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Diffstat (limited to 'include/linux/context_tracking_state.h')
-rw-r--r--include/linux/context_tracking_state.h113
1 files changed, 102 insertions, 11 deletions
diff --git a/include/linux/context_tracking_state.h b/include/linux/context_tracking_state.h
index ae1e63e26947..4a4d56f77180 100644
--- a/include/linux/context_tracking_state.h
+++ b/include/linux/context_tracking_state.h
@@ -4,8 +4,28 @@
#include <linux/percpu.h>
#include <linux/static_key.h>
+#include <linux/context_tracking_irq.h>
+
+/* Offset to allow distinguishing irq vs. task-based idle entry/exit. */
+#define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1)
+
+enum ctx_state {
+ CONTEXT_DISABLED = -1, /* returned by ct_state() if unknown */
+ CONTEXT_KERNEL = 0,
+ CONTEXT_IDLE = 1,
+ CONTEXT_USER = 2,
+ CONTEXT_GUEST = 3,
+ CONTEXT_MAX = 4,
+};
+
+/* Even value for idle, else odd. */
+#define RCU_DYNTICKS_IDX CONTEXT_MAX
+
+#define CT_STATE_MASK (CONTEXT_MAX - 1)
+#define CT_DYNTICKS_MASK (~CT_STATE_MASK)
struct context_tracking {
+#ifdef CONFIG_CONTEXT_TRACKING_USER
/*
* When active is false, probes are unset in order
* to minimize overhead: TIF flags are cleared
@@ -14,18 +34,73 @@ struct context_tracking {
*/
bool active;
int recursion;
- enum ctx_state {
- CONTEXT_DISABLED = -1, /* returned by ct_state() if unknown */
- CONTEXT_KERNEL = 0,
- CONTEXT_USER,
- CONTEXT_GUEST,
- } state;
+#endif
+#ifdef CONFIG_CONTEXT_TRACKING
+ atomic_t state;
+#endif
+#ifdef CONFIG_CONTEXT_TRACKING_IDLE
+ long dynticks_nesting; /* Track process nesting level. */
+ long dynticks_nmi_nesting; /* Track irq/NMI nesting level. */
+#endif
};
#ifdef CONFIG_CONTEXT_TRACKING
-extern struct static_key_false context_tracking_key;
DECLARE_PER_CPU(struct context_tracking, context_tracking);
+static __always_inline int __ct_state(void)
+{
+ return arch_atomic_read(this_cpu_ptr(&context_tracking.state)) & CT_STATE_MASK;
+}
+#endif
+
+#ifdef CONFIG_CONTEXT_TRACKING_IDLE
+static __always_inline int ct_dynticks(void)
+{
+ return atomic_read(this_cpu_ptr(&context_tracking.state)) & CT_DYNTICKS_MASK;
+}
+
+static __always_inline int ct_dynticks_cpu(int cpu)
+{
+ struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu);
+
+ return atomic_read(&ct->state) & CT_DYNTICKS_MASK;
+}
+
+static __always_inline int ct_dynticks_cpu_acquire(int cpu)
+{
+ struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu);
+
+ return atomic_read_acquire(&ct->state) & CT_DYNTICKS_MASK;
+}
+
+static __always_inline long ct_dynticks_nesting(void)
+{
+ return __this_cpu_read(context_tracking.dynticks_nesting);
+}
+
+static __always_inline long ct_dynticks_nesting_cpu(int cpu)
+{
+ struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu);
+
+ return ct->dynticks_nesting;
+}
+
+static __always_inline long ct_dynticks_nmi_nesting(void)
+{
+ return __this_cpu_read(context_tracking.dynticks_nmi_nesting);
+}
+
+static __always_inline long ct_dynticks_nmi_nesting_cpu(int cpu)
+{
+ struct context_tracking *ct = per_cpu_ptr(&context_tracking, cpu);
+
+ return ct->dynticks_nmi_nesting;
+}
+#endif /* #ifdef CONFIG_CONTEXT_TRACKING_IDLE */
+
+#ifdef CONFIG_CONTEXT_TRACKING_USER
+extern struct static_key_false context_tracking_key;
+
static __always_inline bool context_tracking_enabled(void)
{
return static_branch_unlikely(&context_tracking_key);
@@ -41,15 +116,31 @@ static inline bool context_tracking_enabled_this_cpu(void)
return context_tracking_enabled() && __this_cpu_read(context_tracking.active);
}
-static __always_inline bool context_tracking_in_user(void)
+/**
+ * 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 __always_inline int ct_state(void)
{
- return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
+ int ret;
+
+ if (!context_tracking_enabled())
+ return CONTEXT_DISABLED;
+
+ preempt_disable();
+ ret = __ct_state();
+ preempt_enable();
+
+ return ret;
}
+
#else
-static __always_inline bool context_tracking_in_user(void) { return false; }
static __always_inline bool context_tracking_enabled(void) { return false; }
static __always_inline bool context_tracking_enabled_cpu(int cpu) { return false; }
static __always_inline bool context_tracking_enabled_this_cpu(void) { return false; }
-#endif /* CONFIG_CONTEXT_TRACKING */
+#endif /* CONFIG_CONTEXT_TRACKING_USER */
#endif