kernel/include/linux/context_tracking.h

   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
  22 static inline void user_enter(void)
  23 {
  24         if (context_tracking_is_enabled())
  25                 context_tracking_enter(CONTEXT_USER);
  26
  27 }
  28 static inline void user_exit(void)
  29 {
  30         if (context_tracking_is_enabled())
  31                 context_tracking_exit(CONTEXT_USER);
  32 }
  33
  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
  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  */
  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
  70 static inline void user_enter(void) { }
  71 static inline void user_exit(void) { }
  72 static inline enum ctx_state exception_enter(void) { return 0; }
  73 static inline void exception_exit(enum ctx_state prev_ctx) { }
  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
  82 static inline void context_tracking_init(void) { }
  83 #endif /* CONFIG_CONTEXT_TRACKING_FORCE */
  84
  85
  86 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
  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
  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
 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
 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