From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL2PR02CU003.outbound.protection.outlook.com (mail-eastusazon11011045.outbound.protection.outlook.com [52.101.52.45]) (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 687231A6836; Wed, 5 Aug 2026 07:42:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.52.45 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785915766; cv=fail; b=Y/RHMwr987g5AWamr9seo2JtrtiKXUsz8vFRe3cat//HdXZwxePnM79R0O6uvek1JbEymvsuPnCjl0mZEVIuS9HapviN8sv2UyfXECAvtfXSNqMgO27nITmUy5FVLi51j04QR4F/yQcZt+PtGQ35a13qX74Mb8hCsgTlZVxhrKw= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785915766; c=relaxed/simple; bh=KP3dzmNNzusEoHhBBJbG4Bk6EiuiAIjMN9VqE6VmTDA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=GRBq9oM5zUmEH5B6Ix0gLLViQRkGLResC1sGWYqhTkpg09xROkHueY3kKNoL5KjzTsaoA8kHucN/Oh9hQpLHcmtsqx42V7n/VEGICsYyravyStaB0CzPH7F1tYCVbJSsHDDg5tz1R7RIkLwmz2ved4AHhmDKLFhCtXKVWeSXxVY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=uYdPAZ2J; arc=fail smtp.client-ip=52.101.52.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="uYdPAZ2J" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=YP+d/aqbANxYNcsOvU4DHt+gnkslFaba9pwixtaRf3TPuB3OaHZbntBzNO4kqxtvaMfG4l+9L0rjdeEh7qFBdtL5ymPErQKrmRPdifZhzmINjjsyoctqOgVhOjxGpR44ypRXj0Uzs6txgleDWMJ1aARb3jIEcLKds7/857Zh1ZMofTwUogiFVKclC1ON5Qwb0C3R4aPfYwOWw4Wgi+tF9d++243q78Rr4no44sYA8eu3qEkr2cVbJNrCSlrZvRF1coDfTfnOCTZS6Hb6mDqmQlxdlbPU1+t5kgn2fba/UFIUWtzEOyRmtBWgu7pfBWmsaoQTNEHlzzlZ+A4j4qG0hQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=hHRBwOggPoMUs34nxjUN6DWfnq5WVb4zwVPYOdxeDdk=; b=bEcRCRwITHHcjjQA+ooE7jDAj0GrXi9flf4zQJxQjFCuG3o8zlpYot+u2VxR8YBWIQhdlbehY19qsGxL9LI8YDOJYD0VVT7QksyfW0knd26AWRzzavKCeGj3WmI7GiUCZySU/7DgXck5Ww9D80ArtJkyUTP3g0IGn4HWtKAyWjmkvj+6EwqrSduPk6f7+MwD80R37cgDcAFoa3mEqJeyz0IMniukxxVnT2ToE0aAio6H994OKqka7SKbsOurqsOqWSbWeklPbgLnAjwsIwONa66K+rbvEVG6aCy2fhR4UQ8UPI+gzg7FJ/nrsplnxXAwcTAqnWIvrJ9k84q09xCVIg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=hHRBwOggPoMUs34nxjUN6DWfnq5WVb4zwVPYOdxeDdk=; b=uYdPAZ2Jstd9UCT3oT+6s3mVPa3wVxD+CAKgeEsxAN0DSIXlN2PbuXrBWalzkPw3nQw3cUlA2FuWAILX2D1HYEzur00Nhwel1hLXcVvR6LvBOrJn0/wECFGHwf+cpvT90nglarzZDtU8wGlIL2FQpXOoZ6kkqO0gieSp6dvXsgaEaygQR017g9ggX0Tp2kQMcl2ymGepZ06Yu2O3/en9UO+YW6Yp8uejsT+JLd3TPmRrSadm79m5jaMwET2MSfoQ4sVXbGXvr2DDNFAdUnWsJqCcpBM1CRXLvRpES2rzZULIK3v9LmzktaC96LXknr43Dk2MwbhhLKC3mLSWPH+utw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from MW2PR12MB2380.namprd12.prod.outlook.com (2603:10b6:907:4::32) by LV2PR12MB5966.namprd12.prod.outlook.com (2603:10b6:408:171::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.270.20; Wed, 5 Aug 2026 07:42:38 +0000 Received: from MW2PR12MB2380.namprd12.prod.outlook.com ([fe80::90d:c5c:6a5e:94a5]) by MW2PR12MB2380.namprd12.prod.outlook.com ([fe80::90d:c5c:6a5e:94a5%4]) with mapi id 15.21.0270.017; Wed, 5 Aug 2026 07:42:38 +0000 From: Richard Cheng To: dave@stgolabs.net, jic23@kernel.org, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, djbw@kernel.org Cc: iweiny@kernel.org, ming.li@zohomail.com, gourry@gourry.net, rrichter@amd.com, linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org, newtonl@nvidia.com, kristinc@nvidia.com, kaihengf@nvidia.com, kobak@nvidia.com, Richard Cheng Subject: [RFC PATCH 2/3] cxl/region: Auto-create a region for memdev attach Date: Wed, 5 Aug 2026 15:40:41 +0800 Message-ID: <20260805074042.30173-3-icheng@nvidia.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260805074042.30173-1-icheng@nvidia.com> References: <20260805074042.30173-1-icheng@nvidia.com> Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: SI2PR06CA0001.apcprd06.prod.outlook.com (2603:1096:4:186::21) To MW2PR12MB2380.namprd12.prod.outlook.com (2603:10b6:907:4::32) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MW2PR12MB2380:EE_|LV2PR12MB5966:EE_ X-MS-Office365-Filtering-Correlation-Id: 05c5d3b7-21d0-4cb1-eeea-08def2c51f14 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|1800799024|376014|7416014|366016|10067099003|56012099006|11063799006|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MW2PR12MB2380.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(23010399003)(1800799024)(376014)(7416014)(366016)(10067099003)(56012099006)(11063799006)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?TAlcnEIbpTm5+sPmzDpAJAVIg8zaJvxiU3MZjuov+dmRCbCKI46hBPVg3Xw+?= =?us-ascii?Q?8eGAhNeKy1Osuvi9CBD/rnwjscWKey0YrbXZA1h7Arb4c6jfEEGF1LiJpKL/?= =?us-ascii?Q?jySwix4zi8oBgDTtxcNUnwbs7dlXJYi+dlLrNszLy3hP8e5T0UtNhI4JDI83?= =?us-ascii?Q?YsS0g2qTMmlANw3+3K6ChexgF8FbPrOjDX5oGLAwWZGCpp18PPLft7L2Wif7?= =?us-ascii?Q?/GqXl5OZ/oREWWR9btHK1qFPjsYAhWt84MQqw/KUp4T1vsBFdFy2uGW1PNwz?= =?us-ascii?Q?YVnb8Mtty6s7EbVLdZ7v0Ptt4VIsI44YK5LJqghSuAJ8TsHKWhNPXbenPaBl?= =?us-ascii?Q?kOJwKSChSqdMivMwiAz6WivsKdlLfree9T5IPQSgKGxR3EZYgwEb6cXX7Luc?= =?us-ascii?Q?nPhaYj6TUZDZFlkTgoPL7GySNDlwBP+wzOJ6TJeYQ+uygAYae8E0rH4PCM5X?= =?us-ascii?Q?H9oOUd6DfKcIVG1rm/E/qWNU3Oh2FESaXOoRL2e3q5tT+YDvrD04MFaYyYpz?= =?us-ascii?Q?WiMY2qMNTmZinVFsMSalEvb+0RaTOD4rypvPDmXxPLso8mmjNpFNMw3ZaNgp?= =?us-ascii?Q?bgYP+VTDwKhefZ1dp067HWmPwT6kzEdRmQaz0XWjDyXxLb+TA8geh/7OPVbY?= =?us-ascii?Q?U71f7c9iyPBYSnVM5mE0BV6JHwQQIsY+wnQDj2x15tJJs8rz5Uwro+f0QqfJ?= =?us-ascii?Q?iAEIbL+NJq3eJGv922Zkhh6lpDpED4SNKYlLxTQfuk9ZKE53ZgHvDfSnSO07?= =?us-ascii?Q?kk/jUeY8R9Fz2P3LJfHYxCLDqwMtRF5NZsRJwh700P4czTbGPNnuTM6clvkd?= =?us-ascii?Q?04eglw7c1ig+Qt837Wg/sKY951BJn2gE9GizgOFU82wSuJ9GFsva1cYiMhiI?= =?us-ascii?Q?1fr8rtFZ/RC8uJiN6452+BtdRUb9WVy/R3FpIk+NcapqeirM2UgVA3c2J34S?= =?us-ascii?Q?77sYXfXraBbMjzMPgxomLK5ory391CusRLIFLDTqKAqNEhu98GeRjqG8xbbd?= =?us-ascii?Q?WJ152/DK0H6SmRvzCgYCeQhV9mIu+5rwLXIMHyHzGQUsBm4OFwlBW8qCQHyF?= =?us-ascii?Q?C43+l7Zu+MaT456yORjXkW0+TvXTPGmcBsF55amkjSJFHSo8UPvULEjECaAa?= =?us-ascii?Q?jFmCc/5cS2Ur4Z7ZGWNyA16UHWkur8wWWyfq9f8EzU4peGs9vN3wSBGc8AtD?= =?us-ascii?Q?raWCEHzcoMz0IMnq85789Nr/c/c6wJGyCdmt4UF5u7pR/+Zw2jEjmLXJ0sK8?= =?us-ascii?Q?blsetZzL22MJLF0HwwJ8pkPNxhgtDALcYp+fjuJLtPriMl6wZVJKCR8i3XqS?= =?us-ascii?Q?WmRwSpS535tKRXvcLRPsK415lFnRCkipjgmCB1+GTQg/k89GZDsXqTac8C6f?= =?us-ascii?Q?f2S/nIsh+6y0gRNFrOT4tkBSG/96fsW5ga5h0N5gyJRqmemWlISK6YPIaJdZ?= =?us-ascii?Q?cE55CCdF0cpmoxTE4I6nXu94Kr9NMjKinvTN38ylDF0aVQEbdEXH1yv2aVqU?= =?us-ascii?Q?LBn3GGdE4uea9Z6z/hR+EXA4iX7y5c2jhlwCKdfQnBnDGg8V+iPF/PdBDiJr?= =?us-ascii?Q?ZE94qpN0FLECoXz4cSh6ac5eQH1fsRXdDlaKOYJVpa+2zrK2sdK7eS7B7oxE?= =?us-ascii?Q?LXotq7NMdV0qUgDr2XQC8A/WgE21MCorv4UqqUni71HJz0xvET8Ru3D+sXDK?= =?us-ascii?Q?/+Yx7U4oeEIDbHTONEkgpVYK+Za05VA4pe6PjLLIcfZ4f2EVrdhH5GQm/FJV?= =?us-ascii?Q?djy9dGtgGw=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 05c5d3b7-21d0-4cb1-eeea-08def2c51f14 X-MS-Exchange-CrossTenant-AuthSource: MW2PR12MB2380.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Aug 2026 07:42:38.1537 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: UeoKGtuNcbQ623jvfufPRe/S0jQz6jW3kQ9xpR8DsIMvD+2RocJVh0VyF79jT/o5aVlL4+VzBid4apU3qrGUQQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV2PR12MB5966 devm_cxl_probe_mem() currently fails when FW has not committed a region, even when a Type-2 accelerator has usable CXL.mem capacity. When no mapped decoder exists, select a pristine manual DEVMEM decoder and the first compatible unlocked Type-2 RAM root decoder. Create a non-AUTO, single-target region, allocate HPA and the full volatile DPA partition, attach and commit the decoder path, then return the resulting HPA range. Use provider-managed reset for partial-commit rollback and unwind region, HPA, DPA, and partition state in reverse order on failure. Preserve the existing FW-precommitted path. This support is limited to decoder 0, IW=1, and first-compatible root selection. Signed-off-by: Richard Cheng --- drivers/cxl/core/region.c | 312 ++++++++++++++++++++++++++++++++++---- 1 file changed, 284 insertions(+), 28 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 7fcaddc61180..4ceabdfdd3b6 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -363,7 +363,8 @@ static int commit_decoder(struct cxl_decoder *cxld) return 0; } -static int cxl_region_decode_commit(struct cxl_region *cxlr) +static int cxl_region_decode_commit( + struct cxl_region *cxlr, enum cxl_region_reset_context context) { struct cxl_region_params *p = &cxlr->params; int i, rc = 0; @@ -405,7 +406,7 @@ static int cxl_region_decode_commit(struct cxl_region *cxlr) err: /* undo the targets that were successfully committed */ - cxl_region_decode_reset(cxlr, i, CXL_REGION_RESET_DEFAULT); + cxl_region_decode_reset(cxlr, i, context); return rc; } @@ -427,7 +428,8 @@ static int queue_reset(struct cxl_region *cxlr) return 0; } -static int __commit(struct cxl_region *cxlr) +static int __commit_context(struct cxl_region *cxlr, + enum cxl_region_reset_context context) { struct cxl_region_params *p = &cxlr->params; int rc; @@ -452,7 +454,7 @@ static int __commit(struct cxl_region *cxlr) if (rc) return rc; - rc = cxl_region_decode_commit(cxlr); + rc = cxl_region_decode_commit(cxlr, context); if (rc) return rc; @@ -461,6 +463,11 @@ static int __commit(struct cxl_region *cxlr) return 0; } +static int __commit(struct cxl_region *cxlr) +{ + return __commit_context(cxlr, CXL_REGION_RESET_DEFAULT); +} + static ssize_t commit_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { @@ -4177,45 +4184,271 @@ static int first_mapped_decoder(struct device *dev, const void *data) return 0; } +static int first_attach_decoder(struct device *dev, const void *data) +{ + struct cxl_port *endpoint = (struct cxl_port *)data; + struct cxl_endpoint_decoder *cxled; + struct cxl_decoder *cxld; + + if (!is_endpoint_decoder(dev)) + return 0; + + cxled = to_cxl_endpoint_decoder(dev); + cxld = &cxled->cxld; + if (cxld->id != 0 || cxled->state != CXL_DECODER_STATE_MANUAL || + cxld->target_type != CXL_DECODER_DEVMEM || cxld->region || + cxled->dpa_res || + (cxld->flags & (CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK))) + return 0; + + if (endpoint->hdm_end != -1 || cxl_num_decoders_committed(endpoint)) + return 0; + + return 1; +} + +static int first_attach_root_decoder(struct device *dev, const void *data) +{ + struct cxl_port *endpoint = (struct cxl_port *)data; + unsigned long required = CXL_DECODER_F_TYPE2 | CXL_DECODER_F_RAM | + CXL_DECODER_F_ENABLE; + struct cxl_root_decoder *cxlrd; + struct cxl_switch_decoder *cxlsd; + struct cxl_decoder *cxld; + struct cxl_dport *dport; + + if (!is_root_decoder(dev) || !device_is_registered(dev)) + return 0; + + cxlrd = to_cxl_root_decoder(dev); + cxlsd = &cxlrd->cxlsd; + cxld = &cxlsd->cxld; + if (cxlrd->dead || !cxlrd->res || + (cxld->flags & required) != required || + (cxld->flags & CXL_DECODER_F_LOCK) || + cxld->interleave_ways != 1 || cxlsd->nr_targets < 1) + return 0; + + dport = cxl_find_dport_by_dev(cxlrd_to_port(cxlrd), + endpoint->host_bridge); + return dport && cxlsd->target[0] == dport; +} + +static struct cxl_root_decoder * +find_attach_root_decoder(struct cxl_endpoint_decoder *cxled) +{ + struct cxl_port *endpoint = cxled_to_port(cxled); + struct cxl_root *root __free(put_cxl_root) = find_cxl_root(endpoint); + struct device *dev; + + if (!root) + return ERR_PTR(-ENXIO); + + /* First compatible x1 Type-2 window is strict v1 policy. */ + dev = device_find_child(&root->port.dev, endpoint, + first_attach_root_decoder); + if (!dev) + return ERR_PTR(-ENXIO); + + return to_cxl_root_decoder(dev); +} + +static void restore_attach_decoder_part(struct cxl_endpoint_decoder *cxled, + int old_part) +{ + guard(rwsem_write)(&cxl_rwsem.dpa); + cxled->part = old_part; +} + +static int select_attach_ram(struct cxl_endpoint_decoder *cxled, + int *old_part, resource_size_t *size) +{ + struct cxl_memdev *cxlmd = cxled_to_memdev(cxled); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct resource *res; + int part, rc; + + scoped_guard(rwsem_read, &cxl_rwsem.dpa) + *old_part = cxled->part; + + rc = cxl_dpa_set_part(cxled, CXL_PARTMODE_RAM); + if (rc) + return rc; + + guard(rwsem_read)(&cxl_rwsem.dpa); + part = cxled->part; + if (part < 0 || part >= cxlds->nr_partitions) + return -ENXIO; + + res = &cxlds->part[part].res; + if (res->child) + return -EBUSY; + + *size = resource_size(res); + if (!*size || !IS_ALIGNED(*size, SZ_256M)) + return -EINVAL; + + return 0; +} + +static struct cxl_region * +create_attach_region(struct cxl_endpoint_decoder *cxled, + struct cxl_root_decoder *cxlrd, resource_size_t size) +{ + struct cxl_region *cxlr; + int rc; + + guard(mutex)(&cxlrd->regions_lock); + do { + cxlr = __create_region(cxlrd, CXL_PARTMODE_RAM, + atomic_read(&cxlrd->region_id), + CXL_DECODER_DEVMEM); + } while (IS_ERR(cxlr) && PTR_ERR(cxlr) == -EBUSY); + if (IS_ERR(cxlr)) + return cxlr; + + scoped_guard(rwsem_write, &cxl_rwsem.region) { + /* Single-target IW=1 is strict v1 policy. */ + rc = set_interleave_ways(cxlr, 1); + if (!rc) + rc = set_interleave_granularity( + cxlr, CXL_DECODER_MIN_GRANULARITY); + if (!rc) + rc = alloc_hpa(cxlr, size); + } + if (rc) + goto err_unregister; + + rc = cxl_dpa_alloc(cxled, size); + if (rc) + goto err_unregister; + + rc = attach_target(cxlr, cxled, 0, TASK_UNINTERRUPTIBLE); + if (rc) + goto err_unregister; + + rc = __commit_context(cxlr, CXL_REGION_RESET_MANAGED_DETACH); + if (rc) + goto err_unregister; + + rc = device_attach(&cxlr->dev); + if (rc <= 0) { + if (!rc) + rc = -ENXIO; + goto err_unregister; + } + + get_device(&cxlr->dev); + return cxlr; + +err_unregister: + unregister_region(cxlr, CXL_REGION_RESET_MANAGED_DETACH); + return ERR_PTR(rc); +} + +static void cleanup_attach_dpa(struct cxl_endpoint_decoder *cxled, + int old_part, int setup_rc) +{ + int rc; + + rc = cxl_dpa_free(cxled); + if (rc) + dev_err(&cxled->cxld.dev, + "failed to clean up DPA after attach error %d: %d\n", + setup_rc, rc); + restore_attach_decoder_part(cxled, old_part); +} + +static int create_memdev_attach_region(struct cxl_memdev *cxlmd, + struct cxl_attach_region *attach) +{ + struct cxl_port *endpoint = cxlmd->endpoint; + struct device *decoder_dev __free(put_device) = NULL; + struct cxl_endpoint_decoder *cxled; + struct cxl_root_decoder *cxlrd; + struct cxl_region *cxlr; + struct range hpa_range; + resource_size_t size; + int old_part, rc; + + scoped_guard(rwsem_read, &cxl_rwsem.region) { + guard(rwsem_read)(&cxl_rwsem.dpa); + decoder_dev = device_find_child(&endpoint->dev, endpoint, + first_attach_decoder); + } + if (!decoder_dev) { + dev_dbg(cxlmd->cxlds->dev, + "no free manual DEVMEM decoder to auto-create a region for %s\n", + dev_name(&cxlmd->dev)); + return -ENXIO; + } + cxled = to_cxl_endpoint_decoder(decoder_dev); + + rc = select_attach_ram(cxled, &old_part, &size); + if (rc) { + restore_attach_decoder_part(cxled, old_part); + return rc; + } + + cxlrd = find_attach_root_decoder(cxled); + if (IS_ERR(cxlrd)) { + rc = PTR_ERR(cxlrd); + dev_dbg(cxlmd->cxlds->dev, + "no compatible Type-2 root decoder to auto-create a region for %s: %d\n", + dev_name(&cxlmd->dev), rc); + goto err_cleanup_dpa; + } + + cxlr = create_attach_region(cxled, cxlrd, size); + put_device(&cxlrd->cxlsd.cxld.dev); + if (IS_ERR(cxlr)) { + rc = PTR_ERR(cxlr); + goto err_cleanup_dpa; + } + + hpa_range = (struct range) { + .start = cxlr->params.res->start, + .end = cxlr->params.res->end, + }; + rc = devm_add_action_or_reset(&endpoint->dev, + endpoint_unregister_region, cxlr); + if (rc) + goto err_cleanup_dpa; + + attach->hpa_range = hpa_range; + return 0; + +err_cleanup_dpa: + cleanup_attach_dpa(cxled, old_part, rc); + return rc; +} + /* - * Runs in cxl_mem_probe context after successful endpoint probe, assumes the - * simple case of single mapped decoder per memdev. + * Attach to a firmware-precommitted region already mapped to the endpoint. + * Return 0 on success, -ENODEV when no region is present (the caller then + * auto-creates one), or a negative errno for a present-but-unusable region. */ -int cxl_memdev_attach_region(struct cxl_memdev *cxlmd) +static int find_committed_attach_region(struct cxl_memdev *cxlmd, + struct cxl_attach_region *attach) { - struct cxl_attach_region *attach = - container_of(cxlmd->attach, typeof(*attach), attach); struct cxl_port *endpoint = cxlmd->endpoint; struct cxl_endpoint_decoder *cxled; struct cxl_region *cxlr; int rc; - /* hold endpoint lock to setup autoremove of the region */ - guard(device)(&endpoint->dev); - if (!endpoint->dev.driver) - return -ENXIO; guard(rwsem_read)(&cxl_rwsem.region); guard(rwsem_read)(&cxl_rwsem.dpa); - - /* - * TODO auto-instantiate a region, for now assume this will find an - * auto-region - */ struct device *dev __free(put_device) = device_find_child(&endpoint->dev, NULL, first_mapped_decoder); - if (!dev) { - dev_dbg(cxlmd->cxlds->dev, "no region found for memdev %s\n", - dev_name(&cxlmd->dev)); - return -ENXIO; - } + if (!dev) + return -ENODEV; cxled = to_cxl_endpoint_decoder(dev); cxlr = cxled->cxld.region; if (cxlr->params.state < CXL_CONFIG_COMMIT) { - dev_dbg(cxlmd->cxlds->dev, - "region %s not committed for memdev %s\n", + dev_dbg(cxlmd->cxlds->dev, "region %s not committed for memdev %s\n", dev_name(&cxlr->dev), dev_name(&cxlmd->dev)); return -ENXIO; } @@ -4226,10 +4459,10 @@ int cxl_memdev_attach_region(struct cxl_memdev *cxlmd) return -ENXIO; } - /* Only teardown regions that pass validation, ignore the rest */ + /* Only teardown regions that pass validation. */ get_device(&cxlr->dev); - rc = devm_add_action_or_reset(&endpoint->dev, - endpoint_unregister_region, cxlr); + rc = devm_add_action_or_reset(&endpoint->dev, endpoint_unregister_region, + cxlr); if (rc) return rc; @@ -4239,6 +4472,29 @@ int cxl_memdev_attach_region(struct cxl_memdev *cxlmd) }; return 0; } + +/* + * Runs in cxl_mem_probe context after successful endpoint probe, assumes the + * simple case of single mapped decoder per memdev. + */ +int cxl_memdev_attach_region(struct cxl_memdev *cxlmd) +{ + struct cxl_attach_region *attach = + container_of(cxlmd->attach, typeof(*attach), attach); + struct cxl_port *endpoint = cxlmd->endpoint; + int rc; + + /* hold endpoint lock to setup autoremove of the region */ + guard(device)(&endpoint->dev); + if (!endpoint->dev.driver) + return -ENXIO; + + rc = find_committed_attach_region(cxlmd, attach); + if (rc != -ENODEV) + return rc; + + return create_memdev_attach_region(cxlmd, attach); +} EXPORT_SYMBOL_FOR_MODULES(cxl_memdev_attach_region, "cxl_mem"); /* -- 2.43.0