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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3F314C433EF for ; Mon, 14 Feb 2022 16:52:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347952AbiBNQwr (ORCPT ); Mon, 14 Feb 2022 11:52:47 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:33054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347185AbiBNQwl (ORCPT ); Mon, 14 Feb 2022 11:52:41 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 92F8265149 for ; Mon, 14 Feb 2022 08:52:33 -0800 (PST) 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 626721480; Mon, 14 Feb 2022 08:52:33 -0800 (PST) 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 679673F70D; Mon, 14 Feb 2022 08:52:31 -0800 (PST) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: ardb@kernel.org, bp@alien8.de, catalin.marinas@arm.com, dave.hansen@linux.intel.com, frederic@kernel.org, james.morse@arm.com, joey.gouly@arm.com, juri.lelli@redhat.com, linux-kernel@vger.kernel.org, luto@kernel.org, mark.rutland@arm.com, mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, valentin.schneider@arm.com, will@kernel.org Subject: [PATCH v4 3/7] sched/preempt: simplify irqentry_exit_cond_resched() callers Date: Mon, 14 Feb 2022 16:52:12 +0000 Message-Id: <20220214165216.2231574-4-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220214165216.2231574-1-mark.rutland@arm.com> References: <20220214165216.2231574-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently callers of irqentry_exit_cond_resched() need to be aware of whether the function should be indirected via a static call, leading to ugly ifdeffery in callers. Save them the hassle with a static inline wrapper that does the right thing. The raw_irqentry_exit_cond_resched() will also be useful in subsequent patches which will add conditional wrappers for preemption functions. Note: in arch/x86/entry/common.c, xen_pv_evtchn_do_upcall() always calls irqentry_exit_cond_resched() directly, even when PREEMPT_DYNAMIC is in use. I believe this is a latent bug (which this patch corrects), but I'm not entirely certain this wasn't deliberate. Signed-off-by: Mark Rutland Acked-by: Ard Biesheuvel Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Juri Lelli Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Valentin Schneider --- include/linux/entry-common.h | 9 ++++++--- kernel/entry/common.c | 12 ++++-------- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index a01ac1a0a292..dfd84c59b144 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -454,11 +454,14 @@ irqentry_state_t noinstr irqentry_enter(struct pt_regs *regs); * * Conditional reschedule with additional sanity checks. */ -void irqentry_exit_cond_resched(void); +void raw_irqentry_exit_cond_resched(void); #ifdef CONFIG_PREEMPT_DYNAMIC -#define irqentry_exit_cond_resched_dynamic_enabled irqentry_exit_cond_resched +#define irqentry_exit_cond_resched_dynamic_enabled raw_irqentry_exit_cond_resched #define irqentry_exit_cond_resched_dynamic_disabled NULL -DECLARE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); +DECLARE_STATIC_CALL(irqentry_exit_cond_resched, raw_irqentry_exit_cond_resched); +#define irqentry_exit_cond_resched() static_call(irqentry_exit_cond_resched)() +#else +#define irqentry_exit_cond_resched() raw_irqentry_exit_cond_resched() #endif /** diff --git a/kernel/entry/common.c b/kernel/entry/common.c index bad713684c2e..1739ca79613b 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -380,7 +380,7 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs) return ret; } -void irqentry_exit_cond_resched(void) +void raw_irqentry_exit_cond_resched(void) { if (!preempt_count()) { /* Sanity check RCU and thread stack */ @@ -392,7 +392,7 @@ void irqentry_exit_cond_resched(void) } } #ifdef CONFIG_PREEMPT_DYNAMIC -DEFINE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); +DEFINE_STATIC_CALL(irqentry_exit_cond_resched, raw_irqentry_exit_cond_resched); #endif noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) @@ -420,13 +420,9 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) } instrumentation_begin(); - if (IS_ENABLED(CONFIG_PREEMPTION)) { -#ifdef CONFIG_PREEMPT_DYNAMIC - static_call(irqentry_exit_cond_resched)(); -#else + if (IS_ENABLED(CONFIG_PREEMPTION)) irqentry_exit_cond_resched(); -#endif - } + /* Covers both tracing and lockdep */ trace_hardirqs_on(); instrumentation_end(); -- 2.30.2