linux-kernel - [PATCH 5/8] counter: microchip-tcp-capture: Use container_of instead of struct counter

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Message-Id: <20211221104546.214066-6-u.kleine-koenig@pengutronix.de>
Date:   Tue, 21 Dec 2021 11:45:43 +0100
From:   Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
To:     Kamel Bouhara <kamel.bouhara@...tlin.com>,
        William Breathitt Gray <vilhelm.gray@...il.com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-iio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 5/8] counter: microchip-tcp-capture: Use container_of instead of struct counter_device::priv

Using counter->priv is a memory read and so more expensive than
container_of which is only an addition.

So container_of is expected to be a tad faster, it's type-safe, and
produces smaller code (ARCH=arm allmodconfig):

	add/remove: 0/0 grow/shrink: 1/6 up/down: 12/-68 (-56)
	Function                                     old     new   delta
	mchp_tc_count_function_write                1016    1028     +12
	mchp_tc_count_action_write                   204     196      -8
	mchp_tc_probe                               1376    1364     -12
	mchp_tc_count_signal_read                    360     348     -12
	mchp_tc_count_read                           264     252     -12
	mchp_tc_count_function_read                  108      96     -12
	mchp_tc_count_action_read                    392     380     -12
	Total: Before=5920, After=5864, chg -0.95%

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
---
 drivers/counter/microchip-tcb-capture.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/counter/microchip-tcb-capture.c b/drivers/counter/microchip-tcb-capture.c
index 0ab1b2716784..031e79f5f06a 100644
--- a/drivers/counter/microchip-tcb-capture.c
+++ b/drivers/counter/microchip-tcb-capture.c
@@ -32,6 +32,11 @@ struct mchp_tc_data {
 	bool trig_inverted;
 };
 
+static inline struct mchp_tc_data *mchp_tc_from_counter(struct counter_device *counter)
+{
+	return container_of(counter, struct mchp_tc_data, counter);
+}
+
 static const enum counter_function mchp_tc_count_functions[] = {
 	COUNTER_FUNCTION_INCREASE,
 	COUNTER_FUNCTION_QUADRATURE_X4,
@@ -72,7 +77,7 @@ static int mchp_tc_count_function_read(struct counter_device *counter,
 				       struct counter_count *count,
 				       enum counter_function *function)
 {
-	struct mchp_tc_data *const priv = counter->priv;
+	struct mchp_tc_data *const priv = mchp_tc_from_counter(counter);
 
 	if (priv->qdec_mode)
 		*function = COUNTER_FUNCTION_QUADRATURE_X4;
@@ -86,7 +91,7 @@ static int mchp_tc_count_function_write(struct counter_device *counter,
 					struct counter_count *count,
 					enum counter_function function)
 {
-	struct mchp_tc_data *const priv = counter->priv;
+	struct mchp_tc_data *const priv = mchp_tc_from_counter(counter);
 	u32 bmr, cmr;
 
 	regmap_read(priv->regmap, ATMEL_TC_BMR, &bmr);
@@ -148,7 +153,7 @@ static int mchp_tc_count_signal_read(struct counter_device *counter,
 				     struct counter_signal *signal,
 				     enum counter_signal_level *lvl)
 {
-	struct mchp_tc_data *const priv = counter->priv;
+	struct mchp_tc_data *const priv = mchp_tc_from_counter(counter);
 	bool sigstatus;
 	u32 sr;
 
@@ -169,7 +174,7 @@ static int mchp_tc_count_action_read(struct counter_device *counter,
 				     struct counter_synapse *synapse,
 				     enum counter_synapse_action *action)
 {
-	struct mchp_tc_data *const priv = counter->priv;
+	struct mchp_tc_data *const priv = mchp_tc_from_counter(counter);
 	u32 cmr;
 
 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr);
@@ -197,7 +202,7 @@ static int mchp_tc_count_action_write(struct counter_device *counter,
 				      struct counter_synapse *synapse,
 				      enum counter_synapse_action action)
 {
-	struct mchp_tc_data *const priv = counter->priv;
+	struct mchp_tc_data *const priv = mchp_tc_from_counter(counter);
 	u32 edge = ATMEL_TC_ETRGEDG_NONE;
 
 	/* QDEC mode is rising edge only */
@@ -230,7 +235,7 @@ static int mchp_tc_count_action_write(struct counter_device *counter,
 static int mchp_tc_count_read(struct counter_device *counter,
 			      struct counter_count *count, u64 *val)
 {
-	struct mchp_tc_data *const priv = counter->priv;
+	struct mchp_tc_data *const priv = mchp_tc_from_counter(counter);
 	u32 cnt;
 
 	regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt);
@@ -369,7 +374,6 @@ static int mchp_tc_probe(struct platform_device *pdev)
 	priv->counter.counts = mchp_tc_counts;
 	priv->counter.num_signals = ARRAY_SIZE(mchp_tc_count_signals);
 	priv->counter.signals = mchp_tc_count_signals;
-	priv->counter.priv = priv;
 
 	return devm_counter_register(&pdev->dev, &priv->counter);
 }
-- 
2.33.0