From patchwork Tue Mar 31 08:58:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 228579 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 703BBC2D0EE for ; Tue, 31 Mar 2020 09:20:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4789920658 for ; Tue, 31 Mar 2020 09:20:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585646437; bh=QaVZu7oeE9kvody+R9vApzpKSF+e7ayYBfps5bhprrE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LudqZtHKfiYvZIZAoq03vI6anUrUUPZJQJcWrc+ZV74CGJMoR2v9L/P2bwd8rBNkD 6OVvG7XCVSGub+wpHIW+WwcNdET7Bd9HNbVeS6+owLZZFaLi5xc4XzPij6Vt0KjqeB 6E5wF7tHB2o08WwdX0oDpe0ADpFL0Jwl1RlgkpVI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730704AbgCaJNv (ORCPT ); Tue, 31 Mar 2020 05:13:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:33418 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731345AbgCaJNu (ORCPT ); Tue, 31 Mar 2020 05:13:50 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 71A0D2072E; Tue, 31 Mar 2020 09:13:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585646029; bh=QaVZu7oeE9kvody+R9vApzpKSF+e7ayYBfps5bhprrE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I3sqFM0LjudA3VLCqPKNkq7ExUxghoXTyLznKkAvnn38FUobmHWWkUefxDr8PtIai fCdAM7o/K/n30C2IhvCBy1BCaZS/GcR+PyaouXR9Kn1bbvv3dCMtjJuuj9UGhzfR+j /XlBSFYGdf36HWinvMloPuJzNuvgNPRRHX5vQvo0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Madalin Bucur , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 059/155] dt-bindings: net: FMan erratum A050385 Date: Tue, 31 Mar 2020 10:58:19 +0200 Message-Id: <20200331085425.175656389@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200331085418.274292403@linuxfoundation.org> References: <20200331085418.274292403@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Madalin Bucur [ Upstream commit 26d5bb9e4c4b541c475751e015072eb2cbf70d15 ] FMAN DMA read or writes under heavy traffic load may cause FMAN internal resource leak; thus stopping further packet processing. The FMAN internal queue can overflow when FMAN splits single read or write transactions into multiple smaller transactions such that more than 17 AXI transactions are in flight from FMAN to interconnect. When the FMAN internal queue overflows, it can stall further packet processing. The issue can occur with any one of the following three conditions: 1. FMAN AXI transaction crosses 4K address boundary (Errata A010022) 2. FMAN DMA address for an AXI transaction is not 16 byte aligned, i.e. the last 4 bits of an address are non-zero 3. Scatter Gather (SG) frames have more than one SG buffer in the SG list and any one of the buffers, except the last buffer in the SG list has data size that is not a multiple of 16 bytes, i.e., other than 16, 32, 48, 64, etc. With any one of the above three conditions present, there is likelihood of stalled FMAN packet processing, especially under stress with multiple ports injecting line-rate traffic. To avoid situations that stall FMAN packet processing, all of the above three conditions must be avoided; therefore, configure the system with the following rules: 1. Frame buffers must not span a 4KB address boundary, unless the frame start address is 256 byte aligned 2. All FMAN DMA start addresses (for example, BMAN buffer address, FD[address] + FD[offset]) are 16B aligned 3. SG table and buffer addresses are 16B aligned and the size of SG buffers are multiple of 16 bytes, except for the last SG buffer that can be of any size. Additional workaround notes: - Address alignment of 64 bytes is recommended for maximally efficient system bus transactions (although 16 byte alignment is sufficient to avoid the stall condition) - To support frame sizes that are larger than 4K bytes, there are two options: 1. Large single buffer frames that span a 4KB page boundary can be converted into SG frames to avoid transaction splits at the 4KB boundary, 2. Align the large single buffer to 256B address boundaries, ensure that the frame address plus offset is 256B aligned. - If software generated SG frames have buffers that are unaligned and with random non-multiple of 16 byte lengths, before transmitting such frames via FMAN, frames will need to be copied into a new single buffer or multiple buffer SG frame that is compliant with the three rules listed above. Signed-off-by: Madalin Bucur Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- Documentation/devicetree/bindings/net/fsl-fman.txt | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/net/fsl-fman.txt b/Documentation/devicetree/bindings/net/fsl-fman.txt index 299c0dcd67db4..1316f0aec0cf3 100644 --- a/Documentation/devicetree/bindings/net/fsl-fman.txt +++ b/Documentation/devicetree/bindings/net/fsl-fman.txt @@ -110,6 +110,13 @@ PROPERTIES Usage: required Definition: See soc/fsl/qman.txt and soc/fsl/bman.txt +- fsl,erratum-a050385 + Usage: optional + Value type: boolean + Definition: A boolean property. Indicates the presence of the + erratum A050385 which indicates that DMA transactions that are + split can result in a FMan lock. + ============================================================================= FMan MURAM Node