irqchip/mips-gic: Fix local interrupts
Since the device hierarchy domain was added by commit c98c1822 ("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 c98c1822 ("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: c98c1822 ("irqchip/mips-gic: Add device hierarchy domain") Signed-off-by:Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Jason Cooper <jason@lakedaemon.net> Cc: Qais Yousef <qsyousef@gmail.com> Cc: stable@vger.kernel.org Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/20160913165335.31389-1-paul.burton@imgtec.comSigned-off-by:
Thomas Gleixner <tglx@linutronix.de>
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