From patchwork Fri Feb 21 01:32:05 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Li Ming X-Patchwork-Id: 13984737 Received: from sender4-pp-o94.zoho.com (sender4-pp-o94.zoho.com [136.143.188.94]) (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 48D3578F20; Fri, 21 Feb 2025 01:32:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.94 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740101565; cv=pass; b=OcQDXwA7fzwFLDYaUpNuFtjV+RN5OU00xMgHJac1SMx+gtwmqZvvzCx8o+sf0Vwq7J5KEg+J7q7/E8nkz2VTNarEAxrVUs8RN8KcVcmrRU/H9PW/W0WuepyhRzfGCFm/UFO5qgwn9qPyAYLXAe8bVPEUePgcQncNP6GCcXwawEw= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740101565; c=relaxed/simple; bh=l2ia1P25YQ3Mf4mDhF0k4Q5xMVysd29f7M4fX3GmTKQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=VFSNs41dVpvDVZ51BUn4JyxDvjHxBioq7qzeg8cdmwraerBzltB7o/cLNX8AmMsf3z8oYwTOKxz1ZqupZJIbxusdfzguce6qwWFmxE0+B7nrRkTBhoe1IbSztr1qXxPSLSbQO9eOyyaB8sz4x6DRMMllxU3A+Y7rPSubgq1PoU4= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=zohomail.com; spf=pass smtp.mailfrom=zohomail.com; dkim=pass (1024-bit key) header.d=zohomail.com header.i=ming.li@zohomail.com header.b=FB+m5EbW; arc=pass smtp.client-ip=136.143.188.94 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=zohomail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zohomail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zohomail.com header.i=ming.li@zohomail.com header.b="FB+m5EbW" ARC-Seal: i=1; a=rsa-sha256; t=1740101546; cv=none; d=zohomail.com; s=zohoarc; b=Lu43KBZtEt7AFdDQImnyCTD3tI9u93k787RdZoT6lrq3GoQZYN5BqYIG0eXgxICwGaZ3Om9SX1IJcM6aOxGdzcjdRpbxsNDGckDo814Zvvwb4qGO572whzKtTCNzEB65rh1GAPE9qlRdJs9YEq3BiC5csIyRAcr6Kq+jc2XlvGs= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1740101546; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=XbeiqXG68L38/7TIuRvqSKkNvkHaENKByIF8L8Iwwag=; b=F8/XI/oxXmoQfCNgjVsCrcOLh++tQOuZ2uiQs8HhmHQEJlA5XO4jQU02gdVtlXyUWZ+vfXp7MQ4kp5w+inTu9euoP8kxCM4tgaMzgtnvyZ6cT5gqkAk/XZX9atWfZS0v1dQIHJxi4Jgx5kK5uhAs3JfIlA8t9zGV7fIKyozIkFg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=zohomail.com; spf=pass smtp.mailfrom=ming.li@zohomail.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1740101546; s=zm2022; d=zohomail.com; i=ming.li@zohomail.com; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-Id:Message-Id:In-Reply-To:References:MIME-Version:Content-Transfer-Encoding:Feedback-ID:Reply-To; bh=XbeiqXG68L38/7TIuRvqSKkNvkHaENKByIF8L8Iwwag=; b=FB+m5EbWp8c4V+L0koNO9ccyGNA3SXW3VbajxyHTW8A1EzD6VvrNPJFZm49G0a4L ZIGOtge210cC97PMTe141zlNDiGeJAT+lCI8Px7654uhzNPuwvsSdyrY4SlKFOlLKR+ mR2/I30Nfno2X70JLHDBLMnhvAlnfmB9Ma+igDH8= Received: by mx.zohomail.com with SMTPS id 174010154362018.66000672863879; Thu, 20 Feb 2025 17:32:23 -0800 (PST) From: Li Ming To: dave@stgolabs.net, jonathan.cameron@huawei.com, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, dan.j.williams@intel.com Cc: linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, Li Ming , Jonathan Cameron Subject: [PATCH v3 7/7] cxl/region: Drop goto pattern of construct_region() Date: Fri, 21 Feb 2025 09:32:05 +0800 Message-Id: <20250221013205.126419-1-ming.li@zohomail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250221012453.126366-1-ming.li@zohomail.com> References: <20250221012453.126366-1-ming.li@zohomail.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Feedback-ID: rr0801122787e1089ae2cfd4493ccb2d0100005e49b58b3a16a64b6ce805ef390e6ff2bee79d0789ac43cbcf:zu080112271e8ff87ffc2ac7730f475cf80000f6a46113b88e0ffe05cc23c5ad4e1571e5f568cb4cbceef50c:rf0801122df3d6a5f08848c75d152a743800008096e50ab0d2c03a46f4357e7c1ba25604d2764f294324b0c49bbc4ad15a92:ZohoMail X-ZohoMailClient: External Some operations need to be protected by the cxl_region_rwsem in construct_region(). Currently, construct_region() uses down_write() and up_write() for the cxl_region_rwsem locking, so there is a goto pattern after down_write() invoked to release cxl_region_rwsem. construct region() can be optimized to remove the goto pattern. The changes are creating a new function called __construct_region() which will include all checking and operations protected by the cxl_region_rwsem, and using guard(rwsem_write) to replace down_write() and up_write() in __construct_region(). Reviewed-by: Jonathan Cameron Reviewed-by: Dave Jiang Reviewed-by: Alison Schofield Reviewed-by: Dan Williams Reviewed-by: Ira Weiny Acked-by: Davidlohr Bueso Signed-off-by: Li Ming --- v3: - Drop the renaming of __construct_region() to construct_auto_region(). (Dan) v2: - Rename __construct_region() to construct_auto_region(). (Jonathan and Dave) --- drivers/cxl/core/region.c | 81 +++++++++++++++++++++------------------ 1 file changed, 44 insertions(+), 37 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 9f082bc0f4e3..3cb91cf0e2dd 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3215,53 +3215,31 @@ static int match_region_by_range(struct device *dev, const void *data) return 0; } -/* Establish an empty region covering the given HPA range */ -static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, - struct cxl_endpoint_decoder *cxled) +static int __construct_region(struct cxl_region *cxlr, + struct cxl_root_decoder *cxlrd, + struct cxl_endpoint_decoder *cxled) { struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); - struct cxl_port *port = cxlrd_to_port(cxlrd); - struct cxl_dev_state *cxlds = cxlmd->cxlds; struct range *hpa = &cxled->cxld.hpa_range; - int rc, part = READ_ONCE(cxled->part); struct cxl_region_params *p; - struct cxl_region *cxlr; struct resource *res; + int rc; - if (part < 0) - return ERR_PTR(-EBUSY); - - do { - cxlr = __create_region(cxlrd, cxlds->part[part].mode, - atomic_read(&cxlrd->region_id)); - } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); - - if (IS_ERR(cxlr)) { - dev_err(cxlmd->dev.parent, - "%s:%s: %s failed assign region: %ld\n", - dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), - __func__, PTR_ERR(cxlr)); - return cxlr; - } - - down_write(&cxl_region_rwsem); + guard(rwsem_write)(&cxl_region_rwsem); p = &cxlr->params; if (p->state >= CXL_CONFIG_INTERLEAVE_ACTIVE) { dev_err(cxlmd->dev.parent, "%s:%s: %s autodiscovery interrupted\n", dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), __func__); - rc = -EBUSY; - goto err; + return -EBUSY; } set_bit(CXL_REGION_F_AUTO, &cxlr->flags); res = kmalloc(sizeof(*res), GFP_KERNEL); - if (!res) { - rc = -ENOMEM; - goto err; - } + if (!res) + return -ENOMEM; *res = DEFINE_RES_MEM_NAMED(hpa->start, range_len(hpa), dev_name(&cxlr->dev)); @@ -3284,7 +3262,7 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, rc = sysfs_update_group(&cxlr->dev.kobj, get_cxl_region_target_group()); if (rc) - goto err; + return rc; dev_dbg(cxlmd->dev.parent, "%s:%s: %s %s res: %pr iw: %d ig: %d\n", dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), __func__, @@ -3293,14 +3271,43 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, /* ...to match put_device() in cxl_add_to_region() */ get_device(&cxlr->dev); - up_write(&cxl_region_rwsem); - return cxlr; + return 0; +} -err: - up_write(&cxl_region_rwsem); - devm_release_action(port->uport_dev, unregister_region, cxlr); - return ERR_PTR(rc); +/* Establish an empty region covering the given HPA range */ +static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd, + struct cxl_endpoint_decoder *cxled) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_port *port = cxlrd_to_port(cxlrd); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + int rc, part = READ_ONCE(cxled->part); + struct cxl_region *cxlr; + + if (part < 0) + return ERR_PTR(-EBUSY); + + do { + cxlr = __create_region(cxlrd, cxlds->part[part].mode, + atomic_read(&cxlrd->region_id)); + } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); + + if (IS_ERR(cxlr)) { + dev_err(cxlmd->dev.parent, + "%s:%s: %s failed assign region: %ld\n", + dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), + __func__, PTR_ERR(cxlr)); + return cxlr; + } + + rc = __construct_region(cxlr, cxlrd, cxled); + if (rc) { + devm_release_action(port->uport_dev, unregister_region, cxlr); + return ERR_PTR(rc); + } + + return cxlr; } int cxl_add_to_region(struct cxl_port *root, struct cxl_endpoint_decoder *cxled)