pwm: lpc18xx-sct: Reduce number of devm memory allocations

Each devm allocations has an overhead of 24 bytes to store the related
struct devres_node additionally to the fragmentation of the allocator.
So allocating 16 struct lpc18xx_pwm_data (which only hold a single int)
adds quite some overhead. Instead put the per-channel data into the
driver data struct and allocate it in one go.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
index 8cc8ae16553cf017d83112a2803a19e66434ccea..6cf02554066c10c396ddfcaab0aecfccbad8b5d7 100644 (file)
--- a/drivers/pwm/pwm-lpc18xx-sct.c
+++ b/drivers/pwm/pwm-lpc18xx-sct.c
@@ -76,6 +76,8 @@
 #define LPC18XX_PWM_EVENT_PERIOD       0
 #define LPC18XX_PWM_EVENT_MAX          16
 
+#define LPC18XX_NUM_PWMS               16
+
 /* SCT conflict resolution */
 enum lpc18xx_pwm_res_action {
        LPC18XX_PWM_RES_NONE,
@@ -101,6 +103,7 @@ struct lpc18xx_pwm_chip {
        unsigned long event_map;
        struct mutex res_lock;
        struct mutex period_lock;
+       struct lpc18xx_pwm_data channeldata[LPC18XX_NUM_PWMS];
 };
 
 static inline struct lpc18xx_pwm_chip *
@@ -370,7 +373,7 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 
        lpc18xx_pwm->chip.dev = &pdev->dev;
        lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops;
-       lpc18xx_pwm->chip.npwm = 16;
+       lpc18xx_pwm->chip.npwm = LPC18XX_NUM_PWMS;
 
        /* SCT counter must be in unify (32 bit) mode */
        lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG,
@@ -400,12 +403,7 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
 
                pwm = &lpc18xx_pwm->chip.pwms[i];
 
-               data = devm_kzalloc(lpc18xx_pwm->dev, sizeof(*data),
-                                   GFP_KERNEL);
-               if (!data) {
-                       ret = -ENOMEM;
-                       goto disable_pwmclk;
-               }
+               data = &lpc18xx_pwm->channeldata[i];
 
                pwm_set_chip_data(pwm, data);
        }