[PATCH v2 00/11] x86: 32-bit cleanups

Arnd Bergmann posted 11 patches 1 year ago
There is a newer version of this series
Documentation/admin-guide/kdump/kdump.rst     |   4 -
.../admin-guide/kernel-parameters.txt         |  11 -
Documentation/arch/x86/usb-legacy-support.rst |  11 +-
arch/x86/Kconfig                              | 460 +-----------------
arch/x86/Kconfig.cpu                          | 111 ++---
arch/x86/Kconfig.platforms                    | 361 ++++++++++++++
arch/x86/Makefile                             |  21 +-
arch/x86/Makefile_32.cpu                      |   5 +-
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/mm/init_32.c                         |   9 +-
arch/x86/mm/pgtable.c                         |  32 +-
arch/x86/pci/Makefile                         |   2 -
arch/x86/pci/sta2x11-fixup.c                  | 233 ---------
drivers/misc/mei/Kconfig                      |   2 +-
include/linux/mm.h                            |   2 +-
24 files changed, 422 insertions(+), 1023 deletions(-)
create mode 100644 arch/x86/Kconfig.platforms
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
[PATCH v2 00/11] x86: 32-bit cleanups
Posted by Arnd Bergmann 1 year ago
From: Arnd Bergmann <arnd@arndb.de>

[sorry for sending a duplicate series, I just noticed I had
 dropped lkml from cc when I sent this a few minutes ago]

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.

Changes since v1:

 - Don't include patch to drop 32-bit KVM support for now
 - Drop patch for 64-bit Silverlake support
 - Drop 64-bit ISA level selection, only fix default
 - Rework MID patch based on comments
 - Add a patch to reorganize platform selection
 - Add a patch to add -march=native compilation

Arnd Bergmann (11):
  x86/Kconfig: Geode CPU has cmpxchg8b
  x86: drop 32-bit "bigsmp" machine support
  x86: rework CONFIG_GENERIC_CPU compiler flags
  x86: drop configuration options for early 64-bit CPUs
  x86: add CONFIG_X86_64_NATIVE option
  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: remove old STA2x11 support
  x86: Move platforms to Kconfig.platforms

 Documentation/admin-guide/kdump/kdump.rst     |   4 -
 .../admin-guide/kernel-parameters.txt         |  11 -
 Documentation/arch/x86/usb-legacy-support.rst |  11 +-
 arch/x86/Kconfig                              | 460 +-----------------
 arch/x86/Kconfig.cpu                          | 111 ++---
 arch/x86/Kconfig.platforms                    | 361 ++++++++++++++
 arch/x86/Makefile                             |  21 +-
 arch/x86/Makefile_32.cpu                      |   5 +-
 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/mm/init_32.c                         |   9 +-
 arch/x86/mm/pgtable.c                         |  32 +-
 arch/x86/pci/Makefile                         |   2 -
 arch/x86/pci/sta2x11-fixup.c                  | 233 ---------
 drivers/misc/mei/Kconfig                      |   2 +-
 include/linux/mm.h                            |   2 +-
 24 files changed, 422 insertions(+), 1023 deletions(-)
 create mode 100644 arch/x86/Kconfig.platforms
 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

-- 
2.39.5

To: x86@kernel.org 
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Re: [PATCH v2 00/11] x86: 32-bit cleanups
Posted by Andy Shevchenko 1 year ago
On Tue, Dec 10, 2024 at 4:49 PM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> [sorry for sending a duplicate series, I just noticed I had
>  dropped lkml from cc when I sent this a few minutes ago]
>
> 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

Similarly

> 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.

...

>   x86: document X86_INTEL_MID as 64-bit-only

Acked-by: Andy Shevchenko <andy@kernel.org>

-- 
With Best Regards,
Andy Shevchenko