From nobody Mon Feb 9 17:58:36 2026 Received: from mailout1.samsung.com (mailout1.samsung.com [203.254.224.24]) (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 E985335F8D3 for ; Fri, 9 Jan 2026 12:45:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=203.254.224.24 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767962739; cv=none; b=PRtJWk0Cs35FKq1DZbEUZ1Q2XLr9vsYJM4ti11LhZQP7xEZKzAEBBH0cnfRJ3gwfIQnfbTZt0Ma+DSSiCZMvL6bWk3pB/Gyqre71n03sOfqO91ypkqSBsakE7THjLZoN2+z5XAFKiVZT9FOaDcXOLIyW/o36oseYtMDGY1Pg4aQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767962739; c=relaxed/simple; bh=SRpErQFAGIe5nLQ85rgj4y3tPYj4P021hJOo9neEJ1s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:MIME-Version: Content-Type:References; b=UdiwZIlEbZrEngCugCVooP/OAz64QgwfwqLqf0CCIihSPQJv8vX/j9q9kuK38RhNtNklJQ4cC4jjPPmxwIvdl77PMjZgvhAJCuwpVUxVypB2cmAPqMacEC9epZp4jAovnhzrSO+kPYFc7/z6C8sy13BYSBknnWUzHpnSTZNQP5Q= 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=P/Xt9OhR; arc=none smtp.client-ip=203.254.224.24 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="P/Xt9OhR" Received: from epcas5p1.samsung.com (unknown [182.195.41.39]) by mailout1.samsung.com (KnoxPortal) with ESMTP id 20260109124534epoutp010c8762c891637bd804ca21e2de9e2a99~JEL1eam_20753707537epoutp01O for ; Fri, 9 Jan 2026 12:45:34 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20260109124534epoutp010c8762c891637bd804ca21e2de9e2a99~JEL1eam_20753707537epoutp01O DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1767962734; bh=9aNUNULuIT8Pshadtnl/hm/yM6UsRG1F6TD25Pz0Yaw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P/Xt9OhRFOTNl+IMedS+DulxNxso1VTDr+VkcZwgktlWipWstj1futSF0PIIzkqFI Mg+0SdoGux6bc9jNO0nDpU6m9TKAK/7qSTw6FqrU4YmvCzoC3szg44Szowc+MrN5k4 je99RwIQb/BftcfsOl7n+DHCTZ9KURD6cmC2xlrU= Received: from epsnrtp02.localdomain (unknown [182.195.42.154]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPS id 20260109124533epcas5p2ae2510a39153bf8ace1535a13c70629e~JEL1L4DzP0900009000epcas5p2l; Fri, 9 Jan 2026 12:45:33 +0000 (GMT) Received: from epcas5p1.samsung.com (unknown [182.195.38.87]) by epsnrtp02.localdomain (Postfix) with ESMTP id 4dnhMK1ZdWz2SSKZ; Fri, 9 Jan 2026 12:45:33 +0000 (GMT) Received: from epsmtip1.samsung.com (unknown [182.195.34.30]) by epcas5p4.samsung.com (KnoxPortal) with ESMTPA id 20260109124532epcas5p403ad41a20c916855bf3fea644ee6e5ec~JEL0EXVqa1264312643epcas5p4Z; Fri, 9 Jan 2026 12:45:32 +0000 (GMT) Received: from test-PowerEdge-R740xd.samsungds.net (unknown [107.99.41.79]) by epsmtip1.samsung.com (KnoxPortal) with ESMTPA id 20260109124531epsmtip14df269dcc7116eb68cdbbc2a66ef4805~JELy_rqgZ0972509725epsmtip1j; Fri, 9 Jan 2026 12:45:31 +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 V5 16/17] cxl/pmem_region: Create pmem region using information parsed from LSA Date: Fri, 9 Jan 2026 18:14:36 +0530 Message-Id: <20260109124437.4025893-17-s.neeraj@samsung.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260109124437.4025893-1-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: 20260109124532epcas5p403ad41a20c916855bf3fea644ee6e5ec 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: 20260109124532epcas5p403ad41a20c916855bf3fea644ee6e5ec References: <20260109124437.4025893-1-s.neeraj@samsung.com> create_pmem_region() creates CXL region based on region information parsed from the Label Storage Area (LSA). This routine requires cxl endpoint decoder and root decoder. Add cxl_find_root_decoder_by_port() and cxl_find_free_ep_decoder() to find the root decoder and a free endpoint decoder respectively. Signed-off-by: Neeraj Kumar --- drivers/cxl/core/core.h | 5 ++ drivers/cxl/core/pmem_region.c | 136 +++++++++++++++++++++++++++++++++ drivers/cxl/core/region.c | 21 +++-- drivers/cxl/cxl.h | 5 ++ 4 files changed, 159 insertions(+), 8 deletions(-) diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 5ae693269771..8421ea0ef834 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -46,6 +46,7 @@ struct cxl_region *cxl_create_region(struct cxl_root_deco= der *cxlrd, struct cxl_pmem_region_params *pmem_params, struct cxl_endpoint_decoder *cxled); struct cxl_region *to_cxl_region(struct device *dev); +bool is_free_decoder(struct device *dev); =20 #else static inline u64 cxl_dpa_to_hpa(struct cxl_region *cxlr, @@ -87,6 +88,10 @@ static inline struct cxl_region *to_cxl_region(struct de= vice *dev) { return NULL; } +static inline bool is_free_decoder(struct device *dev) +{ + return false; +} #define CXL_REGION_ATTR(x) NULL #define CXL_REGION_TYPE(x) NULL #define SET_CXL_REGION_ATTR(x) diff --git a/drivers/cxl/core/pmem_region.c b/drivers/cxl/core/pmem_region.c index 53d3d81e9676..4a8cf8322cf0 100644 --- a/drivers/cxl/core/pmem_region.c +++ b/drivers/cxl/core/pmem_region.c @@ -287,3 +287,139 @@ int devm_cxl_add_pmem_region(struct cxl_region *cxlr) cxlr->cxl_nvb =3D NULL; return rc; } + +static int match_root_decoder_by_dport(struct device *dev, const void *dat= a) +{ + const struct cxl_port *ep_port =3D data; + struct cxl_root_decoder *cxlrd; + struct cxl_port *root_port; + struct cxl_decoder *cxld; + struct cxl_dport *dport; + bool dport_matched =3D false; + + if (!is_root_decoder(dev)) + return 0; + + cxld =3D to_cxl_decoder(dev); + if (!(cxld->flags & CXL_DECODER_F_PMEM)) + return 0; + + cxlrd =3D to_cxl_root_decoder(dev); + + root_port =3D cxlrd_to_port(cxlrd); + dport =3D cxl_find_dport_by_dev(root_port, ep_port->host_bridge); + if (!dport) + return 0; + + for (int i =3D 0; i < cxlrd->cxlsd.nr_targets; i++) { + if (dport =3D=3D cxlrd->cxlsd.target[i]) { + dport_matched =3D true; + break; + } + } + + if (!dport_matched) + return 0; + + 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 + * @cxled: endpoint decoder + * + * Caller of this function must call put_device() when done as a device ref + * is taken via device_find_child() + */ +static struct cxl_root_decoder * +cxl_find_root_decoder_by_port(struct cxl_port *port, + struct cxl_endpoint_decoder *cxled) +{ + struct cxl_root *cxl_root __free(put_cxl_root) =3D find_cxl_root(port); + struct cxl_port *ep_port =3D cxled_to_port(cxled); + struct device *dev; + + if (!cxl_root) + return NULL; + + dev =3D device_find_child(&cxl_root->port.dev, ep_port, + match_root_decoder_by_dport); + if (!dev) + return NULL; + + return to_cxl_root_decoder(dev); +} + +static int match_free_ep_decoder(struct device *dev, const void *data) +{ + if (!is_endpoint_decoder(dev)) + return 0; + + return is_free_decoder(dev); +} + +/** + * cxl_find_endpoint_decoder_by_port() - find a cxl root decoder on cxl bus + * @port: any descendant port in CXL port topology + * + * Caller of this function must call put_device() when done as a device ref + * is taken via device_find_child() + */ +static struct cxl_decoder *cxl_find_free_ep_decoder(struct cxl_port *port) +{ + struct device *dev; + + dev =3D device_find_child(&port->dev, NULL, match_free_ep_decoder); + if (!dev) + return NULL; + + return to_cxl_decoder(dev); +} + +void create_pmem_region(struct nvdimm *nvdimm) +{ + struct cxl_region *cxlr; + struct cxl_memdev *cxlmd; + struct cxl_nvdimm *cxl_nvd; + struct cxl_endpoint_decoder *cxled; + struct cxl_pmem_region_params *params; + + if (!nvdimm_has_cxl_region(nvdimm)) + return; + + lockdep_assert_held(&cxl_rwsem.region); + cxl_nvd =3D nvdimm_provider_data(nvdimm); + params =3D nvdimm_get_cxl_region_param(nvdimm); + cxlmd =3D cxl_nvd->cxlmd; + + /* TODO: Region creation support only for interleave way =3D=3D 1 */ + if (!(params->nlabel =3D=3D 1)) { + dev_dbg(&cxlmd->dev, + "Region Creation is not supported with iw > 1\n"); + return; + } + + struct cxl_decoder *cxld __free(put_cxl_decoder) =3D + cxl_find_free_ep_decoder(cxlmd->endpoint); + if (!cxld) { + dev_err(&cxlmd->dev, "CXL endpoint decoder not found\n"); + return; + } + + cxled =3D to_cxl_endpoint_decoder(&cxld->dev); + + struct cxl_root_decoder *cxlrd __free(put_cxl_root_decoder) =3D + cxl_find_root_decoder_by_port(cxlmd->endpoint, cxled); + if (!cxlrd) { + dev_err(&cxlmd->dev, "CXL root decoder not found\n"); + return; + } + + cxlr =3D cxl_create_region(cxlrd, CXL_PARTMODE_PMEM, + atomic_read(&cxlrd->region_id), + params, cxled); + if (IS_ERR(cxlr)) + dev_warn(&cxlmd->dev, "Region Creation failed\n"); +} +EXPORT_SYMBOL_NS_GPL(create_pmem_region, "CXL"); diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 9a86d1c467b2..1b39f7028ca1 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -838,25 +838,22 @@ static int check_commit_order(struct device *dev, voi= d *data) return 0; } =20 -static int match_free_decoder(struct device *dev, const void *data) +bool is_free_decoder(struct device *dev) { struct cxl_port *port =3D to_cxl_port(dev->parent); struct cxl_decoder *cxld; int rc; =20 - if (!is_switch_decoder(dev)) - return 0; - cxld =3D to_cxl_decoder(dev); =20 if (cxld->id !=3D port->commit_end + 1) - return 0; + return false; =20 if (cxld->region) { dev_dbg(dev->parent, "next decoder to commit (%s) is already reserved (%s)\n", dev_name(dev), dev_name(&cxld->region->dev)); - return 0; + return false; } =20 rc =3D device_for_each_child_reverse_from(dev->parent, dev, NULL, @@ -865,9 +862,17 @@ static int match_free_decoder(struct device *dev, cons= t void *data) dev_dbg(dev->parent, "unable to allocate %s due to out of order shutdown\n", dev_name(dev)); - return 0; + return false; } - return 1; + return true; +} + +static int match_free_decoder(struct device *dev, const void *data) +{ + if (!is_switch_decoder(dev)) + return 0; + + return is_free_decoder(dev); } =20 static bool spa_maps_hpa(const struct cxl_region_params *p, diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 8c76c4a981bf..088841a3e238 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -792,6 +792,7 @@ struct cxl_root *find_cxl_root(struct cxl_port *port); DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_device(&_T->port.= dev)) DEFINE_FREE(put_cxl_port, struct cxl_port *, if (!IS_ERR_OR_NULL(_T)) put_= device(&_T->dev)) DEFINE_FREE(put_cxl_root_decoder, struct cxl_root_decoder *, if (!IS_ERR_O= R_NULL(_T)) put_device(&_T->cxlsd.cxld.dev)) +DEFINE_FREE(put_cxl_decoder, struct cxl_decoder *, if (!IS_ERR_OR_NULL(_T)= ) put_device(&_T->dev)) DEFINE_FREE(put_cxl_region, struct cxl_region *, if (!IS_ERR_OR_NULL(_T)) = put_device(&_T->dev)) =20 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); @@ -933,6 +934,7 @@ static inline int cxl_region_discovery(struct cxl_memde= v *cxlmd) #ifdef CONFIG_CXL_PMEM_REGION bool is_cxl_pmem_region(struct device *dev); struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev); +void create_pmem_region(struct nvdimm *nvdimm); #else static inline bool is_cxl_pmem_region(struct device *dev) { @@ -942,6 +944,9 @@ static inline struct cxl_pmem_region *to_cxl_pmem_regio= n(struct device *dev) { return NULL; } +static inline void create_pmem_region(struct nvdimm *nvdimm) +{ +} #endif =20 void cxl_endpoint_parse_cdat(struct cxl_port *port); --=20 2.34.1