Commit 2b75c0f9 authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: [SMP] unify cpu private IRQ requests (TIMER/IPI) 



The current cpu-private IRQ registration is ugly as it requires need to
expose arch_unmask_irq() outside of intc code.
So switch to percpu IRQ APIs:
  -request_percpu_irq [boot core]
  -enable_percpu_irq  [all cores]

Encapsulated in helper arc_request_percpu_irq()

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 4c834452

arch/arc/include/asm/irq.h

+4 −0
Original line number Diff line number Diff line
@@ -16,9 +16,13 @@ 
#define TIMER0_IRQ      3

#define TIMER1_IRQ      4



#include <linux/interrupt.h>

#include <asm-generic/irq.h>



extern void arc_init_IRQ(void);

void arc_local_timer_setup(void);

void arc_request_percpu_irq(int irq, int cpu,

                            irqreturn_t (*isr)(int irq, void *dev),

                            const char *irq_nm, void *percpu_dev);



#endif

arch/arc/kernel/irq.c

+26 −0
Original line number Diff line number Diff line
@@ -150,6 +150,32 @@ void arch_do_IRQ(unsigned int irq, struct pt_regs *regs) 
	set_irq_regs(old_regs);

}



void arc_request_percpu_irq(int irq, int cpu,

                            irqreturn_t (*isr)(int irq, void *dev),

                            const char *irq_nm,

                            void *percpu_dev)

{

	/* Boot cpu calls request, all call enable */

	if (!cpu) {

		int rc;



		/*

		 * These 2 calls are essential to making percpu IRQ APIs work

		 * Ideally these details could be hidden in irq chip map function

		 * but the issue is IPIs IRQs being static (non-DT) and platform

		 * specific, so we can't identify them there.

		 */

		irq_set_percpu_devid(irq);

		irq_modify_status(irq, IRQ_NOAUTOEN, 0);  /* @irq, @clr, @set */



		rc = request_percpu_irq(irq, isr, irq_nm, percpu_dev);

		if (rc)

			panic("Percpu IRQ request failed for %d\n", irq);

	}



	enable_percpu_irq(irq, 0);

}



/*

 * arch_local_irq_enable - Enable interrupts.

 *

arch/arc/kernel/smp.c

+4 −11
Original line number Diff line number Diff line
@@ -136,7 +136,7 @@ void start_kernel_secondary(void) 
	pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);



	if (machine_desc->init_smp)

		machine_desc->init_smp(smp_processor_id());

		machine_desc->init_smp(cpu);



	arc_local_timer_setup();
@@ -338,18 +338,11 @@ irqreturn_t do_IPI(int irq, void *dev_id) 
 */

static DEFINE_PER_CPU(int, ipi_dev);



static struct irqaction arc_ipi_irq = {

        .name    = "IPI Interrupt",

        .flags   = IRQF_PERCPU,

        .handler = do_IPI,

};



int smp_ipi_irq_setup(int cpu, int irq)

{

	if (!cpu)

		return setup_irq(irq, &arc_ipi_irq);

	else

		arch_unmask_irq(irq);

	int *dev = per_cpu_ptr(&ipi_dev, cpu);



	arc_request_percpu_irq(irq, cpu, do_IPI, "IPI Interrupt", dev);



	return 0;

}

arch/arc/kernel/time.c

+3 −15
Original line number Diff line number Diff line
@@ -210,12 +210,6 @@ static irqreturn_t timer_irq_handler(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



static struct irqaction arc_timer_irq = {

	.name    = "Timer0 (clock-evt-dev)",

	.flags   = IRQF_TIMER | IRQF_PERCPU,

	.handler = timer_irq_handler,

};



/*

 * Setup the local event timer for @cpu

 */
@@ -228,15 +222,9 @@ void arc_local_timer_setup() 
	clockevents_config_and_register(evt, arc_get_core_freq(),

					0, ARC_TIMER_MAX);



	/*

	 * setup the per-cpu timer IRQ handler - for all cpus

	 * For non boot CPU explicitly unmask at intc

	 * setup_irq() -> .. -> irq_startup() already does this on boot-cpu

	 */

	if (!cpu)

		setup_irq(TIMER0_IRQ, &arc_timer_irq);

	else

		arch_unmask_irq(TIMER0_IRQ);

	/* setup the per-cpu timer IRQ handler - for all cpus */

	arc_request_percpu_irq(TIMER0_IRQ, cpu, timer_irq_handler,

			       "Timer0 (per-cpu-tick)", evt);

}



/*

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