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Linux kernel mirror (for testing)
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kernel
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linux
1#ifndef _ASM_X86_MMU_CONTEXT_H
2#define _ASM_X86_MMU_CONTEXT_H
3
4#include <asm/desc.h>
5#include <asm/atomic.h>
6#include <asm/pgalloc.h>
7#include <asm/tlbflush.h>
8#include <asm/paravirt.h>
9#ifndef CONFIG_PARAVIRT
10#include <asm-generic/mm_hooks.h>
11
12static inline void paravirt_activate_mm(struct mm_struct *prev,
13 struct mm_struct *next)
14{
15}
16#endif /* !CONFIG_PARAVIRT */
17
18/*
19 * Used for LDT copy/destruction.
20 */
21int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
22void destroy_context(struct mm_struct *mm);
23
24
25static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
26{
27#ifdef CONFIG_SMP
28 if (percpu_read(cpu_tlbstate.state) == TLBSTATE_OK)
29 percpu_write(cpu_tlbstate.state, TLBSTATE_LAZY);
30#endif
31}
32
33static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
34 struct task_struct *tsk)
35{
36 unsigned cpu = smp_processor_id();
37
38 if (likely(prev != next)) {
39 /* stop flush ipis for the previous mm */
40 cpumask_clear_cpu(cpu, mm_cpumask(prev));
41#ifdef CONFIG_SMP
42 percpu_write(cpu_tlbstate.state, TLBSTATE_OK);
43 percpu_write(cpu_tlbstate.active_mm, next);
44#endif
45 cpumask_set_cpu(cpu, mm_cpumask(next));
46
47 /* Re-load page tables */
48 load_cr3(next->pgd);
49
50 /*
51 * load the LDT, if the LDT is different:
52 */
53 if (unlikely(prev->context.ldt != next->context.ldt))
54 load_LDT_nolock(&next->context);
55 }
56#ifdef CONFIG_SMP
57 else {
58 percpu_write(cpu_tlbstate.state, TLBSTATE_OK);
59 BUG_ON(percpu_read(cpu_tlbstate.active_mm) != next);
60
61 if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next))) {
62 /* We were in lazy tlb mode and leave_mm disabled
63 * tlb flush IPI delivery. We must reload CR3
64 * to make sure to use no freed page tables.
65 */
66 load_cr3(next->pgd);
67 load_LDT_nolock(&next->context);
68 }
69 }
70#endif
71}
72
73#define activate_mm(prev, next) \
74do { \
75 paravirt_activate_mm((prev), (next)); \
76 switch_mm((prev), (next), NULL); \
77} while (0);
78
79#ifdef CONFIG_X86_32
80#define deactivate_mm(tsk, mm) \
81do { \
82 lazy_load_gs(0); \
83} while (0)
84#else
85#define deactivate_mm(tsk, mm) \
86do { \
87 load_gs_index(0); \
88 loadsegment(fs, 0); \
89} while (0)
90#endif
91
92#endif /* _ASM_X86_MMU_CONTEXT_H */