Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
[sfrench/cifs-2.6.git] / arch / s390 / include / asm / mmu_context.h
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
18 static inline int init_new_context(struct task_struct *tsk,
19                                    struct mm_struct *mm)
20 {
21         spin_lock_init(&mm->context.lock);
22         INIT_LIST_HEAD(&mm->context.pgtable_list);
23         INIT_LIST_HEAD(&mm->context.gmap_list);
24         cpumask_clear(&mm->context.cpu_attach_mask);
25         atomic_set(&mm->context.flush_count, 0);
26         mm->context.gmap_asce = 0;
27         mm->context.flush_mm = 0;
28 #ifdef CONFIG_PGSTE
29         mm->context.alloc_pgste = page_table_allocate_pgste ||
30                 test_thread_flag(TIF_PGSTE) ||
31                 current->mm->context.alloc_pgste;
32         mm->context.has_pgste = 0;
33         mm->context.use_skey = 0;
34         mm->context.use_cmma = 0;
35 #endif
36         switch (mm->context.asce_limit) {
37         case _REGION2_SIZE:
38                 /*
39                  * forked 3-level task, fall through to set new asce with new
40                  * mm->pgd
41                  */
42         case 0:
43                 /* context created by exec, set asce limit to 4TB */
44                 mm->context.asce_limit = STACK_TOP_MAX;
45                 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
46                                    _ASCE_USER_BITS | _ASCE_TYPE_REGION3;
47                 /* pgd_alloc() did not account this pud */
48                 mm_inc_nr_puds(mm);
49                 break;
50         case -PAGE_SIZE:
51                 /* forked 5-level task, set new asce with new_mm->pgd */
52                 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
53                         _ASCE_USER_BITS | _ASCE_TYPE_REGION1;
54                 break;
55         case _REGION1_SIZE:
56                 /* forked 4-level task, set new asce with new mm->pgd */
57                 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
58                                    _ASCE_USER_BITS | _ASCE_TYPE_REGION2;
59                 break;
60         case _REGION3_SIZE:
61                 /* forked 2-level compat task, set new asce with new mm->pgd */
62                 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
63                                    _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT;
64                 /* pgd_alloc() did not account this pmd */
65                 mm_inc_nr_pmds(mm);
66         }
67         crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
68         return 0;
69 }
70
71 #define destroy_context(mm)             do { } while (0)
72
73 static inline void set_user_asce(struct mm_struct *mm)
74 {
75         S390_lowcore.user_asce = mm->context.asce;
76         __ctl_load(S390_lowcore.user_asce, 1, 1);
77         clear_cpu_flag(CIF_ASCE_PRIMARY);
78 }
79
80 static inline void clear_user_asce(void)
81 {
82         S390_lowcore.user_asce = S390_lowcore.kernel_asce;
83         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
84         set_cpu_flag(CIF_ASCE_PRIMARY);
85 }
86
87 mm_segment_t enable_sacf_uaccess(void);
88 void disable_sacf_uaccess(mm_segment_t old_fs);
89
90 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
91                              struct task_struct *tsk)
92 {
93         int cpu = smp_processor_id();
94
95         if (prev == next)
96                 return;
97         S390_lowcore.user_asce = next->context.asce;
98         cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
99         /* Clear previous user-ASCE from CR1 and CR7 */
100         if (!test_cpu_flag(CIF_ASCE_PRIMARY)) {
101                 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
102                 set_cpu_flag(CIF_ASCE_PRIMARY);
103         }
104         if (test_cpu_flag(CIF_ASCE_SECONDARY)) {
105                 __ctl_load(S390_lowcore.vdso_asce, 7, 7);
106                 clear_cpu_flag(CIF_ASCE_SECONDARY);
107         }
108         cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
109 }
110
111 #define finish_arch_post_lock_switch finish_arch_post_lock_switch
112 static 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
131 static 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 */