[PATCH V2 1/2] trace,x86: Add external_interrupts to the irq_vectors class

[Daniel Bristot de Oliveira]

Currently, the irq_vectors is showing the entry and exit events for
the interrupts of the architecture, but not for external interrupts.

Adds the tracepoints for external interrupts.

Example of output:
 <idle>-0     [000] d.h.   102.890935: external_interrupt_entry: vector=35
 <idle>-0     [000] d.h.   102.890960: external_interrupt_exit: vector=35

Changes from V1:
  - Fix a compilation problem when CONFIG_X86_LOCAL_APIC is not set (kbuild test)

Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Clark Williams <williams@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
---
 arch/x86/include/asm/trace/irq_vectors.h | 10 +++++++++-
 arch/x86/kernel/irq.c                    |  2 ++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
index 33b9d0f0aafe..38e73d56db70 100644
--- a/arch/x86/include/asm/trace/irq_vectors.h
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -138,6 +138,12 @@ DEFINE_IRQ_VECTOR_EVENT(deferred_error_apic);
 DEFINE_IRQ_VECTOR_EVENT(thermal_apic);
 #endif
 
+/*
+ * external_interrupt - called when entering/exiting from regular device
+ * interrupt vector handler.
+ */
+DEFINE_IRQ_VECTOR_EVENT(external_interrupt);
+
 TRACE_EVENT(vector_config,
 
 	TP_PROTO(unsigned int irq, unsigned int vector,
@@ -385,7 +391,9 @@ TRACE_EVENT(vector_free_moved,
 		  __entry->is_managed)
 );
 
-
+#else /* CONFIG_X86_LOCAL_APIC */
+#define trace_external_interrupt_entry(vector) do {} while(0)
+#define trace_external_interrupt_exit(vector) do {} while(0)
 #endif /* CONFIG_X86_LOCAL_APIC */
 
 #undef TRACE_INCLUDE_PATH
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 59b5f2ea7c2f..715afe3a4f24 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -237,6 +237,7 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 	unsigned vector = ~regs->orig_ax;
 
 	entering_irq();
+	trace_external_interrupt_entry(vector);
 
 	/* entering_irq() tells RCU that we're not quiescent.  Check it. */
 	RCU_LOCKDEP_WARN(!rcu_is_watching(), "IRQ failed to wake up RCU");
@@ -255,6 +256,7 @@ __visible unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 		}
 	}
 
+	trace_external_interrupt_exit(vector);
 	exiting_irq();
 
 	set_irq_regs(old_regs);
-- 
2.19.0