From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 B22E5C433ED for ; Mon, 17 May 2021 07:10:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8D349610C9 for ; Mon, 17 May 2021 07:10:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231775AbhEQHLZ (ORCPT ); Mon, 17 May 2021 03:11:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:50658 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229919AbhEQHLY (ORCPT ); Mon, 17 May 2021 03:11:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9030F60E09; Mon, 17 May 2021 07:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621235409; bh=jrTHUzGNqrxv8lufgHRzIQS8dD5Gv0s5cLx7IjzXx80=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=yS7J605bZOhHHkWSihkk1TGaCR4L2ILn2xWmYy1MTJ9oeGXuD2wrPozxeACa085Lg 1AqDBuX/5rpfR/jlARL6S5LBomLu8+TJfOxd+P5M6sc0BaESx65d9tFwwhzkyFmJJh 6KZUTEB+LnzALwy7GtAC41quZEmJZh4h+7XSAvOA= Date: Mon, 17 May 2021 09:10:06 +0200 From: Greg KH To: Moritz Fischer Cc: linux-fpga@vger.kernel.org, moritzf@google.com, Russ Weight , Tom Rix Subject: Re: [PATCH 07/12] fpga: sec-mgr: expose hardware error info Message-ID: References: <20210517023200.52707-1-mdf@kernel.org> <20210517023200.52707-8-mdf@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210517023200.52707-8-mdf@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On Sun, May 16, 2021 at 07:31:55PM -0700, Moritz Fischer wrote: > From: Russ Weight > > Extend the FPGA Security Manager class driver to include > an optional update/hw_errinfo sysfs node that can be used > to retrieve 64 bits of device specific error information > following a secure update failure. > > The underlying driver must provide a get_hw_errinfo() callback > function to enable this feature. This data is treated as > opaque by the class driver. It is left to user-space software > or support personnel to interpret this data. No, you don't provide "opaque" data to userspace, that's a sure way to make it such that no one knows what this data is supposed to be, and so it can not be maintained at all. > > Signed-off-by: Russ Weight > Reviewed-by: Tom Rix > Signed-off-by: Moritz Fischer > --- > .../ABI/testing/sysfs-class-fpga-sec-mgr | 14 +++++++ > drivers/fpga/fpga-sec-mgr.c | 38 +++++++++++++++++++ > include/linux/fpga/fpga-sec-mgr.h | 5 +++ > 3 files changed, 57 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr > index 749f2d4c78d3..f1881ce39c63 100644 > --- a/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr > +++ b/Documentation/ABI/testing/sysfs-class-fpga-sec-mgr > @@ -65,3 +65,17 @@ Description: Read-only. Returns a string describing the failure > idle state. If this file is read while a secure > update is in progress, then the read will fail with > EBUSY. > + > +What: /sys/class/fpga_sec_mgr/fpga_secX/update/hw_errinfo > +Date: June 2021 > +KernelVersion: 5.14 > +Contact: Russ Weight > +Description: Read-only. Returns a 64 bit error value providing > + hardware specific information that may be useful in > + debugging errors that occur during FPGA image updates. > + This file is only visible if the underlying device > + supports it. The hw_errinfo value is only accessible > + when the secure update engine is in the idle state. > + If this file is read while a secure update is in > + progress, then the read will fail with EBUSY. > + Format: "0x%llx". > diff --git a/drivers/fpga/fpga-sec-mgr.c b/drivers/fpga/fpga-sec-mgr.c > index 48950843c2b4..cefe9182c3c3 100644 > --- a/drivers/fpga/fpga-sec-mgr.c > +++ b/drivers/fpga/fpga-sec-mgr.c > @@ -36,10 +36,17 @@ static void fpga_sec_set_error(struct fpga_sec_mgr *smgr, enum fpga_sec_err err_ > smgr->err_code = err_code; > } > > +static void fpga_sec_set_hw_errinfo(struct fpga_sec_mgr *smgr) > +{ > + if (smgr->sops->get_hw_errinfo) > + smgr->hw_errinfo = smgr->sops->get_hw_errinfo(smgr); > +} > + > static void fpga_sec_dev_error(struct fpga_sec_mgr *smgr, > enum fpga_sec_err err_code) > { > fpga_sec_set_error(smgr, err_code); > + fpga_sec_set_hw_errinfo(smgr); > smgr->sops->cancel(smgr); > } > > @@ -221,6 +228,23 @@ error_show(struct device *dev, struct device_attribute *attr, char *buf) > } > static DEVICE_ATTR_RO(error); > > +static ssize_t > +hw_errinfo_show(struct device *dev, struct device_attribute *attr, char *buf) > +{ > + struct fpga_sec_mgr *smgr = to_sec_mgr(dev); > + int ret; > + > + mutex_lock(&smgr->lock); > + if (smgr->progress != FPGA_SEC_PROG_IDLE) > + ret = -EBUSY; Why does the state matter here? greg k-h