1 #ifndef _LINUX_CONTEXT_TRACKING_H
2 #define _LINUX_CONTEXT_TRACKING_H
3 
4 #include <linux/sched.h>
5 #include <linux/vtime.h>
6 #include <linux/context_tracking_state.h>
7 #include <asm/ptrace.h>
8 
9 
10 #ifdef CONFIG_CONTEXT_TRACKING
11 extern void context_tracking_cpu_set(int cpu);
12 
13 extern void context_tracking_enter(enum ctx_state state);
14 extern void context_tracking_exit(enum ctx_state state);
15 extern void context_tracking_user_enter(void);
16 extern void context_tracking_user_exit(void);
17 
18 static inline void user_enter(void)
19 {
20 	if (context_tracking_is_enabled())
21 		context_tracking_user_enter();
22 
23 }
24 static inline void user_exit(void)
25 {
26 	if (context_tracking_is_enabled())
27 		context_tracking_user_exit();
28 }
29 
30 static inline enum ctx_state exception_enter(void)
31 {
32 	enum ctx_state prev_ctx;
33 
34 	if (!context_tracking_is_enabled())
35 		return 0;
36 
37 	prev_ctx = this_cpu_read(context_tracking.state);
38 	if (prev_ctx != CONTEXT_KERNEL)
39 		context_tracking_exit(prev_ctx);
40 
41 	return prev_ctx;
42 }
43 
44 static inline void exception_exit(enum ctx_state prev_ctx)
45 {
46 	if (context_tracking_is_enabled()) {
47 		if (prev_ctx != CONTEXT_KERNEL)
48 			context_tracking_enter(prev_ctx);
49 	}
50 }
51 
52 
53 /**
54  * ct_state() - return the current context tracking state if known
55  *
56  * Returns the current cpu's context tracking state if context tracking
57  * is enabled.  If context tracking is disabled, returns
58  * CONTEXT_DISABLED.  This should be used primarily for debugging.
59  */
60 static inline enum ctx_state ct_state(void)
61 {
62 	return context_tracking_is_enabled() ?
63 		this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
64 }
65 #else
66 static inline void user_enter(void) { }
67 static inline void user_exit(void) { }
68 static inline enum ctx_state exception_enter(void) { return 0; }
69 static inline void exception_exit(enum ctx_state prev_ctx) { }
70 static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
71 #endif /* !CONFIG_CONTEXT_TRACKING */
72 
73 #define CT_WARN_ON(cond) WARN_ON(context_tracking_is_enabled() && (cond))
74 
75 #ifdef CONFIG_CONTEXT_TRACKING_FORCE
76 extern void context_tracking_init(void);
77 #else
78 static inline void context_tracking_init(void) { }
79 #endif /* CONFIG_CONTEXT_TRACKING_FORCE */
80 
81 
82 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
83 static inline void guest_enter(void)
84 {
85 	if (vtime_accounting_enabled())
86 		vtime_guest_enter(current);
87 	else
88 		current->flags |= PF_VCPU;
89 
90 	if (context_tracking_is_enabled())
91 		context_tracking_enter(CONTEXT_GUEST);
92 }
93 
94 static inline void guest_exit(void)
95 {
96 	if (context_tracking_is_enabled())
97 		context_tracking_exit(CONTEXT_GUEST);
98 
99 	if (vtime_accounting_enabled())
100 		vtime_guest_exit(current);
101 	else
102 		current->flags &= ~PF_VCPU;
103 }
104 
105 #else
106 static inline void guest_enter(void)
107 {
108 	/*
109 	 * This is running in ioctl context so its safe
110 	 * to assume that it's the stime pending cputime
111 	 * to flush.
112 	 */
113 	vtime_account_system(current);
114 	current->flags |= PF_VCPU;
115 }
116 
117 static inline void guest_exit(void)
118 {
119 	/* Flush the guest cputime we spent on the guest */
120 	vtime_account_system(current);
121 	current->flags &= ~PF_VCPU;
122 }
123 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
124 
125 #endif
126