linux-kernel - [PATCH next 05/14] ixgbevf: Use C test for PAGE_SIZE > IXGBE_MAX_DATA_PER

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Message-Id: <20260121145731.3623-6-david.laight.linux@gmail.com>
Date: Wed, 21 Jan 2026 14:57:22 +0000
From: david.laight.linux@...il.com
To: Nathan Chancellor <nathan@...nel.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Arnd Bergmann <arnd@...db.de>,
	linux-arch@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Yury Norov <yury.norov@...il.com>,
	Lucas De Marchi <lucas.demarchi@...el.com>,
	Jani Nikula <jani.nikula@...el.com>,
	Vincent Mailhol <mailhol.vincent@...adoo.fr>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Kees Cook <keescook@...omium.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Tony Nguyen <anthony.l.nguyen@...el.com>,
	Przemek Kitszel <przemyslaw.kitszel@...el.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	netdev@...r.kernel.org
Cc: David Laight <david.laight.linux@...il.com>
Subject: [PATCH next 05/14] ixgbevf: Use C test for PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD

From: David Laight <david.laight.linux@...il.com>

Compile-time tests being added to BIT() make it an 'integer constant
expression' rather than a pre-processor expression for W=1 builds.

This means BIT() can't be used in pre-processor conditional that
checks 'PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD'.
Change to use a normal 'if' statement, the compiler will optimise
away the unwanted code.

Signed-off-by: David Laight <david.laight.linux@...il.com>
---
 .../net/ethernet/intel/ixgbevf/ixgbevf_main.c   | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index d5ce20f47def..65dd5834d0cf 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -4166,9 +4166,6 @@ static int ixgbevf_xmit_frame_ring(struct sk_buff *skb,
 	u32 tx_flags = 0;
 	u16 count = TXD_USE_COUNT(skb_headlen(skb));
 	struct ixgbevf_ipsec_tx_data ipsec_tx = { 0 };
-#if PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD
-	unsigned short f;
-#endif
 	u8 hdr_len = 0;
 	u8 *dst_mac = skb_header_pointer(skb, 0, 0, NULL);
 
@@ -4183,15 +4180,15 @@ static int ixgbevf_xmit_frame_ring(struct sk_buff *skb,
 	 *       + 1 desc for context descriptor,
 	 * otherwise try next time
 	 */
-#if PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD
-	for (f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
-		skb_frag_t *frag = &skb_shinfo(skb)->frags[f];
+	if (PAGE_SIZE > IXGBE_MAX_DATA_PER_TXD) {
+		for (unsigned int f = 0; f < skb_shinfo(skb)->nr_frags; f++) {
+			skb_frag_t *frag = &skb_shinfo(skb)->frags[f];
 
-		count += TXD_USE_COUNT(skb_frag_size(frag));
+			count += TXD_USE_COUNT(skb_frag_size(frag));
+		}
+	} else {
+		count += skb_shinfo(skb)->nr_frags;
 	}
-#else
-	count += skb_shinfo(skb)->nr_frags;
-#endif
 	if (ixgbevf_maybe_stop_tx(tx_ring, count + 3)) {
 		tx_ring->tx_stats.tx_busy++;
 		return NETDEV_TX_BUSY;
-- 
2.39.5