From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4118B4CCDEB; Mon, 21 Sep 2026 16:19:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790007600; cv=none; b=JzfDMCf0kCfxoBlccFVZJY69RzfwcqVva+aBkxK4eSC7BoltjtRz62ovYtzhISwch7O7TXYHoj7rlMy6vz5MaFGJBqZVmQ//M5w5dV6tpkwQRJcp7RmRYUPgyw9+q9vuhRAZYbI1XexljT028Tc09c06MecT1e1+nEDC6pkUe+k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790007600; c=relaxed/simple; bh=Nh1o0940wrAZdAacHUvfMALeek9wgBGDKWVVWXx4B40=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ST06ng7mLEIyoXMT/f0CXZFUtnLzPZgD907gQc1vRh/tkrt1yi0HVasir+sDbTC4rJsCdGOvkSyvKDJq9rQBgPF/Qkh5zf3JdUIQbHpVvrwWdQMh2URr827oxwmkEf+atGIz4bRig27GQDiDJr2ODMjB8UK64yl4N15zgFFDYnY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UbxK2uxU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UbxK2uxU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FA1D1F00893; Mon, 21 Sep 2026 16:19:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790007598; bh=yUk6xrHyMi4gFz7Q2nWEkOHH5s2Hu2ne+l7Vi+ljp6Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=UbxK2uxURejDJlalyThSRTeTHPax9jSfShPdzCRZkP3u0RZSL8ufyoda7eOKicwe8 A6vKtma1Z4LdM6+QhHs2KhURVQw/tQweIBomV0Fs0bIxphqHuqdBdXTH6uj89tQocL QmEawNd3P4dx1hmF2HM1b2KwGFi7NihQpZZ4x/+VT8vNVTVnWrDKAKXogwLjhJV5pv XEV+9G4BACeyxqQh1+IIFCDVF8Cx/+xCnMajPrKrlZrazEdt3drIXiGv21VItc1Uek QjDuJj4USMvKbR2MO0l6ymVn/GNsoa5SsO39JaNz86/hs3yczaiN+IweshvtnjgRVU Ots9izkGZaPtw== Date: Mon, 21 Sep 2026 17:19:53 +0100 From: Sudeep Holla To: Andre Przywara Cc: Mark Rutland , Lorenzo Pieralisi , Salman Nabi , Vedashree Vidwans , Trilok Soni , Nirmoy Das , vsethi@nvidia.com, Varun Wadekar , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org Subject: Re: [PATCH v4 8/8] firmware: smccc: lfa: add sysfs ABI documentation Message-ID: <20260921-essential-inquisitive-spaniel-9801eb@sudeepholla> References: <20260918141112.2115555-1-andre.przywara@arm.com> <20260918141112.2115555-9-andre.przywara@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260918141112.2115555-9-andre.przywara@arm.com> On Fri, Sep 18, 2026 at 04:11:11PM +0200, Andre Przywara wrote: > Document the sysfs attribute files as exported by the LFA driver. > Looking at the sysfs output in 2/8 message log, activation_pending is missing from the documentation. > Signed-off-by: Andre Przywara > --- > Documentation/ABI/testing/sysfs-firmware-lfa | 106 +++++++++++++++++++ > 1 file changed, 106 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-firmware-lfa > > diff --git a/Documentation/ABI/testing/sysfs-firmware-lfa b/Documentation/ABI/testing/sysfs-firmware-lfa > new file mode 100644 > index 0000000000000..afd349af9cf14 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-firmware-lfa > @@ -0,0 +1,106 @@ > +What: /sys/firmware/lfa > +Date: May 2026 > +Contact: Andre Przywara > +Description: > + The Arm Live Firmware Activation (LFA) spec describes an > + interface between platform firmware (an agent) and any user > + on the non-secure side (like the Linux kernel) to activate > + pending firmware updates at runtime. The actual firmware > + update would be provided independently (out-of-band, or > + via any existing explicit firmware update mechanisms), then, > + if supported, can be activated immediately, without rebooting > + the system. > + This directory contains one directory for each of the LFA > + capable firmware images supported by the agent, identified by > + its GUID. Within each directory, the same set of sysfs files > + provides access to the properties and actions for this > + particular firmware image. > + > +What: /sys/firmware/lfa//activate > +Date: May 2026 > +Contact: Andre Przywara > +Description: > + (WO) Write a boolean 'true' value to trigger the > + activation of that firmware component. An update must be > + pending for this to be successful. > + > +What: /sys/firmware/lfa//activation_capable > +Date: May 2026 > +Contact: Andre Przywara > +Description: > + (RO) A boolean value to show whether this firmware image is > + capable of being activated. > + > +What: /sys/firmware/lfa//auto_activate > +Date: May 2026 > +Contact: Andre Przywara > +Description: > + (RW) Write a boolean 'true' value to allow a firmware image > + to be automatically activated once a new firmware update > + becomes available ("pending"). This depends on a working > + notification scheme, for instance via an ACPI notification > + or an interrupt to notify the kernel. > + > +What: /sys/firmware/lfa//cancel > +Date: May 2026 > +Contact: Andre Przywara > +Description: > + (WO) Write a boolean 'true' value to cancel a recently > + triggered activation, if that has not finished yet. > + > +What: /sys/firmware/lfa//cpu_rendezvous > +Date: May 2026 > +Contact: Andre Przywara > +Description: > + (RO) A boolean value to show whether this image requires > + a CPU rendezvous in firmware to be activated. If true, this > + means all CPUs will enter the firmware during the activation > + process, so will not be able to execute kernel code or > + handle interrupts for a brief moment. What use does the userspace have with this 'activation_pending' and 'may_reset_cpu' ? We should drop them unless you convince otherwise. -- Regards, Sudeep