linux-stable/drivers/pci
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The Itanium architecture is obsolete, and an informal survey [0] reveals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
..
controller pci-v6.6-changes 2023-08-30 20:23:07 -07:00
endpoint Merge branch 'pci/misc' 2023-08-29 11:03:57 -05:00
hotplug powerpc updates for 6.6 2023-08-31 12:43:10 -07:00
msi PCI: Fix typos in docs and comments 2023-08-25 08:15:38 -05:00
pcie Merge branch 'pci/misc' 2023-08-29 11:03:57 -05:00
switch PCI: switchtec: Add support for PCIe Gen5 devices 2023-08-09 14:16:44 -05:00
access.c PCI: Simplify pcie_capability_clear_and_set_word() control flow 2023-08-25 08:16:10 -05:00
ats.c PCI: Enable PASID only when ACS RR & UF enabled on upstream path 2022-11-03 15:47:47 +01:00
bus.c Devicetree updates for v6.6: 2023-08-30 16:59:03 -07:00
doe.c PCI/DOE: Fix destroy_work_on_stack() race 2023-07-27 15:20:47 -05:00
ecam.c
host-bridge.c
iov.c PCI/IOV: Use pci_dev_id() to simplify the code 2023-08-07 16:15:39 -05:00
irq.c PCI: Check for alloc failure in pci_request_irq() 2022-11-21 16:55:18 -06:00
Kconfig PCI: Fix CONFIG_PCI_DYNAMIC_OF_NODES kconfig dependencies 2023-09-05 12:42:28 -05:00
Makefile PCI: Create device tree node for bridge 2023-08-22 14:56:09 -05:00
mmap.c
of.c Devicetree updates for v6.6: 2023-08-30 16:59:03 -07:00
of_property.c PCI: Create device tree node for bridge 2023-08-22 14:56:09 -05:00
p2pdma.c PCI: Fix typos in docs and comments 2023-08-25 08:15:38 -05:00
pci-acpi.c PCI/ACPI: Call _REG when transitioning D-states 2023-06-23 12:28:08 -05:00
pci-bridge-emul.c PCI: pci-bridge-emul: Set position of PCI capabilities to real HW value 2022-08-25 12:07:56 +02:00
pci-bridge-emul.h PCI: pci-bridge-emul: Set position of PCI capabilities to real HW value 2022-08-25 12:07:56 +02:00
pci-driver.c PCI: Simplify pci_dev_driver() 2023-08-25 08:15:29 -05:00
pci-label.c
pci-mid.c
pci-pf-stub.c
pci-stub.c
pci-sysfs.c PCI/sysfs: Make I/O resource depend on HAS_IOPORT 2023-07-18 16:56:58 -05:00
pci.c Merge branch 'pci/misc' 2023-08-29 11:03:57 -05:00
pci.h pci-v6.6-changes 2023-08-30 20:23:07 -07:00
probe.c PCI: Free released resource after coalescing 2023-09-06 12:19:29 -05:00
proc.c
quirks.c Revert "PCI: Mark NVIDIA T4 GPUs to avoid bus reset" 2023-09-08 15:11:45 -05:00
remove.c PCI: Create device tree node for bridge 2023-08-22 14:56:09 -05:00
rom.c
search.c
setup-bus.c PCI: Fix typos in docs and comments 2023-08-25 08:15:38 -05:00
setup-irq.c
setup-res.c PCI: Fix printk field formatting 2023-08-25 08:15:08 -05:00
slot.c PCI/sysfs: Constify struct kobj_type pci_slot_ktype 2023-02-16 12:00:25 -06:00
syscall.c PCI: Use consistent put_user() pointer types 2023-08-25 08:15:13 -05:00
vc.c
vgaarb.c arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
vpd.c PCI/VPD: Add runtime power management to sysfs interface 2023-08-11 14:19:16 -05:00
xen-pcifront.c x86: always initialize xen-swiotlb when xen-pcifront is enabling 2023-07-31 17:54:27 +02:00