[PATCH] net/phy: add trace events for mdio accesses

["Uwe Kleine-König" <uwe@kleine-koenig.org>]

Make it possible to generate trace events for mdio read and write accesses.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
---
 drivers/net/phy/mdio_bus.c  | 15 +++++++++++++++
 include/trace/events/mdio.h | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 include/trace/events/mdio.h

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 09deef4bed09..0f3f207419f6 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -38,6 +38,9 @@
 
 #include <asm/irq.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/mdio.h>
+
 int mdiobus_register_device(struct mdio_device *mdiodev)
 {
 	if (mdiodev->bus->mdio_map[mdiodev->addr])
@@ -461,6 +464,9 @@ int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
 	retval = bus->read(bus, addr, regnum);
 	mutex_unlock(&bus->mdio_lock);
 
+	if (retval >= 0)
+		trace_mdio_access(bus, 1, addr, regnum, retval);
+
 	return retval;
 }
 EXPORT_SYMBOL(mdiobus_read_nested);
@@ -485,6 +491,9 @@ int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
 	retval = bus->read(bus, addr, regnum);
 	mutex_unlock(&bus->mdio_lock);
 
+	if (retval >= 0)
+		trace_mdio_access(bus, 1, addr, regnum, retval);
+
 	return retval;
 }
 EXPORT_SYMBOL(mdiobus_read);
@@ -513,6 +522,9 @@ int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 	err = bus->write(bus, addr, regnum, val);
 	mutex_unlock(&bus->mdio_lock);
 
+	if (!err)
+		trace_mdio_access(bus, 0, addr, regnum, val);
+
 	return err;
 }
 EXPORT_SYMBOL(mdiobus_write_nested);
@@ -538,6 +550,9 @@ int mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
 	err = bus->write(bus, addr, regnum, val);
 	mutex_unlock(&bus->mdio_lock);
 
+	if (!err)
+		trace_mdio_access(bus, 0, addr, regnum, val);
+
 	return err;
 }
 EXPORT_SYMBOL(mdiobus_write);
diff --git a/include/trace/events/mdio.h b/include/trace/events/mdio.h
new file mode 100644
index 000000000000..dcb2d456a346
--- /dev/null
+++ b/include/trace/events/mdio.h
@@ -0,0 +1,40 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM mdio
+
+#if !defined(_TRACE_MDIO_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_MDIO_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(mdio_access,
+
+	TP_PROTO(struct mii_bus *bus, int read,
+		 unsigned addr, unsigned regnum, u16 val),
+
+	TP_ARGS(bus, read, addr, regnum, val),
+
+	TP_STRUCT__entry(
+		__array(char, busid, MII_BUS_ID_SIZE)
+		__field(int, read)
+		__field(unsigned, addr)
+		__field(unsigned, regnum)
+		__field(u16, val)
+	),
+
+	TP_fast_assign(
+		strncpy(__entry->busid, bus->id, MII_BUS_ID_SIZE);
+		__entry->read = read;
+		__entry->addr = addr;
+		__entry->regnum = regnum;
+		__entry->val = val;
+	),
+
+	TP_printk("%s %-5s phy:0x%02x reg:0x%02x val:0x%04hx",
+		  __entry->busid, __entry->read ? "read" : "write",
+		  __entry->addr, __entry->regnum, __entry->val)
+);
+
+#endif /* if !defined(_TRACE_MDIO_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.10.2