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