Input: use for_each_set_bit() where appropriate

Instead of iterating over all bits in a bitmap and test them individually
let's siwtch to for_each_set_bit() which is more compact and is also
faster.

Also use bitmap_weight() when counting number of set bits.

This also fixes INPUT_DO_TOGGLE() implementation as it should have used
*_CNT as the upper boundary, not *_MAX.
Signed-off-by: Anshul Garg <aksgarg1989@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/input.c

@@ -677,12 +677,9 @@ static void input_dev_release_keys(struct input_dev *dev)
 	int code;
 
 	if (is_event_supported(EV_KEY, dev->evbit, EV_MAX)) {
-		for (code = 0; code <= KEY_MAX; code++) {
-			if (is_event_supported(code, dev->keybit, KEY_MAX) &&
-			    __test_and_clear_bit(code, dev->key)) {
+		for_each_set_bit(code, dev->key, KEY_CNT)
 			input_pass_event(dev, EV_KEY, code, 0);
-			}
-		}
+		memset(dev->key, 0, sizeof(dev->key));
 		input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 	}
 }
@@ -1626,10 +1623,7 @@ static int input_dev_uevent(struct device *device, struct kobj_uevent_env *env)
 		if (!test_bit(EV_##type, dev->evbit))			\
 			break;						\
 									\
-		for (i = 0; i < type##_MAX; i++) {			\
-			if (!test_bit(i, dev->bits##bit))		\
-				continue;				\
-									\
+		for_each_set_bit(i, dev->bits##bit, type##_CNT) {	\
 			active = test_bit(i, dev->bits);		\
 			if (!active && !on)				\
 				continue;				\
@@ -1980,22 +1974,12 @@ static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
 
 	events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
 
-	if (test_bit(EV_ABS, dev->evbit)) {
-		for (i = 0; i < ABS_CNT; i++) {
-			if (test_bit(i, dev->absbit)) {
-				if (input_is_mt_axis(i))
-					events += mt_slots;
-				else
-					events++;
-			}
-		}
-	}
+	if (test_bit(EV_ABS, dev->evbit))
+		for_each_set_bit(i, dev->absbit, ABS_CNT)
+			events += input_is_mt_axis(i) ? mt_slots : 1;
 
-	if (test_bit(EV_REL, dev->evbit)) {
-		for (i = 0; i < REL_CNT; i++)
-			if (test_bit(i, dev->relbit))
-				events++;
-	}
+	if (test_bit(EV_REL, dev->evbit))
+		events += bitmap_weight(dev->relbit, REL_CNT);
 
 	/* Make room for KEY and MSC events */
 	events += 7;