[PATCH linux dev-4.10 04/16] fsi: occ: Add tracepoints

[Andrew Jeffery]

The OCC driver uses a workqueue to manage calls through to the SBEFIFO, which
in turn uses a timer callback to execute FIFO transfers. To ease observation of
end-to-end interactions e.g. from userspace `cat`ing an OCC hwmon attribute,
add tracing to book-end SBEFIFO transfers. This provides some perspective on
the time taken for a single OCC operation to take place.

Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
 drivers/fsi/occ.c          |  9 +++++
 include/trace/events/occ.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)
 create mode 100644 include/trace/events/occ.h

diff --git a/drivers/fsi/occ.c b/drivers/fsi/occ.c
index adc64f3fcd0a..2313b6235ba3 100644
--- a/drivers/fsi/occ.c
+++ b/drivers/fsi/occ.c
@@ -30,6 +30,9 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/occ.h>
+
 #define OCC_SRAM_BYTES		4096
 #define OCC_CMD_DATA_BYTES	4090
 #define OCC_RESP_DATA_BYTES	4089
@@ -131,6 +134,8 @@ static int occ_enqueue_xfr(struct occ_xfr *xfr)
 
 	spin_unlock_irq(&occ->list_lock);
 
+	trace_occ_enq_xfer(client, xfr);
+
 	if (empty)
 		queue_work(occ_wq, &occ->work);
 
@@ -275,6 +280,7 @@ static ssize_t occ_read_common(struct occ_client *client, char __user *ubuf,
 
 done:
 	spin_unlock_irq(&client->lock);
+	trace_occ_read_complete(client, xfr);
 	occ_put_client(client);
 	return rc;
 }
@@ -305,6 +311,7 @@ static ssize_t occ_write_common(struct occ_client *client,
 	occ_get_client(client);
 	xfr = &client->xfr;
 
+	trace_occ_write_begin(client, xfr);
 	spin_lock_irq(&client->lock);
 
 	if (test_bit(CLIENT_XFR_PENDING, &client->flags)) {
@@ -633,6 +640,7 @@ static void occ_worker(struct work_struct *work)
 	set_bit(XFR_IN_PROGRESS, &xfr->flags);
 
 	spin_unlock_irq(&occ->list_lock);
+	trace_occ_worker_xfer_begin(client, xfr);
 	mutex_lock(&occ->occ_lock);
 
 	start = jiffies;
@@ -695,6 +703,7 @@ static void occ_worker(struct work_struct *work)
 	spin_unlock_irq(&occ->list_lock);
 
 	wake_up_interruptible(&client->wait);
+	trace_occ_worker_xfer_complete(client, xfr);
 	occ_put_client(client);
 
 	if (!empty)
diff --git a/include/trace/events/occ.h b/include/trace/events/occ.h
new file mode 100644
index 000000000000..81395ca32ee0
--- /dev/null
+++ b/include/trace/events/occ.h
@@ -0,0 +1,86 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM occ
+
+#if !defined(_TRACE_TIMER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_OCC_H
+
+#include <linux/tracepoint.h>
+#include <linux/occ.h>
+
+TRACE_EVENT(occ_enq_xfer,
+	TP_PROTO(const void *client, const void *xfer),
+	TP_ARGS(client, xfer),
+	TP_STRUCT__entry(
+		__field(const void *, client)
+		__field(const void *, xfer)
+	),
+	TP_fast_assign(
+		__entry->client = client;
+		__entry->xfer = xfer;
+	),
+	TP_printk("Client %p enqueued xfer %p", __entry->client, __entry->xfer)
+);
+
+TRACE_EVENT(occ_read_complete,
+	TP_PROTO(const void *client, const void *xfer),
+	TP_ARGS(client, xfer),
+	TP_STRUCT__entry(
+		__field(const void *, client)
+		__field(const void *, xfer)
+	),
+	TP_fast_assign(
+		__entry->client = client;
+		__entry->xfer = xfer;
+	),
+	TP_printk("Client %p completed read for xfer %p",
+		__entry->client, __entry->xfer)
+);
+
+TRACE_EVENT(occ_write_begin,
+	TP_PROTO(const void *client, const void *xfer),
+	TP_ARGS(client, xfer),
+	TP_STRUCT__entry(
+		__field(const void *, client)
+		__field(const void *, xfer)
+	),
+	TP_fast_assign(
+		__entry->client = client;
+		__entry->xfer = xfer;
+	),
+	TP_printk("Client %p began write for xfer %p",
+		__entry->client, __entry->xfer)
+);
+
+TRACE_EVENT(occ_worker_xfer_begin,
+	TP_PROTO(const void *client, const void *xfer),
+	TP_ARGS(client, xfer),
+	TP_STRUCT__entry(
+		__field(const void *, client)
+		__field(const void *, xfer)
+	),
+	TP_fast_assign(
+		__entry->client = client;
+		__entry->xfer = xfer;
+	),
+	TP_printk("OCC worker began client %p xfer %p",
+		__entry->client, __entry->xfer)
+);
+
+TRACE_EVENT(occ_worker_xfer_complete,
+	TP_PROTO(const void *client, const void *xfer),
+	TP_ARGS(client, xfer),
+	TP_STRUCT__entry(
+		__field(const void *, client)
+		__field(const void *, xfer)
+	),
+	TP_fast_assign(
+		__entry->client = client;
+		__entry->xfer = xfer;
+	),
+	TP_printk("OCC worker completed client %p xfer %p",
+		__entry->client, __entry->xfer)
+);
+
+#endif
+
+#include <trace/define_trace.h>
-- 
2.14.1