Commit | Line | Data |
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1da177e4 | 1 | /* |
4baa9922 | 2 | * arch/arm/include/asm/mmu_context.h |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 1996 Russell King. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 as | |
8 | * published by the Free Software Foundation. | |
9 | * | |
10 | * Changelog: | |
11 | * 27-06-1996 RMK Created | |
12 | */ | |
13 | #ifndef __ASM_ARM_MMU_CONTEXT_H | |
14 | #define __ASM_ARM_MMU_CONTEXT_H | |
15 | ||
8dc39b88 | 16 | #include <linux/compiler.h> |
87c52578 | 17 | #include <linux/sched.h> |
4fe15ba0 | 18 | #include <asm/cacheflush.h> |
46097c7d | 19 | #include <asm/cachetype.h> |
1da177e4 LT |
20 | #include <asm/proc-fns.h> |
21 | ||
ff0daca5 RK |
22 | void __check_kvm_seq(struct mm_struct *mm); |
23 | ||
516793c6 | 24 | #ifdef CONFIG_CPU_HAS_ASID |
1da177e4 LT |
25 | |
26 | /* | |
27 | * On ARMv6, we have the following structure in the Context ID: | |
28 | * | |
29 | * 31 7 0 | |
30 | * +-------------------------+-----------+ | |
31 | * | process ID | ASID | | |
32 | * +-------------------------+-----------+ | |
33 | * | context ID | | |
34 | * +-------------------------------------+ | |
35 | * | |
36 | * The ASID is used to tag entries in the CPU caches and TLBs. | |
37 | * The context ID is used by debuggers and trace logic, and | |
38 | * should be unique within all running processes. | |
39 | */ | |
8678c1f0 RK |
40 | #define ASID_BITS 8 |
41 | #define ASID_MASK ((~0) << ASID_BITS) | |
42 | #define ASID_FIRST_VERSION (1 << ASID_BITS) | |
1da177e4 LT |
43 | |
44 | extern unsigned int cpu_last_asid; | |
11805bcf CM |
45 | #ifdef CONFIG_SMP |
46 | DECLARE_PER_CPU(struct mm_struct *, current_mm); | |
47 | #endif | |
1da177e4 LT |
48 | |
49 | void __init_new_context(struct task_struct *tsk, struct mm_struct *mm); | |
50 | void __new_context(struct mm_struct *mm); | |
51 | ||
52 | static inline void check_context(struct mm_struct *mm) | |
53 | { | |
11805bcf CM |
54 | /* |
55 | * This code is executed with interrupts enabled. Therefore, | |
56 | * mm->context.id cannot be updated to the latest ASID version | |
57 | * on a different CPU (and condition below not triggered) | |
58 | * without first getting an IPI to reset the context. The | |
59 | * alternative is to take a read_lock on mm->context.id_lock | |
60 | * (after changing its type to rwlock_t). | |
61 | */ | |
1da177e4 LT |
62 | if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS)) |
63 | __new_context(mm); | |
ff0daca5 RK |
64 | |
65 | if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq)) | |
66 | __check_kvm_seq(mm); | |
1da177e4 LT |
67 | } |
68 | ||
69 | #define init_new_context(tsk,mm) (__init_new_context(tsk,mm),0) | |
70 | ||
71 | #else | |
72 | ||
ff0daca5 RK |
73 | static inline void check_context(struct mm_struct *mm) |
74 | { | |
9a45f026 | 75 | #ifdef CONFIG_MMU |
ff0daca5 RK |
76 | if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq)) |
77 | __check_kvm_seq(mm); | |
9a45f026 | 78 | #endif |
ff0daca5 RK |
79 | } |
80 | ||
1da177e4 LT |
81 | #define init_new_context(tsk,mm) 0 |
82 | ||
83 | #endif | |
84 | ||
85 | #define destroy_context(mm) do { } while(0) | |
86 | ||
87 | /* | |
88 | * This is called when "tsk" is about to enter lazy TLB mode. | |
89 | * | |
90 | * mm: describes the currently active mm context | |
91 | * tsk: task which is entering lazy tlb | |
92 | * cpu: cpu number which is entering lazy tlb | |
93 | * | |
94 | * tsk->mm will be NULL | |
95 | */ | |
96 | static inline void | |
97 | enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) | |
98 | { | |
99 | } | |
100 | ||
101 | /* | |
102 | * This is the actual mm switch as far as the scheduler | |
103 | * is concerned. No registers are touched. We avoid | |
104 | * calling the CPU specific function when the mm hasn't | |
105 | * actually changed. | |
106 | */ | |
107 | static inline void | |
108 | switch_mm(struct mm_struct *prev, struct mm_struct *next, | |
109 | struct task_struct *tsk) | |
110 | { | |
002547b4 | 111 | #ifdef CONFIG_MMU |
1da177e4 LT |
112 | unsigned int cpu = smp_processor_id(); |
113 | ||
826cbdaf CM |
114 | #ifdef CONFIG_SMP |
115 | /* check for possible thread migration */ | |
56f8ba83 RR |
116 | if (!cpumask_empty(mm_cpumask(next)) && |
117 | !cpumask_test_cpu(cpu, mm_cpumask(next))) | |
826cbdaf CM |
118 | __flush_icache_all(); |
119 | #endif | |
56f8ba83 | 120 | if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) { |
11805bcf CM |
121 | #ifdef CONFIG_SMP |
122 | struct mm_struct **crt_mm = &per_cpu(current_mm, cpu); | |
123 | *crt_mm = next; | |
124 | #endif | |
1da177e4 LT |
125 | check_context(next); |
126 | cpu_switch_mm(next->pgd, next); | |
7e5e6e9a | 127 | if (cache_is_vivt()) |
56f8ba83 | 128 | cpumask_clear_cpu(cpu, mm_cpumask(prev)); |
1da177e4 | 129 | } |
002547b4 | 130 | #endif |
1da177e4 LT |
131 | } |
132 | ||
133 | #define deactivate_mm(tsk,mm) do { } while (0) | |
134 | #define activate_mm(prev,next) switch_mm(prev, next, NULL) | |
135 | ||
ec706dab NP |
136 | /* |
137 | * We are inserting a "fake" vma for the user-accessible vector page so | |
138 | * gdb and friends can get to it through ptrace and /proc/<pid>/mem. | |
139 | * But we also want to remove it before the generic code gets to see it | |
140 | * during process exit or the unmapping of it would cause total havoc. | |
141 | * (the macro is used as remove_vma() is static to mm/mmap.c) | |
142 | */ | |
143 | #define arch_exit_mmap(mm) \ | |
144 | do { \ | |
145 | struct vm_area_struct *high_vma = find_vma(mm, 0xffff0000); \ | |
146 | if (high_vma) { \ | |
147 | BUG_ON(high_vma->vm_next); /* it should be last */ \ | |
148 | if (high_vma->vm_prev) \ | |
149 | high_vma->vm_prev->vm_next = NULL; \ | |
150 | else \ | |
151 | mm->mmap = NULL; \ | |
152 | rb_erase(&high_vma->vm_rb, &mm->mm_rb); \ | |
153 | mm->mmap_cache = NULL; \ | |
154 | mm->map_count--; \ | |
155 | remove_vma(high_vma); \ | |
156 | } \ | |
157 | } while (0) | |
158 | ||
159 | static inline void arch_dup_mmap(struct mm_struct *oldmm, | |
160 | struct mm_struct *mm) | |
161 | { | |
162 | } | |
163 | ||
1da177e4 | 164 | #endif |