish_arch_post_lock_switch(void)
81 {
82 struct task_struct *tsk = current;
83 struct mm_struct *mm = tsk->mm;
84
85 load_kernel_asce();
86 if (mm) {
87 preempt_disable();
88 while (atomic_read(&mm->context.attach_count) >> 16)
89 cpu_relax();
90
91 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
92 if (mm->context.flush_mm)
93 __tlb_flush_mm(mm);
94 preempt_enable();
95 }
96 set_fs(current->thread.mm_segment);
97 }
98
99 #define enter_lazy_tlb(mm,tsk) do { } while (0)
100 #define deactivate_mm(tsk,mm) do { } while (0)
101
activate_mm(struct mm_struct * prev,struct mm_struct * next)102 static inline void activate_mm(struct mm_struct *prev,
103 struct mm_struct *next)
104 {
105 switch_mm(prev, next, current);
106 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
107 set_user_asce(next);
108 }
109
arch_dup_mmap(struct mm_struct * oldmm,struct mm_struct * mm)110 static inline void arch_dup_mmap(struct mm_struct *oldmm,
111 struct mm_struct *mm)
112 {
113 #ifdef CONFIG_64BIT
114 if (oldmm->context.asce_limit < mm->context.asce_limit)
115 crst_table_downgrade(mm, oldmm->context.asce_limit);
116 #endif
117 }
118
arch_exit_mmap(struct mm_struct * mm)119 static inline void arch_exit_mmap(struct mm_struct *mm)
120 {
121 }
122
123 #endif /* __S390_MMU_CONTEXT_H */
124