From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 1FDF379DA for ; Thu, 10 Jul 2025 16:24:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752164645; cv=none; b=OY7DDo8eSmUrssmgiYqk5EVKN5jw95ZVD4SgDHZQd4dI/WdRwsmbCd5DuKDNRlnUvBJtIyUDYXx2jgIXwOZz3JYDCDyz0NjgoWQblmprCgZANZuDxxBhRZw/tFxJDi8TcuXYTVmQcaohNKcC80HJv9271K7w3ve+CIW8yBuAjGk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752164645; c=relaxed/simple; bh=zj5uiNEScsLGvfrxIy5xfLdTdtyZfSoCbqsWmaSGc5M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GkjB+VGVNuk/knVMGm/ZQsG0ezQLx1qJlCH96euOgXhGq2l2pwqRhFXONFUDZIuk7dUR3Yi3fMbAe5bWWvHBiO1HY6gVVK0HeJ41kMPz2aI6NDqhdGB6OZPFDfJ7kf4RbTGL5dGcDD1NW9A7fsbW/Cm2JDD/ZTz/p/b5E64xDoE= 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=SZnObKtr; arc=none smtp.client-ip=198.175.65.19 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="SZnObKtr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1752164642; x=1783700642; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=zj5uiNEScsLGvfrxIy5xfLdTdtyZfSoCbqsWmaSGc5M=; b=SZnObKtrXPCU3zqR+/sCX4xkkDW/NGu7ycYK6dtSUKdZ06kc4UWDvo33 K2Ztv5UPuM1V5WZUJxbwRTswjgwgfByzCDc1qynCIVRjZLixwiIAfC8wd fRTP8fGkyZJP6hFq2ZBAczjO1nxNW53vBqs1KYVdGv+wC3/TGkipN+FtQ PEsKor+elv4mXzyD1EXw5KAnsOXGo+JoAVtnC8uyeXJ/IAo+S8gLQnwtU SE1lzbW3AKDskaaoVtUOG93MNOBwncwm3xw5xVJoNqPfmd3zKG2bZXGia v5ccIRvIYnC5HMRdwjvezGvXmBZh8Y4z+ZS1CwA1yEcfxqzBKeiKX/j3R w==; X-CSE-ConnectionGUID: 7YOBLtS2RueqLrvSEOU45w== X-CSE-MsgGUID: 02M4TJaqR1yyvgGgTRAgSg== X-IronPort-AV: E=McAfee;i="6800,10657,11490"; a="54303832" X-IronPort-AV: E=Sophos;i="6.16,300,1744095600"; d="scan'208";a="54303832" Received: from orviesa002.jf.intel.com ([10.64.159.142]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2025 09:24:02 -0700 X-CSE-ConnectionGUID: cGOXdp0UT/u2JmhG2pCqkw== X-CSE-MsgGUID: CPdsE8BTTI6kmCEEFkgSHA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,300,1744095600"; d="scan'208";a="187139562" Received: from vverma7-desk1.amr.corp.intel.com (HELO [10.125.110.242]) ([10.125.110.242]) by orviesa002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2025 09:24:01 -0700 Message-ID: <29487b27-ad1a-4c6d-a1a7-26eb97e77663@intel.com> Date: Thu, 10 Jul 2025 09:23:59 -0700 Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 15/20] cxl: Add a routine to find cxl root decoder on cxl bus To: Neeraj Kumar , dan.j.williams@intel.com, dave@stgolabs.net, jonathan.cameron@huawei.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com Cc: a.manzanares@samsung.com, nifan.cxl@gmail.com, anisa.su@samsung.com, vishak.g@samsung.com, krish.reddy@samsung.com, arun.george@samsung.com, alok.rathore@samsung.com, neeraj.kernel@gmail.com, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, gost.dev@samsung.com, cpgs@samsung.com References: <20250617123944.78345-1-s.neeraj@samsung.com> <1295226194.21750165382072.JavaMail.epsvc@epcpadp2new> Content-Language: en-US From: Dave Jiang In-Reply-To: <1295226194.21750165382072.JavaMail.epsvc@epcpadp2new> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/17/25 5:39 AM, Neeraj Kumar wrote: > Add cxl_find_root_decoder to find root decoder on cxl bus. It is used to > find root decoder during region creation > > Signed-off-by: Neeraj Kumar > --- > drivers/cxl/core/port.c | 26 ++++++++++++++++++++++++++ > drivers/cxl/cxl.h | 1 + > 2 files changed, 27 insertions(+) > > diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c > index 2452f7c15b2d..94d9322b8e38 100644 > --- a/drivers/cxl/core/port.c > +++ b/drivers/cxl/core/port.c > @@ -513,6 +513,32 @@ struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev) > } > EXPORT_SYMBOL_NS_GPL(to_cxl_switch_decoder, "CXL"); > > +static int match_root_decoder(struct device *dev, void *data) > +{ > + return is_root_decoder(dev); > +} > + > +/** > + * cxl_find_root_decoder() - find a cxl root decoder on cxl bus > + * @port: any descendant port in root-cxl-port topology s/root-cxl-port/CXL port/ Please add a comment noting that the caller of this function must call put_device() when done as a device ref is taken via device_find_child(). > + */ > +struct cxl_root_decoder *cxl_find_root_decoder(struct cxl_port *port) cxl_port_find_root_decoder(). There is a cxl_find_root_decoder() already in core/region.c and could cause potential symbol clash. DJ > +{ > + struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port); > + struct device *dev; > + > + if (!cxl_root) > + return NULL; > + > + dev = device_find_child(&cxl_root->port.dev, NULL, match_root_decoder); > + > + if (!dev) > + return NULL; > + > + return to_cxl_root_decoder(dev); > +} > +EXPORT_SYMBOL_NS_GPL(cxl_find_root_decoder, "CXL"); > + > static void cxl_ep_release(struct cxl_ep *ep) > { > put_device(ep->ep); > diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h > index 30c80e04cb27..2c6a782d0941 100644 > --- a/drivers/cxl/cxl.h > +++ b/drivers/cxl/cxl.h > @@ -871,6 +871,7 @@ bool is_cxl_nvdimm_bridge(struct device *dev); > int devm_cxl_add_nvdimm(struct cxl_port *parent_port, struct cxl_memdev *cxlmd); > struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port); > void cxl_region_discovery(struct cxl_port *port); > +struct cxl_root_decoder *cxl_find_root_decoder(struct cxl_port *port); > > #ifdef CONFIG_CXL_REGION > bool is_cxl_pmem_region(struct device *dev);