From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM12-BN8-obe.outbound.protection.outlook.com (mail-bn8nam12on2087.outbound.protection.outlook.com [40.107.237.87]) (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 26CF319C54B; Fri, 4 Jul 2025 15:21:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.237.87 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751642515; cv=fail; b=sPkpUYVVhJbvuxFg0kZXWNebgaiiBmgb+Qw0kh/41rpslMrBggW6qF7vy/1dbSwXIBsmy0KnZP8s9qO0ErNTEC6YmuF7T9xpcL3Oqnb4iiV5G6D2Tk7Jmk7lAp4CvX3QxbFpNW2XCPtHLEycgZjFjnpoSD5s1vsBbYAqbeN8epA= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751642515; c=relaxed/simple; bh=c8XiOBnTdNaK/v+L0u3va6qEBaLDTKbEBQhLHUXjicg=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=Vu/zI7k8i+7F4VJLb4FlwAhn757dRwk+rVvBr56I787S8Vqp8ZWNov+z7W/ZUiSD6z5YdXCUbFHcJ6rsqczEZLlcSMhOH2iY1m7MWTgAhWumJGyGW59FDmmZSegJQJkUJfPeJHLDHbSs4ETr0ciLAASIvvqPOdThbFqnk0f3ojg= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=LBEMPx0I; arc=fail smtp.client-ip=40.107.237.87 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="LBEMPx0I" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Yu7cd1eR8v1kRpA5wKCd8TVE45Ki1/JC5tL/X8L/PufQzRquAM7UqVHp12qxHWrjK4/vyMU00lAJ0NdNJHlJX3QCE9WUiBYppR25uj72mcwWn3Jaxzx0fKC+LHfxQG08CC3bDhsWhE2IxqoVjWthjz4PulYlo37rMQA5PXfHq+e87v7xyT66zPDuinx4twHZ6aDPBm3dfJx1ACGQ6M6fTTQ6B36SokmOh88krrCjbXciLNoipU/VHw0NsedxgnhUh48TKLn7wr4P624+gnBGl3L+jM0TMmJQuxDqpqwCepYVXTKsgZi5QLfmMKn/4k7mLzYhO/CYifuqPQHm0SD8Vw== 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=TZM+v+4Ga6jgKDozGq0dQeQHk5t0f0sAUCXa7NAR1Gk=; b=Acn9LAIg4nqMJeJZHwu1xZ3JwDzArg16xXTzbAEzQgaEFFh2kJIlXfX/beLQtmjDNid3FFqm1RfopRBmXGm0SB3wwTfEz3QLV4funaxakcLkdUAZ0Xn59FXK3wH+tB07Yb8VAl/Y/E+7I3t7g6xTOnRpuFC1MhKMNGyqJv/KD66sANxLbsIuVY03Z3I8FhaxfZdhpppPu8JbeEuHX2OszwuR7HHnJolGm+zyXXJEPT7Wta2Zq7ZXodeKxthpXIK7ej+V74Xtyny59DiDyLHUBUTmQBNaXQ0oN+D38ivFZ1DWxBnZVKX7dCUAaH0BOBLmidJwnEUIaxIObidYPABnSg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=TZM+v+4Ga6jgKDozGq0dQeQHk5t0f0sAUCXa7NAR1Gk=; b=LBEMPx0IcNjGYDZVJh+jKs/9nu+PPmNz2QjD5iyQLWhFDWfK6hF/csLknbFLwl8sIkBVlIP0cuz8RGaD9mBEpx1uIyzAc12u8aAYNPGIlqUSQvPIoZUqmgItim4SauhfBlNEK4B0CgIyFUX8B6fu9ik5gon+SYuKDfohdFu+XVM= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from DM6PR12MB4202.namprd12.prod.outlook.com (2603:10b6:5:219::22) by IA0PPFFEC453979.namprd12.prod.outlook.com (2603:10b6:20f:fc04::beb) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8835.25; Fri, 4 Jul 2025 15:21:50 +0000 Received: from DM6PR12MB4202.namprd12.prod.outlook.com ([fe80::f943:600c:2558:af79]) by DM6PR12MB4202.namprd12.prod.outlook.com ([fe80::f943:600c:2558:af79%6]) with mapi id 15.20.8901.018; Fri, 4 Jul 2025 15:21:50 +0000 Message-ID: Date: Fri, 4 Jul 2025 16:21:46 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v17 13/22] cxl: Define a driver interface for DPA allocation Content-Language: en-US To: Dave Jiang , alejandro.lucero-palau@amd.com, linux-cxl@vger.kernel.org, netdev@vger.kernel.org, dan.j.williams@intel.com, edward.cree@amd.com, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Ben Cheatham , Jonathan Cameron References: <20250624141355.269056-1-alejandro.lucero-palau@amd.com> <20250624141355.269056-14-alejandro.lucero-palau@amd.com> <5b3f6c11-c51c-4f24-98c1-3d5ceadf4278@intel.com> From: Alejandro Lucero Palau In-Reply-To: <5b3f6c11-c51c-4f24-98c1-3d5ceadf4278@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: DU2PR04CA0341.eurprd04.prod.outlook.com (2603:10a6:10:2b4::30) To DM6PR12MB4202.namprd12.prod.outlook.com (2603:10b6:5:219::22) 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: DM6PR12MB4202:EE_|IA0PPFFEC453979:EE_ X-MS-Office365-Filtering-Correlation-Id: 0571f92b-9056-4716-a040-08ddbb0e7f9c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024|921020; X-Microsoft-Antispam-Message-Info: =?utf-8?B?SWROekNEM1RLUjdOU2VvWThYUEl6MStkdUE4d0tFUzZkemVBSTR2U0RPTlh4?= =?utf-8?B?Zktld05kYmc3elZ0OXJjZW54eGVxMHk4S3NNNFhoajJBREJuZFdxQjFKUXNR?= =?utf-8?B?WGNJL3lSYzIrTGF4REtwT1dWSXRMUndvWWtocUlxRU5kN0Z0NlRzdFhrejh0?= =?utf-8?B?RzkrYWlDNElxY0VHa1dMdlc2bkpFSVQwelRKTWt5RkQvQUlYTmdrQ0E0SE1N?= =?utf-8?B?Um16S1VRalpWcStPa0d5bGY4Y2FFSCtZREJoaDhlRC9SYjVGOEtxQjArWUw5?= =?utf-8?B?NGtLR3hpb0pBOEpvYXVHUXcvYUVtcEhKYi9FcTdNOUswdXVHN2VGS3ZMc2Iv?= =?utf-8?B?dCt3bkxzUm8rMFhWWWFjZGhBT0tWVW14a2VYZXc4UWZ3cmNYZTBaRzZmS3NC?= =?utf-8?B?d1dNdG81c0RobG5DelRadzN4aTdjb0VlMGRVM2F1VHUxcGY4aDRPTzc1M2pV?= =?utf-8?B?ZURuYUdITUNYNkdLd3NkbW9hNGZRMSszdzBBSC9JUlZDckNLRFNzOFljQzZl?= =?utf-8?B?ejV2UmY3c3VndTRkRkNsQmpjRHFvU1FOcU1neW9GOGZEaFZPcFd0eGRjWTRZ?= =?utf-8?B?QmpiY1BxVU12MTZ0VE02VWlFbEJtTnFFazlKZFphaVZRVHUvTmljR0JrOFda?= =?utf-8?B?amQzR2ZMelF4NzBRUEVCRmRmaGFibEQxdG9qaGhBdytXUGZpeDBldHR6TVhp?= =?utf-8?B?SnUyaW92eVhVRVgwMFRhUGM3Mzl0OU9vcnpsc290dU52c0dVcEVTNWp6bG85?= =?utf-8?B?ZmVQak5XeSt6OERBcGV2enV2U3ZXcTNsVEIwd2gvSmJDU1l5UWs0cXM0ZjUw?= =?utf-8?B?alprSDdpYXFuL2NHcytGZkp1bC9lSHU2T20reDkxUUNCZFgzeXc3U1VYWXN5?= =?utf-8?B?d1habDBpM0dNZjNNNVdURVZJSVMvaVJma2lqbHI4QzJRMVp5S3cxZ0tUMTB6?= =?utf-8?B?cC9RKzhFNitrZXA0MlAxRWpSTEhXS2VUMlB3WElBRWg4cVlSUlpwc254b3Nx?= =?utf-8?B?YUJKWHF1aVo4SllSb1VJemdLZ01FTWNUZ3gzOTZRNWxPUXkrUHlCeUdJRGMz?= =?utf-8?B?K2ZKRVBzRGdLbURNOXIxUnkyZlBNcEsvRi9LQ2VhQVRHWldjZGZtcmViTVBC?= =?utf-8?B?UTQ1UkdpNHlBRTlQZDZnbWx5a2ZWQkludWJYWHRhSUFqbndZSm5rVHY3TSs5?= =?utf-8?B?cWFGZVhKK2dZOUxpa1M1N0Zvb3YzU0xodXBqTmtvYzNSNHB2NEt5OXI5aTAx?= =?utf-8?B?Q0F6WnVITXltWUlONzNpeGRscXM5djRxSDNhVG9pZHFubUg1MFBnN2FJbmx0?= =?utf-8?B?Q2M3aGhGMDFqUFZJeGtXT2hmSTcwcmlFSEVRZmdUaVpIbkZSMlU2a25wV0lD?= =?utf-8?B?RVhwMnhSTHFjNTBtNFpUYWpuUmVCOTFva3dNSGxYTTArWVdhY291RnpWbURa?= =?utf-8?B?S2pzNlpaQTMxd1VvbUZvZHlCcDNaUkxFc2l0VzZBbzl0QXIvMmhGWjAycEox?= =?utf-8?B?bzFzdGxtUWJQT09lalRnUEtQWGltbi9qZkJJRU1rL0Q3TkdPQjB0OHBNMWls?= =?utf-8?B?bko3T0duZkVQRTRwZWU4RzJONjM4d3NNNlo0ZUJBN0NiMEdKb1pOSG4wRFRh?= =?utf-8?B?UUlEWnA3L05DMkxJVmpVVHJZUG5mYUxCY21nVFNQeXdBTWUvQ2craFZLeVFv?= =?utf-8?B?MWhkb1N5aGI0akQ5eHN3VnJxdGVSWExtV3BwdDRyWDYxSXVGeU9zZmtYRnVQ?= =?utf-8?B?R1M3U05IWnRyU01YZEs5ek80d2hlQ1BBYUNoRjdlc1Q2Wk80QU9rUGRyZWNk?= =?utf-8?B?eStnUXBLWWJIUktmNVRnL0NEUVN1dHhjRk5KWXd5NFFzUVFJM2Joc2ZzazBq?= =?utf-8?B?ak9QdkYyMmJmeU5paXlwSUcrYVRCaVNzazZhNXh0M24zWG9ZMzNoazdhZlNx?= =?utf-8?B?V2lvc1doRmpaQ04xL09qeXN2OGRSNHdGN0NKZDlpTWM5MzZMZ0o1RlRTSTRu?= =?utf-8?B?VGxvdG9rNGJRPT0=?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR12MB4202.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(366016)(1800799024)(921020);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?czFRSXYxQWRYcGtUVnNSU21DTkJ3bWIrUmNRdkY1cFpxbkFSL0MwQ2VScDBp?= =?utf-8?B?cG56TmZmYjNlSFhXalNPeHM2emxOZG41TExOcDZDZjlENzhCZ2w2NnhVdi9I?= =?utf-8?B?Ty9PV29sRC9ldFNYczJPaXVveHJRV2htd2ZyU096UkFTWEJzcUJ5aEc1TmpM?= =?utf-8?B?RjdKUEsyZ2JKejQ0ZGlxUGJSN2xkTWFqMk52cE9QWDE0YU9IN2FOdnZHOGgv?= =?utf-8?B?RHRuODNldUJoanlvVU0wZVFESGtyU0hhTzM3YkUrRk1PdUlobU5mR0phTlUv?= =?utf-8?B?Wmx5bUR2YnRoNlQrSEI0TkNFNWRRMk9EUDBHMkY1Sk00Q2pnS0IrRm5hcDJN?= =?utf-8?B?ejJEaWM3dCtJaG0wNW12THZ5WVp3OWllV2xWdHNMOEtzNlhGcU9oMEVEVnhC?= =?utf-8?B?TktNZWZaaG1kb25UYlpPclNHV2dPVWh6VjFpcTczODZCeDExd2hRcVRveU41?= =?utf-8?B?VUpXd2ZBRE1nNWpvNG90ZTAwUEJoSmxHNlR4RGwzM1BJazRaQk9LcEs4TGFF?= =?utf-8?B?TktPV3NUUVlhb3pvZDJIZEhONStoQjA0WUx1Z25XdTI3NDZlTWpIQzBuczdz?= =?utf-8?B?UlUzbFRiREcvelN0M3k5cXNEdHdOK09OMVZlcTRkazhackVBaG1meGRydG5S?= =?utf-8?B?WGo4V0R2bGJKS2ZpanRhZERzM0pldXFZdTNKMGVJRUZuYjNoQ3IxWjJScXRL?= =?utf-8?B?Z1kxOEl1ajVkVGlReXRvd3F3RFpQSVhrcGJidyt5NHJtcmhKOVNKYmJ6WUZN?= =?utf-8?B?VkdONVptRXhHenB2L2lmak1walA1NmxBUHpjdWoyTWFPR2pTRTFybHgwWUxN?= =?utf-8?B?NXhqNHJxem53bGhMaktCajlLWnhmcUp0c2l1cHdTODk4VG1GSWRYdnRzcDBT?= =?utf-8?B?Q291L1NaU0s1VkZwTDNJZ2dwV0oyU21FVTNKakZzeGova0RWN2htci9MNFlC?= =?utf-8?B?MkpQNUpGUFpCd3hZR3hYQ1dBd0lERHRXalcvV2RyM0tvK2JXL1IycGw5b1Yy?= =?utf-8?B?Zk5aNk1jcGdDd0VYUVNFbUxQbyt2d3RTV25JbTRKSGdVQmt5SWJxZ0ZraTNl?= =?utf-8?B?cjVNV3lnTnBvZ043NHVLczNvMmY1WlhrdWN4MkNYS1N0WHV3bWhrZXpPOE9W?= =?utf-8?B?MnJraU5nQXhBMlRBQThiOVloMld4VTlQUjdVNG9vVm5LRlNxa1NYK3VZMU9U?= =?utf-8?B?bVhhR0wzRDgrdEhzRU9pZ3ZMQWdlT3hWODlGMk55NmdtYTBKVGJ2SmZtcC94?= =?utf-8?B?em9ya3VIWURqblAzYkhhalBUaEZZUkJFUmgzajdkNXdiRmd5MzA0OVVMTXI5?= =?utf-8?B?VkF2a3VsUFp2Y2VvRXpESHRraENOVExYUDZRYTNPbHorSTlJT1piQUpnVFIr?= =?utf-8?B?djNhTEFQZlR0Z2haTE44bytxai9kMGluQ3FPaThXbVdmRDBhaUhJZUVycW9S?= =?utf-8?B?OXplZFp0YmdtNm5xQTlTZVowRXNlWUxXaldmMnJxb2ZZWU5HRlNlSVVseGww?= =?utf-8?B?bk1Qbk5LdGcvZkQ2RjhMZWZxVDkzeCs5VW9uVlZIMUJhZDh4OXVGNzRPbURh?= =?utf-8?B?SkxDbERwVCs5dmUrWjZ4NHNTYnIvQmFNbWRQaS9UeUNWa1FocVd0bXU0ZExN?= =?utf-8?B?aHo0RE1uTTQvU1pYTXlVLzVlNHdWLzFVa0Z1djV3d2RxZ3Z0RUlJZkNGZjFx?= =?utf-8?B?b3g4MEJnSGY5YUsyUlpXbDBsYXYzTk5HQXVZTTRHcnNxWnVvbjF1TGpaNStL?= =?utf-8?B?dURpeUM3bU1MQWtSSzk5NzNMYnNiYXN3YVhUbzJRZlFwUVBET2M0ZjlLdnM3?= =?utf-8?B?UEdoMjhhTWdtS2RRcjBLU0NZR2JmUTZXQ0RZUk5qYXllQ1Vrdk13bTRqek1w?= =?utf-8?B?MHRtNXRLbWtMclpFK0tGTUpFYTBzWDV1UTRTRGxyWjk5UDhLRlNDVHNlZ0NG?= =?utf-8?B?QnNJS1c5SVpRaDI3T1Z3TVJja0d5T3hCZ05BL2pUOEE1M2JKUm4vRVp2dmpr?= =?utf-8?B?RUNqeXdxKytkU1F6U1lzTlZRWU1EWFhxeUFPSUwvWlJqWjUxZkIzbkEwMkFR?= =?utf-8?B?TkVyV0J1ZkUwOTIxdnJETnYxOUZpS3ZvaDRiRDZCSHVqY1V2ZE1kSDFzTEIz?= =?utf-8?Q?2Qe6FC88YiXSyOqJbPtVO/RCw?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 0571f92b-9056-4716-a040-08ddbb0e7f9c X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4202.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Jul 2025 15:21:50.4338 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: smnHLYwnHvUysQ4Dljy8GCiztABQ1kRuY/MYiOYHQD7Lo8AlgX7gnBPgQ7geWYQ1JuclL1CfB2/58XoiHdY7kQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PPFFEC453979 On 6/27/25 21:46, Dave Jiang wrote: > > On 6/24/25 7:13 AM, alejandro.lucero-palau@amd.com wrote: >> From: Alejandro Lucero >> >> Region creation involves finding available DPA (device-physical-address) >> capacity to map into HPA (host-physical-address) space. >> >> In order to support CXL Type2 devices, define an API, cxl_request_dpa(), >> that tries to allocate the DPA memory the driver requires to operate.The >> memory requested should not be bigger than the max available HPA obtained >> previously with cxl_get_hpa_freespace. > cxl_get_hpa_freespace() OK > >> Based on https://lore.kernel.org/linux-cxl/168592158743.1948938.7622563891193802610.stgit@dwillia2-xfh.jf.intel.com/ >> >> Signed-off-by: Alejandro Lucero >> Reviewed-by: Ben Cheatham >> Reviewed-by: Jonathan Cameron >> --- >> drivers/cxl/core/hdm.c | 93 ++++++++++++++++++++++++++++++++++++++++++ >> drivers/cxl/cxl.h | 2 + >> include/cxl/cxl.h | 5 +++ >> 3 files changed, 100 insertions(+) >> >> diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c >> index 70cae4ebf8a4..b17381e49836 100644 >> --- a/drivers/cxl/core/hdm.c >> +++ b/drivers/cxl/core/hdm.c >> @@ -3,6 +3,7 @@ >> #include >> #include >> #include >> +#include >> >> #include "cxlmem.h" >> #include "core.h" >> @@ -546,6 +547,13 @@ resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled) >> return base; >> } >> >> +/** >> + * cxl_dpa_free - release DPA (Device Physical Address) >> + * >> + * @cxled: endpoint decoder linked to the DPA >> + * >> + * Returns 0 or error. >> + */ >> int cxl_dpa_free(struct cxl_endpoint_decoder *cxled) >> { >> struct cxl_port *port = cxled_to_port(cxled); >> @@ -572,6 +580,7 @@ int cxl_dpa_free(struct cxl_endpoint_decoder *cxled) >> devm_cxl_dpa_release(cxled); >> return 0; >> } >> +EXPORT_SYMBOL_NS_GPL(cxl_dpa_free, "CXL"); >> >> int cxl_dpa_set_part(struct cxl_endpoint_decoder *cxled, >> enum cxl_partition_mode mode) >> @@ -686,6 +695,90 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size) >> return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled); >> } >> >> +static int find_free_decoder(struct device *dev, const void *data) >> +{ >> + struct cxl_endpoint_decoder *cxled; >> + struct cxl_port *port; >> + >> + if (!is_endpoint_decoder(dev)) >> + return 0; >> + >> + cxled = to_cxl_endpoint_decoder(dev); >> + port = cxled_to_port(cxled); >> + >> + if (cxled->cxld.id != port->hdm_end + 1) >> + return 0; >> + >> + return 1; > return cxled->cxld.id == port->hdm_end + 1; OK >> +} >> + >> +static struct cxl_endpoint_decoder * >> +cxl_find_free_decoder(struct cxl_memdev *cxlmd) >> +{ >> + struct cxl_port *endpoint = cxlmd->endpoint; >> + struct device *dev; >> + >> + scoped_guard(rwsem_read, &cxl_dpa_rwsem) { > Probably ok to just use guard() here OK >> + dev = device_find_child(&endpoint->dev, NULL, >> + find_free_decoder); >> + } >> + if (dev) >> + return to_cxl_endpoint_decoder(dev); >> + >> + return NULL; >> +} >> + >> +/** >> + * cxl_request_dpa - search and reserve DPA given input constraints >> + * @cxlmd: memdev with an endpoint port with available decoders >> + * @mode: DPA operation mode (ram vs pmem) >> + * @alloc: dpa size required >> + * >> + * Returns a pointer to a cxl_endpoint_decoder struct or an error >> + * >> + * Given that a region needs to allocate from limited HPA capacity it >> + * may be the case that a device has more mappable DPA capacity than >> + * available HPA. The expectation is that @alloc is a driver known >> + * value based on the device capacity but it could not be available >> + * due to HPA constraints. >> + * >> + * Returns a pinned cxl_decoder with at least @alloc bytes of capacity >> + * reserved, or an error pointer. The caller is also expected to own the >> + * lifetime of the memdev registration associated with the endpoint to >> + * pin the decoder registered as well. >> + */ >> +struct cxl_endpoint_decoder *cxl_request_dpa(struct cxl_memdev *cxlmd, >> + enum cxl_partition_mode mode, >> + resource_size_t alloc) >> +{ >> + struct cxl_endpoint_decoder *cxled __free(put_cxled) = >> + cxl_find_free_decoder(cxlmd); >> + struct device *cxled_dev; >> + int rc; >> + >> + if (!IS_ALIGNED(alloc, SZ_256M)) >> + return ERR_PTR(-EINVAL); >> + >> + if (!cxled) { >> + rc = -ENODEV; >> + goto err; > return ERR_PTR(-ENODEV); > > cxled_dev is not set here. In fact it's never set anywhere. the put_device() later will fail. Although the __free() should take care of it right? The err path isn't necessary? As I commented with Jonathan's review, I'll fix it. >> + } >> + >> + rc = cxl_dpa_set_part(cxled, mode); >> + if (rc) >> + goto err; >> + >> + rc = cxl_dpa_alloc(cxled, alloc); >> + if (rc) >> + goto err; >> + >> + return cxled; > return no_free_ptr(cxled); Yes. Thanks! > > DJ > >> +err: >> + put_device(cxled_dev); >> + return ERR_PTR(rc); >> +} >> +EXPORT_SYMBOL_NS_GPL(cxl_request_dpa, "CXL"); >> + >> static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl) >> { >> u16 eig; >> diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h >> index 3af8821f7c15..6e724a8440f5 100644 >> --- a/drivers/cxl/cxl.h >> +++ b/drivers/cxl/cxl.h >> @@ -636,6 +636,8 @@ void put_cxl_root(struct cxl_root *cxl_root); >> DEFINE_FREE(put_cxl_root, struct cxl_root *, if (_T) put_cxl_root(_T)) >> >> DEFINE_FREE(put_cxl_port, struct cxl_port *, if (!IS_ERR_OR_NULL(_T)) put_device(&_T->dev)) >> +DEFINE_FREE(put_cxled, struct cxl_endpoint_decoder *, if (_T) put_device(&_T->cxld.dev)) >> + >> int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd); >> void cxl_bus_rescan(void); >> void cxl_bus_drain(void); >> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h >> index dd37b1d88454..a2f3e683724a 100644 >> --- a/include/cxl/cxl.h >> +++ b/include/cxl/cxl.h >> @@ -7,6 +7,7 @@ >> >> #include >> #include >> +#include >> #include >> >> /** >> @@ -247,4 +248,8 @@ struct cxl_root_decoder *cxl_get_hpa_freespace(struct cxl_memdev *cxlmd, >> unsigned long flags, >> resource_size_t *max); >> void cxl_put_root_decoder(struct cxl_root_decoder *cxlrd); >> +struct cxl_endpoint_decoder *cxl_request_dpa(struct cxl_memdev *cxlmd, >> + enum cxl_partition_mode mode, >> + resource_size_t alloc); >> +int cxl_dpa_free(struct cxl_endpoint_decoder *cxled); >> #endif /* __CXL_CXL_H__ */