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 | 20 | #include <asm/proc-fns.h> |
d6dd61c8 | 21 | #include <asm-generic/mm_hooks.h> |
1da177e4 | 22 | |
ff0daca5 RK |
23 | void __check_kvm_seq(struct mm_struct *mm); |
24 | ||
516793c6 | 25 | #ifdef CONFIG_CPU_HAS_ASID |
1da177e4 LT |
26 | |
27 | /* | |
28 | * On ARMv6, we have the following structure in the Context ID: | |
29 | * | |
30 | * 31 7 0 | |
31 | * +-------------------------+-----------+ | |
32 | * | process ID | ASID | | |
33 | * +-------------------------+-----------+ | |
34 | * | context ID | | |
35 | * +-------------------------------------+ | |
36 | * | |
37 | * The ASID is used to tag entries in the CPU caches and TLBs. | |
38 | * The context ID is used by debuggers and trace logic, and | |
39 | * should be unique within all running processes. | |
40 | */ | |
8678c1f0 RK |
41 | #define ASID_BITS 8 |
42 | #define ASID_MASK ((~0) << ASID_BITS) | |
43 | #define ASID_FIRST_VERSION (1 << ASID_BITS) | |
1da177e4 LT |
44 | |
45 | extern unsigned int cpu_last_asid; | |
46 | ||
47 | void __init_new_context(struct task_struct *tsk, struct mm_struct *mm); | |
48 | void __new_context(struct mm_struct *mm); | |
49 | ||
50 | static inline void check_context(struct mm_struct *mm) | |
51 | { | |
52 | if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS)) | |
53 | __new_context(mm); | |
ff0daca5 RK |
54 | |
55 | if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq)) | |
56 | __check_kvm_seq(mm); | |
1da177e4 LT |
57 | } |
58 | ||
59 | #define init_new_context(tsk,mm) (__init_new_context(tsk,mm),0) | |
60 | ||
61 | #else | |
62 | ||
ff0daca5 RK |
63 | static inline void check_context(struct mm_struct *mm) |
64 | { | |
65 | if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq)) | |
66 | __check_kvm_seq(mm); | |
67 | } | |
68 | ||
1da177e4 LT |
69 | #define init_new_context(tsk,mm) 0 |
70 | ||
71 | #endif | |
72 | ||
73 | #define destroy_context(mm) do { } while(0) | |
74 | ||
75 | /* | |
76 | * This is called when "tsk" is about to enter lazy TLB mode. | |
77 | * | |
78 | * mm: describes the currently active mm context | |
79 | * tsk: task which is entering lazy tlb | |
80 | * cpu: cpu number which is entering lazy tlb | |
81 | * | |
82 | * tsk->mm will be NULL | |
83 | */ | |
84 | static inline void | |
85 | enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) | |
86 | { | |
87 | } | |
88 | ||
89 | /* | |
90 | * This is the actual mm switch as far as the scheduler | |
91 | * is concerned. No registers are touched. We avoid | |
92 | * calling the CPU specific function when the mm hasn't | |
93 | * actually changed. | |
94 | */ | |
95 | static inline void | |
96 | switch_mm(struct mm_struct *prev, struct mm_struct *next, | |
97 | struct task_struct *tsk) | |
98 | { | |
002547b4 | 99 | #ifdef CONFIG_MMU |
1da177e4 LT |
100 | unsigned int cpu = smp_processor_id(); |
101 | ||
826cbdaf CM |
102 | #ifdef CONFIG_SMP |
103 | /* check for possible thread migration */ | |
104 | if (!cpus_empty(next->cpu_vm_mask) && !cpu_isset(cpu, next->cpu_vm_mask)) | |
105 | __flush_icache_all(); | |
106 | #endif | |
8678c1f0 | 107 | if (!cpu_test_and_set(cpu, next->cpu_vm_mask) || prev != next) { |
1da177e4 LT |
108 | check_context(next); |
109 | cpu_switch_mm(next->pgd, next); | |
7e5e6e9a RK |
110 | if (cache_is_vivt()) |
111 | cpu_clear(cpu, prev->cpu_vm_mask); | |
1da177e4 | 112 | } |
002547b4 | 113 | #endif |
1da177e4 LT |
114 | } |
115 | ||
116 | #define deactivate_mm(tsk,mm) do { } while (0) | |
117 | #define activate_mm(prev,next) switch_mm(prev, next, NULL) | |
118 | ||
119 | #endif |