[PATCH v2 01/12] treewide: Use is_power_of_2() from linux/log2.h

[Ana Bobillo <anabobillo3@gmail.com>]

From: Ana Bobillo <anabobillo3@gmail.com>

The btrfs code and the bcm2835_sdhost driver each define their own
is_power_of_2(), which clashes with the one in linux/log2.h once a
header they include brings that in, as include/blk.h does after the next
patch. Drop both and use the common one.

The btrfs copy is the same as the common one. The bcm2835_sdhost copy
takes a u64 and also takes 0 as a power of two; its only caller checks
the block size of a data transfer, which the MMC core never sets to 0,
and the Linux driver it comes from makes the same check with the common
is_power_of_2().

Signed-off-by: Ana Bobillo <anabobillo3@gmail.com>
---
Changes in v2:
- New patch, so that blk.h can use is_power_of_2() from linux/log2.h

 drivers/mmc/bcm2835_sdhost.c | 6 +-----
 fs/btrfs/compat.h            | 6 +-----
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/bcm2835_sdhost.c b/drivers/mmc/bcm2835_sdhost.c
index 720127468d3..eee7e2d43a2 100644
--- a/drivers/mmc/bcm2835_sdhost.c
+++ b/drivers/mmc/bcm2835_sdhost.c
@@ -42,6 +42,7 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
+#include <linux/log2.h>
 #include <linux/sizes.h>
 #include <mach/gpio.h>
 #include <power/regulator.h>
@@ -660,11 +661,6 @@ static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
 	writel(host->mmc->clock / 2, host->ioaddr + SDTOUT);
 }
 
-static inline int is_power_of_2(u64 x)
-{
-	return !(x & (x - 1));
-}
-
 static int bcm2835_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
 			    struct mmc_data *data)
 {
diff --git a/fs/btrfs/compat.h b/fs/btrfs/compat.h
index 4596b9d1dd3..ffeba740eff 100644
--- a/fs/btrfs/compat.h
+++ b/fs/btrfs/compat.h
@@ -4,6 +4,7 @@
 #define __BTRFS_COMPAT_H__
 
 #include <linux/errno.h>
+#include <linux/log2.h>
 #include <fs_internal.h>
 #include <u-boot/uuid.h>
 
@@ -74,9 +75,4 @@ static inline void uuid_unparse(const u8 *uuid, char *out)
 	return uuid_bin_to_str((unsigned char *)uuid, out, 0);
 }
 
-static inline int is_power_of_2(unsigned long n)
-{
-	return (n != 0 && ((n & (n - 1)) == 0));
-}
-
 #endif