From: Nicholas Piggin <npiggin@gmail.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Michael Ellerman <mpe@ellerman.id.au>,
Paul Mackerras <paulus@samba.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 1/4] powerpc/interrupt: Interchange prep_irq_for_{kernel_enabled/user}_exit()
Date: Fri, 11 Jun 2021 12:26:44 +1000 [thread overview]
Message-ID: <1623378363.09q00gd3lj.astroid@bobo.none> (raw)
In-Reply-To: <809d316bf5f1a81acdd69e220c13e716dac24f53.1622818556.git.christophe.leroy@csgroup.eu>
Excerpts from Christophe Leroy's message of June 5, 2021 12:56 am:
> prep_irq_for_user_exit() is a superset of
> prep_irq_for_kernel_enabled_exit(). In order to allow refactoring in
> following patch, interchange the two as prep_irq_for_user_exit() will
> call prep_irq_for_kernel_enabled_exit().
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
> This series applies on top of Nic's series to speed up interrupt return on 64s
Thanks for rebasing it.
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
>
> arch/powerpc/kernel/interrupt.c | 32 ++++++++++++++++----------------
> 1 file changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> index 74c995a42399..539455c62c5b 100644
> --- a/arch/powerpc/kernel/interrupt.c
> +++ b/arch/powerpc/kernel/interrupt.c
> @@ -40,33 +40,27 @@ static inline bool exit_must_hard_disable(void)
> #endif
>
> /*
> - * local irqs must be disabled. Returns false if the caller must re-enable
> - * them, check for new work, and try again.
> - *
> - * This should be called with local irqs disabled, but if they were previously
> - * enabled when the interrupt handler returns (indicating a process-context /
> - * synchronous interrupt) then irqs_enabled should be true.
> + * restartable is true then EE/RI can be left on because interrupts are handled
> + * with a restart sequence.
> */
> -static notrace __always_inline bool prep_irq_for_user_exit(void)
> +static notrace __always_inline bool prep_irq_for_kernel_enabled_exit(bool restartable)
> {
> - user_enter_irqoff();
> /* This must be done with RI=1 because tracing may touch vmaps */
> trace_hardirqs_on();
>
> #ifdef CONFIG_PPC32
> __hard_EE_RI_disable();
> #else
> - if (exit_must_hard_disable())
> + if (exit_must_hard_disable() || !restartable)
> __hard_EE_RI_disable();
>
> /* This pattern matches prep_irq_for_idle */
> if (unlikely(lazy_irq_pending_nocheck())) {
> - if (exit_must_hard_disable()) {
> + if (exit_must_hard_disable() || !restartable) {
> local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
> __hard_RI_enable();
> }
> trace_hardirqs_off();
> - user_exit_irqoff();
>
> return false;
> }
> @@ -75,27 +69,33 @@ static notrace __always_inline bool prep_irq_for_user_exit(void)
> }
>
> /*
> - * restartable is true then EE/RI can be left on because interrupts are handled
> - * with a restart sequence.
> + * local irqs must be disabled. Returns false if the caller must re-enable
> + * them, check for new work, and try again.
> + *
> + * This should be called with local irqs disabled, but if they were previously
> + * enabled when the interrupt handler returns (indicating a process-context /
> + * synchronous interrupt) then irqs_enabled should be true.
> */
> -static notrace __always_inline bool prep_irq_for_kernel_enabled_exit(bool restartable)
> +static notrace __always_inline bool prep_irq_for_user_exit(void)
> {
> + user_enter_irqoff();
> /* This must be done with RI=1 because tracing may touch vmaps */
> trace_hardirqs_on();
>
> #ifdef CONFIG_PPC32
> __hard_EE_RI_disable();
> #else
> - if (exit_must_hard_disable() || !restartable)
> + if (exit_must_hard_disable())
> __hard_EE_RI_disable();
>
> /* This pattern matches prep_irq_for_idle */
> if (unlikely(lazy_irq_pending_nocheck())) {
> - if (exit_must_hard_disable() || !restartable) {
> + if (exit_must_hard_disable()) {
> local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
> __hard_RI_enable();
> }
> trace_hardirqs_off();
> + user_exit_irqoff();
>
> return false;
> }
> --
> 2.25.0
>
>
prev parent reply other threads:[~2021-06-11 2:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-04 14:56 [PATCH v2 1/4] powerpc/interrupt: Interchange prep_irq_for_{kernel_enabled/user}_exit() Christophe Leroy
2021-06-04 14:56 ` [PATCH v2 2/4] powerpc/interrupt: Refactor prep_irq_for_user_exit() Christophe Leroy
2021-06-11 2:30 ` Nicholas Piggin
2021-06-15 8:37 ` Christophe Leroy
2021-06-17 3:33 ` Nicholas Piggin
2021-06-04 14:56 ` [PATCH v2 3/4] powerpc/interrupt: Rename and lightly change syscall_exit_prepare_main() Christophe Leroy
2021-06-11 2:32 ` Nicholas Piggin
2021-06-04 14:56 ` [PATCH v2 4/4] powerpc/interrupt: Refactor interrupt_exit_user_prepare() Christophe Leroy
2021-06-11 2:26 ` Nicholas Piggin [this message]
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