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
init_new_context(struct task_struct * tsk,struct mm_struct * mm)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 && current->mm->context.alloc_pgste);
32 mm->context.has_pgste = 0;
33 mm->context.uses_skeys = 0;
34 mm->context.uses_cmm = 0;
35 mm->context.allow_gmap_hpage_1m = 0;
36 #endif
37 switch (mm->context.asce_limit) {
38 case _REGION2_SIZE:
39 /*
40 * forked 3-level task, fall through to set new asce with new
41 * mm->pgd
42 */
43 case 0:
44 /* context created by exec, set asce limit to 4TB */
45 mm->context.asce_limit = STACK_TOP_MAX;
46 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
47 _ASCE_USER_BITS | _ASCE_TYPE_REGION3;
48 /* pgd_alloc() did not account this pud */
49 mm_inc_nr_puds(mm);
50 break;
51 case -PAGE_SIZE:
52 /* forked 5-level task, set new asce with new_mm->pgd */
53 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
54 _ASCE_USER_BITS | _ASCE_TYPE_REGION1;
55 break;
56 case _REGION1_SIZE:
57 /* forked 4-level task, set new asce with new mm->pgd */
58 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
59 _ASCE_USER_BITS | _ASCE_TYPE_REGION2;
60 break;
61 case _REGION3_SIZE:
62 /* forked 2-level compat task, set new asce with new mm->pgd */
63 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
64 _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT;
65 /* pgd_alloc() did not account this pmd */
66 mm_inc_nr_pmds(mm);
67 mm_inc_nr_puds(mm);
68 }
69 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
70 return 0;
71 }
72
73 #define destroy_context(mm) do { } while (0)
74
set_user_asce(struct mm_struct * mm)75 static inline void set_user_asce(struct mm_struct *mm)
76 {
77 S390_lowcore.user_asce = mm->context.asce;
78 __ctl_load(S390_lowcore.user_asce, 1, 1);
79 clear_cpu_flag(CIF_ASCE_PRIMARY);
80 }
81
clear_user_asce(void)82 static inline void clear_user_asce(void)
83 {
84 S390_lowcore.user_asce = S390_lowcore.kernel_asce;
85 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
86 set_cpu_flag(CIF_ASCE_PRIMARY);
87 }
88
89 mm_segment_t enable_sacf_uaccess(void);
90 void disable_sacf_uaccess(mm_segment_t old_fs);
91
switch_mm(struct mm_struct * prev,struct mm_struct * next,struct task_struct * tsk)92 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
93 struct task_struct *tsk)
94 {
95 int cpu = smp_processor_id();
96
97 if (prev == next)
98 return;
99 S390_lowcore.user_asce = next->context.asce;
100 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
101 /* Clear previous user-ASCE from CR1 and CR7 */
102 if (!test_cpu_flag(CIF_ASCE_PRIMARY)) {
103 __ctl_load(S390_lowcore.kernel_asce, 1, 1);
104 set_cpu_flag(CIF_ASCE_PRIMARY);
105 }
106 if (test_cpu_flag(CIF_ASCE_SECONDARY)) {
107 __ctl_load(S390_lowcore.vdso_asce, 7, 7);
108 clear_cpu_flag(CIF_ASCE_SECONDARY);
109 }
110 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
111 }
112
113 #define finish_arch_post_lock_switch finish_arch_post_lock_switch
finish_arch_post_lock_switch(void)114 static inline void finish_arch_post_lock_switch(void)
115 {
116 struct task_struct *tsk = current;
117 struct mm_struct *mm = tsk->mm;
118
119 if (mm) {
120 preempt_disable();
121 while (atomic_read(&mm->context.flush_count))
122 cpu_relax();
123 cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
124 __tlb_flush_mm_lazy(mm);
125 preempt_enable();
126 }
127 set_fs(current->thread.mm_segment);
128 }
129
130 #define enter_lazy_tlb(mm,tsk) do { } while (0)
131 #define deactivate_mm(tsk,mm) do { } while (0)
132
activate_mm(struct mm_struct * prev,struct mm_struct * next)133 static inline void activate_mm(struct mm_struct *prev,
134 struct mm_struct *next)
135 {
136 switch_mm(prev, next, current);
137 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
138 set_user_asce(next);
139 }
140
141 #endif /* __S390_MMU_CONTEXT_H */
142
