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> |
4fe15ba0 | 17 | #include <asm/cacheflush.h> |
46097c7d | 18 | #include <asm/cachetype.h> |
1da177e4 | 19 | #include <asm/proc-fns.h> |
d6dd61c8 | 20 | #include <asm-generic/mm_hooks.h> |
1da177e4 | 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; | |
45 | ||
46 | void __init_new_context(struct task_struct *tsk, struct mm_struct *mm); | |
47 | void __new_context(struct mm_struct *mm); | |
48 | ||
49 | static inline void check_context(struct mm_struct *mm) | |
50 | { | |
51 | if (unlikely((mm->context.id ^ cpu_last_asid) >> ASID_BITS)) | |
52 | __new_context(mm); | |
ff0daca5 RK |
53 | |
54 | if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq)) | |
55 | __check_kvm_seq(mm); | |
1da177e4 LT |
56 | } |
57 | ||
58 | #define init_new_context(tsk,mm) (__init_new_context(tsk,mm),0) | |
59 | ||
60 | #else | |
61 | ||
ff0daca5 RK |
62 | static inline void check_context(struct mm_struct *mm) |
63 | { | |
64 | if (unlikely(mm->context.kvm_seq != init_mm.context.kvm_seq)) | |
65 | __check_kvm_seq(mm); | |
66 | } | |
67 | ||
1da177e4 LT |
68 | #define init_new_context(tsk,mm) 0 |
69 | ||
70 | #endif | |
71 | ||
72 | #define destroy_context(mm) do { } while(0) | |
73 | ||
74 | /* | |
75 | * This is called when "tsk" is about to enter lazy TLB mode. | |
76 | * | |
77 | * mm: describes the currently active mm context | |
78 | * tsk: task which is entering lazy tlb | |
79 | * cpu: cpu number which is entering lazy tlb | |
80 | * | |
81 | * tsk->mm will be NULL | |
82 | */ | |
83 | static inline void | |
84 | enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) | |
85 | { | |
86 | } | |
87 | ||
88 | /* | |
89 | * This is the actual mm switch as far as the scheduler | |
90 | * is concerned. No registers are touched. We avoid | |
91 | * calling the CPU specific function when the mm hasn't | |
92 | * actually changed. | |
93 | */ | |
94 | static inline void | |
95 | switch_mm(struct mm_struct *prev, struct mm_struct *next, | |
96 | struct task_struct *tsk) | |
97 | { | |
002547b4 | 98 | #ifdef CONFIG_MMU |
1da177e4 LT |
99 | unsigned int cpu = smp_processor_id(); |
100 | ||
826cbdaf CM |
101 | #ifdef CONFIG_SMP |
102 | /* check for possible thread migration */ | |
103 | if (!cpus_empty(next->cpu_vm_mask) && !cpu_isset(cpu, next->cpu_vm_mask)) | |
104 | __flush_icache_all(); | |
105 | #endif | |
8678c1f0 | 106 | if (!cpu_test_and_set(cpu, next->cpu_vm_mask) || prev != next) { |
1da177e4 LT |
107 | check_context(next); |
108 | cpu_switch_mm(next->pgd, next); | |
7e5e6e9a RK |
109 | if (cache_is_vivt()) |
110 | cpu_clear(cpu, prev->cpu_vm_mask); | |
1da177e4 | 111 | } |
002547b4 | 112 | #endif |
1da177e4 LT |
113 | } |
114 | ||
115 | #define deactivate_mm(tsk,mm) do { } while (0) | |
116 | #define activate_mm(prev,next) switch_mm(prev, next, NULL) | |
117 | ||
118 | #endif |