From patchwork Tue Dec 12 19:08:30 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: 13489794 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XUwpJqQV" Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4163791; Tue, 12 Dec 2023 11:08:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1702408129; x=1733944129; h=from:date:subject:mime-version:content-transfer-encoding: message-id:references:in-reply-to:to:cc; bh=j9znkpM/52KvUGuun0RJffYF/wG7fdqoc+th2+hzW9E=; b=XUwpJqQVSc2fSHpXJ0fCAYWWf3agy3NELLQxoLTjQjrxr6waed5FrgnZ Ml79SWkG3vgfv39y9bg8g4bp8J6YpgwGPtbLi4iMmbb5pE37HvRFUJFuH aEJcws0aJFCrKTYMMIt51psKWzQn0RtvXArAIyTtoKOc17YMiGsc4JGRp dv2WuPSK5P+GdYfcXO5lt59DFoqNBA72ElvIVvPtp3bVoHmKUzUUqd09M z+0rpkUTrD3vcZwWfAEAcIpYIgBMw8NB6nVJ+T522rMuPf8aF4x7t2k/z Yfh1yLuXC4gvPrH1ayJzhxGOAkz0rcu2Mv/gpKCfy8gCEbpPoBk0yf+WD A==; X-IronPort-AV: E=McAfee;i="6600,9927,10922"; a="13550590" X-IronPort-AV: E=Sophos;i="6.04,271,1695711600"; d="scan'208";a="13550590" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Dec 2023 11:08:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10922"; a="844017858" X-IronPort-AV: E=Sophos;i="6.04,271,1695711600"; d="scan'208";a="844017858" Received: from cmperez2-mobl2.amr.corp.intel.com (HELO [192.168.1.200]) ([10.212.66.25]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Dec 2023 11:08:46 -0800 From: Vishal Verma Date: Tue, 12 Dec 2023 12:08:30 -0700 Subject: [PATCH v4 1/3] Documentatiion/ABI: Add ABI documentation for sys-bus-dax Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20231212-vv-dax_abi-v4-1-1351758f0c92@intel.com> References: <20231212-vv-dax_abi-v4-0-1351758f0c92@intel.com> In-Reply-To: <20231212-vv-dax_abi-v4-0-1351758f0c92@intel.com> To: Dan Williams , Vishal Verma , Dave Jiang Cc: linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, David Hildenbrand , Dave Hansen , Huang Ying X-Mailer: b4 0.13-dev-433a8 X-Developer-Signature: v=1; a=openpgp-sha256; l=6438; i=vishal.l.verma@intel.com; h=from:subject:message-id; bh=j9znkpM/52KvUGuun0RJffYF/wG7fdqoc+th2+hzW9E=; b=owGbwMvMwCXGf25diOft7jLG02pJDKkV6/c++sH4JHK37SyXiZ/7HR3mC534f+l0kHObiG/pe qUI2+NXOkpZGMS4GGTFFFn+7vnIeExuez5PYIIjzBxWJpAhDFycAjCRi3UM/9NOc/pObtnVeiTc W/ecyKX5vVmLHsiH6qS/3FESNuHUxBCG/w4WfWKJP3pcmPjWPFT6OZXPWXbKg5eLc45cZap9FhA pyw0A X-Developer-Key: i=vishal.l.verma@intel.com; a=openpgp; fpr=F8682BE134C67A12332A2ED07AFA61BEA3B84DFF Add the missing sysfs ABI documentation for the device DAX subsystem. Various ABI attributes under this have been present since v5.1, and more have been added over time. In preparation for adding a new attribute, add this file with the historical details. Cc: Dan Williams Signed-off-by: Vishal Verma --- Documentation/ABI/testing/sysfs-bus-dax | 151 ++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-dax b/Documentation/ABI/testing/sysfs-bus-dax new file mode 100644 index 000000000000..a61a7b186017 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-dax @@ -0,0 +1,151 @@ +What: /sys/bus/dax/devices/daxX.Y/align +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RW) Provides a way to specify an alignment for a dax device. + Values allowed are constrained by the physical address ranges + that back the dax device, and also by arch requirements. + +What: /sys/bus/dax/devices/daxX.Y/mapping +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (WO) Provides a way to allocate a mapping range under a dax + device. Specified in the format -. + +What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/start +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) A dax device may have multiple constituent discontiguous + address ranges. These are represented by the different + 'mappingX' subdirectories. The 'start' attribute indicates the + start physical address for the given range. + +What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/end +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) A dax device may have multiple constituent discontiguous + address ranges. These are represented by the different + 'mappingX' subdirectories. The 'end' attribute indicates the + end physical address for the given range. + +What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/page_offset +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) A dax device may have multiple constituent discontiguous + address ranges. These are represented by the different + 'mappingX' subdirectories. The 'page_offset' attribute indicates the + offset of the current range in the dax device. + +What: /sys/bus/dax/devices/daxX.Y/resource +Date: June, 2019 +KernelVersion: v5.3 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The resource attribute indicates the starting physical + address of a dax device. In case of a device with multiple + constituent ranges, it indicates the starting address of the + first range. + +What: /sys/bus/dax/devices/daxX.Y/size +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RW) The size attribute indicates the total size of a dax + device. For creating subdivided dax devices, or for resizing + an existing device, the new size can be written to this as + part of the reconfiguration process. + +What: /sys/bus/dax/devices/daxX.Y/numa_node +Date: November, 2019 +KernelVersion: v5.5 +Contact: nvdimm@lists.linux.dev +Description: + (RO) If NUMA is enabled and the platform has affinitized the + backing device for this dax device, emit the CPU node + affinity for this device. + +What: /sys/bus/dax/devices/daxX.Y/target_node +Date: February, 2019 +KernelVersion: v5.1 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The target-node attribute is the Linux numa-node that a + device-dax instance may create when it is online. Prior to + being online the device's 'numa_node' property reflects the + closest online cpu node which is the typical expectation of a + device 'numa_node'. Once it is online it becomes its own + distinct numa node. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/available_size +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The available_size attribute tracks available dax region + capacity. This only applies to volatile hmem devices, not pmem + devices, since pmem devices are defined by nvdimm namespace + boundaries. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/size +Date: July, 2017 +KernelVersion: v5.1 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The size attribute indicates the size of a given dax region + in bytes. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/align +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The align attribute indicates alignment of the dax region. + Changes on align may not always be valid, when say certain + mappings were created with 2M and then we switch to 1G. This + validates all ranges against the new value being attempted, post + resizing. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/seed +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The seed device is a concept for dynamic dax regions to be + able to split the region amongst multiple sub-instances. The + seed device, similar to libnvdimm seed devices, is a device + that starts with zero capacity allocated and unbound to a + driver. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/create +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (RW) The create interface to the dax region provides a way to + create a new unconfigured dax device under the given region, which + can then be configured (with a size etc.) and then probed. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/delete +Date: October, 2020 +KernelVersion: v5.10 +Contact: nvdimm@lists.linux.dev +Description: + (WO) The delete interface for a dax region provides for deletion + of any 0-sized and idle dax devices. + +What: $(readlink -f /sys/bus/dax/devices/daxX.Y)/../dax_region/id +Date: July, 2017 +KernelVersion: v5.1 +Contact: nvdimm@lists.linux.dev +Description: + (RO) The id attribute indicates the region id of a dax region.