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/interrupt.h>
23 #include <linux/mc146818rtc.h>
24 #include <linux/kernel_stat.h>
25 #include <linux/sysdev.h>
26 #include <linux/ioport.h>
27 #include <linux/clockchips.h>
28 #include <linux/acpi_pmtmr.h>
29 #include <linux/module.h>
30 #include <linux/dmar.h>
32 #include <asm/atomic.h>
35 #include <asm/mpspec.h>
37 #include <asm/pgalloc.h>
40 #include <asm/proto.h>
41 #include <asm/timex.h>
43 #include <asm/i8259.h>
46 #include <mach_apic.h>
48 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
49 static int disable_apic_timer __cpuinitdata;
50 static int apic_calibrate_pmtmr __initdata;
55 /* x2apic enabled before OS handover */
56 int x2apic_preenabled;
58 /* Local APIC timer works in C2 */
59 int local_apic_timer_c2_ok;
60 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
63 * Debug level, exported for io_apic.c
65 unsigned int apic_verbosity;
67 /* Have we found an MP table */
70 static struct resource lapic_resource = {
72 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
75 static unsigned int calibration_result;
77 static int lapic_next_event(unsigned long delta,
78 struct clock_event_device *evt);
79 static void lapic_timer_setup(enum clock_event_mode mode,
80 struct clock_event_device *evt);
81 static void lapic_timer_broadcast(cpumask_t mask);
82 static void apic_pm_activate(void);
85 * The local apic timer can be used for any function which is CPU local.
87 static struct clock_event_device lapic_clockevent = {
89 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
90 | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
92 .set_mode = lapic_timer_setup,
93 .set_next_event = lapic_next_event,
94 .broadcast = lapic_timer_broadcast,
98 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
100 static unsigned long apic_phys;
101 unsigned int __cpuinitdata maxcpus = NR_CPUS;
103 unsigned long mp_lapic_addr;
106 * Get the LAPIC version
108 static inline int lapic_get_version(void)
110 return GET_APIC_VERSION(apic_read(APIC_LVR));
114 * Check, if the APIC is integrated or a separate chip
116 static inline int lapic_is_integrated(void)
121 return APIC_INTEGRATED(lapic_get_version());
126 * Check, whether this is a modern or a first generation APIC
128 static int modern_apic(void)
130 /* AMD systems use old APIC versions, so check the CPU */
131 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
132 boot_cpu_data.x86 >= 0xf)
134 return lapic_get_version() >= 0x14;
138 * Paravirt kernels also might be using these below ops. So we still
139 * use generic apic_read()/apic_write(), which might be pointing to different
140 * ops in PARAVIRT case.
142 void xapic_wait_icr_idle(void)
144 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
148 u32 safe_xapic_wait_icr_idle(void)
155 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
159 } while (timeout++ < 1000);
164 void xapic_icr_write(u32 low, u32 id)
166 apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
167 apic_write(APIC_ICR, low);
170 u64 xapic_icr_read(void)
174 icr2 = apic_read(APIC_ICR2);
175 icr1 = apic_read(APIC_ICR);
177 return icr1 | ((u64)icr2 << 32);
180 static struct apic_ops xapic_ops = {
181 .read = native_apic_mem_read,
182 .write = native_apic_mem_write,
183 .icr_read = xapic_icr_read,
184 .icr_write = xapic_icr_write,
185 .wait_icr_idle = xapic_wait_icr_idle,
186 .safe_wait_icr_idle = safe_xapic_wait_icr_idle,
189 struct apic_ops __read_mostly *apic_ops = &xapic_ops;
190 EXPORT_SYMBOL_GPL(apic_ops);
192 static void x2apic_wait_icr_idle(void)
194 /* no need to wait for icr idle in x2apic */
198 static u32 safe_x2apic_wait_icr_idle(void)
200 /* no need to wait for icr idle in x2apic */
204 void x2apic_icr_write(u32 low, u32 id)
206 wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
209 u64 x2apic_icr_read(void)
213 rdmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), val);
217 static struct apic_ops x2apic_ops = {
218 .read = native_apic_msr_read,
219 .write = native_apic_msr_write,
220 .icr_read = x2apic_icr_read,
221 .icr_write = x2apic_icr_write,
222 .wait_icr_idle = x2apic_wait_icr_idle,
223 .safe_wait_icr_idle = safe_x2apic_wait_icr_idle,
227 * enable_NMI_through_LVT0 - enable NMI through local vector table 0
229 void __cpuinit enable_NMI_through_LVT0(void)
233 /* unmask and set to NMI */
236 /* Level triggered for 82489DX (32bit mode) */
237 if (!lapic_is_integrated())
238 v |= APIC_LVT_LEVEL_TRIGGER;
240 apic_write(APIC_LVT0, v);
244 * lapic_get_maxlvt - get the maximum number of local vector table entries
246 int lapic_get_maxlvt(void)
250 v = apic_read(APIC_LVR);
252 * - we always have APIC integrated on 64bit mode
253 * - 82489DXs do not report # of LVT entries
255 return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
262 /* Clock divisor is set to 1 */
263 #define APIC_DIVISOR 1
266 * This function sets up the local APIC timer, with a timeout of
267 * 'clocks' APIC bus clock. During calibration we actually call
268 * this function twice on the boot CPU, once with a bogus timeout
269 * value, second time for real. The other (noncalibrating) CPUs
270 * call this function only once, with the real, calibrated value.
272 * We do reads before writes even if unnecessary, to get around the
273 * P5 APIC double write bug.
275 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
277 unsigned int lvtt_value, tmp_value;
279 lvtt_value = LOCAL_TIMER_VECTOR;
281 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
282 if (!lapic_is_integrated())
283 lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
286 lvtt_value |= APIC_LVT_MASKED;
288 apic_write(APIC_LVTT, lvtt_value);
293 tmp_value = apic_read(APIC_TDCR);
294 apic_write(APIC_TDCR, (tmp_value
295 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
299 apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
303 * Setup extended LVT, AMD specific (K8, family 10h)
305 * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
306 * MCE interrupts are supported. Thus MCE offset must be set to 0.
309 #define APIC_EILVT_LVTOFF_MCE 0
310 #define APIC_EILVT_LVTOFF_IBS 1
312 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
314 unsigned long reg = (lvt_off << 4) + APIC_EILVT0;
315 unsigned int v = (mask << 16) | (msg_type << 8) | vector;
320 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
322 setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
323 return APIC_EILVT_LVTOFF_MCE;
326 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
328 setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
329 return APIC_EILVT_LVTOFF_IBS;
333 * Program the next event, relative to now
335 static int lapic_next_event(unsigned long delta,
336 struct clock_event_device *evt)
338 apic_write(APIC_TMICT, delta);
343 * Setup the lapic timer in periodic or oneshot mode
345 static void lapic_timer_setup(enum clock_event_mode mode,
346 struct clock_event_device *evt)
351 /* Lapic used as dummy for broadcast ? */
352 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
355 local_irq_save(flags);
358 case CLOCK_EVT_MODE_PERIODIC:
359 case CLOCK_EVT_MODE_ONESHOT:
360 __setup_APIC_LVTT(calibration_result,
361 mode != CLOCK_EVT_MODE_PERIODIC, 1);
363 case CLOCK_EVT_MODE_UNUSED:
364 case CLOCK_EVT_MODE_SHUTDOWN:
365 v = apic_read(APIC_LVTT);
366 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
367 apic_write(APIC_LVTT, v);
369 case CLOCK_EVT_MODE_RESUME:
370 /* Nothing to do here */
374 local_irq_restore(flags);
378 * Local APIC timer broadcast function
380 static void lapic_timer_broadcast(cpumask_t mask)
383 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
388 * Setup the local APIC timer for this CPU. Copy the initilized values
389 * of the boot CPU and register the clock event in the framework.
391 static void setup_APIC_timer(void)
393 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
395 memcpy(levt, &lapic_clockevent, sizeof(*levt));
396 levt->cpumask = cpumask_of_cpu(smp_processor_id());
398 clockevents_register_device(levt);
402 * In this function we calibrate APIC bus clocks to the external
403 * timer. Unfortunately we cannot use jiffies and the timer irq
404 * to calibrate, since some later bootup code depends on getting
405 * the first irq? Ugh.
407 * We want to do the calibration only once since we
408 * want to have local timer irqs syncron. CPUs connected
409 * by the same APIC bus have the very same bus frequency.
410 * And we want to have irqs off anyways, no accidental
414 #define TICK_COUNT 100000000
416 static int __init calibrate_APIC_clock(void)
418 unsigned apic, apic_start;
419 unsigned long tsc, tsc_start;
425 * Put whatever arbitrary (but long enough) timeout
426 * value into the APIC clock, we just want to get the
427 * counter running for calibration.
429 * No interrupt enable !
431 __setup_APIC_LVTT(250000000, 0, 0);
433 apic_start = apic_read(APIC_TMCCT);
434 #ifdef CONFIG_X86_PM_TIMER
435 if (apic_calibrate_pmtmr && pmtmr_ioport) {
436 pmtimer_wait(5000); /* 5ms wait */
437 apic = apic_read(APIC_TMCCT);
438 result = (apic_start - apic) * 1000L / 5;
445 apic = apic_read(APIC_TMCCT);
447 } while ((tsc - tsc_start) < TICK_COUNT &&
448 (apic_start - apic) < TICK_COUNT);
450 result = (apic_start - apic) * 1000L * tsc_khz /
456 printk(KERN_DEBUG "APIC timer calibration result %d\n", result);
458 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
459 result / 1000 / 1000, result / 1000 % 1000);
461 /* Calculate the scaled math multiplication factor */
462 lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC,
463 lapic_clockevent.shift);
464 lapic_clockevent.max_delta_ns =
465 clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
466 lapic_clockevent.min_delta_ns =
467 clockevent_delta2ns(0xF, &lapic_clockevent);
469 calibration_result = (result * APIC_DIVISOR) / HZ;
472 * Do a sanity check on the APIC calibration result
474 if (calibration_result < (1000000 / HZ)) {
476 "APIC frequency too slow, disabling apic timer\n");
484 * Setup the boot APIC
486 * Calibrate and verify the result.
488 void __init setup_boot_APIC_clock(void)
491 * The local apic timer can be disabled via the kernel
492 * commandline or from the CPU detection code. Register the lapic
493 * timer as a dummy clock event source on SMP systems, so the
494 * broadcast mechanism is used. On UP systems simply ignore it.
496 if (disable_apic_timer) {
497 printk(KERN_INFO "Disabling APIC timer\n");
498 /* No broadcast on UP ! */
499 if (num_possible_cpus() > 1) {
500 lapic_clockevent.mult = 1;
506 apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
507 "calibrating APIC timer ...\n");
509 if (calibrate_APIC_clock()) {
510 /* No broadcast on UP ! */
511 if (num_possible_cpus() > 1)
517 * If nmi_watchdog is set to IO_APIC, we need the
518 * PIT/HPET going. Otherwise register lapic as a dummy
521 if (nmi_watchdog != NMI_IO_APIC)
522 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
524 printk(KERN_WARNING "APIC timer registered as dummy,"
525 " due to nmi_watchdog=%d!\n", nmi_watchdog);
527 /* Setup the lapic or request the broadcast */
531 void __cpuinit setup_secondary_APIC_clock(void)
537 * The guts of the apic timer interrupt
539 static void local_apic_timer_interrupt(void)
541 int cpu = smp_processor_id();
542 struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
545 * Normally we should not be here till LAPIC has been initialized but
546 * in some cases like kdump, its possible that there is a pending LAPIC
547 * timer interrupt from previous kernel's context and is delivered in
548 * new kernel the moment interrupts are enabled.
550 * Interrupts are enabled early and LAPIC is setup much later, hence
551 * its possible that when we get here evt->event_handler is NULL.
552 * Check for event_handler being NULL and discard the interrupt as
555 if (!evt->event_handler) {
557 "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
559 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
564 * the NMI deadlock-detector uses this.
566 add_pda(apic_timer_irqs, 1);
568 evt->event_handler(evt);
572 * Local APIC timer interrupt. This is the most natural way for doing
573 * local interrupts, but local timer interrupts can be emulated by
574 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
576 * [ if a single-CPU system runs an SMP kernel then we call the local
577 * interrupt as well. Thus we cannot inline the local irq ... ]
579 void smp_apic_timer_interrupt(struct pt_regs *regs)
581 struct pt_regs *old_regs = set_irq_regs(regs);
584 * NOTE! We'd better ACK the irq immediately,
585 * because timer handling can be slow.
589 * update_process_times() expects us to have done irq_enter().
590 * Besides, if we don't timer interrupts ignore the global
591 * interrupt lock, which is the WrongThing (tm) to do.
595 local_apic_timer_interrupt();
598 set_irq_regs(old_regs);
601 int setup_profiling_timer(unsigned int multiplier)
608 * Local APIC start and shutdown
612 * clear_local_APIC - shutdown the local APIC
614 * This is called, when a CPU is disabled and before rebooting, so the state of
615 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
616 * leftovers during boot.
618 void clear_local_APIC(void)
623 /* APIC hasn't been mapped yet */
627 maxlvt = lapic_get_maxlvt();
629 * Masking an LVT entry can trigger a local APIC error
630 * if the vector is zero. Mask LVTERR first to prevent this.
633 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
634 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
637 * Careful: we have to set masks only first to deassert
638 * any level-triggered sources.
640 v = apic_read(APIC_LVTT);
641 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
642 v = apic_read(APIC_LVT0);
643 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
644 v = apic_read(APIC_LVT1);
645 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
647 v = apic_read(APIC_LVTPC);
648 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
651 /* lets not touch this if we didn't frob it */
652 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(X86_MCE_INTEL)
654 v = apic_read(APIC_LVTTHMR);
655 apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
659 * Clean APIC state for other OSs:
661 apic_write(APIC_LVTT, APIC_LVT_MASKED);
662 apic_write(APIC_LVT0, APIC_LVT_MASKED);
663 apic_write(APIC_LVT1, APIC_LVT_MASKED);
665 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
667 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
669 /* Integrated APIC (!82489DX) ? */
670 if (lapic_is_integrated()) {
672 /* Clear ESR due to Pentium errata 3AP and 11AP */
673 apic_write(APIC_ESR, 0);
679 * disable_local_APIC - clear and disable the local APIC
681 void disable_local_APIC(void)
688 * Disable APIC (implies clearing of registers
691 value = apic_read(APIC_SPIV);
692 value &= ~APIC_SPIV_APIC_ENABLED;
693 apic_write(APIC_SPIV, value);
697 * When LAPIC was disabled by the BIOS and enabled by the kernel,
698 * restore the disabled state.
700 if (enabled_via_apicbase) {
703 rdmsr(MSR_IA32_APICBASE, l, h);
704 l &= ~MSR_IA32_APICBASE_ENABLE;
705 wrmsr(MSR_IA32_APICBASE, l, h);
711 * If Linux enabled the LAPIC against the BIOS default disable it down before
712 * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and
713 * not power-off. Additionally clear all LVT entries before disable_local_APIC
714 * for the case where Linux didn't enable the LAPIC.
716 void lapic_shutdown(void)
723 local_irq_save(flags);
726 if (!enabled_via_apicbase)
730 disable_local_APIC();
733 local_irq_restore(flags);
737 * This is to verify that we're looking at a real local APIC.
738 * Check these against your board if the CPUs aren't getting
739 * started for no apparent reason.
741 int __init verify_local_APIC(void)
743 unsigned int reg0, reg1;
746 * The version register is read-only in a real APIC.
748 reg0 = apic_read(APIC_LVR);
749 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
750 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
751 reg1 = apic_read(APIC_LVR);
752 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
755 * The two version reads above should print the same
756 * numbers. If the second one is different, then we
757 * poke at a non-APIC.
763 * Check if the version looks reasonably.
765 reg1 = GET_APIC_VERSION(reg0);
766 if (reg1 == 0x00 || reg1 == 0xff)
768 reg1 = lapic_get_maxlvt();
769 if (reg1 < 0x02 || reg1 == 0xff)
773 * The ID register is read/write in a real APIC.
775 reg0 = apic_read(APIC_ID);
776 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
777 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
778 reg1 = apic_read(APIC_ID);
779 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
780 apic_write(APIC_ID, reg0);
781 if (reg1 != (reg0 ^ APIC_ID_MASK))
785 * The next two are just to see if we have sane values.
786 * They're only really relevant if we're in Virtual Wire
787 * compatibility mode, but most boxes are anymore.
789 reg0 = apic_read(APIC_LVT0);
790 apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
791 reg1 = apic_read(APIC_LVT1);
792 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
798 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
800 void __init sync_Arb_IDs(void)
803 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
806 if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
812 apic_wait_icr_idle();
814 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
815 apic_write(APIC_ICR, APIC_DEST_ALLINC |
816 APIC_INT_LEVELTRIG | APIC_DM_INIT);
820 * An initial setup of the virtual wire mode.
822 void __init init_bsp_APIC(void)
827 * Don't do the setup now if we have a SMP BIOS as the
828 * through-I/O-APIC virtual wire mode might be active.
830 if (smp_found_config || !cpu_has_apic)
834 * Do not trust the local APIC being empty at bootup.
841 value = apic_read(APIC_SPIV);
842 value &= ~APIC_VECTOR_MASK;
843 value |= APIC_SPIV_APIC_ENABLED;
846 /* This bit is reserved on P4/Xeon and should be cleared */
847 if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
848 (boot_cpu_data.x86 == 15))
849 value &= ~APIC_SPIV_FOCUS_DISABLED;
852 value |= APIC_SPIV_FOCUS_DISABLED;
853 value |= SPURIOUS_APIC_VECTOR;
854 apic_write(APIC_SPIV, value);
857 * Set up the virtual wire mode.
859 apic_write(APIC_LVT0, APIC_DM_EXTINT);
861 if (!lapic_is_integrated()) /* 82489DX */
862 value |= APIC_LVT_LEVEL_TRIGGER;
863 apic_write(APIC_LVT1, value);
866 static void __cpuinit lapic_setup_esr(void)
868 unsigned long oldvalue, value, maxlvt;
869 if (lapic_is_integrated() && !esr_disable) {
872 * Something untraceable is creating bad interrupts on
873 * secondary quads ... for the moment, just leave the
874 * ESR disabled - we can't do anything useful with the
875 * errors anyway - mbligh
877 printk(KERN_INFO "Leaving ESR disabled.\n");
881 maxlvt = lapic_get_maxlvt();
882 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
883 apic_write(APIC_ESR, 0);
884 oldvalue = apic_read(APIC_ESR);
886 /* enables sending errors */
887 value = ERROR_APIC_VECTOR;
888 apic_write(APIC_LVTERR, value);
890 * spec says clear errors after enabling vector.
893 apic_write(APIC_ESR, 0);
894 value = apic_read(APIC_ESR);
895 if (value != oldvalue)
896 apic_printk(APIC_VERBOSE, "ESR value before enabling "
897 "vector: 0x%08lx after: 0x%08lx\n",
900 printk(KERN_INFO "No ESR for 82489DX.\n");
906 * setup_local_APIC - setup the local APIC
908 void __cpuinit setup_local_APIC(void)
914 value = apic_read(APIC_LVR);
916 BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);
919 * Double-check whether this APIC is really registered.
920 * This is meaningless in clustered apic mode, so we skip it.
922 if (!apic_id_registered())
926 * Intel recommends to set DFR, LDR and TPR before enabling
927 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
928 * document number 292116). So here it goes...
933 * Set Task Priority to 'accept all'. We never change this
936 value = apic_read(APIC_TASKPRI);
937 value &= ~APIC_TPRI_MASK;
938 apic_write(APIC_TASKPRI, value);
941 * After a crash, we no longer service the interrupts and a pending
942 * interrupt from previous kernel might still have ISR bit set.
944 * Most probably by now CPU has serviced that pending interrupt and
945 * it might not have done the ack_APIC_irq() because it thought,
946 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
947 * does not clear the ISR bit and cpu thinks it has already serivced
948 * the interrupt. Hence a vector might get locked. It was noticed
949 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
951 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
952 value = apic_read(APIC_ISR + i*0x10);
953 for (j = 31; j >= 0; j--) {
960 * Now that we are all set up, enable the APIC
962 value = apic_read(APIC_SPIV);
963 value &= ~APIC_VECTOR_MASK;
967 value |= APIC_SPIV_APIC_ENABLED;
969 /* We always use processor focus */
972 * Set spurious IRQ vector
974 value |= SPURIOUS_APIC_VECTOR;
975 apic_write(APIC_SPIV, value);
980 * set up through-local-APIC on the BP's LINT0. This is not
981 * strictly necessary in pure symmetric-IO mode, but sometimes
982 * we delegate interrupts to the 8259A.
985 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
987 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
988 if (!smp_processor_id() && !value) {
989 value = APIC_DM_EXTINT;
990 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
993 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
994 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
997 apic_write(APIC_LVT0, value);
1000 * only the BP should see the LINT1 NMI signal, obviously.
1002 if (!smp_processor_id())
1003 value = APIC_DM_NMI;
1005 value = APIC_DM_NMI | APIC_LVT_MASKED;
1006 apic_write(APIC_LVT1, value);
1010 void __cpuinit end_local_APIC_setup(void)
1013 setup_apic_nmi_watchdog(NULL);
1017 void check_x2apic(void)
1021 rdmsr(MSR_IA32_APICBASE, msr, msr2);
1023 if (msr & X2APIC_ENABLE) {
1024 printk("x2apic enabled by BIOS, switching to x2apic ops\n");
1025 x2apic_preenabled = x2apic = 1;
1026 apic_ops = &x2apic_ops;
1030 void enable_x2apic(void)
1034 rdmsr(MSR_IA32_APICBASE, msr, msr2);
1035 if (!(msr & X2APIC_ENABLE)) {
1036 printk("Enabling x2apic\n");
1037 wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
1041 void enable_IR_x2apic(void)
1043 #ifdef CONFIG_INTR_REMAP
1045 unsigned long flags;
1047 if (!cpu_has_x2apic)
1050 if (!x2apic_preenabled && disable_x2apic) {
1052 "Skipped enabling x2apic and Interrupt-remapping "
1053 "because of nox2apic\n");
1057 if (x2apic_preenabled && disable_x2apic)
1058 panic("Bios already enabled x2apic, can't enforce nox2apic");
1060 if (!x2apic_preenabled && skip_ioapic_setup) {
1062 "Skipped enabling x2apic and Interrupt-remapping "
1063 "because of skipping io-apic setup\n");
1067 ret = dmar_table_init();
1070 "dmar_table_init() failed with %d:\n", ret);
1072 if (x2apic_preenabled)
1073 panic("x2apic enabled by bios. But IR enabling failed");
1076 "Not enabling x2apic,Intr-remapping\n");
1080 local_irq_save(flags);
1082 save_mask_IO_APIC_setup();
1084 ret = enable_intr_remapping(1);
1086 if (ret && x2apic_preenabled) {
1087 local_irq_restore(flags);
1088 panic("x2apic enabled by bios. But IR enabling failed");
1096 apic_ops = &x2apic_ops;
1102 * IR enabling failed
1104 restore_IO_APIC_setup();
1106 reinit_intr_remapped_IO_APIC(x2apic_preenabled);
1109 local_irq_restore(flags);
1112 if (!x2apic_preenabled)
1114 "Enabled x2apic and interrupt-remapping\n");
1117 "Enabled Interrupt-remapping\n");
1120 "Failed to enable Interrupt-remapping and x2apic\n");
1122 if (!cpu_has_x2apic)
1125 if (x2apic_preenabled)
1126 panic("x2apic enabled prior OS handover,"
1127 " enable CONFIG_INTR_REMAP");
1129 printk(KERN_INFO "Enable CONFIG_INTR_REMAP for enabling intr-remapping "
1137 * Detect and enable local APICs on non-SMP boards.
1138 * Original code written by Keir Fraser.
1139 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1140 * not correctly set up (usually the APIC timer won't work etc.)
1142 static int __init detect_init_APIC(void)
1144 if (!cpu_has_apic) {
1145 printk(KERN_INFO "No local APIC present\n");
1149 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1150 boot_cpu_physical_apicid = 0;
1154 void __init early_init_lapic_mapping(void)
1156 unsigned long phys_addr;
1159 * If no local APIC can be found then go out
1160 * : it means there is no mpatable and MADT
1162 if (!smp_found_config)
1165 phys_addr = mp_lapic_addr;
1167 set_fixmap_nocache(FIX_APIC_BASE, phys_addr);
1168 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1169 APIC_BASE, phys_addr);
1172 * Fetch the APIC ID of the BSP in case we have a
1173 * default configuration (or the MP table is broken).
1175 boot_cpu_physical_apicid = read_apic_id();
1179 * init_apic_mappings - initialize APIC mappings
1181 void __init init_apic_mappings(void)
1184 boot_cpu_physical_apicid = read_apic_id();
1189 * If no local APIC can be found then set up a fake all
1190 * zeroes page to simulate the local APIC and another
1191 * one for the IO-APIC.
1193 if (!smp_found_config && detect_init_APIC()) {
1194 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
1195 apic_phys = __pa(apic_phys);
1197 apic_phys = mp_lapic_addr;
1199 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
1200 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1201 APIC_BASE, apic_phys);
1204 * Fetch the APIC ID of the BSP in case we have a
1205 * default configuration (or the MP table is broken).
1207 boot_cpu_physical_apicid = read_apic_id();
1211 * This initializes the IO-APIC and APIC hardware if this is
1214 int __init APIC_init_uniprocessor(void)
1217 printk(KERN_INFO "Apic disabled\n");
1220 if (!cpu_has_apic) {
1222 printk(KERN_INFO "Apic disabled by BIOS\n");
1227 setup_apic_routing();
1229 verify_local_APIC();
1233 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1234 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1239 * Now enable IO-APICs, actually call clear_IO_APIC
1240 * We need clear_IO_APIC before enabling vector on BP
1242 if (!skip_ioapic_setup && nr_ioapics)
1245 if (!smp_found_config || skip_ioapic_setup || !nr_ioapics)
1246 localise_nmi_watchdog();
1247 end_local_APIC_setup();
1249 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1253 setup_boot_APIC_clock();
1254 check_nmi_watchdog();
1259 * Local APIC interrupts
1263 * This interrupt should _never_ happen with our APIC/SMP architecture
1265 asmlinkage void smp_spurious_interrupt(void)
1271 * Check if this really is a spurious interrupt and ACK it
1272 * if it is a vectored one. Just in case...
1273 * Spurious interrupts should not be ACKed.
1275 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1276 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1279 add_pda(irq_spurious_count, 1);
1284 * This interrupt should never happen with our APIC/SMP architecture
1286 asmlinkage void smp_error_interrupt(void)
1292 /* First tickle the hardware, only then report what went on. -- REW */
1293 v = apic_read(APIC_ESR);
1294 apic_write(APIC_ESR, 0);
1295 v1 = apic_read(APIC_ESR);
1297 atomic_inc(&irq_err_count);
1299 /* Here is what the APIC error bits mean:
1302 2: Send accept error
1303 3: Receive accept error
1305 5: Send illegal vector
1306 6: Received illegal vector
1307 7: Illegal register address
1309 printk(KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1310 smp_processor_id(), v , v1);
1315 * connect_bsp_APIC - attach the APIC to the interrupt system
1317 void __init connect_bsp_APIC(void)
1319 #ifdef CONFIG_X86_32
1322 * Do not trust the local APIC being empty at bootup.
1326 * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
1327 * local APIC to INT and NMI lines.
1329 apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1330 "enabling APIC mode.\n");
1339 * disconnect_bsp_APIC - detach the APIC from the interrupt system
1340 * @virt_wire_setup: indicates, whether virtual wire mode is selected
1342 * Virtual wire mode is necessary to deliver legacy interrupts even when the
1345 void disconnect_bsp_APIC(int virt_wire_setup)
1347 /* Go back to Virtual Wire compatibility mode */
1348 unsigned long value;
1350 /* For the spurious interrupt use vector F, and enable it */
1351 value = apic_read(APIC_SPIV);
1352 value &= ~APIC_VECTOR_MASK;
1353 value |= APIC_SPIV_APIC_ENABLED;
1355 apic_write(APIC_SPIV, value);
1357 if (!virt_wire_setup) {
1359 * For LVT0 make it edge triggered, active high,
1360 * external and enabled
1362 value = apic_read(APIC_LVT0);
1363 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1364 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1365 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1366 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1367 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1368 apic_write(APIC_LVT0, value);
1371 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1374 /* For LVT1 make it edge triggered, active high, nmi and enabled */
1375 value = apic_read(APIC_LVT1);
1376 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1377 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1378 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1379 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1380 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1381 apic_write(APIC_LVT1, value);
1384 void __cpuinit generic_processor_info(int apicid, int version)
1389 if (num_processors >= NR_CPUS) {
1390 printk(KERN_WARNING "WARNING: NR_CPUS limit of %i reached."
1391 " Processor ignored.\n", NR_CPUS);
1395 if (num_processors >= maxcpus) {
1396 printk(KERN_WARNING "WARNING: maxcpus limit of %i reached."
1397 " Processor ignored.\n", maxcpus);
1402 cpus_complement(tmp_map, cpu_present_map);
1403 cpu = first_cpu(tmp_map);
1405 physid_set(apicid, phys_cpu_present_map);
1406 if (apicid == boot_cpu_physical_apicid) {
1408 * x86_bios_cpu_apicid is required to have processors listed
1409 * in same order as logical cpu numbers. Hence the first
1410 * entry is BSP, and so on.
1414 if (apicid > max_physical_apicid)
1415 max_physical_apicid = apicid;
1417 /* are we being called early in kernel startup? */
1418 if (early_per_cpu_ptr(x86_cpu_to_apicid)) {
1419 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
1420 u16 *bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
1422 cpu_to_apicid[cpu] = apicid;
1423 bios_cpu_apicid[cpu] = apicid;
1425 per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1426 per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1429 cpu_set(cpu, cpu_possible_map);
1430 cpu_set(cpu, cpu_present_map);
1433 int hard_smp_processor_id(void)
1435 return read_apic_id();
1445 * 'active' is true if the local APIC was enabled by us and
1446 * not the BIOS; this signifies that we are also responsible
1447 * for disabling it before entering apm/acpi suspend
1450 /* r/w apic fields */
1451 unsigned int apic_id;
1452 unsigned int apic_taskpri;
1453 unsigned int apic_ldr;
1454 unsigned int apic_dfr;
1455 unsigned int apic_spiv;
1456 unsigned int apic_lvtt;
1457 unsigned int apic_lvtpc;
1458 unsigned int apic_lvt0;
1459 unsigned int apic_lvt1;
1460 unsigned int apic_lvterr;
1461 unsigned int apic_tmict;
1462 unsigned int apic_tdcr;
1463 unsigned int apic_thmr;
1466 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1468 unsigned long flags;
1471 if (!apic_pm_state.active)
1474 maxlvt = lapic_get_maxlvt();
1476 apic_pm_state.apic_id = apic_read(APIC_ID);
1477 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1478 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1479 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1480 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
1481 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
1483 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
1484 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
1485 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
1486 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
1487 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
1488 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
1489 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
1491 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
1494 local_irq_save(flags);
1495 disable_local_APIC();
1496 local_irq_restore(flags);
1500 static int lapic_resume(struct sys_device *dev)
1503 unsigned long flags;
1506 if (!apic_pm_state.active)
1509 maxlvt = lapic_get_maxlvt();
1511 local_irq_save(flags);
1513 #ifdef CONFIG_X86_64
1520 * Make sure the APICBASE points to the right address
1522 * FIXME! This will be wrong if we ever support suspend on
1523 * SMP! We'll need to do this as part of the CPU restore!
1525 rdmsr(MSR_IA32_APICBASE, l, h);
1526 l &= ~MSR_IA32_APICBASE_BASE;
1527 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
1528 wrmsr(MSR_IA32_APICBASE, l, h);
1531 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
1532 apic_write(APIC_ID, apic_pm_state.apic_id);
1533 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
1534 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
1535 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
1536 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
1537 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
1538 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
1539 #if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
1541 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
1544 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
1545 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
1546 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
1547 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
1548 apic_write(APIC_ESR, 0);
1549 apic_read(APIC_ESR);
1550 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
1551 apic_write(APIC_ESR, 0);
1552 apic_read(APIC_ESR);
1554 local_irq_restore(flags);
1560 * This device has no shutdown method - fully functioning local APICs
1561 * are needed on every CPU up until machine_halt/restart/poweroff.
1564 static struct sysdev_class lapic_sysclass = {
1566 .resume = lapic_resume,
1567 .suspend = lapic_suspend,
1570 static struct sys_device device_lapic = {
1572 .cls = &lapic_sysclass,
1575 static void __cpuinit apic_pm_activate(void)
1577 apic_pm_state.active = 1;
1580 static int __init init_lapic_sysfs(void)
1586 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
1588 error = sysdev_class_register(&lapic_sysclass);
1590 error = sysdev_register(&device_lapic);
1593 device_initcall(init_lapic_sysfs);
1595 #else /* CONFIG_PM */
1597 static void apic_pm_activate(void) { }
1599 #endif /* CONFIG_PM */
1602 * apic_is_clustered_box() -- Check if we can expect good TSC
1604 * Thus far, the major user of this is IBM's Summit2 series:
1606 * Clustered boxes may have unsynced TSC problems if they are
1607 * multi-chassis. Use available data to take a good guess.
1608 * If in doubt, go HPET.
1610 __cpuinit int apic_is_clustered_box(void)
1612 int i, clusters, zeros;
1614 u16 *bios_cpu_apicid;
1615 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
1618 * there is not this kind of box with AMD CPU yet.
1619 * Some AMD box with quadcore cpu and 8 sockets apicid
1620 * will be [4, 0x23] or [8, 0x27] could be thought to
1621 * vsmp box still need checking...
1623 if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && !is_vsmp_box())
1626 bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
1627 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
1629 for (i = 0; i < NR_CPUS; i++) {
1630 /* are we being called early in kernel startup? */
1631 if (bios_cpu_apicid) {
1632 id = bios_cpu_apicid[i];
1634 else if (i < nr_cpu_ids) {
1636 id = per_cpu(x86_bios_cpu_apicid, i);
1643 if (id != BAD_APICID)
1644 __set_bit(APIC_CLUSTERID(id), clustermap);
1647 /* Problem: Partially populated chassis may not have CPUs in some of
1648 * the APIC clusters they have been allocated. Only present CPUs have
1649 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
1650 * Since clusters are allocated sequentially, count zeros only if
1651 * they are bounded by ones.
1655 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
1656 if (test_bit(i, clustermap)) {
1657 clusters += 1 + zeros;
1663 /* ScaleMP vSMPowered boxes have one cluster per board and TSCs are
1664 * not guaranteed to be synced between boards
1666 if (is_vsmp_box() && clusters > 1)
1670 * If clusters > 2, then should be multi-chassis.
1671 * May have to revisit this when multi-core + hyperthreaded CPUs come
1672 * out, but AFAIK this will work even for them.
1674 return (clusters > 2);
1677 static __init int setup_nox2apic(char *str)
1680 clear_cpu_cap(&boot_cpu_data, X86_FEATURE_X2APIC);
1683 early_param("nox2apic", setup_nox2apic);
1687 * APIC command line parameters
1689 static int __init apic_set_verbosity(char *str)
1692 skip_ioapic_setup = 0;
1696 if (strcmp("debug", str) == 0)
1697 apic_verbosity = APIC_DEBUG;
1698 else if (strcmp("verbose", str) == 0)
1699 apic_verbosity = APIC_VERBOSE;
1701 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
1702 " use apic=verbose or apic=debug\n", str);
1708 early_param("apic", apic_set_verbosity);
1710 static __init int setup_disableapic(char *str)
1713 setup_clear_cpu_cap(X86_FEATURE_APIC);
1716 early_param("disableapic", setup_disableapic);
1718 /* same as disableapic, for compatibility */
1719 static __init int setup_nolapic(char *str)
1721 return setup_disableapic(str);
1723 early_param("nolapic", setup_nolapic);
1725 static int __init parse_lapic_timer_c2_ok(char *arg)
1727 local_apic_timer_c2_ok = 1;
1730 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
1732 static int __init parse_disable_apic_timer(char *arg)
1734 disable_apic_timer = 1;
1737 early_param("noapictimer", parse_disable_apic_timer);
1739 static int __init parse_nolapic_timer(char *arg)
1741 disable_apic_timer = 1;
1744 early_param("nolapic_timer", parse_nolapic_timer);
1746 static __init int setup_apicpmtimer(char *s)
1748 apic_calibrate_pmtmr = 1;
1752 __setup("apicpmtimer", setup_apicpmtimer);
1754 static int __init lapic_insert_resource(void)
1759 /* Put local APIC into the resource map. */
1760 lapic_resource.start = apic_phys;
1761 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
1762 insert_resource(&iomem_resource, &lapic_resource);
1768 * need call insert after e820_reserve_resources()
1769 * that is using request_resource
1771 late_initcall(lapic_insert_resource);