From patchwork Thu Feb 4 21:27:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russ Weight X-Patchwork-Id: 12068819 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 20F2BC433E0 for ; Thu, 4 Feb 2021 21:28:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D69C164DD6 for ; Thu, 4 Feb 2021 21:28:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229611AbhBDV2D (ORCPT ); Thu, 4 Feb 2021 16:28:03 -0500 Received: from mga01.intel.com ([192.55.52.88]:57877 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229513AbhBDV2D (ORCPT ); Thu, 4 Feb 2021 16:28:03 -0500 IronPort-SDR: klbbzmHJ/8ZnrIMWRIyj1Z3H0cFqtsxuILBG7UFZlKDqP12ZjyS9ypyqzU7Y3w/oO59J/R7md6 ymjZSCOjBUUA== X-IronPort-AV: E=McAfee;i="6000,8403,9885"; a="200325995" X-IronPort-AV: E=Sophos;i="5.81,153,1610438400"; d="scan'208";a="200325995" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 13:27:22 -0800 IronPort-SDR: KCbcfCsMnlaaqAjH1wFixLnEqDQ67GXnHCIqUamMop0TkX0cpx1LsI4xKJkpZBcfO2TKIAnx5e 9p1eSSLd8R+Q== X-IronPort-AV: E=Sophos;i="5.81,153,1610438400"; d="scan'208";a="373134751" Received: from rhweight-mobl2.amr.corp.intel.com (HELO rhweight-mobl2.ra.intel.com) ([10.209.87.127]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Feb 2021 13:27:22 -0800 From: Russ Weight To: mdf@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org Cc: trix@redhat.com, lgoncalv@redhat.com, yilun.xu@intel.com, hao.wu@intel.com, matthew.gerlach@intel.com, Russ Weight Subject: [PATCH v4 1/1] fpga: dfl: afu: harden port enable logic Date: Thu, 4 Feb 2021 13:27:13 -0800 Message-Id: <20210204212713.256021-1-russell.h.weight@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org Port enable is not complete until ACK = 0. Change __afu_port_enable() to guarantee that the enable process is complete by polling for ACK == 0. Reviewed-by: Tom Rix Signed-off-by: Russ Weight Reviewed-by: Matthew Gerlach --- v4: - Added a dev_warn() call for the -EINVAL case of afu_port_err_clear() - Modified dev_err() message in __afu_port_disable() to say "disable" instead of "reset" v3: - afu_port_err_clear() changed to prioritize port_enable failure over other a detected mismatch in port errors. - reorganized code in port_reset() to be more readable. v2: - Fixed typo in commit message --- drivers/fpga/dfl-afu-error.c | 10 ++++++---- drivers/fpga/dfl-afu-main.c | 33 +++++++++++++++++++++++---------- drivers/fpga/dfl-afu.h | 2 +- 3 files changed, 30 insertions(+), 15 deletions(-) diff --git a/drivers/fpga/dfl-afu-error.c b/drivers/fpga/dfl-afu-error.c index c4691187cca9..601e599fc33d 100644 --- a/drivers/fpga/dfl-afu-error.c +++ b/drivers/fpga/dfl-afu-error.c @@ -52,7 +52,7 @@ static int afu_port_err_clear(struct device *dev, u64 err) struct dfl_feature_platform_data *pdata = dev_get_platdata(dev); struct platform_device *pdev = to_platform_device(dev); void __iomem *base_err, *base_hdr; - int ret = -EBUSY; + int enable_ret = 0, ret = -EBUSY; u64 v; base_err = dfl_get_feature_ioaddr_by_id(dev, PORT_FEATURE_ID_ERROR); @@ -96,18 +96,20 @@ static int afu_port_err_clear(struct device *dev, u64 err) v = readq(base_err + PORT_FIRST_ERROR); writeq(v, base_err + PORT_FIRST_ERROR); } else { + dev_warn(dev, "__func__: received 0x%llx, expected 0x%llx\n", + v, err); ret = -EINVAL; } /* Clear mask */ __afu_port_err_mask(dev, false); - /* Enable the Port by clear the reset */ - __afu_port_enable(pdev); + /* Enable the Port by clearing the reset */ + enable_ret = __afu_port_enable(pdev); done: mutex_unlock(&pdata->lock); - return ret; + return enable_ret ? enable_ret : ret; } static ssize_t errors_show(struct device *dev, struct device_attribute *attr, diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c index 753cda4b2568..77dadaae5b8f 100644 --- a/drivers/fpga/dfl-afu-main.c +++ b/drivers/fpga/dfl-afu-main.c @@ -21,6 +21,9 @@ #include "dfl-afu.h" +#define RST_POLL_INVL 10 /* us */ +#define RST_POLL_TIMEOUT 1000 /* us */ + /** * __afu_port_enable - enable a port by clear reset * @pdev: port platform device. @@ -32,7 +35,7 @@ * * The caller needs to hold lock for protection. */ -void __afu_port_enable(struct platform_device *pdev) +int __afu_port_enable(struct platform_device *pdev) { struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); void __iomem *base; @@ -41,7 +44,7 @@ void __afu_port_enable(struct platform_device *pdev) WARN_ON(!pdata->disable_count); if (--pdata->disable_count != 0) - return; + return 0; base = dfl_get_feature_ioaddr_by_id(&pdev->dev, PORT_FEATURE_ID_HEADER); @@ -49,10 +52,20 @@ void __afu_port_enable(struct platform_device *pdev) v = readq(base + PORT_HDR_CTRL); v &= ~PORT_CTRL_SFTRST; writeq(v, base + PORT_HDR_CTRL); -} -#define RST_POLL_INVL 10 /* us */ -#define RST_POLL_TIMEOUT 1000 /* us */ + /* + * HW clears the ack bit to indicate that the port is fully out + * of reset. + */ + if (readq_poll_timeout(base + PORT_HDR_CTRL, v, + !(v & PORT_CTRL_SFTRST_ACK), + RST_POLL_INVL, RST_POLL_TIMEOUT)) { + dev_err(&pdev->dev, "timeout, failure to enable device\n"); + return -ETIMEDOUT; + } + + return 0; +} /** * __afu_port_disable - disable a port by hold reset @@ -86,7 +99,7 @@ int __afu_port_disable(struct platform_device *pdev) if (readq_poll_timeout(base + PORT_HDR_CTRL, v, v & PORT_CTRL_SFTRST_ACK, RST_POLL_INVL, RST_POLL_TIMEOUT)) { - dev_err(&pdev->dev, "timeout, fail to reset device\n"); + dev_err(&pdev->dev, "timeout, failure to disable device\n"); return -ETIMEDOUT; } @@ -111,9 +124,9 @@ static int __port_reset(struct platform_device *pdev) ret = __afu_port_disable(pdev); if (!ret) - __afu_port_enable(pdev); + return ret; - return ret; + return __afu_port_enable(pdev); } static int port_reset(struct platform_device *pdev) @@ -872,11 +885,11 @@ static int afu_dev_destroy(struct platform_device *pdev) static int port_enable_set(struct platform_device *pdev, bool enable) { struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); - int ret = 0; + int ret; mutex_lock(&pdata->lock); if (enable) - __afu_port_enable(pdev); + ret = __afu_port_enable(pdev); else ret = __afu_port_disable(pdev); mutex_unlock(&pdata->lock); diff --git a/drivers/fpga/dfl-afu.h b/drivers/fpga/dfl-afu.h index 576e94960086..e5020e2b1f3d 100644 --- a/drivers/fpga/dfl-afu.h +++ b/drivers/fpga/dfl-afu.h @@ -80,7 +80,7 @@ struct dfl_afu { }; /* hold pdata->lock when call __afu_port_enable/disable */ -void __afu_port_enable(struct platform_device *pdev); +int __afu_port_enable(struct platform_device *pdev); int __afu_port_disable(struct platform_device *pdev); void afu_mmio_region_init(struct dfl_feature_platform_data *pdata);