From nobody Thu Oct 2 11:58:09 2025 Received: from mailout4.samsung.com (mailout4.samsung.com [203.254.224.34]) (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 0674F33B47C for ; Wed, 17 Sep 2025 13:42:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.254.224.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758116527; cv=none; b=Y79JA52VLtLQ9O+JEaNnzcHtvv+C0q9A82BnUf7gjHF0II+YVY7bTtepr154UyZ5u44EPOQKfcOpTSA2qYzcHHzpvY31hF3SjyJRI2iolXfce9xK59weUfLvI5RApxzVELlAtGkhmJHOq6DPQQjShEygZWp/QYOsYBXWiJEa55M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758116527; c=relaxed/simple; bh=QxgrxiYPyfgIgdcckKir9l5MmECb0kuUk85QadtiF30=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:MIME-Version: Content-Type:References; b=DYlBJQtFBfz7cTkO3xo3+qZ5MLIHZIDRfDYska+we7WtbyJTu0Cvm92Xf7t3qMW0bcwU1PBAMCZY0u8DtyxXKTrRS2eNXCo3uYk2rHI0aN1vcXlHeiH5VwBO6q5DT4gZ/Y38DpD9485/aEEdW6j+njVtIbGz7tCRUSTOK3EM65E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=samsung.com; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b=eCPREgEG; arc=none smtp.client-ip=203.254.224.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=samsung.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=samsung.com header.i=@samsung.com header.b="eCPREgEG" Received: from epcas5p1.samsung.com (unknown [182.195.41.39]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20250917134204epoutp049daea3829788c6d76ccc2366aa05f9ec~mFan-LRnI0545805458epoutp04R for ; Wed, 17 Sep 2025 13:42:04 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20250917134204epoutp049daea3829788c6d76ccc2366aa05f9ec~mFan-LRnI0545805458epoutp04R DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1758116524; bh=J/7DkBNdXlSoe7d+7pBkn1ckZK936GrNoSihihPioVU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eCPREgEG9MNIE5S6U3YSJ1PEZhVOKU7Ifv+2OosPMbBv1KSGK3WK4IHzDky/7wzyr m9VvNMMBEuBRjEiYA4k+oXVHRKxd2kgTL9HKQZFlgzTLn3KLPXqUqLdsB0dhtFrYqf OkJEGwWA4zde/TbtMx4KjwSNLTk4ax1yksT7QH9Y= Received: from epsnrtp03.localdomain (unknown [182.195.42.155]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPS id 20250917134204epcas5p2f4e766e991133c0decc2c8cea61fefab~mFanpbwR61141811418epcas5p2k; Wed, 17 Sep 2025 13:42:04 +0000 (GMT) Received: from epcas5p3.samsung.com (unknown [182.195.38.89]) by epsnrtp03.localdomain (Postfix) with ESMTP id 4cRg170hM8z3hhT4; Wed, 17 Sep 2025 13:42:03 +0000 (GMT) Received: from epsmtip2.samsung.com (unknown [182.195.34.31]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPA id 20250917134202epcas5p23f718742c74c5b519ecbbc1e04840c03~mFamD8tYo0912409124epcas5p2i; Wed, 17 Sep 2025 13:42:02 +0000 (GMT) Received: from test-PowerEdge-R740xd.samsungds.net (unknown [107.99.41.79]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20250917134200epsmtip268b889eb80e785df75d3437e164a087e~mFakFR9C60862908629epsmtip2P; Wed, 17 Sep 2025 13:42:00 +0000 (GMT) From: Neeraj Kumar To: linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org, gost.dev@samsung.com Cc: a.manzanares@samsung.com, vishak.g@samsung.com, neeraj.kernel@gmail.com, cpgs@samsung.com, Neeraj Kumar Subject: [PATCH V3 15/20] cxl: Add a routine to find cxl root decoder on cxl bus using cxl port Date: Wed, 17 Sep 2025 19:11:11 +0530 Message-Id: <20250917134116.1623730-16-s.neeraj@samsung.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250917134116.1623730-1-s.neeraj@samsung.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CMS-MailID: 20250917134202epcas5p23f718742c74c5b519ecbbc1e04840c03 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P X-CPGSPASS: Y cpgsPolicy: CPGSC10-542,Y X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250917134202epcas5p23f718742c74c5b519ecbbc1e04840c03 References: <20250917134116.1623730-1-s.neeraj@samsung.com> Add cxl_find_root_decoder_by_port() to find root decoder on cxl bus. It is used to find root decoder using cxl port. Signed-off-by: Neeraj Kumar --- drivers/cxl/core/port.c | 27 +++++++++++++++++++++++++++ drivers/cxl/cxl.h | 1 + 2 files changed, 28 insertions(+) diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 8f36ff413f5d..647d9ce32b64 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -518,6 +518,33 @@ struct cxl_switch_decoder *to_cxl_switch_decoder(struc= t device *dev) } EXPORT_SYMBOL_NS_GPL(to_cxl_switch_decoder, "CXL"); =20 +static int match_root_decoder(struct device *dev, const void *data) +{ + return is_root_decoder(dev); +} + +/** + * cxl_find_root_decoder_by_port() - find a cxl root decoder on cxl bus + * @port: any descendant port in CXL port topology + */ +struct cxl_root_decoder *cxl_find_root_decoder_by_port(struct cxl_port *po= rt) +{ + struct cxl_root *cxl_root __free(put_cxl_root) =3D find_cxl_root(port); + struct device *dev; + + if (!cxl_root) + return NULL; + + dev =3D device_find_child(&cxl_root->port.dev, NULL, match_root_decoder); + if (!dev) + return NULL; + + /* Release device ref taken via device_find_child() */ + put_device(dev); + return to_cxl_root_decoder(dev); +} +EXPORT_SYMBOL_NS_GPL(cxl_find_root_decoder_by_port, "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 3abadc3dc82e..1eb1aca7c69f 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -866,6 +866,7 @@ struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev); bool is_cxl_nvdimm(struct device *dev); int devm_cxl_add_nvdimm(struct cxl_port *parent_port, struct cxl_memdev *c= xlmd); struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port); +struct cxl_root_decoder *cxl_find_root_decoder_by_port(struct cxl_port *po= rt); =20 #ifdef CONFIG_CXL_REGION bool is_cxl_pmem_region(struct device *dev); --=20 2.34.1