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;
50 /* Local APIC timer works in C2 */
51 int local_apic_timer_c2_ok;
52 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
55 * Debug level, exported for io_apic.c
57 unsigned int apic_verbosity;
59 /* Have we found an MP table */
62 static struct resource lapic_resource = {
64 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
67 static unsigned int calibration_result;
69 static int lapic_next_event(unsigned long delta,
70 struct clock_event_device *evt);
71 static void lapic_timer_setup(enum clock_event_mode mode,
72 struct clock_event_device *evt);
73 static void lapic_timer_broadcast(cpumask_t mask);
74 static void apic_pm_activate(void);
76 static struct clock_event_device lapic_clockevent = {
78 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
79 | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
81 .set_mode = lapic_timer_setup,
82 .set_next_event = lapic_next_event,
83 .broadcast = lapic_timer_broadcast,
87 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
89 static unsigned long apic_phys;
91 unsigned long mp_lapic_addr;
93 unsigned int __cpuinitdata maxcpus = NR_CPUS;
95 * Get the LAPIC version
97 static inline int lapic_get_version(void)
99 return GET_APIC_VERSION(apic_read(APIC_LVR));
103 * Check, if the APIC is integrated or a seperate chip
105 static inline int lapic_is_integrated(void)
111 * Check, whether this is a modern or a first generation APIC
113 static int modern_apic(void)
115 /* AMD systems use old APIC versions, so check the CPU */
116 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
117 boot_cpu_data.x86 >= 0xf)
119 return lapic_get_version() >= 0x14;
122 void apic_wait_icr_idle(void)
124 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
128 u32 safe_apic_wait_icr_idle(void)
135 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
139 } while (timeout++ < 1000);
145 * enable_NMI_through_LVT0 - enable NMI through local vector table 0
147 void __cpuinit enable_NMI_through_LVT0(void)
151 /* unmask and set to NMI */
154 /* Level triggered for 82489DX (32bit mode) */
155 if (!lapic_is_integrated())
156 v |= APIC_LVT_LEVEL_TRIGGER;
158 apic_write(APIC_LVT0, v);
162 * lapic_get_maxlvt - get the maximum number of local vector table entries
164 int lapic_get_maxlvt(void)
168 v = apic_read(APIC_LVR);
170 * - we always have APIC integrated on 64bit mode
171 * - 82489DXs do not report # of LVT entries
173 return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
177 * This function sets up the local APIC timer, with a timeout of
178 * 'clocks' APIC bus clock. During calibration we actually call
179 * this function twice on the boot CPU, once with a bogus timeout
180 * value, second time for real. The other (noncalibrating) CPUs
181 * call this function only once, with the real, calibrated value.
183 * We do reads before writes even if unnecessary, to get around the
184 * P5 APIC double write bug.
187 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
189 unsigned int lvtt_value, tmp_value;
191 lvtt_value = LOCAL_TIMER_VECTOR;
193 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
195 lvtt_value |= APIC_LVT_MASKED;
197 apic_write(APIC_LVTT, lvtt_value);
202 tmp_value = apic_read(APIC_TDCR);
203 apic_write(APIC_TDCR, (tmp_value
204 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
208 apic_write(APIC_TMICT, clocks);
212 * Setup extended LVT, AMD specific (K8, family 10h)
214 * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
215 * MCE interrupts are supported. Thus MCE offset must be set to 0.
218 #define APIC_EILVT_LVTOFF_MCE 0
219 #define APIC_EILVT_LVTOFF_IBS 1
221 static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
223 unsigned long reg = (lvt_off << 4) + APIC_EILVT0;
224 unsigned int v = (mask << 16) | (msg_type << 8) | vector;
229 u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
231 setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
232 return APIC_EILVT_LVTOFF_MCE;
235 u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
237 setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
238 return APIC_EILVT_LVTOFF_IBS;
242 * Program the next event, relative to now
244 static int lapic_next_event(unsigned long delta,
245 struct clock_event_device *evt)
247 apic_write(APIC_TMICT, delta);
252 * Setup the lapic timer in periodic or oneshot mode
254 static void lapic_timer_setup(enum clock_event_mode mode,
255 struct clock_event_device *evt)
260 /* Lapic used as dummy for broadcast ? */
261 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
264 local_irq_save(flags);
267 case CLOCK_EVT_MODE_PERIODIC:
268 case CLOCK_EVT_MODE_ONESHOT:
269 __setup_APIC_LVTT(calibration_result,
270 mode != CLOCK_EVT_MODE_PERIODIC, 1);
272 case CLOCK_EVT_MODE_UNUSED:
273 case CLOCK_EVT_MODE_SHUTDOWN:
274 v = apic_read(APIC_LVTT);
275 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
276 apic_write(APIC_LVTT, v);
278 case CLOCK_EVT_MODE_RESUME:
279 /* Nothing to do here */
283 local_irq_restore(flags);
287 * Local APIC timer broadcast function
289 static void lapic_timer_broadcast(cpumask_t mask)
292 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
297 * Setup the local APIC timer for this CPU. Copy the initilized values
298 * of the boot CPU and register the clock event in the framework.
300 static void setup_APIC_timer(void)
302 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
304 memcpy(levt, &lapic_clockevent, sizeof(*levt));
305 levt->cpumask = cpumask_of_cpu(smp_processor_id());
307 clockevents_register_device(levt);
311 * In this function we calibrate APIC bus clocks to the external
312 * timer. Unfortunately we cannot use jiffies and the timer irq
313 * to calibrate, since some later bootup code depends on getting
314 * the first irq? Ugh.
316 * We want to do the calibration only once since we
317 * want to have local timer irqs syncron. CPUs connected
318 * by the same APIC bus have the very same bus frequency.
319 * And we want to have irqs off anyways, no accidental
323 #define TICK_COUNT 100000000
325 static int __init calibrate_APIC_clock(void)
327 unsigned apic, apic_start;
328 unsigned long tsc, tsc_start;
334 * Put whatever arbitrary (but long enough) timeout
335 * value into the APIC clock, we just want to get the
336 * counter running for calibration.
338 * No interrupt enable !
340 __setup_APIC_LVTT(250000000, 0, 0);
342 apic_start = apic_read(APIC_TMCCT);
343 #ifdef CONFIG_X86_PM_TIMER
344 if (apic_calibrate_pmtmr && pmtmr_ioport) {
345 pmtimer_wait(5000); /* 5ms wait */
346 apic = apic_read(APIC_TMCCT);
347 result = (apic_start - apic) * 1000L / 5;
354 apic = apic_read(APIC_TMCCT);
356 } while ((tsc - tsc_start) < TICK_COUNT &&
357 (apic_start - apic) < TICK_COUNT);
359 result = (apic_start - apic) * 1000L * tsc_khz /
365 printk(KERN_DEBUG "APIC timer calibration result %d\n", result);
367 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
368 result / 1000 / 1000, result / 1000 % 1000);
370 /* Calculate the scaled math multiplication factor */
371 lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC,
372 lapic_clockevent.shift);
373 lapic_clockevent.max_delta_ns =
374 clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
375 lapic_clockevent.min_delta_ns =
376 clockevent_delta2ns(0xF, &lapic_clockevent);
378 calibration_result = result / HZ;
381 * Do a sanity check on the APIC calibration result
383 if (calibration_result < (1000000 / HZ)) {
385 "APIC frequency too slow, disabling apic timer\n");
393 * Setup the boot APIC
395 * Calibrate and verify the result.
397 void __init setup_boot_APIC_clock(void)
400 * The local apic timer can be disabled via the kernel commandline.
401 * Register the lapic timer as a dummy clock event source on SMP
402 * systems, so the broadcast mechanism is used. On UP systems simply
405 if (disable_apic_timer) {
406 printk(KERN_INFO "Disabling APIC timer\n");
407 /* No broadcast on UP ! */
408 if (num_possible_cpus() > 1) {
409 lapic_clockevent.mult = 1;
415 printk(KERN_INFO "Using local APIC timer interrupts.\n");
416 if (calibrate_APIC_clock()) {
417 /* No broadcast on UP ! */
418 if (num_possible_cpus() > 1)
424 * If nmi_watchdog is set to IO_APIC, we need the
425 * PIT/HPET going. Otherwise register lapic as a dummy
428 if (nmi_watchdog != NMI_IO_APIC)
429 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
431 printk(KERN_WARNING "APIC timer registered as dummy,"
432 " due to nmi_watchdog=%d!\n", nmi_watchdog);
437 void __cpuinit setup_secondary_APIC_clock(void)
443 * The guts of the apic timer interrupt
445 static void local_apic_timer_interrupt(void)
447 int cpu = smp_processor_id();
448 struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
451 * Normally we should not be here till LAPIC has been initialized but
452 * in some cases like kdump, its possible that there is a pending LAPIC
453 * timer interrupt from previous kernel's context and is delivered in
454 * new kernel the moment interrupts are enabled.
456 * Interrupts are enabled early and LAPIC is setup much later, hence
457 * its possible that when we get here evt->event_handler is NULL.
458 * Check for event_handler being NULL and discard the interrupt as
461 if (!evt->event_handler) {
463 "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
465 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
470 * the NMI deadlock-detector uses this.
472 add_pda(apic_timer_irqs, 1);
474 evt->event_handler(evt);
478 * Local APIC timer interrupt. This is the most natural way for doing
479 * local interrupts, but local timer interrupts can be emulated by
480 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
482 * [ if a single-CPU system runs an SMP kernel then we call the local
483 * interrupt as well. Thus we cannot inline the local irq ... ]
485 void smp_apic_timer_interrupt(struct pt_regs *regs)
487 struct pt_regs *old_regs = set_irq_regs(regs);
490 * NOTE! We'd better ACK the irq immediately,
491 * because timer handling can be slow.
495 * update_process_times() expects us to have done irq_enter().
496 * Besides, if we don't timer interrupts ignore the global
497 * interrupt lock, which is the WrongThing (tm) to do.
501 local_apic_timer_interrupt();
503 set_irq_regs(old_regs);
506 int setup_profiling_timer(unsigned int multiplier)
513 * Local APIC start and shutdown
517 * clear_local_APIC - shutdown the local APIC
519 * This is called, when a CPU is disabled and before rebooting, so the state of
520 * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
521 * leftovers during boot.
523 void clear_local_APIC(void)
528 /* APIC hasn't been mapped yet */
532 maxlvt = lapic_get_maxlvt();
534 * Masking an LVT entry can trigger a local APIC error
535 * if the vector is zero. Mask LVTERR first to prevent this.
538 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
539 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
542 * Careful: we have to set masks only first to deassert
543 * any level-triggered sources.
545 v = apic_read(APIC_LVTT);
546 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
547 v = apic_read(APIC_LVT0);
548 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
549 v = apic_read(APIC_LVT1);
550 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
552 v = apic_read(APIC_LVTPC);
553 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
557 * Clean APIC state for other OSs:
559 apic_write(APIC_LVTT, APIC_LVT_MASKED);
560 apic_write(APIC_LVT0, APIC_LVT_MASKED);
561 apic_write(APIC_LVT1, APIC_LVT_MASKED);
563 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
565 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
566 apic_write(APIC_ESR, 0);
571 * disable_local_APIC - clear and disable the local APIC
573 void disable_local_APIC(void)
580 * Disable APIC (implies clearing of registers
583 value = apic_read(APIC_SPIV);
584 value &= ~APIC_SPIV_APIC_ENABLED;
585 apic_write(APIC_SPIV, value);
588 void lapic_shutdown(void)
595 local_irq_save(flags);
597 disable_local_APIC();
599 local_irq_restore(flags);
603 * This is to verify that we're looking at a real local APIC.
604 * Check these against your board if the CPUs aren't getting
605 * started for no apparent reason.
607 int __init verify_local_APIC(void)
609 unsigned int reg0, reg1;
612 * The version register is read-only in a real APIC.
614 reg0 = apic_read(APIC_LVR);
615 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
616 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
617 reg1 = apic_read(APIC_LVR);
618 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
621 * The two version reads above should print the same
622 * numbers. If the second one is different, then we
623 * poke at a non-APIC.
629 * Check if the version looks reasonably.
631 reg1 = GET_APIC_VERSION(reg0);
632 if (reg1 == 0x00 || reg1 == 0xff)
634 reg1 = lapic_get_maxlvt();
635 if (reg1 < 0x02 || reg1 == 0xff)
639 * The ID register is read/write in a real APIC.
641 reg0 = read_apic_id();
642 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
643 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
644 reg1 = read_apic_id();
645 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
646 apic_write(APIC_ID, reg0);
647 if (reg1 != (reg0 ^ APIC_ID_MASK))
651 * The next two are just to see if we have sane values.
652 * They're only really relevant if we're in Virtual Wire
653 * compatibility mode, but most boxes are anymore.
655 reg0 = apic_read(APIC_LVT0);
656 apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
657 reg1 = apic_read(APIC_LVT1);
658 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
664 * sync_Arb_IDs - synchronize APIC bus arbitration IDs
666 void __init sync_Arb_IDs(void)
668 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
675 apic_wait_icr_idle();
677 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
678 apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
683 * An initial setup of the virtual wire mode.
685 void __init init_bsp_APIC(void)
690 * Don't do the setup now if we have a SMP BIOS as the
691 * through-I/O-APIC virtual wire mode might be active.
693 if (smp_found_config || !cpu_has_apic)
696 value = apic_read(APIC_LVR);
699 * Do not trust the local APIC being empty at bootup.
706 value = apic_read(APIC_SPIV);
707 value &= ~APIC_VECTOR_MASK;
708 value |= APIC_SPIV_APIC_ENABLED;
709 value |= APIC_SPIV_FOCUS_DISABLED;
710 value |= SPURIOUS_APIC_VECTOR;
711 apic_write(APIC_SPIV, value);
714 * Set up the virtual wire mode.
716 apic_write(APIC_LVT0, APIC_DM_EXTINT);
718 apic_write(APIC_LVT1, value);
722 * setup_local_APIC - setup the local APIC
724 void __cpuinit setup_local_APIC(void)
730 value = apic_read(APIC_LVR);
732 BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);
735 * Double-check whether this APIC is really registered.
736 * This is meaningless in clustered apic mode, so we skip it.
738 if (!apic_id_registered())
742 * Intel recommends to set DFR, LDR and TPR before enabling
743 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
744 * document number 292116). So here it goes...
749 * Set Task Priority to 'accept all'. We never change this
752 value = apic_read(APIC_TASKPRI);
753 value &= ~APIC_TPRI_MASK;
754 apic_write(APIC_TASKPRI, value);
757 * After a crash, we no longer service the interrupts and a pending
758 * interrupt from previous kernel might still have ISR bit set.
760 * Most probably by now CPU has serviced that pending interrupt and
761 * it might not have done the ack_APIC_irq() because it thought,
762 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
763 * does not clear the ISR bit and cpu thinks it has already serivced
764 * the interrupt. Hence a vector might get locked. It was noticed
765 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
767 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
768 value = apic_read(APIC_ISR + i*0x10);
769 for (j = 31; j >= 0; j--) {
776 * Now that we are all set up, enable the APIC
778 value = apic_read(APIC_SPIV);
779 value &= ~APIC_VECTOR_MASK;
783 value |= APIC_SPIV_APIC_ENABLED;
785 /* We always use processor focus */
788 * Set spurious IRQ vector
790 value |= SPURIOUS_APIC_VECTOR;
791 apic_write(APIC_SPIV, value);
796 * set up through-local-APIC on the BP's LINT0. This is not
797 * strictly necessary in pure symmetric-IO mode, but sometimes
798 * we delegate interrupts to the 8259A.
801 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
803 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
804 if (!smp_processor_id() && !value) {
805 value = APIC_DM_EXTINT;
806 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
809 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
810 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
813 apic_write(APIC_LVT0, value);
816 * only the BP should see the LINT1 NMI signal, obviously.
818 if (!smp_processor_id())
821 value = APIC_DM_NMI | APIC_LVT_MASKED;
822 apic_write(APIC_LVT1, value);
826 static void __cpuinit lapic_setup_esr(void)
828 unsigned maxlvt = lapic_get_maxlvt();
830 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR);
832 * spec says clear errors after enabling vector.
835 apic_write(APIC_ESR, 0);
838 void __cpuinit end_local_APIC_setup(void)
841 setup_apic_nmi_watchdog(NULL);
846 * Detect and enable local APICs on non-SMP boards.
847 * Original code written by Keir Fraser.
848 * On AMD64 we trust the BIOS - if it says no APIC it is likely
849 * not correctly set up (usually the APIC timer won't work etc.)
851 static int __init detect_init_APIC(void)
854 printk(KERN_INFO "No local APIC present\n");
858 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
859 boot_cpu_physical_apicid = 0;
863 void __init early_init_lapic_mapping(void)
865 unsigned long phys_addr;
868 * If no local APIC can be found then go out
869 * : it means there is no mpatable and MADT
871 if (!smp_found_config)
874 phys_addr = mp_lapic_addr;
876 set_fixmap_nocache(FIX_APIC_BASE, phys_addr);
877 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
878 APIC_BASE, phys_addr);
881 * Fetch the APIC ID of the BSP in case we have a
882 * default configuration (or the MP table is broken).
884 boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id());
888 * init_apic_mappings - initialize APIC mappings
890 void __init init_apic_mappings(void)
893 * If no local APIC can be found then set up a fake all
894 * zeroes page to simulate the local APIC and another
895 * one for the IO-APIC.
897 if (!smp_found_config && detect_init_APIC()) {
898 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
899 apic_phys = __pa(apic_phys);
901 apic_phys = mp_lapic_addr;
903 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
904 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
905 APIC_BASE, apic_phys);
908 * Fetch the APIC ID of the BSP in case we have a
909 * default configuration (or the MP table is broken).
911 boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id());
915 * This initializes the IO-APIC and APIC hardware if this is
918 int __init APIC_init_uniprocessor(void)
921 printk(KERN_INFO "Apic disabled\n");
926 printk(KERN_INFO "Apic disabled by BIOS\n");
934 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
935 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
940 * Now enable IO-APICs, actually call clear_IO_APIC
941 * We need clear_IO_APIC before enabling vector on BP
943 if (!skip_ioapic_setup && nr_ioapics)
946 if (!smp_found_config || skip_ioapic_setup || !nr_ioapics)
947 localise_nmi_watchdog();
948 end_local_APIC_setup();
950 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
954 setup_boot_APIC_clock();
955 check_nmi_watchdog();
960 * Local APIC interrupts
964 * This interrupt should _never_ happen with our APIC/SMP architecture
966 asmlinkage void smp_spurious_interrupt(void)
972 * Check if this really is a spurious interrupt and ACK it
973 * if it is a vectored one. Just in case...
974 * Spurious interrupts should not be ACKed.
976 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
977 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
980 add_pda(irq_spurious_count, 1);
985 * This interrupt should never happen with our APIC/SMP architecture
987 asmlinkage void smp_error_interrupt(void)
993 /* First tickle the hardware, only then report what went on. -- REW */
994 v = apic_read(APIC_ESR);
995 apic_write(APIC_ESR, 0);
996 v1 = apic_read(APIC_ESR);
998 atomic_inc(&irq_err_count);
1000 /* Here is what the APIC error bits mean:
1003 2: Send accept error
1004 3: Receive accept error
1006 5: Send illegal vector
1007 6: Received illegal vector
1008 7: Illegal register address
1010 printk(KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1011 smp_processor_id(), v , v1);
1016 * * connect_bsp_APIC - attach the APIC to the interrupt system
1018 void __init connect_bsp_APIC(void)
1023 void disconnect_bsp_APIC(int virt_wire_setup)
1025 /* Go back to Virtual Wire compatibility mode */
1026 unsigned long value;
1028 /* For the spurious interrupt use vector F, and enable it */
1029 value = apic_read(APIC_SPIV);
1030 value &= ~APIC_VECTOR_MASK;
1031 value |= APIC_SPIV_APIC_ENABLED;
1033 apic_write(APIC_SPIV, value);
1035 if (!virt_wire_setup) {
1037 * For LVT0 make it edge triggered, active high,
1038 * external and enabled
1040 value = apic_read(APIC_LVT0);
1041 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1042 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1043 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1044 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1045 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1046 apic_write(APIC_LVT0, value);
1049 apic_write(APIC_LVT0, APIC_LVT_MASKED);
1052 /* For LVT1 make it edge triggered, active high, nmi and enabled */
1053 value = apic_read(APIC_LVT1);
1054 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1055 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1056 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1057 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1058 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1059 apic_write(APIC_LVT1, value);
1062 void __cpuinit generic_processor_info(int apicid, int version)
1067 if (num_processors >= NR_CPUS) {
1068 printk(KERN_WARNING "WARNING: NR_CPUS limit of %i reached."
1069 " Processor ignored.\n", NR_CPUS);
1073 if (num_processors >= maxcpus) {
1074 printk(KERN_WARNING "WARNING: maxcpus limit of %i reached."
1075 " Processor ignored.\n", maxcpus);
1080 cpus_complement(tmp_map, cpu_present_map);
1081 cpu = first_cpu(tmp_map);
1083 physid_set(apicid, phys_cpu_present_map);
1084 if (apicid == boot_cpu_physical_apicid) {
1086 * x86_bios_cpu_apicid is required to have processors listed
1087 * in same order as logical cpu numbers. Hence the first
1088 * entry is BSP, and so on.
1092 if (apicid > max_physical_apicid)
1093 max_physical_apicid = apicid;
1095 /* are we being called early in kernel startup? */
1096 if (early_per_cpu_ptr(x86_cpu_to_apicid)) {
1097 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
1098 u16 *bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
1100 cpu_to_apicid[cpu] = apicid;
1101 bios_cpu_apicid[cpu] = apicid;
1103 per_cpu(x86_cpu_to_apicid, cpu) = apicid;
1104 per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
1107 cpu_set(cpu, cpu_possible_map);
1108 cpu_set(cpu, cpu_present_map);
1117 /* 'active' is true if the local APIC was enabled by us and
1118 not the BIOS; this signifies that we are also responsible
1119 for disabling it before entering apm/acpi suspend */
1121 /* r/w apic fields */
1122 unsigned int apic_id;
1123 unsigned int apic_taskpri;
1124 unsigned int apic_ldr;
1125 unsigned int apic_dfr;
1126 unsigned int apic_spiv;
1127 unsigned int apic_lvtt;
1128 unsigned int apic_lvtpc;
1129 unsigned int apic_lvt0;
1130 unsigned int apic_lvt1;
1131 unsigned int apic_lvterr;
1132 unsigned int apic_tmict;
1133 unsigned int apic_tdcr;
1134 unsigned int apic_thmr;
1137 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
1139 unsigned long flags;
1142 if (!apic_pm_state.active)
1145 maxlvt = lapic_get_maxlvt();
1147 apic_pm_state.apic_id = read_apic_id();
1148 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
1149 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
1150 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
1151 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
1152 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
1154 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
1155 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
1156 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
1157 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
1158 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
1159 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
1160 #ifdef CONFIG_X86_MCE_INTEL
1162 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
1164 local_irq_save(flags);
1165 disable_local_APIC();
1166 local_irq_restore(flags);
1170 static int lapic_resume(struct sys_device *dev)
1173 unsigned long flags;
1176 if (!apic_pm_state.active)
1179 maxlvt = lapic_get_maxlvt();
1181 local_irq_save(flags);
1182 rdmsr(MSR_IA32_APICBASE, l, h);
1183 l &= ~MSR_IA32_APICBASE_BASE;
1184 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
1185 wrmsr(MSR_IA32_APICBASE, l, h);
1186 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
1187 apic_write(APIC_ID, apic_pm_state.apic_id);
1188 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
1189 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
1190 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
1191 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
1192 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
1193 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
1194 #ifdef CONFIG_X86_MCE_INTEL
1196 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
1199 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
1200 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
1201 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
1202 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
1203 apic_write(APIC_ESR, 0);
1204 apic_read(APIC_ESR);
1205 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
1206 apic_write(APIC_ESR, 0);
1207 apic_read(APIC_ESR);
1208 local_irq_restore(flags);
1212 static struct sysdev_class lapic_sysclass = {
1214 .resume = lapic_resume,
1215 .suspend = lapic_suspend,
1218 static struct sys_device device_lapic = {
1220 .cls = &lapic_sysclass,
1223 static void __cpuinit apic_pm_activate(void)
1225 apic_pm_state.active = 1;
1228 static int __init init_lapic_sysfs(void)
1234 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
1236 error = sysdev_class_register(&lapic_sysclass);
1238 error = sysdev_register(&device_lapic);
1241 device_initcall(init_lapic_sysfs);
1243 #else /* CONFIG_PM */
1245 static void apic_pm_activate(void) { }
1247 #endif /* CONFIG_PM */
1250 * apic_is_clustered_box() -- Check if we can expect good TSC
1252 * Thus far, the major user of this is IBM's Summit2 series:
1254 * Clustered boxes may have unsynced TSC problems if they are
1255 * multi-chassis. Use available data to take a good guess.
1256 * If in doubt, go HPET.
1258 __cpuinit int apic_is_clustered_box(void)
1260 int i, clusters, zeros;
1262 u16 *bios_cpu_apicid;
1263 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
1266 * there is not this kind of box with AMD CPU yet.
1267 * Some AMD box with quadcore cpu and 8 sockets apicid
1268 * will be [4, 0x23] or [8, 0x27] could be thought to
1269 * vsmp box still need checking...
1271 if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && !is_vsmp_box())
1274 bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
1275 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
1277 for (i = 0; i < NR_CPUS; i++) {
1278 /* are we being called early in kernel startup? */
1279 if (bios_cpu_apicid) {
1280 id = bios_cpu_apicid[i];
1282 else if (i < nr_cpu_ids) {
1284 id = per_cpu(x86_bios_cpu_apicid, i);
1291 if (id != BAD_APICID)
1292 __set_bit(APIC_CLUSTERID(id), clustermap);
1295 /* Problem: Partially populated chassis may not have CPUs in some of
1296 * the APIC clusters they have been allocated. Only present CPUs have
1297 * x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
1298 * Since clusters are allocated sequentially, count zeros only if
1299 * they are bounded by ones.
1303 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
1304 if (test_bit(i, clustermap)) {
1305 clusters += 1 + zeros;
1311 /* ScaleMP vSMPowered boxes have one cluster per board and TSCs are
1312 * not guaranteed to be synced between boards
1314 if (is_vsmp_box() && clusters > 1)
1318 * If clusters > 2, then should be multi-chassis.
1319 * May have to revisit this when multi-core + hyperthreaded CPUs come
1320 * out, but AFAIK this will work even for them.
1322 return (clusters > 2);
1326 * APIC command line parameters
1328 static int __init apic_set_verbosity(char *str)
1331 skip_ioapic_setup = 0;
1335 if (strcmp("debug", str) == 0)
1336 apic_verbosity = APIC_DEBUG;
1337 else if (strcmp("verbose", str) == 0)
1338 apic_verbosity = APIC_VERBOSE;
1340 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
1341 " use apic=verbose or apic=debug\n", str);
1347 early_param("apic", apic_set_verbosity);
1349 static __init int setup_disableapic(char *str)
1352 setup_clear_cpu_cap(X86_FEATURE_APIC);
1355 early_param("disableapic", setup_disableapic);
1357 /* same as disableapic, for compatibility */
1358 static __init int setup_nolapic(char *str)
1360 return setup_disableapic(str);
1362 early_param("nolapic", setup_nolapic);
1364 static int __init parse_lapic_timer_c2_ok(char *arg)
1366 local_apic_timer_c2_ok = 1;
1369 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
1371 static __init int setup_noapictimer(char *str)
1373 if (str[0] != ' ' && str[0] != 0)
1375 disable_apic_timer = 1;
1378 __setup("noapictimer", setup_noapictimer);
1380 static __init int setup_apicpmtimer(char *s)
1382 apic_calibrate_pmtmr = 1;
1386 __setup("apicpmtimer", setup_apicpmtimer);
1388 static int __init lapic_insert_resource(void)
1393 /* Put local APIC into the resource map. */
1394 lapic_resource.start = apic_phys;
1395 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
1396 insert_resource(&iomem_resource, &lapic_resource);
1402 * need call insert after e820_reserve_resources()
1403 * that is using request_resource
1405 late_initcall(lapic_insert_resource);