Commit Graph

4 Commits

Author SHA1 Message Date
Ard Biesheuvel cf8e865810 arch: Remove Itanium (IA-64) architecture
The Itanium architecture is obsolete, and an informal survey [0] reveals
that any residual use of Itanium hardware in production is mostly HP-UX
or OpenVMS based. The use of Linux on Itanium appears to be limited to
enthusiasts that occasionally boot a fresh Linux kernel to see whether
things are still working as intended, and perhaps to churn out some
distro packages that are rarely used in practice.

None of the original companies behind Itanium still produce or support
any hardware or software for the architecture, and it is listed as
'Orphaned' in the MAINTAINERS file, as apparently, none of the engineers
that contributed on behalf of those companies (nor anyone else, for that
matter) have been willing to support or maintain the architecture
upstream or even be responsible for applying the odd fix. The Intel
firmware team removed all IA-64 support from the Tianocore/EDK2
reference implementation of EFI in 2018. (Itanium is the original
architecture for which EFI was developed, and the way Linux supports it
deviates significantly from other architectures.) Some distros, such as
Debian and Gentoo, still maintain [unofficial] ia64 ports, but many have
dropped support years ago.

While the argument is being made [1] that there is a 'for the common
good' angle to being able to build and run existing projects such as the
Grid Community Toolkit [2] on Itanium for interoperability testing, the
fact remains that none of those projects are known to be deployed on
Linux/ia64, and very few people actually have access to such a system in
the first place. Even if there were ways imaginable in which Linux/ia64
could be put to good use today, what matters is whether anyone is
actually doing that, and this does not appear to be the case.

There are no emulators widely available, and so boot testing Itanium is
generally infeasible for ordinary contributors. GCC still supports IA-64
but its compile farm [3] no longer has any IA-64 machines. GLIBC would
like to get rid of IA-64 [4] too because it would permit some overdue
code cleanups. In summary, the benefits to the ecosystem of having IA-64
be part of it are mostly theoretical, whereas the maintenance overhead
of keeping it supported is real.

So let's rip off the band aid, and remove the IA-64 arch code entirely.
This follows the timeline proposed by the Debian/ia64 maintainer [5],
which removes support in a controlled manner, leaving IA-64 in a known
good state in the most recent LTS release. Other projects will follow
once the kernel support is removed.

[0] https://lore.kernel.org/all/CAMj1kXFCMh_578jniKpUtx_j8ByHnt=s7S+yQ+vGbKt9ud7+kQ@mail.gmail.com/
[1] https://lore.kernel.org/all/0075883c-7c51-00f5-2c2d-5119c1820410@web.de/
[2] https://gridcf.org/gct-docs/latest/index.html
[3] https://cfarm.tetaneutral.net/machines/list/
[4] https://lore.kernel.org/all/87bkiilpc4.fsf@mid.deneb.enyo.de/
[5] https://lore.kernel.org/all/ff58a3e76e5102c94bb5946d99187b358def688a.camel@physik.fu-berlin.de/

Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-09-11 08:13:17 +00:00
Huacai Chen b1121e2a18 ACPI: Add LoongArch support for ACPI_PROCESSOR/ACPI_NUMA
We are preparing to add new Loongson (based on LoongArch, not MIPS)
support. LoongArch use ACPI other than DT as its boot protocol, so
add its support for ACPI_PROCESSOR/ACPI_NUMA.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-07-16 19:09:20 +02:00
Dan Williams cf8741ac57 ACPI: NUMA: HMAT: Register "soft reserved" memory as an "hmem" device
Memory that has been tagged EFI_MEMORY_SP, and has performance
properties described by the ACPI HMAT is expected to have an application
specific consumer.

Those consumers may want 100% of the memory capacity to be reserved from
any usage by the kernel. By default, with this enabling, a platform
device is created to represent this differentiated resource.

The device-dax "hmem" driver claims these devices by default and
provides an mmap interface for the target application.  If the
administrator prefers, the hmem resource range can be made available to
the core-mm via the device-dax hotplug facility, kmem, to online the
memory with its own numa node.

This was tested with an emulated HMAT produced by qemu (with the pending
HMAT enabling patches), and "efi_fake_mem=8G@9G:0x40000" on the kernel
command line to mark the memory ranges associated with node2 and node3
as EFI_MEMORY_SP.

qemu numa configuration options:

-numa node,mem=4G,cpus=0-19,nodeid=0
-numa node,mem=4G,cpus=20-39,nodeid=1
-numa node,mem=4G,nodeid=2
-numa node,mem=4G,nodeid=3
-numa dist,src=0,dst=0,val=10
-numa dist,src=0,dst=1,val=21
-numa dist,src=0,dst=2,val=21
-numa dist,src=0,dst=3,val=21
-numa dist,src=1,dst=0,val=21
-numa dist,src=1,dst=1,val=10
-numa dist,src=1,dst=2,val=21
-numa dist,src=1,dst=3,val=21
-numa dist,src=2,dst=0,val=21
-numa dist,src=2,dst=1,val=21
-numa dist,src=2,dst=2,val=10
-numa dist,src=2,dst=3,val=21
-numa dist,src=3,dst=0,val=21
-numa dist,src=3,dst=1,val=21
-numa dist,src=3,dst=2,val=21
-numa dist,src=3,dst=3,val=10
-numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-latency,base-lat=10,latency=5
-numa hmat-lb,initiator=0,target=0,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=5
-numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-latency,base-lat=10,latency=10
-numa hmat-lb,initiator=0,target=1,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=10
-numa hmat-lb,initiator=0,target=2,hierarchy=memory,data-type=access-latency,base-lat=10,latency=15
-numa hmat-lb,initiator=0,target=2,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=15
-numa hmat-lb,initiator=0,target=3,hierarchy=memory,data-type=access-latency,base-lat=10,latency=20
-numa hmat-lb,initiator=0,target=3,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=20
-numa hmat-lb,initiator=1,target=0,hierarchy=memory,data-type=access-latency,base-lat=10,latency=10
-numa hmat-lb,initiator=1,target=0,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=10
-numa hmat-lb,initiator=1,target=1,hierarchy=memory,data-type=access-latency,base-lat=10,latency=5
-numa hmat-lb,initiator=1,target=1,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=5
-numa hmat-lb,initiator=1,target=2,hierarchy=memory,data-type=access-latency,base-lat=10,latency=15
-numa hmat-lb,initiator=1,target=2,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=15
-numa hmat-lb,initiator=1,target=3,hierarchy=memory,data-type=access-latency,base-lat=10,latency=20
-numa hmat-lb,initiator=1,target=3,hierarchy=memory,data-type=access-bandwidth,base-bw=20,bandwidth=20

Result:

[
  {
    "path":"\/platform\/hmem.1",
    "id":1,
    "size":"4.00 GiB (4.29 GB)",
    "align":2097152,
    "devices":[
      {
        "chardev":"dax1.0",
        "size":"4.00 GiB (4.29 GB)"
      }
    ]
  },
  {
    "path":"\/platform\/hmem.0",
    "id":0,
    "size":"4.00 GiB (4.29 GB)",
    "align":2097152,
    "devices":[
      {
        "chardev":"dax0.0",
        "size":"4.00 GiB (4.29 GB)"
      }
    ]
  }
]

[..]
240000000-43fffffff : Soft Reserved
  240000000-33fffffff : hmem.0
    240000000-33fffffff : dax0.0
  340000000-43fffffff : hmem.1
    340000000-43fffffff : dax1.0

Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-07 15:45:23 +01:00
Dan Williams c710fcc5d9 ACPI: NUMA: Establish a new drivers/acpi/numa/ directory
Currently hmat.c lives under an "hmat" directory which does not enhance
the description of the file. The initial motivation for giving hmat.c
its own directory was to delineate it as mm functionality in contrast to
ACPI device driver functionality.

As ACPI continues to play an increasing role in conveying
memory location and performance topology information to the OS take the
opportunity to co-locate these NUMA relevant tables in a combined
directory.

numa.c is renamed to srat.c and moved to drivers/acpi/numa/ along with
hmat.c.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-11-07 15:43:38 +01:00