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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * S390 version
4 *
5 * Derived from "include/asm-i386/mmu_context.h"
6 */
7
8#ifndef __S390_MMU_CONTEXT_H
9#define __S390_MMU_CONTEXT_H
10
11#include <asm/pgalloc.h>
12#include <linux/uaccess.h>
13#include <linux/mm_types.h>
14#include <asm/tlbflush.h>
15#include <asm/ctlreg.h>
16#include <asm/asce.h>
17#include <asm-generic/mm_hooks.h>
18
19#define init_new_context init_new_context
20static inline int init_new_context(struct task_struct *tsk,
21 struct mm_struct *mm)
22{
23 unsigned long asce_type, init_entry;
24
25 spin_lock_init(&mm->context.lock);
26 INIT_LIST_HEAD(&mm->context.gmap_list);
27 cpumask_clear(&mm->context.cpu_attach_mask);
28 atomic_set(&mm->context.flush_count, 0);
29 atomic_set(&mm->context.protected_count, 0);
30 mm->context.gmap_asce = 0;
31 mm->context.flush_mm = 0;
32#ifdef CONFIG_PGSTE
33 mm->context.has_pgste = 0;
34 mm->context.uses_skeys = 0;
35 mm->context.uses_cmm = 0;
36 mm->context.allow_cow_sharing = 1;
37 mm->context.allow_gmap_hpage_1m = 0;
38#endif
39 switch (mm->context.asce_limit) {
40 default:
41 /*
42 * context created by exec, the value of asce_limit can
43 * only be zero in this case
44 */
45 VM_BUG_ON(mm->context.asce_limit);
46 /* continue as 3-level task */
47 mm->context.asce_limit = _REGION2_SIZE;
48 fallthrough;
49 case _REGION2_SIZE:
50 /* forked 3-level task */
51 init_entry = _REGION3_ENTRY_EMPTY;
52 asce_type = _ASCE_TYPE_REGION3;
53 break;
54 case TASK_SIZE_MAX:
55 /* forked 5-level task */
56 init_entry = _REGION1_ENTRY_EMPTY;
57 asce_type = _ASCE_TYPE_REGION1;
58 break;
59 case _REGION1_SIZE:
60 /* forked 4-level task */
61 init_entry = _REGION2_ENTRY_EMPTY;
62 asce_type = _ASCE_TYPE_REGION2;
63 break;
64 }
65 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
66 _ASCE_USER_BITS | asce_type;
67 crst_table_init((unsigned long *) mm->pgd, init_entry);
68 return 0;
69}
70
71static inline void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
72 struct task_struct *tsk)
73{
74 int cpu = smp_processor_id();
75
76 if (next == &init_mm)
77 get_lowcore()->user_asce = s390_invalid_asce;
78 else
79 get_lowcore()->user_asce.val = next->context.asce;
80 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
81 /* Clear previous user-ASCE from CR1 and CR7 */
82 local_ctl_load(1, &s390_invalid_asce);
83 local_ctl_load(7, &s390_invalid_asce);
84 if (prev != next)
85 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
86}
87#define switch_mm_irqs_off switch_mm_irqs_off
88
89static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
90 struct task_struct *tsk)
91{
92 unsigned long flags;
93
94 local_irq_save(flags);
95 switch_mm_irqs_off(prev, next, tsk);
96 local_irq_restore(flags);
97}
98
99#define finish_arch_post_lock_switch finish_arch_post_lock_switch
100static inline void finish_arch_post_lock_switch(void)
101{
102 struct task_struct *tsk = current;
103 struct mm_struct *mm = tsk->mm;
104 unsigned long flags;
105
106 if (mm) {
107 preempt_disable();
108 while (atomic_read(&mm->context.flush_count))
109 cpu_relax();
110 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
111 __tlb_flush_mm_lazy(mm);
112 preempt_enable();
113 }
114 local_irq_save(flags);
115 if (test_thread_flag(TIF_ASCE_PRIMARY))
116 local_ctl_load(1, &get_lowcore()->kernel_asce);
117 else
118 local_ctl_load(1, &get_lowcore()->user_asce);
119 local_ctl_load(7, &get_lowcore()->user_asce);
120 local_irq_restore(flags);
121}
122
123#define activate_mm activate_mm
124static inline void activate_mm(struct mm_struct *prev,
125 struct mm_struct *next)
126{
127 switch_mm_irqs_off(prev, next, current);
128 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
129 if (test_thread_flag(TIF_ASCE_PRIMARY))
130 local_ctl_load(1, &get_lowcore()->kernel_asce);
131 else
132 local_ctl_load(1, &get_lowcore()->user_asce);
133 local_ctl_load(7, &get_lowcore()->user_asce);
134}
135
136#include <asm-generic/mmu_context.h>
137
138#endif /* __S390_MMU_CONTEXT_H */