From patchwork Fri Mar 6 13:03:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 11423883 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2AEB114E3 for ; Fri, 6 Mar 2020 13:09:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15E7624655 for ; Fri, 6 Mar 2020 13:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727065AbgCFNIo (ORCPT ); Fri, 6 Mar 2020 08:08:44 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:53321 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727061AbgCFNIo (ORCPT ); Fri, 6 Mar 2020 08:08:44 -0500 Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jACiV-0003fr-IV; Fri, 06 Mar 2020 14:08:39 +0100 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id E62CA10409D; Fri, 6 Mar 2020 14:08:38 +0100 (CET) Message-Id: <20200306130623.775200917@linutronix.de> User-Agent: quilt/0.65 Date: Fri, 06 Mar 2020 14:03:45 +0100 From: Thomas Gleixner To: LKML Cc: Marc Zyngier , x86@kernel.org, Bjorn Helgaas , linux-pci@vger.kernel.org, Keith Busch , Kuppuswamy Sathyanarayanan Subject: [patch 4/7] genirq: Add return value to check_irq_resend() References: <20200306130341.199467200@linutronix.de> MIME-Version: 1.0 X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org In preparation for an interrupt injection interface which can be used safely by error injection mechanisms. e.g. PCI-E/ AER, add a return value to check_irq_resend() so errors can be propagated to the caller. Split out the software resend code so the ugly #ifdef in check_irq_resend() goes away and the whole thing becomes readable. Fix up the caller in debugfs. The caller in irq_startup() does not care about the return value as this is unconditionally invoked for all interrupts and the resend is best effort anyway. Signed-off-by: Thomas Gleixner Acked-by: Marc Zyngier --- kernel/irq/debugfs.c | 3 - kernel/irq/internals.h | 2 - kernel/irq/resend.c | 83 ++++++++++++++++++++++++++++--------------------- 3 files changed, 51 insertions(+), 37 deletions(-) --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -218,8 +218,7 @@ static ssize_t irq_debug_write(struct fi err = -EINVAL; } else { desc->istate |= IRQS_PENDING; - check_irq_resend(desc); - err = 0; + err = check_irq_resend(desc); } raw_spin_unlock_irqrestore(&desc->lock, flags); --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -108,7 +108,7 @@ irqreturn_t handle_irq_event_percpu(stru irqreturn_t handle_irq_event(struct irq_desc *desc); /* Resending of interrupts :*/ -void check_irq_resend(struct irq_desc *desc); +int check_irq_resend(struct irq_desc *desc); bool irq_wait_for_poll(struct irq_desc *desc); void __irq_wake_thread(struct irq_desc *desc, struct irqaction *action); --- a/kernel/irq/resend.c +++ b/kernel/irq/resend.c @@ -47,6 +47,43 @@ static void resend_irqs(unsigned long ar /* Tasklet to handle resend: */ static DECLARE_TASKLET(resend_tasklet, resend_irqs, 0); +static int irq_sw_resend(struct irq_desc *desc) +{ + unsigned int irq = irq_desc_get_irq(desc); + + /* + * Validate whether this interrupt can be safely injected from + * non interrupt context + */ + if (handle_enforce_irqctx(&desc->irq_data)) + return -EINVAL; + + /* + * If the interrupt is running in the thread context of the parent + * irq we need to be careful, because we cannot trigger it + * directly. + */ + if (irq_settings_is_nested_thread(desc)) { + /* + * If the parent_irq is valid, we retrigger the parent, + * otherwise we do nothing. + */ + if (!desc->parent_irq) + return -EINVAL; + irq = desc->parent_irq; + } + + /* Set it pending and activate the softirq: */ + set_bit(irq, irqs_resend); + tasklet_schedule(&resend_tasklet); + return 0; +} + +#else +static int irq_sw_resend(struct irq_desc *desc) +{ + return -EINVAL; +} #endif /* @@ -54,50 +91,28 @@ static DECLARE_TASKLET(resend_tasklet, r * * Is called with interrupts disabled and desc->lock held. */ -void check_irq_resend(struct irq_desc *desc) +int check_irq_resend(struct irq_desc *desc) { /* - * We do not resend level type interrupts. Level type - * interrupts are resent by hardware when they are still - * active. Clear the pending bit so suspend/resume does not - * get confused. + * We do not resend level type interrupts. Level type interrupts + * are resent by hardware when they are still active. Clear the + * pending bit so suspend/resume does not get confused. */ if (irq_settings_is_level(desc)) { desc->istate &= ~IRQS_PENDING; - return; + return -EINVAL; } + if (desc->istate & IRQS_REPLAY) - return; + return -EBUSY; + if (desc->istate & IRQS_PENDING) { desc->istate &= ~IRQS_PENDING; desc->istate |= IRQS_REPLAY; - if ((!desc->irq_data.chip->irq_retrigger || - !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) && - !handle_enforce_irqctx(&desc->irq_data)) { -#ifdef CONFIG_HARDIRQS_SW_RESEND - unsigned int irq = irq_desc_get_irq(desc); - - /* - * If the interrupt is running in the thread - * context of the parent irq we need to be - * careful, because we cannot trigger it - * directly. - */ - if (irq_settings_is_nested_thread(desc)) { - /* - * If the parent_irq is valid, we - * retrigger the parent, otherwise we - * do nothing. - */ - if (!desc->parent_irq) - return; - irq = desc->parent_irq; - } - /* Set it pending and activate the softirq: */ - set_bit(irq, irqs_resend); - tasklet_schedule(&resend_tasklet); -#endif - } + if (!desc->irq_data.chip->irq_retrigger || + !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) + return irq_sw_resend(desc); } + return 0; }