From ab8079d0144f7231a2ec0f02903ed2665cf622d3 Mon Sep 17 00:00:00 2001 From: Daniel Thompson Date: Tue, 13 Jan 2015 15:36:56 +0000 Subject: irq: gic: Add support for NMI routing This patch provides an implementation of irq_set_nmi_routing by allowing SPIs to be switched between group 1 (IRQ) and group 0 (FIQ). It also repaces the interface used between the default FIQ handler and the GIC. These extensions are required in order to allow SPIs to be acknowledged and completed. Signed-off-by: Daniel Thompson --- arch/arm/kernel/traps.c | 29 +++++++++++++++---- drivers/irqchip/irq-gic.c | 64 +++++++++++++++++++++++++++++------------ include/linux/irqchip/arm-gic.h | 6 +++- 3 files changed, 74 insertions(+), 25 deletions(-) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 5645f81ac4cc..445fdf26b1af 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -462,6 +463,23 @@ die_sig: arm_notify_die("Oops - undefined instruction", regs, &info, 0, 6); } +int arch_filter_nmi_handler(irq_handler_t handler) +{ + irq_handler_t whitelist[] = { + }; + int i; + + for (i = 0; i < ARRAY_SIZE(whitelist); i++) + if (handler == whitelist[i]) { + pr_debug("%pS accepted for use as NMI handler\n", + handler); + return 0; + } + + pr_err("%pS cannot be used as an NMI handler\n", handler); + return -EPERM; +} + /* * Handle FIQ similarly to NMI on x86 systems. * @@ -478,19 +496,20 @@ asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs) { unsigned int cpu = smp_processor_id(); struct pt_regs *old_regs = set_irq_regs(regs); + enum irqreturn irqret = 0; __inc_irq_stat(cpu, __nmi_count); nmi_enter(); -#ifdef CONFIG_ARM_GIC - gic_handle_fiq_ipi(); -#endif + irqret = gic_handle_fiq(); + + if (irqret == IRQ_NONE) { #ifdef CONFIG_SMP - ipi_cpu_backtrace(regs); + ipi_cpu_backtrace(regs); #endif + } nmi_exit(); - set_irq_regs(old_regs); } diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index c4f4a8827ed8..658c6dd5cf08 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -129,6 +129,9 @@ struct irq_chip gic_arch_extn = { static struct gic_chip_data gic_data[MAX_GIC_NR] __read_mostly; +static int gic_set_group_irq(struct gic_chip_data *gic, unsigned int hwirq, + int group); + #ifdef CONFIG_GIC_NON_BANKED static void __iomem *gic_get_percpu_base(union gic_base *base) { @@ -214,6 +217,18 @@ static void gic_eoi_irq(struct irq_data *d) writel_relaxed(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI); } +static int gic_set_nmi_routing(struct irq_data *d, unsigned int nmi) +{ + struct gic_chip_data *gic = irq_data_get_irq_chip_data(d); + int ret; + + ret = gic_set_group_irq(gic, gic_irq(d), !nmi); + if (ret >= 0) + ret = !ret; + + return ret; +} + static int gic_set_type(struct irq_data *d, unsigned int type) { void __iomem *base = gic_dist_base(d); @@ -346,6 +361,7 @@ static struct irq_chip gic_chip = { .irq_mask = gic_mask_irq, .irq_unmask = gic_unmask_irq, .irq_eoi = gic_eoi_irq, + .irq_set_nmi_routing = gic_set_nmi_routing, .irq_set_type = gic_set_type, .irq_retrigger = gic_retrigger, #ifdef CONFIG_SMP @@ -364,8 +380,8 @@ static struct irq_chip gic_chip = { * If is safe to call this function on systems which do not support * grouping (it will have no effect). */ -static void gic_set_group_irq(struct gic_chip_data *gic, unsigned int hwirq, - int group) +static int gic_set_group_irq(struct gic_chip_data *gic, unsigned int hwirq, + int group) { void __iomem *base = gic_data_dist_base(gic); unsigned int grp_reg = hwirq / 32 * 4; @@ -381,7 +397,7 @@ static void gic_set_group_irq(struct gic_chip_data *gic, unsigned int hwirq, * the EnableGrp1 bit set. */ if (!(GICD_ENABLE_GRP1 & readl_relaxed(base + GIC_DIST_CTRL))) - return; + return -EINVAL; raw_spin_lock(&irq_controller_lock); @@ -403,32 +419,42 @@ static void gic_set_group_irq(struct gic_chip_data *gic, unsigned int hwirq, writel_relaxed(pri_val, base + GIC_DIST_PRI + pri_reg); raw_spin_unlock(&irq_controller_lock); -} + return group; +} -/* - * Fully acknowledge (both ack and eoi) any outstanding FIQ-based IPI, - * otherwise do nothing. - */ -void gic_handle_fiq_ipi(void) +enum irqreturn gic_handle_fiq(void) { struct gic_chip_data *gic = &gic_data[0]; void __iomem *cpu_base = gic_data_cpu_base(gic); - unsigned long irqstat, irqnr; + unsigned long irqstat, hwirq; + unsigned int irq = 0; + + /* + * This function is called unconditionally by the default FIQ + * handler so first we must check that the driver it + * initialized. + */ + if (!gic->gic_irqs) + return IRQ_NONE; if (WARN_ON(!in_nmi())) - return; + return IRQ_NONE; - while ((1u << readl_relaxed(cpu_base + GIC_CPU_HIGHPRI)) & - SMP_IPI_FIQ_MASK) { - irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK); - writel_relaxed(irqstat, cpu_base + GIC_CPU_EOI); + /* read intack with the priority mask set so we only acknowledge FIQs */ + writel_relaxed(GICC_INT_PRI_THRESHOLD >> 1, cpu_base + GIC_CPU_PRIMASK); + irqstat = readl_relaxed(cpu_base + GIC_CPU_INTACK); + writel_relaxed(GICC_INT_PRI_THRESHOLD, cpu_base + GIC_CPU_PRIMASK); - irqnr = irqstat & GICC_IAR_INT_ID_MASK; - WARN_RATELIMIT(irqnr > 16, - "Unexpected irqnr %lu (bad prioritization?)\n", - irqnr); + hwirq = irqstat & GICC_IAR_INT_ID_MASK; + if (likely(hwirq > 15 && hwirq < 1021)) { + irq = irq_find_mapping(gic->domain, hwirq); + handle_nmi_irq(irq); } + + writel_relaxed(irqstat, gic_data_cpu_base(gic) + GIC_CPU_EOI); + + return IRQ_RETVAL(irq); } void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq) diff --git a/include/linux/irqchip/arm-gic.h b/include/linux/irqchip/arm-gic.h index 7690f70049a3..265ea31a5711 100644 --- a/include/linux/irqchip/arm-gic.h +++ b/include/linux/irqchip/arm-gic.h @@ -127,7 +127,11 @@ static inline void __init register_routable_domain_ops gic_routable_irq_domain_ops = ops; } -void gic_handle_fiq_ipi(void); +#ifdef CONFIG_ARM_GIC +enum irqreturn gic_handle_fiq(void); +#else +enum irqreturn gic_handle_fiq(void) { return IRQ_NONE; } +#endif #endif /* __ASSEMBLY */ #endif -- cgit v1.2.3