kernel/linux.git/drivers/dax/Kconfig, branch v6.1.168

dax: remove CONFIG_DAX_DRIVER

2021-12-04T16:58:51+00:00

CONFIG_DAX_DRIVER only selects CONFIG_DAX now, so remove it. Signed-off-by: Christoph Hellwig Reviewed-by: Dan Williams Link: https://lore.kernel.org/r/20211129102203.2243509-4-hch@lst.de Signed-off-by: Dan Williams

dax: Kill DEV_DAX_PMEM_COMPAT

2021-11-25T03:21:35+00:00

The /sys/class/dax compatibility option has shipped in the kernel for 4 years now which should be sufficient time for tools to abandon the old ABI in favor of the /sys/bus/dax device-model. Delete it now and see if anyone screams. Since this compatibility option shipped there has been more reports of users being surprised by the compat ABI than surprised by the "new", so the compat infrastructure has outlived its usefulness. Recall that /sys/bus/dax device-model is required for the dax kmem driver which allows PMEM to be used as "System RAM". The following projects were known to have a dependency on /sys/class/dax and 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 distributions have 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.com Signed-off-by: Dan Williams

mm: fix phys_to_target_node() and memory_add_physaddr_to_nid() exports

2020-11-22T18:48:22+00:00

The core-mm has a default __weak implementation of phys_to_target_node() to mirror the weak definition of memory_add_physaddr_to_nid(). That symbol is exported for modules. However, while the export in mm/memory_hotplug.c exported the symbol in the configuration cases of: CONFIG_NUMA_KEEP_MEMINFO=y CONFIG_MEMORY_HOTPLUG=y ...and: CONFIG_NUMA_KEEP_MEMINFO=n CONFIG_MEMORY_HOTPLUG=y ...it failed to export the symbol in the case of: CONFIG_NUMA_KEEP_MEMINFO=y CONFIG_MEMORY_HOTPLUG=n Not only is that broken, but Christoph points out that the kernel should not be exporting any __weak symbol, which means that memory_add_physaddr_to_nid() example that phys_to_target_node() copied is broken too. Rework the definition of phys_to_target_node() and memory_add_physaddr_to_nid() to not require weak symbols. Move to the common arch override design-pattern of an asm header defining a symbol to replace the default implementation. The only common header that all memory_add_physaddr_to_nid() producing architectures implement is asm/sparsemem.h. In fact, powerpc already defines its memory_add_physaddr_to_nid() helper in sparsemem.h. Double-down on that observation and define phys_to_target_node() where necessary in asm/sparsemem.h. An alternate consideration that was discarded was to put this override in asm/numa.h, but that entangles with the definition of MAX_NUMNODES relative to the inclusion of linux/nodemask.h, and requires powerpc to grow a new header. The dependency on NUMA_KEEP_MEMINFO for DEV_DAX_HMEM_DEVICES is invalid now that the symbol is properly exported / stubbed in all combinations of CONFIG_NUMA_KEEP_MEMINFO and CONFIG_MEMORY_HOTPLUG. [dan.j.williams@intel.com: v4] Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com [dan.j.williams@intel.com: powerpc: fix create_section_mapping compile warning] Link: https://lkml.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: a035b6bf863e ("mm/memory_hotplug: introduce default phys_to_target_node() implementation") Reported-by: Randy Dunlap Reported-by: Thomas Gleixner Reported-by: kernel test robot Reported-by: Christoph Hellwig Signed-off-by: Dan Williams Signed-off-by: Andrew Morton Tested-by: Randy Dunlap Tested-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Reviewed-by: Christoph Hellwig Cc: Joao Martins Cc: Tony Luck Cc: Fenghua Yu Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Vishal Verma Cc: Stephen Rothwell Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds

ACPI: HMAT: attach a device for each soft-reserved range

2020-10-14T01:38:28+00:00

The hmem enabling in commit cf8741ac57ed ("ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device") only registered ranges to the hmem driver for each soft-reservation that also appeared in the HMAT. While this is meant to encourage platform firmware to "do the right thing" and publish an HMAT, the corollary is that platforms that fail to publish an accurate HMAT will strand memory from Linux usage. Additionally, the "efi_fake_mem" kernel command line option enabling will strand memory by default without an HMAT. Arrange for "soft reserved" memory that goes unclaimed by HMAT entries to be published as raw resource ranges for the hmem driver to consume. Include a module parameter to disable either this fallback behavior, or the hmat enabling from creating hmem devices. The module parameter requires the hmem device enabling to have unique name in the module namespace: "device_hmem". The driver depends on the architecture providing phys_to_target_node() which is only x86 via numa_meminfo() and arm64 via a generic memblock implementation. [joao.m.martins@oracle.com: require NUMA_KEEP_MEMINFO for phys_to_target_node()] Link: https://lkml.kernel.org/r/aaae71a7-4846-f5cc-5acf-cf05fdb1f2dc@oracle.com Signed-off-by: Dan Williams Signed-off-by: Joao Martins Signed-off-by: Andrew Morton Reviewed-by: Joao Martins Cc: Jonathan Cameron Cc: Brice Goglin Cc: Jeff Moyer Cc: Catalin Marinas Cc: Will Deacon Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Benjamin Herrenschmidt Cc: Ben Skeggs Cc: Borislav Petkov 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: Jia He 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: 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/159643098298.4062302.17587338161136144730.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds

ACPI: HMAT: refactor hmat_register_target_device to hmem_register_device

2020-10-14T01:38:27+00:00

In preparation for exposing "Soft Reserved" memory ranges without an HMAT, move the hmem device registration to its own compilation unit and make the implementation generic. The generic implementation drops usage acpi_map_pxm_to_online_node() that was translating ACPI proximity domain values and instead relies on numa_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.com Signed-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.com Link: https://lore.kernel.org/r/158318761484.2216124.2049322072599482736.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds

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

2019-11-07T14:45:00+00:00

Platform firmware like EFI/ACPI may publish "hmem" platform devices. Such a device is a performance differentiated memory range likely reserved for an application specific use case. The driver gives access to 100% of the capacity via a device-dax mmap instance by default. However, if over-subscription and other kernel memory management is desired the resulting dax device can be assigned to the core-mm via the kmem driver. This consumes "hmem" devices the producer of "hmem" devices is saved for a follow-on patch so that it can reference the new CONFIG_DEV_DAX_HMEM symbol 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

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21T08:50:46+00:00

Add SPDX license identifiers to all Make/Kconfig files which: - Have no license information of any form These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

drivers/dax: Allow to include DEV_DAX_PMEM as builtin

2019-05-07T14:48:06+00:00

This move the dependency to DEV_DAX_PMEM_COMPAT such that only if DEV_DAX_PMEM is built as module we can allow the compat support. This allows to test the new code easily in a emulation setup where we often build things without module support. Cc: Fixes: 730926c3b099 ("device-dax: Add /sys/class/dax backwards compatibility") Signed-off-by: Aneesh Kumar K.V Signed-off-by: Dan Williams

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

2019-02-28T18:41:23+00:00

This is intended for use with NVDIMMs that are physically persistent (physically like flash) so that they can be used as a cost-effective RAM replacement. Intel Optane DC persistent memory is one implementation 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 drivers allow applications to explicitly use persistent memory, generally by being modified to use special, new libraries. (DIMM-based persistent memory hardware/software is described in great detail here: 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 like normal RAM would be. To make this work, management software must remove the device from being controlled by the "Device DAX" infrastructure: echo dax0.0 > /sys/bus/dax/drivers/device_dax/unbind and then tell the new driver that it can bind to the device: echo dax0.0 > /sys/bus/dax/drivers/kmem/new_id After this, there will be a number of new memory sections visible in sysfs that can be onlined, or that may get onlined by existing udev-initiated memory hotplug rules. This rebinding procedure is currently a one-way trip. Once memory is bound to "kmem", it's there permanently and can not be unbound and assigned back to device_dax. The kmem driver will never bind to a dax device unless the device is *explicitly* bound to the driver. There are two reasons for this: One, since it is a one-way trip, it can not be undone if bound incorrectly. Two, the kmem driver destroys data on the device. Think of if you had good data on a pmem device. It would be catastrophic if you compile-in "kmem", but leave out the "device_dax" driver. kmem would take over the device and write volatile data all over your good data. This inherits any existing NUMA information for the newly-added memory from the persistent memory device that came from the firmware. On Intel platforms, the firmware has guarantees that require each socket's persistent memory to be in a separate memory-only NUMA node. That means that this patch is not expected to create NUMA nodes, but will simply hotplug memory into existing nodes. Because NUMA nodes are created, the existing NUMA APIs and tools are sufficient to create policies for applications or memory areas to 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 small reserved 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 gigabytes is a good tradeoff vs. the required code to fix this up precisely. This calculation is also the reason we export memory_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.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: 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

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

2019-01-07T05:41:57+00:00

On 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_compat driver implements the original /sys/class/dax sysfs layout rather than /sys/bus/dax. When userspace is upgraded it can blacklist this module and switch to the dax_pmem driver going forward. CONFIG_DEV_DAX_PMEM_COMPAT and supporting code will be deleted according to the dax_pmem entry in Documentation/ABI/obsolete/. Signed-off-by: Dan Williams