From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 74C6C3128B2; Thu, 18 Jun 2026 20:21:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=198.175.65.17 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781814099; cv=fail; b=spvp4iuLY26D1vlrwcgqKiVPebrWf/xubkEKE2E5Irnl371OEScw0G/VfnkRW9LGKOuzgDiacvviiss4CrnNIzkZS1jd6AaLCDpK1p7vdClM7pmDqbKAUQNS47hzHPNdfe2ubrfOb9WqaoO1cQO4aTlAb6yFE/rOyCFw1EPps1g= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781814099; c=relaxed/simple; bh=v8zQ55+K7GLNGcPzxSuRLijbOhedIHZfYw2Wue9s3UM=; h=Date:From:To:CC:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=rnusaOvLEX4k1tSGkkQqX/8Sh1olNRvIcQsPVl2buDrJJyN5UJcLiL2HT65ATQXGY/XKSy6HV5yYlEvTlvWfO8cj4Wc50HbeDIcE4oo2FtfmPJJX858SJrVnf0iw0Os3w7GDu7LFavARAYtLcHW151k4pDd2o2QO8neFRiKIZko= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=lOP4957T; arc=fail smtp.client-ip=198.175.65.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="lOP4957T" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1781814098; x=1813350098; h=date:from:to:cc:subject:message-id:references: in-reply-to:mime-version; bh=v8zQ55+K7GLNGcPzxSuRLijbOhedIHZfYw2Wue9s3UM=; b=lOP4957ToeM+8Ax2LDu75VRbEC07rjO/MZzRYOh2zqKt3PgO1PZkRJOd FGvOEb5W7mWpb4KwSi6q9V3kMzIbg//GltmFaw1PJKJ4RT9OGnkTBQNE4 ADmlJKTbffoN7Vye0cCJ4eF8IJ91dWB3CJaE9P9eTsaETftHFePuWWJdn lW1Xa3kSDKaq8+WyWg+MDGm5ck76yVsiNirWc5TfbhW1DrvCKM9CZgOYU tj4+u4CIxyuXeDCXDSo/jINXGTjSv7xS0iUz8ZpfjlMlSb8E+NOaMYkzg giTxMtrIykRxjo0SVRX2MYW2xlCZxqC8ARLS4nyTeaeNQYVqV5NRjsPxl A==; X-CSE-ConnectionGUID: 8MMSdnbASvCwW6LKOE9wUg== X-CSE-MsgGUID: 4MK+wweNQqCcQHnfe6cSZQ== X-IronPort-AV: E=McAfee;i="6800,10657,11821"; a="82667965" X-IronPort-AV: E=Sophos;i="6.24,212,1774335600"; d="scan'208";a="82667965" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2026 13:21:38 -0700 X-CSE-ConnectionGUID: yQmzFDrMTrSE5mym5yWHgQ== X-CSE-MsgGUID: NBtxzsoiRAenUmmXmq78uw== X-ExtLoop1: 1 Received: from fmsmsx902.amr.corp.intel.com ([10.18.126.91]) by fmviesa003.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Jun 2026 13:21:37 -0700 Received: from FMSMSX901.amr.corp.intel.com (10.18.126.90) by fmsmsx902.amr.corp.intel.com (10.18.126.91) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Thu, 18 Jun 2026 13:21:37 -0700 Received: from fmsedg901.ED.cps.intel.com (10.1.192.143) by FMSMSX901.amr.corp.intel.com (10.18.126.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37 via Frontend Transport; Thu, 18 Jun 2026 13:21:37 -0700 Received: from CO1PR03CU002.outbound.protection.outlook.com (52.101.46.0) by edgegateway.intel.com (192.55.55.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Thu, 18 Jun 2026 13:21:37 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=VeXfGOgVjaF1gKIWe2BvmbhNvaG3+E8GOi8MPZfYnQVpb2Rb6rlNpFhkNXH7wuxZePSyCy+8uLuUitYB/UIQ4kHbRYDLhVdgBShADLv/eRGPtBnZqEgeDsNY2PAfpq0G38xiQRLaNPPegXnVQZglBzpKUsh0SXyN8DeyGPBEWjyMKImMqWGjkiizwUjv8RBlJv2A7QUzld6fOSsMj/AeyXPhOb9JEZmjJkOOIlW5kCJVFqDixi1P5ziEn0jbN6aHd50UvkHloUmsglg4aoR9uK6kDhuCuzeNkXsYS40CDdv/qIp4Zx0LI5XYMbxoSjEtu9SMBq5WWv7DN6rq8g1ugg== 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=bHinaXYT9z3SdP1OSxam+XFxmAZd1P6E+NKau5eve44=; b=qRS8inK9zLxHPK8Fw1UAcL2fHumceC+Gg7Vg06fd+i+CClnOnz7+sXqgOwC9Um5Bi1tNmr8bpd6/dcd5nz+RkBdqwWCk9uBNHhX8cSQsD315uqAhd3R9sW8GZy+Ns0hYx6Mg2VItMU2/IEvXx6n4kD9vD6fbi6oChyFVQa1y9GXPosXWgbOYJ7LlsliQH2Wk8PC/JBjaeAa2rBJG4btSIuM/N//4m57laCa6iZQP6H+IoQp5AE+25pLgsVLGYfv+H35fx2+KCI07TycyW/i0VxprQu95t85f2KfPH2ivkzKvSdpK7Rbjzfn9FyEWJYcwU2/7axlC8e8K7GN2m9DtDg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from DS4PPF0BAC23327.namprd11.prod.outlook.com (2603:10b6:f:fc02::9) by SJ5PPF5B09F0799.namprd11.prod.outlook.com (2603:10b6:a0f:fc02::82c) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.139.11; Thu, 18 Jun 2026 20:21:30 +0000 Received: from DS4PPF0BAC23327.namprd11.prod.outlook.com ([fe80::a195:49d4:38c5:3891]) by DS4PPF0BAC23327.namprd11.prod.outlook.com ([fe80::a195:49d4:38c5:3891%4]) with mapi id 15.21.0139.009; Thu, 18 Jun 2026 20:21:30 +0000 Date: Thu, 18 Jun 2026 13:21:25 -0700 From: Alison Schofield To: Anisa Su CC: , , , Dan Williams , Jonathan Cameron , Davidlohr Bueso , Dave Jiang , Vishal Verma , Ira Weiny , John Groves , Gregory Price , Ira Weiny Subject: Re: [PATCH v10 07/31] cxl/region: Add DC DAX region support Message-ID: References: <9f0e0b3deeb1825ad113d7aebe7056dcf2bbc5f9.1779528761.git.anisa.su@samsung.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <9f0e0b3deeb1825ad113d7aebe7056dcf2bbc5f9.1779528761.git.anisa.su@samsung.com> X-ClientProxiedBy: BY1P220CA0004.NAMP220.PROD.OUTLOOK.COM (2603:10b6:a03:59d::15) To DS4PPF0BAC23327.namprd11.prod.outlook.com (2603:10b6:f:fc02::9) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS4PPF0BAC23327:EE_|SJ5PPF5B09F0799:EE_ X-MS-Office365-Filtering-Correlation-Id: 31dbdf1d-7fa3-48d5-bba3-08decd772e6d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|7416014|376014|1800799024|366016|56012099006|11063799006|5023799004|18002099003|22082099003|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:DS4PPF0BAC23327.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(23010399003)(7416014)(376014)(1800799024)(366016)(56012099006)(11063799006)(5023799004)(18002099003)(22082099003)(4143699003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?Jn+ISjDzfZF5nHT5jAFqL2pFOqyiOFp4bW8vh9RjQUsJQxa2eFMlW1jsXjWw?= =?us-ascii?Q?ISccJZGl3WNCVrLBgcv08LteLbVd1k2nUpZ8U705HJrTWIWz62ctsO8yUezb?= =?us-ascii?Q?u1D4IUm/7HGYQ6HkgoRncTVbDSmppXq50KuN7l/VBT9lmFgT/Dg+rvfWjxmn?= =?us-ascii?Q?f50JWmljVRhjzIrEqM4Mz3imYrEZDxZo1WQGfkok/qnrqizOyTGX/R2N/KSA?= =?us-ascii?Q?xqC2+FhzxGUcSvCK/WCb+Ncg5LUkcsh5fe2tCuaicQ8mFCluUev2eIRV2qcz?= =?us-ascii?Q?LliE6loQIUq1pPYhgg07yat7I/I4zzdxhLkqo/ghCIiTPN+YLorrssXegQPV?= =?us-ascii?Q?EDk8fku06LOZ74JFp3DcSNY0Rfk3FzBFnmMgfzH7jCMrVY8IywXbJ0QCQFoV?= =?us-ascii?Q?xeuYUQp402IZWzCUen9V/gLm5+djfMskbE4JIO2CYLqVaguBhk/7OtvbWJFf?= =?us-ascii?Q?+tmFYQIABHAvN5WLGJv1S4RQi5owheNn9v7suigE7riGGQrThG8mOsQwcrsT?= =?us-ascii?Q?hdID1OWr+gH/mGdNNiruZKffKvPaFZmB3F7gWQ3h8oB/0SKuCCcH15OAKVOP?= =?us-ascii?Q?wj1PwHP1rNgydsJh3cc04yuMUNkVw4k8Ms8ZoC2nkOo2oeh1JUW7d2mLZKW1?= =?us-ascii?Q?bKwUJEjdNCRUdVpQ4l44yVf8+OEm45Z0F9d2aAVrT533qQ7zxi2kQ7PAhPA8?= =?us-ascii?Q?66iX7U/ftV0Am8GOBiEPKypP64qSMYwzZH57kCdDQesQldAQlGhbgJ5ARg02?= =?us-ascii?Q?l2KMB/uXt2sK+iQyx71NVGMvO5Pygv5oAmr6YoNNnh3pab0b9KbLreRLpdnk?= =?us-ascii?Q?QbOQUZX1mjUV9nt2RXDL3XXVILCK5F/esmy/uLwRr2f9IShKetKtOu+Gogr6?= =?us-ascii?Q?GkmJq9JqqHsEu3/l56e9e58G7mNonewsecGb323vcSl/L00jL0vhqtpvZ+Vq?= =?us-ascii?Q?Dx3CW51JhCXuJjfLD/L9YQfGsIdM0Qplnn6GanGde6AmunS/+WlmniYK1zs3?= =?us-ascii?Q?x+jmzDZOdk1Y6VvhId9QCRvU2wqjCeBZH/pYU1KaaeAtr/d8KNd8OJdCjOQh?= =?us-ascii?Q?7+4IkxCl04AMmmuj6mThhw2DcvoOpgIGN3Ml85izcNP9y8Jlnh8yQVamgFqR?= =?us-ascii?Q?LIHmKRBld6gzCmgXK90o9rtHWDOMyMg/xLEHjBPkul+/l6HQlsP+eXsab1qq?= =?us-ascii?Q?9g4nWVnQ103dpBExNsdrZ+mXB3rNjJSo2Ly6j8/lGmV4qra2I7qh/DTMJypm?= =?us-ascii?Q?o2jrVLEPlBlGTP3EK6W+3Uq4yIkT1/BNL36VP7HQSz+B7tuw+LDs8sVTk6vr?= =?us-ascii?Q?r3unEXrCCNW/iFvikO0RK6eu2T5aqxm1VD52hdzjMzpybdmahbsvvPLRG75e?= =?us-ascii?Q?Ckj4ylGxS2MGs0MsKC2LO+2iwy2emVdDHa1P71kv8T+0rKE+6y5RQmoU3MiG?= =?us-ascii?Q?rj/RcZ5ALUZ7vFTPSw/s8bYvlZnSARy7c/G1QjJlqbIPc5gLb2z0Jx7ZgvZR?= =?us-ascii?Q?dKfp14nE2BpT7LD4FZAJmbgaNcAklQcyIrtXMKa+/5jVhr6aedgUz14rruQg?= =?us-ascii?Q?74XcTVa7mhXTjpyhPYMXuniEIjI2jfFbe/mu1xXrf8OHOO9r+HQt+BSZcUSk?= =?us-ascii?Q?Lvqwo9/9g/RXu7pQNqPIR6Wl6bx1HacBpeyZqj4iT03wDcGPtRJLi6JpHLWb?= =?us-ascii?Q?Vg9j60PFXqi6Xwx8pGC5nTzye9txjy3rKEgA4nxSyJhpmqPUoj9I93YtbViM?= =?us-ascii?Q?l3hGR0sg3rYz5VKJn3loVLjR7fQfEpA=3D?= X-Exchange-RoutingPolicyChecked: iZ+F4YnGQZdOYxNhSGxRqhgYsdI73eAyHVTkUTfaOYtZEWYt1d+ePDFrTHPYe5MGn87ap9AkwZN1DiAR0QKtrbQH/fA6nFt06PAXrHrjgY6s+dzpbCVb/hrzcBRnPt0fWfPBMBFGX6HcRsvFKPuFAkwn2v2AT/mxJBZIjokOeH+87piQLB8YpLqt8/2j227rdX/0kpog/B/3kWoi108p272hwCXGt+B6LjcsrCldgWGMELrlGSCNSzfAROqEUvH47IYZ3wnWoNAhC0523DSoIMLljuprxM7XH8gioZeRvjXqP3Z9nwXGLyDvjZLqztIvrGOI56hoOukZUqFCFKowtQ== X-MS-Exchange-CrossTenant-Network-Message-Id: 31dbdf1d-7fa3-48d5-bba3-08decd772e6d X-MS-Exchange-CrossTenant-AuthSource: DS4PPF0BAC23327.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 18 Jun 2026 20:21:29.8739 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: SK+CqBeMN+VSrHJDbQNnJc1puZhsJNlXiYCB1LVl7BTNDDviZ57x3LYENRzPnADQLsmfi5aKrHdRYSG7UwSVxEehyxydLXxUct7ofCJvuU4= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ5PPF5B09F0799 X-OriginatorOrg: intel.com On Sat, May 23, 2026 at 02:43:01AM -0700, Anisa Su wrote: > From: Ira Weiny > > DC DAX regions must allow memory to be added or removed dynamically. > In addition to the quantity of memory available the, > location of the memory within a DC partition is dynamic, based on the > extents offered by a device. CXL DAX regions must accommodate the > dynamic movement of this memory in the management of DAX regions and devices. > > Introduce the concept of a dynamic DAX region. Introduce > create_dynamic_ram_a_region() sysfs entry to create such regions. > Special case DC-capable regions to create a 0 sized seed DAX device > to maintain compatibility which requires a default DAX device to hold a > region reference. > > Indicate 0 byte available capacity until such time that capacity is > added. > > Dynamic regions complicate the range mapping of dax devices. There is no > known use case for range mapping on dynamic regions. Avoid the > complication by preventing range mapping of dax devices on dynamic > regions. > > Interleaving is deferred for now. Add checks. > > Based on an original patch by Navneet Singh. > > Signed-off-by: Ira Weiny > Hi Anisa, This change is needed and I think it belongs in this patch: diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 9fbcb2035600..e6d9a6238677 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -647,6 +647,8 @@ static ssize_t mode_show(struct device *dev, struct device_attribute *attr, desc = "ram"; else if (cxlr->mode == CXL_PARTMODE_PMEM) desc = "pmem"; + else if (cxlr->mode == CXL_PARTMODE_DYNAMIC_RAM_A) + desc = "dynamic_ram_a"; else desc = ""; IIUC That empty string default should be for an unset mode only. And, this makes the new type appear in cxl list -R -- Alison