linux-kernel - [PATCH 10/17] net: ethernet: oa_tc6: Replace open-coded parity calculation with parity32()

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Message-Id: <20250223164217.2139331-11-visitorckw@gmail.com>
Date: Mon, 24 Feb 2025 00:42:10 +0800
From: Kuan-Wei Chiu <visitorckw@...il.com>
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	Kuan-Wei Chiu <visitorckw@...il.com>,
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Subject: [PATCH 10/17] net: ethernet: oa_tc6: Replace open-coded parity calculation with parity32()

Refactor parity calculations to use the standard parity32() helper.
This change eliminates redundant implementations and improves code
efficiency.

Co-developed-by: Yu-Chun Lin <eleanor15x@...il.com>
Signed-off-by: Yu-Chun Lin <eleanor15x@...il.com>
Signed-off-by: Kuan-Wei Chiu <visitorckw@...il.com>
---
 drivers/net/ethernet/oa_tc6.c | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index db200e4ec284..f02dba7b89a1 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/bitfield.h>
+#include <linux/bitops.h>
 #include <linux/iopoll.h>
 #include <linux/mdio.h>
 #include <linux/phy.h>
@@ -177,19 +178,6 @@ static int oa_tc6_spi_transfer(struct oa_tc6 *tc6,
 	return spi_sync(tc6->spi, &msg);
 }
 
-static int oa_tc6_get_parity(u32 p)
-{
-	/* Public domain code snippet, lifted from
-	 * http://www-graphics.stanford.edu/~seander/bithacks.html
-	 */
-	p ^= p >> 1;
-	p ^= p >> 2;
-	p = (p & 0x11111111U) * 0x11111111U;
-
-	/* Odd parity is used here */
-	return !((p >> 28) & 1);
-}
-
 static __be32 oa_tc6_prepare_ctrl_header(u32 addr, u8 length,
 					 enum oa_tc6_register_op reg_op)
 {
@@ -202,7 +190,7 @@ static __be32 oa_tc6_prepare_ctrl_header(u32 addr, u8 length,
 		 FIELD_PREP(OA_TC6_CTRL_HEADER_ADDR, addr) |
 		 FIELD_PREP(OA_TC6_CTRL_HEADER_LENGTH, length - 1);
 	header |= FIELD_PREP(OA_TC6_CTRL_HEADER_PARITY,
-			     oa_tc6_get_parity(header));
+			     !parity32(header));
 
 	return cpu_to_be32(header);
 }
@@ -940,8 +928,7 @@ static __be32 oa_tc6_prepare_data_header(bool data_valid, bool start_valid,
 		     FIELD_PREP(OA_TC6_DATA_HEADER_END_BYTE_OFFSET,
 				end_byte_offset);
 
-	header |= FIELD_PREP(OA_TC6_DATA_HEADER_PARITY,
-			     oa_tc6_get_parity(header));
+	header |= FIELD_PREP(OA_TC6_DATA_HEADER_PARITY, !parity32(header));
 
 	return cpu_to_be32(header);
 }
-- 
2.34.1