[PATCH 6.12 0107/1276] clk: scmi: Fix clock rate rounding

[PATCH 6.12 0107/1276] clk: scmi: Fix clock rate rounding

[Greg Kroah-Hartman]

6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Cristian Marussi <cristian.marussi@arm.com>

[ Upstream commit d0c81a38d06d446d341532700b3a4a43d3b00eb1 ]

While the do_div() helper used for rounding expects its divisor argument
to be a 32bits quantity, the currently provided divisor parameter is a
64bit value that, as a consequence, is silently truncated and a possible
source of bugs.

Fix by using the proper div64_ul helper.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Fixes: 7a8655e19bdb ("clk: scmi: Fix the rounding of clock rate")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Tested-by: Florian Fainelli <florian.fainelli@broadcom.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260508153300.2224715-2-cristian.marussi@arm.com
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clk/clk-scmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index 7b7ea36333a6bc..c0e9db04f450c8 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -10,9 +10,9 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/math64.h>
 #include <linux/module.h>
 #include <linux/scmi_protocol.h>
-#include <asm/div64.h>
 
 #define NOT_ATOMIC	false
 #define ATOMIC		true
@@ -78,7 +78,7 @@ static long scmi_clk_round_rate(struct clk_hw *hw, unsigned long rate,
 
 	ftmp = rate - fmin;
 	ftmp += clk->info->range.step_size - 1; /* to round up */
-	do_div(ftmp, clk->info->range.step_size);
+	ftmp = div64_ul(ftmp, clk->info->range.step_size);
 
 	return ftmp * clk->info->range.step_size + fmin;
 }
-- 
2.53.0