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 X-Spam-Level: X-Spam-Status: No, score=-14.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C515EC433E1 for ; Mon, 24 Aug 2020 10:24:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C7BF20738 for ; Mon, 24 Aug 2020 10:24:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598264655; bh=qXuDFnBsvXIaArgVMjXhFFyxN3x1ZY0+hd+ygcXKUNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HloFsoMdqr9HfcYbVQU5YdKggRXdn9EWT/Jrlhac6uFT3xbn8oiU7dRdd70k3nREw VSigVbTJ0UZj+9fEJzrfvs9VFBcgTkXvLr7A7hkxJ/tG6jptiZcMeD3UteCfrisL+D CzsK9ORzXKrbraaIqFgjB3kubCT4b5kU3B18auBY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726874AbgHXKYN (ORCPT ); Mon, 24 Aug 2020 06:24:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:50518 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726701AbgHXKYA (ORCPT ); Mon, 24 Aug 2020 06:24:00 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 171DA2074D; Mon, 24 Aug 2020 10:23:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598264639; bh=qXuDFnBsvXIaArgVMjXhFFyxN3x1ZY0+hd+ygcXKUNU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iiPJdcFYB44QuROyS9nOXXZBvpQjEwHM5Dtb9Nl7n1WV7lutLIT4F1y/0aHHvfJC9 GdDtt2i3lV3omjn2/uxyStueATytz/2wBAGJPW/12te8miaSPLhTOPcdVSWqaBxlgP +MKvGCv8uOU1O/LwEKUbY8F1om3ICj847ak9W9t4= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kA9dt-006BQc-H7; Mon, 24 Aug 2020 11:23:57 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Cc: Bjorn Helgaas , Gregory Clement , Jason Cooper , Laurentiu Tudor , Thomas Gleixner , Valentin Schneider Subject: [PATCH 9/9] irqchip/gic-v2, v3: Prevent SW resends entirely Date: Mon, 24 Aug 2020 11:23:17 +0100 Message-Id: <20200824102317.1038259-10-maz@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200824102317.1038259-1-maz@kernel.org> References: <20200824102317.1038259-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, bhelgaas@google.com, gregory.clement@bootlin.com, jason@lakedaemon.net, laurentiu.tudor@nxp.com, tglx@linutronix.de, valentin.schneider@arm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Valentin Schneider The GIC irqchips can now use a HW resend when a retrigger is invoked by check_irq_resend(). However, should the HW resend fail, check_irq_resend() will still attempt to trigger a SW resend, which is still a bad idea for the GICs. Prevent this from happening by setting IRQD_HANDLE_ENFORCE_IRQCTX on all GIC IRQs. Technically per-cpu IRQs do not need this, as their flow handlers never set IRQS_PENDING, but this aligns all IRQs wrt context enforcement: this also forces all GIC IRQ handling to happen in IRQ context (as defined by in_irq()). Signed-off-by: Valentin Schneider Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200730170321.31228-3-valentin.schneider@arm.com --- drivers/irqchip/irq-gic-v3.c | 5 ++++- drivers/irqchip/irq-gic.c | 6 +++++- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index b507bc7c5cda..4e9387aafed8 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -1279,6 +1279,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { struct irq_chip *chip = &gic_chip; + struct irq_data *irqd = irq_desc_get_irq_data(irq_to_desc(irq)); if (static_branch_likely(&supports_deactivate_key)) chip = &gic_eoimode1_chip; @@ -1296,7 +1297,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, irq_domain_set_info(d, irq, hw, chip, d->host_data, handle_fasteoi_irq, NULL, NULL); irq_set_probe(irq); - irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq))); + irqd_set_single_target(irqd); break; case LPI_RANGE: @@ -1310,6 +1311,8 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, return -EPERM; } + /* Prevents SW retriggers which mess up the ACK/EOI ordering */ + irqd_set_handle_enforce_irqctx(irqd); return 0; } diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index e92ee2b6d7a5..b59bcef69bf3 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -975,6 +975,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { struct gic_chip_data *gic = d->host_data; + struct irq_data *irqd = irq_desc_get_irq_data(irq_to_desc(irq)); if (hw < 32) { irq_set_percpu_devid(irq); @@ -984,8 +985,11 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, irq_domain_set_info(d, irq, hw, &gic->chip, d->host_data, handle_fasteoi_irq, NULL, NULL); irq_set_probe(irq); - irqd_set_single_target(irq_desc_get_irq_data(irq_to_desc(irq))); + irqd_set_single_target(irqd); } + + /* Prevents SW retriggers which mess up the ACK/EOI ordering */ + irqd_set_handle_enforce_irqctx(irqd); return 0; } -- 2.27.0