[PATCH 6/8] counter: stm32-lptimer-cnt: Use container_of instead of struct counter_device::priv

[Uwe Kleine-König]

Using counter->priv is a memory read and so more expensive than
container_of which is only an addition. (In this case even a noop
because the offset is 0.)

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: 0/10 up/down: 0/-140 (-140)
	Function                                     old     new   delta
	stm32_lptim_cnt_read                         272     260     -12
	stm32_lptim_cnt_probe                        528     516     -12
	stm32_lptim_cnt_function_write               420     408     -12
	stm32_lptim_cnt_function_read                184     172     -12
	stm32_lptim_cnt_enable_write                 436     424     -12
	stm32_lptim_cnt_enable_read                  312     300     -12
	stm32_lptim_cnt_ceiling_write                368     356     -12
	stm32_lptim_cnt_ceiling_read                  84      72     -12
	stm32_lptim_cnt_action_read                  388     376     -12
	stm32_lptim_cnt_action_write                 576     544     -32
	Total: Before=6458, After=6318, chg -2.17%

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 drivers/counter/stm32-lptimer-cnt.c | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/counter/stm32-lptimer-cnt.c b/drivers/counter/stm32-lptimer-cnt.c
index 5168833b1fdf..c6eb3071571f 100644
--- a/drivers/counter/stm32-lptimer-cnt.c
+++ b/drivers/counter/stm32-lptimer-cnt.c
@@ -30,6 +30,11 @@ struct stm32_lptim_cnt {
 	bool enabled;
 };
 
+static inline struct stm32_lptim_cnt *stm32_lptim_from_counter(struct counter_device *counter)
+{
+	return container_of(counter, struct stm32_lptim_cnt, counter);
+}
+
 static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
 {
 	u32 val;
@@ -141,7 +146,7 @@ static const enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = {
 static int stm32_lptim_cnt_read(struct counter_device *counter,
 				struct counter_count *count, u64 *val)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 	u32 cnt;
 	int ret;
 
@@ -158,7 +163,7 @@ static int stm32_lptim_cnt_function_read(struct counter_device *counter,
 					 struct counter_count *count,
 					 enum counter_function *function)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 
 	if (!priv->quadrature_mode) {
 		*function = COUNTER_FUNCTION_INCREASE;
@@ -177,7 +182,7 @@ static int stm32_lptim_cnt_function_write(struct counter_device *counter,
 					  struct counter_count *count,
 					  enum counter_function function)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 
 	if (stm32_lptim_is_enabled(priv))
 		return -EBUSY;
@@ -200,7 +205,7 @@ static int stm32_lptim_cnt_enable_read(struct counter_device *counter,
 				       struct counter_count *count,
 				       u8 *enable)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 	int ret;
 
 	ret = stm32_lptim_is_enabled(priv);
@@ -216,7 +221,7 @@ static int stm32_lptim_cnt_enable_write(struct counter_device *counter,
 					struct counter_count *count,
 					u8 enable)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 	int ret;
 
 	/* Check nobody uses the timer, or already disabled/enabled */
@@ -241,7 +246,7 @@ static int stm32_lptim_cnt_ceiling_read(struct counter_device *counter,
 					struct counter_count *count,
 					u64 *ceiling)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 
 	*ceiling = priv->ceiling;
 
@@ -252,7 +257,7 @@ static int stm32_lptim_cnt_ceiling_write(struct counter_device *counter,
 					 struct counter_count *count,
 					 u64 ceiling)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 
 	if (stm32_lptim_is_enabled(priv))
 		return -EBUSY;
@@ -277,7 +282,7 @@ static int stm32_lptim_cnt_action_read(struct counter_device *counter,
 				       struct counter_synapse *synapse,
 				       enum counter_synapse_action *action)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 	enum counter_function function;
 	int err;
 
@@ -321,7 +326,7 @@ static int stm32_lptim_cnt_action_write(struct counter_device *counter,
 					struct counter_synapse *synapse,
 					enum counter_synapse_action action)
 {
-	struct stm32_lptim_cnt *const priv = counter->priv;
+	struct stm32_lptim_cnt *const priv = stm32_lptim_from_counter(counter);
 	enum counter_function function;
 	int err;
 
@@ -438,7 +443,6 @@ static int stm32_lptim_cnt_probe(struct platform_device *pdev)
 	}
 	priv->counter.num_counts = 1;
 	priv->counter.signals = stm32_lptim_cnt_signals;
-	priv->counter.priv = priv;
 
 	platform_set_drvdata(pdev, priv);
 
-- 
2.33.0