From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E154DC433F5 for ; Thu, 21 Oct 2021 18:03:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8672619E5 for ; Thu, 21 Oct 2021 18:03:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232560AbhJUSGA (ORCPT ); Thu, 21 Oct 2021 14:06:00 -0400 Received: from foss.arm.com ([217.140.110.172]:46118 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232575AbhJUSFm (ORCPT ); Thu, 21 Oct 2021 14:05:42 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 933421063; Thu, 21 Oct 2021 11:03:26 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B5A143F70D; Thu, 21 Oct 2021 11:03:23 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: aou@eecs.berkeley.edu, catalin.marinas@arm.com, deanbo422@gmail.com, green.hu@gmail.com, guoren@kernel.org, jonas@southpole.se, kernelfans@gmail.com, linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk, mark.rutland@arm.com, maz@kernel.org, nickhu@andestech.com, palmer@dabbelt.com, paulmck@kernel.org, paul.walmsley@sifive.com, peterz@infradead.org, shorne@gmail.com, stefan.kristiansson@saunalahti.fi, tglx@linutronix.de, torvalds@linux-foundation.org, tsbogend@alpha.franken.de, vgupta@kernel.org, will@kernel.org Subject: [PATCH 10/15] irq: arm64: perform irqentry in entry code Date: Thu, 21 Oct 2021 19:02:31 +0100 Message-Id: <20211021180236.37428-11-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20211021180236.37428-1-mark.rutland@arm.com> References: <20211021180236.37428-1-mark.rutland@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation for removing HANDLE_DOMAIN_IRQ_IRQENTRY, have arch/arm64 perform all the irqentry accounting in its entry code. As arch/arm64 already performs portions of the irqentry logic in enter_from_kernel_mode() and exit_to_kernel_mode(), including rcu_irq_{enter,exit}(), the only additional calls that need to be made are to irq_{enter,exit}_rcu(). Removing the calls to rcu_irq_{enter,exit}() from handle_domain_irq() ensures that we inform RCU once per IRQ entry and will correctly identify quiescent periods. Since we should not call irq_{enter,exit}_rcu() when entering a pseudo-NMI, el1_interrupt() is reworked to have separate __el1_irq() and __el1_pnmi() paths for regular IRQ and psuedo-NMI entry, with irq_{enter,exit}_irq() only called for the former. In preparation for removing HANDLE_DOMAIN_IRQ, the irq regs are managed in do_interrupt_handler() for both regular IRQ and pseudo-NMI. This is currently redundant, but not harmful. For clarity the preemption logic is moved into __el1_irq(). We should never preempt within a pseudo-NMI, and arm64_enter_nmi() already enforces this by incrementing the preempt_count, but it's clearer if we never invoke the preemption logic when entering a pseudo-NMI. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Marc Zyngier Cc: Thomas Gleixner Cc: Will Deacon --- arch/arm64/Kconfig | 1 - arch/arm64/kernel/entry-common.c | 52 ++++++++++++++++++++++++---------------- 2 files changed, 31 insertions(+), 22 deletions(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 553239a5a5f7..5c7ae4c3954b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -134,7 +134,6 @@ config ARM64 select GENERIC_GETTIMEOFDAY select GENERIC_VDSO_TIME_NS select HANDLE_DOMAIN_IRQ - select HANDLE_DOMAIN_IRQ_IRQENTRY select HARDIRQS_SW_RESEND select HAVE_MOVE_PMD select HAVE_MOVE_PUD diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 32f9796c4ffe..f7408edf8571 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -219,22 +220,6 @@ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs) lockdep_hardirqs_on(CALLER_ADDR0); } -static void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) -{ - if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) - arm64_enter_nmi(regs); - else - enter_from_kernel_mode(regs); -} - -static void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs) -{ - if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) - arm64_exit_nmi(regs); - else - exit_to_kernel_mode(regs); -} - static void __sched arm64_preempt_schedule_irq(void) { lockdep_assert_irqs_disabled(); @@ -263,10 +248,14 @@ static void __sched arm64_preempt_schedule_irq(void) static void do_interrupt_handler(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { + struct pt_regs *old_regs = set_irq_regs(regs); + if (on_thread_stack()) call_on_irq_stack(regs, handler); else handler(regs); + + set_irq_regs(old_regs); } extern void (*handle_arch_irq)(struct pt_regs *); @@ -432,13 +421,22 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) } } -static void noinstr el1_interrupt(struct pt_regs *regs, - void (*handler)(struct pt_regs *)) +static __always_inline void __el1_pnmi(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) { - write_sysreg(DAIF_PROCCTX_NOIRQ, daif); + arm64_enter_nmi(regs); + do_interrupt_handler(regs, handler); + arm64_exit_nmi(regs); +} + +static __always_inline void __el1_irq(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) +{ + enter_from_kernel_mode(regs); - enter_el1_irq_or_nmi(regs); + irq_enter_rcu(); do_interrupt_handler(regs, handler); + irq_exit_rcu(); /* * Note: thread_info::preempt_count includes both thread_info::count @@ -449,7 +447,17 @@ static void noinstr el1_interrupt(struct pt_regs *regs, READ_ONCE(current_thread_info()->preempt_count) == 0) arm64_preempt_schedule_irq(); - exit_el1_irq_or_nmi(regs); + exit_to_kernel_mode(regs); +} +static void noinstr el1_interrupt(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) +{ + write_sysreg(DAIF_PROCCTX_NOIRQ, daif); + + if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) + __el1_pnmi(regs, handler); + else + __el1_irq(regs, handler); } asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) @@ -667,7 +675,9 @@ static void noinstr el0_interrupt(struct pt_regs *regs, if (regs->pc & BIT(55)) arm64_apply_bp_hardening(); + irq_enter_rcu(); do_interrupt_handler(regs, handler); + irq_exit_rcu(); exit_to_user_mode(regs); } -- 2.11.0