apic.c

   1 /*
   2  * apic.c
   3  *
   4  *      Check for APIC support and initialize external interrupts to use it.
   5  */
   6
   7 #include <marmot.h>
   8
   9 Bool usingAPIC;
  10
  11 void
  12 InitPIC(void)
  13 {
  14    usingAPIC = FALSE;
  15 }
  16
  17 VA apicBase, ioapicBase;
  18
  19 /* uint64 tval, tval2; */
  20
  21 void
  22 InitAPIC(void)
  23 {
  24    uint64 apicBaseReg;
  25    char deviceName[] = {'l', 'a', 'p', 'i', 'c', 0, 0, 0, 0};
  26
  27    if (!CPU_GetFeature(CPU_APIC_ENABLED)) {
  28       InitPIC();
  29       return;
  30    }
  31
  32    usingAPIC = TRUE;
  33
  34    rdmsr(APIC_BASE_MSR, apicBaseReg);
  35 /*    VPROBE_TEST(APIC_BASE_MSR, apicBaseReg); */
  36
  37    apicBase = (VA)(apicBaseReg & 0x000ffffffffff000);
  38    if (apicBase & (1 << 8)) {
  39       deviceName[5] = 'B';
  40       deviceName[6] = 'S';
  41       deviceName[7] = 'P';
  42    } else {
  43       deviceName[5] = 'A';
  44       deviceName[6] = 'P';
  45    }
  46
  47    MapIORegion((PA)apicBase, (PA)apicBase + PAGE_SIZE, deviceName);
  48
  49    /* init IO APIC (part of chipset) */
  50    ioapicBase = (VA)0xfec00000; // real address is in APICBASE on chipset
  51
  52
  53 }