Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
to use the generic entry infrastructure from kernel/entry/*. The generic
entry makes maintainers' work easier and codes more elegant, which aslo
removed a lot of duplicate code.

The main steps are as follows:
- Make arm64 easier to use irqentry_enter/exit().
- Make arm64 closer to the PREEMPT_DYNAMIC code of generic entry.
- Split generic entry into generic irq entry and generic syscall to
  make the single patch more concentrated in switching to one thing.
- Switch to generic irq entry.
- Make arm64 closer to the generic syscall code.
- Switch to generic entry completely.

Changes in v5:
- Not change arm32 and keep inerrupts_enabled() macro for gicv3 driver.
- Move irqentry_state definition into arch/arm64/kernel/entry-common.c.
- Avoid removing the __enter_from_*() and __exit_to_*() wrappers.
- Update "irqentry_state_t ret/irq_state" to "state"
  to keep it consistently.
- Use generic irq entry header for PREEMPT_DYNAMIC after split
  the generic entry.
- Also refactor the ARM64 syscall code.
- Introduce arch_ptrace_report_syscall_entry/exit(), instead of
  arch_pre/post_report_syscall_entry/exit() to simplify code.
- Make the syscall patches clear separation.
- Update the commit message.

Changes in v4:
- Rework/cleanup split into a few patches as Mark suggested.
- Replace interrupts_enabled() macro with regs_irqs_disabled(), instead
  of left it here.
- Remove rcu and lockdep state in pt_regs by using temporary
  irqentry_state_t as Mark suggested.
- Remove some unnecessary intermediate functions to make it clear.
- Rework preempt irq and PREEMPT_DYNAMIC code
  to make the switch more clear.
- arch_prepare_*_entry/exit() -> arch_pre_*_entry/exit().
- Expand the arch functions comment.
- Make arch functions closer to its caller.
- Declare saved_reg in for block.
- Remove arch_exit_to_kernel_mode_prepare(), arch_enter_from_kernel_mode().
- Adjust "Add few arch functions to use generic entry" patch to be
  the penultimate.
- Update the commit message.
- Add suggested-by.

Changes in v3:
- Test the MTE test cases.
- Handle forget_syscall() in arch_post_report_syscall_entry()
- Make the arch funcs not use __weak as Thomas suggested, so move
  the arch funcs to entry-common.h, and make arch_forget_syscall() folded
  in arch_post_report_syscall_entry() as suggested.
- Move report_single_step() to thread_info.h for arm64
- Change __always_inline() to inline, add inline for the other arch funcs.
- Remove unused signal.h for entry-common.h.
- Add Suggested-by.
- Update the commit message.

Changes in v2:
- Add tested-by.
- Fix a bug that not call arch_post_report_syscall_entry() in
  syscall_trace_enter() if ptrace_report_syscall_entry() return not zero.
- Refactor report_syscall().
- Add comment for arch_prepare_report_syscall_exit().
- Adjust entry-common.h header file inclusion to alphabetical order.
- Update the commit message.

Jinjie Ruan (22):
  arm64: ptrace: Replace interrupts_enabled() with regs_irqs_disabled()
  arm64: entry: Refactor the entry and exit for exceptions from EL1
  arm64: entry: Move arm64_preempt_schedule_irq() into
    __exit_to_kernel_mode()
  arm64: entry: Rework arm64_preempt_schedule_irq()
  arm64: entry: Use preempt_count() and need_resched() helper
  arm64: entry: Expand the need_irq_preemption() macro ahead
  arm64: entry: preempt_schedule_irq() only if PREEMPTION enabled
  arm64: entry: Use different helpers to check resched for
    PREEMPT_DYNAMIC
  entry: Split generic entry into irq and syscall
  entry: Add arch_irqentry_exit_need_resched() for arm64
  arm64: entry: Switch to generic IRQ entry
  arm64/ptrace: Split report_syscall() function
  arm64/ptrace: Refactor syscall_trace_enter()
  arm64/ptrace: Refactor syscall_trace_exit()
  arm64/ptrace: Refator el0_svc_common()
  entry: Make syscall_exit_to_user_mode_prepare() not static
  arm64/ptrace: Return early for ptrace_report_syscall_entry() error
  arm64/ptrace: Expand secure_computing() in place
  arm64/ptrace: Use syscall_get_arguments() heleper
  entry: Add arch_ptrace_report_syscall_entry/exit()
  entry: Add has_syscall_work() helepr
  arm64: entry: Convert to generic entry

 MAINTAINERS                           |   1 +
 arch/Kconfig                          |   8 +
 arch/arm64/Kconfig                    |   1 +
 arch/arm64/include/asm/daifflags.h    |   2 +-
 arch/arm64/include/asm/entry-common.h | 134 +++++++++
 arch/arm64/include/asm/preempt.h      |   2 -
 arch/arm64/include/asm/ptrace.h       |  11 +-
 arch/arm64/include/asm/syscall.h      |   6 +-
 arch/arm64/include/asm/thread_info.h  |  23 +-
 arch/arm64/include/asm/xen/events.h   |   2 +-
 arch/arm64/kernel/acpi.c              |   2 +-
 arch/arm64/kernel/debug-monitors.c    |   9 +-
 arch/arm64/kernel/entry-common.c      | 377 ++++++++-----------------
 arch/arm64/kernel/ptrace.c            |  90 ------
 arch/arm64/kernel/sdei.c              |   2 +-
 arch/arm64/kernel/signal.c            |   3 +-
 arch/arm64/kernel/syscall.c           |  31 +-
 include/linux/entry-common.h          | 384 +------------------------
 include/linux/irq-entry-common.h      | 389 ++++++++++++++++++++++++++
 kernel/entry/Makefile                 |   3 +-
 kernel/entry/common.c                 | 176 ++----------
 kernel/entry/syscall-common.c         | 198 +++++++++++++
 kernel/sched/core.c                   |   8 +-
 23 files changed, 909 insertions(+), 953 deletions(-)
 create mode 100644 arch/arm64/include/asm/entry-common.h
 create mode 100644 include/linux/irq-entry-common.h
 create mode 100644 kernel/entry/syscall-common.c

-- 
2.34.1

On 2024/12/6 18:17, Jinjie Ruan wrote:
> Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
> to use the generic entry infrastructure from kernel/entry/*. The generic
> entry makes maintainers' work easier and codes more elegant, which aslo
> removed a lot of duplicate code.
> 
> The main steps are as follows:
> - Make arm64 easier to use irqentry_enter/exit().
> - Make arm64 closer to the PREEMPT_DYNAMIC code of generic entry.
> - Split generic entry into generic irq entry and generic syscall to
>   make the single patch more concentrated in switching to one thing.
> - Switch to generic irq entry.
> - Make arm64 closer to the generic syscall code.
> - Switch to generic entry completely.
> 
> Changes in v5:
> - Not change arm32 and keep inerrupts_enabled() macro for gicv3 driver.
> - Move irqentry_state definition into arch/arm64/kernel/entry-common.c.
> - Avoid removing the __enter_from_*() and __exit_to_*() wrappers.
> - Update "irqentry_state_t ret/irq_state" to "state"
>   to keep it consistently.
> - Use generic irq entry header for PREEMPT_DYNAMIC after split
>   the generic entry.
> - Also refactor the ARM64 syscall code.
> - Introduce arch_ptrace_report_syscall_entry/exit(), instead of
>   arch_pre/post_report_syscall_entry/exit() to simplify code.
> - Make the syscall patches clear separation.
> - Update the commit message.

Gentle Ping.

> 
> Changes in v4:
> - Rework/cleanup split into a few patches as Mark suggested.
> - Replace interrupts_enabled() macro with regs_irqs_disabled(), instead
>   of left it here.
> - Remove rcu and lockdep state in pt_regs by using temporary
>   irqentry_state_t as Mark suggested.
> - Remove some unnecessary intermediate functions to make it clear.
> - Rework preempt irq and PREEMPT_DYNAMIC code
>   to make the switch more clear.
> - arch_prepare_*_entry/exit() -> arch_pre_*_entry/exit().
> - Expand the arch functions comment.
> - Make arch functions closer to its caller.
> - Declare saved_reg in for block.
> - Remove arch_exit_to_kernel_mode_prepare(), arch_enter_from_kernel_mode().
> - Adjust "Add few arch functions to use generic entry" patch to be
>   the penultimate.
> - Update the commit message.
> - Add suggested-by.
> 
> Changes in v3:
> - Test the MTE test cases.
> - Handle forget_syscall() in arch_post_report_syscall_entry()
> - Make the arch funcs not use __weak as Thomas suggested, so move
>   the arch funcs to entry-common.h, and make arch_forget_syscall() folded
>   in arch_post_report_syscall_entry() as suggested.
> - Move report_single_step() to thread_info.h for arm64
> - Change __always_inline() to inline, add inline for the other arch funcs.
> - Remove unused signal.h for entry-common.h.
> - Add Suggested-by.
> - Update the commit message.
> 
> Changes in v2:
> - Add tested-by.
> - Fix a bug that not call arch_post_report_syscall_entry() in
>   syscall_trace_enter() if ptrace_report_syscall_entry() return not zero.
> - Refactor report_syscall().
> - Add comment for arch_prepare_report_syscall_exit().
> - Adjust entry-common.h header file inclusion to alphabetical order.
> - Update the commit message.
> 
> Jinjie Ruan (22):
>   arm64: ptrace: Replace interrupts_enabled() with regs_irqs_disabled()
>   arm64: entry: Refactor the entry and exit for exceptions from EL1
>   arm64: entry: Move arm64_preempt_schedule_irq() into
>     __exit_to_kernel_mode()
>   arm64: entry: Rework arm64_preempt_schedule_irq()
>   arm64: entry: Use preempt_count() and need_resched() helper
>   arm64: entry: Expand the need_irq_preemption() macro ahead
>   arm64: entry: preempt_schedule_irq() only if PREEMPTION enabled
>   arm64: entry: Use different helpers to check resched for
>     PREEMPT_DYNAMIC
>   entry: Split generic entry into irq and syscall
>   entry: Add arch_irqentry_exit_need_resched() for arm64
>   arm64: entry: Switch to generic IRQ entry
>   arm64/ptrace: Split report_syscall() function
>   arm64/ptrace: Refactor syscall_trace_enter()
>   arm64/ptrace: Refactor syscall_trace_exit()
>   arm64/ptrace: Refator el0_svc_common()
>   entry: Make syscall_exit_to_user_mode_prepare() not static
>   arm64/ptrace: Return early for ptrace_report_syscall_entry() error
>   arm64/ptrace: Expand secure_computing() in place
>   arm64/ptrace: Use syscall_get_arguments() heleper
>   entry: Add arch_ptrace_report_syscall_entry/exit()
>   entry: Add has_syscall_work() helepr
>   arm64: entry: Convert to generic entry
> 
>  MAINTAINERS                           |   1 +
>  arch/Kconfig                          |   8 +
>  arch/arm64/Kconfig                    |   1 +
>  arch/arm64/include/asm/daifflags.h    |   2 +-
>  arch/arm64/include/asm/entry-common.h | 134 +++++++++
>  arch/arm64/include/asm/preempt.h      |   2 -
>  arch/arm64/include/asm/ptrace.h       |  11 +-
>  arch/arm64/include/asm/syscall.h      |   6 +-
>  arch/arm64/include/asm/thread_info.h  |  23 +-
>  arch/arm64/include/asm/xen/events.h   |   2 +-
>  arch/arm64/kernel/acpi.c              |   2 +-
>  arch/arm64/kernel/debug-monitors.c    |   9 +-
>  arch/arm64/kernel/entry-common.c      | 377 ++++++++-----------------
>  arch/arm64/kernel/ptrace.c            |  90 ------
>  arch/arm64/kernel/sdei.c              |   2 +-
>  arch/arm64/kernel/signal.c            |   3 +-
>  arch/arm64/kernel/syscall.c           |  31 +-
>  include/linux/entry-common.h          | 384 +------------------------
>  include/linux/irq-entry-common.h      | 389 ++++++++++++++++++++++++++
>  kernel/entry/Makefile                 |   3 +-
>  kernel/entry/common.c                 | 176 ++----------
>  kernel/entry/syscall-common.c         | 198 +++++++++++++
>  kernel/sched/core.c                   |   8 +-
>  23 files changed, 909 insertions(+), 953 deletions(-)
>  create mode 100644 arch/arm64/include/asm/entry-common.h
>  create mode 100644 include/linux/irq-entry-common.h
>  create mode 100644 kernel/entry/syscall-common.c
>

On Sat, Feb 08, 2025 at 09:15:08AM +0800, Jinjie Ruan wrote:
> On 2024/12/6 18:17, Jinjie Ruan wrote:
> > Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
> > to use the generic entry infrastructure from kernel/entry/*. The generic
> > entry makes maintainers' work easier and codes more elegant, which aslo
> > removed a lot of duplicate code.
> > 
> > The main steps are as follows:
> > - Make arm64 easier to use irqentry_enter/exit().
> > - Make arm64 closer to the PREEMPT_DYNAMIC code of generic entry.
> > - Split generic entry into generic irq entry and generic syscall to
> >   make the single patch more concentrated in switching to one thing.
> > - Switch to generic irq entry.
> > - Make arm64 closer to the generic syscall code.
> > - Switch to generic entry completely.
> > 
> > Changes in v5:
> > - Not change arm32 and keep inerrupts_enabled() macro for gicv3 driver.
> > - Move irqentry_state definition into arch/arm64/kernel/entry-common.c.
> > - Avoid removing the __enter_from_*() and __exit_to_*() wrappers.
> > - Update "irqentry_state_t ret/irq_state" to "state"
> >   to keep it consistently.
> > - Use generic irq entry header for PREEMPT_DYNAMIC after split
> >   the generic entry.
> > - Also refactor the ARM64 syscall code.
> > - Introduce arch_ptrace_report_syscall_entry/exit(), instead of
> >   arch_pre/post_report_syscall_entry/exit() to simplify code.
> > - Make the syscall patches clear separation.
> > - Update the commit message.
> 
> Gentle Ping.

I've left soem comments.

As I mentioned previously, I'd very much prefer that we do the syscall
entry logic changes *later* (i.e. as a follow-up patch series), after
we've got the irq/exception entry logic sorted.

I reckon we've got just enough time to get the irq/exception entry
changes ready this cycle, with another round or two of review. So can we
please put the syscall bits aside for now? ... that and run all the
tests you mention in patch 22 on the irq/exception entry changes alone.

Mark.

On 2025/2/10 20:30, Mark Rutland wrote:
> On Sat, Feb 08, 2025 at 09:15:08AM +0800, Jinjie Ruan wrote:
>> On 2024/12/6 18:17, Jinjie Ruan wrote:
>>> Currently, x86, Riscv, Loongarch use the generic entry. Convert arm64
>>> to use the generic entry infrastructure from kernel/entry/*. The generic
>>> entry makes maintainers' work easier and codes more elegant, which aslo
>>> removed a lot of duplicate code.
>>>
>>> The main steps are as follows:
>>> - Make arm64 easier to use irqentry_enter/exit().
>>> - Make arm64 closer to the PREEMPT_DYNAMIC code of generic entry.
>>> - Split generic entry into generic irq entry and generic syscall to
>>>   make the single patch more concentrated in switching to one thing.
>>> - Switch to generic irq entry.
>>> - Make arm64 closer to the generic syscall code.
>>> - Switch to generic entry completely.
>>>
>>> Changes in v5:
>>> - Not change arm32 and keep inerrupts_enabled() macro for gicv3 driver.
>>> - Move irqentry_state definition into arch/arm64/kernel/entry-common.c.
>>> - Avoid removing the __enter_from_*() and __exit_to_*() wrappers.
>>> - Update "irqentry_state_t ret/irq_state" to "state"
>>>   to keep it consistently.
>>> - Use generic irq entry header for PREEMPT_DYNAMIC after split
>>>   the generic entry.
>>> - Also refactor the ARM64 syscall code.
>>> - Introduce arch_ptrace_report_syscall_entry/exit(), instead of
>>>   arch_pre/post_report_syscall_entry/exit() to simplify code.
>>> - Make the syscall patches clear separation.
>>> - Update the commit message.
>>
>> Gentle Ping.
> 
> I've left soem comments.
> 
> As I mentioned previously, I'd very much prefer that we do the syscall
> entry logic changes *later* (i.e. as a follow-up patch series), after
> we've got the irq/exception entry logic sorted.
> 
> I reckon we've got just enough time to get the irq/exception entry
> changes ready this cycle, with another round or two of review. So can we
> please put the syscall bits aside for now? ... that and run all the
> tests you mention in patch 22 on the irq/exception entry changes alone.

Sure, it is ok to put the syscall bits aside and split it out .

> 
> Mark.
> 
>