From nobody Thu Oct 2 12:05:11 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 56630330D2B for ; Wed, 17 Sep 2025 13:30:55 +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=1758115857; cv=none; b=ZBp9/ApH3F0baM2J+ZSlivLc8Kdi6DMfULgyGJfE7l2R/yIgZ5g8KbImcFwAsBsPQhQE0CePHWuPyFHvk7BQBe3KEfXU1i0Wx/dnquyINnB1mytGdHajWM+GM6L9tbu1fJodov2lUwP+wejCefRQs4N9ya3dX6s188OX9KGhvtI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758115857; c=relaxed/simple; bh=QxgrxiYPyfgIgdcckKir9l5MmECb0kuUk85QadtiF30=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:MIME-Version: Content-Type:References; b=NpJtNfz42ei5Z5N1fEA1A1eicr3aoMHv/K9wOk+sC2CZkja88urYOxPz8r27ola/7ElNMyQT7030WwUCkN5CQvVTy0Qzl915RxraPU7VfAotl4aUOmLw5dCHYnCgsYhUIekCRiyTWUlXB1gV2bxkQxYVIbWEf9Mnafrvl03/6rg= 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=KDit7dYT; 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="KDit7dYT" Received: from epcas5p3.samsung.com (unknown [182.195.41.41]) by mailout4.samsung.com (KnoxPortal) with ESMTP id 20250917133053epoutp04c8d6c730a15ead5681654f9898694ae8~mFQ2-snxm2406724067epoutp04e for ; Wed, 17 Sep 2025 13:30:53 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout4.samsung.com 20250917133053epoutp04c8d6c730a15ead5681654f9898694ae8~mFQ2-snxm2406724067epoutp04e DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1758115853; bh=J/7DkBNdXlSoe7d+7pBkn1ckZK936GrNoSihihPioVU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KDit7dYTbE0dQXYj5H2NP5NA0O1+biffePsN1Eyxm3QfGXTL4n3Nwuo25Y7aMQ0YA mhB3XvPEA7qDGSPsw0H7VcH6EN4u8fqFz+o4oc8Q1b2S3Aa0aCBxDqVWCVb4XohUEB SJw0doADesW5lCH2g9Fc9gOxmDYomjYRA440IWyY= Received: from epsnrtp03.localdomain (unknown [182.195.42.155]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPS id 20250917133053epcas5p2a2e7ee94016c20160f8511f1d1f1c1f4~mFQ2s2pw80979409794epcas5p2l; Wed, 17 Sep 2025 13:30:53 +0000 (GMT) Received: from epcas5p1.samsung.com (unknown [182.195.38.90]) by epsnrtp03.localdomain (Postfix) with ESMTP id 4cRfmC6rNqz3hhT8; Wed, 17 Sep 2025 13:30:51 +0000 (GMT) Received: from epsmtip1.samsung.com (unknown [182.195.34.30]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPA id 20250917133051epcas5p230bd96e4bad5f8608505d7a56a84f1c3~mFQ1TI4_U1088010880epcas5p2f; Wed, 17 Sep 2025 13:30:51 +0000 (GMT) Received: from test-PowerEdge-R740xd.samsungds.net (unknown [107.99.41.79]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20250917133050epsmtip15e3b7e6d6345f1152ed8470fa5f77247~mFQ0P_e6x0457804578epsmtip1Z; Wed, 17 Sep 2025 13:30:50 +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, 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 18:59:35 +0530 Message-Id: <20250917132940.1566437-16-s.neeraj@samsung.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250917132940.1566437-1-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: 20250917133051epcas5p230bd96e4bad5f8608505d7a56a84f1c3 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 105P cpgsPolicy: CPGSC10-542,Y X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250917133051epcas5p230bd96e4bad5f8608505d7a56a84f1c3 References: <20250917132940.1566437-1-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