From patchwork Wed Feb 9 15:35:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Rutland X-Patchwork-Id: 12740395 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 52E85C433F5 for ; Wed, 9 Feb 2022 15:41:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Ia0voph1Wv6R1OxsLQgdDYa1CXfeg3mSpdSKXn6+zBs=; b=F0uqBb0oKr9W3E IQLIevdLzn3oki915mbaiKAztwMN46kmBiNXGEwMQ6uSeVrF6IhrjD4CdeilrcudD9sJ7wXiTiIpH ShjbA8dVcEEHHc1ci0Nrb50Z8hC17X4TVPyk47KoJKmpn5RS6f3N2KCwi582DQ83ERDytsVt1ZHy2 28Ilj0nNpGdH5r/6Nzd0OlZA8+QHM3HVs+EktojxOx6qFn6y/Cb/E4Ahv5SWOkLPzfe7lw/RHOUjM FLiX5SpCSZK+qyLfdiuDzRD572p4+RH6x6t+EXK44Hc4ygWQZfzvYrbw2ZL0nFyfLa4yHAd03xsD/ SX6U0PEUCZmC3cvHZYhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHp4j-000dOf-O0; Wed, 09 Feb 2022 15:40:10 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nHp0c-000bof-6a for linux-arm-kernel@lists.infradead.org; Wed, 09 Feb 2022 15:35:55 +0000 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 E402812FC; Wed, 9 Feb 2022 07:35:52 -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 CCF7B3F73B; Wed, 9 Feb 2022 07:35:50 -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 v3 3/7] sched/preempt: simplify irqentry_exit_cond_resched() callers Date: Wed, 9 Feb 2022 15:35:31 +0000 Message-Id: <20220209153535.818830-4-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220209153535.818830-1-mark.rutland@arm.com> References: <20220209153535.818830-1-mark.rutland@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220209_073554_388655_11BD5911 X-CRM114-Status: GOOD ( 11.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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 Cc: Andy Lutomirski Cc: Ard Biesheuvel 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();