From nobody Mon Feb 9 19:37:56 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 86E7B352955 for ; Fri, 23 Jan 2026 11:31:52 +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=1769167917; cv=none; b=beFJGQtVujsS7NlPRzS1I4hYe9Wov8viUvk6srn0aqsvelWcqF59LMAzeXkRdpX5f6zE558BC4TG68xmagkPQqWmoE8596fwNbfr5/rkI6itTQ2v+W4gj9wtTMDpKkevKuV/5qtNVlTCRIfiJWCDx14TZokhZgnpS6hO/sVDTFQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769167917; c=relaxed/simple; bh=EWyTHIXRjnxuz5bMEmopbPulR+K5y7vgs2pkq5uFWKU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:MIME-Version: Content-Type:References; b=R57iVqd79fXAbtaT7teAJhE8e+oaXlRzAwFetbPF2hY3FWMNXQ5YVQV2zcHogO6XWHSnX+KUwglwLTLkj0wRMw3XrELdCQM3ROhe4ToM9PMjudOv2Mu/chbPRmq/Mc3bAmAzCYbcZ/iMdR+9eQGGdgc50gecNMNw3640LzjOXLI= 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=b3/2YtWV; 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="b3/2YtWV" Received: from epcas5p1.samsung.com (unknown [182.195.41.39]) by mailout1.samsung.com (KnoxPortal) with ESMTP id 20260123113150epoutp01499b6feadbf69161f582e560392d6281~NWNdzHNwK1471314713epoutp01i for ; Fri, 23 Jan 2026 11:31:50 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20260123113150epoutp01499b6feadbf69161f582e560392d6281~NWNdzHNwK1471314713epoutp01i DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1769167911; bh=oYoasi3H98eaABmP5XK/+MqgF3n0XTF/ldFpMP/hfUw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=b3/2YtWVbesOxUIXkzF8HvWOvjN5lZvkvkW/boUOn+xVx37LXkJcGK4trYZX1X4Dr PojEGPe8qZlEhorvWPMbRZ6rXwgQMVAtIDpnKRKJzMaD9no6EvFEQeopGpdblV65mP cXM4yTpLzw87VUs2uUumOElgY9LWtoPEm29ldQro= Received: from epsnrtp01.localdomain (unknown [182.195.42.153]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPS id 20260123113150epcas5p26fb3bfbd2b99e86dcfa93b37d1da6c46~NWNdiK0PV2197121971epcas5p2f; Fri, 23 Jan 2026 11:31:50 +0000 (GMT) Received: from epcas5p4.samsung.com (unknown [182.195.38.86]) by epsnrtp01.localdomain (Postfix) with ESMTP id 4dyG3p08N7z6B9m5; Fri, 23 Jan 2026 11:31:50 +0000 (GMT) Received: from epsmtip2.samsung.com (unknown [182.195.34.31]) by epcas5p1.samsung.com (KnoxPortal) with ESMTPA id 20260123113149epcas5p1884531875d9676391e7ccc66a0f314d4~NWNcWmWly2520225202epcas5p1l; Fri, 23 Jan 2026 11:31:49 +0000 (GMT) Received: from test-PowerEdge-R740xd.samsungds.net (unknown [107.99.41.79]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20260123113148epsmtip2d45ba503047a434d45d85eb073c9865a~NWNbI8bRF2681126811epsmtip2o; Fri, 23 Jan 2026 11:31:48 +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 V6 17/18] cxl/pmem_region: Create pmem region using information parsed from LSA Date: Fri, 23 Jan 2026 17:01:11 +0530 Message-Id: <20260123113112.3488381-18-s.neeraj@samsung.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260123113112.3488381-1-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: 20260123113149epcas5p1884531875d9676391e7ccc66a0f314d4 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: 20260123113149epcas5p1884531875d9676391e7ccc66a0f314d4 References: <20260123113112.3488381-1-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 Reviewed-by: Jonathan Cameron --- drivers/cxl/core/core.h | 5 ++ drivers/cxl/core/pmem_region.c | 133 +++++++++++++++++++++++++++++++++ drivers/cxl/core/region.c | 21 ++++-- drivers/cxl/cxl.h | 5 ++ 4 files changed, 156 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..cdee2788fad8 100644 --- a/drivers/cxl/core/pmem_region.c +++ b/drivers/cxl/core/pmem_region.c @@ -287,3 +287,136 @@ 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; + int i; + + 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 (i =3D 0; i < cxlrd->cxlsd.nr_targets; i++) + if (dport =3D=3D cxlrd->cxlsd.target[i]) + break; + + if (i =3D=3D cxlrd->cxlsd.nr_targets) + 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_free_ep_decoder() - find a cxl endpoint decoder using cxl port + * @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_pmem_region_params *params; + struct cxl_endpoint_decoder *cxled; + struct cxl_nvdimm *cxl_nvd; + struct cxl_memdev *cxlmd; + struct cxl_region *cxlr; + + 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 f9b3dd6cee50..37b88641b818 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 32a8296a833a..1fc3e6260a00 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -794,6 +794,7 @@ 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); @@ -935,6 +936,7 @@ 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) { @@ -944,6 +946,9 @@ 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