The patch titled
Subject: Documentatiion/ABI: add ABI documentation for sys-bus-dax
has been added to the -mm mm-unstable branch. Its filename is
documentatiion-abi-add-abi-documentation-for-sys-bus-dax.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/documentatiion-abi-add-abi-documentation-for-sys-bus-dax.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing
your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Vishal Verma <[email protected]>
Subject: Documentatiion/ABI: add ABI documentation for sys-bus-dax
Date: Wed, 24 Jan 2024 12:03:48 -0800
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.
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Vishal Verma <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Huang Ying <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Li Zhijian <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: <[email protected]>
Cc: Oscar Salvador <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
Documentation/ABI/testing/sysfs-bus-dax | 136 ++++++++++++++++++++++
1 file changed, 136 insertions(+)
--- /dev/null
+++ a/Documentation/ABI/testing/sysfs-bus-dax
@@ -0,0 +1,136 @@
+What: /sys/bus/dax/devices/daxX.Y/align
+Date: October, 2020
+KernelVersion: v5.10
+Contact: [email protected]
+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: [email protected]
+Description:
+ (WO) Provides a way to allocate a mapping range under a dax
+ device. Specified in the format <start>-<end>.
+
+What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/start
+What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/end
+What: /sys/bus/dax/devices/daxX.Y/mapping[0..N]/page_offset
+Date: October, 2020
+KernelVersion: v5.10
+Contact: [email protected]
+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. The 'end' attribute
+ indicates the end physical address for the given range. 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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+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: [email protected]
+Description:
+ (RO) The id attribute indicates the region id of a dax region.
_
Patches currently in -mm which might be from [email protected] are
dax-busc-replace-driver-core-lock-usage-by-a-local-rwsem.patch
dax-busc-replace-several-sprintf-with-sysfs_emit.patch
documentatiion-abi-add-abi-documentation-for-sys-bus-dax.patch
mm-memory_hotplug-export-mhp_supports_memmap_on_memory.patch
dax-add-a-sysfs-knob-to-control-memmap_on_memory-behavior.patch
