arch/alpha/kernel/irq_srm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Handle interrupts from the SRM, assuming no additional weirdness.
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/sched.h>
   8 #include <linux/irq.h>
   9
  10 #include "proto.h"
  11 #include "irq_impl.h"
  12
  13
  14 /*
  15  * Is the palcode SMP safe? In other words: can we call cserve_ena/dis
  16  * at the same time in multiple CPUs? To be safe I added a spinlock
  17  * but it can be removed trivially if the palcode is robust against smp.
  18  */
  19 DEFINE_SPINLOCK(srm_irq_lock);
  20
  21 static inline void
  22 srm_enable_irq(struct irq_data *d)
  23 {
  24         spin_lock(&srm_irq_lock);
  25         cserve_ena(d->irq - 16);
  26         spin_unlock(&srm_irq_lock);
  27 }
  28
  29 static void
  30 srm_disable_irq(struct irq_data *d)
  31 {
  32         spin_lock(&srm_irq_lock);
  33         cserve_dis(d->irq - 16);
  34         spin_unlock(&srm_irq_lock);
  35 }
  36
  37 /* Handle interrupts from the SRM, assuming no additional weirdness.  */
  38 static struct irq_chip srm_irq_type = {
  39         .name           = "SRM",
  40         .irq_unmask     = srm_enable_irq,
  41         .irq_mask       = srm_disable_irq,
  42         .irq_mask_ack   = srm_disable_irq,
  43 };
  44
  45 void __init
  46 init_srm_irqs(long max, unsigned long ignore_mask)
  47 {
  48         long i;
  49
  50         if (NR_IRQS <= 16)
  51                 return;
  52         for (i = 16; i < max; ++i) {
  53                 if (i < 64 && ((ignore_mask >> i) & 1))
  54                         continue;
  55                 irq_set_chip_and_handler(i, &srm_irq_type, handle_level_irq);
  56                 irq_set_status_flags(i, IRQ_LEVEL);
  57         }
  58 }
  59
  60 void
  61 srm_device_interrupt(unsigned long vector)
  62 {
  63         int irq = (vector - 0x800) >> 4;
  64         handle_irq(irq);
  65 }