From patchwork Fri Jun 16 09:26:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 13282399 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 37C018F57; Fri, 16 Jun 2023 09:26:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05596C433C0; Fri, 16 Jun 2023 09:26:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686907611; bh=tARQMYG/aYeqmMUAJH7cbPA26P2Il2Rzs/1oa9c9qgk=; h=From:To:Cc:Subject:Date:From; b=CCgVGKytISv+fj1viUpOXb/VC4Og1rkCvfO1nGrZGtrr1hcPuZ0OGg72pWvzllRMt B2i720ZfbsqDU3GVRmN6t7ig12mjc3aT0Fo+p3oR10Nv3yAlD4LtPlTSLUYfYeeg3B bGj3FAUqVSldEwRGDSkJ7bujvfySd2/5hftnxzPLC8DhikYfFUna16dmx7UZzUNM4/ 4pn4P/OsmywmiZ6cw+2KCP0P1V1hlCn42pdDJ//LUDJiUgy0ZD3nx8MtrDgqG2SO48 fmE0/zJZ8CLWyI8+9UTPddpKhqr8Ht40TYTI9yS8Kv/T85fISnMtqW5qcGxic477Hd hB3qSJirhs9bQ== From: Arnd Bergmann To: Igor Russkikh , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Arnd Bergmann , Nathan Chancellor , Nick Desaulniers , Tom Rix , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH] net: atlantic: fix ring buffer alignment Date: Fri, 16 Jun 2023 11:26:32 +0200 Message-Id: <20230616092645.3384103-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Arnd Bergmann clang warns about conflicting packing annotations: drivers/net/ethernet/aquantia/atlantic/aq_ring.h:72:2: error: field within 'struct aq_ring_buff_s' is less aligned than 'union aq_ring_buff_s::(anonymous at drivers/net/ethernet/aquantia/atlantic/aq_ring.h:72:2)' and is usually due to 'struct aq_ring_buff_s' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] This was originally intended to ensure the structure fits exactly into 32 bytes on 64-bit architectures, but apparently never did, and instead just produced misaligned pointers as well as forcing byte-wise access on hardware without unaligned load/store instructions. Update the comment to more closely reflect the layout and remove the broken __packed annotation. Signed-off-by: Arnd Bergmann Acked-by: Igor Russkikh --- .../net/ethernet/aquantia/atlantic/aq_ring.h | 26 +++++++++++-------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.h b/drivers/net/ethernet/aquantia/atlantic/aq_ring.h index 0a6c34438c1d0..a9cc5a1c4c479 100644 --- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.h +++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.h @@ -26,19 +26,23 @@ struct aq_rxpage { unsigned int pg_off; }; -/* TxC SOP DX EOP - * +----------+----------+----------+----------- - * 8bytes|len l3,l4 | pa | pa | pa - * +----------+----------+----------+----------- - * 4/8bytes|len pkt |len pkt | | skb - * +----------+----------+----------+----------- - * 4/8bytes|is_gso |len,flags |len |len,is_eop - * +----------+----------+----------+----------- +/* TxC SOP DX EOP RX + * +----------+----------+----------+----------+------- + * 8bytes|len l3,l4 | pa | pa | pa | hash + * +----------+----------+----------+----------+------- + * 4/8bytes|len pkt |len pkt | | skb | page + * +----------+----------+----------+----------+------- + * 4/8bytes|is_gso |len,flags |len |len,is_eop| daddr + * +----------+----------+----------+----------+------- + * 4/8bytes| | | | | order,pgoff + * +----------+----------+----------+----------+------- + * 2bytes | | | | | vlan_rx_tag + * +----------+----------+----------+----------+------- + * 8bytes + flags + * +----------+----------+----------+----------+------- * - * This aq_ring_buff_s doesn't have endianness dependency. - * It is __packed for cache line optimizations. */ -struct __packed aq_ring_buff_s { +struct aq_ring_buff_s { union { /* RX/TX */ dma_addr_t pa;