linux-kernel - [PATCH net v3] ice: use proper macro for testing bit

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Date: Tue, 18 Jun 2024 13:11:19 +0200
From: Petr Oros <poros@...hat.com>
To: netdev@...r.kernel.org
Cc: ivecera@...hat.com,
	przemyslaw.kitszel@...el.com,
	horms@...nel.org,
	Petr Oros <poros@...hat.com>,
	Alexander Lobakin <aleksander.lobakin@...el.com>,
	Jesse Brandeburg <jesse.brandeburg@...el.com>,
	Tony Nguyen <anthony.l.nguyen@...el.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Eric Joyner <eric.joyner@...el.com>,
	Marcin Domagala <marcinx.domagala@...el.com>,
	intel-wired-lan@...ts.osuosl.org (moderated list:INTEL ETHERNET DRIVERS),
	linux-kernel@...r.kernel.org (open list)
Subject: [PATCH net v3] ice: use proper macro for testing bit

Do not use _test_bit() macro for testing bit. The proper macro for this
is one without underline.

_test_bit() is what test_bit() was prior to const-optimization. It
directly calls arch_test_bit(), i.e. the arch-specific implementation
(or the generic one). It's strictly _internal_ and shouldn't be used
anywhere outside the actual test_bit() macro.

test_bit() is a wrapper which checks whether the bitmap and the bit
number are compile-time constants and if so, it calls the optimized
function which evaluates this call to a compile-time constant as well.
If either of them is not a compile-time constant, it just calls _test_bit().
test_bit() is the actual function to use anywhere in the kernel.

IOW, calling _test_bit() avoids potential compile-time optimizations.

The sensors is not a compile-time constant, thus most probably there
are no object code changes before and after the patch.
But anyway, we shouldn't call internal wrappers instead of
the actual API.

Fixes: 4da71a77fc3b ("ice: read internal temperature sensor")
Acked-by: Ivan Vecera <ivecera@...hat.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@...el.com>
Signed-off-by: Petr Oros <poros@...hat.com>
---
 drivers/net/ethernet/intel/ice/ice_hwmon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_hwmon.c b/drivers/net/ethernet/intel/ice/ice_hwmon.c
index e4c2c1bff6c086..b7aa6812510a4f 100644
--- a/drivers/net/ethernet/intel/ice/ice_hwmon.c
+++ b/drivers/net/ethernet/intel/ice/ice_hwmon.c
@@ -96,7 +96,7 @@ static bool ice_is_internal_reading_supported(struct ice_pf *pf)

 	unsigned long sensors = pf->hw.dev_caps.supported_sensors;

-	return _test_bit(ICE_SENSOR_SUPPORT_E810_INT_TEMP_BIT, &sensors);
+	return test_bit(ICE_SENSOR_SUPPORT_E810_INT_TEMP_BIT, &sensors);
 };

 void ice_hwmon_init(struct ice_pf *pf)
-- 
2.44.2