2 * Local APIC handling, local APIC timers
4 * (c) 1999, 2000, 2009 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/perf_event.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/mc146818rtc.h>
20 #include <linux/acpi_pmtmr.h>
21 #include <linux/clockchips.h>
22 #include <linux/interrupt.h>
23 #include <linux/bootmem.h>
24 #include <linux/ftrace.h>
25 #include <linux/ioport.h>
26 #include <linux/module.h>
27 #include <linux/syscore_ops.h>
28 #include <linux/delay.h>
29 #include <linux/timex.h>
30 #include <linux/dmar.h>
31 #include <linux/init.h>
32 #include <linux/cpu.h>
33 #include <linux/dmi.h>
34 #include <linux/smp.h>
37 #include <asm/perf_event.h>
38 #include <asm/x86_init.h>
39 #include <asm/pgalloc.h>
40 #include <asm/atomic.h>
41 #include <asm/mpspec.h>
42 #include <asm/i8253.h>
43 #include <asm/i8259.h>
44 #include <asm/proto.h>
46 #include <asm/io_apic.h>
54 #include <asm/hypervisor.h>
56 unsigned int num_processors;
58 unsigned disabled_cpus __cpuinitdata;
60 /* Processor that is doing the boot up */
61 unsigned int boot_cpu_physical_apicid = -1U;
64 * The highest APIC ID seen during enumeration.
66 unsigned int max_physical_apicid;
69 * Bitmask of physically existing CPUs:
71 physid_mask_t phys_cpu_present_map;
74 * Map cpu index to physical APIC ID
76 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
77 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
78 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
79 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
84 * On x86_32, the mapping between cpu and logical apicid may vary
85 * depending on apic in use. The following early percpu variable is
86 * used for the mapping. This is where the behaviors of x86_64 and 32
87 * actually diverge. Let's keep it ugly for now.
89 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
92 * Knob to control our willingness to enable the local APIC.
96 static int force_enable_local_apic __initdata;
98 * APIC command line parameters
100 static int __init parse_lapic(char *arg)
102 force_enable_local_apic = 1;
105 early_param("lapic", parse_lapic);
106 /* Local APIC was disabled by the BIOS and enabled by the kernel */
107 static int enabled_via_apicbase;
110 * Handle interrupt mode configuration register (IMCR).
111 * This register controls whether the interrupt signals
112 * that reach the BSP come from the master PIC or from the
113 * local APIC. Before entering Symmetric I/O Mode, either
114 * the BIOS or the operating system must switch out of
115 * PIC Mode by changing the IMCR.
117 static inline void imcr_pic_to_apic(void)
119 /* select IMCR register */
121 /* NMI and 8259 INTR go through APIC */
125 static inline void imcr_apic_to_pic(void)
127 /* select IMCR register */
129 /* NMI and 8259 INTR go directly to BSP */
135 static int apic_calibrate_pmtmr __initdata;
136 static __init int setup_apicpmtimer(char *s)
138 apic_calibrate_pmtmr = 1;
142 __setup("apicpmtimer", setup_apicpmtimer);
146 #ifdef CONFIG_X86_X2APIC
147 /* x2apic enabled before OS handover */
148 static int x2apic_preenabled;
149 static __init int setup_nox2apic(char *str)
151 if (x2apic_enabled()) {
152 pr_warning("Bios already enabled x2apic, "
153 "can't enforce nox2apic");
157 setup_clear_cpu_cap(X86_FEATURE_X2APIC);
160 early_param("nox2apic", setup_nox2apic);
163 unsigned long mp_lapic_addr;
165 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
166 static int disable_apic_timer __initdata;
167 /* Local APIC timer works in C2 */
168 int local_apic_timer_c2_ok;
169 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
171 int first_system_vector = 0xfe;
174 * Debug level, exported for io_apic.c
176 unsigned int apic_verbosity;
180 /* Have we found an MP table */
181 int smp_found_config;
183 static struct resource lapic_resource = {
184 .name = "Local APIC",
185 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
188 static unsigned int calibration_result;
190 static void apic_pm_activate(void);
192 static unsigned long apic_phys;
195 * Get the LAPIC version
197 static inline int lapic_get_version(void)
199 return GET_APIC_VERSION(apic_read(APIC_LVR));
203 * Check, if the APIC is integrated or a separate chip
205 static inline int lapic_is_integrated(void)
210 return APIC_INTEGRATED(lapic_get_version());
215 * Check, whether this is a modern or a first generation APIC
217 static int modern_apic(void)
219 /* AMD systems use old APIC versions, so check the CPU */
220 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
221 boot_cpu_data.x86 >= 0xf)
223 return lapic_get_version() >= 0x14;
227 * right after this call apic become NOOP driven
228 * so apic->write/read doesn't do anything
230 static void __init apic_disable(void)
232 pr_info("APIC: switched to apic NOOP\n");
236 void native_apic_wait_icr_idle(void)
238 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
242 u32 native_safe_apic_wait_icr_idle(void)
249 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
253 } while (timeout++ < 1000);
258 void native_apic_icr_write(u32 low, u32 id)
260 apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
261 apic_write(APIC_ICR, low);
264 u64 native_apic_icr_read(void)
268 icr2 = apic_read(APIC_ICR2);
269 icr1 = apic_read(APIC_ICR);
271 return icr1 | ((u64)icr2 << 32);
276 * get_physical_broadcast - Get number of physical broadcast IDs
278 int get_physical_broadcast(void)
280 return modern_apic() ? 0xff : 0xf;
285 * lapic_get_maxlvt - get the maximum number of local vector table entries
287 int lapic_get_maxlvt(void)
291 v = apic_read(APIC_LVR);
293 * - we always have APIC integrated on 64bit mode
294 * - 82489DXs do not report # of LVT entries
296 return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
304 #define APIC_DIVISOR 16
307 * This function sets up the local APIC timer, with a timeout of
308 * 'clocks' APIC bus clock. During calibration we actually call
309 * this function twice on the boot CPU, once with a bogus timeout
310 * value, second time for real. The other (noncalibrating) CPUs
311 * call this function only once, with the real, calibrated value.
313 * We do reads before writes even if unnecessary, to get around the
314 * P5 APIC double write bug.
316 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
318 unsigned int lvtt_value, tmp_value;
320 lvtt_value = LOCAL_TIMER_VECTOR;
322 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
323 if (!lapic_is_integrated())
324 lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
327 lvtt_value |= APIC_LVT_MASKED;
329 apic_write(APIC_LVTT, lvtt_value);
334 tmp_value = apic_read(APIC_TDCR);
335 apic_write(APIC_TDCR,
336 (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
340 apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
344 * Setup extended LVT, AMD specific
346 * Software should use the LVT offsets the BIOS provides. The offsets
347 * are determined by the subsystems using it like those for MCE
348 * threshold or IBS. On K8 only offset 0 (APIC500) and MCE interrupts
349 * are supported. Beginning with family 10h at least 4 offsets are
352 * Since the offsets must be consistent for all cores, we keep track
353 * of the LVT offsets in software and reserve the offset for the same
354 * vector also to be used on other cores. An offset is freed by
355 * setting the entry to APIC_EILVT_MASKED.
357 * If the BIOS is right, there should be no conflicts. Otherwise a
358 * "[Firmware Bug]: ..." error message is generated. However, if
359 * software does not properly determines the offsets, it is not
360 * necessarily a BIOS bug.
363 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
365 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
367 return (old & APIC_EILVT_MASKED)
368 || (new == APIC_EILVT_MASKED)
369 || ((new & ~APIC_EILVT_MASKED) == old);
372 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
374 unsigned int rsvd; /* 0: uninitialized */
376 if (offset >= APIC_EILVT_NR_MAX)
379 rsvd = atomic_read(&eilvt_offsets[offset]) & ~APIC_EILVT_MASKED;
382 !eilvt_entry_is_changeable(rsvd, new))
383 /* may not change if vectors are different */
385 rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
386 } while (rsvd != new);
392 * If mask=1, the LVT entry does not generate interrupts while mask=0
393 * enables the vector. See also the BKDGs.
396 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
398 unsigned long reg = APIC_EILVTn(offset);
399 unsigned int new, old, reserved;
401 new = (mask << 16) | (msg_type << 8) | vector;
402 old = apic_read(reg);
403 reserved = reserve_eilvt_offset(offset, new);
405 if (reserved != new) {
406 pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
407 "vector 0x%x, but the register is already in use for "
408 "vector 0x%x on another cpu\n",
409 smp_processor_id(), reg, offset, new, reserved);
413 if (!eilvt_entry_is_changeable(old, new)) {
414 pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
415 "vector 0x%x, but the register is already in use for "
416 "vector 0x%x on this cpu\n",
417 smp_processor_id(), reg, offset, new, old);
421 apic_write(reg, new);
425 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
428 * Program the next event, relative to now
430 static int lapic_next_event(unsigned long delta,
431 struct clock_event_device *evt)
433 apic_write(APIC_TMICT, delta);
438 * Setup the lapic timer in periodic or oneshot mode
440 static void lapic_timer_setup(enum clock_event_mode mode,
441 struct clock_event_device *evt)
446 /* Lapic used as dummy for broadcast ? */
447 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
450 local_irq_save(flags);
453 case CLOCK_EVT_MODE_PERIODIC:
454 case CLOCK_EVT_MODE_ONESHOT:
455 __setup_APIC_LVTT(calibration_result,
456 mode != CLOCK_EVT_MODE_PERIODIC, 1);
458 case CLOCK_EVT_MODE_UNUSED:
459 case CLOCK_EVT_MODE_SHUTDOWN:
460 v = apic_read(APIC_LVTT);
461 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
462 apic_write(APIC_LVTT, v);
463 apic_write(APIC_TMICT, 0);
465 case CLOCK_EVT_MODE_RESUME:
466 /* Nothing to do here */
470 local_irq_restore(flags);
474 * Local APIC timer broadcast function
476 static void lapic_timer_broadcast(const struct cpumask *mask)
479 apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
485 * The local apic timer can be used for any function which is CPU local.
487 static struct clock_event_device lapic_clockevent = {
489 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
490 | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
492 .set_mode = lapic_timer_setup,
493 .set_next_event = lapic_next_event,
494 .broadcast = lapic_timer_broadcast,
498 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
501 * Setup the local APIC timer for this CPU. Copy the initialized values
502 * of the boot CPU and register the clock event in the framework.
504 static void __cpuinit setup_APIC_timer(void)
506 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
508 if (this_cpu_has(X86_FEATURE_ARAT)) {
509 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
510 /* Make LAPIC timer preferrable over percpu HPET */
511 lapic_clockevent.rating = 150;
514 memcpy(levt, &lapic_clockevent, sizeof(*levt));
515 levt->cpumask = cpumask_of(smp_processor_id());
517 clockevents_register_device(levt);
521 * In this functions we calibrate APIC bus clocks to the external timer.
523 * We want to do the calibration only once since we want to have local timer
524 * irqs syncron. CPUs connected by the same APIC bus have the very same bus
527 * This was previously done by reading the PIT/HPET and waiting for a wrap
528 * around to find out, that a tick has elapsed. I have a box, where the PIT
529 * readout is broken, so it never gets out of the wait loop again. This was
530 * also reported by others.
532 * Monitoring the jiffies value is inaccurate and the clockevents
533 * infrastructure allows us to do a simple substitution of the interrupt
536 * The calibration routine also uses the pm_timer when possible, as the PIT
537 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
538 * back to normal later in the boot process).
541 #define LAPIC_CAL_LOOPS (HZ/10)
543 static __initdata int lapic_cal_loops = -1;
544 static __initdata long lapic_cal_t1, lapic_cal_t2;
545 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
546 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
547 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
550 * Temporary interrupt handler.
552 static void __init lapic_cal_handler(struct clock_event_device *dev)
554 unsigned long long tsc = 0;
555 long tapic = apic_read(APIC_TMCCT);
556 unsigned long pm = acpi_pm_read_early();
561 switch (lapic_cal_loops++) {
563 lapic_cal_t1 = tapic;
564 lapic_cal_tsc1 = tsc;
566 lapic_cal_j1 = jiffies;
569 case LAPIC_CAL_LOOPS:
570 lapic_cal_t2 = tapic;
571 lapic_cal_tsc2 = tsc;
572 if (pm < lapic_cal_pm1)
573 pm += ACPI_PM_OVRRUN;
575 lapic_cal_j2 = jiffies;
581 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
583 const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
584 const long pm_thresh = pm_100ms / 100;
588 #ifndef CONFIG_X86_PM_TIMER
592 apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
594 /* Check, if the PM timer is available */
598 mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
600 if (deltapm > (pm_100ms - pm_thresh) &&
601 deltapm < (pm_100ms + pm_thresh)) {
602 apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
606 res = (((u64)deltapm) * mult) >> 22;
607 do_div(res, 1000000);
608 pr_warning("APIC calibration not consistent "
609 "with PM-Timer: %ldms instead of 100ms\n",(long)res);
611 /* Correct the lapic counter value */
612 res = (((u64)(*delta)) * pm_100ms);
613 do_div(res, deltapm);
614 pr_info("APIC delta adjusted to PM-Timer: "
615 "%lu (%ld)\n", (unsigned long)res, *delta);
618 /* Correct the tsc counter value */
620 res = (((u64)(*deltatsc)) * pm_100ms);
621 do_div(res, deltapm);
622 apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
623 "PM-Timer: %lu (%ld)\n",
624 (unsigned long)res, *deltatsc);
625 *deltatsc = (long)res;
631 static int __init calibrate_APIC_clock(void)
633 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
634 void (*real_handler)(struct clock_event_device *dev);
635 unsigned long deltaj;
636 long delta, deltatsc;
637 int pm_referenced = 0;
641 /* Replace the global interrupt handler */
642 real_handler = global_clock_event->event_handler;
643 global_clock_event->event_handler = lapic_cal_handler;
646 * Setup the APIC counter to maximum. There is no way the lapic
647 * can underflow in the 100ms detection time frame
649 __setup_APIC_LVTT(0xffffffff, 0, 0);
651 /* Let the interrupts run */
654 while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
659 /* Restore the real event handler */
660 global_clock_event->event_handler = real_handler;
662 /* Build delta t1-t2 as apic timer counts down */
663 delta = lapic_cal_t1 - lapic_cal_t2;
664 apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
666 deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
668 /* we trust the PM based calibration if possible */
669 pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
672 /* Calculate the scaled math multiplication factor */
673 lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
674 lapic_clockevent.shift);
675 lapic_clockevent.max_delta_ns =
676 clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
677 lapic_clockevent.min_delta_ns =
678 clockevent_delta2ns(0xF, &lapic_clockevent);
680 calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
682 apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
683 apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
684 apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
688 apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
690 (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
691 (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
694 apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
696 calibration_result / (1000000 / HZ),
697 calibration_result % (1000000 / HZ));
700 * Do a sanity check on the APIC calibration result
702 if (calibration_result < (1000000 / HZ)) {
704 pr_warning("APIC frequency too slow, disabling apic timer\n");
708 levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
711 * PM timer calibration failed or not turned on
712 * so lets try APIC timer based calibration
714 if (!pm_referenced) {
715 apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
718 * Setup the apic timer manually
720 levt->event_handler = lapic_cal_handler;
721 lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
722 lapic_cal_loops = -1;
724 /* Let the interrupts run */
727 while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
730 /* Stop the lapic timer */
731 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
734 deltaj = lapic_cal_j2 - lapic_cal_j1;
735 apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
737 /* Check, if the jiffies result is consistent */
738 if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
739 apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
741 levt->features |= CLOCK_EVT_FEAT_DUMMY;
745 if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
746 pr_warning("APIC timer disabled due to verification failure\n");
754 * Setup the boot APIC
756 * Calibrate and verify the result.
758 void __init setup_boot_APIC_clock(void)
761 * The local apic timer can be disabled via the kernel
762 * commandline or from the CPU detection code. Register the lapic
763 * timer as a dummy clock event source on SMP systems, so the
764 * broadcast mechanism is used. On UP systems simply ignore it.
766 if (disable_apic_timer) {
767 pr_info("Disabling APIC timer\n");
768 /* No broadcast on UP ! */
769 if (num_possible_cpus() > 1) {
770 lapic_clockevent.mult = 1;
776 apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
777 "calibrating APIC timer ...\n");
779 if (calibrate_APIC_clock()) {
780 /* No broadcast on UP ! */
781 if (num_possible_cpus() > 1)
787 * If nmi_watchdog is set to IO_APIC, we need the
788 * PIT/HPET going. Otherwise register lapic as a dummy
791 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
793 /* Setup the lapic or request the broadcast */
797 void __cpuinit setup_secondary_APIC_clock(void)
803 * The guts of the apic timer interrupt
805 static void local_apic_timer_interrupt(void)
807 int cpu = smp_processor_id();
808 struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
811 * Normally we should not be here till LAPIC has been initialized but
812 * in some cases like kdump, its possible that there is a pending LAPIC
813 * timer interrupt from previous kernel's context and is delivered in
814 * new kernel the moment interrupts are enabled.
816 * Interrupts are enabled early and LAPIC is setup much later, hence
817 * its possible that when we get here evt->event_handler is NULL.
818 * Check for event_handler being NULL and discard the interrupt as
821 if (!evt->event_handler) {
822 pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
824 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
829 * the NMI deadlock-detector uses this.
831 inc_irq_stat(apic_timer_irqs);
833 evt->event_handler(evt);
837 * Local APIC timer interrupt. This is the most natural way for doing
838 * local interrupts, but local timer interrupts can be emulated by
839 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
841 * [ if a single-CPU system runs an SMP kernel then we call the local
842 * interrupt as well. Thus we cannot inline the local irq ... ]
844 void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
846 struct pt_regs *old_regs = set_irq_regs(regs);
849 * NOTE! We'd better ACK the irq immediately,
850 * because timer handling can be slow.
854 * update_process_times() expects us to have done irq_enter().
855 * Besides, if we don't timer interrupts ignore the global
856 * interrupt lock, which is the WrongThing (tm) to do.
860 local_apic_timer_interrupt();
863 set_irq_regs(old_regs);
866 int setup_profiling_timer(unsigned int multiplier)
872 * Local APIC start and shutdown
876 * clear_local_APIC - shutdown the local APIC
878 * This is called, when a CPU is disabled and before rebooting, so the state of
879 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
880 * leftovers during boot.
882 void clear_local_APIC(void)
887 /* APIC hasn't been mapped yet */
888 if (!x2apic_mode && !apic_phys)
891 maxlvt = lapic_get_maxlvt();
893 * Masking an LVT entry can trigger a local APIC error
894 * if the vector is zero. Mask LVTERR first to prevent this.
897 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
898 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
901 * Careful: we have to set masks only first to deassert
902 * any level-triggered sources.
904 v = apic_read(APIC_LVTT);
905 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
906 v = apic_read(APIC_LVT0);
907 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
908 v = apic_read(APIC_LVT1);
909 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
911 v = apic_read(APIC_LVTPC);
912 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
915 /* lets not touch this if we didn't frob it */
916 #ifdef CONFIG_X86_THERMAL_VECTOR
918 v = apic_read(APIC_LVTTHMR);
919 apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
922 #ifdef CONFIG_X86_MCE_INTEL
924 v = apic_read(APIC_LVTCMCI);
925 if (!(v & APIC_LVT_MASKED))
926 apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
931 * Clean APIC state for other OSs:
933 apic_write(APIC_LVTT, APIC_LVT_MASKED);
934 apic_write(APIC_LVT0, APIC_LVT_MASKED);
935 apic_write(APIC_LVT1, APIC_LVT_MASKED);
937 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
939 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
941 /* Integrated APIC (!82489DX) ? */
942 if (lapic_is_integrated()) {
944 /* Clear ESR due to Pentium errata 3AP and 11AP */
945 apic_write(APIC_ESR, 0);
951 * disable_local_APIC - clear and disable the local APIC
953 void disable_local_APIC(void)
957 /* APIC hasn't been mapped yet */
958 if (!x2apic_mode && !apic_phys)
964 * Disable APIC (implies clearing of registers
967 value = apic_read(APIC_SPIV);
968 value &= ~APIC_SPIV_APIC_ENABLED;
969 apic_write(APIC_SPIV, value);
973 * When LAPIC was disabled by the BIOS and enabled by the kernel,
974 * restore the disabled state.
976 if (enabled_via_apicbase) {
979 rdmsr(MSR_IA32_APICBASE, l, h);
980 l &= ~MSR_IA32_APICBASE_ENABLE;
981 wrmsr(MSR_IA32_APICBASE, l, h);
987 * If Linux enabled the LAPIC against the BIOS default disable it down before
988 * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and
989 * not power-off. Additionally clear all LVT entries before disable_local_APIC
990 * for the case where Linux didn't enable the LAPIC.
992 void lapic_shutdown(void)
996 if (!cpu_has_apic && !apic_from_smp_config())
999 local_irq_save(flags);
1001 #ifdef CONFIG_X86_32
1002 if (!enabled_via_apicbase)
1006 disable_local_APIC();
1009 local_irq_restore(flags);
1013 * This is to verify that we're looking at a real local APIC.
1014 * Check these against your board if the CPUs aren't getting
1015 * started for no apparent reason.
1017 int __init verify_local_APIC(void)
1019 unsigned int reg0, reg1;
1022 * The version register is read-only in a real APIC.
1024 reg0 = apic_read(APIC_LVR);
1025 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1026 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1027 reg1 = apic_read(APIC_LVR);
1028 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1031 * The two version reads above should print the same
1032 * numbers. If the second one is different, then we
1033 * poke at a non-APIC.
1039 * Check if the version looks reasonably.
1041 reg1 = GET_APIC_VERSION(reg0);
1042 if (reg1 == 0x00 || reg1 == 0xff)
1044 reg1 = lapic_get_maxlvt();
1045 if (reg1 < 0x02 || reg1 == 0xff)
1049 * The ID register is read/write in a real APIC.
1051 reg0 = apic_read(APIC_ID);
1052 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1053 apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1054 reg1 = apic_read(APIC_ID);
1055 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1056 apic_write(APIC_ID, reg0);
1057 if (reg1 != (reg0 ^ apic->apic_id_mask))
1061 * The next two are just to see if we have sane values.
1062 * They're only really relevant if we're in Virtual Wire
1063 * compatibility mode, but most boxes are anymore.
1065 reg0 = apic_read(APIC_LVT0);
1066 apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1067 reg1 = apic_read(APIC_LVT1);
1068 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1074 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1076 void __init sync_Arb_IDs(void)
1079 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1082 if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1088 apic_wait_icr_idle();
1090 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1091 apic_write(APIC_ICR, APIC_DEST_ALLINC |
1092 APIC_INT_LEVELTRIG | APIC_DM_INIT);
1096 * An initial setup of the virtual wire mode.
1098 void __init init_bsp_APIC(void)
1103 * Don't do the setup now if we have a SMP BIOS as the
1104 * through-I/O-APIC virtual wire mode might be active.
1106 if (smp_found_config || !cpu_has_apic)
1110 * Do not trust the local APIC being empty at bootup.
1117 value = apic_read(APIC_SPIV);
1118 value &= ~APIC_VECTOR_MASK;
1119 value |= APIC_SPIV_APIC_ENABLED;
1121 #ifdef CONFIG_X86_32
1122 /* This bit is reserved on P4/Xeon and should be cleared */
1123 if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1124 (boot_cpu_data.x86 == 15))
1125 value &= ~APIC_SPIV_FOCUS_DISABLED;
1128 value |= APIC_SPIV_FOCUS_DISABLED;
1129 value |= SPURIOUS_APIC_VECTOR;
1130 apic_write(APIC_SPIV, value);
1133 * Set up the virtual wire mode.
1135 apic_write(APIC_LVT0, APIC_DM_EXTINT);
1136 value = APIC_DM_NMI;
1137 if (!lapic_is_integrated()) /* 82489DX */
1138 value |= APIC_LVT_LEVEL_TRIGGER;
1139 apic_write(APIC_LVT1, value);
1142 static void __cpuinit lapic_setup_esr(void)
1144 unsigned int oldvalue, value, maxlvt;
1146 if (!lapic_is_integrated()) {
1147 pr_info("No ESR for 82489DX.\n");
1151 if (apic->disable_esr) {
1153 * Something untraceable is creating bad interrupts on
1154 * secondary quads ... for the moment, just leave the
1155 * ESR disabled - we can't do anything useful with the
1156 * errors anyway - mbligh
1158 pr_info("Leaving ESR disabled.\n");
1162 maxlvt = lapic_get_maxlvt();
1163 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
1164 apic_write(APIC_ESR, 0);
1165 oldvalue = apic_read(APIC_ESR);
1167 /* enables sending errors */
1168 value = ERROR_APIC_VECTOR;
1169 apic_write(APIC_LVTERR, value);
1172 * spec says clear errors after enabling vector.
1175 apic_write(APIC_ESR, 0);
1176 value = apic_read(APIC_ESR);
1177 if (value != oldvalue)
1178 apic_printk(APIC_VERBOSE, "ESR value before enabling "
1179 "vector: 0x%08x after: 0x%08x\n",
1184 * setup_local_APIC - setup the local APIC
1186 * Used to setup local APIC while initializing BSP or bringin up APs.
1187 * Always called with preemption disabled.
1189 void __cpuinit setup_local_APIC(void)
1191 int cpu = smp_processor_id();
1192 unsigned int value, queued;
1193 int i, j, acked = 0;
1194 unsigned long long tsc = 0, ntsc;
1195 long long max_loops = cpu_khz;
1201 disable_ioapic_support();
1205 #ifdef CONFIG_X86_32
1206 /* Pound the ESR really hard over the head with a big hammer - mbligh */
1207 if (lapic_is_integrated() && apic->disable_esr) {
1208 apic_write(APIC_ESR, 0);
1209 apic_write(APIC_ESR, 0);
1210 apic_write(APIC_ESR, 0);
1211 apic_write(APIC_ESR, 0);
1214 perf_events_lapic_init();
1217 * Double-check whether this APIC is really registered.
1218 * This is meaningless in clustered apic mode, so we skip it.
1220 BUG_ON(!apic->apic_id_registered());
1223 * Intel recommends to set DFR, LDR and TPR before enabling
1224 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
1225 * document number 292116). So here it goes...
1227 apic->init_apic_ldr();
1229 #ifdef CONFIG_X86_32
1231 * APIC LDR is initialized. If logical_apicid mapping was
1232 * initialized during get_smp_config(), make sure it matches the
1235 i = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1236 WARN_ON(i != BAD_APICID && i != logical_smp_processor_id());
1237 /* always use the value from LDR */
1238 early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1239 logical_smp_processor_id();
1242 * Some NUMA implementations (NUMAQ) don't initialize apicid to
1243 * node mapping during NUMA init. Now that logical apicid is
1244 * guaranteed to be known, give it another chance. This is already
1245 * a bit too late - percpu allocation has already happened without
1246 * proper NUMA affinity.
1248 if (apic->x86_32_numa_cpu_node)
1249 set_apicid_to_node(early_per_cpu(x86_cpu_to_apicid, cpu),
1250 apic->x86_32_numa_cpu_node(cpu));
1254 * Set Task Priority to 'accept all'. We never change this
1257 value = apic_read(APIC_TASKPRI);
1258 value &= ~APIC_TPRI_MASK;
1259 apic_write(APIC_TASKPRI, value);
1262 * After a crash, we no longer service the interrupts and a pending
1263 * interrupt from previous kernel might still have ISR bit set.
1265 * Most probably by now CPU has serviced that pending interrupt and
1266 * it might not have done the ack_APIC_irq() because it thought,
1267 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1268 * does not clear the ISR bit and cpu thinks it has already serivced
1269 * the interrupt. Hence a vector might get locked. It was noticed
1270 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1274 for (i = APIC_ISR_NR - 1; i >= 0; i--)
1275 queued |= apic_read(APIC_IRR + i*0x10);
1277 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1278 value = apic_read(APIC_ISR + i*0x10);
1279 for (j = 31; j >= 0; j--) {
1280 if (value & (1<<j)) {
1287 printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1293 max_loops = (cpu_khz << 10) - (ntsc - tsc);
1296 } while (queued && max_loops > 0);
1297 WARN_ON(max_loops <= 0);
1300 * Now that we are all set up, enable the APIC
1302 value = apic_read(APIC_SPIV);
1303 value &= ~APIC_VECTOR_MASK;
1307 value |= APIC_SPIV_APIC_ENABLED;
1309 #ifdef CONFIG_X86_32
1311 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1312 * certain networking cards. If high frequency interrupts are
1313 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1314 * entry is masked/unmasked at a high rate as well then sooner or
1315 * later IOAPIC line gets 'stuck', no more interrupts are received
1316 * from the device. If focus CPU is disabled then the hang goes
1319 * [ This bug can be reproduced easily with a level-triggered
1320 * PCI Ne2000 networking cards and PII/PIII processors, dual
1324 * Actually disabling the focus CPU check just makes the hang less
1325 * frequent as it makes the interrupt distributon model be more
1326 * like LRU than MRU (the short-term load is more even across CPUs).
1327 * See also the comment in end_level_ioapic_irq(). --macro
1331 * - enable focus processor (bit==0)
1332 * - 64bit mode always use processor focus
1333 * so no need to set it
1335 value &= ~APIC_SPIV_FOCUS_DISABLED;
1339 * Set spurious IRQ vector
1341 value |= SPURIOUS_APIC_VECTOR;
1342 apic_write(APIC_SPIV, value);
1345 * Set up LVT0, LVT1:
1347 * set up through-local-APIC on the BP's LINT0. This is not
1348 * strictly necessary in pure symmetric-IO mode, but sometimes
1349 * we delegate interrupts to the 8259A.
1352 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1354 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1355 if (!cpu && (pic_mode || !value)) {
1356 value = APIC_DM_EXTINT;
1357 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1359 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1360 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1362 apic_write(APIC_LVT0, value);
1365 * only the BP should see the LINT1 NMI signal, obviously.
1368 value = APIC_DM_NMI;
1370 value = APIC_DM_NMI | APIC_LVT_MASKED;
1371 if (!lapic_is_integrated()) /* 82489DX */
1372 value |= APIC_LVT_LEVEL_TRIGGER;
1373 apic_write(APIC_LVT1, value);
1375 #ifdef CONFIG_X86_MCE_INTEL
1376 /* Recheck CMCI information after local APIC is up on CPU #0 */
1382 void __cpuinit end_local_APIC_setup(void)
1386 #ifdef CONFIG_X86_32
1389 /* Disable the local apic timer */
1390 value = apic_read(APIC_LVTT);
1391 value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1392 apic_write(APIC_LVTT, value);
1399 void __init bsp_end_local_APIC_setup(void)
1401 end_local_APIC_setup();
1404 * Now that local APIC setup is completed for BP, configure the fault
1405 * handling for interrupt remapping.
1407 if (intr_remapping_enabled)
1408 enable_drhd_fault_handling();
1412 #ifdef CONFIG_X86_X2APIC
1413 void check_x2apic(void)
1415 if (x2apic_enabled()) {
1416 pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1417 x2apic_preenabled = x2apic_mode = 1;
1421 void enable_x2apic(void)
1428 rdmsr(MSR_IA32_APICBASE, msr, msr2);
1429 if (!(msr & X2APIC_ENABLE)) {
1430 printk_once(KERN_INFO "Enabling x2apic\n");
1431 wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1434 #endif /* CONFIG_X86_X2APIC */
1436 int __init enable_IR(void)
1438 #ifdef CONFIG_INTR_REMAP
1439 if (!intr_remapping_supported()) {
1440 pr_debug("intr-remapping not supported\n");
1444 if (!x2apic_preenabled && skip_ioapic_setup) {
1445 pr_info("Skipped enabling intr-remap because of skipping "
1450 if (enable_intr_remapping(x2apic_supported()))
1453 pr_info("Enabled Interrupt-remapping\n");
1461 void __init enable_IR_x2apic(void)
1463 unsigned long flags;
1464 struct IO_APIC_route_entry **ioapic_entries;
1465 int ret, x2apic_enabled = 0;
1466 int dmar_table_init_ret;
1468 dmar_table_init_ret = dmar_table_init();
1469 if (dmar_table_init_ret && !x2apic_supported())
1472 ioapic_entries = alloc_ioapic_entries();
1473 if (!ioapic_entries) {
1474 pr_err("Allocate ioapic_entries failed\n");
1478 ret = save_IO_APIC_setup(ioapic_entries);
1480 pr_info("Saving IO-APIC state failed: %d\n", ret);
1484 local_irq_save(flags);
1485 legacy_pic->mask_all();
1486 mask_IO_APIC_setup(ioapic_entries);
1488 if (dmar_table_init_ret)
1494 /* IR is required if there is APIC ID > 255 even when running
1497 if (max_physical_apicid > 255 ||
1498 !hypervisor_x2apic_available())
1501 * without IR all CPUs can be addressed by IOAPIC/MSI
1502 * only in physical mode
1504 x2apic_force_phys();
1509 if (x2apic_supported() && !x2apic_mode) {
1512 pr_info("Enabled x2apic\n");
1516 if (!ret) /* IR enabling failed */
1517 restore_IO_APIC_setup(ioapic_entries);
1518 legacy_pic->restore_mask();
1519 local_irq_restore(flags);
1523 free_ioapic_entries(ioapic_entries);
1528 if (x2apic_preenabled)
1529 panic("x2apic: enabled by BIOS but kernel init failed.");
1530 else if (cpu_has_x2apic)
1531 pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
1534 #ifdef CONFIG_X86_64
1536 * Detect and enable local APICs on non-SMP boards.
1537 * Original code written by Keir Fraser.
1538 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1539 * not correctly set up (usually the APIC timer won't work etc.)
1541 static int __init detect_init_APIC(void)
1543 if (!cpu_has_apic) {
1544 pr_info("No local APIC present\n");
1548 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1553 static int __init apic_verify(void)
1558 * The APIC feature bit should now be enabled
1561 features = cpuid_edx(1);
1562 if (!(features & (1 << X86_FEATURE_APIC))) {
1563 pr_warning("Could not enable APIC!\n");
1566 set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1567 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1569 /* The BIOS may have set up the APIC at some other address */
1570 rdmsr(MSR_IA32_APICBASE, l, h);
1571 if (l & MSR_IA32_APICBASE_ENABLE)
1572 mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1574 pr_info("Found and enabled local APIC!\n");
1578 int __init apic_force_enable(unsigned long addr)
1586 * Some BIOSes disable the local APIC in the APIC_BASE
1587 * MSR. This can only be done in software for Intel P6 or later
1588 * and AMD K7 (Model > 1) or later.
1590 rdmsr(MSR_IA32_APICBASE, l, h);
1591 if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1592 pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1593 l &= ~MSR_IA32_APICBASE_BASE;
1594 l |= MSR_IA32_APICBASE_ENABLE | addr;
1595 wrmsr(MSR_IA32_APICBASE, l, h);
1596 enabled_via_apicbase = 1;
1598 return apic_verify();
1602 * Detect and initialize APIC
1604 static int __init detect_init_APIC(void)
1606 /* Disabled by kernel option? */
1610 switch (boot_cpu_data.x86_vendor) {
1611 case X86_VENDOR_AMD:
1612 if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1613 (boot_cpu_data.x86 >= 15))
1616 case X86_VENDOR_INTEL:
1617 if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1618 (boot_cpu_data.x86 == 5 && cpu_has_apic))
1625 if (!cpu_has_apic) {
1627 * Over-ride BIOS and try to enable the local APIC only if
1628 * "lapic" specified.
1630 if (!force_enable_local_apic) {
1631 pr_info("Local APIC disabled by BIOS -- "
1632 "you can enable it with \"lapic\"\n");
1635 if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1647 pr_info("No local APIC present or hardware disabled\n");
1653 * init_apic_mappings - initialize APIC mappings
1655 void __init init_apic_mappings(void)
1657 unsigned int new_apicid;
1660 boot_cpu_physical_apicid = read_apic_id();
1664 /* If no local APIC can be found return early */
1665 if (!smp_found_config && detect_init_APIC()) {
1666 /* lets NOP'ify apic operations */
1667 pr_info("APIC: disable apic facility\n");
1670 apic_phys = mp_lapic_addr;
1673 * acpi lapic path already maps that address in
1674 * acpi_register_lapic_address()
1676 if (!acpi_lapic && !smp_found_config)
1677 register_lapic_address(apic_phys);
1681 * Fetch the APIC ID of the BSP in case we have a
1682 * default configuration (or the MP table is broken).
1684 new_apicid = read_apic_id();
1685 if (boot_cpu_physical_apicid != new_apicid) {
1686 boot_cpu_physical_apicid = new_apicid;
1688 * yeah -- we lie about apic_version
1689 * in case if apic was disabled via boot option
1690 * but it's not a problem for SMP compiled kernel
1691 * since smp_sanity_check is prepared for such a case
1692 * and disable smp mode
1694 apic_version[new_apicid] =
1695 GET_APIC_VERSION(apic_read(APIC_LVR));
1699 void __init register_lapic_address(unsigned long address)
1701 mp_lapic_addr = address;
1704 set_fixmap_nocache(FIX_APIC_BASE, address);
1705 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1706 APIC_BASE, mp_lapic_addr);
1708 if (boot_cpu_physical_apicid == -1U) {
1709 boot_cpu_physical_apicid = read_apic_id();
1710 apic_version[boot_cpu_physical_apicid] =
1711 GET_APIC_VERSION(apic_read(APIC_LVR));
1716 * This initializes the IO-APIC and APIC hardware if this is
1719 int apic_version[MAX_LOCAL_APIC];
1721 int __init APIC_init_uniprocessor(void)
1724 pr_info("Apic disabled\n");
1727 #ifdef CONFIG_X86_64
1728 if (!cpu_has_apic) {
1730 pr_info("Apic disabled by BIOS\n");
1734 if (!smp_found_config && !cpu_has_apic)
1738 * Complain if the BIOS pretends there is one.
1740 if (!cpu_has_apic &&
1741 APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1742 pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1743 boot_cpu_physical_apicid);
1748 default_setup_apic_routing();
1750 verify_local_APIC();
1753 #ifdef CONFIG_X86_64
1754 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1757 * Hack: In case of kdump, after a crash, kernel might be booting
1758 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1759 * might be zero if read from MP tables. Get it from LAPIC.
1761 # ifdef CONFIG_CRASH_DUMP
1762 boot_cpu_physical_apicid = read_apic_id();
1765 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1768 #ifdef CONFIG_X86_IO_APIC
1770 * Now enable IO-APICs, actually call clear_IO_APIC
1771 * We need clear_IO_APIC before enabling error vector
1773 if (!skip_ioapic_setup && nr_ioapics)
1777 bsp_end_local_APIC_setup();
1779 #ifdef CONFIG_X86_IO_APIC
1780 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1787 x86_init.timers.setup_percpu_clockev();
1792 * Local APIC interrupts
1796 * This interrupt should _never_ happen with our APIC/SMP architecture
1798 void smp_spurious_interrupt(struct pt_regs *regs)
1805 * Check if this really is a spurious interrupt and ACK it
1806 * if it is a vectored one. Just in case...
1807 * Spurious interrupts should not be ACKed.
1809 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1810 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1813 inc_irq_stat(irq_spurious_count);
1815 /* see sw-dev-man vol 3, chapter 7.4.13.5 */
1816 pr_info("spurious APIC interrupt on CPU#%d, "
1817 "should never happen.\n", smp_processor_id());
1822 * This interrupt should never happen with our APIC/SMP architecture
1824 void smp_error_interrupt(struct pt_regs *regs)
1828 static const char * const error_interrupt_reason[] = {
1829 "Send CS error", /* APIC Error Bit 0 */
1830 "Receive CS error", /* APIC Error Bit 1 */
1831 "Send accept error", /* APIC Error Bit 2 */
1832 "Receive accept error", /* APIC Error Bit 3 */
1833 "Redirectable IPI", /* APIC Error Bit 4 */
1834 "Send illegal vector", /* APIC Error Bit 5 */
1835 "Received illegal vector", /* APIC Error Bit 6 */
1836 "Illegal register address", /* APIC Error Bit 7 */
1841 /* First tickle the hardware, only then report what went on. -- REW */
1842 v0 = apic_read(APIC_ESR);
1843 apic_write(APIC_ESR, 0);
1844 v1 = apic_read(APIC_ESR);
1846 atomic_inc(&irq_err_count);
1848 apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
1849 smp_processor_id(), v0 , v1);
1854 apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
1859 apic_printk(APIC_DEBUG, KERN_CONT "\n");
1865 * connect_bsp_APIC - attach the APIC to the interrupt system
1867 void __init connect_bsp_APIC(void)
1869 #ifdef CONFIG_X86_32
1872 * Do not trust the local APIC being empty at bootup.
1876 * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
1877 * local APIC to INT and NMI lines.
1879 apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1880 "enabling APIC mode.\n");
1884 if (apic->enable_apic_mode)
1885 apic->enable_apic_mode();
1889 * disconnect_bsp_APIC - detach the APIC from the interrupt system
1890 * @virt_wire_setup: indicates, whether virtual wire mode is selected
1892 * Virtual wire mode is necessary to deliver legacy interrupts even when the
1895 void disconnect_bsp_APIC(int virt_wire_setup)
1899 #ifdef CONFIG_X86_32
1902 * Put the board back into PIC mode (has an effect only on
1903 * certain older boards). Note that APIC interrupts, including
1904 * IPIs, won't work beyond this point! The only exception are
1907 apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1908 "entering PIC mode.\n");
1914 /* Go back to Virtual Wire compatibility mode */
1916 /* For the spurious interrupt use vector F, and enable it */
1917 value = apic_read(APIC_SPIV);
1918 value &= ~APIC_VECTOR_MASK;
1919 value |= APIC_SPIV_APIC_ENABLED;
1921 apic_write(APIC_SPIV, value);
1923 if (!virt_wire_setup) {
1925 * For LVT0 make it edge triggered, active high,
1926 * external and enabled
1928 value = apic_read(APIC_LVT0);
1929 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1930 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1931 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1932 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1933 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1934 apic_write(APIC_LVT0, value);
1937 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1941 * For LVT1 make it edge triggered, active high,
1944 value = apic_read(APIC_LVT1);
1945 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1946 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1947 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1948 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1949 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1950 apic_write(APIC_LVT1, value);
1953 void __cpuinit generic_processor_info(int apicid, int version)
1957 if (num_processors >= nr_cpu_ids) {
1958 int max = nr_cpu_ids;
1959 int thiscpu = max + disabled_cpus;
1962 "ACPI: NR_CPUS/possible_cpus limit of %i reached."
1963 " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1970 if (apicid == boot_cpu_physical_apicid) {
1972 * x86_bios_cpu_apicid is required to have processors listed
1973 * in same order as logical cpu numbers. Hence the first
1974 * entry is BSP, and so on.
1975 * boot_cpu_init() already hold bit 0 in cpu_present_mask
1980 cpu = cpumask_next_zero(-1, cpu_present_mask);
1985 if (version == 0x0) {
1986 pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
1990 apic_version[apicid] = version;
1992 if (version != apic_version[boot_cpu_physical_apicid]) {
1993 pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
1994 apic_version[boot_cpu_physical_apicid], cpu, version);
1997 physid_set(apicid, phys_cpu_present_map);
1998 if (apicid > max_physical_apicid)
1999 max_physical_apicid = apicid;
2001 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2002 early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2003 early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2005 #ifdef CONFIG_X86_32
2006 early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2007 apic->x86_32_early_logical_apicid(cpu);
2009 set_cpu_possible(cpu, true);
2010 set_cpu_present(cpu, true);
2013 int hard_smp_processor_id(void)
2015 return read_apic_id();
2018 void default_init_apic_ldr(void)
2022 apic_write(APIC_DFR, APIC_DFR_VALUE);
2023 val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2024 val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2025 apic_write(APIC_LDR, val);
2035 * 'active' is true if the local APIC was enabled by us and
2036 * not the BIOS; this signifies that we are also responsible
2037 * for disabling it before entering apm/acpi suspend
2040 /* r/w apic fields */
2041 unsigned int apic_id;
2042 unsigned int apic_taskpri;
2043 unsigned int apic_ldr;
2044 unsigned int apic_dfr;
2045 unsigned int apic_spiv;
2046 unsigned int apic_lvtt;
2047 unsigned int apic_lvtpc;
2048 unsigned int apic_lvt0;
2049 unsigned int apic_lvt1;
2050 unsigned int apic_lvterr;
2051 unsigned int apic_tmict;
2052 unsigned int apic_tdcr;
2053 unsigned int apic_thmr;
2056 static int lapic_suspend(void)
2058 unsigned long flags;
2061 if (!apic_pm_state.active)
2064 maxlvt = lapic_get_maxlvt();
2066 apic_pm_state.apic_id = apic_read(APIC_ID);
2067 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2068 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2069 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2070 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2071 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2073 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2074 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2075 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2076 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2077 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2078 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2079 #ifdef CONFIG_X86_THERMAL_VECTOR
2081 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2084 local_irq_save(flags);
2085 disable_local_APIC();
2087 if (intr_remapping_enabled)
2088 disable_intr_remapping();
2090 local_irq_restore(flags);
2094 static void lapic_resume(void)
2097 unsigned long flags;
2099 struct IO_APIC_route_entry **ioapic_entries = NULL;
2101 if (!apic_pm_state.active)
2104 local_irq_save(flags);
2105 if (intr_remapping_enabled) {
2106 ioapic_entries = alloc_ioapic_entries();
2107 if (!ioapic_entries) {
2108 WARN(1, "Alloc ioapic_entries in lapic resume failed.");
2112 ret = save_IO_APIC_setup(ioapic_entries);
2114 WARN(1, "Saving IO-APIC state failed: %d\n", ret);
2115 free_ioapic_entries(ioapic_entries);
2119 mask_IO_APIC_setup(ioapic_entries);
2120 legacy_pic->mask_all();
2127 * Make sure the APICBASE points to the right address
2129 * FIXME! This will be wrong if we ever support suspend on
2130 * SMP! We'll need to do this as part of the CPU restore!
2132 rdmsr(MSR_IA32_APICBASE, l, h);
2133 l &= ~MSR_IA32_APICBASE_BASE;
2134 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2135 wrmsr(MSR_IA32_APICBASE, l, h);
2138 maxlvt = lapic_get_maxlvt();
2139 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2140 apic_write(APIC_ID, apic_pm_state.apic_id);
2141 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2142 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2143 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2144 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2145 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2146 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2147 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2149 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2152 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2153 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2154 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2155 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2156 apic_write(APIC_ESR, 0);
2157 apic_read(APIC_ESR);
2158 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2159 apic_write(APIC_ESR, 0);
2160 apic_read(APIC_ESR);
2162 if (intr_remapping_enabled) {
2163 reenable_intr_remapping(x2apic_mode);
2164 legacy_pic->restore_mask();
2165 restore_IO_APIC_setup(ioapic_entries);
2166 free_ioapic_entries(ioapic_entries);
2169 local_irq_restore(flags);
2173 * This device has no shutdown method - fully functioning local APICs
2174 * are needed on every CPU up until machine_halt/restart/poweroff.
2177 static struct syscore_ops lapic_syscore_ops = {
2178 .resume = lapic_resume,
2179 .suspend = lapic_suspend,
2182 static void __cpuinit apic_pm_activate(void)
2184 apic_pm_state.active = 1;
2187 static int __init init_lapic_sysfs(void)
2189 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2191 register_syscore_ops(&lapic_syscore_ops);
2196 /* local apic needs to resume before other devices access its registers. */
2197 core_initcall(init_lapic_sysfs);
2199 #else /* CONFIG_PM */
2201 static void apic_pm_activate(void) { }
2203 #endif /* CONFIG_PM */
2205 #ifdef CONFIG_X86_64
2207 static int __cpuinit apic_cluster_num(void)
2209 int i, clusters, zeros;
2211 u16 *bios_cpu_apicid;
2212 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2214 bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2215 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2217 for (i = 0; i < nr_cpu_ids; i++) {
2218 /* are we being called early in kernel startup? */
2219 if (bios_cpu_apicid) {
2220 id = bios_cpu_apicid[i];
2221 } else if (i < nr_cpu_ids) {
2223 id = per_cpu(x86_bios_cpu_apicid, i);
2229 if (id != BAD_APICID)
2230 __set_bit(APIC_CLUSTERID(id), clustermap);
2233 /* Problem: Partially populated chassis may not have CPUs in some of
2234 * the APIC clusters they have been allocated. Only present CPUs have
2235 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2236 * Since clusters are allocated sequentially, count zeros only if
2237 * they are bounded by ones.
2241 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2242 if (test_bit(i, clustermap)) {
2243 clusters += 1 + zeros;
2252 static int __cpuinitdata multi_checked;
2253 static int __cpuinitdata multi;
2255 static int __cpuinit set_multi(const struct dmi_system_id *d)
2259 pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2264 static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2266 .callback = set_multi,
2267 .ident = "IBM System Summit2",
2269 DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2270 DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2276 static void __cpuinit dmi_check_multi(void)
2281 dmi_check_system(multi_dmi_table);
2286 * apic_is_clustered_box() -- Check if we can expect good TSC
2288 * Thus far, the major user of this is IBM's Summit2 series:
2289 * Clustered boxes may have unsynced TSC problems if they are
2291 * Use DMI to check them
2293 __cpuinit int apic_is_clustered_box(void)
2303 * ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2304 * not guaranteed to be synced between boards
2306 if (apic_cluster_num() > 1)
2314 * APIC command line parameters
2316 static int __init setup_disableapic(char *arg)
2319 setup_clear_cpu_cap(X86_FEATURE_APIC);
2322 early_param("disableapic", setup_disableapic);
2324 /* same as disableapic, for compatibility */
2325 static int __init setup_nolapic(char *arg)
2327 return setup_disableapic(arg);
2329 early_param("nolapic", setup_nolapic);
2331 static int __init parse_lapic_timer_c2_ok(char *arg)
2333 local_apic_timer_c2_ok = 1;
2336 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2338 static int __init parse_disable_apic_timer(char *arg)
2340 disable_apic_timer = 1;
2343 early_param("noapictimer", parse_disable_apic_timer);
2345 static int __init parse_nolapic_timer(char *arg)
2347 disable_apic_timer = 1;
2350 early_param("nolapic_timer", parse_nolapic_timer);
2352 static int __init apic_set_verbosity(char *arg)
2355 #ifdef CONFIG_X86_64
2356 skip_ioapic_setup = 0;
2362 if (strcmp("debug", arg) == 0)
2363 apic_verbosity = APIC_DEBUG;
2364 else if (strcmp("verbose", arg) == 0)
2365 apic_verbosity = APIC_VERBOSE;
2367 pr_warning("APIC Verbosity level %s not recognised"
2368 " use apic=verbose or apic=debug\n", arg);
2374 early_param("apic", apic_set_verbosity);
2376 static int __init lapic_insert_resource(void)
2381 /* Put local APIC into the resource map. */
2382 lapic_resource.start = apic_phys;
2383 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2384 insert_resource(&iomem_resource, &lapic_resource);
2390 * need call insert after e820_reserve_resources()
2391 * that is using request_resource
2393 late_initcall(lapic_insert_resource);