arch/x86/kernel/uv_irq.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * SGI UV IRQ functions
   7  *
   8  * Copyright (C) 2008 Silicon Graphics, Inc. All rights reserved.
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/irq.h>
  13
  14 #include <asm/apic.h>
  15 #include <asm/uv/uv_irq.h>
  16
  17 static void uv_noop(unsigned int irq)
  18 {
  19 }
  20
  21 static unsigned int uv_noop_ret(unsigned int irq)
  22 {
  23         return 0;
  24 }
  25
  26 static void uv_ack_apic(unsigned int irq)
  27 {
  28         ack_APIC_irq();
  29 }
  30
  31 struct irq_chip uv_irq_chip = {
  32         .name           = "UV-CORE",
  33         .startup        = uv_noop_ret,
  34         .shutdown       = uv_noop,
  35         .enable         = uv_noop,
  36         .disable        = uv_noop,
  37         .ack            = uv_noop,
  38         .mask           = uv_noop,
  39         .unmask         = uv_noop,
  40         .eoi            = uv_ack_apic,
  41         .end            = uv_noop,
  42 };
  43
  44 /*
  45  * Set up a mapping of an available irq and vector, and enable the specified
  46  * MMR that defines the MSI that is to be sent to the specified CPU when an
  47  * interrupt is raised.
  48  */
  49 int uv_setup_irq(char *irq_name, int cpu, int mmr_blade,
  50                  unsigned long mmr_offset)
  51 {
  52         int irq;
  53         int ret;
  54
  55         irq = create_irq();
  56         if (irq <= 0)
  57                 return -EBUSY;
  58
  59         ret = arch_enable_uv_irq(irq_name, irq, cpu, mmr_blade, mmr_offset);
  60         if (ret != irq)
  61                 destroy_irq(irq);
  62
  63         return ret;
  64 }
  65 EXPORT_SYMBOL_GPL(uv_setup_irq);
  66
  67 /*
  68  * Tear down a mapping of an irq and vector, and disable the specified MMR that
  69  * defined the MSI that was to be sent to the specified CPU when an interrupt
  70  * was raised.
  71  *
  72  * Set mmr_blade and mmr_offset to what was passed in on uv_setup_irq().
  73  */
  74 void uv_teardown_irq(unsigned int irq, int mmr_blade, unsigned long mmr_offset)
  75 {
  76         arch_disable_uv_irq(mmr_blade, mmr_offset);
  77         destroy_irq(irq);
  78 }
  79 EXPORT_SYMBOL_GPL(uv_teardown_irq);