linux/arch/arc/kernel/irq.c

94 lines
2.5 KiB
C

/*
* Copyright (C) 2011-12 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/interrupt.h>
#include <linux/irqchip.h>
#include <asm/mach_desc.h>
#include <asm/smp.h>
/*
* Late Interrupt system init called from start_kernel for Boot CPU only
*
* Since slab must already be initialized, platforms can start doing any
* needed request_irq( )s
*/
void __init init_IRQ(void)
{
/*
* process the entire interrupt tree in one go
* Any external intc will be setup provided DT chains them
* properly
*/
irqchip_init();
#ifdef CONFIG_SMP
/* a SMP H/w block could do IPI IRQ request here */
if (plat_smp_ops.init_per_cpu)
plat_smp_ops.init_per_cpu(smp_processor_id());
if (machine_desc->init_per_cpu)
machine_desc->init_per_cpu(smp_processor_id());
#endif
}
/*
* "C" Entry point for any ARC ISR, called from low level vector handler
* @irq is the vector number read from ICAUSE reg of on-chip intc
*/
void arch_do_IRQ(unsigned int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
irq_enter();
generic_handle_irq(irq);
irq_exit();
set_irq_regs(old_regs);
}
/*
* API called for requesting percpu interrupts - called by each CPU
* - For boot CPU, actually request the IRQ with genirq core + enables
* - For subsequent callers only enable called locally
*
* Relies on being called by boot cpu first (i.e. request called ahead) of
* any enable as expected by genirq. Hence Suitable only for TIMER, IPI
* which are guaranteed to be setup on boot core first.
* Late probed peripherals such as perf can't use this as there no guarantee
* of being called on boot CPU first.
*/
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;
#ifdef CONFIG_ISA_ARCOMPACT
/*
* A subsequent request_percpu_irq() fails if percpu_devid is
* not set. That in turns sets NOAUTOEN, meaning each core needs
* to call enable_percpu_irq()
*
* For ARCv2, this is done in irq map function since we know
* which irqs are strictly per cpu
*/
irq_set_percpu_devid(irq);
#endif
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);
}