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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/ctl_reg.h>
16#include <asm-generic/mm_hooks.h>
17
18static inline int init_new_context(struct task_struct *tsk,
19 struct mm_struct *mm)
20{
21 unsigned long asce_type, init_entry;
22
23 spin_lock_init(&mm->context.lock);
24 INIT_LIST_HEAD(&mm->context.pgtable_list);
25 INIT_LIST_HEAD(&mm->context.gmap_list);
26 cpumask_clear(&mm->context.cpu_attach_mask);
27 atomic_set(&mm->context.flush_count, 0);
28 atomic_set(&mm->context.is_protected, 0);
29 mm->context.gmap_asce = 0;
30 mm->context.flush_mm = 0;
31#ifdef CONFIG_PGSTE
32 mm->context.alloc_pgste = page_table_allocate_pgste ||
33 test_thread_flag(TIF_PGSTE) ||
34 (current->mm && current->mm->context.alloc_pgste);
35 mm->context.has_pgste = 0;
36 mm->context.uses_skeys = 0;
37 mm->context.uses_cmm = 0;
38 mm->context.allow_gmap_hpage_1m = 0;
39#endif
40 switch (mm->context.asce_limit) {
41 default:
42 /*
43 * context created by exec, the value of asce_limit can
44 * only be zero in this case
45 */
46 VM_BUG_ON(mm->context.asce_limit);
47 /* continue as 3-level task */
48 mm->context.asce_limit = _REGION2_SIZE;
49 fallthrough;
50 case _REGION2_SIZE:
51 /* forked 3-level task */
52 init_entry = _REGION3_ENTRY_EMPTY;
53 asce_type = _ASCE_TYPE_REGION3;
54 break;
55 case TASK_SIZE_MAX:
56 /* forked 5-level task */
57 init_entry = _REGION1_ENTRY_EMPTY;
58 asce_type = _ASCE_TYPE_REGION1;
59 break;
60 case _REGION1_SIZE:
61 /* forked 4-level task */
62 init_entry = _REGION2_ENTRY_EMPTY;
63 asce_type = _ASCE_TYPE_REGION2;
64 break;
65 }
66 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
67 _ASCE_USER_BITS | asce_type;
68 crst_table_init((unsigned long *) mm->pgd, init_entry);
69 return 0;
70}
71
72#define destroy_context(mm) do { } while (0)
73
74static inline void set_user_asce(struct mm_struct *mm)
75{
76 S390_lowcore.user_asce = mm->context.asce;
77 __ctl_load(S390_lowcore.user_asce, 1, 1);
78 clear_cpu_flag(CIF_ASCE_PRIMARY);
79}
80
81static inline void clear_user_asce(void)
82{
83 S390_lowcore.user_asce = S390_lowcore.kernel_asce;
84 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
85 set_cpu_flag(CIF_ASCE_PRIMARY);
86}
87
88mm_segment_t enable_sacf_uaccess(void);
89void disable_sacf_uaccess(mm_segment_t old_fs);
90
91static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
92 struct task_struct *tsk)
93{
94 int cpu = smp_processor_id();
95
96 S390_lowcore.user_asce = next->context.asce;
97 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
98 /* Clear previous user-ASCE from CR1 and CR7 */
99 if (!test_cpu_flag(CIF_ASCE_PRIMARY)) {
100 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
101 set_cpu_flag(CIF_ASCE_PRIMARY);
102 }
103 if (test_cpu_flag(CIF_ASCE_SECONDARY)) {
104 __ctl_load(S390_lowcore.vdso_asce, 7, 7);
105 clear_cpu_flag(CIF_ASCE_SECONDARY);
106 }
107 if (prev != next)
108 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
109}
110
111#define finish_arch_post_lock_switch finish_arch_post_lock_switch
112static inline void finish_arch_post_lock_switch(void)
113{
114 struct task_struct *tsk = current;
115 struct mm_struct *mm = tsk->mm;
116
117 if (mm) {
118 preempt_disable();
119 while (atomic_read(&mm->context.flush_count))
120 cpu_relax();
121 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
122 __tlb_flush_mm_lazy(mm);
123 preempt_enable();
124 }
125 set_fs(current->thread.mm_segment);
126}
127
128#define enter_lazy_tlb(mm,tsk) do { } while (0)
129#define deactivate_mm(tsk,mm) do { } while (0)
130
131static inline void activate_mm(struct mm_struct *prev,
132 struct mm_struct *next)
133{
134 switch_mm(prev, next, current);
135 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
136 set_user_asce(next);
137}
138
139#endif /* __S390_MMU_CONTEXT_H */