So called "soft-reserved" memory is an EFI conventional memory range
with the EFI_MEMORY_SP attribute set. That attribute indicates that the
memory is not part of the platform general purpose memory pool and may
want some consideration from the system administrator about whether to
keep that memory set aside for dedicated access through device-dax (map
a device file), or assigned to the page allocator as another general
purpose memory node target.
Absent an ACPI HMAT table the default device-dax registration creates
coarse grained devices that are delineated by EFI Memory Map entries.
With the HMAT the devices are delineated by the finer grained ranges
associated with the proximity domain of the memory target. I.e. the HMAT
describes the properties of performance differentiated memory and each
unique performance description results in a unique target proximity
domain where each memory proximity domain has an associated SRAT entry
that delineates the address range.
The intent was that SRAT-defined device-dax instances are registered
first. Then any left-over address range with the EFI_MEMORY_SP
attribute, but not covered by the SRAT, would have a coarse grained
device-dax instance established. However, the scheme to detect what
ranges are left to be assigned to a device was buggy and resulted in
multiple overlapping device-dax instances. Fix this by using explicit
tracking for which ranges have been handled.
Now, this new approach may leave memory stranded in the presence of
broken platform firmware that fails to fully describe all EFI_MEMORY_SP
ranges in the HMAT. That requires a deeper fix if it becomes a problem
in practice.
Reported-by: "Tallam Mahendra Kumar" <tallam.mahendra.kumar@intel.com>
Reported-by: Mustafa Hajeer <mustafa.hajeer@intel.com>
Debugged-by: Vishal Verma <vishal.l.verma@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/166890823379.4183293.15333502171004313377.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Pull nvdimm updates from Dan Williams:
"Some small cleanups and fixes in and around the nvdimm subsystem. The
most significant change is a regression fix for nvdimm namespace
(volume) creation when the namespace size is smaller than 2MB/
Summary:
- Fix nvdimm namespace creation on platforms that do not publish
associated 'DIMM' metadata for a persistent memory region.
- Miscellaneous fixes and cleanups"
* tag 'libnvdimm-for-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
ACPI: HMAT: Release platform device in case of platform_device_add_data() fails
dax: Remove usage of the deprecated ida_simple_xxx API
libnvdimm/region: Allow setting align attribute on regions without mappings
nvdimm/namespace: Fix comment typo
nvdimm: make __nvdimm_security_overwrite_query static
nvdimm/region: Fix kernel-doc
nvdimm/namespace: drop unneeded temporary variable in size_store()
nvdimm/namespace: return uuid_null only once in nd_dev_to_uuid()
The platform device is not released when platform_device_add_data()
fails. And platform_device_put() perfom one more pointer check than
put_device() to check for errors in the 'pdev' pointer.
Use platform_device_put() to release platform device in
platform_device_add()/platform_device_add_data()/
platform_device_add_resources() error case.
Fixes: c01044cc81 ("ACPI: HMAT: refactor hmat_register_target_device to hmem_register_device")
Signed-off-by: Lin Yujun <linyujun809@huawei.com>
Link: https://lore.kernel.org/r/20220914033755.99924-1-linyujun809@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The "hmem" platform-devices that are created to represent the
platform-advertised "Soft Reserved" memory ranges end up inserting a
resource that causes the iomem_resource tree to look like this:
340000000-43fffffff : hmem.0
340000000-43fffffff : Soft Reserved
340000000-43fffffff : dax0.0
This is because insert_resource() reparents ranges when they completely
intersect an existing range.
This matters because code that uses region_intersects() to scan for a
given IORES_DESC will only check that top-level 'hmem.0' resource and
not the 'Soft Reserved' descendant.
So, to support EINJ (via einj_error_inject()) to inject errors into
memory hosted by a dax-device, be sure to describe the memory as
IORES_DESC_SOFT_RESERVED. This is a follow-on to:
commit b13a3e5fd4 ("ACPI: APEI: Fix _EINJ vs EFI_MEMORY_SP")
...that fixed EINJ support for "Soft Reserved" ranges in the first
instance.
Fixes: 262b45ae3a ("x86/efi: EFI soft reservation to E820 enumeration")
Reported-by: Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>
Tested-by: Ricardo Sandoval Torres <ricardo.sandoval.torres@intel.com>
Cc: <stable@vger.kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Omar Avelar <omar.avelar@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mark Gross <markgross@kernel.org>
Link: https://lore.kernel.org/r/166397075670.389916.7435722208896316387.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
