arch/arc/kernel/irq.c

   1 /*
   2  * Copyright (C) 2011-12 Synopsys, Inc. (www.synopsys.com)
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <linux/interrupt.h>
  11 #include <linux/irqchip.h>
  12 #include <asm/mach_desc.h>
  13
  14 /*
  15  * Late Interrupt system init called from start_kernel for Boot CPU only
  16  *
  17  * Since slab must already be initialized, platforms can start doing any
  18  * needed request_irq( )s
  19  */
  20 void __init init_IRQ(void)
  21 {
  22         /* Any external intc can be setup here */
  23         if (machine_desc->init_irq)
  24                 machine_desc->init_irq();
  25
  26         /* process the entire interrupt tree in one go */
  27         irqchip_init();
  28
  29 #ifdef CONFIG_SMP
  30         /* Master CPU can initialize it's side of IPI */
  31         if (machine_desc->init_smp)
  32                 machine_desc->init_smp(smp_processor_id());
  33 #endif
  34 }
  35
  36 /*
  37  * "C" Entry point for any ARC ISR, called from low level vector handler
  38  * @irq is the vector number read from ICAUSE reg of on-chip intc
  39  */
  40 void arch_do_IRQ(unsigned int irq, struct pt_regs *regs)
  41 {
  42         struct pt_regs *old_regs = set_irq_regs(regs);
  43
  44         irq_enter();
  45         generic_handle_irq(irq);
  46         irq_exit();
  47         set_irq_regs(old_regs);
  48 }
  49
  50 void arc_request_percpu_irq(int irq, int cpu,
  51                             irqreturn_t (*isr)(int irq, void *dev),
  52                             const char *irq_nm,
  53                             void *percpu_dev)
  54 {
  55         /* Boot cpu calls request, all call enable */
  56         if (!cpu) {
  57                 int rc;
  58
  59                 /*
  60                  * These 2 calls are essential to making percpu IRQ APIs work
  61                  * Ideally these details could be hidden in irq chip map function
  62                  * but the issue is IPIs IRQs being static (non-DT) and platform
  63                  * specific, so we can't identify them there.
  64                  */
  65                 irq_set_percpu_devid(irq);
  66                 irq_modify_status(irq, IRQ_NOAUTOEN, 0);  /* @irq, @clr, @set */
  67
  68                 rc = request_percpu_irq(irq, isr, irq_nm, percpu_dev);
  69                 if (rc)
  70                         panic("Percpu IRQ request failed for %d\n", irq);
  71         }
  72
  73         enable_percpu_irq(irq, 0);
  74 }