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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 705F7C07E9D for ; Thu, 29 Sep 2022 07:46:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235137AbiI2Hqi convert rfc822-to-8bit (ORCPT ); Thu, 29 Sep 2022 03:46:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235310AbiI2HqX (ORCPT ); Thu, 29 Sep 2022 03:46:23 -0400 X-Greylist: delayed 561 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 29 Sep 2022 00:46:22 PDT Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03C13EF090; Thu, 29 Sep 2022 00:46:21 -0700 (PDT) Received: from omf07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id E3A941C60E3; Thu, 29 Sep 2022 07:36:57 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: joe@perches.com) by omf07.hostedemail.com (Postfix) with ESMTPA id E57402002C; Thu, 29 Sep 2022 07:36:44 +0000 (UTC) Message-ID: <3c02aad6d8bde70964b403a3cb8004de969becc6.camel@perches.com> Subject: Re: [PATCH v4 10/14] gunyah: sysfs: Add node to describe supported features From: Joe Perches To: Elliot Berman , Bjorn Andersson Cc: Murali Nalajala , Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Andy Gross , Dmitry Baryshkov , Jassi Brar , linux-arm-kernel@lists.infradead.org, Mark Rutland , Lorenzo Pieralisi , Sudeep Holla , Marc Zyngier , Rob Herring , Krzysztof Kozlowski , Jonathan Corbet , Will Deacon , Catalin Marinas , Arnd Bergmann , Greg Kroah-Hartman , devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 29 Sep 2022 00:36:50 -0700 In-Reply-To: <20220928195633.2348848-11-quic_eberman@quicinc.com> References: <20220928195633.2348848-1-quic_eberman@quicinc.com> <20220928195633.2348848-11-quic_eberman@quicinc.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.44.4 (3.44.4-2.fc36) MIME-Version: 1.0 X-Stat-Signature: yfqwchey9yq5eu51co5zpzk7inon4u6t X-Rspamd-Server: rspamout05 X-Rspamd-Queue-Id: E57402002C X-Session-Marker: 6A6F6540706572636865732E636F6D X-Session-ID: U2FsdGVkX1/SbFmnkC0u2VswP4hwzbj5pLQd0DpRqLM= X-HE-Tag: 1664437004-361455 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2022-09-28 at 12:56 -0700, Elliot Berman wrote: > Add a sysfs node to list the features that the Gunyah hypervisor and > Linux supports. For now, Linux support cspace (capability IDs) and > message queues, so only report those.. [] > diff --git a/drivers/virt/gunyah/sysfs.c b/drivers/virt/gunyah/sysfs.c [] > @@ -25,9 +25,24 @@ static ssize_t variant_show(struct kobject *kobj, struct kobj_attribute *attr, c > } > static struct kobj_attribute variant_attr = __ATTR_RO(variant); > > +static ssize_t features_show(struct kobject *kobj, struct kobj_attribute *attr, char *buffer) > +{ > + int len = 0; > + > + if (GH_IDENTIFY_PARTITION_CSPACE(gunyah_api.flags)) > + len += sysfs_emit_at(buffer, len, "cspace "); > + if (GH_IDENTIFY_MSGQUEUE(gunyah_api.flags)) > + len += sysfs_emit_at(buffer, len, "message-queue "); > + > + len += sysfs_emit_at(buffer, len, "\n"); > + return len; > +} It's generally nicer to avoid unnecessary output spaces. Perhaps: { int len = 0; if (GH_IDENTIFY_PARTITION_CSPACE(gunyah_api.flags)) len += sysfs_emit_at(buffer, len, "cspace"); if (GH_IDENTIFY_MSGQUEUE(gunyah_api.flags)) { if (len) len += sysfs_emit_at(buffer, len, " "); len += sysfs_emit_at(buffer, len, "message-queue"); } len += sysfs_emit_at(buffer, len, "\n"); return len; }