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
|
/*
* Copyright (C) 1999 Niibe Yutaka
*
* ASID handling idea taken from MIPS implementation.
*/
#ifndef __ASM_SH_MMU_CONTEXT_H
#define __ASM_SH_MMU_CONTEXT_H
/* The MMU "context" consists of two things:
(a) TLB cache version (or round, cycle whatever expression you like)
(b) ASID (Address Space IDentifier)
*/
/*
* Cache of MMU context last used.
*/
extern unsigned long mmu_context_cache;
#define MMU_CONTEXT_ASID_MASK 0xff
#define MMU_CONTEXT_VERSION_MASK 0xffffff00
#define MMU_CONTEXT_FIRST_VERSION 0x100
#define NO_CONTEXT 0
extern __inline__ void
get_new_mmu_context(struct mm_struct *mm)
{
extern void flush_tlb_all(void);
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. */
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 = mc;
}
/*
* Get MMU context if needed.
*/
extern __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 ^ mc) & MMU_CONTEXT_VERSION_MASK)
get_new_mmu_context(mm);
}
}
/*
* Initialize the context related info for a new mm_struct
* instance.
*/
extern __inline__ void init_new_context(struct task_struct *tsk,
struct mm_struct *mm)
{
mm->context = NO_CONTEXT;
}
/*
* Destroy context related info for an mm_struct that is about
* to be put to rest.
*/
extern __inline__ void destroy_context(struct mm_struct *mm)
{
mm->context = NO_CONTEXT;
}
/* Other MMU related constants. */
#if defined(__sh3__)
#define MMU_PTEH 0xFFFFFFF0 /* Page table entry register HIGH */
#define MMU_PTEL 0xFFFFFFF4 /* Page table entry register LOW */
#define MMU_TTB 0xFFFFFFF8 /* Translation table base register */
#define MMU_TEA 0xFFFFFFFC /* TLB Exception Address */
#define MMUCR 0xFFFFFFE0 /* MMU Control Register */
#define MMU_TLB_ADDRESS_ARRAY 0xF2000000
#define MMU_PAGE_ASSOC_BIT 0x80
#define MMU_NTLB_ENTRIES 128 /* for 7708 */
#define MMU_CONTROL_INIT 0x007 /* SV=0, TF=1, IX=1, AT=1 */
#elif defined(__SH4__)
#define MMU_PTEH 0xFF000000 /* Page table entry register HIGH */
#define MMU_PTEL 0xFF000004 /* Page table entry register LOW */
#define MMU_TTB 0xFF000008 /* Translation table base register */
#define MMU_TEA 0xFF00000C /* TLB Exception Address */
#define MMUCR 0xFF000010 /* MMU Control Register */
#define MMU_ITLB_ADDRESS_ARRAY 0xF2000000
#define MMU_UTLB_ADDRESS_ARRAY 0xF6000000
#define MMU_PAGE_ASSOC_BIT 0x80
#define MMU_NTLB_ENTRIES 64 /* for 7750 */
#define MMU_CONTROL_INIT 0x205 /* SQMD=1, SV=0, TI=1, AT=1 */
#endif
extern __inline__ void set_asid (unsigned long asid)
{
__asm__ __volatile__ ("mov.l %0,%1"
: /* no output */
: "r" (asid), "m" (__m(MMU_PTEH)));
}
extern __inline__ unsigned long get_asid (void)
{
unsigned long asid;
__asm__ __volatile__ ("mov.l %1,%0"
: "=r" (asid)
: "m" (__m(MMU_PTEH)));
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.
*/
extern __inline__ void activate_context(struct mm_struct *mm)
{
get_mmu_context(mm);
set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
}
/* MMU_TTB can be used for optimizing the fault handling.
(Currently not used) */
extern __inline__ void switch_mm(struct mm_struct *prev,
struct mm_struct *next,
struct task_struct *tsk, unsigned int cpu)
{
if (prev != next) {
unsigned long __pgdir = (unsigned long)next->pgd;
__asm__ __volatile__("mov.l %0,%1": \
:"r" (__pgdir), "m" (__m(MMU_TTB)));
activate_context(next);
clear_bit(cpu, &prev->cpu_vm_mask);
}
set_bit(cpu, &next->cpu_vm_mask);
}
#define activate_mm(prev, next) \
switch_mm((prev),(next),NULL,smp_processor_id())
#endif /* __ASM_SH_MMU_CONTEXT_H */
|
