linux-kernel - [PATCH v2 5/6] gpio: thunderx: Utilize for_each_set

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Date:   Sun, 26 Apr 2020 00:36:24 +0530
From:   Syed Nayyar Waris <syednwaris@...il.com>
To:     akpm@...ux-foundation.org
Cc:     andriy.shevchenko@...ux.intel.com, vilhelm.gray@...il.com,
        rrichter@...vell.com, linus.walleij@...aro.org,
        bgolaszewski@...libre.com, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v2 5/6] gpio: thunderx: Utilize for_each_set_clump macro

This patch reimplements the thunderx_gpio_set_multiple function in
drivers/gpio/gpio-thunderx.c to use the new for_each_set_clump macro.
Instead of looping for each bank in thunderx_gpio_set_multiple
function, now we can skip bank which is not set and save cycles.

Cc: Robert Richter <rrichter@...vell.com>
Cc: Linus Walleij <linus.walleij@...aro.org>
Cc: Bartosz Golaszewski <bgolaszewski@...libre.com>
Signed-off-by: Syed Nayyar Waris <syednwaris@...il.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@...il.com>
---
Changes in v2:
 - No change.

 drivers/gpio/gpio-thunderx.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-thunderx.c b/drivers/gpio/gpio-thunderx.c
index 9f66dea..74aea25 100644
--- a/drivers/gpio/gpio-thunderx.c
+++ b/drivers/gpio/gpio-thunderx.c
@@ -275,12 +275,16 @@ static void thunderx_gpio_set_multiple(struct gpio_chip *chip,
 				       unsigned long *bits)
 {
 	int bank;
-	u64 set_bits, clear_bits;
+	u64 set_bits, clear_bits, gpio_mask;
+	const unsigned long bank_size = 64;
+	unsigned long offset;
+
 	struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
 
-	for (bank = 0; bank <= chip->ngpio / 64; bank++) {
-		set_bits = bits[bank] & mask[bank];
-		clear_bits = ~bits[bank] & mask[bank];
+	for_each_set_clump(offset, gpio_mask, mask, chip->ngpio, bank_size) {
+		bank = offset / bank_size;
+		set_bits = bits[bank] & gpio_mask;
+		clear_bits = ~bits[bank] & gpio_mask;
 		writeq(set_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET);
 		writeq(clear_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_CLR);
 	}
-- 
2.7.4