aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-m32r/mmu_context.h
blob: 1f40d4a0acf1a4acd6d0a3764f5b9f09b9439a78 (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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
#ifndef _ASM_M32R_MMU_CONTEXT_H
#define _ASM_M32R_MMU_CONTEXT_H
#ifdef __KERNEL__

#include <asm/m32r.h>

#define MMU_CONTEXT_ASID_MASK      (0x000000FF)
#define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
#define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
#define NO_CONTEXT                 (0x00000000)

#ifndef __ASSEMBLY__

#include <asm/atomic.h>
#include <asm/pgalloc.h>
#include <asm/mmu.h>
#include <asm/tlbflush.h>

/*
 * Cache of MMU context last used.
 */
#ifndef CONFIG_SMP
extern unsigned long mmu_context_cache_dat;
#define mmu_context_cache	mmu_context_cache_dat
#define mm_context(mm)		mm->context
#else /* not CONFIG_SMP */
extern unsigned long mmu_context_cache_dat[];
#define mmu_context_cache	mmu_context_cache_dat[smp_processor_id()]
#define mm_context(mm)		mm->context[smp_processor_id()]
#endif /* not CONFIG_SMP */

#define set_tlb_tag(entry, tag)		(*entry = (tag & PAGE_MASK)|get_asid())
#define set_tlb_data(entry, data)	(*entry = (data | _PAGE_PRESENT))

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

static inline void get_new_mmu_context(struct mm_struct *mm)
{
	unsigned long mc = ++mmu_context_cache;

	if (!(mc & MMU_CONTEXT_ASID_MASK)) {
		/* We exhaust ASID of this version.
		   Flush all TLB and start new cycle. */
		local_flush_tlb_all();
		/* Fix version if needed.
		   Note that we avoid version #0 to distingush NO_CONTEXT. */
		if (!mc)
			mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
	}
	mm_context(mm) = mc;
}

/*
 * Get MMU context if needed.
 */
static inline void get_mmu_context(struct mm_struct *mm)
{
	if (mm) {
		unsigned long mc = mmu_context_cache;

		/* Check if we have old version of context.
		   If it's old, we need to get new context with new version. */
		if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
			get_new_mmu_context(mm);
	}
}

/*
 * Initialize the context related info for a new mm_struct
 * instance.
 */
static inline int init_new_context(struct task_struct *tsk,
	struct mm_struct *mm)
{
#ifndef CONFIG_SMP
	mm->context = NO_CONTEXT;
#else /* CONFIG_SMP */
	int num_cpus = num_online_cpus();
	int i;

	for (i = 0 ; i < num_cpus ; i++)
		mm->context[i] = NO_CONTEXT;
#endif /* CONFIG_SMP */

	return 0;
}

/*
 * Destroy context related info for an mm_struct that is about
 * to be put to rest.
 */
#define destroy_context(mm)	do { } while (0)

static inline void set_asid(unsigned long asid)
{
	*(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
}

static inline unsigned long get_asid(void)
{
	unsigned long asid;

	asid = *(volatile long *)MASID;
	asid &= MMU_CONTEXT_ASID_MASK;

	return asid;
}

/*
 * After we have set current->mm to a new value, this activates
 * the context for the new mm so we see the new mappings.
 */
static inline void activate_context(struct mm_struct *mm)
{
	get_mmu_context(mm);
	set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
}

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

	if (prev != next) {
#ifdef CONFIG_SMP
		cpu_set(cpu, next->cpu_vm_mask);
#endif /* CONFIG_SMP */
		/* Set MPTB = next->pgd */
		*(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
		activate_context(next);
	}
#ifdef CONFIG_SMP
	else
		if (!cpu_test_and_set(cpu, next->cpu_vm_mask))
			activate_context(next);
#endif /* CONFIG_SMP */
}

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

#define activate_mm(prev, next)	\
	switch_mm((prev), (next), NULL)

#else /* not CONFIG_MMU */
#define get_mmu_context(mm)             do { } while (0)
#define init_new_context(tsk,mm)        (0)
#define destroy_context(mm)             do { } while (0)
#define set_asid(asid)                  do { } while (0)
#define get_asid()                      (0)
#define activate_context(mm)            do { } while (0)
#define switch_mm(prev,next,tsk)        do { } while (0)
#define deactivate_mm(mm,tsk)           do { } while (0)
#define activate_mm(prev,next)          do { } while (0)
#define enter_lazy_tlb(mm,tsk)          do { } while (0)
#endif /* not CONFIG_MMU */

#endif /* not __ASSEMBLY__ */

#endif /* __KERNEL__ */
#endif /* _ASM_M32R_MMU_CONTEXT_H */