[PATCH V3] trace/events: add chip name and hwirq to irq entry tracepoint

[Ankit Gupta]

Add chip name and hw-irq number to the trace_irq_handler_entry()
tracepoint. When tracing interrupt events the chip-name and hw-irq
numbers are stable and known in advance. This makes them a better
choice as a filtering criteria for the trace buffer dump. On the
flipside, the os-irq numbers are dynamically allocated which makes
them difficult to use for the same purpose.

Dump messages will look like:
...irq_handler_entry: irq=22 name=msm_serial0 chip_name=GIC hwirq=140

Suggested-by: Stephen Boyd <sboyd at codeaurora.org>
Reviewed-by: Andy Gross <agross at codeaurora.org>
Signed-off-by: Gilad Avidov <gavidov at codeaurora.org>
Signed-off-by: Ankit Gupta <ankgupta at codeaurora.org>
---
Changes since V2:
- fixed dump message in commit text to reflect Chip name
  instead of domain.
---
Changes since V1:
- added reviewed by Andy Gross
---
 include/trace/events/irq.h | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/include/trace/events/irq.h b/include/trace/events/irq.h
index 3608beb..5370075 100644
--- a/include/trace/events/irq.h
+++ b/include/trace/events/irq.h
@@ -23,6 +23,17 @@ struct softirq_action;
 			 softirq_name(HRTIMER),		\
 			 softirq_name(RCU))
 
+
+#define show_chip_name(irq)					\
+	(irq_get_irq_data(irq)					\
+			 ? irq_get_irq_data(irq)->chip->name	\
+			 : "NULL")
+
+#define show_hwirq(irq)						\
+	(irq_get_irq_data(irq)					\
+			 ? irq_get_irq_data(irq)->hwirq		\
+			 : -ENODEV)
+
 /**
  * irq_handler_entry - called immediately before the irq action handler
  * @irq: irq number
@@ -50,7 +61,9 @@ TRACE_EVENT(irq_handler_entry,
 		__assign_str(name, action->name);
 	),
 
-	TP_printk("irq=%d name=%s", __entry->irq, __get_str(name))
+	TP_printk("irq=%d name=%s chip_name=%s hwirq=%ld", __entry->irq,
+	  __get_str(name), show_chip_name(__entry->irq),
+	  show_hwirq(__entry->irq))
 );
 
 /**
-- 
1.8.5.2