aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/include/asm/mmu_context.h
blob: 65154eaa3714a4e9182cb87654e7b896e7be3e2f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  S390 version
 *
 *  Derived from "include/asm-i386/mmu_context.h"
 */

#ifndef __S390_MMU_CONTEXT_H
#define __S390_MMU_CONTEXT_H

#include <asm/pgalloc.h>
#include <linux/uaccess.h>
#include <linux/mm_types.h>
#include <asm/tlbflush.h>
#include <asm/ctl_reg.h>
#include <asm-generic/mm_hooks.h>

static inline int init_new_context(struct task_struct *tsk,
				   struct mm_struct *mm)
{
	spin_lock_init(&mm->context.lock);
	INIT_LIST_HEAD(&mm->context.pgtable_list);
	INIT_LIST_HEAD(&mm->context.gmap_list);
	cpumask_clear(&mm->context.cpu_attach_mask);
	atomic_set(&mm->context.flush_count, 0);
	mm->context.gmap_asce = 0;
	mm->context.flush_mm = 0;
#ifdef CONFIG_PGSTE
	mm->context.alloc_pgste = page_table_allocate_pgste ||
		test_thread_flag(TIF_PGSTE) ||
		(current->mm && current->mm->context.alloc_pgste);
	mm->context.has_pgste = 0;
	mm->context.use_skey = 0;
	mm->context.use_cmma = 0;
#endif
	switch (mm->context.asce_limit) {
	case _REGION2_SIZE:
		/*
		 * forked 3-level task, fall through to set new asce with new
		 * mm->pgd
		 */
	case 0:
		/* context created by exec, set asce limit to 4TB */
		mm->context.asce_limit = STACK_TOP_MAX;
		mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
				   _ASCE_USER_BITS | _ASCE_TYPE_REGION3;
		/* pgd_alloc() did not account this pud */
		mm_inc_nr_puds(mm);
		break;
	case -PAGE_SIZE:
		/* forked 5-level task, set new asce with new_mm->pgd */
		mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
			_ASCE_USER_BITS | _ASCE_TYPE_REGION1;
		break;
	case _REGION1_SIZE:
		/* forked 4-level task, set new asce with new mm->pgd */
		mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
				   _ASCE_USER_BITS | _ASCE_TYPE_REGION2;
		break;
	case _REGION3_SIZE:
		/* forked 2-level compat task, set new asce with new mm->pgd */
		mm->context.asce = __pa(mm->pgd) | _ASCE_TABLE_LENGTH |
				   _ASCE_USER_BITS | _ASCE_TYPE_SEGMENT;
		/* pgd_alloc() did not account this pmd */
		mm_inc_nr_pmds(mm);
	}
	crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
	return 0;
}

#define destroy_context(mm)             do { } while (0)

static inline void set_user_asce(struct mm_struct *mm)
{
	S390_lowcore.user_asce = mm->context.asce;
	__ctl_load(S390_lowcore.user_asce, 1, 1);
	clear_cpu_flag(CIF_ASCE_PRIMARY);
}

static inline void clear_user_asce(void)
{
	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
	__ctl_load(S390_lowcore.kernel_asce, 1, 1);
	set_cpu_flag(CIF_ASCE_PRIMARY);
}

mm_segment_t enable_sacf_uaccess(void);
void disable_sacf_uaccess(mm_segment_t old_fs);

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
			     struct task_struct *tsk)
{
	int cpu = smp_processor_id();

	if (prev == next)
		return;
	S390_lowcore.user_asce = next->context.asce;
	cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
	/* Clear previous user-ASCE from CR1 and CR7 */
	if (!test_cpu_flag(CIF_ASCE_PRIMARY)) {
		__ctl_load(S390_lowcore.kernel_asce, 1, 1);
		set_cpu_flag(CIF_ASCE_PRIMARY);
	}
	if (test_cpu_flag(CIF_ASCE_SECONDARY)) {
		__ctl_load(S390_lowcore.vdso_asce, 7, 7);
		clear_cpu_flag(CIF_ASCE_SECONDARY);
	}
	cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
}

#define finish_arch_post_lock_switch finish_arch_post_lock_switch
static inline void finish_arch_post_lock_switch(void)
{
	struct task_struct *tsk = current;
	struct mm_struct *mm = tsk->mm;

	if (mm) {
		preempt_disable();
		while (atomic_read(&mm->context.flush_count))
			cpu_relax();
		cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
		__tlb_flush_mm_lazy(mm);
		preempt_enable();
	}
	set_fs(current->thread.mm_segment);
}

#define enter_lazy_tlb(mm,tsk)	do { } while (0)
#define deactivate_mm(tsk,mm)	do { } while (0)

static inline void activate_mm(struct mm_struct *prev,
                               struct mm_struct *next)
{
	switch_mm(prev, next, current);
	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
	set_user_asce(next);
}

#endif /* __S390_MMU_CONTEXT_H */