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 /* Called with interrupts disabled.  */
14 extern void __context_tracking_enter(enum ctx_state state);
15 extern void __context_tracking_exit(enum ctx_state state);
16 
17 extern void context_tracking_enter(enum ctx_state state);
18 extern void context_tracking_exit(enum ctx_state state);
19 extern void context_tracking_user_enter(void);
20 extern void context_tracking_user_exit(void);
21 
user_enter(void)22 static inline void user_enter(void)
23 {
24 	if (context_tracking_is_enabled())
25 		context_tracking_enter(CONTEXT_USER);
26 
27 }
user_exit(void)28 static inline void user_exit(void)
29 {
30 	if (context_tracking_is_enabled())
31 		context_tracking_exit(CONTEXT_USER);
32 }
33 
exception_enter(void)34 static inline enum ctx_state exception_enter(void)
35 {
36 	enum ctx_state prev_ctx;
37 
38 	if (!context_tracking_is_enabled())
39 		return 0;
40 
41 	prev_ctx = this_cpu_read(context_tracking.state);
42 	if (prev_ctx != CONTEXT_KERNEL)
43 		context_tracking_exit(prev_ctx);
44 
45 	return prev_ctx;
46 }
47 
exception_exit(enum ctx_state prev_ctx)48 static inline void exception_exit(enum ctx_state prev_ctx)
49 {
50 	if (context_tracking_is_enabled()) {
51 		if (prev_ctx != CONTEXT_KERNEL)
52 			context_tracking_enter(prev_ctx);
53 	}
54 }
55 
56 
57 /**
58  * ct_state() - return the current context tracking state if known
59  *
60  * Returns the current cpu's context tracking state if context tracking
61  * is enabled.  If context tracking is disabled, returns
62  * CONTEXT_DISABLED.  This should be used primarily for debugging.
63  */
ct_state(void)64 static inline enum ctx_state ct_state(void)
65 {
66 	return context_tracking_is_enabled() ?
67 		this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
68 }
69 #else
user_enter(void)70 static inline void user_enter(void) { }
user_exit(void)71 static inline void user_exit(void) { }
exception_enter(void)72 static inline enum ctx_state exception_enter(void) { return 0; }
exception_exit(enum ctx_state prev_ctx)73 static inline void exception_exit(enum ctx_state prev_ctx) { }
ct_state(void)74 static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
75 #endif /* !CONFIG_CONTEXT_TRACKING */
76 
77 #define CT_WARN_ON(cond) WARN_ON(context_tracking_is_enabled() && (cond))
78 
79 #ifdef CONFIG_CONTEXT_TRACKING_FORCE
80 extern void context_tracking_init(void);
81 #else
context_tracking_init(void)82 static inline void context_tracking_init(void) { }
83 #endif /* CONFIG_CONTEXT_TRACKING_FORCE */
84 
85 
86 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
guest_enter(void)87 static inline void guest_enter(void)
88 {
89 	if (vtime_accounting_enabled())
90 		vtime_guest_enter(current);
91 	else
92 		current->flags |= PF_VCPU;
93 
94 	if (context_tracking_is_enabled())
95 		__context_tracking_enter(CONTEXT_GUEST);
96 }
97 
guest_exit(void)98 static inline void guest_exit(void)
99 {
100 	if (context_tracking_is_enabled())
101 		__context_tracking_exit(CONTEXT_GUEST);
102 
103 	if (vtime_accounting_enabled())
104 		vtime_guest_exit(current);
105 	else
106 		current->flags &= ~PF_VCPU;
107 }
108 
109 #else
guest_enter(void)110 static inline void guest_enter(void)
111 {
112 	/*
113 	 * This is running in ioctl context so its safe
114 	 * to assume that it's the stime pending cputime
115 	 * to flush.
116 	 */
117 	vtime_account_system(current);
118 	current->flags |= PF_VCPU;
119 }
120 
guest_exit(void)121 static inline void guest_exit(void)
122 {
123 	/* Flush the guest cputime we spent on the guest */
124 	vtime_account_system(current);
125 	current->flags &= ~PF_VCPU;
126 }
127 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
128 
129 #endif
130