From patchwork Thu Dec 14 07:37:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 13492517 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="DHFjAJPT" Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7686DA3; Wed, 13 Dec 2023 23:38:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702539492; x=1734075492; h=from:subject:date:message-id:mime-version: content-transfer-encoding:to:cc; bh=h6iwtR+Emw2EX9lZjGEXRQCb3JKoPyQmhXB1JkGLNZE=; b=DHFjAJPTQQqzUfMwsqBd71kL8avEX6nkCsuX6jPY4NCUrGjVONKIeMFq aSn/UJtPnd0u0B0NB3zbss/gTwSlKqLhftK7WMmc8tDpBm7pnMfsqKTpJ fvuEgyzS/o6XinjjFAb1ynqcGMzxyeUzupyEjk0TE3euOskGU2iyIDPYR wsnXCMYCOF6GkpH0ZCYf2JG3d+okEwBM7msml6/bJ4akskSRmVM+M2z/K RKlTsZdCXmoFqDs1rTmmZm4G3vkUyV597cay07nQwOfyUbKJORHKOqMlD vO+OxFcs4xRSTmfoO/kOehLKaiOEKYaTieHk+L/P0J/AOTZAYuxl0hE9a A==; X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="481275504" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="481275504" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:12 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10923"; a="723972055" X-IronPort-AV: E=Sophos;i="6.04,274,1695711600"; d="scan'208";a="723972055" Received: from llblake-mobl1.amr.corp.intel.com (HELO [192.168.1.200]) ([10.213.191.124]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Dec 2023 23:38:10 -0800 From: Vishal Verma Subject: [PATCH v5 0/4] Add DAX ABI for memmap_on_memory Date: Thu, 14 Dec 2023 00:37:53 -0700 Message-Id: <20231214-vv-dax_abi-v5-0-3f7b006960b4@intel.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIANGwemUC/3XM0QqCMBTG8VeJXbfYOZtTu+o9ImLOsxyUhsowx Hdv2o0Kca6+A7//yDpqPXXsfBhZS8F3vqnjSI4HZitTP4j7Mm6GAiUITHgIvDTD3RSeQ2oQcqu 0SDWL4N2S88MSu97irnzXN+1naQeYv78MCr3OBOCCq1RRkWWEAuzF1z09T7Z5sTkT8D/FSJ2Kh 1LqUmR7KlcUYENlpMY6bS0UJeVuT9Wa4oaqSEEmkCaZEzbHNZ2m6QsSnChrVQEAAA== To: Dan Williams , Vishal Verma , Dave Jiang , Andrew Morton , Oscar Salvador Cc: linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, David Hildenbrand , Dave Hansen , Huang Ying , Greg Kroah-Hartman , linux-mm@kvack.org, Joao Martins , Michal Hocko , Li Zhijian , Jonathan Cameron X-Mailer: b4 0.13-dev-433a8 X-Developer-Signature: v=1; a=openpgp-sha256; l=3873; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=h6iwtR+Emw2EX9lZjGEXRQCb3JKoPyQmhXB1JkGLNZE=; b=owGbwMvMwCXGf25diOft7jLG02pJDKlVG+499hN/bHjHzIXZ4f2aqSon9dUneh0P2eQcxcVfK /DPnkeoo5SFQYyLQVZMkeXvno+Mx+S25/MEJjjCzGFlAhnCwMUpABPJtWL4n2F/7nClCXdxvPpS YYsUNav9Z7eYdszbHpJ1n++8vc6BPQz/fWdYypxe3vOiMflFb6D3rHenfu58/z3m1ls3/dQ1b1e o8gAA X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF The DAX drivers were missing sysfs ABI documentation entirely. Add this missing documentation for the sysfs ABI for DAX regions and Dax devices in patch 1. Switch to guard(device) semantics for Scope Based Resource Management for device_{lock,unlock} flows in drivers/dax/bus.c in patch 2. Export mhp_supports_memmap_on_memory() in patch 3. Add a new ABI for toggling memmap_on_memory semantics in patch 4. The missing ABI was spotted in [1], this series is a split of the new ABI additions behind the initial documentation creation. [1]: https://lore.kernel.org/linux-cxl/651f27b728fef_ae7e7294b3@dwillia2-xfh.jf.intel.com.notmuch/ --- This series depends on [2] which adds the definition for guard(device). [2]: https://lore.kernel.org/r/170250854466.1522182.17555361077409628655.stgit@dwillia2-xfh.jf.intel.com --- Other Logistics - Andrew, would you prefer patch 3 to go through mm? Or through the dax tree with an mm ack? The remaining patches are all contained to dax, but do depend on the memmap_on_memory set that is currently in mm-stable. --- Changes in v5: - Export and check mhp_supports_memmap_on_memory() in the DAX sysfs ABI (David) - Obtain dax_drv under the device lock (Ying) - Check dax_drv for NULL before dereferencing it (Ying) - Clean up some repetition in sysfs-bus-dax documentation entries (Jonathan) - A few additional cleanups enabled by guard(device) (Jonathan) - Drop the DEFINE_GUARD() part of patch 2, add dependency on Dan's patch above so it can be backported / applied separately (Jonathan, Dan) - Link to v4: https://lore.kernel.org/r/20231212-vv-dax_abi-v4-0-1351758f0c92@intel.com Changes in v4: - Hold the device lock when checking if the dax_dev is bound to kmem (Ying, Dan) - Remove dax region checks (and locks) as they were unnecessary. - Introduce guard(device) for device lock/unlock (Dan) - Convert the rest of drivers/dax/bus.c to guard(device) - Link to v3: https://lore.kernel.org/r/20231211-vv-dax_abi-v3-0-acf6cc1bde9f@intel.com Changes in v3: - Fix typo in ABI docs (Zhijian Li) - Add kernel config and module parameter dependencies to the ABI docs entry (David Hildenbrand) - Ensure kmem isn't active when setting the sysfs attribute (Ying Huang) - Simplify returning from memmap_on_memory_store() - Link to v2: https://lore.kernel.org/r/20231206-vv-dax_abi-v2-0-f4f4f2336d08@intel.com Changes in v2: - Fix CC lists, patch 1/2 didn't get sent correctly in v1 - Link to v1: https://lore.kernel.org/r/20231206-vv-dax_abi-v1-0-474eb88e201c@intel.com Cc: Cc: Cc: Cc: David Hildenbrand Cc: Dave Hansen Cc: Huang Ying Cc: Greg Kroah-Hartman Cc: To: Dan Williams To: Vishal Verma To: Dave Jiang To: Andrew Morton To: Oscar Salvador --- Vishal Verma (4): Documentatiion/ABI: Add ABI documentation for sys-bus-dax dax/bus: Use guard(device) in sysfs attribute helpers mm/memory_hotplug: export mhp_supports_memmap_on_memory() dax: add a sysfs knob to control memmap_on_memory behavior include/linux/memory_hotplug.h | 6 ++ drivers/dax/bus.c | 181 +++++++++++++++++--------------- mm/memory_hotplug.c | 17 ++- Documentation/ABI/testing/sysfs-bus-dax | 153 +++++++++++++++++++++++++++ 4 files changed, 262 insertions(+), 95 deletions(-) --- base-commit: a6e0c2ca980d75d5ac6b2902c5c0028eaf094db3 change-id: 20231025-vv-dax_abi-17a219c46076 Best regards,