From patchwork Fri Jun 10 20:22:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 12878086 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0146CCA481 for ; Fri, 10 Jun 2022 20:23:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350662AbiFJUXs (ORCPT ); Fri, 10 Jun 2022 16:23:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350650AbiFJUXM (ORCPT ); Fri, 10 Jun 2022 16:23:12 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5735E2A97F; Fri, 10 Jun 2022 13:23:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1654892591; x=1686428591; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=4p2mctKPaIflcK+x1MadV6MB5YwRUZ8n0NuOLocL9vY=; b=KidfmEIT8xIcM4WPl6MnN50D6ct3VQmw0VxDTyV/FR1FfPKWs7AWyqZj erbhH3p3uQp7QWL75Ze0Kaw4r4sDfQ4eRhx2KcDrK0/oFeDGaduPGOkVG XqS55JWxlJUn7WWclFxUiUSmsX8GAElq3mQdZAePKANkv4h0fs1Rpw+n5 T3yU+EsQi+HJLeFSn+ZRlBrgRegUNoltY2QAnhK/XL86MoicsuCLLd/DK CaES8vb/KfAU+XcVp2kBEHXKxBWgajt6HIQ4EX/03kGHyecU6ODh7R0cG eERjuZnIooh291VhaOeLe3A0FQmHuk0bndni8tzlEQDxtRg8dyVHVZxqy Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10374"; a="278871133" X-IronPort-AV: E=Sophos;i="5.91,291,1647327600"; d="scan'208";a="278871133" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2022 13:23:10 -0700 X-IronPort-AV: E=Sophos;i="5.91,291,1647327600"; d="scan'208";a="566990423" Received: from pleung-mobl1.amr.corp.intel.com (HELO localhost) ([10.212.33.34]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2022 13:23:09 -0700 From: ira.weiny@intel.com To: Dan Williams , Bjorn Helgaas , Jonathan Cameron Cc: Ira Weiny , Ben Widawsky , Alison Schofield , Vishal Verma , Dave Jiang , linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH V11 7/8] cxl/port: Retry reading CDAT on failure Date: Fri, 10 Jun 2022 13:22:58 -0700 Message-Id: <20220610202259.3544623-8-ira.weiny@intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220610202259.3544623-1-ira.weiny@intel.com> References: <20220610202259.3544623-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org From: Ira Weiny The CDAT read may fail for a number of reasons but mainly it is possible to get different parts of a valid state. The checksum in the CDAT table protects against this. Now that the cdat data is validated, issue a retry if the CDAT read fails. For now 5 retries are implemented. Reviewed-by: Ben Widawsky Signed-off-by: Ira Weiny Reviewed-by: Alison Schofield --- Changes from V10 Pick up review tag and fix commit message Changes from V9 Alison Schofield/Davidlohr Bueso Print debug on each iteration and error only after failure Changes from V8 Move code to cxl/core/pci.c Changes from V6 Move to pci.c Fix retries count Change to 5 retries Changes from V5: New patch -- easy to push off or drop. --- drivers/cxl/core/pci.c | 40 +++++++++++++++++++++++++++++++--------- 1 file changed, 31 insertions(+), 9 deletions(-) diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index cb70287e2984..fd02bc7c0d97 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -617,19 +617,13 @@ static int cxl_cdat_read_table(struct device *dev, return rc; } -/** - * read_cdat_data - Read the CDAT data on this port - * @port: Port to read data from - * - * This call will sleep waiting for responses from the DOE mailbox. - */ -void read_cdat_data(struct cxl_port *port) +static int __read_cdat_data(struct cxl_port *port) { static struct pci_doe_mb *cdat_mb; struct device *dev = &port->dev; struct device *uport = port->uport; size_t cdat_length; - int ret; + int ret = 0; /* * Ensure a reference on the underlying uport device which has the @@ -640,17 +634,21 @@ void read_cdat_data(struct cxl_port *port) cdat_mb = find_cdat_mb(uport); if (!cdat_mb) { dev_dbg(dev, "No CDAT mailbox\n"); + ret = -EIO; goto out; } if (cxl_cdat_get_length(dev, cdat_mb, &cdat_length)) { dev_dbg(dev, "No CDAT length\n"); + ret = -EIO; goto out; } port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL); - if (!port->cdat.table) + if (!port->cdat.table) { + ret = -ENOMEM; goto out; + } port->cdat.length = cdat_length; ret = cxl_cdat_read_table(dev, cdat_mb, &port->cdat); @@ -664,5 +662,29 @@ void read_cdat_data(struct cxl_port *port) out: put_device(uport); + return ret; +} + +/** + * read_cdat_data - Read the CDAT data on this port + * @port: Port to read data from + * + * This call will sleep waiting for responses from the DOE mailbox. + */ +void read_cdat_data(struct cxl_port *port) +{ + int retries = 5; + int rc; + + while (retries--) { + rc = __read_cdat_data(port); + if (!rc) + return; + dev_dbg(&port->dev, + "CDAT data read error rc=%d (retries %d)\n", + rc, retries); + } + dev_err(&port->dev, "CDAT data read failed after %d retries\n", + retries); } EXPORT_SYMBOL_NS_GPL(read_cdat_data, CXL);