Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756183AbaFYJdA (ORCPT ); Wed, 25 Jun 2014 05:33:00 -0400 Received: from fw-tnat.austin.arm.com ([217.140.110.23]:51348 "EHLO collaborate-mta1.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752199AbaFYJ24 (ORCPT ); Wed, 25 Jun 2014 05:28:56 -0400 From: Marc Zyngier To: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Will Deacon , Catalin Marinas , Thomas Gleixner , eric.auger@linaro.org, Christoffer Dall Subject: [RFC PATCH 3/9] irqchip: GIC: Convert to EOImode == 1 Date: Wed, 25 Jun 2014 10:28:44 +0100 Message-Id: <1403688530-23273-4-git-send-email-marc.zyngier@arm.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1403688530-23273-1-git-send-email-marc.zyngier@arm.com> References: <1403688530-23273-1-git-send-email-marc.zyngier@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org So far, GICv2 has been used in with EOImode == 0. The effect of this mode is to perform the priority drop and the deactivation of the interrupt at the same time. While this works perfectly for Linux (we only have a single priority), it causes issues when an interrupt is forwarded to a guest, and when we want the guest to perform the EOI itself. For this case, the GIC architecture provides EOImode == 1, where: - A write to the EOI register drops the priority of the interrupt and leaves it active. Other interrupts at the same priority level can now be taken, but the active interrupt cannot be taken again - A write to the DIR marks the interrupt as inactive, meaning it can now be taken again. We only enable this feature when booted in HYP mode. Also, as most device trees are broken (they report the CPU interface size to be 4kB, while the GICv2 CPU interface size is 8kB), output a warning if we're booted in HYP mode, and disable the feature. Signed-off-by: Marc Zyngier --- drivers/irqchip/irq-gic.c | 61 +++++++++++++++++++++++++++++++++++++---- include/linux/irqchip/arm-gic.h | 4 +++ 2 files changed, 59 insertions(+), 6 deletions(-) diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 508b815..9295bf2 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -45,6 +45,7 @@ #include #include #include +#include #include "irq-gic-common.h" #include "irqchip.h" @@ -94,6 +95,10 @@ struct irq_chip gic_arch_extn = { .irq_set_wake = NULL, }; +static struct irq_chip *gic_chip; + +static bool supports_deactivate = false; + #ifndef MAX_GIC_NR #define MAX_GIC_NR 1 #endif @@ -185,6 +190,12 @@ static void gic_eoi_irq(struct irq_data *d) writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI); } +static void gic_eoi_dir_irq(struct irq_data *d) +{ + gic_eoi_irq(d); + writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_DEACTIVATE); +} + static int gic_set_type(struct irq_data *d, unsigned int type) { void __iomem *base = gic_dist_base(d); @@ -277,6 +288,7 @@ static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs) } if (irqnr < 16) { writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI); + writel_relaxed(irqstat, cpu_base + GIC_CPU_DEACTIVATE); #ifdef CONFIG_SMP handle_IPI(irqnr, regs); #endif @@ -313,7 +325,7 @@ static void gic_handle_cascade_irq(unsigned int irq, struct irq_desc *desc) chained_irq_exit(chip, desc); } -static struct irq_chip gic_chip = { +static struct irq_chip gicv1_chip = { .name = "GIC", .irq_mask = gic_mask_irq, .irq_unmask = gic_unmask_irq, @@ -326,6 +338,19 @@ static struct irq_chip gic_chip = { .irq_set_wake = gic_set_wake, }; +static struct irq_chip gicv2_chip = { + .name = "GIC", + .irq_mask = gic_mask_irq, + .irq_unmask = gic_unmask_irq, + .irq_eoi = gic_eoi_dir_irq, + .irq_set_type = gic_set_type, + .irq_retrigger = gic_retrigger, +#ifdef CONFIG_SMP + .irq_set_affinity = gic_set_affinity, +#endif + .irq_set_wake = gic_set_wake, +}; + void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq) { if (gic_nr >= MAX_GIC_NR) @@ -377,6 +402,16 @@ static void __init gic_dist_init(struct gic_chip_data *gic) writel_relaxed(1, base + GIC_DIST_CTRL); } +static void gic_cpu_if_up(void) +{ + void __iomem *cpu_base = gic_data_cpu_base(&gic_data[0]); + u32 val = 0; + + if (supports_deactivate) + val = GIC_CPU_CTRL_EOImodeNS; + writel_relaxed(val | 1, cpu_base + GIC_CPU_CTRL); +} + static void gic_cpu_init(struct gic_chip_data *gic) { void __iomem *dist_base = gic_data_dist_base(gic); @@ -402,7 +437,7 @@ static void gic_cpu_init(struct gic_chip_data *gic) gic_cpu_config(dist_base, NULL); writel_relaxed(0xf0, base + GIC_CPU_PRIMASK); - writel_relaxed(1, base + GIC_CPU_CTRL); + gic_cpu_if_up(); } void gic_cpu_if_down(void) @@ -543,7 +578,7 @@ 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); + gic_cpu_if_up(); } static int gic_notifier(struct notifier_block *self, unsigned long cmd, void *v) @@ -770,11 +805,11 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq, { if (hw < 32) { irq_set_percpu_devid(irq); - irq_set_chip_and_handler(irq, &gic_chip, + irq_set_chip_and_handler(irq, gic_chip, handle_percpu_devid_irq); set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN); } else { - irq_set_chip_and_handler(irq, &gic_chip, + irq_set_chip_and_handler(irq, gic_chip, handle_fasteoi_irq); set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); @@ -951,6 +986,11 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */ + if (!supports_deactivate) + gic_chip = &gicv1_chip; + else + gic_chip = &gicv2_chip; + if (of_property_read_u32(node, "arm,routable-irqs", &nr_routable_irqs)) { irq_base = irq_alloc_descs(irq_start, 16, gic_irqs, @@ -980,7 +1020,7 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start, set_handle_irq(gic_handle_irq); } - gic_chip.flags |= gic_arch_extn.flags; + gic_chip->flags |= gic_arch_extn.flags; gic_dist_init(gic); gic_cpu_init(gic); gic_pm_init(gic); @@ -994,6 +1034,7 @@ gic_of_init(struct device_node *node, struct device_node *parent) { void __iomem *cpu_base; void __iomem *dist_base; + struct resource cpu_res; u32 percpu_offset; int irq; @@ -1006,6 +1047,14 @@ gic_of_init(struct device_node *node, struct device_node *parent) cpu_base = of_iomap(node, 1); WARN(!cpu_base, "unable to map gic cpu registers\n"); + of_address_to_resource(node, 1, &cpu_res); + if (is_hyp_mode_available()) { + if (resource_size(&cpu_res) >= SZ_8K) + supports_deactivate = true; + else + pr_warn("GIC: CPU interface size is %x, DT is probably wrong\n", (int)resource_size(&cpu_res)); + } + if (of_property_read_u32(node, "cpu-offset", &percpu_offset)) percpu_offset = 0; diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h index 45e2d8c..ffe3911 100644 --- a/include/linux/irqchip/arm-gic.h +++ b/include/linux/irqchip/arm-gic.h @@ -21,6 +21,10 @@ #define GIC_CPU_ACTIVEPRIO 0xd0 #define GIC_CPU_IDENT 0xfc +#define GIC_CPU_DEACTIVATE 0x1000 + +#define GIC_CPU_CTRL_EOImodeNS (1 << 9) + #define GICC_IAR_INT_ID_MASK 0x3ff #define GIC_DIST_CTRL 0x000 -- 1.8.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/