From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL0PR03CU003.outbound.protection.outlook.com (mail-eastusazon11012022.outbound.protection.outlook.com [52.101.53.22]) (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 64D3B33F582; Fri, 26 Jun 2026 03:53:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.53.22 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782445993; cv=fail; b=UO4a56RJ3EOxuLeyAAO5TB35CUQDVgwfJzOpsEWWl8wcL3liZaD53wXg6K+C4bi1yTzY9YmJ31qewDcncTHXhBvA41sLOyESwRfjW4rr03w6LmpFr9GV90F4wPnDlLPG7MbwZJTyxwfOvSC5zGDuvfZBn7+AWTu007ePJYgdXxM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782445993; c=relaxed/simple; bh=vuGKmZTIc34c4nsL0U7yNGEKOOkYGM/p9p8GTUvKmh4=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=ewdecgGDJEgZRo95yyrohZ0rcPxBH9EJHOEZ738mzjGD6xKCFs/Yia88wPO3lRuOkgaexJSewNwiRdnADPv1MWSl8CFLshwnBD8feU5gpe+rMI3aZH8Cs5pnz4iFtfG9X1+elrGfQJ+ZAxpD/r540woKg8a8e34sT2MT6a3OMyg= 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=bDt2wv0T; arc=fail smtp.client-ip=52.101.53.22 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="bDt2wv0T" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=S7Q1joGlwRKCFXGcPVH4XfqGZGiDRpTnOx7t7aWwP5KDt4+KylOgeMBjrey5AOVIR8WXV6whh3IgQ6IgjBAmd+JWtR6AP5UvxlyPJ5wmV44599gvv8kRZ1uRTDD8QFV5SSL7mfAXQtkEHfLc/vKGE81u6IqlNgrugQvKa29GJvaGoJHepNvtkGN56gXdvsjr93TUNE+82NikTthjruf3TWZcD/aTKTj/94/G66PJb9tNcdZ0vvZWzqZr1h1M7Fx0Aga/Rr95UIvO4POPBL7UGU3R3ETILDNXDjfQeyn+pPOURjpuMLdWN0hVCZWOUcPltdGiPzSuXiYKHQuTwZr3sw== 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=dHyq107M5kLkM0Ofsel7KJjk8GndZT+AresbQWvPeDo=; b=amGbRWZMkOkLFT0yF4NyylR5tcb6UtAg7qSxML0F5kENln7DwtzO8iLEsMoynpq7jHJYj7kmxJlLJ8L+8aUIXabgGGkdtQ8y1IB4ZMHmGwRZI6hhbgbtmZAA99gsLy85Pg8ebJO1bzcGzgPLxH4fpxseT8aCyt/FuFr+O3AULlGT9+BpEPtDLA7XQaYse/K5IZ5hf0m6BcW7/AFUsuz5AvN7fGxlmXoVAZDpuiQx5vUQXHoNOYhQ9/SptFMa662NcK1VAWNrwVtk1QeB8Lj3aO1kKC9t88YcBlV5C4FKtBvofkInkuAZ27FNiYVV9xDXc7o8QTd3K98v+mNpUJbEHQ== 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=dHyq107M5kLkM0Ofsel7KJjk8GndZT+AresbQWvPeDo=; b=bDt2wv0TPgOnWl+kLTQcUdk62CR66eOLcuUd9OXjFEeFJ4LGvCqiSeMHQwffyRyvUbxTsHG/21s5N7QcMKOgcj32eU0z9knKjM2VjK+P6mB+FzFUPR6GACJoZzp4ETteF3qMsqTfrd0n7PupO4I+k2mwBGpToJHtlxGguqMqVjD7ahZ6osTmUqRODcG15x7HBCRv68naCr0fGxd3W+6LLegKPGeST/dualfQ/NkXIOxxvZzND7F8Du4zLPAd3l0Pv/lxKAro1a2RAmFzs7HE46V15j9y22lrT3NNMwgly52yZoT5BHGoy6AMR50lNaxW7BaGHcbp+BLjS9+QC4SG6w== 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 CH3PR12MB8354.namprd12.prod.outlook.com (2603:10b6:610:12f::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.159.17; Fri, 26 Jun 2026 03:53:06 +0000 Received: from MW2PR12MB2380.namprd12.prod.outlook.com ([fe80::90d:c5c:6a5e:94a5]) by MW2PR12MB2380.namprd12.prod.outlook.com ([fe80::90d:c5c:6a5e:94a5%6]) with mapi id 15.21.0159.015; Fri, 26 Jun 2026 03:53:06 +0000 Date: Fri, 26 Jun 2026 11:52:37 +0800 From: Richard Cheng To: alejandro.lucero-palau@amd.com Cc: linux-cxl@vger.kernel.org, netdev@vger.kernel.org, dan.j.williams@kernel.org, edward.cree@amd.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, dave.jiang@intel.com, Alejandro Lucero , Edward Cree Subject: Re: [PATCH v29 4/5] sfc: obtain and map cxl range using devm_cxl_probe_mem Message-ID: References: <20260622124010.2192888-1-alejandro.lucero-palau@amd.com> <20260622124010.2192888-5-alejandro.lucero-palau@amd.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260622124010.2192888-5-alejandro.lucero-palau@amd.com> X-ClientProxiedBy: SG2P153CA0019.APCP153.PROD.OUTLOOK.COM (2603:1096:4:c7::6) To BL0PR12MB2370.namprd12.prod.outlook.com (2603:10b6:207:47::27) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MW2PR12MB2380:EE_|CH3PR12MB8354:EE_ X-MS-Office365-Filtering-Correlation-Id: b2d8d939-abc4-4a53-e5d7-08ded3366304 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|1800799024|376014|7416014|366016|6133799003|18002099003|22082099003|56012099006|11063799006|4143699003; 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)(6133799003)(18002099003)(22082099003)(56012099006)(11063799006)(4143699003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?TG8z6F5tKOiDdoD6H5frbZonHdRaxA28KlWgtLszGd9OB7v2vjUp0bLaAdjE?= =?us-ascii?Q?+Aha2KXWyMVVhTkoYznzEJsiEZ4RNeDDZyZ1ufSqZP7Re7tPNW5obIZQivxj?= =?us-ascii?Q?Jpd3dL7Qz9e+Bw0njLAbU7N8RswDOuWGYUiQvr7kdYyD0KWlqRAEpFPehqAP?= =?us-ascii?Q?SdMfHC4gKv/aYBFi1tx5v3EZXW7LzyAT4p2jU6T9L8c6D+sU4SS2P8zGJ0F2?= =?us-ascii?Q?DaJ9BTFNhM4+Z3DiytlLBDeVdyjMCuha90ZqgUnf0CgH7RzMLdhYW0i2dAbC?= =?us-ascii?Q?b5KW7opIv0r6TWgu+YPrPXcFxLgtflH3dN4SkPqi6IlH2Fp28vkKR2yvXAtz?= =?us-ascii?Q?2T5huK288FieBn4Ok49LMjxgWF10iBjkRa6X7+yq40B3AN0s09mbeEzhiuRz?= =?us-ascii?Q?cYq+BPBaHW7fddtU0vnshiNUFYCtlvLXqe62LMthqqZgY2xcxaDzmqu9byEP?= =?us-ascii?Q?IAk/yHujCQjMxD7ZVwoWcqRGhwRE9kMipciGR/ZutytOm1RYK65HUX18Rsw0?= =?us-ascii?Q?p20VGOxi3JTQsBJr9l+wKWAGiT9q7E4RAhedJVsoceBTFtwA4LSpcLG4e5QM?= =?us-ascii?Q?yxh66dpXdYHZHyC65MJBU78f7q+4IUHSt+nUsja4+pXDHmBt1AXJGrCO2XTW?= =?us-ascii?Q?hhDseyRAlwoPdGwH1Q6J7WBIroFnm2maGmggHCuo7wNSW6f/ETQTCQn7dY7r?= =?us-ascii?Q?pLPj9fvSCyH/+w3/O2CzVD5EOC9grX+DlXEKJRL1CqasYQZP3Ov1HU51lB5W?= =?us-ascii?Q?wpf7a5P4Vh9VZKdD3XBuF+Bd4zeoN9PH8xbHPIhocpAOE6n1Doej4SCit6Fq?= =?us-ascii?Q?0ykdfCPoFz21dfgM0nw0km3YrnxbytmCiVKavKtFa+mksO0IikIzlLO6ppCD?= =?us-ascii?Q?xFY3Mw0Ghpt0+DD6XP3ekFLux25puFijqtjk9TPvrzvIBgnMK4hAJgzeR6Za?= =?us-ascii?Q?0KNTsAzj0LwMdF2OBfOsOUR/kOW//3A1BN/KYILnD8lXCOtcsI67tSoYbQlg?= =?us-ascii?Q?oxhau3iEKznchSZnDUI+M68rmOsSWhipMOE0YIWI17sw/9eV6izt+MH+4SQd?= =?us-ascii?Q?5wMnBx69+7jQxnbIYbqwNdslf4GtxkL5sGj55Dht78Wq3nUJ/WbL6aMwgPhN?= =?us-ascii?Q?sDpf2jQbtA7vsObWrHbt2ZScDFuUeHXFXmDq8mIkFmCmUJl2j+++MZssENuH?= =?us-ascii?Q?Hmsrd63tzc7k25C8VXlvKA9eR8FgoNWZsQ4Y3OMuHN/eohXjMu8hZtW7E7/x?= =?us-ascii?Q?WFXM6JPKlp/LsvfiUvX5vYJZUDzXzYgvH9BsyCudacAFC45Yoy6CBL5ZKDPA?= =?us-ascii?Q?+2UlgLSBTQYebpX/rANtdLVvvduGsGuMALTDs9cAZP2E/+jql1fZg1xzla2N?= =?us-ascii?Q?hG2UuKSgqGZiQYSCYdRJsV8YjubYpJlipLwLzB/44feQ57WY140nE0LGR3bP?= =?us-ascii?Q?pHnLKkVGNGiGg6Ww0o+u3EKCx4yKBU2rsj8O/gvU8kEpkvmNi1NghueXTlpn?= =?us-ascii?Q?/t/Gai7G7bLfNQ2hI4qQR4ToYo2WWE57JsiTVE5JIODPPFb1xFpXy5RcvTyW?= =?us-ascii?Q?0c5PlOQSCJLTbgO5VD4gA6CN6VMI6TPmFWKFvPxVapKGJqHAWgX2lR+ooZG+?= =?us-ascii?Q?n9xAs5SYHdvmAn4LJEyJNqF+X+WLdY9Mn//OSOlKKSbPLhwN7OhBYouOE+i7?= =?us-ascii?Q?GqMEX+cxParAFnHqseO8ox56KEhtnwGGrOw7mD/k8sD+RJq01QRWz6vjHTwy?= =?us-ascii?Q?JYEW5pjJNA=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: b2d8d939-abc4-4a53-e5d7-08ded3366304 X-MS-Exchange-CrossTenant-AuthSource: BL0PR12MB2370.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Jun 2026 03:53:05.9178 (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: H0JtTvroNgQHN4v0aHRGVN4JfVZbLIz5HydQvy+TE3ak/FrqvV/UxD5GCWVYo9rsxL7UENOUPWzog3PX5YY3hA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR12MB8354 On Mon, Jun 22, 2026 at 01:40:09PM +0800, alejandro.lucero-palau@amd.com wrote: > From: Alejandro Lucero > > Use core API for safely obtain the CXL range linked to an HDM committed > by the BIOS. Map such a range for being used as the ctpio buffer. > > A potential user space action through sysfs unbinding or core cxl > modules remove will trigger sfc driver device detachment, with that case > not racing with this mapping as this is done during driver probe and > therefore protected with device lock against those user space actions. > > Signed-off-by: Alejandro Lucero > Reviewed-by: Dave Jiang > Acked-by: Edward Cree > --- > drivers/net/ethernet/sfc/efx.c | 2 ++ > drivers/net/ethernet/sfc/efx_cxl.c | 23 +++++++++++++++++++++++ > drivers/net/ethernet/sfc/efx_cxl.h | 3 +++ > 3 files changed, 28 insertions(+) > > diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c > index 61cbb6cfc360..3806cd3dd7f4 100644 > --- a/drivers/net/ethernet/sfc/efx.c > +++ b/drivers/net/ethernet/sfc/efx.c > @@ -984,6 +984,7 @@ static void efx_pci_remove(struct pci_dev *pci_dev) > efx_fini_io(efx); > > probe_data = container_of(efx, struct efx_probe_data, efx); > + efx_cxl_exit(probe_data); > > pci_dbg(efx->pci_dev, "shutdown successful\n"); > > @@ -1242,6 +1243,7 @@ static int efx_pci_probe(struct pci_dev *pci_dev, > return 0; > > fail3: > + efx_cxl_exit(probe_data); > efx_fini_io(efx); > fail2: > efx_fini_struct(efx); > diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c > index 18b535b3ea40..3e7c950f83e9 100644 > --- a/drivers/net/ethernet/sfc/efx_cxl.c > +++ b/drivers/net/ethernet/sfc/efx_cxl.c > @@ -18,6 +18,7 @@ int efx_cxl_init(struct efx_probe_data *probe_data) > { > struct efx_nic *efx = &probe_data->efx; > struct pci_dev *pci_dev = efx->pci_dev; > + struct range cxl_pio_range; > struct efx_cxl *cxl; > u16 dvsec; > int rc; > @@ -73,9 +74,31 @@ int efx_cxl_init(struct efx_probe_data *probe_data) > return -ENODEV; > } > > + cxl->cxlmd = devm_cxl_probe_mem(&cxl->cxlds, &cxl_pio_range); > + if (IS_ERR(cxl->cxlmd)) { > + pci_err(pci_dev, "CXL accel memdev creation failed\n"); > + return PTR_ERR(cxl->cxlmd); > + } > + > + cxl->ctpio_cxl = ioremap_wc(cxl_pio_range.start, > + range_len(&cxl_pio_range)); Hi Alejandro, A small question here, Is it possible that the FW would commit a region bigger than the range ? The committed CXL region length is never validated against the PIO window size. The legacy patch sizes wc_mem_map_size to cover the VI-strided PIO offset, but here we ioremap whatever the BIOS comitted and assume it's EFX_CTPIO_BUFFER_SIZE. Maybe adding """ if (range_len(&cxl_pio_range) < EFX_CTPIO_BUFFER_SIZE) return -EINVAL; """ Would be worthy ? Let me know what you think. Best regards, Richard Cheng > + if (!cxl->ctpio_cxl) { > + pci_err(pci_dev, "CXL ioremap region (%pra) failed\n", > + &cxl_pio_range); > + return -ENOMEM; > + } > + > probe_data->cxl = cxl; > > return 0; > } > > +void efx_cxl_exit(struct efx_probe_data *probe_data) > +{ > + if (!probe_data->cxl) > + return; > + > + iounmap(probe_data->cxl->ctpio_cxl); > +} > + > MODULE_IMPORT_NS("CXL"); > diff --git a/drivers/net/ethernet/sfc/efx_cxl.h b/drivers/net/ethernet/sfc/efx_cxl.h > index 04e46278464d..3e2705cb063f 100644 > --- a/drivers/net/ethernet/sfc/efx_cxl.h > +++ b/drivers/net/ethernet/sfc/efx_cxl.h > @@ -20,10 +20,13 @@ struct efx_probe_data; > struct efx_cxl { > struct cxl_dev_state cxlds; > struct cxl_memdev *cxlmd; > + void __iomem *ctpio_cxl; > }; > > int efx_cxl_init(struct efx_probe_data *probe_data); > +void efx_cxl_exit(struct efx_probe_data *probe_data); > #else > static inline int efx_cxl_init(struct efx_probe_data *probe_data) { return 0; } > +static inline void efx_cxl_exit(struct efx_probe_data *probe_data) {} > #endif > #endif > -- > 2.34.1 > >