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[00/11] x86: 32-bit cleanups

Message ID 20241204103042.1904639-1-arnd@kernel.org (mailing list archive)
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Series x86: 32-bit cleanups | expand

Message

Arnd Bergmann Dec. 4, 2024, 10:30 a.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

While looking at 32-bit arm cleanups, I came across some related topics
on x86 and ended up making a series for those as well.

Primarily this is about running 32-bit kernels on 64-bit hardware,
which usually works but should probably be discouraged more clearly by
only providing support for features that are used on real 32-bit hardware:

I found only a few 2003-era high-end servers (HP DL740 and DL760 G2)
that were the only possible remaining uses of HIGHMEM64G and BIGSMP after
the removal of 32-bit NUMA machines in 2014. Similary, there is only
one generation of hardware with support for VT-x.  All these features
can be removed without hurting users.

In the CPU selection, building a 32-bit kernel optimized for AMD K8
or Intel Core2 is anachronistic, so instead only 32-bit CPU types need
to be offered as optimization targets. The "generic" target on 64-bit
turned out to be slightly broken, so I included a fix for that as well,
replacing the compiler default target with an intentional selection
between the useful levels.

Arnd Bergmann (11):
  x86/Kconfig: Geode CPU has cmpxchg8b
  x86: drop 32-bit "bigsmp" machine support
  x86: Kconfig.cpu: split out 64-bit atom
  x86: split CPU selection into 32-bit and 64-bit
  x86: remove HIGHMEM64G support
  x86: drop SWIOTLB and PHYS_ADDR_T_64BIT for PAE
  x86: drop support for CONFIG_HIGHPTE
  x86: document X86_INTEL_MID as 64-bit-only
  x86: rework CONFIG_GENERIC_CPU compiler flags
  x86: remove old STA2x11 support
  x86: drop 32-bit KVM host support

 Documentation/admin-guide/kdump/kdump.rst     |   4 -
 .../admin-guide/kernel-parameters.txt         |  11 -
 Documentation/arch/x86/usb-legacy-support.rst |  11 +-
 arch/x86/Kconfig                              | 119 ++-------
 arch/x86/Kconfig.cpu                          | 130 +++++++---
 arch/x86/Makefile                             |  10 +-
 arch/x86/Makefile_32.cpu                      |   3 +-
 arch/x86/configs/xen.config                   |   2 -
 arch/x86/include/asm/page_32_types.h          |   4 +-
 arch/x86/include/asm/pgalloc.h                |   5 -
 arch/x86/include/asm/sta2x11.h                |  13 -
 arch/x86/include/asm/vermagic.h               |   4 -
 arch/x86/kernel/apic/Makefile                 |   3 -
 arch/x86/kernel/apic/apic.c                   |   3 -
 arch/x86/kernel/apic/bigsmp_32.c              | 105 --------
 arch/x86/kernel/apic/local.h                  |  13 -
 arch/x86/kernel/apic/probe_32.c               |  29 ---
 arch/x86/kernel/head32.c                      |   3 -
 arch/x86/kvm/Kconfig                          |   6 +-
 arch/x86/kvm/Makefile                         |   4 +-
 arch/x86/kvm/cpuid.c                          |   9 +-
 arch/x86/kvm/emulate.c                        |  34 +--
 arch/x86/kvm/fpu.h                            |   4 -
 arch/x86/kvm/hyperv.c                         |   5 +-
 arch/x86/kvm/i8254.c                          |   4 -
 arch/x86/kvm/kvm_cache_regs.h                 |   2 -
 arch/x86/kvm/kvm_emulate.h                    |   8 -
 arch/x86/kvm/lapic.c                          |   4 -
 arch/x86/kvm/mmu.h                            |   4 -
 arch/x86/kvm/mmu/mmu.c                        | 134 ----------
 arch/x86/kvm/mmu/mmu_internal.h               |   9 -
 arch/x86/kvm/mmu/paging_tmpl.h                |   9 -
 arch/x86/kvm/mmu/spte.h                       |   5 -
 arch/x86/kvm/mmu/tdp_mmu.h                    |   4 -
 arch/x86/kvm/smm.c                            |  19 --
 arch/x86/kvm/svm/sev.c                        |   2 -
 arch/x86/kvm/svm/svm.c                        |  23 +-
 arch/x86/kvm/svm/vmenter.S                    |  20 --
 arch/x86/kvm/trace.h                          |   4 -
 arch/x86/kvm/vmx/main.c                       |   2 -
 arch/x86/kvm/vmx/nested.c                     |  24 +-
 arch/x86/kvm/vmx/vmcs.h                       |   2 -
 arch/x86/kvm/vmx/vmenter.S                    |  25 +-
 arch/x86/kvm/vmx/vmx.c                        | 117 +--------
 arch/x86/kvm/vmx/vmx.h                        |  23 +-
 arch/x86/kvm/vmx/vmx_ops.h                    |   7 -
 arch/x86/kvm/vmx/x86_ops.h                    |   2 -
 arch/x86/kvm/x86.c                            |  74 +-----
 arch/x86/kvm/x86.h                            |   4 -
 arch/x86/kvm/xen.c                            |  61 ++---
 arch/x86/mm/init_32.c                         |   9 +-
 arch/x86/mm/pgtable.c                         |  29 +--
 arch/x86/pci/Makefile                         |   2 -
 arch/x86/pci/sta2x11-fixup.c                  | 233 ------------------
 include/linux/mm.h                            |   2 +-
 55 files changed, 185 insertions(+), 1216 deletions(-)
 delete mode 100644 arch/x86/include/asm/sta2x11.h
 delete mode 100644 arch/x86/kernel/apic/bigsmp_32.c
 delete mode 100644 arch/x86/pci/sta2x11-fixup.c