From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zmv6n21g7zF0kx for ; Thu, 22 Feb 2018 10:37:53 +1100 (AEDT) Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by bilbo.ozlabs.org (Postfix) with ESMTP id 3zmv6n1Qz1z8t6w for ; Thu, 22 Feb 2018 10:37:53 +1100 (AEDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3zmv6m3Gy0z9sW3 for ; Thu, 22 Feb 2018 10:37:52 +1100 (AEDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1LNTUjo047098 for ; Wed, 21 Feb 2018 18:37:50 -0500 Received: from e06smtp10.uk.ibm.com (e06smtp10.uk.ibm.com [195.75.94.106]) by mx0a-001b2d01.pphosted.com with ESMTP id 2g9fsgdm1y-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 21 Feb 2018 18:37:50 -0500 Received: from localhost by e06smtp10.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 21 Feb 2018 23:37:48 -0000 Subject: Re: [PATCH] ocxl: Add get_metadata IOCTL to share OCXL information to userspace From: "Alastair D'Silva" To: Frederic Barrat , Balbir Singh Cc: Arnd Bergmann , frederic.barrat@fr.ibm.com, Greg KH , "linux-kernel@vger.kernel.org" , linuxppc-dev , Andrew Donnellan Date: Thu, 22 Feb 2018 10:37:43 +1100 In-Reply-To: References: <20180221045736.7614-1-alastair@au1.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Message-Id: <1519256263.2867.8.camel@au1.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2018-02-21 at 12:25 +0100, Frederic Barrat wrote: > > Le 21/02/2018 à 07:43, Balbir Singh a écrit : > > On Wed, Feb 21, 2018 at 3:57 PM, Alastair D'Silva > .com> wrote: > > > From: Alastair D'Silva > > > > > > Some required information is not exposed to userspace currently > > > (eg. the > > > PASID), pass this information back, along with other information > > > which > > > is currently communicated via sysfs, which saves some parsing > > > effort in > > > userspace. > > > > > > Signed-off-by: Alastair D'Silva > > > > > Should we document the fields? pp_ stands for per process, but is > > not > > very clear at first look. Why do we care to return only the size, > > what > > about lpc size? > > My bad, I forgot to mention it before. There's a somewhat high-level > description which needs updating in: > Documentation/accelerators/ocxl.rst > > It doesn't go down to the level of the structure members, but at > least > all ioctl commands should have a brief description. > I'll update the docs. > lpc_size could be added. It's currently useless to the library, but > doesn't hurt. The one which was giving me troubles on a previous > version > of this patch was the lpc numa node ID, since that was experimental > code > and felt out of place considering what's been upstreamed in skiboot > and > linux so far. I'd rather add the LPC members when the rest of the LPC code goes in. At the moment, the LPC size represents the window size (as a power of 2), whereas we expect that it should represent the actual amount of LPC memory exposed. I would rather avoid changing semantics of members in released code, or burning another reserved member for the updated definition if we can avoid it. -- Alastair D'Silva Open Source Developer Linux Technology Centre, IBM Australia mob: 0423 762 819