arch/x86/xen/apic.c

   1 #include <linux/init.h>
   2
   3 #include <asm/x86_init.h>
   4 #include <asm/apic.h>
   5 #include <asm/xen/hypercall.h>
   6
   7 #include <xen/xen.h>
   8 #include <xen/interface/physdev.h>
   9 #include "xen-ops.h"
  10
  11 static unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
  12 {
  13         struct physdev_apic apic_op;
  14         int ret;
  15
  16         apic_op.apic_physbase = mpc_ioapic_addr(apic);
  17         apic_op.reg = reg;
  18         ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
  19         if (!ret)
  20                 return apic_op.value;
  21
  22         /* fallback to return an emulated IO_APIC values */
  23         if (reg == 0x1)
  24                 return 0x00170020;
  25         else if (reg == 0x0)
  26                 return apic << 24;
  27
  28         return 0xfd;
  29 }
  30
  31 void __init xen_init_apic(void)
  32 {
  33         x86_io_apic_ops.read = xen_io_apic_read;
  34 }