From caacdbf4aa567ab5e8de1a4070195c5d3e8f1340 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Wed, 7 Mar 2018 15:57:27 -0800 Subject: [PATCH] genirq: Add CONFIG_GENERIC_IRQ_MULTI_HANDLER The arm multi irq handler registration mechanism has been copied into a handful of architectures, including arm64 and openrisc. RISC-V needs the same mechanism. Instead of adding yet another copy for RISC-V copy the arm implementation into the core code depending on a new Kconfig symbol: CONFIG_GENERIC_MULTI_IRQ_HANDLER. Subsequent patches will convert the various architectures. Signed-off-by: Palmer Dabbelt Signed-off-by: Thomas Gleixner Cc: jonas@southpole.se Cc: catalin.marinas@arm.com Cc: Will Deacon Cc: linux@armlinux.org.uk Cc: stefan.kristiansson@saunalahti.fi Cc: openrisc@lists.librecores.org Cc: shorne@gmail.com Cc: linux-riscv@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Link: https://lkml.kernel.org/r/20180307235731.22627-2-palmer@sifive.com --- include/linux/irq.h | 18 ++++++++++++++++++ kernel/irq/Kconfig | 5 +++++ kernel/irq/handle.c | 15 +++++++++++++++ 3 files changed, 38 insertions(+) diff --git a/include/linux/irq.h b/include/linux/irq.h index 979eed1b2654..65916a305f3d 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -1165,4 +1165,22 @@ int __ipi_send_mask(struct irq_desc *desc, const struct cpumask *dest); int ipi_send_single(unsigned int virq, unsigned int cpu); int ipi_send_mask(unsigned int virq, const struct cpumask *dest); +#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER +/* + * Registers a generic IRQ handling function as the top-level IRQ handler in + * the system, which is generally the first C code called from an assembly + * architecture-specific interrupt handler. + * + * Returns 0 on success, or -EBUSY if an IRQ handler has already been + * registered. + */ +int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)); + +/* + * Allows interrupt handlers to find the irqchip that's been registered as the + * top-level IRQ handler. + */ +extern void (*handle_arch_irq)(struct pt_regs *) __ro_after_init; +#endif + #endif /* _LINUX_IRQ_H */ diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig index 6fc87ccda1d7..5f3e2baefca9 100644 --- a/kernel/irq/Kconfig +++ b/kernel/irq/Kconfig @@ -132,3 +132,8 @@ config GENERIC_IRQ_DEBUGFS If you don't know what to do here, say N. endmenu + +config GENERIC_IRQ_MULTI_HANDLER + bool + help + Allow to specify the low level IRQ handler at run time. diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 79f987b942b8..3570c715c3e7 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -20,6 +20,10 @@ #include "internals.h" +#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER +void (*handle_arch_irq)(struct pt_regs *) __ro_after_init; +#endif + /** * handle_bad_irq - handle spurious and unhandled irqs * @desc: description of the interrupt @@ -207,3 +211,14 @@ irqreturn_t handle_irq_event(struct irq_desc *desc) irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); return ret; } + +#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER +int __init set_handle_irq(void (*handle_irq)(struct pt_regs *)) +{ + if (handle_arch_irq) + return -EBUSY; + + handle_arch_irq = handle_irq; + return 0; +} +#endif