diff options
| -rw-r--r-- | lapic.c | 45 |
1 files changed, 26 insertions, 19 deletions
@@ -37,6 +37,13 @@ volatile uint *lapic; // Initialized in mp.c +static void +lapicw(int index, int value) +{ + lapic[index] = value; + lapic[ID]; // wait for write to finish, by reading +} + //PAGEBREAK! void lapic_init(int c) @@ -45,43 +52,43 @@ lapic_init(int c) return; // Enable local APIC; set spurious interrupt vector. - lapic[SVR] = ENABLE | (IRQ_OFFSET+IRQ_SPURIOUS); + lapicw(SVR, ENABLE | (IRQ_OFFSET+IRQ_SPURIOUS)); // The timer repeatedly counts down at bus frequency // from lapic[TICR] and then issues an interrupt. // If xv6 cared more about precise timekeeping, // TICR would be calibrated using an external time source. - lapic[TDCR] = X1; - lapic[TIMER] = PERIODIC | (IRQ_OFFSET + IRQ_TIMER); - lapic[TICR] = 10000000; + lapicw(TDCR, X1); + lapicw(TIMER, PERIODIC | (IRQ_OFFSET + IRQ_TIMER)); + lapicw(TICR, 10000000); // Disable logical interrupt lines. - lapic[LINT0] = MASKED; - lapic[LINT1] = MASKED; + lapicw(LINT0, MASKED); + lapicw(LINT1, MASKED); // Disable performance counter overflow interrupts // on machines that provide that interrupt entry. if(((lapic[VER]>>16) & 0xFF) >= 4) - lapic[PCINT] = MASKED; + lapicw(PCINT, MASKED); // Map error interrupt to IRQ_ERROR. - lapic[ERROR] = IRQ_OFFSET+IRQ_ERROR; + lapicw(ERROR, IRQ_OFFSET+IRQ_ERROR); // Clear error status register (requires back-to-back writes). - lapic[ESR] = 0; - lapic[ESR] = 0; + lapicw(ESR, 0); + lapicw(ESR, 0); // Ack any outstanding interrupts. - lapic[EOI] = 0; + lapicw(EOI, 0); // Send an Init Level De-Assert to synchronise arbitration ID's. - lapic[ICRHI] = 0; - lapic[ICRLO] = BCAST | INIT | LEVEL; + lapicw(ICRHI, 0); + lapicw(ICRLO, BCAST | INIT | LEVEL); while(lapic[ICRLO] & DELIVS) ; // Enable interrupts on the APIC (but not on the processor). - lapic[TPR] = 0; + lapicw(TPR, 0); } int @@ -116,7 +123,7 @@ void lapic_eoi(void) { if(lapic) - lapic[EOI] = 0; + lapicw(EOI, 0); } // Spin for a given number of microseconds. @@ -139,16 +146,16 @@ lapic_startap(uchar apicid, uint addr) volatile int j = 0; // Send INIT interrupt to reset other CPU. - lapic[ICRHI] = apicid<<24; - lapic[ICRLO] = INIT | LEVEL; + lapicw(ICRHI, apicid<<24); + lapicw(ICRLO, INIT | LEVEL); microdelay(10); // Send startup IPI (twice!) to enter bootstrap code. // Regular hardware wants it twice, but Bochs complains. // Too bad for Bochs. for(i = 0; i < 2; i++){ - lapic[ICRHI] = apicid<<24; - lapic[ICRLO] = STARTUP | (addr>>12); + lapicw(ICRHI, apicid<<24); + lapicw(ICRLO, STARTUP | (addr>>12)); for(j=0; j<10000; j++); // 200us } } |