[PATCH] spi: use is_power_of_2 instead of hweight32 in spi_nor_write()

[Rasmus Villemoes]

hweight32 is a somewhat expensive way to check for power-of-2. Use the
is_power_of_2 helper, which does the standard and cheap idiom
foo&(foo-1)==0.

add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-96 (-96)
Function                                     old     new   delta
spi_nor_write                                388     292     -96

Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
---
 drivers/mtd/spi/spi-nor-core.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index eb49a6c11c..4076646225 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -1240,11 +1240,8 @@ static int spi_nor_write(struct mtd_info *mtd, loff_t to, size_t len,
 		 * If page_size is a power of two, the offset can be quickly
 		 * calculated with an AND operation. On the other cases we
 		 * need to do a modulus operation (more expensive).
-		 * Power of two numbers have only one bit set and we can use
-		 * the instruction hweight32 to detect if we need to do a
-		 * modulus (do_div()) or not.
 		 */
-		if (hweight32(nor->page_size) == 1) {
+		if (is_power_of_2(nor->page_size)) {
 			page_offset = addr & (nor->page_size - 1);
 		} else {
 			u64 aux = addr;
-- 
2.23.0