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authorRalf Baechle <[email protected]>2013-02-21 16:16:55 +0100
committerRalf Baechle <[email protected]>2013-02-22 10:07:30 +0100
commitedb15d83a875a1f4b1576188844db5c330c3267d (patch)
tree74d54eab401b6ccf2a6ad4821227108a8d160f03 /include/linux/context_tracking.h
parent8bfc245f9ad7bd4e461179e4e7852ef99b8b6144 (diff)
parenta0b1c42951dd06ec83cc1bc2c9788131d9fefcd8 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into mips-for-linux-next
Conflicts: include/linux/ssb/ssb_driver_gige.h Also resolves a logical merge conflict in drivers/net/ethernet/broadcom/- bgmac.c due to change of an API.
Diffstat (limited to 'include/linux/context_tracking.h')
-rw-r--r--include/linux/context_tracking.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index e24339ccb7f0..b28d161c1091 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -3,12 +3,40 @@
#ifdef CONFIG_CONTEXT_TRACKING
#include <linux/sched.h>
+#include <linux/percpu.h>
+
+struct context_tracking {
+ /*
+ * When active is false, probes are unset in order
+ * to minimize overhead: TIF flags are cleared
+ * and calls to user_enter/exit are ignored. This
+ * may be further optimized using static keys.
+ */
+ bool active;
+ enum {
+ IN_KERNEL = 0,
+ IN_USER,
+ } state;
+};
+
+DECLARE_PER_CPU(struct context_tracking, context_tracking);
+
+static inline bool context_tracking_in_user(void)
+{
+ return __this_cpu_read(context_tracking.state) == IN_USER;
+}
+
+static inline bool context_tracking_active(void)
+{
+ return __this_cpu_read(context_tracking.active);
+}
extern void user_enter(void);
extern void user_exit(void);
extern void context_tracking_task_switch(struct task_struct *prev,
struct task_struct *next);
#else
+static inline bool context_tracking_in_user(void) { return false; }
static inline void user_enter(void) { }
static inline void user_exit(void) { }
static inline void context_tracking_task_switch(struct task_struct *prev,