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=-12.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2E518C433F5 for ; Wed, 22 Sep 2021 09:10:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11ED361360 for ; Wed, 22 Sep 2021 09:10:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233792AbhIVJLg (ORCPT ); Wed, 22 Sep 2021 05:11:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:41764 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233741AbhIVJLf (ORCPT ); Wed, 22 Sep 2021 05:11:35 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9F59B6135F; Wed, 22 Sep 2021 09:10:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632301805; bh=Tw+H/INKA6hDKy06eVpzDJMeg1TfBCvc9vMYRHvPtJE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TTDBPIJ5vHvIVJSA22cSleYy4BbTCoJXrAMQ2zY1Rke6IWXw4/Dy3MZfBAqO8ppes HxYHqKCYt3AZQ4PZOwktrStQTvH1VrNppkjw4kPhFzp44dnhIhBf/cA4F8qkppFX/o nLSqk9liTju3ThlNwlUbMAlF1PKwROa3CuWD0u1I= Date: Wed, 22 Sep 2021 11:10:02 +0200 From: Greg Kroah-Hartman To: Chen Yu Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Len Brown , Dan Williams , Andy Shevchenko , Aubrey Li , Ashok Raj , Mike Rapoport , Ard Biesheuvel , Jonathan Corbet , Hans de Goede , Ben Widawsky , linux-doc@vger.kernel.org Subject: Re: [PATCH v3 3/5] drivers/acpi: Introduce Platform Firmware Runtime Update device driver Message-ID: References: <90d270c031401430445cb2c4ba1b9b0c265cf9d4.1631802163.git.yu.c.chen@intel.com> <20210922090442.GA16963@chenyu5-mobl1> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210922090442.GA16963@chenyu5-mobl1> Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Wed, Sep 22, 2021 at 05:04:42PM +0800, Chen Yu wrote: > Hi Greg, > On Tue, Sep 21, 2021 at 05:59:05PM +0200, Greg Kroah-Hartman wrote: > > On Fri, Sep 17, 2021 at 12:02:18AM +0800, Chen Yu wrote: > > > Introduce the pfru_update driver which can be used for Platform Firmware > > > Runtime code injection and driver update. The user is expected to provide > > > the update firmware in the form of capsule file, and pass it to the driver > > > via ioctl. Then the driver would hand this capsule file to the Platform > > > Firmware Runtime Update via the ACPI device _DSM method. At last the low > > > level Management Mode would do the firmware update. > > > > > > Signed-off-by: Chen Yu > > > > Where is the userspace code that uses this ioctl and has tested it out > > to verify it works properly? A link to that in the changelog would be > > great to have. > > > The patch [5/5] is a self testing tool to test the whole feature. I'll send a > new version and Cc you too. That tests it, but does not answer the question of who will actually use this. What userspace tool needs this new api? > > > +static void dump_update_result(struct pfru_updated_result *result) > > > +{ > > > + pr_debug("Update result:\n"); > > > + pr_debug("Status:%d\n", result->status); > > > + pr_debug("Extended Status:%d\n", result->ext_status); > > > + pr_debug("Authentication Time Low:%lld\n", result->low_auth_time); > > > + pr_debug("Authentication Time High:%lld\n", result->high_auth_time); > > > + pr_debug("Execution Time Low:%lld\n", result->low_exec_time); > > > + pr_debug("Execution Time High:%lld\n", result->high_exec_time); > > > > Why not dev_dbg()? Same for all pr_* calls in this "driver". > > > > > Ok, I'll switch to dev_dbg() in next version. > > > +static long pfru_ioctl(struct file *file, unsigned int cmd, unsigned long arg) > > > +{ > > > + void __user *p; > > > + int ret = 0, rev; > > > + > > > + p = (void __user *)arg; > > > + > > > + switch (cmd) { > > > + case PFRU_IOC_SET_REV: > > > + if (copy_from_user(&rev, p, sizeof(unsigned int))) > > > + return -EFAULT; > > > + if (!pfru_valid_revid(rev)) > > > + return -EFAULT; > > > + pfru_dev->rev_id = rev; > > > + break; > > > + case PFRU_IOC_STAGE: > > > + ret = start_acpi_update(START_STAGE); > > > + break; > > > + case PFRU_IOC_ACTIVATE: > > > + ret = start_acpi_update(START_ACTIVATE); > > > + break; > > > + case PFRU_IOC_STAGE_ACTIVATE: > > > + ret = start_acpi_update(START_STAGE_ACTIVATE); > > > + break; > > > + default: > > > + ret = -ENOIOCTLCMD; > > > > Wrong value :( > Previously I thought that ENOIOCTLCMD stands for 'invalid ioctl command'. > After checking the lkml discussion, it seems that ENOIOCTLCMD should not > be returned to user space. ENOTTY might be more suitible if I understand > correctly. > http://lkml.iu.edu/hypermail/linux/kernel/0105.1/0734.html Yes, ENOTTY is correct. > > > + break; > > > + } > > > + > > > + return ret; > > > +} > > > + > > > +#ifdef CONFIG_COMPAT > > > +static long compat_pfru_ioctl(struct file *filep, unsigned int cmd, > > > + unsigned long arg) > > > +{ > > > + return pfru_ioctl(filep, cmd, arg); > > > +} > > > +#endif > > > > Why is this compat ioctl needed at all? > > > We can not control if the user space tool would be compiled as 32bit. Then create your ioctl so that a compat ioctl is not needed at all. There is no need to ever use this for new ioctl commands these days. > But I realize that a compat_ptr() was missing. Will fix it in next version. > > > +static struct miscdevice pfru_misc_dev = { > > > + .minor = MISC_DYNAMIC_MINOR, > > > + .name = "pfru_update", > > > + .nodename = "pfru/update", > > > > Why is this in a subdirectory? What requires this? Why not just > > "pfru"? > > > The pfru directory might be reused for pfru_telemetry device, whose driver > is in 4/5 patch, I'll Cc you with the whole patch set in next version. "might be" is not a valid reason. Why does this simple driver deserve a whole /dev/ subdirectory? thanks, greg k-h