[PATCH] clk: Add tracepoints for hardware operations

Stephen Boyd sboyd at codeaurora.org
Mon Jun 30 16:56:39 PDT 2014


It's useful to have tracepoints around operations that change the
hardware state so that we can debug clock hardware performance
and operations. Three basic types of events are supported: on/off
events for enable, disable, prepare, unprepare that only record
an event and a clock name, rate changing events for
clk_set_rate() and parent changing events for clk_set_parent().

Cc: Steven Rostedt <rostedt at goodmis.org>
Signed-off-by: Stephen Boyd <sboyd at codeaurora.org>
---

I see that there are tracepoints for clock_enable/clock_set_rate
in events/power.h but those look to be unused and they also
take cpu_id which seems odd. I'd rather we just make a new set of
events for the common clock framework instead and add the "_complete"
set of events so we know when things have completed.

 drivers/clk/clk.c          |  28 ++++++++
 include/trace/events/clk.h | 165 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 193 insertions(+)
 create mode 100644 include/trace/events/clk.h

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 8b73edef151d..f8bf69df3210 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -21,6 +21,9 @@
 #include <linux/init.h>
 #include <linux/sched.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/clk.h>
+
 #include "clk.h"
 
 static DEFINE_SPINLOCK(enable_lock);
@@ -483,10 +486,12 @@ static void clk_unprepare_unused_subtree(struct clk *clk)
 		return;
 
 	if (__clk_is_prepared(clk)) {
+		trace_clk_unprepare(clk);
 		if (clk->ops->unprepare_unused)
 			clk->ops->unprepare_unused(clk->hw);
 		else if (clk->ops->unprepare)
 			clk->ops->unprepare(clk->hw);
+		trace_clk_unprepare_complete(clk);
 	}
 }
 
@@ -516,10 +521,12 @@ static void clk_disable_unused_subtree(struct clk *clk)
 	 * back to .disable
 	 */
 	if (__clk_is_enabled(clk)) {
+		trace_clk_disable(clk);
 		if (clk->ops->disable_unused)
 			clk->ops->disable_unused(clk->hw);
 		else if (clk->ops->disable)
 			clk->ops->disable(clk->hw);
+		trace_clk_disable_complete(clk);
 	}
 
 unlock_out:
@@ -802,9 +809,13 @@ void __clk_unprepare(struct clk *clk)
 
 	WARN_ON(clk->enable_count > 0);
 
+	trace_clk_unprepare(clk);
+
 	if (clk->ops->unprepare)
 		clk->ops->unprepare(clk->hw);
 
+	trace_clk_unprepare_complete(clk);
+
 	__clk_unprepare(clk->parent);
 }
 
@@ -842,6 +853,8 @@ int __clk_prepare(struct clk *clk)
 		if (ret)
 			return ret;
 
+		trace_clk_prepare(clk);
+
 		if (clk->ops->prepare) {
 			ret = clk->ops->prepare(clk->hw);
 			if (ret) {
@@ -849,6 +862,8 @@ int __clk_prepare(struct clk *clk)
 				return ret;
 			}
 		}
+
+		trace_clk_prepare_complete(clk);
 	}
 
 	clk->prepare_count++;
@@ -891,9 +906,13 @@ static void __clk_disable(struct clk *clk)
 	if (--clk->enable_count > 0)
 		return;
 
+	trace_clk_disable(clk);
+
 	if (clk->ops->disable)
 		clk->ops->disable(clk->hw);
 
+	trace_clk_disable_complete(clk);
+
 	__clk_disable(clk->parent);
 }
 
@@ -938,6 +957,7 @@ static int __clk_enable(struct clk *clk)
 		if (ret)
 			return ret;
 
+		trace_clk_enable(clk);
 		if (clk->ops->enable) {
 			ret = clk->ops->enable(clk->hw);
 			if (ret) {
@@ -945,6 +965,7 @@ static int __clk_enable(struct clk *clk)
 				return ret;
 			}
 		}
+		trace_clk_enable_complete(clk);
 	}
 
 	clk->enable_count++;
@@ -1241,6 +1262,8 @@ static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent)
 	unsigned long flags;
 	struct clk *old_parent = clk->parent;
 
+	trace_clk_set_parent(clk, parent);
+
 	/*
 	 * Migrate prepare state between parents and prevent race with
 	 * clk_enable().
@@ -1285,6 +1308,7 @@ static void __clk_set_parent_after(struct clk *clk, struct clk *parent,
 		__clk_unprepare(old_parent);
 	}
 
+	trace_clk_set_parent_complete(clk, parent);
 	/* update debugfs with new clk tree topology */
 	clk_debug_reparent(clk, parent);
 }
@@ -1507,6 +1531,8 @@ static void clk_change_rate(struct clk *clk)
 	else if (clk->parent)
 		best_parent_rate = clk->parent->rate;
 
+	trace_clk_set_rate(clk, clk->new_rate);
+
 	if (clk->new_parent && clk->new_parent != clk->parent) {
 		old_parent = __clk_set_parent_before(clk, clk->new_parent);
 
@@ -1525,6 +1551,8 @@ static void clk_change_rate(struct clk *clk)
 	if (!skip_set_rate && clk->ops->set_rate)
 		clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
 
+	trace_clk_set_rate_complete(clk, clk->new_rate);
+
 	clk->rate = clk_recalc(clk, best_parent_rate);
 
 	if (clk->notifier_count && old_rate != clk->rate)
diff --git a/include/trace/events/clk.h b/include/trace/events/clk.h
new file mode 100644
index 000000000000..8523adce0f73
--- /dev/null
+++ b/include/trace/events/clk.h
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM clk
+
+#if !defined(_TRACE_CLK_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_CLK_H
+
+#include <linux/tracepoint.h>
+
+struct clk;
+
+DECLARE_EVENT_CLASS(clk,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk),
+
+	TP_STRUCT__entry(
+		__string(        name,           __clk_get_name(clk)       )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, __clk_get_name(clk));
+	),
+
+	TP_printk("%s", __get_str(name))
+);
+
+DEFINE_EVENT(clk, clk_enable,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_enable_complete,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_disable,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_disable_complete,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_prepare,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_prepare_complete,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_unprepare,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DEFINE_EVENT(clk, clk_unprepare_complete,
+
+	TP_PROTO(struct clk *clk),
+
+	TP_ARGS(clk)
+);
+
+DECLARE_EVENT_CLASS(clk_rate,
+
+	TP_PROTO(struct clk *clk, unsigned long rate),
+
+	TP_ARGS(clk, rate),
+
+	TP_STRUCT__entry(
+		__string(        name,           __clk_get_name(clk)       )
+		__field(unsigned long,           rate                      )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, __clk_get_name(clk));
+		__entry->rate = rate;
+	),
+
+	TP_printk("%s %lu", __get_str(name), (unsigned long)__entry->rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_rate,
+
+	TP_PROTO(struct clk *clk, unsigned long rate),
+
+	TP_ARGS(clk, rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_rate_complete,
+
+	TP_PROTO(struct clk *clk, unsigned long rate),
+
+	TP_ARGS(clk, rate)
+);
+
+DECLARE_EVENT_CLASS(clk_parent,
+
+	TP_PROTO(struct clk *clk, struct clk *parent),
+
+	TP_ARGS(clk, parent),
+
+	TP_STRUCT__entry(
+		__string(        name,           __clk_get_name(clk)       )
+		__string(        pname,          __clk_get_name(parent)    )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, __clk_get_name(clk));
+		__assign_str(pname, __clk_get_name(parent));
+	),
+
+	TP_printk("%s %s", __get_str(name), __get_str(pname))
+);
+
+DEFINE_EVENT(clk_parent, clk_set_parent,
+
+	TP_PROTO(struct clk *clk, struct clk *parent),
+
+	TP_ARGS(clk, parent)
+);
+
+DEFINE_EVENT(clk_parent, clk_set_parent_complete,
+
+	TP_PROTO(struct clk *clk, struct clk *parent),
+
+	TP_ARGS(clk, parent)
+);
+
+#endif /* _TRACE_CLK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
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