linux-kernel - [PATCH v2 net-next 4/5] net: dpaa: no need to make sure all CPUs receive a corresponding Tx queue

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240713225336.1746343-5-vladimir.oltean@nxp.com>
Date: Sun, 14 Jul 2024 01:53:35 +0300
From: Vladimir Oltean <vladimir.oltean@....com>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>,
	Breno Leitao <leitao@...ian.org>,
	Herbert Xu <herbert@...dor.apana.org.au>,
	Madalin Bucur <madalin.bucur@....com>,
	linux-kernel@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org,
	linux-arm-kernel@...ts.infradead.org,
	Madalin Bucur <madalin.bucur@....nxp.com>
Subject: [PATCH v2 net-next 4/5] net: dpaa: no need to make sure all CPUs receive a corresponding Tx queue

dpaa_fq_setup() iterates through the &priv->dpaa_fq_list elements
allocated by dpaa_alloc_all_fqs(). This includes a call to:

	if (!dpaa_fq_alloc(dev, 0, dpaa_max_num_txqs(), list, FQ_TYPE_TX))
		goto fq_alloc_failed;

which gives us dpaa_max_num_txqs() elements of FQ_TYPE_TX type.

The code block which we are deleting runs after an earlier iteration
through &priv->dpaa_fq_list. So at the end of this iteration (for which
there is no early break), egress_cnt will be unconditionally equal to
dpaa_max_num_txqs().

In other words, dpaa_alloc_all_fqs() has already allocated TX queues for
all possible CPUs and the maximal number of traffic classes, and we've
already iterated once through them all.

The while() condition is dead code, remove it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>
Acked-by: Madalin Bucur <madalin.bucur@....nxp.com>
---
v1->v2: none

 drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index f844c9261571..cfe6b57b1da0 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -989,17 +989,6 @@ static int dpaa_fq_setup(struct dpaa_priv *priv,
 		}
 	}
 
-	 /* Make sure all CPUs receive a corresponding Tx queue. */
-	while (egress_cnt < dpaa_max_num_txqs()) {
-		list_for_each_entry(fq, &priv->dpaa_fq_list, list) {
-			if (fq->fq_type != FQ_TYPE_TX)
-				continue;
-			priv->egress_fqs[egress_cnt++] = &fq->fq_base;
-			if (egress_cnt == dpaa_max_num_txqs())
-				break;
-		}
-	}
-
 	kfree(channels);
 
 	return 0;
-- 
2.34.1