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 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