From: Qi Zheng <zhengqi.arch@bytedance.com> To: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org> Subject: Re: [RFC PATCH 2/2] arm64: support HAVE_IRQ_EXIT_ON_IRQ_STACK Date: Thu, 7 Jul 2022 23:00:37 +0800 [thread overview] Message-ID: <33a63e76-fb71-2b9e-3b3c-cc6f7a675cf3@bytedance.com> (raw) In-Reply-To: <CAK8P3a17A1t=qkyToQNVnuVfGPp-7VpFx5qJ-gmpyrkJ3yRXTw@mail.gmail.com> On 2022/7/7 22:41, Arnd Bergmann wrote: > On Thu, Jul 7, 2022 at 3:38 PM Qi Zheng <zhengqi.arch@bytedance.com> wrote: >> On 2022/7/7 20:49, Arnd Bergmann wrote: >>> On Thu, Jul 7, 2022 at 1:05 PM Qi Zheng <zhengqi.arch@bytedance.com> wrote: >> * Restore the SP from the FP, and restore the FP and LR from >> the frame >> * record. >> */ >> - mov sp, x29 >> +999: mov sp, x29 >> ldp x29, x30, [sp], #16 >> #ifdef CONFIG_SHADOW_CALL_STACK >> ldp scs_sp, xzr, [sp], #16 >> >> But this also requires a new parameter in do_interrupt_handler. >> >> I also considered implementing call_on_irq_stack() for nmi and irq >> separately, but later think it's unnecessary. > > What I had in mind was something along the lines of > > diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c > index 56cefd33eb8e..432042b91588 100644 > --- a/arch/arm64/kernel/entry-common.c > +++ b/arch/arm64/kernel/entry-common.c > @@ -270,10 +270,7 @@ static void do_interrupt_handler(struct pt_regs *regs, > { > struct pt_regs *old_regs = set_irq_regs(regs); > > - if (on_thread_stack()) > - call_on_irq_stack(regs, handler); > - else > - handler(regs); > + handler(regs); > > set_irq_regs(old_regs); > } > @@ -473,16 +470,31 @@ static void noinstr el1_interrupt(struct pt_regs *regs, > __el1_irq(regs, handler); > } > > -asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) > +static void noinstr el1_irq(struct pt_regs *regs) > { > el1_interrupt(regs, handle_arch_irq); > } > > -asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) > +asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) > +{ > + if (on_thread_stack()) > + call_on_irq_stack(regs, el1_irq); IMO, this can't work. Because el1_interrupt() will invoke arm64_preempt_schedule_irq(), which will cause scheduling on the IRQ stack. Thanks, Qi > + else > + el1_irq(regs); > +} > + > +static void noinstr el1_fiq(struct pt_regs *regs) > { > el1_interrupt(regs, handle_arch_fiq); > } > > +asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) > +{ > + if (on_thread_stack()) > + call_on_irq_stack(regs, el1_fiq); > + else > + el1_fiq(regs); > +} > + > asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs) > { > unsigned long esr = read_sysreg(esr_el1); > @@ -713,7 +731,7 @@ static void noinstr > __el0_irq_handler_common(struct pt_regs *regs) > > asmlinkage void noinstr el0t_64_irq_handler(struct pt_regs *regs) > { > - __el0_irq_handler_common(regs); > + call_on_irq_stack(regs, __el0_irq_handler_common); > } > > static void noinstr __el0_fiq_handler_common(struct pt_regs *regs) > @@ -723,7 +741,7 @@ static void noinstr > __el0_fiq_handler_common(struct pt_regs *regs) > > asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs) > { > - __el0_fiq_handler_common(regs); > + call_on_irq_stack(regs, __el0_fiq_handler_common); > } > > static void noinstr __el0_error_handler_common(struct pt_regs *regs) > @@ -807,12 +825,12 @@ asmlinkage void noinstr > el0t_32_sync_handler(struct pt_regs *regs) > > asmlinkage void noinstr el0t_32_irq_handler(struct pt_regs *regs) > { > - __el0_irq_handler_common(regs); > + call_on_irq_stack(regs, __el0_irq_handler_common); > } > > asmlinkage void noinstr el0t_32_fiq_handler(struct pt_regs *regs) > { > - __el0_fiq_handler_common(regs); > + call_on_irq_stack(regs, __el0_fiq_handler_common); > } > > asmlinkage void noinstr el0t_32_error_handler(struct pt_regs *regs) > > Not sure if that works. > > Arnd -- Thanks, Qi
WARNING: multiple messages have this Message-ID (diff)
From: Qi Zheng <zhengqi.arch@bytedance.com> To: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Linux ARM <linux-arm-kernel@lists.infradead.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org> Subject: Re: [RFC PATCH 2/2] arm64: support HAVE_IRQ_EXIT_ON_IRQ_STACK Date: Thu, 7 Jul 2022 23:00:37 +0800 [thread overview] Message-ID: <33a63e76-fb71-2b9e-3b3c-cc6f7a675cf3@bytedance.com> (raw) In-Reply-To: <CAK8P3a17A1t=qkyToQNVnuVfGPp-7VpFx5qJ-gmpyrkJ3yRXTw@mail.gmail.com> On 2022/7/7 22:41, Arnd Bergmann wrote: > On Thu, Jul 7, 2022 at 3:38 PM Qi Zheng <zhengqi.arch@bytedance.com> wrote: >> On 2022/7/7 20:49, Arnd Bergmann wrote: >>> On Thu, Jul 7, 2022 at 1:05 PM Qi Zheng <zhengqi.arch@bytedance.com> wrote: >> * Restore the SP from the FP, and restore the FP and LR from >> the frame >> * record. >> */ >> - mov sp, x29 >> +999: mov sp, x29 >> ldp x29, x30, [sp], #16 >> #ifdef CONFIG_SHADOW_CALL_STACK >> ldp scs_sp, xzr, [sp], #16 >> >> But this also requires a new parameter in do_interrupt_handler. >> >> I also considered implementing call_on_irq_stack() for nmi and irq >> separately, but later think it's unnecessary. > > What I had in mind was something along the lines of > > diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c > index 56cefd33eb8e..432042b91588 100644 > --- a/arch/arm64/kernel/entry-common.c > +++ b/arch/arm64/kernel/entry-common.c > @@ -270,10 +270,7 @@ static void do_interrupt_handler(struct pt_regs *regs, > { > struct pt_regs *old_regs = set_irq_regs(regs); > > - if (on_thread_stack()) > - call_on_irq_stack(regs, handler); > - else > - handler(regs); > + handler(regs); > > set_irq_regs(old_regs); > } > @@ -473,16 +470,31 @@ static void noinstr el1_interrupt(struct pt_regs *regs, > __el1_irq(regs, handler); > } > > -asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) > +static void noinstr el1_irq(struct pt_regs *regs) > { > el1_interrupt(regs, handle_arch_irq); > } > > -asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) > +asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) > +{ > + if (on_thread_stack()) > + call_on_irq_stack(regs, el1_irq); IMO, this can't work. Because el1_interrupt() will invoke arm64_preempt_schedule_irq(), which will cause scheduling on the IRQ stack. Thanks, Qi > + else > + el1_irq(regs); > +} > + > +static void noinstr el1_fiq(struct pt_regs *regs) > { > el1_interrupt(regs, handle_arch_fiq); > } > > +asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) > +{ > + if (on_thread_stack()) > + call_on_irq_stack(regs, el1_fiq); > + else > + el1_fiq(regs); > +} > + > asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs) > { > unsigned long esr = read_sysreg(esr_el1); > @@ -713,7 +731,7 @@ static void noinstr > __el0_irq_handler_common(struct pt_regs *regs) > > asmlinkage void noinstr el0t_64_irq_handler(struct pt_regs *regs) > { > - __el0_irq_handler_common(regs); > + call_on_irq_stack(regs, __el0_irq_handler_common); > } > > static void noinstr __el0_fiq_handler_common(struct pt_regs *regs) > @@ -723,7 +741,7 @@ static void noinstr > __el0_fiq_handler_common(struct pt_regs *regs) > > asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs) > { > - __el0_fiq_handler_common(regs); > + call_on_irq_stack(regs, __el0_fiq_handler_common); > } > > static void noinstr __el0_error_handler_common(struct pt_regs *regs) > @@ -807,12 +825,12 @@ asmlinkage void noinstr > el0t_32_sync_handler(struct pt_regs *regs) > > asmlinkage void noinstr el0t_32_irq_handler(struct pt_regs *regs) > { > - __el0_irq_handler_common(regs); > + call_on_irq_stack(regs, __el0_irq_handler_common); > } > > asmlinkage void noinstr el0t_32_fiq_handler(struct pt_regs *regs) > { > - __el0_fiq_handler_common(regs); > + call_on_irq_stack(regs, __el0_fiq_handler_common); > } > > asmlinkage void noinstr el0t_32_error_handler(struct pt_regs *regs) > > Not sure if that works. > > Arnd -- Thanks, Qi _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-07-07 15:01 UTC|newest] Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-07-07 11:05 [RFC PATCH 0/2] arm64: run softirqs on the per-CPU IRQ stack Qi Zheng 2022-07-07 11:05 ` Qi Zheng 2022-07-07 11:05 ` [RFC PATCH 1/2] " Qi Zheng 2022-07-07 11:05 ` Qi Zheng 2022-07-07 12:58 ` Arnd Bergmann 2022-07-07 12:58 ` Arnd Bergmann 2022-07-07 13:43 ` Qi Zheng 2022-07-07 13:43 ` Qi Zheng 2022-07-07 13:53 ` Arnd Bergmann 2022-07-07 13:53 ` Arnd Bergmann 2022-07-07 15:05 ` Qi Zheng 2022-07-07 15:05 ` Qi Zheng 2022-07-08 2:56 ` kernel test robot 2022-07-07 11:05 ` [RFC PATCH 2/2] arm64: support HAVE_IRQ_EXIT_ON_IRQ_STACK Qi Zheng 2022-07-07 11:05 ` Qi Zheng 2022-07-07 12:49 ` Arnd Bergmann 2022-07-07 12:49 ` Arnd Bergmann 2022-07-07 13:38 ` Qi Zheng 2022-07-07 13:38 ` Qi Zheng 2022-07-07 14:41 ` Arnd Bergmann 2022-07-07 14:41 ` Arnd Bergmann 2022-07-07 15:00 ` Qi Zheng [this message] 2022-07-07 15:00 ` Qi Zheng 2022-07-07 20:55 ` Arnd Bergmann 2022-07-07 20:55 ` Arnd Bergmann 2022-07-08 3:13 ` Qi Zheng 2022-07-08 3:13 ` Qi Zheng 2022-07-08 8:52 ` Arnd Bergmann 2022-07-08 8:52 ` Arnd Bergmann 2022-07-08 9:13 ` Qi Zheng 2022-07-08 9:13 ` Qi Zheng
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