1 #ifndef _ASM_M32R_MMU_CONTEXT_H
2 #define _ASM_M32R_MMU_CONTEXT_H
3 #ifdef __KERNEL__
4
5 #include <asm/m32r.h>
6
7 #define MMU_CONTEXT_ASID_MASK (0x000000FF)
8 #define MMU_CONTEXT_VERSION_MASK (0xFFFFFF00)
9 #define MMU_CONTEXT_FIRST_VERSION (0x00000100)
10 #define NO_CONTEXT (0x00000000)
11
12 #ifndef __ASSEMBLY__
13
14 #include <linux/atomic.h>
15 #include <asm/pgalloc.h>
16 #include <asm/mmu.h>
17 #include <asm/tlbflush.h>
18 #include <asm-generic/mm_hooks.h>
19
20 /*
21 * Cache of MMU context last used.
22 */
23 #ifndef CONFIG_SMP
24 extern unsigned long mmu_context_cache_dat;
25 #define mmu_context_cache mmu_context_cache_dat
26 #define mm_context(mm) mm->context
27 #else /* not CONFIG_SMP */
28 extern unsigned long mmu_context_cache_dat[];
29 #define mmu_context_cache mmu_context_cache_dat[smp_processor_id()]
30 #define mm_context(mm) mm->context[smp_processor_id()]
31 #endif /* not CONFIG_SMP */
32
33 #define set_tlb_tag(entry, tag) (*entry = (tag & PAGE_MASK)|get_asid())
34 #define set_tlb_data(entry, data) (*entry = (data | _PAGE_PRESENT))
35
36 #ifdef CONFIG_MMU
37 #define enter_lazy_tlb(mm, tsk) do { } while (0)
38
39 static inline void get_new_mmu_context(struct mm_struct *mm)
40 {
41 unsigned long mc = ++mmu_context_cache;
42
43 if (!(mc & MMU_CONTEXT_ASID_MASK)) {
44 /* We exhaust ASID of this version.
45 Flush all TLB and start new cycle. */
46 local_flush_tlb_all();
47 /* Fix version if needed.
48 Note that we avoid version #0 to distinguish NO_CONTEXT. */
49 if (!mc)
50 mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
51 }
52 mm_context(mm) = mc;
53 }
54
55 /*
56 * Get MMU context if needed.
57 */
58 static inline void get_mmu_context(struct mm_struct *mm)
59 {
60 if (mm) {
61 unsigned long mc = mmu_context_cache;
62
63 /* Check if we have old version of context.
64 If it's old, we need to get new context with new version. */
65 if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
66 get_new_mmu_context(mm);
67 }
68 }
69
70 /*
71 * Initialize the context related info for a new mm_struct
72 * instance.
73 */
74 static inline int init_new_context(struct task_struct *tsk,
75 struct mm_struct *mm)
76 {
77 #ifndef CONFIG_SMP
78 mm->context = NO_CONTEXT;
79 #else /* CONFIG_SMP */
80 int num_cpus = num_online_cpus();
81 int i;
82
83 for (i = 0 ; i < num_cpus ; i++)
84 mm->context[i] = NO_CONTEXT;
85 #endif /* CONFIG_SMP */
86
87 return 0;
88 }
89
90 /*
91 * Destroy context related info for an mm_struct that is about
92 * to be put to rest.
93 */
94 #define destroy_context(mm) do { } while (0)
95
96 static inline void set_asid(unsigned long asid)
97 {
98 *(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
99 }
100
101 static inline unsigned long get_asid(void)
102 {
103 unsigned long asid;
104
105 asid = *(volatile long *)MASID;
106 asid &= MMU_CONTEXT_ASID_MASK;
107
108 return asid;
109 }
110
111 /*
112 * After we have set current->mm to a new value, this activates
113 * the context for the new mm so we see the new mappings.
114 */
115 static inline void activate_context(struct mm_struct *mm)
116 {
117 get_mmu_context(mm);
118 set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
119 }
120
121 static inline void switch_mm(struct mm_struct *prev,
122 struct mm_struct *next, struct task_struct *tsk)
123 {
124 #ifdef CONFIG_SMP
125 int cpu = smp_processor_id();
126 #endif /* CONFIG_SMP */
127
128 if (prev != next) {
129 #ifdef CONFIG_SMP
130 cpumask_set_cpu(cpu, mm_cpumask(next));
131 #endif /* CONFIG_SMP */
132 /* Set MPTB = next->pgd */
133 *(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
134 activate_context(next);
135 }
136 #ifdef CONFIG_SMP
137 else
138 if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)))
139 activate_context(next);
140 #endif /* CONFIG_SMP */
141 }
142
143 #define deactivate_mm(tsk, mm) do { } while (0)
144
145 #define activate_mm(prev, next) \
146 switch_mm((prev), (next), NULL)
147
148 #else /* not CONFIG_MMU */
149 #define get_mmu_context(mm) do { } while (0)
150 #define init_new_context(tsk,mm) (0)
151 #define destroy_context(mm) do { } while (0)
152 #define set_asid(asid) do { } while (0)
153 #define get_asid() (0)
154 #define activate_context(mm) do { } while (0)
155 #define switch_mm(prev,next,tsk) do { } while (0)
156 #define deactivate_mm(mm,tsk) do { } while (0)
157 #define activate_mm(prev,next) do { } while (0)
158 #define enter_lazy_tlb(mm,tsk) do { } while (0)
159 #endif /* not CONFIG_MMU */
160
161 #endif /* not __ASSEMBLY__ */
162
163 #endif /* __KERNEL__ */
164 #endif /* _ASM_M32R_MMU_CONTEXT_H */
165
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