From patchwork Tue Jun 28 04:15:26 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 12897602 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 608EECCA47F for ; Tue, 28 Jun 2022 04:16:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244112AbiF1EQb (ORCPT ); Tue, 28 Jun 2022 00:16:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243998AbiF1EQR (ORCPT ); Tue, 28 Jun 2022 00:16:17 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C4C82A952; Mon, 27 Jun 2022 21:16:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656389775; x=1687925775; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=7XFdr+eznIKY5BISdchDRGbsYZc1KvPxuDwi55+7zKg=; b=jiRVRQXb6N9Pu2+IGsaD2hrofFEGtlCMnG5Khwy9a2V4jZpbsEmY+N9f 5lhGt7taQPAqLo8Mpa4O27H2vllLvaEDxypcNuJlno94ulNBTi8hh8TlR 3MYCGJgTqmfi20YZx/Fy46gk5Gu/cEV6bqeaIOpWVaCO/Ju3j2FjjThbN aTope/0pybkvc5UmkjtDL3jU0wBh8lNrncYufmfVIgEXbSrHzvaPOnAKu 7SoH2P/p6W31HCNTOWt4cdcnXI8wiwD6NYqhWUBxpvr97puYc/nJ9oRUq kQEbWPVW9Gb6bXspDFUnbhsOji7Y+TRBsNf/3GiR+x3wCLyjTV3yKnb6l Q==; X-IronPort-AV: E=McAfee;i="6400,9594,10391"; a="345627092" X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="345627092" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 21:16:14 -0700 X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="646727887" Received: from nakedgex-mobl.amr.corp.intel.com (HELO localhost) ([10.255.3.161]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 21:16:11 -0700 From: ira.weiny@intel.com To: Dan Williams , Bjorn Helgaas , Jonathan Cameron Cc: Ira Weiny , Ben Widawsky , Alison Schofield , Lukas Wunner , Vishal Verma , Dave Jiang , linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH V12 8/9] cxl/port: Retry reading CDAT on failure Date: Mon, 27 Jun 2022 21:15:26 -0700 Message-Id: <20220628041527.742333-9-ira.weiny@intel.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220628041527.742333-1-ira.weiny@intel.com> References: <20220628041527.742333-1-ira.weiny@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@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 Reviewed-by: Alison Schofield Signed-off-by: Ira Weiny --- 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 | 41 ++++++++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 11 deletions(-) diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c index 6d775cc3dca1..d7c2a415cc5f 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -618,36 +618,30 @@ 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; cdat_mb = find_cdat_mb(uport); if (!cdat_mb) { dev_dbg(dev, "No CDAT mailbox\n"); - return; + return -EIO; } port->cdat_sup = true; if (cxl_cdat_get_length(dev, cdat_mb, &cdat_length)) { dev_dbg(dev, "No CDAT length\n"); - return; + return -EIO; } port->cdat.table = devm_kzalloc(dev, cdat_length, GFP_KERNEL); if (!port->cdat.table) - return; + return -ENOMEM; port->cdat.length = cdat_length; ret = cxl_cdat_read_table(dev, cdat_mb, &port->cdat); @@ -658,5 +652,30 @@ void read_cdat_data(struct cxl_port *port) port->cdat.length = 0; dev_err(dev, "CDAT data read error\n"); } + + 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);