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: 0/11 up/down: 0/-132 (-132)
Function old new delta
stm32_timer_cnt_probe 436 424 -12
stm32_count_write 312 300 -12
stm32_count_read 236 224 -12
stm32_count_function_write 492 480 -12
stm32_count_function_read 396 384 -12
stm32_count_enable_write 488 476 -12
stm32_count_enable_read 236 224 -12
stm32_count_direction_read 240 228 -12
stm32_count_ceiling_write 200 188 -12
stm32_count_ceiling_read 236 224 -12
stm32_action_read 492 480 -12
Total: Before=5504, After=5372, chg -2.40%
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
drivers/counter/stm32-timer-cnt.c | 24 ++++++++++++++----------
1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/drivers/counter/stm32-timer-cnt.c b/drivers/counter/stm32-timer-cnt.c
index 0546e932db0c..ac0bea6ce690 100644
--- a/drivers/counter/stm32-timer-cnt.c
+++ b/drivers/counter/stm32-timer-cnt.c
@@ -37,6 +37,11 @@ struct stm32_timer_cnt {
struct stm32_timer_regs bak;
};
+static inline struct stm32_timer_cnt *stm32_count_from_counter(struct counter_device *counter)
+{
+ return container_of(counter, struct stm32_timer_cnt, counter);
+}
+
static const enum counter_function stm32_count_functions[] = {
COUNTER_FUNCTION_INCREASE,
COUNTER_FUNCTION_QUADRATURE_X2_A,
@@ -47,7 +52,7 @@ static const enum counter_function stm32_count_functions[] = {
static int stm32_count_read(struct counter_device *counter,
struct counter_count *count, u64 *val)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 cnt;
regmap_read(priv->regmap, TIM_CNT, &cnt);
@@ -59,7 +64,7 @@ static int stm32_count_read(struct counter_device *counter,
static int stm32_count_write(struct counter_device *counter,
struct counter_count *count, const u64 val)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 ceiling;
regmap_read(priv->regmap, TIM_ARR, &ceiling);
@@ -73,7 +78,7 @@ static int stm32_count_function_read(struct counter_device *counter,
struct counter_count *count,
enum counter_function *function)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 smcr;
regmap_read(priv->regmap, TIM_SMCR, &smcr);
@@ -100,7 +105,7 @@ static int stm32_count_function_write(struct counter_device *counter,
struct counter_count *count,
enum counter_function function)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 cr1, sms;
switch (function) {
@@ -140,7 +145,7 @@ static int stm32_count_direction_read(struct counter_device *counter,
struct counter_count *count,
enum counter_count_direction *direction)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 cr1;
regmap_read(priv->regmap, TIM_CR1, &cr1);
@@ -153,7 +158,7 @@ static int stm32_count_direction_read(struct counter_device *counter,
static int stm32_count_ceiling_read(struct counter_device *counter,
struct counter_count *count, u64 *ceiling)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 arr;
regmap_read(priv->regmap, TIM_ARR, &arr);
@@ -166,7 +171,7 @@ static int stm32_count_ceiling_read(struct counter_device *counter,
static int stm32_count_ceiling_write(struct counter_device *counter,
struct counter_count *count, u64 ceiling)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
if (ceiling > priv->max_arr)
return -ERANGE;
@@ -181,7 +186,7 @@ static int stm32_count_ceiling_write(struct counter_device *counter,
static int stm32_count_enable_read(struct counter_device *counter,
struct counter_count *count, u8 *enable)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 cr1;
regmap_read(priv->regmap, TIM_CR1, &cr1);
@@ -194,7 +199,7 @@ static int stm32_count_enable_read(struct counter_device *counter,
static int stm32_count_enable_write(struct counter_device *counter,
struct counter_count *count, u8 enable)
{
- struct stm32_timer_cnt *const priv = counter->priv;
+ struct stm32_timer_cnt *const priv = stm32_count_from_counter(counter);
u32 cr1;
if (enable) {
@@ -336,7 +341,6 @@ static int stm32_timer_cnt_probe(struct platform_device *pdev)
priv->counter.num_counts = 1;
priv->counter.signals = stm32_signals;
priv->counter.num_signals = ARRAY_SIZE(stm32_signals);
- priv->counter.priv = priv;
platform_set_drvdata(pdev, priv);
--
2.33.0
