[PATCH v2] clk: Add tracepoints for hardware operations

[Stephen Boyd]

It's useful to have tracepoints around operations that change the
hardware state so that we can debug clock hardware performance
and operations. Four 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_{min_,max_}rate{_range}(), phase changing events for
clk_set_phase() and parent changing events for clk_set_parent().

Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---

Changes since v1:
 * Fixed missing trace_*_complete() tracepoints

Note this is based on another patch titled "clk: Missing
set_phase op is an error"

 drivers/clk/clk.c          |  56 ++++++++++---
 include/trace/events/clk.h | 198 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 244 insertions(+), 10 deletions(-)
 create mode 100644 include/trace/events/clk.h

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 670c8c86ce9f..3ffadce9a0c2 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -22,6 +22,9 @@
 #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);
@@ -448,10 +451,12 @@ static void clk_unprepare_unused_subtree(struct clk_core *clk)
 		return;
 
 	if (clk_core_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);
 	}
 }
 
@@ -478,10 +483,12 @@ static void clk_disable_unused_subtree(struct clk_core *clk)
 	 * back to .disable
 	 */
 	if (clk_core_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:
@@ -861,9 +868,12 @@ static void clk_core_unprepare(struct clk_core *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_core_unprepare(clk->parent);
 }
 
@@ -901,12 +911,16 @@ static int clk_core_prepare(struct clk_core *clk)
 		if (ret)
 			return ret;
 
-		if (clk->ops->prepare) {
+		trace_clk_prepare(clk);
+
+		if (clk->ops->prepare)
 			ret = clk->ops->prepare(clk->hw);
-			if (ret) {
-				clk_core_unprepare(clk->parent);
-				return ret;
-			}
+
+		trace_clk_prepare_complete(clk);
+
+		if (ret) {
+			clk_core_unprepare(clk->parent);
+			return ret;
 		}
 	}
 
@@ -953,9 +967,13 @@ static void clk_core_disable(struct clk_core *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_core_disable(clk->parent);
 }
 
@@ -1008,12 +1026,16 @@ static int clk_core_enable(struct clk_core *clk)
 		if (ret)
 			return ret;
 
-		if (clk->ops->enable) {
+		trace_clk_enable(clk);
+
+		if (clk->ops->enable)
 			ret = clk->ops->enable(clk->hw);
-			if (ret) {
-				clk_core_disable(clk->parent);
-				return ret;
-			}
+
+		trace_clk_enable_complete(clk);
+
+		if (ret) {
+			clk_core_disable(clk->parent);
+			return ret;
 		}
 	}
 
@@ -1438,10 +1460,14 @@ static int __clk_set_parent(struct clk_core *clk, struct clk_core *parent,
 
 	old_parent = __clk_set_parent_before(clk, parent);
 
+	trace_clk_set_parent(clk, parent);
+
 	/* change clock input source */
 	if (parent && clk->ops->set_parent)
 		ret = clk->ops->set_parent(clk->hw, p_index);
 
+	trace_clk_set_parent_complete(clk, parent);
+
 	if (ret) {
 		flags = clk_enable_lock();
 		clk_reparent(clk, old_parent);
@@ -1665,6 +1691,7 @@ static void clk_change_rate(struct clk_core *clk)
 
 	if (clk->new_parent && clk->new_parent != clk->parent) {
 		old_parent = __clk_set_parent_before(clk, clk->new_parent);
+		trace_clk_set_parent(clk, clk->new_parent);
 
 		if (clk->ops->set_rate_and_parent) {
 			skip_set_rate = true;
@@ -1675,12 +1702,17 @@ static void clk_change_rate(struct clk_core *clk)
 			clk->ops->set_parent(clk->hw, clk->new_parent_index);
 		}
 
+		trace_clk_set_parent_complete(clk, clk->new_parent);
 		__clk_set_parent_after(clk, clk->new_parent, old_parent);
 	}
 
+	trace_clk_set_rate(clk, clk->new_rate);
+
 	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)
@@ -2083,9 +2115,13 @@ int clk_set_phase(struct clk *clk, int degrees)
 
 	clk_prepare_lock();
 
+	trace_clk_set_phase(clk->core, degrees);
+
 	if (clk->core->ops->set_phase)
 		ret = clk->core->ops->set_phase(clk->core->hw, degrees);
 
+	trace_clk_set_phase_complete(clk->core, degrees);
+
 	if (!ret)
 		clk->core->phase = degrees;
 
diff --git a/include/trace/events/clk.h b/include/trace/events/clk.h
new file mode 100644
index 000000000000..758607226bfd
--- /dev/null
+++ b/include/trace/events/clk.h
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2014-2015, 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_core;
+
+DECLARE_EVENT_CLASS(clk,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name       )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, core->name);
+	),
+
+	TP_printk("%s", __get_str(name))
+);
+
+DEFINE_EVENT(clk, clk_enable,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_enable_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_disable,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_disable_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_prepare,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_prepare_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_unprepare,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DEFINE_EVENT(clk, clk_unprepare_complete,
+
+	TP_PROTO(struct clk_core *core),
+
+	TP_ARGS(core)
+);
+
+DECLARE_EVENT_CLASS(clk_rate,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__field(unsigned long,           rate                      )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, core->name);
+		__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_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate)
+);
+
+DEFINE_EVENT(clk_rate, clk_set_rate_complete,
+
+	TP_PROTO(struct clk_core *core, unsigned long rate),
+
+	TP_ARGS(core, rate)
+);
+
+DECLARE_EVENT_CLASS(clk_parent,
+
+	TP_PROTO(struct clk_core *core, struct clk_core *parent),
+
+	TP_ARGS(core, parent),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__string(        pname,          parent->name              )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, core->name);
+		__assign_str(pname, parent->name);
+	),
+
+	TP_printk("%s %s", __get_str(name), __get_str(pname))
+);
+
+DEFINE_EVENT(clk_parent, clk_set_parent,
+
+	TP_PROTO(struct clk_core *core, struct clk_core *parent),
+
+	TP_ARGS(core, parent)
+);
+
+DEFINE_EVENT(clk_parent, clk_set_parent_complete,
+
+	TP_PROTO(struct clk_core *core, struct clk_core *parent),
+
+	TP_ARGS(core, parent)
+);
+
+DECLARE_EVENT_CLASS(clk_phase,
+
+	TP_PROTO(struct clk_core *core, int phase),
+
+	TP_ARGS(core, phase),
+
+	TP_STRUCT__entry(
+		__string(        name,           core->name                )
+		__field(	  int,           phase                     )
+	),
+
+	TP_fast_assign(
+		__assign_str(name, core->name);
+		__entry->phase = phase;
+	),
+
+	TP_printk("%s %d", __get_str(name), (int)__entry->phase)
+);
+
+DEFINE_EVENT(clk_phase, clk_set_phase,
+
+	TP_PROTO(struct clk_core *core, int phase),
+
+	TP_ARGS(core, phase)
+);
+
+DEFINE_EVENT(clk_phase, clk_set_phase_complete,
+
+	TP_PROTO(struct clk_core *core, int phase),
+
+	TP_ARGS(core, phase)
+);
+
+#endif /* _TRACE_CLK_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
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a Linux Foundation Collaborative Project

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