LXR linux/include/linux/context

   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
  11extern void context_tracking_cpu_set(int cpu);
  12
  13/* Called with interrupts disabled.  */
  14extern void __context_tracking_enter(enum ctx_state state);
  15extern void __context_tracking_exit(enum ctx_state state);
  16
  17extern void context_tracking_enter(enum ctx_state state);
  18extern void context_tracking_exit(enum ctx_state state);
  19extern void context_tracking_user_enter(void);
  20extern void context_tracking_user_exit(void);
  21
  22static inline void user_enter(void)
  23{
  24        if (context_tracking_is_enabled())
  25                context_tracking_enter(CONTEXT_USER);
  26
  27}
  28static inline void user_exit(void)
  29{
  30        if (context_tracking_is_enabled())
  31                context_tracking_exit(CONTEXT_USER);
  32}
  33
  34static 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
  48static 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 */
  64static 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
  70static inline void user_enter(void) { }
  71static inline void user_exit(void) { }
  72static inline enum ctx_state exception_enter(void) { return 0; }
  73static inline void exception_exit(enum ctx_state prev_ctx) { }
  74static 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
  80extern void context_tracking_init(void);
  81#else
  82static inline void context_tracking_init(void) { }
  83#endif /* CONFIG_CONTEXT_TRACKING_FORCE */
  84
  85
  86#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
  87static inline void guest_enter(void)
  88{
  89        if (vtime_accounting_cpu_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
  98static inline void guest_exit(void)
  99{
 100        if (context_tracking_is_enabled())
 101                __context_tracking_exit(CONTEXT_GUEST);
 102
 103        if (vtime_accounting_cpu_enabled())
 104                vtime_guest_exit(current);
 105        else
 106                current->flags &= ~PF_VCPU;
 107}
 108
 109#else
 110static 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
 121static 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