linux-kernel - [PATCH 2/3] x86/tsc: Use div64_ul instead of do

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Date: Sun, 28 Apr 2024 18:32:15 +0100
From: Jules Irenge <jbi.octave@...il.com>
To: mingo@...hat.com
Cc: tglx@...utronix.de, bp@...en8.de, x86@...nel.org, hpa@...or.com,
	peterz@...radead.org, rdunlap@...radead.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] x86/tsc: Use div64_ul instead of do_div()

do_div() truncates a u64 divisor to 32 bit.
This can lead to non-zero being truncated to zero for division.

Fix coccinelle warning
WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead

Signed-off-by: Jules Irenge <jbi.octave@...il.com>
---
 arch/x86/kernel/tsc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2da37f33dd17..2ed154a2642c 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -823,7 +823,7 @@ static unsigned long pit_hpet_ptimer_calibrate_cpu(void)
 
 		/* Check the reference deviation */
 		delta = ((u64) tsc_pit_min) * 100;
-		do_div(delta, tsc_ref_min);
+		div64_ul(delta, tsc_ref_min);
 
 		/*
 		 * If both calibration results are inside a 10% window
-- 
2.43.2