1 files changed, 129 insertions, 0 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
new file mode 100644
index 000000000000..68b575afe5f5
--- /dev/null
+++ b/include/linux/context_tracking.h
@@ -0,0 +1,129 @@
+#ifndef _LINUX_CONTEXT_TRACKING_H
+#define _LINUX_CONTEXT_TRACKING_H
+
+#include <linux/sched.h>
+#include <linux/vtime.h>
+#include <linux/context_tracking_state.h>
+#include <asm/ptrace.h>
+
+
+#ifdef CONFIG_CONTEXT_TRACKING
+extern void context_tracking_cpu_set(int cpu);
+
+/* Called with interrupts disabled.  */
+extern void __context_tracking_enter(enum ctx_state state);
+extern void __context_tracking_exit(enum ctx_state state);
+
+extern void context_tracking_enter(enum ctx_state state);
+extern void context_tracking_exit(enum ctx_state state);
+extern void context_tracking_user_enter(void);
+extern void context_tracking_user_exit(void);
+
+static inline void user_enter(void)
+{
+	if (context_tracking_is_enabled())
+		context_tracking_enter(CONTEXT_USER);
+
+}
+static inline void user_exit(void)
+{
+	if (context_tracking_is_enabled())
+		context_tracking_exit(CONTEXT_USER);
+}
+
+static inline enum ctx_state exception_enter(void)
+{
+	enum ctx_state prev_ctx;
+
+	if (!context_tracking_is_enabled())
+		return 0;
+
+	prev_ctx = this_cpu_read(context_tracking.state);
+	if (prev_ctx != CONTEXT_KERNEL)
+		context_tracking_exit(prev_ctx);
+
+	return prev_ctx;
+}
+
+static inline void exception_exit(enum ctx_state prev_ctx)
+{
+	if (context_tracking_is_enabled()) {
+		if (prev_ctx != CONTEXT_KERNEL)
+			context_tracking_enter(prev_ctx);
+	}
+}
+
+
+/**
+ * ct_state() - return the current context tracking state if known
+ *
+ * Returns the current cpu's context tracking state if context tracking
+ * is enabled.  If context tracking is disabled, returns
+ * CONTEXT_DISABLED.  This should be used primarily for debugging.
+ */
+static inline enum ctx_state ct_state(void)
+{
+	return context_tracking_is_enabled() ?
+		this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
+}
+#else
+static inline void user_enter(void) { }
+static inline void user_exit(void) { }
+static inline enum ctx_state exception_enter(void) { return 0; }
+static inline void exception_exit(enum ctx_state prev_ctx) { }
+static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
+#endif /* !CONFIG_CONTEXT_TRACKING */
+
+#define CT_WARN_ON(cond) WARN_ON(context_tracking_is_enabled() && (cond))
+
+#ifdef CONFIG_CONTEXT_TRACKING_FORCE
+extern void context_tracking_init(void);
+#else
+static inline void context_tracking_init(void) { }
+#endif /* CONFIG_CONTEXT_TRACKING_FORCE */
+
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+static inline void guest_enter(void)
+{
+	if (vtime_accounting_enabled())
+		vtime_guest_enter(current);
+	else
+		current->flags |= PF_VCPU;
+
+	if (context_tracking_is_enabled())
+		__context_tracking_enter(CONTEXT_GUEST);
+}
+
+static inline void guest_exit(void)
+{
+	if (context_tracking_is_enabled())
+		__context_tracking_exit(CONTEXT_GUEST);
+
+	if (vtime_accounting_enabled())
+		vtime_guest_exit(current);
+	else
+		current->flags &= ~PF_VCPU;
+}
+
+#else
+static inline void guest_enter(void)
+{
+	/*
+	 * This is running in ioctl context so its safe
+	 * to assume that it's the stime pending cputime
+	 * to flush.
+	 */
+	vtime_account_system(current);
+	current->flags |= PF_VCPU;
+}
+
+static inline void guest_exit(void)
+{
+	/* Flush the guest cputime we spent on the guest */
+	vtime_account_system(current);
+	current->flags &= ~PF_VCPU;
+}
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
+
+#endif