Provide a way to set a GICv3 interrupt as pseudo-NMI. The interrupt must not be enabled when setting/clearing the NMI status of the interrupt.
Signed-off-by: Julien Thierry <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Jason Cooper <[email protected]> Cc: Marc Zyngier <[email protected]> --- drivers/irqchip/irq-gic-v3.c | 54 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/interrupt.h | 1 + 2 files changed, 55 insertions(+) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index fa23d12..cea1000 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -305,6 +305,43 @@ static void handle_percpu_devid_nmi(struct irq_desc *desc) chip->irq_eoi(&desc->irq_data); } +static int gic_irq_set_irqchip_prio(struct irq_data *d, bool val) +{ + u8 prio; + irq_flow_handler_t handler; + + if (gic_peek_irq(d, GICD_ISENABLER)) { + pr_err("Cannot set NMI property of enabled IRQ %u\n", d->irq); + return -EPERM; + } + + if (val) { + prio = GICD_INT_NMI_PRI; + + if (gic_irq(d) < 32) + handler = handle_percpu_devid_nmi; + else + handler = handle_fasteoi_nmi; + } else { + prio = GICD_INT_DEF_PRI; + + if (gic_irq(d) < 32) + handler = handle_percpu_devid_irq; + else + handler = handle_fasteoi_irq; + } + + /* + * Already in a locked context for the desc from calling + * irq_set_irq_chip_state. + * It should be safe to simply modify the handler. + */ + irq_to_desc(d->irq)->handle_irq = handler; + gic_set_irq_prio(gic_irq(d), gic_dist_base(d), prio); + + return 0; +} + static int gic_irq_set_irqchip_state(struct irq_data *d, enum irqchip_irq_state which, bool val) { @@ -326,6 +363,16 @@ static int gic_irq_set_irqchip_state(struct irq_data *d, reg = val ? GICD_ICENABLER : GICD_ISENABLER; break; + case IRQCHIP_STATE_NMI: + if (gic_supports_nmi()) { + return gic_irq_set_irqchip_prio(d, val); + } else if (val) { + pr_warn("Failed to set IRQ %u as NMI, NMIs are unsupported\n", + gic_irq(d)); + return -EINVAL; + } + return 0; + default: return -EINVAL; } @@ -353,6 +400,13 @@ static int gic_irq_get_irqchip_state(struct irq_data *d, *val = !gic_peek_irq(d, GICD_ISENABLER); break; + case IRQCHIP_STATE_NMI: + if (!gic_supports_nmi()) + return -EINVAL; + *val = (gic_get_irq_prio(gic_irq(d), gic_dist_base(d)) == + GICD_INT_NMI_PRI); + break; + default: return -EINVAL; } diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 5426627..02c794f 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -419,6 +419,7 @@ enum irqchip_irq_state { IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */ IRQCHIP_STATE_MASKED, /* Is interrupt masked? */ IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */ + IRQCHIP_STATE_NMI, /* Is IRQ an NMI? */ }; extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, -- 1.9.1
