linux-kernel - [PATCH v2] clk: Use div64_ul instead of do

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Message-Id: <20211118082858.165538-1-deng.changcheng@zte.com.cn>
Date:   Thu, 18 Nov 2021 08:28:58 +0000
From:   cgel.zte@...il.com
To:     avifishman70@...il.com
Cc:     benjaminfair@...gle.com, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org, mturquette@...libre.com,
        openbmc@...ts.ozlabs.org, sboyd@...nel.org, tali.perry1@...il.com,
        tmaimon77@...il.com, venture@...gle.com, yuenn@...gle.com,
        zealci@....com.cn, cgel.zte@...il.com, deng.changcheng@....com.cn
Subject: [PATCH v2] clk: Use div64_ul instead of do_div

From: Changcheng Deng <deng.changcheng@....com.cn>

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@....com.cn>
Signed-off-by: Changcheng Deng <deng.changcheng@....com.cn>
---
 drivers/clk/clk-npcm7xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/clk-npcm7xx.c b/drivers/clk/clk-npcm7xx.c
index e677bb5a784b..c75880af2b74 100644
--- a/drivers/clk/clk-npcm7xx.c
+++ b/drivers/clk/clk-npcm7xx.c
@@ -56,7 +56,7 @@ static unsigned long npcm7xx_clk_pll_recalc_rate(struct clk_hw *hw,
 	otdv2 = FIELD_GET(PLLCON_OTDV2, val);
 
 	ret = (u64)parent_rate * fbdv;
-	do_div(ret, indv * otdv1 * otdv2);
+	ret = div64_ul(ret, indv * otdv1 * otdv2);
 
 	return ret;
 }
-- 
2.25.1