From patchwork Tue Aug 19 16:45:56 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Thompson X-Patchwork-Id: 4744721 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 824049F375 for ; Tue, 19 Aug 2014 16:54:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7215F2010B for ; Tue, 19 Aug 2014 16:54:06 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6171F20103 for ; Tue, 19 Aug 2014 16:54:05 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XJmck-00019c-TQ; Tue, 19 Aug 2014 16:51:06 +0000 Received: from mail-wi0-f181.google.com ([209.85.212.181]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XJmcg-0000r0-8G for linux-arm-kernel@lists.infradead.org; Tue, 19 Aug 2014 16:51:03 +0000 Received: by mail-wi0-f181.google.com with SMTP id bs8so5617668wib.2 for ; Tue, 19 Aug 2014 09:50:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=KHwUZqXCggmg6InxKDyZXGQdEb0a6jwKgUU+J7920BA=; b=gxQqQq3JXl0qr99FKpW3eoL1QEvPtWZ+LwEcKSFXB1qQHsPMUs+UI/IaMkr2RB6ItU O6m0SfULTcj5EGcBr8vBi/9mFOyABczawC7Hb6KVS2/8RlcK7ToGeqDtCT7W4Jc9cZaY uD/dn1ZztdsM0urtb8jtovoApCvMiWkAmdLEaSBLLHQeDyC4grhq9ydTbH1ZBCj4Cgxm D5oLEP4cJkqGVBQgnPU7Mz93biA2A4k1WwSPFh8GV9EszfmNah+HMHaMMjMEM16UHCvs bhufp31ssq2N86iGf2l5GWanDuKZIXPYKWq6FRV5GDyN+Z8ugmYnxxgflY9Vq1a3eJT1 7pBQ== X-Gm-Message-State: ALoCoQmkCN6KDKES/T5x0CQZrJCGX2gCiwUut5NdKsWQF32u5tRGtm3b7QXMO0kEi9fqCBrP87O3 X-Received: by 10.180.105.6 with SMTP id gi6mr7980273wib.81.1408467040302; Tue, 19 Aug 2014 09:50:40 -0700 (PDT) Received: from sundance.lan (cpc4-aztw19-0-0-cust157.18-1.cable.virginm.net. [82.33.25.158]) by mx.google.com with ESMTPSA id gc8sm36225wic.3.2014.08.19.09.50.37 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 19 Aug 2014 09:50:39 -0700 (PDT) From: Daniel Thompson To: Russell King Subject: [PATCH v10 06/19] irqchip: gic: Provide support for interrupt grouping Date: Tue, 19 Aug 2014 17:45:56 +0100 Message-Id: <1408466769-20004-7-git-send-email-daniel.thompson@linaro.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1408466769-20004-1-git-send-email-daniel.thompson@linaro.org> References: <1408369264-14242-1-git-send-email-daniel.thompson@linaro.org> <1408466769-20004-1-git-send-email-daniel.thompson@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140819_095102_588960_214CCD8B X-CRM114-Status: GOOD ( 24.30 ) X-Spam-Score: -0.7 (/) Cc: Nicolas Pitre , Catalin Marinas , Linus Walleij , Sricharan R , Fabio Estevam , Daniel Thompson , Nicolas Pitre , Anton Vorontsov , Ben Dooks , kgdb-bugreport@lists.sourceforge.net, kernel-team@android.com, Dave Martin , linaro-kernel@lists.linaro.org, Jason Cooper , patches@linaro.org, Marc Zyngier , John Stultz , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Colin Cross , Frederic Weisbecker , Christoffer Dall X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP All GIC hardware except GICv1-without-TrustZone support provides a means to group exceptions into group 0 (which can optionally be signally using use FIQ) and group 1. The kernel currently provides no means to exploit this. This patch alters the initialization of the GIC to place all interrupts into group 1 which is the foundational requirement to meaningfully use FIQ. Note that the hardware functionality is unavailable to the kernel when a secure monitor is present because access to the grouping registers are prohibited outside "secure world" (this feature allows grouping to be used to allow hardware peripherals to send interrupts into the secure world). The GIC driver will automatically detect this and disable its attempts to group interrupts. On systems without TrustZone support the kernel has the power to route interrupt sources to FIQ, potentially allowing a driver to exploit the NMI-like properties of FIQ. Tested on Freescale i.MX6 (quad A9), STiH416 (dual A9) and a self-written qemu GICv2 model. Signed-off-by: Daniel Thompson Cc: Thomas Gleixner Cc: Jason Cooper Cc: Nicolas Pitre Cc: Christoffer Dall Cc: Sricharan R Cc: Marc Zyngier Acked-by: Dirk Behme --- drivers/irqchip/irq-gic.c | 99 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 94 insertions(+), 5 deletions(-) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 4b959e6..423707c 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -41,6 +41,9 @@ #include #include +#ifdef CONFIG_FIQ +#include +#endif #include #include #include @@ -68,6 +71,9 @@ struct gic_chip_data { #ifdef CONFIG_GIC_NON_BANKED void __iomem *(*get_base)(union gic_base *); #endif +#ifdef CONFIG_FIQ + bool fiq_enable; +#endif }; static DEFINE_RAW_SPINLOCK(irq_controller_lock); @@ -131,6 +137,16 @@ static inline void gic_set_base_accessor(struct gic_chip_data *data, #define gic_set_base_accessor(d, f) #endif +#ifdef CONFIG_FIQ +static inline bool gic_data_fiq_enable(struct gic_chip_data *data) +{ + return data->fiq_enable; +} +#else +static inline bool gic_data_fiq_enable( + struct gic_chip_data *data) { return false; } +#endif + static inline void __iomem *gic_dist_base(struct irq_data *d) { struct gic_chip_data *gic_data = irq_data_get_irq_chip_data(d); @@ -325,6 +341,42 @@ static struct irq_chip gic_chip = { .irq_set_wake = gic_set_wake, }; +#ifdef CONFIG_FIQ +static void __init gic_init_fiq(struct gic_chip_data *gic, + irq_hw_number_t first_irq, + unsigned int num_irqs) +{ + void __iomem *dist_base = gic_data_dist_base(gic_data); + unsigned int i; + + /* + * FIQ can only be supported on platforms without an extended irq_eoi + * method (otherwise we take a lock during eoi handling). + */ + if (gic_arch_extn.irq_eoi) + return; + + /* + * If grouping is not available (not implemented or prohibited by + * security mode) these registers a read-as-zero/write-ignored. + * However as a precaution we restore the reset default regardless of + * the result of the test. + */ + writel_relaxed(1, dist_base + GIC_DIST_IGROUP + 0); + gic->fiq_enable = readl_relaxed(dist_base + GIC_DIST_IGROUP + 0); + writel_relaxed(0, dist_base + GIC_DIST_IGROUP + 0); + pr_debug("gic: FIQ support %s\n", + gic->fiq_enable ? "enabled" : "disabled"); + + if (!gic->fiq_enable) + return; +} +#else /* CONFIG_FIQ */ +static inline void gic_init_fiq(struct gic_chip_data *gic, + irq_hw_number_t first_irq, + unsigned int num_irqs) {} +#endif /* CONFIG_FIQ */ + void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq) { if (gic_nr >= MAX_GIC_NR) @@ -373,7 +425,22 @@ static void __init gic_dist_init(struct gic_chip_data *gic) gic_dist_config(base, gic_irqs, NULL); - writel_relaxed(1, base + GIC_DIST_CTRL); + /* + * Optionally set all global interrupts to be group 1. + */ + if (gic_data_fiq_enable(gic)) + for (i = 32; i < gic_irqs; i += 32) + writel_relaxed(0xffffffff, + base + GIC_DIST_IGROUP + i * 4 / 32); + + /* + * Set EnableGrp1/EnableGrp0 (bit 1 and 0) or EnableGrp (bit 0 only, + * bit 1 ignored) + */ + if (gic_data_fiq_enable(gic)) + writel_relaxed(3, base + GIC_DIST_CTRL); + else + writel_relaxed(1, base + GIC_DIST_CTRL); } static void gic_cpu_init(struct gic_chip_data *gic) @@ -400,8 +467,20 @@ static void gic_cpu_init(struct gic_chip_data *gic) gic_cpu_config(dist_base, NULL); + /* + * Set all PPI and SGI interrupts to be group 1. + * + * If grouping is not available (not implemented or prohibited by + * security mode) these registers are read-as-zero/write-ignored. + */ + if (gic_data_fiq_enable(gic)) + writel_relaxed(0xffffffff, dist_base + GIC_DIST_IGROUP + 0); + writel_relaxed(0xf0, base + GIC_CPU_PRIMASK); - writel_relaxed(1, base + GIC_CPU_CTRL); + if (gic_data_fiq_enable(gic)) + writel_relaxed(0x1f, base + GIC_CPU_CTRL); + else + writel_relaxed(1, base + GIC_CPU_CTRL); } void gic_cpu_if_down(void) @@ -485,7 +564,10 @@ static void gic_dist_restore(unsigned int gic_nr) writel_relaxed(gic_data[gic_nr].saved_spi_enable[i], dist_base + GIC_DIST_ENABLE_SET + i * 4); - writel_relaxed(1, dist_base + GIC_DIST_CTRL); + if (gic_data_fiq_enable(&gic_data[gic_nr])) + writel_relaxed(3, dist_base + GIC_DIST_CTRL); + else + writel_relaxed(1, dist_base + GIC_DIST_CTRL); } static void gic_cpu_save(unsigned int gic_nr) @@ -542,7 +624,7 @@ static void gic_cpu_restore(unsigned int gic_nr) writel_relaxed(0xa0a0a0a0, dist_base + GIC_DIST_PRI + i * 4); writel_relaxed(0xf0, cpu_base + GIC_CPU_PRIMASK); - writel_relaxed(1, cpu_base + GIC_CPU_CTRL); + writel_relaxed(0x1f, cpu_base + GIC_CPU_CTRL); } static int gic_notifier(struct notifier_block *self, unsigned long cmd, void *v) @@ -604,6 +686,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) { int cpu; unsigned long flags, map = 0; + unsigned long softint; raw_spin_lock_irqsave(&irq_controller_lock, flags); @@ -618,7 +701,11 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) dmb(ishst); /* this always happens on GIC0 */ - writel_relaxed(map << 16 | irq, gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT); + softint = map << 16 | irq; + if (gic_data_fiq_enable(&gic_data[0])) + softint |= 0x8000; + writel_relaxed(softint, + gic_data_dist_base(&gic_data[0]) + GIC_DIST_SOFTINT); raw_spin_unlock_irqrestore(&irq_controller_lock, flags); } @@ -964,6 +1051,8 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base, hwirq_base, &gic_irq_domain_ops, gic); + + gic_init_fiq(gic, irq_base, gic_irqs); } else { gic->domain = irq_domain_add_linear(node, nr_routable_irqs, &gic_irq_domain_ops,