Changes in Makefile

09d09e04 - cxl/dax: Create dax devices for CXL RAM regions

Fri, 10 Feb 2023 09:07:19 +0000

cxl/dax: Create dax devices for CXL RAM regionsWhile platform firmware takes some responsibility for mapping the RAMcapacity of CXL devices present at boot, the OS is responsible formapping the remainder and hot-added devices. Platform firmware is alsoresponsible for identifying the platform general purpose memory pool,typically DDR attached DRAM, and arranging for the remainder to be 'SoftReserved'. That reservation allows the CXL subsystem to route the memoryto core-mm via memory-hotplug (dax_kmem), or leave it for dedicatedaccess (device-dax).The new 'struct cxl_dax_region' object allows for a CXL memory resource(region) to be published, but also allow for udev and module policy toact on that event. It also prevents cxl_core.ko from having a moduleloading dependency on any drivers/dax/ modules.Tested-by: Fan Ni Reviewed-by: Dave Jiang Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/167602003896.1924368.10335442077318970468.stgit@dwillia2-xfh.jf.intel.comSigned-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile

83762cb5 - dax: Kill DEV_DAX_PMEM_COMPAT

Mon, 15 Nov 2021 21:20:57 +0000

dax: Kill DEV_DAX_PMEM_COMPATThe /sys/class/dax compatibility option has shipped in the kernel for 4years now which should be sufficient time for tools to abandon the oldABI in favor of the /sys/bus/dax device-model. Delete it now and see ifanyone screams.Since this compatibility option shipped there has been more reports ofusers being surprised by the compat ABI than surprised by the "new", sothe compat infrastructure has outlived its usefulness. Recall that/sys/bus/dax device-model is required for the dax kmem driver whichallows PMEM to be used as "System RAM".The following projects were known to have a dependency on /sys/class/daxand have dropped their dependency as of the listed version:- ndctl (including libndctl, daxctl, and libdaxctl): v64+- fio: v3.13+- pmdk: v1.5.2+As further evidence this option is no longer needed some distributionshave already stopped enabling CONFIG_DEV_DAX_PMEM_COMPAT.Cc: Ira Weiny Cc: Dave Jiang Reported-by: Vishal Verma Acked-by: Dave Hansen Reviewed-by: Jane Chu Link: https://lore.kernel.org/r/163701116195.3784476.726128179293466337.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile

c01044cc - ACPI: HMAT: refactor hmat_register_target_device to hmem_register_device

Tue, 13 Oct 2020 23:49:13 +0000

ACPI: HMAT: refactor hmat_register_target_device to hmem_register_deviceIn preparation for exposing "Soft Reserved" memory ranges without an HMAT,move the hmem device registration to its own compilation unit and make theimplementation generic.The generic implementation drops usage acpi_map_pxm_to_online_node() thatwas translating ACPI proximity domain values and instead relies onnuma_map_to_online_node() to determine the numa node for the device.[joao.m.martins@oracle.com: CONFIG_DEV_DAX_HMEM_DEVICES should depend on CONFIG_DAX=y] Link: https://lkml.kernel.org/r/8f34727f-ec2d-9395-cb18-969ec8a5d0d4@oracle.comSigned-off-by: Dan Williams Signed-off-by: Joao Martins Signed-off-by: Andrew Morton Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Ben Skeggs Cc: Borislav Petkov Cc: Brice Goglin Cc: Catalin Marinas Cc: Daniel Vetter Cc: Dave Hansen Cc: Dave Jiang Cc: David Airlie Cc: David Hildenbrand Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Ira Weiny Cc: Jason Gunthorpe Cc: Jeff Moyer Cc: Jia He Cc: Joao Martins Cc: Jonathan Cameron Cc: Michael Ellerman Cc: Mike Rapoport Cc: Paul Mackerras Cc: Pavel Tatashin Cc: Peter Zijlstra Cc: Rafael J. Wysocki Cc: Thomas Gleixner Cc: Tom Lendacky Cc: Vishal Verma Cc: Wei Yang Cc: Will Deacon Cc: Ard Biesheuvel Cc: Ard Biesheuvel Cc: Bjorn Helgaas Cc: Boris Ostrovsky Cc: Hulk Robot Cc: Jason Yan Cc: "Jérôme Glisse" Cc: Juergen Gross Cc: kernel test robot Cc: Randy Dunlap Cc: Stefano Stabellini Cc: Vivek Goyal Link: https://lkml.kernel.org/r/159643096584.4062302.5035370788475153738.stgit@dwillia2-desk3.amr.corp.intel.comLink: https://lore.kernel.org/r/158318761484.2216124.2049322072599482736.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Linus Torvalds List of files: /linux-6.15/drivers/dax/Makefile

a6c7f4c6 - device-dax: Add a driver for "hmem" devices

Thu, 07 Nov 2019 01:43:43 +0000

device-dax: Add a driver for "hmem" devicesPlatform firmware like EFI/ACPI may publish "hmem" platform devices.Such a device is a performance differentiated memory range likelyreserved for an application specific use case. The driver gives accessto 100% of the capacity via a device-dax mmap instance by default.However, if over-subscription and other kernel memory management isdesired the resulting dax device can be assigned to the core-mm via thekmem driver.This consumes "hmem" devices the producer of "hmem" devices is saved fora follow-on patch so that it can reference the new CONFIG_DEV_DAX_HMEMsymbol to gate performing the enumeration work.Reported-by: kbuild test robot Reviewed-by: Dave Hansen Signed-off-by: Dan Williams Acked-by: Thomas Gleixner Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/dax/Makefile

c221c0b0 - device-dax: "Hotplug" persistent memory for use like normal RAM

Mon, 25 Feb 2019 18:57:40 +0000

device-dax: "Hotplug" persistent memory for use like normal RAMThis is intended for use with NVDIMMs that are physically persistent(physically like flash) so that they can be used as a cost-effectiveRAM replacement. Intel Optane DC persistent memory is oneimplementation of this kind of NVDIMM.Currently, a persistent memory region is "owned" by a device driver,either the "Direct DAX" or "Filesystem DAX" drivers. These driversallow applications to explicitly use persistent memory, generallyby being modified to use special, new libraries. (DIMM-basedpersistent memory hardware/software is described in great detailhere: Documentation/nvdimm/nvdimm.txt).However, this limits persistent memory use to applications which*have* been modified. To make it more broadly usable, this driver"hotplugs" memory into the kernel, to be managed and used just likenormal RAM would be.To make this work, management software must remove the device frombeing controlled by the "Device DAX" infrastructure: echo dax0.0 > /sys/bus/dax/drivers/device_dax/unbindand then tell the new driver that it can bind to the device: echo dax0.0 > /sys/bus/dax/drivers/kmem/new_idAfter this, there will be a number of new memory sections visiblein sysfs that can be onlined, or that may get onlined by existingudev-initiated memory hotplug rules.This rebinding procedure is currently a one-way trip. Once memoryis bound to "kmem", it's there permanently and can not beunbound and assigned back to device_dax.The kmem driver will never bind to a dax device unless the deviceis *explicitly* bound to the driver. There are two reasons forthis: One, since it is a one-way trip, it can not be undone ifbound incorrectly. Two, the kmem driver destroys data on thedevice. Think of if you had good data on a pmem device. Itwould be catastrophic if you compile-in "kmem", but leave outthe "device_dax" driver. kmem would take over the device andwrite volatile data all over your good data.This inherits any existing NUMA information for the newly-addedmemory from the persistent memory device that came from thefirmware. On Intel platforms, the firmware has guarantees thatrequire each socket's persistent memory to be in a separatememory-only NUMA node. That means that this patch is not expectedto create NUMA nodes, but will simply hotplug memory into existingnodes.Because NUMA nodes are created, the existing NUMA APIs and toolsare sufficient to create policies for applications or memory areasto have affinity for or an aversion to using this memory.There is currently some metadata at the beginning of pmem regions.The section-size memory hotplug restrictions, plus this smallreserved area can cause the "loss" of a section or two of capacity.This should be fixable in follow-on patches. But, as a first step,losing 256MB of memory (worst case) out of hundreds of gigabytesis a good tradeoff vs. the required code to fix this up precisely.This calculation is also the reason we exportmemory_block_size_bytes().Signed-off-by: Dave Hansen Reviewed-by: Dan Williams Reviewed-by: Keith Busch Cc: Dave Jiang Cc: Ross Zwisler Cc: Vishal Verma Cc: Tom Lendacky Cc: Andrew Morton Cc: Michal Hocko Cc: linux-nvdimm@lists.01.orgCc: linux-kernel@vger.kernel.orgCc: linux-mm@kvack.orgCc: Huang Ying Cc: Fengguang Wu Cc: Borislav Petkov Cc: Bjorn Helgaas Cc: Yaowei Bai Cc: Takashi Iwai Cc: Jerome Glisse Reviewed-by: Vishal Verma Signed-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile

730926c3 - device-dax: Add /sys/class/dax backwards compatibility

Sun, 16 Jul 2017 20:51:53 +0000

device-dax: Add /sys/class/dax backwards compatibilityOn the expectation that some environments may not upgrade libdaxctl(userspace component that depends on the /sys/class/dax hierarchy),provide a default / legacy dax_pmem_compat driver. The dax_pmem_compatdriver implements the original /sys/class/dax sysfs layout rather than/sys/bus/dax. When userspace is upgraded it can blacklist this moduleand switch to the dax_pmem driver going forward.CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted accordingto the dax_pmem entry in Documentation/ABI/obsolete/.Signed-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile

51cf784c - device-dax: Start defining a dax bus model

Thu, 13 Jul 2017 00:58:21 +0000

device-dax: Start defining a dax bus modelTowards eliminating the dax_class, move the dax-device-attributeenabling to a new bus.c file in the core. The amount of codethrash of sub-sequent patches is reduced as no logic changes are made,just pure code movement.A temporary export of unregister_dex_dax() and dax_attribute_groups isneeded to preserve compilation, but those symbols become static again ina follow-on patch.Signed-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile

b2441318 - License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Wed, 01 Nov 2017 14:07:57 +0000

License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseMany source files in the tree are missing licensing information, whichmakes it harder for compliance tools to determine the correct license.By default all files without license information are under the defaultlicense of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'SPDX license identifier. The SPDX identifier is a legally bindingshorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart andPhilippe Ombredanne.How this work was done:Patches were generated and checked against linux-4.14-rc6 for a subset ofthe use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up caseswhere non-standard license headers were used, and references to licensehad to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied toa file was done in a spreadsheet of side by side results from of theoutput of two independent scanners (ScanCode & Windriver) producing SPDXtag:value files created by Philippe Ombredanne. Philippe prepared thebase worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 filesassessed. Kate Stewart did a file by file comparison of the scannerresults in the spreadsheet to determine which SPDX license identifier(s)to be applied to the file. She confirmed any determination that was notimmediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines).All documentation files were explicitly excluded.The following heuristics were used to determine which SPDX licenseidentifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time.In total, over 70 hours of logged manual review was done on thespreadsheet to determine the SPDX license identifiers to apply to thesource files by Kate, Philippe, Thomas and, in some cases, confirmationby lawyers working with the Linux Foundation.Kate also obtained a third independent scan of the 4.13 code base fromFOSSology, and compared selected files where the other two scannersdisagreed against that SPDX file, to see if there was new insights. TheWindriver scanner is based on an older version of FOSSology in part, sothey are related.Thomas did random spot checks in about 500 files from the spreadsheetsfor the uapi headers and agreed with SPDX license identifier in thefiles he inspected. For the non-uapi files Thomas did random spot checksin about 15000 files.In initial set of patches against 4.14-rc6, 3 files were found to havecopy/paste license identifier errors, and have been fixed to reflect thecorrect identifier.Additionally Philippe spent 10 hours this week doing a detailed manualinspection and review of the 12,461 patched files from the initial patchversion early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correctThis produced a worksheet with 20 files needing minor correction. Thisworksheet was then exported into 3 different .csv files for thedifferent types of files to be modified.These .csv files were then reviewed by Greg. Thomas wrote a script toparse the csv files and add the proper SPDX tag to the file, in theformat that the file expected. This script was further refined by Gregbased on the output to detect more types of files automatically and todistinguish between header and source .c files (which need differentcomment types.) Finally Greg ran the script using the .csv files togenerate the patches.Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman List of files: /linux-6.15/drivers/dax/Makefile

7b6be844 - dax: refactor dax-fs into a generic provider of 'struct dax_device' instances

Tue, 11 Apr 2017 16:49:49 +0000

dax: refactor dax-fs into a generic provider of 'struct dax_device' instancesWe want dax capable drivers to be able to publish a set of daxoperations [1]. However, we do not want to further abuse block_devicesto advertise these operations. Instead we will attach these operationsto a dax device and add a lookup mechanism to go from block device pathto a dax device. A dax capable driver like pmem or brd is responsiblefor registering a dax device, alongside a block device, and then a daxcapable filesystem is responsible for retrieving the dax device by pathname if it wants to call dax_operations.For now, we refactor the dax pseudo-fs to be a generic facility, ratherthan an implementation detail, of the device-dax use case. Where a "daxdevice" is just an inode + dax infrastructure, and "Device DAX" is amapping service layered on top of that base 'struct dax_device'."Filesystem DAX" is then a mapping service that layers a filesystem ontop of that same base device. Filesystem DAX is associated with ablock_device for now, but perhaps directly to a dax device in thefuture, or for new pmem-only filesystems.[1]: https://lkml.org/lkml/2017/1/19/880Suggested-by: Christoph Hellwig Signed-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile

ab68f262 - /dev/dax, pmem: direct access to persistent memory

Wed, 18 May 2016 16:15:08 +0000

/dev/dax, pmem: direct access to persistent memoryDevice DAX is the device-centric analogue of Filesystem DAX(CONFIG_FS_DAX). It allows memory ranges to be allocated and mappedwithout need of an intervening file system. Device DAX is strict,precise and predictable. Specifically this interface:1/ Guarantees fault granularity with respect to a given page size (pte,pmd, or pud) set at configuration time.2/ Enforces deterministic behavior by being strict about what faultscenarios are supported.For example, by forcing MADV_DONTFORK semantics and omitting MAP_PRIVATEsupport device-dax guarantees that a mapping always behaves/performs thesame once established. It is the "what you see is what you get" accessmechanism to differentiated memory vs filesystem DAX which hasfilesystem specific implementation semantics.Persistent memory is the first target, but the mechanism is alsotargeted for exclusive allocations of performance differentiated memoryranges.This commit is limited to the base device driver infrastructure toassociate a dax device with pmem range.Cc: Jeff Moyer Cc: Christoph Hellwig Cc: Andrew Morton Cc: Dave Hansen Cc: Ross Zwisler Reviewed-by: Johannes Thumshirn Signed-off-by: Dan Williams List of files: /linux-6.15/drivers/dax/Makefile