mbox series

[GIT,PULL] Generic entry for ARM

Message ID CACRpkdZCiiMTwf7eGJJ9aCKFOC3_xTGv1JKQUijjyp+_++cZ_A@mail.gmail.com (mailing list archive)
State New, archived
Headers show
Series [GIT,PULL] Generic entry for ARM | expand

Pull-request

git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git tags/arm-generic-entry-for-v6.15

Message

Linus Walleij Feb. 28, 2025, 12:49 p.m. UTC 
Hi Russell,

please consider pulling the following git branch for generic entry,
see below.

This branch was just harvested from my own v5 patch series on
lore with b4 am -t 20250225-arm-generic-entry-v5-0-2f02313653e5@linaro.org
then git am on top of v6.14-rc1, so you can do the same if you
prefer.

It's possible to squash patches, even all of them into one
big all-or-nothing patch, given the not very gradual nature generic
entry conversion seems to have.

Main upsides and downsides are in the signed tag.

I don't know who the most important stakeholders are, but I guess
the context tracker maintainer (Paul McKenney) and the people working
on generic entry (tglx) could have a say on how important this is, or isn't.

I think it's pretty neat.

Yours,
Linus Walleij

The following changes since commit 2014c95afecee3e76ca4a56956a936e23283f05b:

  Linux 6.14-rc1 (2025-02-02 15:39:26 -0800)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git
tags/arm-generic-entry-for-v6.15

for you to fetch changes up to 98b8e133458a3feefdf882ea16fb7f1f576a49e5:

  ARM: entry: Reimplement local restart in C (2025-02-28 13:40:44 +0100)

----------------------------------------------------------------
Main upsides:

- Using the same common entry as used by x86_64, RISCV, S390
  and Loongarch, probably soon also ARM64.

- Moves ARM away from the obsoleted context tracker entry points
  user_enter_callable() and user_exit_callable() are now only used
  by ARM, CSKY and Xtensa.

- Solves a few lockdep warnings in the process.

- Converts a bit of assembly into C.

Main downside:

- Slightly increased system call overhead, around 6% in
  measurements.

----------------------------------------------------------------
Linus Walleij (31):
      ARM: Prepare includes for generic entry
      ARM: ptrace: Split report_syscall()
      ARM: entry: Skip ret_slow_syscall label
      ARM: process: Rewrite ret_from_fork i C
      ARM: process: Remove local restart
      ARM: entry: Invoke syscalls using C
      ARM: entry: Rewrite two asm calls in C
      ARM: entry: Move trace entry to C function
      ARM: entry: save the syscall sp in thread_info
      ARM: entry: move all tracing invocation to C
      ARM: entry: Merge the common and trace entry code
      ARM: entry: Rename syscall invocation
      ARM: entry: Create user_mode_enter/exit
      ARM: entry: Drop trace argument from usr_entry macro
      ARM: entry: Separate call path for syscall SWI entry
      ARM: entry: Drop argument to asm_irqentry macros
      ARM: entry: Implement syscall_exit_to_user_mode()
      ARM: entry: Drop the superfast ret_fast_syscall
      ARM: entry: Remove fast and offset register restore
      ARM: entry: Untangle ret_fast_syscall/to_user
      ARM: entry: Do not double-call exit functions
      ARM: entry: Move work processing to C
      ARM: entry: Stop exiting syscalls like IRQs
      ARM: entry: Complete syscall and IRQ transition to C
      ARM: entry: Create irqentry calls from kernel mode
      ARM: entry: Move in-kernel hardirq tracing to C
      ARM: irq: Add irqstack helper
      ARM: entry: Convert to generic entry
      ARM: entry: Handle dabt, pabt, and und as interrupts
      ARM: entry: Block IRQs in early IRQ context
      ARM: entry: Reimplement local restart in C

 arch/arm/Kconfig                    |   1 +
 arch/arm/include/asm/entry-common.h |  66 ++++++++++++
 arch/arm/include/asm/entry.h        |  14 +++
 arch/arm/include/asm/ptrace.h       |   8 +-
 arch/arm/include/asm/signal.h       |   4 -
 arch/arm/include/asm/stacktrace.h   |   2 +-
 arch/arm/include/asm/switch_to.h    |   4 +
 arch/arm/include/asm/syscall.h      |   7 ++
 arch/arm/include/asm/thread_info.h  |  22 ++--
 arch/arm/include/asm/traps.h        |   5 +-
 arch/arm/include/uapi/asm/ptrace.h  |   2 +
 arch/arm/kernel/Makefile            |   5 +-
 arch/arm/kernel/asm-offsets.c       |   1 +
 arch/arm/kernel/entry-armv.S        |  82 ++++-----------
 arch/arm/kernel/entry-common.S      | 198 +++++++++++++-----------------------
 arch/arm/kernel/entry-header.S      | 100 ++----------------
 arch/arm/kernel/entry.c             | 120 ++++++++++++++++++++++
 arch/arm/kernel/irq.c               |   6 ++
 arch/arm/kernel/irq.h               |   2 +
 arch/arm/kernel/process.c           |  25 ++++-
 arch/arm/kernel/ptrace.c            |  81 +--------------
 arch/arm/kernel/signal.c            |  68 +++----------
 arch/arm/kernel/syscall.c           |  59 +++++++++++
 arch/arm/kernel/traps.c             |  30 +-----
 arch/arm/mm/abort-ev4.S             |   2 +-
 arch/arm/mm/abort-ev4t.S            |   2 +-
 arch/arm/mm/abort-ev5t.S            |   4 +-
 arch/arm/mm/abort-ev5tj.S           |   6 +-
 arch/arm/mm/abort-ev6.S             |   2 +-
 arch/arm/mm/abort-ev7.S             |   2 +-
 arch/arm/mm/abort-lv4t.S            |  36 +++----
 arch/arm/mm/abort-macro.S           |   2 +-
 arch/arm/mm/abort-nommu.S           |   2 +-
 arch/arm/mm/fault.c                 |   4 +-
 arch/arm/mm/fault.h                 |   8 +-
 arch/arm/mm/pabort-legacy.S         |   2 +-
 arch/arm/mm/pabort-v6.S             |   2 +-
 arch/arm/mm/pabort-v7.S             |   2 +-
 38 files changed, 484 insertions(+), 504 deletions(-)
 create mode 100644 arch/arm/include/asm/entry-common.h
 create mode 100644 arch/arm/include/asm/entry.h
 create mode 100644 arch/arm/kernel/entry.c
 create mode 100644 arch/arm/kernel/irq.h
 create mode 100644 arch/arm/kernel/syscall.c

Comments

Thomas Gleixner March 12, 2025, 11:13 a.m. UTC | #1 
On Fri, Feb 28 2025 at 13:49, Linus Walleij wrote:
> please consider pulling the following git branch for generic entry,
> see below.
>
> This branch was just harvested from my own v5 patch series on
> lore with b4 am -t 20250225-arm-generic-entry-v5-0-2f02313653e5@linaro.org
> then git am on top of v6.14-rc1, so you can do the same if you
> prefer.
>
> It's possible to squash patches, even all of them into one
> big all-or-nothing patch, given the not very gradual nature generic
> entry conversion seems to have.
>
> Main upsides and downsides are in the signed tag.
>
> I don't know who the most important stakeholders are, but I guess
> the context tracker maintainer (Paul McKenney) and the people working
> on generic entry (tglx) could have a say on how important this is, or isn't.
>
> I think it's pretty neat.

It's valuable to consolidate these common functionalities across
architectures as it reduces maintainence costs.

I read through the patches and did not find anything offending there.

Thanks for doing that!

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Paul E. McKenney March 12, 2025, 6 p.m. UTC | #2 
On Fri, Feb 28, 2025 at 01:49:36PM +0100, Linus Walleij wrote:
> Hi Russell,
> 
> please consider pulling the following git branch for generic entry,
> see below.
> 
> This branch was just harvested from my own v5 patch series on
> lore with b4 am -t 20250225-arm-generic-entry-v5-0-2f02313653e5@linaro.org
> then git am on top of v6.14-rc1, so you can do the same if you
> prefer.
> 
> It's possible to squash patches, even all of them into one
> big all-or-nothing patch, given the not very gradual nature generic
> entry conversion seems to have.
> 
> Main upsides and downsides are in the signed tag.
> 
> I don't know who the most important stakeholders are, but I guess
> the context tracker maintainer (Paul McKenney) and the people working
> on generic entry (tglx) could have a say on how important this is, or isn't.
> 
> I think it's pretty neat.

No argument here!

Once you are confident that you have all the needed "noinstr"
and "__always_inline" instances in place, could you please add
ARCH_WANTS_NO_INSTR to the list of "select" clauses for "config ARM"
in arch/arm/Kconfig?

Once all architectures that support trampoline-based tracing also select
ARCH_WANTS_NO_INSTR we can drop RCU Tasks Rude.  ;-)

In the meantime, for the series:

Acked-by: Paul E. McKenney <paulmck@kernel.org>

							Thanx, Paul

> Yours,
> Linus Walleij
> 
> The following changes since commit 2014c95afecee3e76ca4a56956a936e23283f05b:
> 
>   Linux 6.14-rc1 (2025-02-02 15:39:26 -0800)
> 
> are available in the Git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git
> tags/arm-generic-entry-for-v6.15
> 
> for you to fetch changes up to 98b8e133458a3feefdf882ea16fb7f1f576a49e5:
> 
>   ARM: entry: Reimplement local restart in C (2025-02-28 13:40:44 +0100)
> 
> ----------------------------------------------------------------
> Main upsides:
> 
> - Using the same common entry as used by x86_64, RISCV, S390
>   and Loongarch, probably soon also ARM64.
> 
> - Moves ARM away from the obsoleted context tracker entry points
>   user_enter_callable() and user_exit_callable() are now only used
>   by ARM, CSKY and Xtensa.
> 
> - Solves a few lockdep warnings in the process.
> 
> - Converts a bit of assembly into C.
> 
> Main downside:
> 
> - Slightly increased system call overhead, around 6% in
>   measurements.
> 
> ----------------------------------------------------------------
> Linus Walleij (31):
>       ARM: Prepare includes for generic entry
>       ARM: ptrace: Split report_syscall()
>       ARM: entry: Skip ret_slow_syscall label
>       ARM: process: Rewrite ret_from_fork i C
>       ARM: process: Remove local restart
>       ARM: entry: Invoke syscalls using C
>       ARM: entry: Rewrite two asm calls in C
>       ARM: entry: Move trace entry to C function
>       ARM: entry: save the syscall sp in thread_info
>       ARM: entry: move all tracing invocation to C
>       ARM: entry: Merge the common and trace entry code
>       ARM: entry: Rename syscall invocation
>       ARM: entry: Create user_mode_enter/exit
>       ARM: entry: Drop trace argument from usr_entry macro
>       ARM: entry: Separate call path for syscall SWI entry
>       ARM: entry: Drop argument to asm_irqentry macros
>       ARM: entry: Implement syscall_exit_to_user_mode()
>       ARM: entry: Drop the superfast ret_fast_syscall
>       ARM: entry: Remove fast and offset register restore
>       ARM: entry: Untangle ret_fast_syscall/to_user
>       ARM: entry: Do not double-call exit functions
>       ARM: entry: Move work processing to C
>       ARM: entry: Stop exiting syscalls like IRQs
>       ARM: entry: Complete syscall and IRQ transition to C
>       ARM: entry: Create irqentry calls from kernel mode
>       ARM: entry: Move in-kernel hardirq tracing to C
>       ARM: irq: Add irqstack helper
>       ARM: entry: Convert to generic entry
>       ARM: entry: Handle dabt, pabt, and und as interrupts
>       ARM: entry: Block IRQs in early IRQ context
>       ARM: entry: Reimplement local restart in C
> 
>  arch/arm/Kconfig                    |   1 +
>  arch/arm/include/asm/entry-common.h |  66 ++++++++++++
>  arch/arm/include/asm/entry.h        |  14 +++
>  arch/arm/include/asm/ptrace.h       |   8 +-
>  arch/arm/include/asm/signal.h       |   4 -
>  arch/arm/include/asm/stacktrace.h   |   2 +-
>  arch/arm/include/asm/switch_to.h    |   4 +
>  arch/arm/include/asm/syscall.h      |   7 ++
>  arch/arm/include/asm/thread_info.h  |  22 ++--
>  arch/arm/include/asm/traps.h        |   5 +-
>  arch/arm/include/uapi/asm/ptrace.h  |   2 +
>  arch/arm/kernel/Makefile            |   5 +-
>  arch/arm/kernel/asm-offsets.c       |   1 +
>  arch/arm/kernel/entry-armv.S        |  82 ++++-----------
>  arch/arm/kernel/entry-common.S      | 198 +++++++++++++-----------------------
>  arch/arm/kernel/entry-header.S      | 100 ++----------------
>  arch/arm/kernel/entry.c             | 120 ++++++++++++++++++++++
>  arch/arm/kernel/irq.c               |   6 ++
>  arch/arm/kernel/irq.h               |   2 +
>  arch/arm/kernel/process.c           |  25 ++++-
>  arch/arm/kernel/ptrace.c            |  81 +--------------
>  arch/arm/kernel/signal.c            |  68 +++----------
>  arch/arm/kernel/syscall.c           |  59 +++++++++++
>  arch/arm/kernel/traps.c             |  30 +-----
>  arch/arm/mm/abort-ev4.S             |   2 +-
>  arch/arm/mm/abort-ev4t.S            |   2 +-
>  arch/arm/mm/abort-ev5t.S            |   4 +-
>  arch/arm/mm/abort-ev5tj.S           |   6 +-
>  arch/arm/mm/abort-ev6.S             |   2 +-
>  arch/arm/mm/abort-ev7.S             |   2 +-
>  arch/arm/mm/abort-lv4t.S            |  36 +++----
>  arch/arm/mm/abort-macro.S           |   2 +-
>  arch/arm/mm/abort-nommu.S           |   2 +-
>  arch/arm/mm/fault.c                 |   4 +-
>  arch/arm/mm/fault.h                 |   8 +-
>  arch/arm/mm/pabort-legacy.S         |   2 +-
>  arch/arm/mm/pabort-v6.S             |   2 +-
>  arch/arm/mm/pabort-v7.S             |   2 +-
>  38 files changed, 484 insertions(+), 504 deletions(-)
>  create mode 100644 arch/arm/include/asm/entry-common.h
>  create mode 100644 arch/arm/include/asm/entry.h
>  create mode 100644 arch/arm/kernel/entry.c
>  create mode 100644 arch/arm/kernel/irq.h
>  create mode 100644 arch/arm/kernel/syscall.c