2 * Local APIC handling, local APIC timers
4 * (c) 1999, 2000 Ingo Molnar <mingo@redhat.com>
7 * Maciej W. Rozycki : Bits for genuine 82489DX APICs;
8 * thanks to Eric Gilmore
10 * for testing these extensively.
11 * Maciej W. Rozycki : Various updates and fixes.
12 * Mikael Pettersson : Power Management for UP-APIC.
14 * Mikael Pettersson : PM converted to driver model.
17 #include <linux/init.h>
20 #include <linux/delay.h>
21 #include <linux/bootmem.h>
22 #include <linux/smp_lock.h>
23 #include <linux/interrupt.h>
24 #include <linux/mc146818rtc.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/sysdev.h>
27 #include <linux/cpu.h>
28 #include <linux/clockchips.h>
29 #include <linux/acpi_pmtmr.h>
30 #include <linux/module.h>
32 #include <asm/atomic.h>
35 #include <asm/mpspec.h>
37 #include <asm/arch_hooks.h>
39 #include <asm/i8253.h>
43 #include <mach_apic.h>
44 #include <mach_apicdef.h>
52 #if (SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F
53 # error SPURIOUS_APIC_VECTOR definition error
57 * Knob to control our willingness to enable the local APIC.
59 * -1=force-disable, +1=force-enable
61 static int enable_local_apic __initdata = 0;
63 /* Local APIC timer verification ok */
64 static int local_apic_timer_verify_ok;
67 * Debug level, exported for io_apic.c
71 static unsigned int calibration_result;
73 static int lapic_next_event(unsigned long delta,
74 struct clock_event_device *evt);
75 static void lapic_timer_setup(enum clock_event_mode mode,
76 struct clock_event_device *evt);
77 static void lapic_timer_broadcast(cpumask_t mask);
78 static void apic_pm_activate(void);
81 * The local apic timer can be used for any function which is CPU local.
83 static struct clock_event_device lapic_clockevent = {
85 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
86 | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
88 .set_mode = lapic_timer_setup,
89 .set_next_event = lapic_next_event,
90 .broadcast = lapic_timer_broadcast,
94 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
96 /* Local APIC was disabled by the BIOS and enabled by the kernel */
97 static int enabled_via_apicbase;
100 * Get the LAPIC version
102 static inline int lapic_get_version(void)
104 return GET_APIC_VERSION(apic_read(APIC_LVR));
108 * Check, if the APIC is integrated or a seperate chip
110 static inline int lapic_is_integrated(void)
112 return APIC_INTEGRATED(lapic_get_version());
116 * Check, whether this is a modern or a first generation APIC
118 static int modern_apic(void)
120 /* AMD systems use old APIC versions, so check the CPU */
121 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
122 boot_cpu_data.x86 >= 0xf)
124 return lapic_get_version() >= 0x14;
128 * enable_NMI_through_LVT0 - enable NMI through local vector table 0
130 void enable_NMI_through_LVT0 (void * dummy)
132 unsigned int v = APIC_DM_NMI;
134 /* Level triggered for 82489DX */
135 if (!lapic_is_integrated())
136 v |= APIC_LVT_LEVEL_TRIGGER;
137 apic_write_around(APIC_LVT0, v);
141 * get_physical_broadcast - Get number of physical broadcast IDs
143 int get_physical_broadcast(void)
145 return modern_apic() ? 0xff : 0xf;
149 * lapic_get_maxlvt - get the maximum number of local vector table entries
151 int lapic_get_maxlvt(void)
153 unsigned int v = apic_read(APIC_LVR);
155 /* 82489DXs do not report # of LVT entries. */
156 return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
163 /* Clock divisor is set to 16 */
164 #define APIC_DIVISOR 16
167 * This function sets up the local APIC timer, with a timeout of
168 * 'clocks' APIC bus clock. During calibration we actually call
169 * this function twice on the boot CPU, once with a bogus timeout
170 * value, second time for real. The other (noncalibrating) CPUs
171 * call this function only once, with the real, calibrated value.
173 * We do reads before writes even if unnecessary, to get around the
174 * P5 APIC double write bug.
176 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
178 unsigned int lvtt_value, tmp_value;
180 lvtt_value = LOCAL_TIMER_VECTOR;
182 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
183 if (!lapic_is_integrated())
184 lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
187 lvtt_value |= APIC_LVT_MASKED;
189 apic_write_around(APIC_LVTT, lvtt_value);
194 tmp_value = apic_read(APIC_TDCR);
195 apic_write_around(APIC_TDCR, (tmp_value
196 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
200 apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR);
204 * Program the next event, relative to now
206 static int lapic_next_event(unsigned long delta,
207 struct clock_event_device *evt)
209 apic_write_around(APIC_TMICT, delta);
214 * Setup the lapic timer in periodic or oneshot mode
216 static void lapic_timer_setup(enum clock_event_mode mode,
217 struct clock_event_device *evt)
222 /* Lapic used for broadcast ? */
223 if (!local_apic_timer_verify_ok)
226 local_irq_save(flags);
229 case CLOCK_EVT_MODE_PERIODIC:
230 case CLOCK_EVT_MODE_ONESHOT:
231 __setup_APIC_LVTT(calibration_result,
232 mode != CLOCK_EVT_MODE_PERIODIC, 1);
234 case CLOCK_EVT_MODE_UNUSED:
235 case CLOCK_EVT_MODE_SHUTDOWN:
236 v = apic_read(APIC_LVTT);
237 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
238 apic_write_around(APIC_LVTT, v);
242 local_irq_restore(flags);
246 * Local APIC timer broadcast function
248 static void lapic_timer_broadcast(cpumask_t mask)
251 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
256 * Setup the local APIC timer for this CPU. Copy the initilized values
257 * of the boot CPU and register the clock event in the framework.
259 static void __devinit setup_APIC_timer(void)
261 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
263 memcpy(levt, &lapic_clockevent, sizeof(*levt));
264 levt->cpumask = cpumask_of_cpu(smp_processor_id());
266 clockevents_register_device(levt);
270 * In this functions we calibrate APIC bus clocks to the external timer.
272 * We want to do the calibration only once since we want to have local timer
273 * irqs syncron. CPUs connected by the same APIC bus have the very same bus
276 * This was previously done by reading the PIT/HPET and waiting for a wrap
277 * around to find out, that a tick has elapsed. I have a box, where the PIT
278 * readout is broken, so it never gets out of the wait loop again. This was
279 * also reported by others.
281 * Monitoring the jiffies value is inaccurate and the clockevents
282 * infrastructure allows us to do a simple substitution of the interrupt
285 * The calibration routine also uses the pm_timer when possible, as the PIT
286 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
287 * back to normal later in the boot process).
290 #define LAPIC_CAL_LOOPS (HZ/10)
292 static __initdata volatile int lapic_cal_loops = -1;
293 static __initdata long lapic_cal_t1, lapic_cal_t2;
294 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
295 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
296 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
299 * Temporary interrupt handler.
301 static void __init lapic_cal_handler(struct clock_event_device *dev)
303 unsigned long long tsc = 0;
304 long tapic = apic_read(APIC_TMCCT);
305 unsigned long pm = acpi_pm_read_early();
310 switch (lapic_cal_loops++) {
312 lapic_cal_t1 = tapic;
313 lapic_cal_tsc1 = tsc;
315 lapic_cal_j1 = jiffies;
318 case LAPIC_CAL_LOOPS:
319 lapic_cal_t2 = tapic;
320 lapic_cal_tsc2 = tsc;
321 if (pm < lapic_cal_pm1)
322 pm += ACPI_PM_OVRRUN;
324 lapic_cal_j2 = jiffies;
330 * Setup the boot APIC
332 * Calibrate and verify the result.
334 void __init setup_boot_APIC_clock(void)
336 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
337 const long pm_100ms = PMTMR_TICKS_PER_SEC/10;
338 const long pm_thresh = pm_100ms/100;
339 void (*real_handler)(struct clock_event_device *dev);
340 unsigned long deltaj;
343 apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
344 "calibrating APIC timer ...\n");
348 /* Replace the global interrupt handler */
349 real_handler = global_clock_event->event_handler;
350 global_clock_event->event_handler = lapic_cal_handler;
353 * Setup the APIC counter to 1e9. There is no way the lapic
354 * can underflow in the 100ms detection time frame
356 __setup_APIC_LVTT(1000000000, 0, 0);
358 /* Let the interrupts run */
361 while(lapic_cal_loops <= LAPIC_CAL_LOOPS);
365 /* Restore the real event handler */
366 global_clock_event->event_handler = real_handler;
368 /* Build delta t1-t2 as apic timer counts down */
369 delta = lapic_cal_t1 - lapic_cal_t2;
370 apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
372 /* Check, if the PM timer is available */
373 deltapm = lapic_cal_pm2 - lapic_cal_pm1;
374 apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm);
380 mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
382 if (deltapm > (pm_100ms - pm_thresh) &&
383 deltapm < (pm_100ms + pm_thresh)) {
384 apic_printk(APIC_VERBOSE, "... PM timer result ok\n");
386 res = (((u64) deltapm) * mult) >> 22;
387 do_div(res, 1000000);
388 printk(KERN_WARNING "APIC calibration not consistent "
389 "with PM Timer: %ldms instead of 100ms\n",
391 /* Correct the lapic counter value */
392 res = (((u64) delta ) * pm_100ms);
393 do_div(res, deltapm);
394 printk(KERN_INFO "APIC delta adjusted to PM-Timer: "
395 "%lu (%ld)\n", (unsigned long) res, delta);
400 /* Calculate the scaled math multiplication factor */
401 lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS, 32);
402 lapic_clockevent.max_delta_ns =
403 clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
404 lapic_clockevent.min_delta_ns =
405 clockevent_delta2ns(0xF, &lapic_clockevent);
407 calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
409 apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
410 apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult);
411 apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
415 delta = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
416 apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
418 (delta / LAPIC_CAL_LOOPS) / (1000000 / HZ),
419 (delta / LAPIC_CAL_LOOPS) % (1000000 / HZ));
422 apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
424 calibration_result / (1000000 / HZ),
425 calibration_result % (1000000 / HZ));
428 apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
431 * Setup the apic timer manually
433 local_apic_timer_verify_ok = 1;
434 levt->event_handler = lapic_cal_handler;
435 lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
436 lapic_cal_loops = -1;
438 /* Let the interrupts run */
441 while(lapic_cal_loops <= LAPIC_CAL_LOOPS);
445 /* Stop the lapic timer */
446 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
451 deltaj = lapic_cal_j2 - lapic_cal_j1;
452 apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
454 /* Check, if the PM timer is available */
455 deltapm = lapic_cal_pm2 - lapic_cal_pm1;
456 apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm);
458 local_apic_timer_verify_ok = 0;
461 if (deltapm > (pm_100ms - pm_thresh) &&
462 deltapm < (pm_100ms + pm_thresh)) {
463 apic_printk(APIC_VERBOSE, "... PM timer result ok\n");
464 /* Check, if the jiffies result is consistent */
465 if (deltaj < LAPIC_CAL_LOOPS-2 ||
466 deltaj > LAPIC_CAL_LOOPS+2) {
468 * Not sure, what we can do about this one.
469 * When high resultion timers are active
470 * and the lapic timer does not stop in C3
471 * we are fine. Otherwise more trouble might
472 * be waiting. -- tglx
474 printk(KERN_WARNING "Global event device %s "
475 "has wrong frequency "
476 "(%lu ticks instead of %d)\n",
477 global_clock_event->name, deltaj,
480 local_apic_timer_verify_ok = 1;
483 /* Check, if the jiffies result is consistent */
484 if (deltaj >= LAPIC_CAL_LOOPS-2 &&
485 deltaj <= LAPIC_CAL_LOOPS+2) {
486 apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
487 local_apic_timer_verify_ok = 1;
491 if (!local_apic_timer_verify_ok) {
493 "APIC timer disabled due to verification failure.\n");
494 /* No broadcast on UP ! */
495 if (num_possible_cpus() == 1)
498 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
500 /* Setup the lapic or request the broadcast */
504 void __devinit setup_secondary_APIC_clock(void)
510 * The guts of the apic timer interrupt
512 static void local_apic_timer_interrupt(void)
514 int cpu = smp_processor_id();
515 struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
518 * Normally we should not be here till LAPIC has been initialized but
519 * in some cases like kdump, its possible that there is a pending LAPIC
520 * timer interrupt from previous kernel's context and is delivered in
521 * new kernel the moment interrupts are enabled.
523 * Interrupts are enabled early and LAPIC is setup much later, hence
524 * its possible that when we get here evt->event_handler is NULL.
525 * Check for event_handler being NULL and discard the interrupt as
528 if (!evt->event_handler) {
530 "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
532 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
536 per_cpu(irq_stat, cpu).apic_timer_irqs++;
538 evt->event_handler(evt);
542 * Local APIC timer interrupt. This is the most natural way for doing
543 * local interrupts, but local timer interrupts can be emulated by
544 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
546 * [ if a single-CPU system runs an SMP kernel then we call the local
547 * interrupt as well. Thus we cannot inline the local irq ... ]
550 void fastcall smp_apic_timer_interrupt(struct pt_regs *regs)
552 struct pt_regs *old_regs = set_irq_regs(regs);
555 * NOTE! We'd better ACK the irq immediately,
556 * because timer handling can be slow.
560 * update_process_times() expects us to have done irq_enter().
561 * Besides, if we don't timer interrupts ignore the global
562 * interrupt lock, which is the WrongThing (tm) to do.
566 local_apic_timer_interrupt();
569 set_irq_regs(old_regs);
572 int setup_profiling_timer(unsigned int multiplier)
578 * Local APIC start and shutdown
582 * clear_local_APIC - shutdown the local APIC
584 * This is called, when a CPU is disabled and before rebooting, so the state of
585 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
586 * leftovers during boot.
588 void clear_local_APIC(void)
590 int maxlvt = lapic_get_maxlvt();
594 * Masking an LVT entry can trigger a local APIC error
595 * if the vector is zero. Mask LVTERR first to prevent this.
598 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
599 apic_write_around(APIC_LVTERR, v | APIC_LVT_MASKED);
602 * Careful: we have to set masks only first to deassert
603 * any level-triggered sources.
605 v = apic_read(APIC_LVTT);
606 apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
607 v = apic_read(APIC_LVT0);
608 apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
609 v = apic_read(APIC_LVT1);
610 apic_write_around(APIC_LVT1, v | APIC_LVT_MASKED);
612 v = apic_read(APIC_LVTPC);
613 apic_write_around(APIC_LVTPC, v | APIC_LVT_MASKED);
616 /* lets not touch this if we didn't frob it */
617 #ifdef CONFIG_X86_MCE_P4THERMAL
619 v = apic_read(APIC_LVTTHMR);
620 apic_write_around(APIC_LVTTHMR, v | APIC_LVT_MASKED);
624 * Clean APIC state for other OSs:
626 apic_write_around(APIC_LVTT, APIC_LVT_MASKED);
627 apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
628 apic_write_around(APIC_LVT1, APIC_LVT_MASKED);
630 apic_write_around(APIC_LVTERR, APIC_LVT_MASKED);
632 apic_write_around(APIC_LVTPC, APIC_LVT_MASKED);
634 #ifdef CONFIG_X86_MCE_P4THERMAL
636 apic_write_around(APIC_LVTTHMR, APIC_LVT_MASKED);
638 /* Integrated APIC (!82489DX) ? */
639 if (lapic_is_integrated()) {
641 /* Clear ESR due to Pentium errata 3AP and 11AP */
642 apic_write(APIC_ESR, 0);
648 * disable_local_APIC - clear and disable the local APIC
650 void disable_local_APIC(void)
657 * Disable APIC (implies clearing of registers
660 value = apic_read(APIC_SPIV);
661 value &= ~APIC_SPIV_APIC_ENABLED;
662 apic_write_around(APIC_SPIV, value);
665 * When LAPIC was disabled by the BIOS and enabled by the kernel,
666 * restore the disabled state.
668 if (enabled_via_apicbase) {
671 rdmsr(MSR_IA32_APICBASE, l, h);
672 l &= ~MSR_IA32_APICBASE_ENABLE;
673 wrmsr(MSR_IA32_APICBASE, l, h);
678 * If Linux enabled the LAPIC against the BIOS default disable it down before
679 * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and
680 * not power-off. Additionally clear all LVT entries before disable_local_APIC
681 * for the case where Linux didn't enable the LAPIC.
683 void lapic_shutdown(void)
690 local_irq_save(flags);
693 if (enabled_via_apicbase)
694 disable_local_APIC();
696 local_irq_restore(flags);
700 * This is to verify that we're looking at a real local APIC.
701 * Check these against your board if the CPUs aren't getting
702 * started for no apparent reason.
704 int __init verify_local_APIC(void)
706 unsigned int reg0, reg1;
709 * The version register is read-only in a real APIC.
711 reg0 = apic_read(APIC_LVR);
712 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
713 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
714 reg1 = apic_read(APIC_LVR);
715 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
718 * The two version reads above should print the same
719 * numbers. If the second one is different, then we
720 * poke at a non-APIC.
726 * Check if the version looks reasonably.
728 reg1 = GET_APIC_VERSION(reg0);
729 if (reg1 == 0x00 || reg1 == 0xff)
731 reg1 = lapic_get_maxlvt();
732 if (reg1 < 0x02 || reg1 == 0xff)
736 * The ID register is read/write in a real APIC.
738 reg0 = apic_read(APIC_ID);
739 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
742 * The next two are just to see if we have sane values.
743 * They're only really relevant if we're in Virtual Wire
744 * compatibility mode, but most boxes are anymore.
746 reg0 = apic_read(APIC_LVT0);
747 apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
748 reg1 = apic_read(APIC_LVT1);
749 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
755 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
757 void __init sync_Arb_IDs(void)
760 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
768 apic_wait_icr_idle();
770 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
771 apic_write_around(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
776 * An initial setup of the virtual wire mode.
778 void __init init_bsp_APIC(void)
783 * Don't do the setup now if we have a SMP BIOS as the
784 * through-I/O-APIC virtual wire mode might be active.
786 if (smp_found_config || !cpu_has_apic)
790 * Do not trust the local APIC being empty at bootup.
797 value = apic_read(APIC_SPIV);
798 value &= ~APIC_VECTOR_MASK;
799 value |= APIC_SPIV_APIC_ENABLED;
801 /* This bit is reserved on P4/Xeon and should be cleared */
802 if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
803 (boot_cpu_data.x86 == 15))
804 value &= ~APIC_SPIV_FOCUS_DISABLED;
806 value |= APIC_SPIV_FOCUS_DISABLED;
807 value |= SPURIOUS_APIC_VECTOR;
808 apic_write_around(APIC_SPIV, value);
811 * Set up the virtual wire mode.
813 apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
815 if (!lapic_is_integrated()) /* 82489DX */
816 value |= APIC_LVT_LEVEL_TRIGGER;
817 apic_write_around(APIC_LVT1, value);
821 * setup_local_APIC - setup the local APIC
823 void __devinit setup_local_APIC(void)
825 unsigned long oldvalue, value, maxlvt, integrated;
828 /* Pound the ESR really hard over the head with a big hammer - mbligh */
830 apic_write(APIC_ESR, 0);
831 apic_write(APIC_ESR, 0);
832 apic_write(APIC_ESR, 0);
833 apic_write(APIC_ESR, 0);
836 integrated = lapic_is_integrated();
839 * Double-check whether this APIC is really registered.
841 if (!apic_id_registered())
845 * Intel recommends to set DFR, LDR and TPR before enabling
846 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
847 * document number 292116). So here it goes...
852 * Set Task Priority to 'accept all'. We never change this
855 value = apic_read(APIC_TASKPRI);
856 value &= ~APIC_TPRI_MASK;
857 apic_write_around(APIC_TASKPRI, value);
860 * After a crash, we no longer service the interrupts and a pending
861 * interrupt from previous kernel might still have ISR bit set.
863 * Most probably by now CPU has serviced that pending interrupt and
864 * it might not have done the ack_APIC_irq() because it thought,
865 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
866 * does not clear the ISR bit and cpu thinks it has already serivced
867 * the interrupt. Hence a vector might get locked. It was noticed
868 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
870 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
871 value = apic_read(APIC_ISR + i*0x10);
872 for (j = 31; j >= 0; j--) {
879 * Now that we are all set up, enable the APIC
881 value = apic_read(APIC_SPIV);
882 value &= ~APIC_VECTOR_MASK;
886 value |= APIC_SPIV_APIC_ENABLED;
889 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
890 * certain networking cards. If high frequency interrupts are
891 * happening on a particular IOAPIC pin, plus the IOAPIC routing
892 * entry is masked/unmasked at a high rate as well then sooner or
893 * later IOAPIC line gets 'stuck', no more interrupts are received
894 * from the device. If focus CPU is disabled then the hang goes
897 * [ This bug can be reproduced easily with a level-triggered
898 * PCI Ne2000 networking cards and PII/PIII processors, dual
902 * Actually disabling the focus CPU check just makes the hang less
903 * frequent as it makes the interrupt distributon model be more
904 * like LRU than MRU (the short-term load is more even across CPUs).
905 * See also the comment in end_level_ioapic_irq(). --macro
908 /* Enable focus processor (bit==0) */
909 value &= ~APIC_SPIV_FOCUS_DISABLED;
912 * Set spurious IRQ vector
914 value |= SPURIOUS_APIC_VECTOR;
915 apic_write_around(APIC_SPIV, value);
920 * set up through-local-APIC on the BP's LINT0. This is not
921 * strictly necessery in pure symmetric-IO mode, but sometimes
922 * we delegate interrupts to the 8259A.
925 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
927 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
928 if (!smp_processor_id() && (pic_mode || !value)) {
929 value = APIC_DM_EXTINT;
930 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
933 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
934 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
937 apic_write_around(APIC_LVT0, value);
940 * only the BP should see the LINT1 NMI signal, obviously.
942 if (!smp_processor_id())
945 value = APIC_DM_NMI | APIC_LVT_MASKED;
946 if (!integrated) /* 82489DX */
947 value |= APIC_LVT_LEVEL_TRIGGER;
948 apic_write_around(APIC_LVT1, value);
950 if (integrated && !esr_disable) { /* !82489DX */
951 maxlvt = lapic_get_maxlvt();
952 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
953 apic_write(APIC_ESR, 0);
954 oldvalue = apic_read(APIC_ESR);
956 /* enables sending errors */
957 value = ERROR_APIC_VECTOR;
958 apic_write_around(APIC_LVTERR, value);
960 * spec says clear errors after enabling vector.
963 apic_write(APIC_ESR, 0);
964 value = apic_read(APIC_ESR);
965 if (value != oldvalue)
966 apic_printk(APIC_VERBOSE, "ESR value before enabling "
967 "vector: 0x%08lx after: 0x%08lx\n",
972 * Something untraceble is creating bad interrupts on
973 * secondary quads ... for the moment, just leave the
974 * ESR disabled - we can't do anything useful with the
975 * errors anyway - mbligh
977 printk(KERN_INFO "Leaving ESR disabled.\n");
979 printk(KERN_INFO "No ESR for 82489DX.\n");
982 /* Disable the local apic timer */
983 value = apic_read(APIC_LVTT);
984 value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
985 apic_write_around(APIC_LVTT, value);
987 setup_apic_nmi_watchdog(NULL);
992 * Detect and initialize APIC
994 static int __init detect_init_APIC (void)
998 /* Disabled by kernel option? */
999 if (enable_local_apic < 0)
1002 switch (boot_cpu_data.x86_vendor) {
1003 case X86_VENDOR_AMD:
1004 if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1005 (boot_cpu_data.x86 == 15))
1008 case X86_VENDOR_INTEL:
1009 if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1010 (boot_cpu_data.x86 == 5 && cpu_has_apic))
1017 if (!cpu_has_apic) {
1019 * Over-ride BIOS and try to enable the local APIC only if
1020 * "lapic" specified.
1022 if (enable_local_apic <= 0) {
1023 printk(KERN_INFO "Local APIC disabled by BIOS -- "
1024 "you can enable it with \"lapic\"\n");
1028 * Some BIOSes disable the local APIC in the APIC_BASE
1029 * MSR. This can only be done in software for Intel P6 or later
1030 * and AMD K7 (Model > 1) or later.
1032 rdmsr(MSR_IA32_APICBASE, l, h);
1033 if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1035 "Local APIC disabled by BIOS -- reenabling.\n");
1036 l &= ~MSR_IA32_APICBASE_BASE;
1037 l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
1038 wrmsr(MSR_IA32_APICBASE, l, h);
1039 enabled_via_apicbase = 1;
1043 * The APIC feature bit should now be enabled
1046 features = cpuid_edx(1);
1047 if (!(features & (1 << X86_FEATURE_APIC))) {
1048 printk(KERN_WARNING "Could not enable APIC!\n");
1051 set_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1052 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1054 /* The BIOS may have set up the APIC at some other address */
1055 rdmsr(MSR_IA32_APICBASE, l, h);
1056 if (l & MSR_IA32_APICBASE_ENABLE)
1057 mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1059 if (nmi_watchdog != NMI_NONE)
1060 nmi_watchdog = NMI_LOCAL_APIC;
1062 printk(KERN_INFO "Found and enabled local APIC!\n");
1069 printk(KERN_INFO "No local APIC present or hardware disabled\n");
1074 * init_apic_mappings - initialize APIC mappings
1076 void __init init_apic_mappings(void)
1078 unsigned long apic_phys;
1081 * If no local APIC can be found then set up a fake all
1082 * zeroes page to simulate the local APIC and another
1083 * one for the IO-APIC.
1085 if (!smp_found_config && detect_init_APIC()) {
1086 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
1087 apic_phys = __pa(apic_phys);
1089 apic_phys = mp_lapic_addr;
1091 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1092 printk(KERN_DEBUG "mapped APIC to %08lx (%08lx)\n", APIC_BASE,
1096 * Fetch the APIC ID of the BSP in case we have a
1097 * default configuration (or the MP table is broken).
1099 if (boot_cpu_physical_apicid == -1U)
1100 boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
1102 #ifdef CONFIG_X86_IO_APIC
1104 unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
1107 for (i = 0; i < nr_ioapics; i++) {
1108 if (smp_found_config) {
1109 ioapic_phys = mp_ioapics[i].mpc_apicaddr;
1112 "WARNING: bogus zero IO-APIC "
1113 "address found in MPTABLE, "
1114 "disabling IO/APIC support!\n");
1115 smp_found_config = 0;
1116 skip_ioapic_setup = 1;
1117 goto fake_ioapic_page;
1121 ioapic_phys = (unsigned long)
1122 alloc_bootmem_pages(PAGE_SIZE);
1123 ioapic_phys = __pa(ioapic_phys);
1125 set_fixmap_nocache(idx, ioapic_phys);
1126 printk(KERN_DEBUG "mapped IOAPIC to %08lx (%08lx)\n",
1127 __fix_to_virt(idx), ioapic_phys);
1135 * This initializes the IO-APIC and APIC hardware if this is
1138 int __init APIC_init_uniprocessor (void)
1140 if (enable_local_apic < 0)
1141 clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1143 if (!smp_found_config && !cpu_has_apic)
1147 * Complain if the BIOS pretends there is one.
1149 if (!cpu_has_apic &&
1150 APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1151 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
1152 boot_cpu_physical_apicid);
1153 clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1157 verify_local_APIC();
1162 * Hack: In case of kdump, after a crash, kernel might be booting
1163 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1164 * might be zero if read from MP tables. Get it from LAPIC.
1166 #ifdef CONFIG_CRASH_DUMP
1167 boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
1169 phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
1173 #ifdef CONFIG_X86_IO_APIC
1174 if (smp_found_config)
1175 if (!skip_ioapic_setup && nr_ioapics)
1184 * APIC command line parameters
1186 static int __init parse_lapic(char *arg)
1188 enable_local_apic = 1;
1191 early_param("lapic", parse_lapic);
1193 static int __init parse_nolapic(char *arg)
1195 enable_local_apic = -1;
1196 clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1199 early_param("nolapic", parse_nolapic);
1201 static int __init apic_set_verbosity(char *str)
1203 if (strcmp("debug", str) == 0)
1204 apic_verbosity = APIC_DEBUG;
1205 else if (strcmp("verbose", str) == 0)
1206 apic_verbosity = APIC_VERBOSE;
1210 __setup("apic=", apic_set_verbosity);
1214 * Local APIC interrupts
1218 * This interrupt should _never_ happen with our APIC/SMP architecture
1220 void smp_spurious_interrupt(struct pt_regs *regs)
1227 * Check if this really is a spurious interrupt and ACK it
1228 * if it is a vectored one. Just in case...
1229 * Spurious interrupts should not be ACKed.
1231 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1232 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1235 /* see sw-dev-man vol 3, chapter 7.4.13.5 */
1236 printk(KERN_INFO "spurious APIC interrupt on CPU#%d, "
1237 "should never happen.\n", smp_processor_id());
1242 * This interrupt should never happen with our APIC/SMP architecture
1244 void smp_error_interrupt(struct pt_regs *regs)
1246 unsigned long v, v1;
1250 /* First tickle the hardware, only then report what went on. -- REW */
1251 v = apic_read(APIC_ESR);
1252 apic_write(APIC_ESR, 0);
1253 v1 = apic_read(APIC_ESR);
1255 atomic_inc(&irq_err_count);
1257 /* Here is what the APIC error bits mean:
1260 2: Send accept error
1261 3: Receive accept error
1263 5: Send illegal vector
1264 6: Received illegal vector
1265 7: Illegal register address
1267 printk (KERN_DEBUG "APIC error on CPU%d: %02lx(%02lx)\n",
1268 smp_processor_id(), v , v1);
1273 * Initialize APIC interrupts
1275 void __init apic_intr_init(void)
1280 /* self generated IPI for local APIC timer */
1281 set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
1283 /* IPI vectors for APIC spurious and error interrupts */
1284 set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
1285 set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
1287 /* thermal monitor LVT interrupt */
1288 #ifdef CONFIG_X86_MCE_P4THERMAL
1289 set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
1294 * connect_bsp_APIC - attach the APIC to the interrupt system
1296 void __init connect_bsp_APIC(void)
1300 * Do not trust the local APIC being empty at bootup.
1304 * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
1305 * local APIC to INT and NMI lines.
1307 apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1308 "enabling APIC mode.\n");
1316 * disconnect_bsp_APIC - detach the APIC from the interrupt system
1317 * @virt_wire_setup: indicates, whether virtual wire mode is selected
1319 * Virtual wire mode is necessary to deliver legacy interrupts even when the
1322 void disconnect_bsp_APIC(int virt_wire_setup)
1326 * Put the board back into PIC mode (has an effect only on
1327 * certain older boards). Note that APIC interrupts, including
1328 * IPIs, won't work beyond this point! The only exception are
1331 apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1332 "entering PIC mode.\n");
1336 /* Go back to Virtual Wire compatibility mode */
1337 unsigned long value;
1339 /* For the spurious interrupt use vector F, and enable it */
1340 value = apic_read(APIC_SPIV);
1341 value &= ~APIC_VECTOR_MASK;
1342 value |= APIC_SPIV_APIC_ENABLED;
1344 apic_write_around(APIC_SPIV, value);
1346 if (!virt_wire_setup) {
1348 * For LVT0 make it edge triggered, active high,
1349 * external and enabled
1351 value = apic_read(APIC_LVT0);
1352 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1353 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1354 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
1355 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1356 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1357 apic_write_around(APIC_LVT0, value);
1360 apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
1364 * For LVT1 make it edge triggered, active high, nmi and
1367 value = apic_read(APIC_LVT1);
1369 APIC_MODE_MASK | APIC_SEND_PENDING |
1370 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1371 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1372 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1373 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1374 apic_write_around(APIC_LVT1, value);
1385 /* r/w apic fields */
1386 unsigned int apic_id;
1387 unsigned int apic_taskpri;
1388 unsigned int apic_ldr;
1389 unsigned int apic_dfr;
1390 unsigned int apic_spiv;
1391 unsigned int apic_lvtt;
1392 unsigned int apic_lvtpc;
1393 unsigned int apic_lvt0;
1394 unsigned int apic_lvt1;
1395 unsigned int apic_lvterr;
1396 unsigned int apic_tmict;
1397 unsigned int apic_tdcr;
1398 unsigned int apic_thmr;
1401 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1403 unsigned long flags;
1406 if (!apic_pm_state.active)
1409 maxlvt = lapic_get_maxlvt();
1411 apic_pm_state.apic_id = apic_read(APIC_ID);
1412 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1413 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1414 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1415 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
1416 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
1418 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
1419 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
1420 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
1421 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
1422 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
1423 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
1424 #ifdef CONFIG_X86_MCE_P4THERMAL
1426 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
1429 local_irq_save(flags);
1430 disable_local_APIC();
1431 local_irq_restore(flags);
1435 static int lapic_resume(struct sys_device *dev)
1438 unsigned long flags;
1441 if (!apic_pm_state.active)
1444 maxlvt = lapic_get_maxlvt();
1446 local_irq_save(flags);
1449 * Make sure the APICBASE points to the right address
1451 * FIXME! This will be wrong if we ever support suspend on
1452 * SMP! We'll need to do this as part of the CPU restore!
1454 rdmsr(MSR_IA32_APICBASE, l, h);
1455 l &= ~MSR_IA32_APICBASE_BASE;
1456 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
1457 wrmsr(MSR_IA32_APICBASE, l, h);
1459 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
1460 apic_write(APIC_ID, apic_pm_state.apic_id);
1461 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
1462 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
1463 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
1464 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
1465 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
1466 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
1467 #ifdef CONFIG_X86_MCE_P4THERMAL
1469 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
1472 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
1473 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
1474 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
1475 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
1476 apic_write(APIC_ESR, 0);
1477 apic_read(APIC_ESR);
1478 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
1479 apic_write(APIC_ESR, 0);
1480 apic_read(APIC_ESR);
1481 local_irq_restore(flags);
1486 * This device has no shutdown method - fully functioning local APICs
1487 * are needed on every CPU up until machine_halt/restart/poweroff.
1490 static struct sysdev_class lapic_sysclass = {
1491 set_kset_name("lapic"),
1492 .resume = lapic_resume,
1493 .suspend = lapic_suspend,
1496 static struct sys_device device_lapic = {
1498 .cls = &lapic_sysclass,
1501 static void __devinit apic_pm_activate(void)
1503 apic_pm_state.active = 1;
1506 static int __init init_lapic_sysfs(void)
1512 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
1514 error = sysdev_class_register(&lapic_sysclass);
1516 error = sysdev_register(&device_lapic);
1519 device_initcall(init_lapic_sysfs);
1521 #else /* CONFIG_PM */
1523 static void apic_pm_activate(void) { }
1525 #endif /* CONFIG_PM */