[PATCH AUTOSEL 4.19 01/17] clk: imx: Use div64_ul instead of do_div

Sasha Levin sashal at kernel.org
Mon Jan 17 09:05:35 PST 2022


From: Changcheng Deng <deng.changcheng at zte.com.cn>

[ Upstream commit c1b6ad9a902539f9c037b6b3c35cb134c5724022 ]

do_div() does a 64-by-32 division. Here the divisor is an unsigned long
which on some platforms is 64 bit wide. So use div64_ul instead of do_div
to avoid a possible truncation.

Reported-by: Zeal Robot <zealci at zte.com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng at zte.com.cn>
Reviewed-by: Abel Vesa <abel.vesa at nxp.com>
Link: https://lore.kernel.org/r/20211118080634.165275-1-deng.changcheng@zte.com.cn
Signed-off-by: Abel Vesa <abel.vesa at nxp.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/clk/imx/clk-pllv3.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/imx/clk-pllv3.c b/drivers/clk/imx/clk-pllv3.c
index 9af62ee8f347a..325a03e89cf8d 100644
--- a/drivers/clk/imx/clk-pllv3.c
+++ b/drivers/clk/imx/clk-pllv3.c
@@ -252,7 +252,7 @@ static long clk_pllv3_av_round_rate(struct clk_hw *hw, unsigned long rate,
 	div = rate / parent_rate;
 	temp64 = (u64) (rate - div * parent_rate);
 	temp64 *= mfd;
-	do_div(temp64, parent_rate);
+	temp64 = div64_ul(temp64, parent_rate);
 	mfn = temp64;
 
 	temp64 = (u64)parent_rate;
@@ -282,7 +282,7 @@ static int clk_pllv3_av_set_rate(struct clk_hw *hw, unsigned long rate,
 	div = rate / parent_rate;
 	temp64 = (u64) (rate - div * parent_rate);
 	temp64 *= mfd;
-	do_div(temp64, parent_rate);
+	temp64 = div64_ul(temp64, parent_rate);
 	mfn = temp64;
 
 	val = readl_relaxed(pll->base);
@@ -339,7 +339,7 @@ static struct clk_pllv3_vf610_mf clk_pllv3_vf610_rate_to_mf(
 		/* rate = parent_rate * (mfi + mfn/mfd) */
 		temp64 = rate - parent_rate * mf.mfi;
 		temp64 *= mf.mfd;
-		do_div(temp64, parent_rate);
+		temp64 = div64_ul(temp64, parent_rate);
 		mf.mfn = temp64;
 	}
 
-- 
2.34.1




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