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 #include <asm/uv/uv_irq.h>
  14
  15 static void uv_noop(unsigned int irq)
  16 {
  17 }
  18
  19 static unsigned int uv_noop_ret(unsigned int irq)
  20 {
  21         return 0;
  22 }
  23
  24 static void uv_ack_apic(unsigned int irq)
  25 {
  26         ack_APIC_irq();
  27 }
  28
  29 struct irq_chip uv_irq_chip = {
  30         .name           = "UV-CORE",
  31         .startup        = uv_noop_ret,
  32         .shutdown       = uv_noop,
  33         .enable         = uv_noop,
  34         .disable        = uv_noop,
  35         .ack            = uv_noop,
  36         .mask           = uv_noop,
  37         .unmask         = uv_noop,
  38         .eoi            = uv_ack_apic,
  39         .end            = uv_noop,
  40 };
  41
  42 /*
  43  * Set up a mapping of an available irq and vector, and enable the specified
  44  * MMR that defines the MSI that is to be sent to the specified CPU when an
  45  * interrupt is raised.
  46  */
  47 int uv_setup_irq(char *irq_name, int cpu, int mmr_blade,
  48                  unsigned long mmr_offset)
  49 {
  50         int irq;
  51         int ret;
  52
  53         irq = create_irq();
  54         if (irq <= 0)
  55                 return -EBUSY;
  56
  57         ret = arch_enable_uv_irq(irq_name, irq, cpu, mmr_blade, mmr_offset);
  58         if (ret != irq)
  59                 destroy_irq(irq);
  60
  61         return ret;
  62 }
  63 EXPORT_SYMBOL_GPL(uv_setup_irq);
  64
  65 /*
  66  * Tear down a mapping of an irq and vector, and disable the specified MMR that
  67  * defined the MSI that was to be sent to the specified CPU when an interrupt
  68  * was raised.
  69  *
  70  * Set mmr_blade and mmr_offset to what was passed in on uv_setup_irq().
  71  */
  72 void uv_teardown_irq(unsigned int irq, int mmr_blade, unsigned long mmr_offset)
  73 {
  74         arch_disable_uv_irq(mmr_blade, mmr_offset);
  75         destroy_irq(irq);
  76 }
  77 EXPORT_SYMBOL_GPL(uv_teardown_irq);