[PATCH 5.15 224/317] mtd: maps: physmap-core: fix flash size larger than 32-bit

Sasha Levin
2024-03-24T23:38:37Z

From: Baruch Siach <baruch@tkos.co.il>

[ Upstream commit 3884f03edd34887514a0865a80769cd5362d5c3b ]

mtd-ram can potentially be larger than 4GB. get_bitmask_order() uses
fls() that is not guaranteed to work with values larger than 32-bit.
Specifically on aarch64 fls() returns 0 when all 32 LSB bits are clear.
Use fls64() instead.

Fixes: ba32ce95cbd987 ("mtd: maps: Merge gpio-addr-flash.c into physmap-core.c")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/9fbf3664ce00f8b07867f1011834015f21d162a5.1707388458.git.baruch@tkos.co.il
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/mtd/maps/physmap-core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/maps/physmap-core.c b/drivers/mtd/maps/physmap-core.c
index 9ab795f03c546..e5552093585e2 100644
--- a/drivers/mtd/maps/physmap-core.c
+++ b/drivers/mtd/maps/physmap-core.c
@@ -528,7 +528,7 @@ static int physmap_flash_probe(struct platform_device *dev)
if (!info->maps[i].phys)
info->maps[i].phys = res->start;

- info->win_order = get_bitmask_order(resource_size(res)) - 1;
+ info->win_order = fls64(resource_size(res)) - 1;
info->maps[i].size = BIT(info->win_order +
(info->gpios ?
info->gpios->ndescs : 0));
--
2.43.0