From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 6209A231A3B for ; Wed, 21 May 2025 18:39:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747852774; cv=none; b=bGIiQ6vR/mhsUVpekeUUfUluLwrx05XmVK3n9OTJBiFVFgGaH7Ui8ol7Cb3XqPQAvKGU16GPF8feBkiArYG3+fYe0gLj0pMGwuA6iYxDCiUJNDwmKTCYBPfw1ehLsB9seyu4rLxnh3yW9zATFNTGYxEgSXtGX1OaBmQmlXO3Iho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747852774; c=relaxed/simple; bh=nm3YFIEmy94gsONlZ/zinbKt1WEKzIi9gx/+czuvCjw=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=Uzlz3dsw8fLtodtmwx+RA38NAKSrfPPjdv6nU5Ynzvx9A65+d5HS28QA46QBtozn47UYF+ZwhCOU8Sgj6ezQSRz1CGGjQscShr39icaUM/N8VGxI+9Eh7yjChu+1lUwiJzZfXxDSHlnj5K33uwqmtb8gZ53rCWXSH5I7UIlHu4U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=H+oXS3Fk; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="H+oXS3Fk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1747852772; x=1779388772; h=message-id:date:mime-version:subject:from:to:cc: references:in-reply-to:content-transfer-encoding; bh=nm3YFIEmy94gsONlZ/zinbKt1WEKzIi9gx/+czuvCjw=; b=H+oXS3FkDjpneBjodGvS0V2BCfeU8I2/3gifZZULdIj2w/LEQOYe9Nty bBez366uakb80I3yVHkmq/OLFDdFro7owIbNdKNOpglSkIxVXoGPWfWvo t+b67/x8+jdy2Twci1MaAYp4sIYuFMZwKUyWuFzEo5r4INdHL00fd5CvC zJhzQL5evAycusqWYnUDT8e/VOE3fHXN6ILjzej/aqvLVDIxkzgsnZPfR WS4vDyPZUhMRKfHXj/m+DW/CLlUd2f1yYz83eVRX+z8MH0CoGwmTie4/v 18DIeb77InfIBoIFIqNHOMtvvYdt9fOL6ZhoRz02gNJmO23hqh1IB3NY2 A==; X-CSE-ConnectionGUID: hywIh+ZKSQa6OOGNPXIKTQ== X-CSE-MsgGUID: YBhBAxRqTISBPfot9YpYvg== X-IronPort-AV: E=McAfee;i="6700,10204,11440"; a="60487381" X-IronPort-AV: E=Sophos;i="6.15,304,1739865600"; d="scan'208";a="60487381" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2025 11:39:30 -0700 X-CSE-ConnectionGUID: zDwc9gwXTPimyvAodCOabg== X-CSE-MsgGUID: KdYJlpDeRvOHokZXrLxE5g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,304,1739865600"; d="scan'208";a="144164628" Received: from ldmartin-desk2.corp.intel.com (HELO [10.125.109.106]) ([10.125.109.106]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 May 2025 11:39:30 -0700 Message-ID: <58d89978-122f-4c79-ba04-98a1ec6e4418@intel.com> Date: Wed, 21 May 2025 11:39:29 -0700 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/9] cxl: Add helper to detect top of CXL device topology From: Dave Jiang To: linux-cxl@vger.kernel.org Cc: dave@stgolabs.net, jonathan.cameron@huawei.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, dan.j.williams@intel.com, Jonathan Cameron References: <20250521183443.3828320-1-dave.jiang@intel.com> <20250521183443.3828320-3-dave.jiang@intel.com> Content-Language: en-US In-Reply-To: <20250521183443.3828320-3-dave.jiang@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/21/25 11:34 AM, Dave Jiang wrote: > Add a helper to replace the open code detection of CXL device hierarchy > root. The helper will be used for delayed hostbridge port creation later > on. > > Reviewed-by: Jonathan Cameron I'll fix the email address. :) DJ > Signed-off-by: Dave Jiang > --- > drivers/cxl/core/port.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index 726bd4a7de27..cafb1b13cba1 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -39,6 +39,15 @@ DECLARE_RWSEM(cxl_region_rwsem); > static DEFINE_IDA(cxl_port_ida); > static DEFINE_XARRAY(cxl_root_buses); > > +/* > + * The terminal device in PCI is NULL and @platform_bus > + * for platform devices (for cxl_test) > + */ > +static bool is_cxl_hierarchy_head(struct device *dev) > +{ > + return (!dev || dev == &platform_bus); > +} > + > int cxl_num_decoders_committed(struct cxl_port *port) > { > lockdep_assert_held(&cxl_region_rwsem); > @@ -1642,11 +1651,7 @@ int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd) > struct device *uport_dev; > struct cxl_dport *dport; > > - /* > - * The terminal "grandparent" in PCI is NULL and @platform_bus > - * for platform devices > - */ > - if (!dport_dev || dport_dev == &platform_bus) > + if (is_cxl_hierarchy_head(dport_dev)) > return 0; > > uport_dev = dport_dev->parent;