From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.tipi-net.de (mail.tipi-net.de [194.13.80.246]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DD82040DFDA; Sat, 28 Mar 2026 20:36:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.13.80.246 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774730207; cv=none; b=b6C0JNJ1RhXKwjfVg74v+h0v7nXVkA9u5ISm+roFJ+gYfnjDBM50q+0JkhOclhfT6TrbFFRkezx6REt2qoUqP2PblxEG2v7CSHYnXqdpp+n4G08RD7qrMg6jb/Vkis8Jcas1aP0ecMFdxkzVR5i6xW7/KJWFnweTbr6UXC/FOlQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774730207; c=relaxed/simple; bh=nIL0XDMlVefhqrVUWMCYBuniRXD307UvHlLbMTelUkM=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=KaSM8f8n9E/rEC5j/905IVn3MlBc9q59vO9gHxbS+Jcx9Gh4VhOuAAR/W5hHy2F9jihngqUeJ4zj6mbIOMP5mynGRqDSo+YmbHJsojKJBD7yVdGjA21S5X8CmohrbuslWlS3O2tZvnjPnmM0n33jlR/B3mJqrUVB/y3j7qfV0SU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de; spf=pass smtp.mailfrom=tipi-net.de; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b=avU0OdIG; arc=none smtp.client-ip=194.13.80.246 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tipi-net.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tipi-net.de header.i=@tipi-net.de header.b="avU0OdIG" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 3038FA5842; Sat, 28 Mar 2026 21:36:18 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1774730182; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=j5ffpPEEKmpVzD289rkZzzPLyWoX4V35qWw/m0tK9D8=; b=avU0OdIGB2HBb557hov0Tu4evt0t6gxr1mT9ezgsErhao5GSH4/B85QCTHHXkEGVZeGCx7 YvAqIYXdPdo3R0xVC55aWwZ2P0H7Kw5kfAIfltJUNAhSQB6cc9lepg0MwBUZqOkoYxtiK5 x+xSMlNFyaGLQVA1X3NtcLex8ftx7eM3zg8ZcRdRb73+GhXvtSDLgatbDhoMFqls6pC0hz oqSkOsaLihvbqxPovXXeOyL4qVoPjaCjP1ANXkeUz1I8eXHOpVONKMfj/LiR6ksUd12zaY BdNJa+rekM19iMOgko1SIduwXsnqQkwxxmb57WqjB+j8M3Df3Xm6M1kAVg+YhQ== Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Sat, 28 Mar 2026 21:36:18 +0100 From: Nicolai Buchwitz To: Jakub Kicinski Cc: netdev@vger.kernel.org, Justin Chen , Simon Horman , Doug Berger , Florian Fainelli , Broadcom internal kernel review list , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Stanislav Fomichev , linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH net-next v4 4/6] net: bcmgenet: add XDP_TX support In-Reply-To: <20260324210342.61b0b5f8@kernel.org> References: <20260323120539.136029-1-nb@tipi-net.de> <20260323120539.136029-5-nb@tipi-net.de> <20260324210342.61b0b5f8@kernel.org> Message-ID: X-Sender: nb@tipi-net.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 On 25.3.2026 05:03, Jakub Kicinski wrote: > On Mon, 23 Mar 2026 13:05:33 +0100 Nicolai Buchwitz wrote: >> Implement XDP_TX using ring 16 (DESC_INDEX), the hardware default >> descriptor ring, dedicated to XDP TX for isolation from SKB TX queues. >> >> Ring 16 gets 32 BDs carved from ring 0's allocation. TX completion is >> piggybacked on RX NAPI poll since ring 16's INTRL2_1 bit collides with >> RX ring 0, similar to how bnxt, ice, and other XDP drivers handle TX >> completion within the RX poll path. >> >> The GENET MAC has TBUF_64B_EN set globally, requiring every TX buffer >> to start with a 64-byte struct status_64 (TSB). For local XDP_TX, the >> TSB is prepended by backing xdp->data into the RSB area (unused after >> BPF execution) and zeroing it. For foreign frames redirected from >> other >> devices, the TSB is written into the xdp_frame headroom. >> >> The page_pool DMA direction is changed from DMA_FROM_DEVICE to >> DMA_BIDIRECTIONAL to allow TX reuse of the existing DMA mapping. > > drivers/net/ethernet/broadcom/genet/bcmgenet.c:2420:27: warning: > variable 'tx_ring' set but not used [-Wunused-but-set-variable] > 2420 | struct bcmgenet_tx_ring *tx_ring; > | ^ Missed during the refactoring (should be part of patch 5). I will address this in the next version of this series. Thanks Nicolai