From e875bd66dfb68f4e898e9a43ef42858c504a7f23 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 13 Sep 2016 17:53:35 +0100 Subject: [PATCH] irqchip/mips-gic: Fix local interrupts Since the device hierarchy domain was added by commit c98c1822ee13 ("irqchip/mips-gic: Add device hierarchy domain"), GIC local interrupts have been broken. Users attempting to setup a per-cpu local IRQ, for example the GIC timer clock events code in drivers/clocksource/mips-gic-timer.c, the setup_percpu_irq function would refuse with -EINVAL because the GIC irqchip driver never called irq_set_percpu_devid so the IRQ_PER_CPU_DEVID flag was never set for the IRQ. This happens because irq_set_percpu_devid was being called from the gic_irq_domain_map function which is no longer called. Doing only that runs into further problems because gic_dev_domain_alloc set the struct irq_chip for all interrupts, local or shared, to gic_level_irq_controller despite that only being suitable for shared interrupts. The typical outcome of this is that gic_level_irq_controller callback functions are called for local interrupts, and then hwirq number calculations overflow & the driver ends up attempting to access some invalid register with an address calculated from an invalid hwirq number. Best case scenario is that this then leads to a bus error. This is fixed by abstracting the setup of the hwirq & chip to a new function gic_setup_dev_chip which is used by both the root GIC IRQ domain & the device domain. Finally, decoding local interrupts failed because gic_dev_domain_alloc only called irq_domain_alloc_irqs_parent for shared interrupts. Local ones were therefore never associated with hwirqs in the root GIC IRQ domain and the virq in gic_handle_local_int would always be 0. This is fixed by calling irq_domain_alloc_irqs_parent unconditionally & having gic_irq_domain_alloc handle both local & shared interrupts, which is easy due to the aforementioned abstraction of chip setup into gic_setup_dev_chip. This fixes use of the MIPS GIC timer for clock events, which has been broken since c98c1822ee13 ("irqchip/mips-gic: Add device hierarchy domain") but hadn't been noticed due to a silent fallback to the MIPS coprocessor 0 count/compare clock events device. Fixes: c98c1822ee13 ("irqchip/mips-gic: Add device hierarchy domain") Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Cc: Jason Cooper Cc: Qais Yousef Cc: stable@vger.kernel.org Cc: Marc Zyngier Link: http://lkml.kernel.org/r/20160913165335.31389-1-paul.burton@imgtec.com Signed-off-by: Thomas Gleixner --- drivers/irqchip/irq-mips-gic.c | 105 ++++++++++++++++----------------- 1 file changed, 50 insertions(+), 55 deletions(-) diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c index 83f498393a7f..6185696405d5 100644 --- a/drivers/irqchip/irq-mips-gic.c +++ b/drivers/irqchip/irq-mips-gic.c @@ -638,27 +638,6 @@ static int gic_local_irq_domain_map(struct irq_domain *d, unsigned int virq, if (!gic_local_irq_is_routable(intr)) return -EPERM; - /* - * HACK: These are all really percpu interrupts, but the rest - * of the MIPS kernel code does not use the percpu IRQ API for - * the CP0 timer and performance counter interrupts. - */ - switch (intr) { - case GIC_LOCAL_INT_TIMER: - case GIC_LOCAL_INT_PERFCTR: - case GIC_LOCAL_INT_FDC: - irq_set_chip_and_handler(virq, - &gic_all_vpes_local_irq_controller, - handle_percpu_irq); - break; - default: - irq_set_chip_and_handler(virq, - &gic_local_irq_controller, - handle_percpu_devid_irq); - irq_set_percpu_devid(virq); - break; - } - spin_lock_irqsave(&gic_lock, flags); for (i = 0; i < gic_vpes; i++) { u32 val = GIC_MAP_TO_PIN_MSK | gic_cpu_pin; @@ -724,16 +703,42 @@ static int gic_shared_irq_domain_map(struct irq_domain *d, unsigned int virq, return 0; } -static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq, - irq_hw_number_t hw) +static int gic_setup_dev_chip(struct irq_domain *d, unsigned int virq, + unsigned int hwirq) { - if (GIC_HWIRQ_TO_LOCAL(hw) < GIC_NUM_LOCAL_INTRS) - return gic_local_irq_domain_map(d, virq, hw); + struct irq_chip *chip; + int err; + + if (hwirq >= GIC_SHARED_HWIRQ_BASE) { + err = irq_domain_set_hwirq_and_chip(d, virq, hwirq, + &gic_level_irq_controller, + NULL); + } else { + switch (GIC_HWIRQ_TO_LOCAL(hwirq)) { + case GIC_LOCAL_INT_TIMER: + case GIC_LOCAL_INT_PERFCTR: + case GIC_LOCAL_INT_FDC: + /* + * HACK: These are all really percpu interrupts, but + * the rest of the MIPS kernel code does not use the + * percpu IRQ API for them. + */ + chip = &gic_all_vpes_local_irq_controller; + irq_set_handler(virq, handle_percpu_irq); + break; + + default: + chip = &gic_local_irq_controller; + irq_set_handler(virq, handle_percpu_devid_irq); + irq_set_percpu_devid(virq); + break; + } - irq_set_chip_and_handler(virq, &gic_level_irq_controller, - handle_level_irq); + err = irq_domain_set_hwirq_and_chip(d, virq, hwirq, + chip, NULL); + } - return gic_shared_irq_domain_map(d, virq, hw, 0); + return err; } static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq, @@ -744,15 +749,12 @@ static int gic_irq_domain_alloc(struct irq_domain *d, unsigned int virq, int cpu, ret, i; if (spec->type == GIC_DEVICE) { - /* verify that it doesn't conflict with an IPI irq */ - if (test_bit(spec->hwirq, ipi_resrv)) + /* verify that shared irqs don't conflict with an IPI irq */ + if ((spec->hwirq >= GIC_SHARED_HWIRQ_BASE) && + test_bit(GIC_HWIRQ_TO_SHARED(spec->hwirq), ipi_resrv)) return -EBUSY; - hwirq = GIC_SHARED_TO_HWIRQ(spec->hwirq); - - return irq_domain_set_hwirq_and_chip(d, virq, hwirq, - &gic_level_irq_controller, - NULL); + return gic_setup_dev_chip(d, virq, spec->hwirq); } else { base_hwirq = find_first_bit(ipi_resrv, gic_shared_intrs); if (base_hwirq == gic_shared_intrs) { @@ -821,7 +823,6 @@ int gic_irq_domain_match(struct irq_domain *d, struct device_node *node, } static const struct irq_domain_ops gic_irq_domain_ops = { - .map = gic_irq_domain_map, .alloc = gic_irq_domain_alloc, .free = gic_irq_domain_free, .match = gic_irq_domain_match, @@ -852,29 +853,20 @@ static int gic_dev_domain_alloc(struct irq_domain *d, unsigned int virq, struct irq_fwspec *fwspec = arg; struct gic_irq_spec spec = { .type = GIC_DEVICE, - .hwirq = fwspec->param[1], }; int i, ret; - bool is_shared = fwspec->param[0] == GIC_SHARED; - if (is_shared) { - ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &spec); - if (ret) - return ret; - } - - for (i = 0; i < nr_irqs; i++) { - irq_hw_number_t hwirq; + if (fwspec->param[0] == GIC_SHARED) + spec.hwirq = GIC_SHARED_TO_HWIRQ(fwspec->param[1]); + else + spec.hwirq = GIC_LOCAL_TO_HWIRQ(fwspec->param[1]); - if (is_shared) - hwirq = GIC_SHARED_TO_HWIRQ(spec.hwirq + i); - else - hwirq = GIC_LOCAL_TO_HWIRQ(spec.hwirq + i); + ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, &spec); + if (ret) + return ret; - ret = irq_domain_set_hwirq_and_chip(d, virq + i, - hwirq, - &gic_level_irq_controller, - NULL); + for (i = 0; i < nr_irqs; i++) { + ret = gic_setup_dev_chip(d, virq + i, spec.hwirq + i); if (ret) goto error; } @@ -896,7 +888,10 @@ void gic_dev_domain_free(struct irq_domain *d, unsigned int virq, static void gic_dev_domain_activate(struct irq_domain *domain, struct irq_data *d) { - gic_shared_irq_domain_map(domain, d->irq, d->hwirq, 0); + if (GIC_HWIRQ_TO_LOCAL(d->hwirq) < GIC_NUM_LOCAL_INTRS) + gic_local_irq_domain_map(domain, d->irq, d->hwirq); + else + gic_shared_irq_domain_map(domain, d->irq, d->hwirq, 0); } static struct irq_domain_ops gic_dev_domain_ops = { -- 2.39.5