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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
18#define init_new_context init_new_context
19static inline int init_new_context(struct task_struct *tsk,
20 struct mm_struct *mm)
21{
22 unsigned long asce_type, init_entry;
23
24 spin_lock_init(&mm->context.lock);
25 INIT_LIST_HEAD(&mm->context.pgtable_list);
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.alloc_pgste = page_table_allocate_pgste ||
34 test_thread_flag(TIF_PGSTE) ||
35 (current->mm && current->mm->context.alloc_pgste);
36 mm->context.has_pgste = 0;
37 mm->context.uses_skeys = 0;
38 mm->context.uses_cmm = 0;
39 mm->context.allow_gmap_hpage_1m = 0;
40#endif
41 switch (mm->context.asce_limit) {
42 default:
43 /*
44 * context created by exec, the value of asce_limit can
45 * only be zero in this case
46 */
47 VM_BUG_ON(mm->context.asce_limit);
48 /* continue as 3-level task */
49 mm->context.asce_limit = _REGION2_SIZE;
50 fallthrough;
51 case _REGION2_SIZE:
52 /* forked 3-level task */
53 init_entry = _REGION3_ENTRY_EMPTY;
54 asce_type = _ASCE_TYPE_REGION3;
55 break;
56 case TASK_SIZE_MAX:
57 /* forked 5-level task */
58 init_entry = _REGION1_ENTRY_EMPTY;
59 asce_type = _ASCE_TYPE_REGION1;
60 break;
61 case _REGION1_SIZE:
62 /* forked 4-level task */
63 init_entry = _REGION2_ENTRY_EMPTY;
64 asce_type = _ASCE_TYPE_REGION2;
65 break;
66 }
67 mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
68 _ASCE_USER_BITS | asce_type;
69 crst_table_init((unsigned long *) mm->pgd, init_entry);
70 return 0;
71}
72
73static inline void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
74 struct task_struct *tsk)
75{
76 int cpu = smp_processor_id();
77
78 if (next == &init_mm)
79 S390_lowcore.user_asce = s390_invalid_asce;
80 else
81 S390_lowcore.user_asce = next->context.asce;
82 cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
83 /* Clear previous user-ASCE from CR7 */
84 __ctl_load(s390_invalid_asce, 7, 7);
85 if (prev != next)
86 cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
87}
88#define switch_mm_irqs_off switch_mm_irqs_off
89
90static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
91 struct task_struct *tsk)
92{
93 unsigned long flags;
94
95 local_irq_save(flags);
96 switch_mm_irqs_off(prev, next, tsk);
97 local_irq_restore(flags);
98}
99
100#define finish_arch_post_lock_switch finish_arch_post_lock_switch
101static inline void finish_arch_post_lock_switch(void)
102{
103 struct task_struct *tsk = current;
104 struct mm_struct *mm = tsk->mm;
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 __ctl_load(S390_lowcore.user_asce, 7, 7);
115}
116
117#define activate_mm activate_mm
118static inline void activate_mm(struct mm_struct *prev,
119 struct mm_struct *next)
120{
121 switch_mm(prev, next, current);
122 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
123 __ctl_load(S390_lowcore.user_asce, 7, 7);
124}
125
126#include <asm-generic/mmu_context.h>
127
128#endif /* __S390_MMU_CONTEXT_H */
1/*
2 * include/asm-s390/mmu_context.h
3 *
4 * S390 version
5 *
6 * Derived from "include/asm-i386/mmu_context.h"
7 */
8
9#ifndef __S390_MMU_CONTEXT_H
10#define __S390_MMU_CONTEXT_H
11
12#include <asm/pgalloc.h>
13#include <asm/uaccess.h>
14#include <asm/tlbflush.h>
15#include <asm-generic/mm_hooks.h>
16
17static inline int init_new_context(struct task_struct *tsk,
18 struct mm_struct *mm)
19{
20 atomic_set(&mm->context.attach_count, 0);
21 mm->context.flush_mm = 0;
22 mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
23#ifdef CONFIG_64BIT
24 mm->context.asce_bits |= _ASCE_TYPE_REGION3;
25#endif
26 if (current->mm && current->mm->context.alloc_pgste) {
27 /*
28 * alloc_pgste indicates, that any NEW context will be created
29 * with extended page tables. The old context is unchanged. The
30 * page table allocation and the page table operations will
31 * look at has_pgste to distinguish normal and extended page
32 * tables. The only way to create extended page tables is to
33 * set alloc_pgste and then create a new context (e.g. dup_mm).
34 * The page table allocation is called after init_new_context
35 * and if has_pgste is set, it will create extended page
36 * tables.
37 */
38 mm->context.has_pgste = 1;
39 mm->context.alloc_pgste = 1;
40 } else {
41 mm->context.has_pgste = 0;
42 mm->context.alloc_pgste = 0;
43 }
44 mm->context.asce_limit = STACK_TOP_MAX;
45 crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
46 return 0;
47}
48
49#define destroy_context(mm) do { } while (0)
50
51#ifndef __s390x__
52#define LCTL_OPCODE "lctl"
53#else
54#define LCTL_OPCODE "lctlg"
55#endif
56
57static inline void update_mm(struct mm_struct *mm, struct task_struct *tsk)
58{
59 pgd_t *pgd = mm->pgd;
60
61 S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);
62 if (user_mode != HOME_SPACE_MODE) {
63 /* Load primary space page table origin. */
64 asm volatile(LCTL_OPCODE" 1,1,%0\n"
65 : : "m" (S390_lowcore.user_asce) );
66 } else
67 /* Load home space page table origin. */
68 asm volatile(LCTL_OPCODE" 13,13,%0"
69 : : "m" (S390_lowcore.user_asce) );
70 set_fs(current->thread.mm_segment);
71}
72
73static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
74 struct task_struct *tsk)
75{
76 cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
77 update_mm(next, tsk);
78 atomic_dec(&prev->context.attach_count);
79 WARN_ON(atomic_read(&prev->context.attach_count) < 0);
80 atomic_inc(&next->context.attach_count);
81 /* Check for TLBs not flushed yet */
82 if (next->context.flush_mm)
83 __tlb_flush_mm(next);
84}
85
86#define enter_lazy_tlb(mm,tsk) do { } while (0)
87#define deactivate_mm(tsk,mm) do { } while (0)
88
89static inline void activate_mm(struct mm_struct *prev,
90 struct mm_struct *next)
91{
92 switch_mm(prev, next, current);
93}
94
95#endif /* __S390_MMU_CONTEXT_H */