From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:45136 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234895AbhBDKku (ORCPT ); Thu, 4 Feb 2021 05:40:50 -0500 Date: Thu, 4 Feb 2021 11:40:04 +0100 From: Greg Kroah-Hartman Subject: Re: [RFC v2 1/1] PCI: Add s390 specific UID uniqueness attribute Message-ID: References: <20210204094353.63819-1-schnelle@linux.ibm.com> <20210204094353.63819-2-schnelle@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210204094353.63819-2-schnelle@linux.ibm.com> List-ID: To: Niklas Schnelle Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Peter Oberparleiter , Viktor Mihajlovski On Thu, Feb 04, 2021 at 10:43:53AM +0100, Niklas Schnelle wrote: > The global UID uniqueness attribute exposes whether the platform > guarantees that the user-defined per-device UID attribute values > (/sys/bus/pci/device//uid) are unique and can thus be used as > a global identifier for the associated PCI device. With this commit > it is exposed at /sys/bus/pci/zpci/unique_uids > > Signed-off-by: Niklas Schnelle > --- > Documentation/ABI/testing/sysfs-bus-pci | 9 +++++++++ > drivers/pci/pci-sysfs.c | 21 +++++++++++++++++++++ > 2 files changed, 30 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci > index 25c9c39770c6..812dd9d3f80d 100644 > --- a/Documentation/ABI/testing/sysfs-bus-pci > +++ b/Documentation/ABI/testing/sysfs-bus-pci > @@ -375,3 +375,12 @@ Description: > The value comes from the PCI kernel device state and can be one > of: "unknown", "error", "D0", D1", "D2", "D3hot", "D3cold". > The file is read only. > +What: /sys/bus/pci/zpci/unique_uids No blank line before this new line? And why "zpci"? > +Date: February 2021 > +Contact: Niklas Schnelle > +Description: > + This attribute exposes the global state of UID Uniqueness on an > + s390 Linux system. If this file contains '1' the per-device UID > + attribute is guaranteed to provide a unique user defined > + identifier for that PCI device. If this file contains '0' UIDs > + may collide and do not provide a unique identifier. What are they "colliding" with? And where does the UID come from, the device itself or somewhere else? thanks, greg k-h