1 // SPDX-License-Identifier: GPL-2.0-only
3 * Local APIC handling, local APIC timers
5 * (c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
8 * Maciej W. Rozycki : Bits for genuine 82489DX APICs;
9 * thanks to Eric Gilmore
11 * for testing these extensively.
12 * Maciej W. Rozycki : Various updates and fixes.
13 * Mikael Pettersson : Power Management for UP-APIC.
15 * Mikael Pettersson : PM converted to driver model.
18 #include <linux/perf_event.h>
19 #include <linux/kernel_stat.h>
20 #include <linux/mc146818rtc.h>
21 #include <linux/acpi_pmtmr.h>
22 #include <linux/clockchips.h>
23 #include <linux/interrupt.h>
24 #include <linux/memblock.h>
25 #include <linux/ftrace.h>
26 #include <linux/ioport.h>
27 #include <linux/export.h>
28 #include <linux/syscore_ops.h>
29 #include <linux/delay.h>
30 #include <linux/timex.h>
31 #include <linux/i8253.h>
32 #include <linux/dmar.h>
33 #include <linux/init.h>
34 #include <linux/cpu.h>
35 #include <linux/dmi.h>
36 #include <linux/smp.h>
39 #include <asm/trace/irq_vectors.h>
40 #include <asm/irq_remapping.h>
41 #include <asm/pc-conf-reg.h>
42 #include <asm/perf_event.h>
43 #include <asm/x86_init.h>
44 #include <linux/atomic.h>
45 #include <asm/barrier.h>
46 #include <asm/mpspec.h>
47 #include <asm/i8259.h>
48 #include <asm/proto.h>
49 #include <asm/traps.h>
52 #include <asm/io_apic.h>
60 #include <asm/hypervisor.h>
61 #include <asm/cpu_device_id.h>
62 #include <asm/intel-family.h>
63 #include <asm/irq_regs.h>
65 unsigned int num_processors;
67 unsigned disabled_cpus;
69 /* Processor that is doing the boot up */
70 unsigned int boot_cpu_physical_apicid __ro_after_init = -1U;
71 EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
73 u8 boot_cpu_apic_version __ro_after_init;
76 * The highest APIC ID seen during enumeration.
78 static unsigned int max_physical_apicid;
81 * Bitmask of physically existing CPUs:
83 physid_mask_t phys_cpu_present_map;
86 * Processor to be disabled specified by kernel parameter
87 * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
88 * avoid undefined behaviour caused by sending INIT from AP to BSP.
90 static unsigned int disabled_cpu_apicid __ro_after_init = BAD_APICID;
93 * This variable controls which CPUs receive external NMIs. By default,
94 * external NMIs are delivered only to the BSP.
96 static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;
99 * Hypervisor supports 15 bits of APIC ID in MSI Extended Destination ID
101 static bool virt_ext_dest_id __ro_after_init;
104 * Map cpu index to physical APIC ID
106 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID);
107 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID);
108 DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX);
109 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
110 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
111 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid);
116 * On x86_32, the mapping between cpu and logical apicid may vary
117 * depending on apic in use. The following early percpu variable is
118 * used for the mapping. This is where the behaviors of x86_64 and 32
119 * actually diverge. Let's keep it ugly for now.
121 DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);
123 /* Local APIC was disabled by the BIOS and enabled by the kernel */
124 static int enabled_via_apicbase __ro_after_init;
127 * Handle interrupt mode configuration register (IMCR).
128 * This register controls whether the interrupt signals
129 * that reach the BSP come from the master PIC or from the
130 * local APIC. Before entering Symmetric I/O Mode, either
131 * the BIOS or the operating system must switch out of
132 * PIC Mode by changing the IMCR.
134 static inline void imcr_pic_to_apic(void)
136 /* NMI and 8259 INTR go through APIC */
137 pc_conf_set(PC_CONF_MPS_IMCR, 0x01);
140 static inline void imcr_apic_to_pic(void)
142 /* NMI and 8259 INTR go directly to BSP */
143 pc_conf_set(PC_CONF_MPS_IMCR, 0x00);
148 * Knob to control our willingness to enable the local APIC.
152 static int force_enable_local_apic __initdata;
155 * APIC command line parameters
157 static int __init parse_lapic(char *arg)
159 if (IS_ENABLED(CONFIG_X86_32) && !arg)
160 force_enable_local_apic = 1;
161 else if (arg && !strncmp(arg, "notscdeadline", 13))
162 setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
165 early_param("lapic", parse_lapic);
168 static int apic_calibrate_pmtmr __initdata;
169 static __init int setup_apicpmtimer(char *s)
171 apic_calibrate_pmtmr = 1;
175 __setup("apicpmtimer", setup_apicpmtimer);
178 unsigned long mp_lapic_addr __ro_after_init;
179 int disable_apic __ro_after_init;
180 /* Disable local APIC timer from the kernel commandline or via dmi quirk */
181 static int disable_apic_timer __initdata;
182 /* Local APIC timer works in C2 */
183 int local_apic_timer_c2_ok __ro_after_init;
184 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
187 * Debug level, exported for io_apic.c
189 int apic_verbosity __ro_after_init;
191 int pic_mode __ro_after_init;
193 /* Have we found an MP table */
194 int smp_found_config __ro_after_init;
196 static struct resource lapic_resource = {
197 .name = "Local APIC",
198 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
201 unsigned int lapic_timer_period = 0;
203 static void apic_pm_activate(void);
205 static unsigned long apic_phys __ro_after_init;
208 * Get the LAPIC version
210 static inline int lapic_get_version(void)
212 return GET_APIC_VERSION(apic_read(APIC_LVR));
216 * Check, if the APIC is integrated or a separate chip
218 static inline int lapic_is_integrated(void)
220 return APIC_INTEGRATED(lapic_get_version());
224 * Check, whether this is a modern or a first generation APIC
226 static int modern_apic(void)
228 /* AMD systems use old APIC versions, so check the CPU */
229 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
230 boot_cpu_data.x86 >= 0xf)
233 /* Hygon systems use modern APIC */
234 if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
237 return lapic_get_version() >= 0x14;
241 * right after this call apic become NOOP driven
242 * so apic->write/read doesn't do anything
244 static void __init apic_disable(void)
246 pr_info("APIC: switched to apic NOOP\n");
250 void native_apic_wait_icr_idle(void)
252 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
256 u32 native_safe_apic_wait_icr_idle(void)
263 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
266 inc_irq_stat(icr_read_retry_count);
268 } while (timeout++ < 1000);
273 void native_apic_icr_write(u32 low, u32 id)
277 local_irq_save(flags);
278 apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
279 apic_write(APIC_ICR, low);
280 local_irq_restore(flags);
283 u64 native_apic_icr_read(void)
287 icr2 = apic_read(APIC_ICR2);
288 icr1 = apic_read(APIC_ICR);
290 return icr1 | ((u64)icr2 << 32);
295 * get_physical_broadcast - Get number of physical broadcast IDs
297 int get_physical_broadcast(void)
299 return modern_apic() ? 0xff : 0xf;
304 * lapic_get_maxlvt - get the maximum number of local vector table entries
306 int lapic_get_maxlvt(void)
309 * - we always have APIC integrated on 64bit mode
310 * - 82489DXs do not report # of LVT entries
312 return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
320 #define APIC_DIVISOR 16
321 #define TSC_DIVISOR 8
324 * This function sets up the local APIC timer, with a timeout of
325 * 'clocks' APIC bus clock. During calibration we actually call
326 * this function twice on the boot CPU, once with a bogus timeout
327 * value, second time for real. The other (noncalibrating) CPUs
328 * call this function only once, with the real, calibrated value.
330 * We do reads before writes even if unnecessary, to get around the
331 * P5 APIC double write bug.
333 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
335 unsigned int lvtt_value, tmp_value;
337 lvtt_value = LOCAL_TIMER_VECTOR;
339 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
340 else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
341 lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE;
343 if (!lapic_is_integrated())
344 lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
347 lvtt_value |= APIC_LVT_MASKED;
349 apic_write(APIC_LVTT, lvtt_value);
351 if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
353 * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
354 * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
355 * According to Intel, MFENCE can do the serialization here.
357 asm volatile("mfence" : : : "memory");
364 tmp_value = apic_read(APIC_TDCR);
365 apic_write(APIC_TDCR,
366 (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
370 apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
374 * Setup extended LVT, AMD specific
376 * Software should use the LVT offsets the BIOS provides. The offsets
377 * are determined by the subsystems using it like those for MCE
378 * threshold or IBS. On K8 only offset 0 (APIC500) and MCE interrupts
379 * are supported. Beginning with family 10h at least 4 offsets are
382 * Since the offsets must be consistent for all cores, we keep track
383 * of the LVT offsets in software and reserve the offset for the same
384 * vector also to be used on other cores. An offset is freed by
385 * setting the entry to APIC_EILVT_MASKED.
387 * If the BIOS is right, there should be no conflicts. Otherwise a
388 * "[Firmware Bug]: ..." error message is generated. However, if
389 * software does not properly determines the offsets, it is not
390 * necessarily a BIOS bug.
393 static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
395 static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
397 return (old & APIC_EILVT_MASKED)
398 || (new == APIC_EILVT_MASKED)
399 || ((new & ~APIC_EILVT_MASKED) == old);
402 static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
404 unsigned int rsvd, vector;
406 if (offset >= APIC_EILVT_NR_MAX)
409 rsvd = atomic_read(&eilvt_offsets[offset]);
411 vector = rsvd & ~APIC_EILVT_MASKED; /* 0: unassigned */
412 if (vector && !eilvt_entry_is_changeable(vector, new))
413 /* may not change if vectors are different */
415 rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
416 } while (rsvd != new);
418 rsvd &= ~APIC_EILVT_MASKED;
419 if (rsvd && rsvd != vector)
420 pr_info("LVT offset %d assigned for vector 0x%02x\n",
427 * If mask=1, the LVT entry does not generate interrupts while mask=0
428 * enables the vector. See also the BKDGs. Must be called with
429 * preemption disabled.
432 int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
434 unsigned long reg = APIC_EILVTn(offset);
435 unsigned int new, old, reserved;
437 new = (mask << 16) | (msg_type << 8) | vector;
438 old = apic_read(reg);
439 reserved = reserve_eilvt_offset(offset, new);
441 if (reserved != new) {
442 pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
443 "vector 0x%x, but the register is already in use for "
444 "vector 0x%x on another cpu\n",
445 smp_processor_id(), reg, offset, new, reserved);
449 if (!eilvt_entry_is_changeable(old, new)) {
450 pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
451 "vector 0x%x, but the register is already in use for "
452 "vector 0x%x on this cpu\n",
453 smp_processor_id(), reg, offset, new, old);
457 apic_write(reg, new);
461 EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
464 * Program the next event, relative to now
466 static int lapic_next_event(unsigned long delta,
467 struct clock_event_device *evt)
469 apic_write(APIC_TMICT, delta);
473 static int lapic_next_deadline(unsigned long delta,
474 struct clock_event_device *evt)
478 /* This MSR is special and need a special fence: */
482 wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
486 static int lapic_timer_shutdown(struct clock_event_device *evt)
490 /* Lapic used as dummy for broadcast ? */
491 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
494 v = apic_read(APIC_LVTT);
495 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
496 apic_write(APIC_LVTT, v);
497 apic_write(APIC_TMICT, 0);
502 lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot)
504 /* Lapic used as dummy for broadcast ? */
505 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
508 __setup_APIC_LVTT(lapic_timer_period, oneshot, 1);
512 static int lapic_timer_set_periodic(struct clock_event_device *evt)
514 return lapic_timer_set_periodic_oneshot(evt, false);
517 static int lapic_timer_set_oneshot(struct clock_event_device *evt)
519 return lapic_timer_set_periodic_oneshot(evt, true);
523 * Local APIC timer broadcast function
525 static void lapic_timer_broadcast(const struct cpumask *mask)
528 apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
534 * The local apic timer can be used for any function which is CPU local.
536 static struct clock_event_device lapic_clockevent = {
538 .features = CLOCK_EVT_FEAT_PERIODIC |
539 CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
540 | CLOCK_EVT_FEAT_DUMMY,
542 .set_state_shutdown = lapic_timer_shutdown,
543 .set_state_periodic = lapic_timer_set_periodic,
544 .set_state_oneshot = lapic_timer_set_oneshot,
545 .set_state_oneshot_stopped = lapic_timer_shutdown,
546 .set_next_event = lapic_next_event,
547 .broadcast = lapic_timer_broadcast,
551 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
553 static const struct x86_cpu_id deadline_match[] __initconst = {
554 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x2, 0x2), 0x3a), /* EP */
555 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x4, 0x4), 0x0f), /* EX */
557 X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X, 0x0b000020),
559 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x2, 0x2), 0x00000011),
560 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x3, 0x3), 0x0700000e),
561 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x4, 0x4), 0x0f00000c),
562 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x5, 0x5), 0x0e000003),
564 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x3, 0x3), 0x01000136),
565 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x4, 0x4), 0x02000014),
566 X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x5, 0xf), 0),
568 X86_MATCH_INTEL_FAM6_MODEL( HASWELL, 0x22),
569 X86_MATCH_INTEL_FAM6_MODEL( HASWELL_L, 0x20),
570 X86_MATCH_INTEL_FAM6_MODEL( HASWELL_G, 0x17),
572 X86_MATCH_INTEL_FAM6_MODEL( BROADWELL, 0x25),
573 X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_G, 0x17),
575 X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE_L, 0xb2),
576 X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE, 0xb2),
578 X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE_L, 0x52),
579 X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE, 0x52),
584 static __init bool apic_validate_deadline_timer(void)
586 const struct x86_cpu_id *m;
589 if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
591 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
594 m = x86_match_cpu(deadline_match);
598 rev = (u32)m->driver_data;
600 if (boot_cpu_data.microcode >= rev)
603 setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
604 pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
605 "please update microcode to version: 0x%x (or later)\n", rev);
610 * Setup the local APIC timer for this CPU. Copy the initialized values
611 * of the boot CPU and register the clock event in the framework.
613 static void setup_APIC_timer(void)
615 struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
617 if (this_cpu_has(X86_FEATURE_ARAT)) {
618 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
619 /* Make LAPIC timer preferable over percpu HPET */
620 lapic_clockevent.rating = 150;
623 memcpy(levt, &lapic_clockevent, sizeof(*levt));
624 levt->cpumask = cpumask_of(smp_processor_id());
626 if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) {
627 levt->name = "lapic-deadline";
628 levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC |
629 CLOCK_EVT_FEAT_DUMMY);
630 levt->set_next_event = lapic_next_deadline;
631 clockevents_config_and_register(levt,
632 tsc_khz * (1000 / TSC_DIVISOR),
635 clockevents_register_device(levt);
639 * Install the updated TSC frequency from recalibration at the TSC
640 * deadline clockevent devices.
642 static void __lapic_update_tsc_freq(void *info)
644 struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
646 if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
649 clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR));
652 void lapic_update_tsc_freq(void)
655 * The clockevent device's ->mult and ->shift can both be
656 * changed. In order to avoid races, schedule the frequency
657 * update code on each CPU.
659 on_each_cpu(__lapic_update_tsc_freq, NULL, 0);
663 * In this functions we calibrate APIC bus clocks to the external timer.
665 * We want to do the calibration only once since we want to have local timer
666 * irqs synchronous. CPUs connected by the same APIC bus have the very same bus
669 * This was previously done by reading the PIT/HPET and waiting for a wrap
670 * around to find out, that a tick has elapsed. I have a box, where the PIT
671 * readout is broken, so it never gets out of the wait loop again. This was
672 * also reported by others.
674 * Monitoring the jiffies value is inaccurate and the clockevents
675 * infrastructure allows us to do a simple substitution of the interrupt
678 * The calibration routine also uses the pm_timer when possible, as the PIT
679 * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
680 * back to normal later in the boot process).
683 #define LAPIC_CAL_LOOPS (HZ/10)
685 static __initdata int lapic_cal_loops = -1;
686 static __initdata long lapic_cal_t1, lapic_cal_t2;
687 static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
688 static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
689 static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
692 * Temporary interrupt handler and polled calibration function.
694 static void __init lapic_cal_handler(struct clock_event_device *dev)
696 unsigned long long tsc = 0;
697 long tapic = apic_read(APIC_TMCCT);
698 unsigned long pm = acpi_pm_read_early();
700 if (boot_cpu_has(X86_FEATURE_TSC))
703 switch (lapic_cal_loops++) {
705 lapic_cal_t1 = tapic;
706 lapic_cal_tsc1 = tsc;
708 lapic_cal_j1 = jiffies;
711 case LAPIC_CAL_LOOPS:
712 lapic_cal_t2 = tapic;
713 lapic_cal_tsc2 = tsc;
714 if (pm < lapic_cal_pm1)
715 pm += ACPI_PM_OVRRUN;
717 lapic_cal_j2 = jiffies;
723 calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
725 const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
726 const long pm_thresh = pm_100ms / 100;
730 #ifndef CONFIG_X86_PM_TIMER
734 apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
736 /* Check, if the PM timer is available */
740 mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
742 if (deltapm > (pm_100ms - pm_thresh) &&
743 deltapm < (pm_100ms + pm_thresh)) {
744 apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
748 res = (((u64)deltapm) * mult) >> 22;
749 do_div(res, 1000000);
750 pr_warn("APIC calibration not consistent "
751 "with PM-Timer: %ldms instead of 100ms\n", (long)res);
753 /* Correct the lapic counter value */
754 res = (((u64)(*delta)) * pm_100ms);
755 do_div(res, deltapm);
756 pr_info("APIC delta adjusted to PM-Timer: "
757 "%lu (%ld)\n", (unsigned long)res, *delta);
760 /* Correct the tsc counter value */
761 if (boot_cpu_has(X86_FEATURE_TSC)) {
762 res = (((u64)(*deltatsc)) * pm_100ms);
763 do_div(res, deltapm);
764 apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
765 "PM-Timer: %lu (%ld)\n",
766 (unsigned long)res, *deltatsc);
767 *deltatsc = (long)res;
773 static int __init lapic_init_clockevent(void)
775 if (!lapic_timer_period)
778 /* Calculate the scaled math multiplication factor */
779 lapic_clockevent.mult = div_sc(lapic_timer_period/APIC_DIVISOR,
780 TICK_NSEC, lapic_clockevent.shift);
781 lapic_clockevent.max_delta_ns =
782 clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
783 lapic_clockevent.max_delta_ticks = 0x7FFFFFFF;
784 lapic_clockevent.min_delta_ns =
785 clockevent_delta2ns(0xF, &lapic_clockevent);
786 lapic_clockevent.min_delta_ticks = 0xF;
791 bool __init apic_needs_pit(void)
794 * If the frequencies are not known, PIT is required for both TSC
795 * and apic timer calibration.
797 if (!tsc_khz || !cpu_khz)
800 /* Is there an APIC at all or is it disabled? */
801 if (!boot_cpu_has(X86_FEATURE_APIC) || disable_apic)
805 * If interrupt delivery mode is legacy PIC or virtual wire without
806 * configuration, the local APIC timer wont be set up. Make sure
807 * that the PIT is initialized.
809 if (apic_intr_mode == APIC_PIC ||
810 apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG)
813 /* Virt guests may lack ARAT, but still have DEADLINE */
814 if (!boot_cpu_has(X86_FEATURE_ARAT))
817 /* Deadline timer is based on TSC so no further PIT action required */
818 if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
821 /* APIC timer disabled? */
822 if (disable_apic_timer)
825 * The APIC timer frequency is known already, no PIT calibration
826 * required. If unknown, let the PIT be initialized.
828 return lapic_timer_period == 0;
831 static int __init calibrate_APIC_clock(void)
833 struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
834 u64 tsc_perj = 0, tsc_start = 0;
835 unsigned long jif_start;
836 unsigned long deltaj;
837 long delta, deltatsc;
838 int pm_referenced = 0;
840 if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
844 * Check if lapic timer has already been calibrated by platform
845 * specific routine, such as tsc calibration code. If so just fill
846 * in the clockevent structure and return.
848 if (!lapic_init_clockevent()) {
849 apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
852 * Direct calibration methods must have an always running
853 * local APIC timer, no need for broadcast timer.
855 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
859 apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
860 "calibrating APIC timer ...\n");
863 * There are platforms w/o global clockevent devices. Instead of
864 * making the calibration conditional on that, use a polling based
865 * approach everywhere.
870 * Setup the APIC counter to maximum. There is no way the lapic
871 * can underflow in the 100ms detection time frame
873 __setup_APIC_LVTT(0xffffffff, 0, 0);
876 * Methods to terminate the calibration loop:
877 * 1) Global clockevent if available (jiffies)
878 * 2) TSC if available and frequency is known
880 jif_start = READ_ONCE(jiffies);
884 tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
888 * Enable interrupts so the tick can fire, if a global
889 * clockevent device is available
893 while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
894 /* Wait for a tick to elapse */
897 u64 tsc_now = rdtsc();
898 if ((tsc_now - tsc_start) >= tsc_perj) {
899 tsc_start += tsc_perj;
903 unsigned long jif_now = READ_ONCE(jiffies);
905 if (time_after(jif_now, jif_start)) {
913 /* Invoke the calibration routine */
915 lapic_cal_handler(NULL);
921 /* Build delta t1-t2 as apic timer counts down */
922 delta = lapic_cal_t1 - lapic_cal_t2;
923 apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
925 deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
927 /* we trust the PM based calibration if possible */
928 pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
931 lapic_timer_period = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
932 lapic_init_clockevent();
934 apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
935 apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
936 apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
939 if (boot_cpu_has(X86_FEATURE_TSC)) {
940 apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
942 (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
943 (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
946 apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
948 lapic_timer_period / (1000000 / HZ),
949 lapic_timer_period % (1000000 / HZ));
952 * Do a sanity check on the APIC calibration result
954 if (lapic_timer_period < (1000000 / HZ)) {
956 pr_warn("APIC frequency too slow, disabling apic timer\n");
960 levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
963 * PM timer calibration failed or not turned on so lets try APIC
964 * timer based calibration, if a global clockevent device is
967 if (!pm_referenced && global_clock_event) {
968 apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
971 * Setup the apic timer manually
973 levt->event_handler = lapic_cal_handler;
974 lapic_timer_set_periodic(levt);
975 lapic_cal_loops = -1;
977 /* Let the interrupts run */
980 while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
983 /* Stop the lapic timer */
985 lapic_timer_shutdown(levt);
988 deltaj = lapic_cal_j2 - lapic_cal_j1;
989 apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
991 /* Check, if the jiffies result is consistent */
992 if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
993 apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
995 levt->features |= CLOCK_EVT_FEAT_DUMMY;
999 if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
1000 pr_warn("APIC timer disabled due to verification failure\n");
1008 * Setup the boot APIC
1010 * Calibrate and verify the result.
1012 void __init setup_boot_APIC_clock(void)
1015 * The local apic timer can be disabled via the kernel
1016 * commandline or from the CPU detection code. Register the lapic
1017 * timer as a dummy clock event source on SMP systems, so the
1018 * broadcast mechanism is used. On UP systems simply ignore it.
1020 if (disable_apic_timer) {
1021 pr_info("Disabling APIC timer\n");
1022 /* No broadcast on UP ! */
1023 if (num_possible_cpus() > 1) {
1024 lapic_clockevent.mult = 1;
1030 if (calibrate_APIC_clock()) {
1031 /* No broadcast on UP ! */
1032 if (num_possible_cpus() > 1)
1038 * If nmi_watchdog is set to IO_APIC, we need the
1039 * PIT/HPET going. Otherwise register lapic as a dummy
1042 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
1044 /* Setup the lapic or request the broadcast */
1046 amd_e400_c1e_apic_setup();
1049 void setup_secondary_APIC_clock(void)
1052 amd_e400_c1e_apic_setup();
1056 * The guts of the apic timer interrupt
1058 static void local_apic_timer_interrupt(void)
1060 struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
1063 * Normally we should not be here till LAPIC has been initialized but
1064 * in some cases like kdump, its possible that there is a pending LAPIC
1065 * timer interrupt from previous kernel's context and is delivered in
1066 * new kernel the moment interrupts are enabled.
1068 * Interrupts are enabled early and LAPIC is setup much later, hence
1069 * its possible that when we get here evt->event_handler is NULL.
1070 * Check for event_handler being NULL and discard the interrupt as
1073 if (!evt->event_handler) {
1074 pr_warn("Spurious LAPIC timer interrupt on cpu %d\n",
1075 smp_processor_id());
1077 lapic_timer_shutdown(evt);
1082 * the NMI deadlock-detector uses this.
1084 inc_irq_stat(apic_timer_irqs);
1086 evt->event_handler(evt);
1090 * Local APIC timer interrupt. This is the most natural way for doing
1091 * local interrupts, but local timer interrupts can be emulated by
1092 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1094 * [ if a single-CPU system runs an SMP kernel then we call the local
1095 * interrupt as well. Thus we cannot inline the local irq ... ]
1097 DEFINE_IDTENTRY_SYSVEC(sysvec_apic_timer_interrupt)
1099 struct pt_regs *old_regs = set_irq_regs(regs);
1102 trace_local_timer_entry(LOCAL_TIMER_VECTOR);
1103 local_apic_timer_interrupt();
1104 trace_local_timer_exit(LOCAL_TIMER_VECTOR);
1106 set_irq_regs(old_regs);
1109 int setup_profiling_timer(unsigned int multiplier)
1115 * Local APIC start and shutdown
1119 * clear_local_APIC - shutdown the local APIC
1121 * This is called, when a CPU is disabled and before rebooting, so the state of
1122 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
1123 * leftovers during boot.
1125 void clear_local_APIC(void)
1130 /* APIC hasn't been mapped yet */
1131 if (!x2apic_mode && !apic_phys)
1134 maxlvt = lapic_get_maxlvt();
1136 * Masking an LVT entry can trigger a local APIC error
1137 * if the vector is zero. Mask LVTERR first to prevent this.
1140 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
1141 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
1144 * Careful: we have to set masks only first to deassert
1145 * any level-triggered sources.
1147 v = apic_read(APIC_LVTT);
1148 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
1149 v = apic_read(APIC_LVT0);
1150 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
1151 v = apic_read(APIC_LVT1);
1152 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
1154 v = apic_read(APIC_LVTPC);
1155 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
1158 /* lets not touch this if we didn't frob it */
1159 #ifdef CONFIG_X86_THERMAL_VECTOR
1161 v = apic_read(APIC_LVTTHMR);
1162 apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
1165 #ifdef CONFIG_X86_MCE_INTEL
1167 v = apic_read(APIC_LVTCMCI);
1168 if (!(v & APIC_LVT_MASKED))
1169 apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
1174 * Clean APIC state for other OSs:
1176 apic_write(APIC_LVTT, APIC_LVT_MASKED);
1177 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1178 apic_write(APIC_LVT1, APIC_LVT_MASKED);
1180 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
1182 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
1184 /* Integrated APIC (!82489DX) ? */
1185 if (lapic_is_integrated()) {
1187 /* Clear ESR due to Pentium errata 3AP and 11AP */
1188 apic_write(APIC_ESR, 0);
1189 apic_read(APIC_ESR);
1194 * apic_soft_disable - Clears and software disables the local APIC on hotplug
1196 * Contrary to disable_local_APIC() this does not touch the enable bit in
1197 * MSR_IA32_APICBASE. Clearing that bit on systems based on the 3 wire APIC
1198 * bus would require a hardware reset as the APIC would lose track of bus
1199 * arbitration. On systems with FSB delivery APICBASE could be disabled,
1200 * but it has to be guaranteed that no interrupt is sent to the APIC while
1201 * in that state and it's not clear from the SDM whether it still responds
1202 * to INIT/SIPI messages. Stay on the safe side and use software disable.
1204 void apic_soft_disable(void)
1210 /* Soft disable APIC (implies clearing of registers for 82489DX!). */
1211 value = apic_read(APIC_SPIV);
1212 value &= ~APIC_SPIV_APIC_ENABLED;
1213 apic_write(APIC_SPIV, value);
1217 * disable_local_APIC - clear and disable the local APIC
1219 void disable_local_APIC(void)
1221 /* APIC hasn't been mapped yet */
1222 if (!x2apic_mode && !apic_phys)
1225 apic_soft_disable();
1227 #ifdef CONFIG_X86_32
1229 * When LAPIC was disabled by the BIOS and enabled by the kernel,
1230 * restore the disabled state.
1232 if (enabled_via_apicbase) {
1235 rdmsr(MSR_IA32_APICBASE, l, h);
1236 l &= ~MSR_IA32_APICBASE_ENABLE;
1237 wrmsr(MSR_IA32_APICBASE, l, h);
1243 * If Linux enabled the LAPIC against the BIOS default disable it down before
1244 * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and
1245 * not power-off. Additionally clear all LVT entries before disable_local_APIC
1246 * for the case where Linux didn't enable the LAPIC.
1248 void lapic_shutdown(void)
1250 unsigned long flags;
1252 if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config())
1255 local_irq_save(flags);
1257 #ifdef CONFIG_X86_32
1258 if (!enabled_via_apicbase)
1262 disable_local_APIC();
1265 local_irq_restore(flags);
1269 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
1271 void __init sync_Arb_IDs(void)
1274 * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1277 if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1283 apic_wait_icr_idle();
1285 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1286 apic_write(APIC_ICR, APIC_DEST_ALLINC |
1287 APIC_INT_LEVELTRIG | APIC_DM_INIT);
1290 enum apic_intr_mode_id apic_intr_mode __ro_after_init;
1292 static int __init __apic_intr_mode_select(void)
1294 /* Check kernel option */
1296 pr_info("APIC disabled via kernel command line\n");
1301 #ifdef CONFIG_X86_64
1302 /* On 64-bit, the APIC must be integrated, Check local APIC only */
1303 if (!boot_cpu_has(X86_FEATURE_APIC)) {
1305 pr_info("APIC disabled by BIOS\n");
1309 /* On 32-bit, the APIC may be integrated APIC or 82489DX */
1311 /* Neither 82489DX nor integrated APIC ? */
1312 if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
1317 /* If the BIOS pretends there is an integrated APIC ? */
1318 if (!boot_cpu_has(X86_FEATURE_APIC) &&
1319 APIC_INTEGRATED(boot_cpu_apic_version)) {
1321 pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
1322 boot_cpu_physical_apicid);
1327 /* Check MP table or ACPI MADT configuration */
1328 if (!smp_found_config) {
1329 disable_ioapic_support();
1331 pr_info("APIC: ACPI MADT or MP tables are not detected\n");
1332 return APIC_VIRTUAL_WIRE_NO_CONFIG;
1334 return APIC_VIRTUAL_WIRE;
1338 /* If SMP should be disabled, then really disable it! */
1339 if (!setup_max_cpus) {
1340 pr_info("APIC: SMP mode deactivated\n");
1341 return APIC_SYMMETRIC_IO_NO_ROUTING;
1344 if (read_apic_id() != boot_cpu_physical_apicid) {
1345 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1346 read_apic_id(), boot_cpu_physical_apicid);
1347 /* Or can we switch back to PIC here? */
1351 return APIC_SYMMETRIC_IO;
1354 /* Select the interrupt delivery mode for the BSP */
1355 void __init apic_intr_mode_select(void)
1357 apic_intr_mode = __apic_intr_mode_select();
1361 * An initial setup of the virtual wire mode.
1363 void __init init_bsp_APIC(void)
1368 * Don't do the setup now if we have a SMP BIOS as the
1369 * through-I/O-APIC virtual wire mode might be active.
1371 if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
1375 * Do not trust the local APIC being empty at bootup.
1382 value = apic_read(APIC_SPIV);
1383 value &= ~APIC_VECTOR_MASK;
1384 value |= APIC_SPIV_APIC_ENABLED;
1386 #ifdef CONFIG_X86_32
1387 /* This bit is reserved on P4/Xeon and should be cleared */
1388 if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1389 (boot_cpu_data.x86 == 15))
1390 value &= ~APIC_SPIV_FOCUS_DISABLED;
1393 value |= APIC_SPIV_FOCUS_DISABLED;
1394 value |= SPURIOUS_APIC_VECTOR;
1395 apic_write(APIC_SPIV, value);
1398 * Set up the virtual wire mode.
1400 apic_write(APIC_LVT0, APIC_DM_EXTINT);
1401 value = APIC_DM_NMI;
1402 if (!lapic_is_integrated()) /* 82489DX */
1403 value |= APIC_LVT_LEVEL_TRIGGER;
1404 if (apic_extnmi == APIC_EXTNMI_NONE)
1405 value |= APIC_LVT_MASKED;
1406 apic_write(APIC_LVT1, value);
1409 static void __init apic_bsp_setup(bool upmode);
1411 /* Init the interrupt delivery mode for the BSP */
1412 void __init apic_intr_mode_init(void)
1414 bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
1416 switch (apic_intr_mode) {
1418 pr_info("APIC: Keep in PIC mode(8259)\n");
1420 case APIC_VIRTUAL_WIRE:
1421 pr_info("APIC: Switch to virtual wire mode setup\n");
1422 default_setup_apic_routing();
1424 case APIC_VIRTUAL_WIRE_NO_CONFIG:
1425 pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
1427 default_setup_apic_routing();
1429 case APIC_SYMMETRIC_IO:
1430 pr_info("APIC: Switch to symmetric I/O mode setup\n");
1431 default_setup_apic_routing();
1433 case APIC_SYMMETRIC_IO_NO_ROUTING:
1434 pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
1438 if (x86_platform.apic_post_init)
1439 x86_platform.apic_post_init();
1441 apic_bsp_setup(upmode);
1444 static void lapic_setup_esr(void)
1446 unsigned int oldvalue, value, maxlvt;
1448 if (!lapic_is_integrated()) {
1449 pr_info("No ESR for 82489DX.\n");
1453 if (apic->disable_esr) {
1455 * Something untraceable is creating bad interrupts on
1456 * secondary quads ... for the moment, just leave the
1457 * ESR disabled - we can't do anything useful with the
1458 * errors anyway - mbligh
1460 pr_info("Leaving ESR disabled.\n");
1464 maxlvt = lapic_get_maxlvt();
1465 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
1466 apic_write(APIC_ESR, 0);
1467 oldvalue = apic_read(APIC_ESR);
1469 /* enables sending errors */
1470 value = ERROR_APIC_VECTOR;
1471 apic_write(APIC_LVTERR, value);
1474 * spec says clear errors after enabling vector.
1477 apic_write(APIC_ESR, 0);
1478 value = apic_read(APIC_ESR);
1479 if (value != oldvalue)
1480 apic_printk(APIC_VERBOSE, "ESR value before enabling "
1481 "vector: 0x%08x after: 0x%08x\n",
1485 #define APIC_IR_REGS APIC_ISR_NR
1486 #define APIC_IR_BITS (APIC_IR_REGS * 32)
1487 #define APIC_IR_MAPSIZE (APIC_IR_BITS / BITS_PER_LONG)
1490 unsigned long map[APIC_IR_MAPSIZE];
1491 u32 regs[APIC_IR_REGS];
1494 static bool apic_check_and_ack(union apic_ir *irr, union apic_ir *isr)
1499 for (i = 0; i < APIC_IR_REGS; i++)
1500 irr->regs[i] = apic_read(APIC_IRR + i * 0x10);
1503 for (i = 0; i < APIC_IR_REGS; i++)
1504 isr->regs[i] = apic_read(APIC_ISR + i * 0x10);
1507 * If the ISR map is not empty. ACK the APIC and run another round
1508 * to verify whether a pending IRR has been unblocked and turned
1511 if (!bitmap_empty(isr->map, APIC_IR_BITS)) {
1513 * There can be multiple ISR bits set when a high priority
1514 * interrupt preempted a lower priority one. Issue an ACK
1517 for_each_set_bit(bit, isr->map, APIC_IR_BITS)
1522 return !bitmap_empty(irr->map, APIC_IR_BITS);
1526 * After a crash, we no longer service the interrupts and a pending
1527 * interrupt from previous kernel might still have ISR bit set.
1529 * Most probably by now the CPU has serviced that pending interrupt and it
1530 * might not have done the ack_APIC_irq() because it thought, interrupt
1531 * came from i8259 as ExtInt. LAPIC did not get EOI so it does not clear
1532 * the ISR bit and cpu thinks it has already serviced the interrupt. Hence
1533 * a vector might get locked. It was noticed for timer irq (vector
1534 * 0x31). Issue an extra EOI to clear ISR.
1536 * If there are pending IRR bits they turn into ISR bits after a higher
1537 * priority ISR bit has been acked.
1539 static void apic_pending_intr_clear(void)
1541 union apic_ir irr, isr;
1544 /* 512 loops are way oversized and give the APIC a chance to obey. */
1545 for (i = 0; i < 512; i++) {
1546 if (!apic_check_and_ack(&irr, &isr))
1549 /* Dump the IRR/ISR content if that failed */
1550 pr_warn("APIC: Stale IRR: %256pb ISR: %256pb\n", irr.map, isr.map);
1554 * setup_local_APIC - setup the local APIC
1556 * Used to setup local APIC while initializing BSP or bringing up APs.
1557 * Always called with preemption disabled.
1559 static void setup_local_APIC(void)
1561 int cpu = smp_processor_id();
1565 disable_ioapic_support();
1570 * If this comes from kexec/kcrash the APIC might be enabled in
1571 * SPIV. Soft disable it before doing further initialization.
1573 value = apic_read(APIC_SPIV);
1574 value &= ~APIC_SPIV_APIC_ENABLED;
1575 apic_write(APIC_SPIV, value);
1577 #ifdef CONFIG_X86_32
1578 /* Pound the ESR really hard over the head with a big hammer - mbligh */
1579 if (lapic_is_integrated() && apic->disable_esr) {
1580 apic_write(APIC_ESR, 0);
1581 apic_write(APIC_ESR, 0);
1582 apic_write(APIC_ESR, 0);
1583 apic_write(APIC_ESR, 0);
1587 * Double-check whether this APIC is really registered.
1588 * This is meaningless in clustered apic mode, so we skip it.
1590 BUG_ON(!apic->apic_id_registered());
1593 * Intel recommends to set DFR, LDR and TPR before enabling
1594 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
1595 * document number 292116). So here it goes...
1597 apic->init_apic_ldr();
1599 #ifdef CONFIG_X86_32
1600 if (apic->dest_mode_logical) {
1601 int logical_apicid, ldr_apicid;
1604 * APIC LDR is initialized. If logical_apicid mapping was
1605 * initialized during get_smp_config(), make sure it matches
1608 logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1609 ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
1610 if (logical_apicid != BAD_APICID)
1611 WARN_ON(logical_apicid != ldr_apicid);
1612 /* Always use the value from LDR. */
1613 early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
1618 * Set Task Priority to 'accept all except vectors 0-31'. An APIC
1619 * vector in the 16-31 range could be delivered if TPR == 0, but we
1620 * would think it's an exception and terrible things will happen. We
1621 * never change this later on.
1623 value = apic_read(APIC_TASKPRI);
1624 value &= ~APIC_TPRI_MASK;
1626 apic_write(APIC_TASKPRI, value);
1628 /* Clear eventually stale ISR/IRR bits */
1629 apic_pending_intr_clear();
1632 * Now that we are all set up, enable the APIC
1634 value = apic_read(APIC_SPIV);
1635 value &= ~APIC_VECTOR_MASK;
1639 value |= APIC_SPIV_APIC_ENABLED;
1641 #ifdef CONFIG_X86_32
1643 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
1644 * certain networking cards. If high frequency interrupts are
1645 * happening on a particular IOAPIC pin, plus the IOAPIC routing
1646 * entry is masked/unmasked at a high rate as well then sooner or
1647 * later IOAPIC line gets 'stuck', no more interrupts are received
1648 * from the device. If focus CPU is disabled then the hang goes
1651 * [ This bug can be reproduced easily with a level-triggered
1652 * PCI Ne2000 networking cards and PII/PIII processors, dual
1656 * Actually disabling the focus CPU check just makes the hang less
1657 * frequent as it makes the interrupt distribution model be more
1658 * like LRU than MRU (the short-term load is more even across CPUs).
1662 * - enable focus processor (bit==0)
1663 * - 64bit mode always use processor focus
1664 * so no need to set it
1666 value &= ~APIC_SPIV_FOCUS_DISABLED;
1670 * Set spurious IRQ vector
1672 value |= SPURIOUS_APIC_VECTOR;
1673 apic_write(APIC_SPIV, value);
1675 perf_events_lapic_init();
1678 * Set up LVT0, LVT1:
1680 * set up through-local-APIC on the boot CPU's LINT0. This is not
1681 * strictly necessary in pure symmetric-IO mode, but sometimes
1682 * we delegate interrupts to the 8259A.
1685 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
1687 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1688 if (!cpu && (pic_mode || !value || skip_ioapic_setup)) {
1689 value = APIC_DM_EXTINT;
1690 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1692 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1693 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1695 apic_write(APIC_LVT0, value);
1698 * Only the BSP sees the LINT1 NMI signal by default. This can be
1699 * modified by apic_extnmi= boot option.
1701 if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) ||
1702 apic_extnmi == APIC_EXTNMI_ALL)
1703 value = APIC_DM_NMI;
1705 value = APIC_DM_NMI | APIC_LVT_MASKED;
1708 if (!lapic_is_integrated())
1709 value |= APIC_LVT_LEVEL_TRIGGER;
1710 apic_write(APIC_LVT1, value);
1712 #ifdef CONFIG_X86_MCE_INTEL
1713 /* Recheck CMCI information after local APIC is up on CPU #0 */
1719 static void end_local_APIC_setup(void)
1723 #ifdef CONFIG_X86_32
1726 /* Disable the local apic timer */
1727 value = apic_read(APIC_LVTT);
1728 value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1729 apic_write(APIC_LVTT, value);
1737 * APIC setup function for application processors. Called from smpboot.c
1739 void apic_ap_setup(void)
1742 end_local_APIC_setup();
1745 #ifdef CONFIG_X86_X2APIC
1747 EXPORT_SYMBOL_GPL(x2apic_mode);
1754 static int x2apic_state;
1756 static void __x2apic_disable(void)
1760 if (!boot_cpu_has(X86_FEATURE_APIC))
1763 rdmsrl(MSR_IA32_APICBASE, msr);
1764 if (!(msr & X2APIC_ENABLE))
1766 /* Disable xapic and x2apic first and then reenable xapic mode */
1767 wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE));
1768 wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE);
1769 printk_once(KERN_INFO "x2apic disabled\n");
1772 static void __x2apic_enable(void)
1776 rdmsrl(MSR_IA32_APICBASE, msr);
1777 if (msr & X2APIC_ENABLE)
1779 wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
1780 printk_once(KERN_INFO "x2apic enabled\n");
1783 static int __init setup_nox2apic(char *str)
1785 if (x2apic_enabled()) {
1786 int apicid = native_apic_msr_read(APIC_ID);
1788 if (apicid >= 255) {
1789 pr_warn("Apicid: %08x, cannot enforce nox2apic\n",
1793 pr_warn("x2apic already enabled.\n");
1796 setup_clear_cpu_cap(X86_FEATURE_X2APIC);
1797 x2apic_state = X2APIC_DISABLED;
1801 early_param("nox2apic", setup_nox2apic);
1803 /* Called from cpu_init() to enable x2apic on (secondary) cpus */
1804 void x2apic_setup(void)
1807 * If x2apic is not in ON state, disable it if already enabled
1810 if (x2apic_state != X2APIC_ON) {
1817 static __init void x2apic_disable(void)
1819 u32 x2apic_id, state = x2apic_state;
1822 x2apic_state = X2APIC_DISABLED;
1824 if (state != X2APIC_ON)
1827 x2apic_id = read_apic_id();
1828 if (x2apic_id >= 255)
1829 panic("Cannot disable x2apic, id: %08x\n", x2apic_id);
1832 register_lapic_address(mp_lapic_addr);
1835 static __init void x2apic_enable(void)
1837 if (x2apic_state != X2APIC_OFF)
1841 x2apic_state = X2APIC_ON;
1845 static __init void try_to_enable_x2apic(int remap_mode)
1847 if (x2apic_state == X2APIC_DISABLED)
1850 if (remap_mode != IRQ_REMAP_X2APIC_MODE) {
1851 u32 apic_limit = 255;
1854 * Using X2APIC without IR is not architecturally supported
1855 * on bare metal but may be supported in guests.
1857 if (!x86_init.hyper.x2apic_available()) {
1858 pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
1864 * If the hypervisor supports extended destination ID in
1865 * MSI, that increases the maximum APIC ID that can be
1866 * used for non-remapped IRQ domains.
1868 if (x86_init.hyper.msi_ext_dest_id()) {
1869 virt_ext_dest_id = 1;
1874 * Without IR, all CPUs can be addressed by IOAPIC/MSI only
1875 * in physical mode, and CPUs with an APIC ID that cannot
1876 * be addressed must not be brought online.
1878 x2apic_set_max_apicid(apic_limit);
1884 void __init check_x2apic(void)
1886 if (x2apic_enabled()) {
1887 pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n");
1889 x2apic_state = X2APIC_ON;
1890 } else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
1891 x2apic_state = X2APIC_DISABLED;
1894 #else /* CONFIG_X86_X2APIC */
1895 static int __init validate_x2apic(void)
1897 if (!apic_is_x2apic_enabled())
1900 * Checkme: Can we simply turn off x2apic here instead of panic?
1902 panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
1904 early_initcall(validate_x2apic);
1906 static inline void try_to_enable_x2apic(int remap_mode) { }
1907 static inline void __x2apic_enable(void) { }
1908 #endif /* !CONFIG_X86_X2APIC */
1910 void __init enable_IR_x2apic(void)
1912 unsigned long flags;
1915 if (skip_ioapic_setup) {
1916 pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
1920 ir_stat = irq_remapping_prepare();
1921 if (ir_stat < 0 && !x2apic_supported())
1924 ret = save_ioapic_entries();
1926 pr_info("Saving IO-APIC state failed: %d\n", ret);
1930 local_irq_save(flags);
1931 legacy_pic->mask_all();
1932 mask_ioapic_entries();
1934 /* If irq_remapping_prepare() succeeded, try to enable it */
1936 ir_stat = irq_remapping_enable();
1937 /* ir_stat contains the remap mode or an error code */
1938 try_to_enable_x2apic(ir_stat);
1941 restore_ioapic_entries();
1942 legacy_pic->restore_mask();
1943 local_irq_restore(flags);
1946 #ifdef CONFIG_X86_64
1948 * Detect and enable local APICs on non-SMP boards.
1949 * Original code written by Keir Fraser.
1950 * On AMD64 we trust the BIOS - if it says no APIC it is likely
1951 * not correctly set up (usually the APIC timer won't work etc.)
1953 static int __init detect_init_APIC(void)
1955 if (!boot_cpu_has(X86_FEATURE_APIC)) {
1956 pr_info("No local APIC present\n");
1960 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1965 static int __init apic_verify(void)
1970 * The APIC feature bit should now be enabled
1973 features = cpuid_edx(1);
1974 if (!(features & (1 << X86_FEATURE_APIC))) {
1975 pr_warn("Could not enable APIC!\n");
1978 set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1979 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1981 /* The BIOS may have set up the APIC at some other address */
1982 if (boot_cpu_data.x86 >= 6) {
1983 rdmsr(MSR_IA32_APICBASE, l, h);
1984 if (l & MSR_IA32_APICBASE_ENABLE)
1985 mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1988 pr_info("Found and enabled local APIC!\n");
1992 int __init apic_force_enable(unsigned long addr)
2000 * Some BIOSes disable the local APIC in the APIC_BASE
2001 * MSR. This can only be done in software for Intel P6 or later
2002 * and AMD K7 (Model > 1) or later.
2004 if (boot_cpu_data.x86 >= 6) {
2005 rdmsr(MSR_IA32_APICBASE, l, h);
2006 if (!(l & MSR_IA32_APICBASE_ENABLE)) {
2007 pr_info("Local APIC disabled by BIOS -- reenabling.\n");
2008 l &= ~MSR_IA32_APICBASE_BASE;
2009 l |= MSR_IA32_APICBASE_ENABLE | addr;
2010 wrmsr(MSR_IA32_APICBASE, l, h);
2011 enabled_via_apicbase = 1;
2014 return apic_verify();
2018 * Detect and initialize APIC
2020 static int __init detect_init_APIC(void)
2022 /* Disabled by kernel option? */
2026 switch (boot_cpu_data.x86_vendor) {
2027 case X86_VENDOR_AMD:
2028 if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
2029 (boot_cpu_data.x86 >= 15))
2032 case X86_VENDOR_HYGON:
2034 case X86_VENDOR_INTEL:
2035 if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
2036 (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
2043 if (!boot_cpu_has(X86_FEATURE_APIC)) {
2045 * Over-ride BIOS and try to enable the local APIC only if
2046 * "lapic" specified.
2048 if (!force_enable_local_apic) {
2049 pr_info("Local APIC disabled by BIOS -- "
2050 "you can enable it with \"lapic\"\n");
2053 if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
2065 pr_info("No local APIC present or hardware disabled\n");
2071 * init_apic_mappings - initialize APIC mappings
2073 void __init init_apic_mappings(void)
2075 unsigned int new_apicid;
2077 if (apic_validate_deadline_timer())
2078 pr_info("TSC deadline timer available\n");
2081 boot_cpu_physical_apicid = read_apic_id();
2085 /* If no local APIC can be found return early */
2086 if (!smp_found_config && detect_init_APIC()) {
2087 /* lets NOP'ify apic operations */
2088 pr_info("APIC: disable apic facility\n");
2091 apic_phys = mp_lapic_addr;
2094 * If the system has ACPI MADT tables or MP info, the LAPIC
2095 * address is already registered.
2097 if (!acpi_lapic && !smp_found_config)
2098 register_lapic_address(apic_phys);
2102 * Fetch the APIC ID of the BSP in case we have a
2103 * default configuration (or the MP table is broken).
2105 new_apicid = read_apic_id();
2106 if (boot_cpu_physical_apicid != new_apicid) {
2107 boot_cpu_physical_apicid = new_apicid;
2109 * yeah -- we lie about apic_version
2110 * in case if apic was disabled via boot option
2111 * but it's not a problem for SMP compiled kernel
2112 * since apic_intr_mode_select is prepared for such
2113 * a case and disable smp mode
2115 boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2119 void __init register_lapic_address(unsigned long address)
2121 mp_lapic_addr = address;
2124 set_fixmap_nocache(FIX_APIC_BASE, address);
2125 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
2126 APIC_BASE, address);
2128 if (boot_cpu_physical_apicid == -1U) {
2129 boot_cpu_physical_apicid = read_apic_id();
2130 boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
2135 * Local APIC interrupts
2139 * Common handling code for spurious_interrupt and spurious_vector entry
2140 * points below. No point in allowing the compiler to inline it twice.
2142 static noinline void handle_spurious_interrupt(u8 vector)
2146 trace_spurious_apic_entry(vector);
2148 inc_irq_stat(irq_spurious_count);
2151 * If this is a spurious interrupt then do not acknowledge
2153 if (vector == SPURIOUS_APIC_VECTOR) {
2155 pr_info("Spurious APIC interrupt (vector 0xFF) on CPU#%d, should never happen.\n",
2156 smp_processor_id());
2161 * If it is a vectored one, verify it's set in the ISR. If set,
2164 v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
2165 if (v & (1 << (vector & 0x1f))) {
2166 pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Acked\n",
2167 vector, smp_processor_id());
2170 pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Not pending!\n",
2171 vector, smp_processor_id());
2174 trace_spurious_apic_exit(vector);
2178 * spurious_interrupt - Catch all for interrupts raised on unused vectors
2179 * @regs: Pointer to pt_regs on stack
2180 * @vector: The vector number
2182 * This is invoked from ASM entry code to catch all interrupts which
2183 * trigger on an entry which is routed to the common_spurious idtentry
2186 DEFINE_IDTENTRY_IRQ(spurious_interrupt)
2188 handle_spurious_interrupt(vector);
2191 DEFINE_IDTENTRY_SYSVEC(sysvec_spurious_apic_interrupt)
2193 handle_spurious_interrupt(SPURIOUS_APIC_VECTOR);
2197 * This interrupt should never happen with our APIC/SMP architecture
2199 DEFINE_IDTENTRY_SYSVEC(sysvec_error_interrupt)
2201 static const char * const error_interrupt_reason[] = {
2202 "Send CS error", /* APIC Error Bit 0 */
2203 "Receive CS error", /* APIC Error Bit 1 */
2204 "Send accept error", /* APIC Error Bit 2 */
2205 "Receive accept error", /* APIC Error Bit 3 */
2206 "Redirectable IPI", /* APIC Error Bit 4 */
2207 "Send illegal vector", /* APIC Error Bit 5 */
2208 "Received illegal vector", /* APIC Error Bit 6 */
2209 "Illegal register address", /* APIC Error Bit 7 */
2213 trace_error_apic_entry(ERROR_APIC_VECTOR);
2215 /* First tickle the hardware, only then report what went on. -- REW */
2216 if (lapic_get_maxlvt() > 3) /* Due to the Pentium erratum 3AP. */
2217 apic_write(APIC_ESR, 0);
2218 v = apic_read(APIC_ESR);
2220 atomic_inc(&irq_err_count);
2222 apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x",
2223 smp_processor_id(), v);
2228 apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
2233 apic_printk(APIC_DEBUG, KERN_CONT "\n");
2235 trace_error_apic_exit(ERROR_APIC_VECTOR);
2239 * connect_bsp_APIC - attach the APIC to the interrupt system
2241 static void __init connect_bsp_APIC(void)
2243 #ifdef CONFIG_X86_32
2246 * Do not trust the local APIC being empty at bootup.
2250 * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
2251 * local APIC to INT and NMI lines.
2253 apic_printk(APIC_VERBOSE, "leaving PIC mode, "
2254 "enabling APIC mode.\n");
2261 * disconnect_bsp_APIC - detach the APIC from the interrupt system
2262 * @virt_wire_setup: indicates, whether virtual wire mode is selected
2264 * Virtual wire mode is necessary to deliver legacy interrupts even when the
2267 void disconnect_bsp_APIC(int virt_wire_setup)
2271 #ifdef CONFIG_X86_32
2274 * Put the board back into PIC mode (has an effect only on
2275 * certain older boards). Note that APIC interrupts, including
2276 * IPIs, won't work beyond this point! The only exception are
2279 apic_printk(APIC_VERBOSE, "disabling APIC mode, "
2280 "entering PIC mode.\n");
2286 /* Go back to Virtual Wire compatibility mode */
2288 /* For the spurious interrupt use vector F, and enable it */
2289 value = apic_read(APIC_SPIV);
2290 value &= ~APIC_VECTOR_MASK;
2291 value |= APIC_SPIV_APIC_ENABLED;
2293 apic_write(APIC_SPIV, value);
2295 if (!virt_wire_setup) {
2297 * For LVT0 make it edge triggered, active high,
2298 * external and enabled
2300 value = apic_read(APIC_LVT0);
2301 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2302 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2303 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2304 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2305 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
2306 apic_write(APIC_LVT0, value);
2309 apic_write(APIC_LVT0, APIC_LVT_MASKED);
2313 * For LVT1 make it edge triggered, active high,
2316 value = apic_read(APIC_LVT1);
2317 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
2318 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
2319 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
2320 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
2321 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
2322 apic_write(APIC_LVT1, value);
2326 * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
2327 * contiguously, it equals to current allocated max logical CPU ID plus 1.
2328 * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
2329 * so the maximum of nr_logical_cpuids is nr_cpu_ids.
2331 * NOTE: Reserve 0 for BSP.
2333 static int nr_logical_cpuids = 1;
2336 * Used to store mapping between logical CPU IDs and APIC IDs.
2338 static int cpuid_to_apicid[] = {
2339 [0 ... NR_CPUS - 1] = -1,
2342 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
2344 return phys_id == cpuid_to_apicid[cpu];
2349 * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
2350 * @apicid: APIC ID to check
2352 bool apic_id_is_primary_thread(unsigned int apicid)
2356 if (smp_num_siblings == 1)
2358 /* Isolate the SMT bit(s) in the APICID and check for 0 */
2359 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
2360 return !(apicid & mask);
2365 * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
2366 * and cpuid_to_apicid[] synchronized.
2368 static int allocate_logical_cpuid(int apicid)
2373 * cpuid <-> apicid mapping is persistent, so when a cpu is up,
2374 * check if the kernel has allocated a cpuid for it.
2376 for (i = 0; i < nr_logical_cpuids; i++) {
2377 if (cpuid_to_apicid[i] == apicid)
2381 /* Allocate a new cpuid. */
2382 if (nr_logical_cpuids >= nr_cpu_ids) {
2383 WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
2384 "Processor %d/0x%x and the rest are ignored.\n",
2385 nr_cpu_ids, nr_logical_cpuids, apicid);
2389 cpuid_to_apicid[nr_logical_cpuids] = apicid;
2390 return nr_logical_cpuids++;
2393 int generic_processor_info(int apicid, int version)
2395 int cpu, max = nr_cpu_ids;
2396 bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
2397 phys_cpu_present_map);
2400 * boot_cpu_physical_apicid is designed to have the apicid
2401 * returned by read_apic_id(), i.e, the apicid of the
2402 * currently booting-up processor. However, on some platforms,
2403 * it is temporarily modified by the apicid reported as BSP
2404 * through MP table. Concretely:
2406 * - arch/x86/kernel/mpparse.c: MP_processor_info()
2407 * - arch/x86/mm/amdtopology.c: amd_numa_init()
2409 * This function is executed with the modified
2410 * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel
2411 * parameter doesn't work to disable APs on kdump 2nd kernel.
2413 * Since fixing handling of boot_cpu_physical_apicid requires
2414 * another discussion and tests on each platform, we leave it
2415 * for now and here we use read_apic_id() directly in this
2416 * function, generic_processor_info().
2418 if (disabled_cpu_apicid != BAD_APICID &&
2419 disabled_cpu_apicid != read_apic_id() &&
2420 disabled_cpu_apicid == apicid) {
2421 int thiscpu = num_processors + disabled_cpus;
2423 pr_warn("APIC: Disabling requested cpu."
2424 " Processor %d/0x%x ignored.\n", thiscpu, apicid);
2431 * If boot cpu has not been detected yet, then only allow upto
2432 * nr_cpu_ids - 1 processors and keep one slot free for boot cpu
2434 if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
2435 apicid != boot_cpu_physical_apicid) {
2436 int thiscpu = max + disabled_cpus - 1;
2438 pr_warn("APIC: NR_CPUS/possible_cpus limit of %i almost"
2439 " reached. Keeping one slot for boot cpu."
2440 " Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2446 if (num_processors >= nr_cpu_ids) {
2447 int thiscpu = max + disabled_cpus;
2449 pr_warn("APIC: NR_CPUS/possible_cpus limit of %i reached. "
2450 "Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
2456 if (apicid == boot_cpu_physical_apicid) {
2458 * x86_bios_cpu_apicid is required to have processors listed
2459 * in same order as logical cpu numbers. Hence the first
2460 * entry is BSP, and so on.
2461 * boot_cpu_init() already hold bit 0 in cpu_present_mask
2466 /* Logical cpuid 0 is reserved for BSP. */
2467 cpuid_to_apicid[0] = apicid;
2469 cpu = allocate_logical_cpuid(apicid);
2479 if (version == 0x0) {
2480 pr_warn("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2485 if (version != boot_cpu_apic_version) {
2486 pr_warn("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2487 boot_cpu_apic_version, cpu, version);
2490 if (apicid > max_physical_apicid)
2491 max_physical_apicid = apicid;
2493 #if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2494 early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2495 early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2497 #ifdef CONFIG_X86_32
2498 early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2499 apic->x86_32_early_logical_apicid(cpu);
2501 set_cpu_possible(cpu, true);
2502 physid_set(apicid, phys_cpu_present_map);
2503 set_cpu_present(cpu, true);
2509 int hard_smp_processor_id(void)
2511 return read_apic_id();
2514 void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
2517 memset(msg, 0, sizeof(*msg));
2519 msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
2520 msg->arch_addr_lo.dest_mode_logical = apic->dest_mode_logical;
2521 msg->arch_addr_lo.destid_0_7 = cfg->dest_apicid & 0xFF;
2523 msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_FIXED;
2524 msg->arch_data.vector = cfg->vector;
2526 msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
2528 * Only the IOMMU itself can use the trick of putting destination
2529 * APIC ID into the high bits of the address. Anything else would
2530 * just be writing to memory if it tried that, and needs IR to
2531 * address APICs which can't be addressed in the normal 32-bit
2532 * address range at 0xFFExxxxx. That is typically just 8 bits, but
2533 * some hypervisors allow the extended destination ID field in bits
2534 * 5-11 to be used, giving support for 15 bits of APIC IDs in total.
2537 msg->arch_addr_hi.destid_8_31 = cfg->dest_apicid >> 8;
2538 else if (virt_ext_dest_id && cfg->dest_apicid < 0x8000)
2539 msg->arch_addr_lo.virt_destid_8_14 = cfg->dest_apicid >> 8;
2541 WARN_ON_ONCE(cfg->dest_apicid > 0xFF);
2544 u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid)
2546 u32 dest = msg->arch_addr_lo.destid_0_7;
2549 dest |= msg->arch_addr_hi.destid_8_31 << 8;
2552 EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
2555 * Override the generic EOI implementation with an optimized version.
2556 * Only called during early boot when only one CPU is active and with
2557 * interrupts disabled, so we know this does not race with actual APIC driver
2560 void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v))
2564 for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
2565 /* Should happen once for each apic */
2566 WARN_ON((*drv)->eoi_write == eoi_write);
2567 (*drv)->native_eoi_write = (*drv)->eoi_write;
2568 (*drv)->eoi_write = eoi_write;
2572 static void __init apic_bsp_up_setup(void)
2574 #ifdef CONFIG_X86_64
2575 apic_write(APIC_ID, apic->set_apic_id(boot_cpu_physical_apicid));
2578 * Hack: In case of kdump, after a crash, kernel might be booting
2579 * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
2580 * might be zero if read from MP tables. Get it from LAPIC.
2582 # ifdef CONFIG_CRASH_DUMP
2583 boot_cpu_physical_apicid = read_apic_id();
2586 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
2590 * apic_bsp_setup - Setup function for local apic and io-apic
2591 * @upmode: Force UP mode (for APIC_init_uniprocessor)
2593 static void __init apic_bsp_setup(bool upmode)
2597 apic_bsp_up_setup();
2601 end_local_APIC_setup();
2602 irq_remap_enable_fault_handling();
2604 lapic_update_legacy_vectors();
2607 #ifdef CONFIG_UP_LATE_INIT
2608 void __init up_late_init(void)
2610 if (apic_intr_mode == APIC_PIC)
2613 /* Setup local timer */
2614 x86_init.timers.setup_percpu_clockev();
2625 * 'active' is true if the local APIC was enabled by us and
2626 * not the BIOS; this signifies that we are also responsible
2627 * for disabling it before entering apm/acpi suspend
2630 /* r/w apic fields */
2631 unsigned int apic_id;
2632 unsigned int apic_taskpri;
2633 unsigned int apic_ldr;
2634 unsigned int apic_dfr;
2635 unsigned int apic_spiv;
2636 unsigned int apic_lvtt;
2637 unsigned int apic_lvtpc;
2638 unsigned int apic_lvt0;
2639 unsigned int apic_lvt1;
2640 unsigned int apic_lvterr;
2641 unsigned int apic_tmict;
2642 unsigned int apic_tdcr;
2643 unsigned int apic_thmr;
2644 unsigned int apic_cmci;
2647 static int lapic_suspend(void)
2649 unsigned long flags;
2652 if (!apic_pm_state.active)
2655 maxlvt = lapic_get_maxlvt();
2657 apic_pm_state.apic_id = apic_read(APIC_ID);
2658 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2659 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2660 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2661 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2662 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2664 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2665 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2666 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2667 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2668 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2669 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2670 #ifdef CONFIG_X86_THERMAL_VECTOR
2672 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2674 #ifdef CONFIG_X86_MCE_INTEL
2676 apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI);
2679 local_irq_save(flags);
2682 * Mask IOAPIC before disabling the local APIC to prevent stale IRR
2683 * entries on some implementations.
2685 mask_ioapic_entries();
2687 disable_local_APIC();
2689 irq_remapping_disable();
2691 local_irq_restore(flags);
2695 static void lapic_resume(void)
2698 unsigned long flags;
2701 if (!apic_pm_state.active)
2704 local_irq_save(flags);
2707 * IO-APIC and PIC have their own resume routines.
2708 * We just mask them here to make sure the interrupt
2709 * subsystem is completely quiet while we enable x2apic
2710 * and interrupt-remapping.
2712 mask_ioapic_entries();
2713 legacy_pic->mask_all();
2719 * Make sure the APICBASE points to the right address
2721 * FIXME! This will be wrong if we ever support suspend on
2722 * SMP! We'll need to do this as part of the CPU restore!
2724 if (boot_cpu_data.x86 >= 6) {
2725 rdmsr(MSR_IA32_APICBASE, l, h);
2726 l &= ~MSR_IA32_APICBASE_BASE;
2727 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2728 wrmsr(MSR_IA32_APICBASE, l, h);
2732 maxlvt = lapic_get_maxlvt();
2733 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2734 apic_write(APIC_ID, apic_pm_state.apic_id);
2735 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2736 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2737 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2738 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2739 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2740 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2741 #ifdef CONFIG_X86_THERMAL_VECTOR
2743 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2745 #ifdef CONFIG_X86_MCE_INTEL
2747 apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci);
2750 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2751 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2752 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2753 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2754 apic_write(APIC_ESR, 0);
2755 apic_read(APIC_ESR);
2756 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2757 apic_write(APIC_ESR, 0);
2758 apic_read(APIC_ESR);
2760 irq_remapping_reenable(x2apic_mode);
2762 local_irq_restore(flags);
2766 * This device has no shutdown method - fully functioning local APICs
2767 * are needed on every CPU up until machine_halt/restart/poweroff.
2770 static struct syscore_ops lapic_syscore_ops = {
2771 .resume = lapic_resume,
2772 .suspend = lapic_suspend,
2775 static void apic_pm_activate(void)
2777 apic_pm_state.active = 1;
2780 static int __init init_lapic_sysfs(void)
2782 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2783 if (boot_cpu_has(X86_FEATURE_APIC))
2784 register_syscore_ops(&lapic_syscore_ops);
2789 /* local apic needs to resume before other devices access its registers. */
2790 core_initcall(init_lapic_sysfs);
2792 #else /* CONFIG_PM */
2794 static void apic_pm_activate(void) { }
2796 #endif /* CONFIG_PM */
2798 #ifdef CONFIG_X86_64
2800 static int multi_checked;
2803 static int set_multi(const struct dmi_system_id *d)
2807 pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2812 static const struct dmi_system_id multi_dmi_table[] = {
2814 .callback = set_multi,
2815 .ident = "IBM System Summit2",
2817 DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2818 DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2824 static void dmi_check_multi(void)
2829 dmi_check_system(multi_dmi_table);
2834 * apic_is_clustered_box() -- Check if we can expect good TSC
2836 * Thus far, the major user of this is IBM's Summit2 series:
2837 * Clustered boxes may have unsynced TSC problems if they are
2839 * Use DMI to check them
2841 int apic_is_clustered_box(void)
2849 * APIC command line parameters
2851 static int __init setup_disableapic(char *arg)
2854 setup_clear_cpu_cap(X86_FEATURE_APIC);
2857 early_param("disableapic", setup_disableapic);
2859 /* same as disableapic, for compatibility */
2860 static int __init setup_nolapic(char *arg)
2862 return setup_disableapic(arg);
2864 early_param("nolapic", setup_nolapic);
2866 static int __init parse_lapic_timer_c2_ok(char *arg)
2868 local_apic_timer_c2_ok = 1;
2871 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2873 static int __init parse_disable_apic_timer(char *arg)
2875 disable_apic_timer = 1;
2878 early_param("noapictimer", parse_disable_apic_timer);
2880 static int __init parse_nolapic_timer(char *arg)
2882 disable_apic_timer = 1;
2885 early_param("nolapic_timer", parse_nolapic_timer);
2887 static int __init apic_set_verbosity(char *arg)
2890 #ifdef CONFIG_X86_64
2891 skip_ioapic_setup = 0;
2897 if (strcmp("debug", arg) == 0)
2898 apic_verbosity = APIC_DEBUG;
2899 else if (strcmp("verbose", arg) == 0)
2900 apic_verbosity = APIC_VERBOSE;
2901 #ifdef CONFIG_X86_64
2903 pr_warn("APIC Verbosity level %s not recognised"
2904 " use apic=verbose or apic=debug\n", arg);
2911 early_param("apic", apic_set_verbosity);
2913 static int __init lapic_insert_resource(void)
2918 /* Put local APIC into the resource map. */
2919 lapic_resource.start = apic_phys;
2920 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2921 insert_resource(&iomem_resource, &lapic_resource);
2927 * need call insert after e820__reserve_resources()
2928 * that is using request_resource
2930 late_initcall(lapic_insert_resource);
2932 static int __init apic_set_disabled_cpu_apicid(char *arg)
2934 if (!arg || !get_option(&arg, &disabled_cpu_apicid))
2939 early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid);
2941 static int __init apic_set_extnmi(char *arg)
2946 if (!strncmp("all", arg, 3))
2947 apic_extnmi = APIC_EXTNMI_ALL;
2948 else if (!strncmp("none", arg, 4))
2949 apic_extnmi = APIC_EXTNMI_NONE;
2950 else if (!strncmp("bsp", arg, 3))
2951 apic_extnmi = APIC_EXTNMI_BSP;
2953 pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg);
2959 early_param("apic_extnmi", apic_set_extnmi);