2 * arch/arm/include/asm/mmu_context.h
4 * Copyright (C) 1996 Russell King.
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.
11 * 27-06-1996 RMK Created
13 #ifndef __ASM_ARM_MMU_CONTEXT_H
14 #define __ASM_ARM_MMU_CONTEXT_H
16 #include <linux/compiler.h>
17 #include <linux/sched.h>
18 #include <asm/cacheflush.h>
19 #include <asm/cachetype.h>
20 #include <asm/proc-fns.h>
21 #include <asm/smp_plat.h>
22 #include <asm-generic/mm_hooks.h>
24 void __check_vmalloc_seq(struct mm_struct
*mm
);
26 #ifdef CONFIG_CPU_HAS_ASID
28 void check_and_switch_context(struct mm_struct
*mm
, struct task_struct
*tsk
);
30 init_new_context(struct task_struct
*tsk
, struct mm_struct
*mm
)
32 atomic64_set(&mm
->context
.id
, 0);
36 #ifdef CONFIG_ARM_ERRATA_798181
37 void a15_erratum_get_cpumask(int this_cpu
, struct mm_struct
*mm
,
39 #else /* !CONFIG_ARM_ERRATA_798181 */
40 static inline void a15_erratum_get_cpumask(int this_cpu
, struct mm_struct
*mm
,
44 #endif /* CONFIG_ARM_ERRATA_798181 */
46 #else /* !CONFIG_CPU_HAS_ASID */
50 static inline void check_and_switch_context(struct mm_struct
*mm
,
51 struct task_struct
*tsk
)
53 if (unlikely(mm
->context
.vmalloc_seq
!= init_mm
.context
.vmalloc_seq
))
54 __check_vmalloc_seq(mm
);
58 * cpu_switch_mm() needs to flush the VIVT caches. To avoid
59 * high interrupt latencies, defer the call and continue
60 * running with the old mm. Since we only support UP systems
61 * on non-ASID CPUs, the old mm will remain valid until the
62 * finish_arch_post_lock_switch() call.
64 mm
->context
.switch_pending
= 1;
66 cpu_switch_mm(mm
->pgd
, mm
);
69 #define finish_arch_post_lock_switch \
70 finish_arch_post_lock_switch
71 static inline void finish_arch_post_lock_switch(void)
73 struct mm_struct
*mm
= current
->mm
;
75 if (mm
&& mm
->context
.switch_pending
) {
77 * Preemption must be disabled during cpu_switch_mm() as we
78 * have some stateful cache flush implementations. Check
79 * switch_pending again in case we were preempted and the
80 * switch to this mm was already done.
83 if (mm
->context
.switch_pending
) {
84 mm
->context
.switch_pending
= 0;
85 cpu_switch_mm(mm
->pgd
, mm
);
87 preempt_enable_no_resched();
91 #endif /* CONFIG_MMU */
94 init_new_context(struct task_struct
*tsk
, struct mm_struct
*mm
)
100 #endif /* CONFIG_CPU_HAS_ASID */
102 #define destroy_context(mm) do { } while(0)
103 #define activate_mm(prev,next) switch_mm(prev, next, NULL)
106 * This is called when "tsk" is about to enter lazy TLB mode.
108 * mm: describes the currently active mm context
109 * tsk: task which is entering lazy tlb
110 * cpu: cpu number which is entering lazy tlb
112 * tsk->mm will be NULL
115 enter_lazy_tlb(struct mm_struct
*mm
, struct task_struct
*tsk
)
120 * This is the actual mm switch as far as the scheduler
121 * is concerned. No registers are touched. We avoid
122 * calling the CPU specific function when the mm hasn't
126 switch_mm(struct mm_struct
*prev
, struct mm_struct
*next
,
127 struct task_struct
*tsk
)
130 unsigned int cpu
= smp_processor_id();
133 * __sync_icache_dcache doesn't broadcast the I-cache invalidation,
134 * so check for possible thread migration and invalidate the I-cache
135 * if we're new to this CPU.
137 if (cache_ops_need_broadcast() &&
138 !cpumask_empty(mm_cpumask(next
)) &&
139 !cpumask_test_cpu(cpu
, mm_cpumask(next
)))
140 __flush_icache_all();
142 if (!cpumask_test_and_set_cpu(cpu
, mm_cpumask(next
)) || prev
!= next
) {
143 check_and_switch_context(next
, tsk
);
145 cpumask_clear_cpu(cpu
, mm_cpumask(prev
));
150 #define deactivate_mm(tsk,mm) do { } while (0)
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