Commit c5e5ec03 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

genirq: Add fasteoi IPI flow 



For irqchips using the fasteoi flow, IPIs are a bit special.
They need to be EOI'd early (before calling the handler), as
funny things may happen in the handler (they do not necessarily
behave like a normal interrupt).

Reviewed-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent f4d51dff

include/linux/irq.h

+1 −0
Original line number Diff line number Diff line
@@ -634,6 +634,7 @@ static inline int irq_set_parent(int irq, int parent_irq) 
 */

extern void handle_level_irq(struct irq_desc *desc);

extern void handle_fasteoi_irq(struct irq_desc *desc);

extern void handle_percpu_devid_fasteoi_ipi(struct irq_desc *desc);

extern void handle_edge_irq(struct irq_desc *desc);

extern void handle_edge_eoi_irq(struct irq_desc *desc);

extern void handle_simple_irq(struct irq_desc *desc);

kernel/irq/chip.c

+27 −0
Original line number Diff line number Diff line
@@ -944,6 +944,33 @@ void handle_percpu_devid_irq(struct irq_desc *desc) 
		chip->irq_eoi(&desc->irq_data);

}



/**

 * handle_percpu_devid_fasteoi_ipi - Per CPU local IPI handler with per cpu

 *				     dev ids

 * @desc:	the interrupt description structure for this irq

 *

 * The biggest difference with the IRQ version is that the interrupt is

 * EOIed early, as the IPI could result in a context switch, and we need to

 * make sure the IPI can fire again. We also assume that the arch code has

 * registered an action. If not, we are positively doomed.

 */

void handle_percpu_devid_fasteoi_ipi(struct irq_desc *desc)

{

	struct irq_chip *chip = irq_desc_get_chip(desc);

	struct irqaction *action = desc->action;

	unsigned int irq = irq_desc_get_irq(desc);

	irqreturn_t res;



	__kstat_incr_irqs_this_cpu(desc);



	if (chip->irq_eoi)

		chip->irq_eoi(&desc->irq_data);



	trace_irq_handler_entry(irq, action);

	res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id));

	trace_irq_handler_exit(irq, action, res);

}



/**

 * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu

 *				     dev ids

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