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>
31 #include <asm/atomic.h>
34 #include <asm/mpspec.h>
36 #include <asm/pgalloc.h>
39 #include <asm/proto.h>
40 #include <asm/timex.h>
44 #include <mach_apic.h>
46 static int disable_apic_timer __cpuinitdata;
47 static int apic_calibrate_pmtmr __initdata;
51 /* Local APIC timer works in C2 */
52 int local_apic_timer_c2_ok;
53 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
56 * Debug level, exported for io_apic.c
60 /* Have we found an MP table */
63 static struct resource lapic_resource = {
65 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
68 static unsigned int calibration_result;
70 static int lapic_next_event(unsigned long delta,
71 struct clock_event_device *evt);
72 static void lapic_timer_setup(enum clock_event_mode mode,
73 struct clock_event_device *evt);
74 static void lapic_timer_broadcast(cpumask_t mask);
75 static void apic_pm_activate(void);
77 static struct clock_event_device lapic_clockevent = {
79 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
80 | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
82 .set_mode = lapic_timer_setup,
83 .set_next_event = lapic_next_event,
84 .broadcast = lapic_timer_broadcast,
88 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
90 static unsigned long apic_phys;
92 unsigned long mp_lapic_addr;
94 unsigned int __cpuinitdata maxcpus = NR_CPUS;
96 * Get the LAPIC version
98 static inline int lapic_get_version(void)
100 return GET_APIC_VERSION(apic_read(APIC_LVR));
104 * Check, if the APIC is integrated or a seperate chip
106 static inline int lapic_is_integrated(void)
112 * Check, whether this is a modern or a first generation APIC
114 static int modern_apic(void)
116 /* AMD systems use old APIC versions, so check the CPU */
117 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
118 boot_cpu_data.x86 >= 0xf)
120 return lapic_get_version() >= 0x14;
123 void xapic_wait_icr_idle(void)
125 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
129 u32 safe_xapic_wait_icr_idle(void)
136 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
140 } while (timeout++ < 1000);
145 void xapic_icr_write(u32 low, u32 id)
147 apic_write(APIC_ICR2, id << 24);
148 apic_write(APIC_ICR, low);
151 u64 xapic_icr_read(void)
155 icr2 = apic_read(APIC_ICR2);
156 icr1 = apic_read(APIC_ICR);
158 return (icr1 | ((u64)icr2 << 32));
161 static struct apic_ops xapic_ops = {
162 .read = native_apic_mem_read,
163 .write = native_apic_mem_write,
164 .write_atomic = native_apic_mem_write_atomic,
165 .icr_read = xapic_icr_read,
166 .icr_write = xapic_icr_write,
167 .wait_icr_idle = xapic_wait_icr_idle,
168 .safe_wait_icr_idle = safe_xapic_wait_icr_idle,
171 struct apic_ops __read_mostly *apic_ops = &xapic_ops;
173 EXPORT_SYMBOL_GPL(apic_ops);
175 static void x2apic_wait_icr_idle(void)
177 /* no need to wait for icr idle in x2apic */
181 static u32 safe_x2apic_wait_icr_idle(void)
183 /* no need to wait for icr idle in x2apic */
187 void x2apic_icr_write(u32 low, u32 id)
189 wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
192 u64 x2apic_icr_read(void)
196 rdmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), val);
200 static struct apic_ops x2apic_ops = {
201 .read = native_apic_msr_read,
202 .write = native_apic_msr_write,
203 .write_atomic = native_apic_msr_write,
204 .icr_read = x2apic_icr_read,
205 .icr_write = x2apic_icr_write,
206 .wait_icr_idle = x2apic_wait_icr_idle,
207 .safe_wait_icr_idle = safe_x2apic_wait_icr_idle,
211 * enable_NMI_through_LVT0 - enable NMI through local vector table 0
213 void __cpuinit enable_NMI_through_LVT0(void)
217 /* unmask and set to NMI */
219 apic_write(APIC_LVT0, v);
223 * lapic_get_maxlvt - get the maximum number of local vector table entries
225 int lapic_get_maxlvt(void)
227 unsigned int v, maxlvt;
229 v = apic_read(APIC_LVR);
230 maxlvt = GET_APIC_MAXLVT(v);
235 * This function sets up the local APIC timer, with a timeout of
236 * 'clocks' APIC bus clock. During calibration we actually call
237 * this function twice on the boot CPU, once with a bogus timeout
238 * value, second time for real. The other (noncalibrating) CPUs
239 * call this function only once, with the real, calibrated value.
241 * We do reads before writes even if unnecessary, to get around the
242 * P5 APIC double write bug.
245 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
247 unsigned int lvtt_value, tmp_value;
249 lvtt_value = LOCAL_TIMER_VECTOR;
251 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
253 lvtt_value |= APIC_LVT_MASKED;
255 apic_write(APIC_LVTT, lvtt_value);
260 tmp_value = apic_read(APIC_TDCR);
261 apic_write(APIC_TDCR, (tmp_value
262 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
266 apic_write(APIC_TMICT, clocks);
270 * Setup extended LVT, AMD specific (K8, family 10h)
272 * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
273 * MCE interrupts are supported. Thus MCE offset must be set to 0.
276 #define APIC_EILVT_LVTOFF_MCE 0
277 #define APIC_EILVT_LVTOFF_IBS 1
279 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
281 unsigned long reg = (lvt_off << 4) + APIC_EILVT0;
282 unsigned int v = (mask << 16) | (msg_type << 8) | vector;
287 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
289 setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
290 return APIC_EILVT_LVTOFF_MCE;
293 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
295 setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
296 return APIC_EILVT_LVTOFF_IBS;
300 * Program the next event, relative to now
302 static int lapic_next_event(unsigned long delta,
303 struct clock_event_device *evt)
305 apic_write(APIC_TMICT, delta);
310 * Setup the lapic timer in periodic or oneshot mode
312 static void lapic_timer_setup(enum clock_event_mode mode,
313 struct clock_event_device *evt)
318 /* Lapic used as dummy for broadcast ? */
319 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
322 local_irq_save(flags);
325 case CLOCK_EVT_MODE_PERIODIC:
326 case CLOCK_EVT_MODE_ONESHOT:
327 __setup_APIC_LVTT(calibration_result,
328 mode != CLOCK_EVT_MODE_PERIODIC, 1);
330 case CLOCK_EVT_MODE_UNUSED:
331 case CLOCK_EVT_MODE_SHUTDOWN:
332 v = apic_read(APIC_LVTT);
333 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
334 apic_write(APIC_LVTT, v);
336 case CLOCK_EVT_MODE_RESUME:
337 /* Nothing to do here */
341 local_irq_restore(flags);
345 * Local APIC timer broadcast function
347 static void lapic_timer_broadcast(cpumask_t mask)
350 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
355 * Setup the local APIC timer for this CPU. Copy the initilized values
356 * of the boot CPU and register the clock event in the framework.
358 static void setup_APIC_timer(void)
360 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
362 memcpy(levt, &lapic_clockevent, sizeof(*levt));
363 levt->cpumask = cpumask_of_cpu(smp_processor_id());
365 clockevents_register_device(levt);
369 * In this function we calibrate APIC bus clocks to the external
370 * timer. Unfortunately we cannot use jiffies and the timer irq
371 * to calibrate, since some later bootup code depends on getting
372 * the first irq? Ugh.
374 * We want to do the calibration only once since we
375 * want to have local timer irqs syncron. CPUs connected
376 * by the same APIC bus have the very same bus frequency.
377 * And we want to have irqs off anyways, no accidental
381 #define TICK_COUNT 100000000
383 static void __init calibrate_APIC_clock(void)
385 unsigned apic, apic_start;
386 unsigned long tsc, tsc_start;
392 * Put whatever arbitrary (but long enough) timeout
393 * value into the APIC clock, we just want to get the
394 * counter running for calibration.
396 * No interrupt enable !
398 __setup_APIC_LVTT(250000000, 0, 0);
400 apic_start = apic_read(APIC_TMCCT);
401 #ifdef CONFIG_X86_PM_TIMER
402 if (apic_calibrate_pmtmr && pmtmr_ioport) {
403 pmtimer_wait(5000); /* 5ms wait */
404 apic = apic_read(APIC_TMCCT);
405 result = (apic_start - apic) * 1000L / 5;
412 apic = apic_read(APIC_TMCCT);
414 } while ((tsc - tsc_start) < TICK_COUNT &&
415 (apic_start - apic) < TICK_COUNT);
417 result = (apic_start - apic) * 1000L * tsc_khz /
423 printk(KERN_DEBUG "APIC timer calibration result %d\n", result);
425 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
426 result / 1000 / 1000, result / 1000 % 1000);
428 /* Calculate the scaled math multiplication factor */
429 lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC,
430 lapic_clockevent.shift);
431 lapic_clockevent.max_delta_ns =
432 clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
433 lapic_clockevent.min_delta_ns =
434 clockevent_delta2ns(0xF, &lapic_clockevent);
436 calibration_result = result / HZ;
440 * Setup the boot APIC
442 * Calibrate and verify the result.
444 void __init setup_boot_APIC_clock(void)
447 * The local apic timer can be disabled via the kernel commandline.
448 * Register the lapic timer as a dummy clock event source on SMP
449 * systems, so the broadcast mechanism is used. On UP systems simply
452 if (disable_apic_timer) {
453 printk(KERN_INFO "Disabling APIC timer\n");
454 /* No broadcast on UP ! */
455 if (num_possible_cpus() > 1) {
456 lapic_clockevent.mult = 1;
462 printk(KERN_INFO "Using local APIC timer interrupts.\n");
463 calibrate_APIC_clock();
466 * Do a sanity check on the APIC calibration result
468 if (calibration_result < (1000000 / HZ)) {
470 "APIC frequency too slow, disabling apic timer\n");
471 /* No broadcast on UP ! */
472 if (num_possible_cpus() > 1)
478 * If nmi_watchdog is set to IO_APIC, we need the
479 * PIT/HPET going. Otherwise register lapic as a dummy
482 if (nmi_watchdog != NMI_IO_APIC)
483 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
485 printk(KERN_WARNING "APIC timer registered as dummy,"
486 " due to nmi_watchdog=%d!\n", nmi_watchdog);
491 void __cpuinit setup_secondary_APIC_clock(void)
497 * The guts of the apic timer interrupt
499 static void local_apic_timer_interrupt(void)
501 int cpu = smp_processor_id();
502 struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
505 * Normally we should not be here till LAPIC has been initialized but
506 * in some cases like kdump, its possible that there is a pending LAPIC
507 * timer interrupt from previous kernel's context and is delivered in
508 * new kernel the moment interrupts are enabled.
510 * Interrupts are enabled early and LAPIC is setup much later, hence
511 * its possible that when we get here evt->event_handler is NULL.
512 * Check for event_handler being NULL and discard the interrupt as
515 if (!evt->event_handler) {
517 "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
519 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
524 * the NMI deadlock-detector uses this.
526 add_pda(apic_timer_irqs, 1);
528 evt->event_handler(evt);
532 * Local APIC timer interrupt. This is the most natural way for doing
533 * local interrupts, but local timer interrupts can be emulated by
534 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
536 * [ if a single-CPU system runs an SMP kernel then we call the local
537 * interrupt as well. Thus we cannot inline the local irq ... ]
539 void smp_apic_timer_interrupt(struct pt_regs *regs)
541 struct pt_regs *old_regs = set_irq_regs(regs);
544 * NOTE! We'd better ACK the irq immediately,
545 * because timer handling can be slow.
549 * update_process_times() expects us to have done irq_enter().
550 * Besides, if we don't timer interrupts ignore the global
551 * interrupt lock, which is the WrongThing (tm) to do.
555 local_apic_timer_interrupt();
557 set_irq_regs(old_regs);
560 int setup_profiling_timer(unsigned int multiplier)
567 * Local APIC start and shutdown
571 * clear_local_APIC - shutdown the local APIC
573 * This is called, when a CPU is disabled and before rebooting, so the state of
574 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
575 * leftovers during boot.
577 void clear_local_APIC(void)
582 /* APIC hasn't been mapped yet */
586 maxlvt = lapic_get_maxlvt();
588 * Masking an LVT entry can trigger a local APIC error
589 * if the vector is zero. Mask LVTERR first to prevent this.
592 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
593 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
596 * Careful: we have to set masks only first to deassert
597 * any level-triggered sources.
599 v = apic_read(APIC_LVTT);
600 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
601 v = apic_read(APIC_LVT0);
602 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
603 v = apic_read(APIC_LVT1);
604 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
606 v = apic_read(APIC_LVTPC);
607 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
611 * Clean APIC state for other OSs:
613 apic_write(APIC_LVTT, APIC_LVT_MASKED);
614 apic_write(APIC_LVT0, APIC_LVT_MASKED);
615 apic_write(APIC_LVT1, APIC_LVT_MASKED);
617 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
619 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
620 apic_write(APIC_ESR, 0);
625 * disable_local_APIC - clear and disable the local APIC
627 void disable_local_APIC(void)
634 * Disable APIC (implies clearing of registers
637 value = apic_read(APIC_SPIV);
638 value &= ~APIC_SPIV_APIC_ENABLED;
639 apic_write(APIC_SPIV, value);
642 void lapic_shutdown(void)
649 local_irq_save(flags);
651 disable_local_APIC();
653 local_irq_restore(flags);
657 * This is to verify that we're looking at a real local APIC.
658 * Check these against your board if the CPUs aren't getting
659 * started for no apparent reason.
661 int __init verify_local_APIC(void)
663 unsigned int reg0, reg1;
666 * The version register is read-only in a real APIC.
668 reg0 = apic_read(APIC_LVR);
669 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
670 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
671 reg1 = apic_read(APIC_LVR);
672 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
675 * The two version reads above should print the same
676 * numbers. If the second one is different, then we
677 * poke at a non-APIC.
683 * Check if the version looks reasonably.
685 reg1 = GET_APIC_VERSION(reg0);
686 if (reg1 == 0x00 || reg1 == 0xff)
688 reg1 = lapic_get_maxlvt();
689 if (reg1 < 0x02 || reg1 == 0xff)
693 * The ID register is read/write in a real APIC.
695 reg0 = apic_read(APIC_ID);
696 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
697 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
698 reg1 = apic_read(APIC_ID);
699 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
700 apic_write(APIC_ID, reg0);
701 if (reg1 != (reg0 ^ APIC_ID_MASK))
705 * The next two are just to see if we have sane values.
706 * They're only really relevant if we're in Virtual Wire
707 * compatibility mode, but most boxes are anymore.
709 reg0 = apic_read(APIC_LVT0);
710 apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
711 reg1 = apic_read(APIC_LVT1);
712 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
718 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
720 void __init sync_Arb_IDs(void)
722 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
729 apic_wait_icr_idle();
731 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
732 apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
737 * An initial setup of the virtual wire mode.
739 void __init init_bsp_APIC(void)
744 * Don't do the setup now if we have a SMP BIOS as the
745 * through-I/O-APIC virtual wire mode might be active.
747 if (smp_found_config || !cpu_has_apic)
750 value = apic_read(APIC_LVR);
753 * Do not trust the local APIC being empty at bootup.
760 value = apic_read(APIC_SPIV);
761 value &= ~APIC_VECTOR_MASK;
762 value |= APIC_SPIV_APIC_ENABLED;
763 value |= APIC_SPIV_FOCUS_DISABLED;
764 value |= SPURIOUS_APIC_VECTOR;
765 apic_write(APIC_SPIV, value);
768 * Set up the virtual wire mode.
770 apic_write(APIC_LVT0, APIC_DM_EXTINT);
772 apic_write(APIC_LVT1, value);
776 * setup_local_APIC - setup the local APIC
778 void __cpuinit setup_local_APIC(void)
784 value = apic_read(APIC_LVR);
786 BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);
789 * Double-check whether this APIC is really registered.
790 * This is meaningless in clustered apic mode, so we skip it.
792 if (!apic_id_registered())
796 * Intel recommends to set DFR, LDR and TPR before enabling
797 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
798 * document number 292116). So here it goes...
803 * Set Task Priority to 'accept all'. We never change this
806 value = apic_read(APIC_TASKPRI);
807 value &= ~APIC_TPRI_MASK;
808 apic_write(APIC_TASKPRI, value);
811 * After a crash, we no longer service the interrupts and a pending
812 * interrupt from previous kernel might still have ISR bit set.
814 * Most probably by now CPU has serviced that pending interrupt and
815 * it might not have done the ack_APIC_irq() because it thought,
816 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
817 * does not clear the ISR bit and cpu thinks it has already serivced
818 * the interrupt. Hence a vector might get locked. It was noticed
819 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
821 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
822 value = apic_read(APIC_ISR + i*0x10);
823 for (j = 31; j >= 0; j--) {
830 * Now that we are all set up, enable the APIC
832 value = apic_read(APIC_SPIV);
833 value &= ~APIC_VECTOR_MASK;
837 value |= APIC_SPIV_APIC_ENABLED;
839 /* We always use processor focus */
842 * Set spurious IRQ vector
844 value |= SPURIOUS_APIC_VECTOR;
845 apic_write(APIC_SPIV, value);
850 * set up through-local-APIC on the BP's LINT0. This is not
851 * strictly necessary in pure symmetric-IO mode, but sometimes
852 * we delegate interrupts to the 8259A.
855 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
857 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
858 if (!smp_processor_id() && !value) {
859 value = APIC_DM_EXTINT;
860 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
863 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
864 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
867 apic_write(APIC_LVT0, value);
870 * only the BP should see the LINT1 NMI signal, obviously.
872 if (!smp_processor_id())
875 value = APIC_DM_NMI | APIC_LVT_MASKED;
876 apic_write(APIC_LVT1, value);
880 static void __cpuinit lapic_setup_esr(void)
882 unsigned maxlvt = lapic_get_maxlvt();
884 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR);
886 * spec says clear errors after enabling vector.
889 apic_write(APIC_ESR, 0);
892 void __cpuinit end_local_APIC_setup(void)
895 setup_apic_nmi_watchdog(NULL);
900 * Detect and enable local APICs on non-SMP boards.
901 * Original code written by Keir Fraser.
902 * On AMD64 we trust the BIOS - if it says no APIC it is likely
903 * not correctly set up (usually the APIC timer won't work etc.)
905 static int __init detect_init_APIC(void)
908 printk(KERN_INFO "No local APIC present\n");
912 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
913 boot_cpu_physical_apicid = 0;
917 void __init early_init_lapic_mapping(void)
919 unsigned long phys_addr;
922 * If no local APIC can be found then go out
923 * : it means there is no mpatable and MADT
925 if (!smp_found_config)
928 phys_addr = mp_lapic_addr;
930 set_fixmap_nocache(FIX_APIC_BASE, phys_addr);
931 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
932 APIC_BASE, phys_addr);
935 * Fetch the APIC ID of the BSP in case we have a
936 * default configuration (or the MP table is broken).
938 boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id());
942 * init_apic_mappings - initialize APIC mappings
944 void __init init_apic_mappings(void)
947 * If no local APIC can be found then set up a fake all
948 * zeroes page to simulate the local APIC and another
949 * one for the IO-APIC.
951 if (!smp_found_config && detect_init_APIC()) {
952 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
953 apic_phys = __pa(apic_phys);
955 apic_phys = mp_lapic_addr;
957 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
958 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
959 APIC_BASE, apic_phys);
962 * Fetch the APIC ID of the BSP in case we have a
963 * default configuration (or the MP table is broken).
965 boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id());
969 * This initializes the IO-APIC and APIC hardware if this is
972 int __init APIC_init_uniprocessor(void)
975 printk(KERN_INFO "Apic disabled\n");
980 printk(KERN_INFO "Apic disabled by BIOS\n");
988 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
989 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
994 * Now enable IO-APICs, actually call clear_IO_APIC
995 * We need clear_IO_APIC before enabling vector on BP
997 if (!skip_ioapic_setup && nr_ioapics)
1000 if (!smp_found_config || skip_ioapic_setup || !nr_ioapics)
1001 localise_nmi_watchdog();
1002 end_local_APIC_setup();
1004 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1008 setup_boot_APIC_clock();
1009 check_nmi_watchdog();
1014 * Local APIC interrupts
1018 * This interrupt should _never_ happen with our APIC/SMP architecture
1020 asmlinkage void smp_spurious_interrupt(void)
1026 * Check if this really is a spurious interrupt and ACK it
1027 * if it is a vectored one. Just in case...
1028 * Spurious interrupts should not be ACKed.
1030 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1031 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1034 add_pda(irq_spurious_count, 1);
1039 * This interrupt should never happen with our APIC/SMP architecture
1041 asmlinkage void smp_error_interrupt(void)
1047 /* First tickle the hardware, only then report what went on. -- REW */
1048 v = apic_read(APIC_ESR);
1049 apic_write(APIC_ESR, 0);
1050 v1 = apic_read(APIC_ESR);
1052 atomic_inc(&irq_err_count);
1054 /* Here is what the APIC error bits mean:
1057 2: Send accept error
1058 3: Receive accept error
1060 5: Send illegal vector
1061 6: Received illegal vector
1062 7: Illegal register address
1064 printk(KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1065 smp_processor_id(), v , v1);
1070 * * connect_bsp_APIC - attach the APIC to the interrupt system
1072 void __init connect_bsp_APIC(void)
1077 void disconnect_bsp_APIC(int virt_wire_setup)
1079 /* Go back to Virtual Wire compatibility mode */
1080 unsigned long value;
1082 /* For the spurious interrupt use vector F, and enable it */
1083 value = apic_read(APIC_SPIV);
1084 value &= ~APIC_VECTOR_MASK;
1085 value |= APIC_SPIV_APIC_ENABLED;
1087 apic_write(APIC_SPIV, value);
1089 if (!virt_wire_setup) {
1091 * For LVT0 make it edge triggered, active high,
1092 * external and enabled
1094 value = apic_read(APIC_LVT0);
1095 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1096 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1097 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1098 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1099 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1100 apic_write(APIC_LVT0, value);
1103 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1106 /* For LVT1 make it edge triggered, active high, nmi and enabled */
1107 value = apic_read(APIC_LVT1);
1108 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1109 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1110 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1111 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1112 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1113 apic_write(APIC_LVT1, value);
1116 void __cpuinit generic_processor_info(int apicid, int version)
1121 if (num_processors >= NR_CPUS) {
1122 printk(KERN_WARNING "WARNING: NR_CPUS limit of %i reached."
1123 " Processor ignored.\n", NR_CPUS);
1127 if (num_processors >= maxcpus) {
1128 printk(KERN_WARNING "WARNING: maxcpus limit of %i reached."
1129 " Processor ignored.\n", maxcpus);
1134 cpus_complement(tmp_map, cpu_present_map);
1135 cpu = first_cpu(tmp_map);
1137 physid_set(apicid, phys_cpu_present_map);
1138 if (apicid == boot_cpu_physical_apicid) {
1140 * x86_bios_cpu_apicid is required to have processors listed
1141 * in same order as logical cpu numbers. Hence the first
1142 * entry is BSP, and so on.
1146 if (apicid > max_physical_apicid)
1147 max_physical_apicid = apicid;
1149 /* are we being called early in kernel startup? */
1150 if (early_per_cpu_ptr(x86_cpu_to_apicid)) {
1151 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
1152 u16 *bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
1154 cpu_to_apicid[cpu] = apicid;
1155 bios_cpu_apicid[cpu] = apicid;
1157 per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1158 per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1161 cpu_set(cpu, cpu_possible_map);
1162 cpu_set(cpu, cpu_present_map);
1165 int hard_smp_processor_id(void)
1167 return read_apic_id();
1176 /* 'active' is true if the local APIC was enabled by us and
1177 not the BIOS; this signifies that we are also responsible
1178 for disabling it before entering apm/acpi suspend */
1180 /* r/w apic fields */
1181 unsigned int apic_id;
1182 unsigned int apic_taskpri;
1183 unsigned int apic_ldr;
1184 unsigned int apic_dfr;
1185 unsigned int apic_spiv;
1186 unsigned int apic_lvtt;
1187 unsigned int apic_lvtpc;
1188 unsigned int apic_lvt0;
1189 unsigned int apic_lvt1;
1190 unsigned int apic_lvterr;
1191 unsigned int apic_tmict;
1192 unsigned int apic_tdcr;
1193 unsigned int apic_thmr;
1196 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1198 unsigned long flags;
1201 if (!apic_pm_state.active)
1204 maxlvt = lapic_get_maxlvt();
1206 apic_pm_state.apic_id = apic_read(APIC_ID);
1207 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1208 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1209 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1210 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
1211 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
1213 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
1214 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
1215 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
1216 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
1217 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
1218 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
1219 #ifdef CONFIG_X86_MCE_INTEL
1221 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
1223 local_irq_save(flags);
1224 disable_local_APIC();
1225 local_irq_restore(flags);
1229 static int lapic_resume(struct sys_device *dev)
1232 unsigned long flags;
1235 if (!apic_pm_state.active)
1238 maxlvt = lapic_get_maxlvt();
1240 local_irq_save(flags);
1241 rdmsr(MSR_IA32_APICBASE, l, h);
1242 l &= ~MSR_IA32_APICBASE_BASE;
1243 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
1244 wrmsr(MSR_IA32_APICBASE, l, h);
1245 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
1246 apic_write(APIC_ID, apic_pm_state.apic_id);
1247 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
1248 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
1249 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
1250 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
1251 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
1252 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
1253 #ifdef CONFIG_X86_MCE_INTEL
1255 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
1258 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
1259 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
1260 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
1261 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
1262 apic_write(APIC_ESR, 0);
1263 apic_read(APIC_ESR);
1264 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
1265 apic_write(APIC_ESR, 0);
1266 apic_read(APIC_ESR);
1267 local_irq_restore(flags);
1271 static struct sysdev_class lapic_sysclass = {
1273 .resume = lapic_resume,
1274 .suspend = lapic_suspend,
1277 static struct sys_device device_lapic = {
1279 .cls = &lapic_sysclass,
1282 static void __cpuinit apic_pm_activate(void)
1284 apic_pm_state.active = 1;
1287 static int __init init_lapic_sysfs(void)
1293 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
1295 error = sysdev_class_register(&lapic_sysclass);
1297 error = sysdev_register(&device_lapic);
1300 device_initcall(init_lapic_sysfs);
1302 #else /* CONFIG_PM */
1304 static void apic_pm_activate(void) { }
1306 #endif /* CONFIG_PM */
1309 * apic_is_clustered_box() -- Check if we can expect good TSC
1311 * Thus far, the major user of this is IBM's Summit2 series:
1313 * Clustered boxes may have unsynced TSC problems if they are
1314 * multi-chassis. Use available data to take a good guess.
1315 * If in doubt, go HPET.
1317 __cpuinit int apic_is_clustered_box(void)
1319 int i, clusters, zeros;
1321 u16 *bios_cpu_apicid;
1322 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
1325 * there is not this kind of box with AMD CPU yet.
1326 * Some AMD box with quadcore cpu and 8 sockets apicid
1327 * will be [4, 0x23] or [8, 0x27] could be thought to
1328 * vsmp box still need checking...
1330 if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && !is_vsmp_box())
1333 bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
1334 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
1336 for (i = 0; i < NR_CPUS; i++) {
1337 /* are we being called early in kernel startup? */
1338 if (bios_cpu_apicid) {
1339 id = bios_cpu_apicid[i];
1341 else if (i < nr_cpu_ids) {
1343 id = per_cpu(x86_bios_cpu_apicid, i);
1350 if (id != BAD_APICID)
1351 __set_bit(APIC_CLUSTERID(id), clustermap);
1354 /* Problem: Partially populated chassis may not have CPUs in some of
1355 * the APIC clusters they have been allocated. Only present CPUs have
1356 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
1357 * Since clusters are allocated sequentially, count zeros only if
1358 * they are bounded by ones.
1362 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
1363 if (test_bit(i, clustermap)) {
1364 clusters += 1 + zeros;
1370 /* ScaleMP vSMPowered boxes have one cluster per board and TSCs are
1371 * not guaranteed to be synced between boards
1373 if (is_vsmp_box() && clusters > 1)
1377 * If clusters > 2, then should be multi-chassis.
1378 * May have to revisit this when multi-core + hyperthreaded CPUs come
1379 * out, but AFAIK this will work even for them.
1381 return (clusters > 2);
1385 * APIC command line parameters
1387 static int __init apic_set_verbosity(char *str)
1390 skip_ioapic_setup = 0;
1394 if (strcmp("debug", str) == 0)
1395 apic_verbosity = APIC_DEBUG;
1396 else if (strcmp("verbose", str) == 0)
1397 apic_verbosity = APIC_VERBOSE;
1399 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
1400 " use apic=verbose or apic=debug\n", str);
1406 early_param("apic", apic_set_verbosity);
1408 static __init int setup_disableapic(char *str)
1411 clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1414 early_param("disableapic", setup_disableapic);
1416 /* same as disableapic, for compatibility */
1417 static __init int setup_nolapic(char *str)
1419 return setup_disableapic(str);
1421 early_param("nolapic", setup_nolapic);
1423 static int __init parse_lapic_timer_c2_ok(char *arg)
1425 local_apic_timer_c2_ok = 1;
1428 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
1430 static __init int setup_noapictimer(char *str)
1432 if (str[0] != ' ' && str[0] != 0)
1434 disable_apic_timer = 1;
1437 __setup("noapictimer", setup_noapictimer);
1439 static __init int setup_apicpmtimer(char *s)
1441 apic_calibrate_pmtmr = 1;
1445 __setup("apicpmtimer", setup_apicpmtimer);
1447 static int __init lapic_insert_resource(void)
1452 /* Put local APIC into the resource map. */
1453 lapic_resource.start = apic_phys;
1454 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
1455 insert_resource(&iomem_resource, &lapic_resource);
1461 * need call insert after e820_reserve_resources()
1462 * that is using request_resource
1464 late_initcall(lapic_insert_resource);