[PATCH v3 7/8] powerpc: Enable IRQ generic entry/exit path.

[Mukesh Kumar Chaurasiya]

On Thu, Jan 01, 2026 at 11:01:08PM +0530, Shrikanth Hegde wrote:
> 
> 
> On 12/29/25 10:24 AM, Mukesh Kumar Chaurasiya wrote:
> > From: Mukesh Kumar Chaurasiya <mchauras at linux.ibm.com>
> > 
> > Enable the generic IRQ entry/exit infrastructure on PowerPC by selecting
> > GENERIC_IRQ_ENTRY and integrating the architecture-specific interrupt
> > handlers with the generic entry/exit APIs.
> > 
> > This change replaces PowerPC’s local interrupt entry/exit handling with
> > calls to the generic irqentry_* helpers, aligning the architecture with
> > the common kernel entry model. The macros that define interrupt, async,
> > and NMI handlers are updated to use irqentry_enter()/irqentry_exit()
> > and irqentry_nmi_enter()/irqentry_nmi_exit() where applicable.
> > 
> > Key updates include:
> >   - Select GENERIC_IRQ_ENTRY in Kconfig.
> >   - Replace interrupt_enter/exit_prepare() with arch_interrupt_* helpers.
> >   - Integrate irqentry_enter()/exit() in standard and async interrupt paths.
> >   - Integrate irqentry_nmi_enter()/exit() in NMI handlers.
> >   - Remove redundant irq_enter()/irq_exit() calls now handled generically.
> >   - Use irqentry_exit_cond_resched() for preemption checks.
> >   - Remove unused code.
> > 
> > This change establishes the necessary wiring for PowerPC to use the
> > generic IRQ entry/exit framework while maintaining existing semantics.
> > 
> > Signed-off-by: Mukesh Kumar Chaurasiya <mchauras at linux.ibm.com>
> > ---
> >   arch/powerpc/Kconfig                    |   1 +
> >   arch/powerpc/include/asm/entry-common.h |  61 +--
> >   arch/powerpc/include/asm/interrupt.h    | 484 +++---------------------
> >   arch/powerpc/kernel/interrupt.c         |  15 +-
> >   4 files changed, 72 insertions(+), 489 deletions(-)
> > 
> > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> > index 9537a61ebae0..398cef868c14 100644
> > --- a/arch/powerpc/Kconfig
> > +++ b/arch/powerpc/Kconfig
> > @@ -207,6 +207,7 @@ config PPC
> >   	select GENERIC_GETTIMEOFDAY
> >   	select GENERIC_IDLE_POLL_SETUP
> >   	select GENERIC_IOREMAP
> > +	select GENERIC_IRQ_ENTRY
> >   	select GENERIC_IRQ_SHOW
> >   	select GENERIC_IRQ_SHOW_LEVEL
> >   	select GENERIC_PCI_IOMAP		if PCI
> 
> There is no need for GENERIC_IRQ_ENTRY. I don't see a reason why
> we need to have both.
> 
> Enabling GENERIC_ENTRY which is done in next patch will enable this.
> It does the same thing and one less kconfig to worry about.
> 
> This would allow some easier code refactoring IMO.
> 
> - You can keep adding code to asm/entry-common.h. This will help avoid
>   moving to interrupt.h in between.
> 
Yeah this would be good, will send out in next revision.
> - You can add another patch as cleanup post GENERIC_ENTRY for
> easier review for seccomp/ptrace.
> 
Sure.
> ...
> 
> - Some more ct_warning in arch/powerpc are probably not necessary
>   (can be done post the series too)
> 
> - Some more cleanups can be done w.r.t to lockdep and tracing hardirq etc.
>   For example in next_interrupt. I think replay soft interrupts will end
>   up making irqentry_enter/exit calls which does same or similar thing.
>   (can be done post the series too)
> 
> - can we move syscall_exit_prepare/ into kernel/syscall.c?
>   (can be done post the series too)

Sure will do all of above in a separate series.

Regards,
Mukesh