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/module.h>
27 #include <linux/ioport.h>
28 #include <linux/clockchips.h>
29 #include <linux/acpi_pmtmr.h>
31 #include <asm/atomic.h>
34 #include <asm/mpspec.h>
35 #include <asm/pgalloc.h>
36 #include <asm/mach_apic.h>
39 #include <asm/proto.h>
40 #include <asm/timex.h>
45 int disable_apic_timer __cpuinitdata;
46 static int apic_calibrate_pmtmr __initdata;
48 /* Local APIC timer works in C2? */
49 int local_apic_timer_c2_ok;
50 EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
52 static struct resource *ioapic_resources;
53 static struct resource lapic_resource = {
55 .flags = IORESOURCE_MEM | IORESOURCE_BUSY,
58 static unsigned int calibration_result;
60 static int lapic_next_event(unsigned long delta,
61 struct clock_event_device *evt);
62 static void lapic_timer_setup(enum clock_event_mode mode,
63 struct clock_event_device *evt);
65 static void lapic_timer_broadcast(cpumask_t mask);
67 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen);
69 static struct clock_event_device lapic_clockevent = {
71 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
72 | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
74 .set_mode = lapic_timer_setup,
75 .set_next_event = lapic_next_event,
76 .broadcast = lapic_timer_broadcast,
80 static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
82 static int lapic_next_event(unsigned long delta,
83 struct clock_event_device *evt)
85 apic_write(APIC_TMICT, delta);
89 static void lapic_timer_setup(enum clock_event_mode mode,
90 struct clock_event_device *evt)
95 /* Lapic used as dummy for broadcast ? */
96 if (evt->features & CLOCK_EVT_FEAT_DUMMY)
99 local_irq_save(flags);
102 case CLOCK_EVT_MODE_PERIODIC:
103 case CLOCK_EVT_MODE_ONESHOT:
104 __setup_APIC_LVTT(calibration_result,
105 mode != CLOCK_EVT_MODE_PERIODIC, 1);
107 case CLOCK_EVT_MODE_UNUSED:
108 case CLOCK_EVT_MODE_SHUTDOWN:
109 v = apic_read(APIC_LVTT);
110 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
111 apic_write(APIC_LVTT, v);
113 case CLOCK_EVT_MODE_RESUME:
114 /* Nothing to do here */
118 local_irq_restore(flags);
122 * Local APIC timer broadcast function
124 static void lapic_timer_broadcast(cpumask_t mask)
127 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
131 static void apic_pm_activate(void);
133 void apic_wait_icr_idle(void)
135 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
139 u32 safe_apic_wait_icr_idle(void)
146 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
150 } while (timeout++ < 1000);
155 void enable_NMI_through_LVT0 (void * dummy)
159 /* unmask and set to NMI */
161 apic_write(APIC_LVT0, v);
164 int lapic_get_maxlvt(void)
166 unsigned int v, maxlvt;
168 v = apic_read(APIC_LVR);
169 maxlvt = GET_APIC_MAXLVT(v);
174 * 'what should we do if we get a hw irq event on an illegal vector'.
175 * each architecture has to answer this themselves.
177 void ack_bad_irq(unsigned int irq)
179 printk("unexpected IRQ trap at vector %02x\n", irq);
181 * Currently unexpected vectors happen only on SMP and APIC.
182 * We _must_ ack these because every local APIC has only N
183 * irq slots per priority level, and a 'hanging, unacked' IRQ
184 * holds up an irq slot - in excessive cases (when multiple
185 * unexpected vectors occur) that might lock up the APIC
187 * But don't ack when the APIC is disabled. -AK
193 void clear_local_APIC(void)
198 maxlvt = lapic_get_maxlvt();
201 * Masking an LVT entry can trigger a local APIC error
202 * if the vector is zero. Mask LVTERR first to prevent this.
205 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
206 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
209 * Careful: we have to set masks only first to deassert
210 * any level-triggered sources.
212 v = apic_read(APIC_LVTT);
213 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
214 v = apic_read(APIC_LVT0);
215 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
216 v = apic_read(APIC_LVT1);
217 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
219 v = apic_read(APIC_LVTPC);
220 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
224 * Clean APIC state for other OSs:
226 apic_write(APIC_LVTT, APIC_LVT_MASKED);
227 apic_write(APIC_LVT0, APIC_LVT_MASKED);
228 apic_write(APIC_LVT1, APIC_LVT_MASKED);
230 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
232 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
233 apic_write(APIC_ESR, 0);
237 void disconnect_bsp_APIC(int virt_wire_setup)
239 /* Go back to Virtual Wire compatibility mode */
242 /* For the spurious interrupt use vector F, and enable it */
243 value = apic_read(APIC_SPIV);
244 value &= ~APIC_VECTOR_MASK;
245 value |= APIC_SPIV_APIC_ENABLED;
247 apic_write(APIC_SPIV, value);
249 if (!virt_wire_setup) {
251 * For LVT0 make it edge triggered, active high,
252 * external and enabled
254 value = apic_read(APIC_LVT0);
255 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
256 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
257 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
258 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
259 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
260 apic_write(APIC_LVT0, value);
263 apic_write(APIC_LVT0, APIC_LVT_MASKED);
266 /* For LVT1 make it edge triggered, active high, nmi and enabled */
267 value = apic_read(APIC_LVT1);
268 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
269 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
270 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
271 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
272 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
273 apic_write(APIC_LVT1, value);
276 void disable_local_APIC(void)
283 * Disable APIC (implies clearing of registers
286 value = apic_read(APIC_SPIV);
287 value &= ~APIC_SPIV_APIC_ENABLED;
288 apic_write(APIC_SPIV, value);
291 void lapic_shutdown(void)
298 local_irq_save(flags);
300 disable_local_APIC();
302 local_irq_restore(flags);
306 * This is to verify that we're looking at a real local APIC.
307 * Check these against your board if the CPUs aren't getting
308 * started for no apparent reason.
310 int __init verify_local_APIC(void)
312 unsigned int reg0, reg1;
315 * The version register is read-only in a real APIC.
317 reg0 = apic_read(APIC_LVR);
318 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
319 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
320 reg1 = apic_read(APIC_LVR);
321 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
324 * The two version reads above should print the same
325 * numbers. If the second one is different, then we
326 * poke at a non-APIC.
332 * Check if the version looks reasonably.
334 reg1 = GET_APIC_VERSION(reg0);
335 if (reg1 == 0x00 || reg1 == 0xff)
337 reg1 = lapic_get_maxlvt();
338 if (reg1 < 0x02 || reg1 == 0xff)
342 * The ID register is read/write in a real APIC.
344 reg0 = apic_read(APIC_ID);
345 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
346 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
347 reg1 = apic_read(APIC_ID);
348 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
349 apic_write(APIC_ID, reg0);
350 if (reg1 != (reg0 ^ APIC_ID_MASK))
354 * The next two are just to see if we have sane values.
355 * They're only really relevant if we're in Virtual Wire
356 * compatibility mode, but most boxes are anymore.
358 reg0 = apic_read(APIC_LVT0);
359 apic_printk(APIC_DEBUG,"Getting LVT0: %x\n", reg0);
360 reg1 = apic_read(APIC_LVT1);
361 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
366 void __init sync_Arb_IDs(void)
368 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
369 unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
370 if (ver >= 0x14) /* P4 or higher */
376 apic_wait_icr_idle();
378 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
379 apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
384 * An initial setup of the virtual wire mode.
386 void __init init_bsp_APIC(void)
391 * Don't do the setup now if we have a SMP BIOS as the
392 * through-I/O-APIC virtual wire mode might be active.
394 if (smp_found_config || !cpu_has_apic)
397 value = apic_read(APIC_LVR);
400 * Do not trust the local APIC being empty at bootup.
407 value = apic_read(APIC_SPIV);
408 value &= ~APIC_VECTOR_MASK;
409 value |= APIC_SPIV_APIC_ENABLED;
410 value |= APIC_SPIV_FOCUS_DISABLED;
411 value |= SPURIOUS_APIC_VECTOR;
412 apic_write(APIC_SPIV, value);
415 * Set up the virtual wire mode.
417 apic_write(APIC_LVT0, APIC_DM_EXTINT);
419 apic_write(APIC_LVT1, value);
422 void __cpuinit setup_local_APIC (void)
424 unsigned int value, maxlvt;
427 value = apic_read(APIC_LVR);
429 BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);
432 * Double-check whether this APIC is really registered.
433 * This is meaningless in clustered apic mode, so we skip it.
435 if (!apic_id_registered())
439 * Intel recommends to set DFR, LDR and TPR before enabling
440 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
441 * document number 292116). So here it goes...
446 * Set Task Priority to 'accept all'. We never change this
449 value = apic_read(APIC_TASKPRI);
450 value &= ~APIC_TPRI_MASK;
451 apic_write(APIC_TASKPRI, value);
454 * After a crash, we no longer service the interrupts and a pending
455 * interrupt from previous kernel might still have ISR bit set.
457 * Most probably by now CPU has serviced that pending interrupt and
458 * it might not have done the ack_APIC_irq() because it thought,
459 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
460 * does not clear the ISR bit and cpu thinks it has already serivced
461 * the interrupt. Hence a vector might get locked. It was noticed
462 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
464 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
465 value = apic_read(APIC_ISR + i*0x10);
466 for (j = 31; j >= 0; j--) {
473 * Now that we are all set up, enable the APIC
475 value = apic_read(APIC_SPIV);
476 value &= ~APIC_VECTOR_MASK;
480 value |= APIC_SPIV_APIC_ENABLED;
482 /* We always use processor focus */
485 * Set spurious IRQ vector
487 value |= SPURIOUS_APIC_VECTOR;
488 apic_write(APIC_SPIV, value);
493 * set up through-local-APIC on the BP's LINT0. This is not
494 * strictly necessary in pure symmetric-IO mode, but sometimes
495 * we delegate interrupts to the 8259A.
498 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
500 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
501 if (!smp_processor_id() && !value) {
502 value = APIC_DM_EXTINT;
503 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
506 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
507 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
510 apic_write(APIC_LVT0, value);
513 * only the BP should see the LINT1 NMI signal, obviously.
515 if (!smp_processor_id())
518 value = APIC_DM_NMI | APIC_LVT_MASKED;
519 apic_write(APIC_LVT1, value);
523 maxlvt = lapic_get_maxlvt();
524 oldvalue = apic_read(APIC_ESR);
525 value = ERROR_APIC_VECTOR; // enables sending errors
526 apic_write(APIC_LVTERR, value);
528 * spec says clear errors after enabling vector.
531 apic_write(APIC_ESR, 0);
532 value = apic_read(APIC_ESR);
533 if (value != oldvalue)
534 apic_printk(APIC_VERBOSE,
535 "ESR value after enabling vector: %08x, after %08x\n",
539 nmi_watchdog_default();
540 setup_apic_nmi_watchdog(NULL);
547 /* 'active' is true if the local APIC was enabled by us and
548 not the BIOS; this signifies that we are also responsible
549 for disabling it before entering apm/acpi suspend */
551 /* r/w apic fields */
552 unsigned int apic_id;
553 unsigned int apic_taskpri;
554 unsigned int apic_ldr;
555 unsigned int apic_dfr;
556 unsigned int apic_spiv;
557 unsigned int apic_lvtt;
558 unsigned int apic_lvtpc;
559 unsigned int apic_lvt0;
560 unsigned int apic_lvt1;
561 unsigned int apic_lvterr;
562 unsigned int apic_tmict;
563 unsigned int apic_tdcr;
564 unsigned int apic_thmr;
567 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
572 if (!apic_pm_state.active)
575 maxlvt = lapic_get_maxlvt();
577 apic_pm_state.apic_id = apic_read(APIC_ID);
578 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
579 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
580 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
581 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
582 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
584 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
585 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
586 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
587 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
588 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
589 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
590 #ifdef CONFIG_X86_MCE_INTEL
592 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
594 local_irq_save(flags);
595 disable_local_APIC();
596 local_irq_restore(flags);
600 static int lapic_resume(struct sys_device *dev)
606 if (!apic_pm_state.active)
609 maxlvt = lapic_get_maxlvt();
611 local_irq_save(flags);
612 rdmsr(MSR_IA32_APICBASE, l, h);
613 l &= ~MSR_IA32_APICBASE_BASE;
614 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
615 wrmsr(MSR_IA32_APICBASE, l, h);
616 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
617 apic_write(APIC_ID, apic_pm_state.apic_id);
618 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
619 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
620 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
621 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
622 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
623 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
624 #ifdef CONFIG_X86_MCE_INTEL
626 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
629 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
630 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
631 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
632 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
633 apic_write(APIC_ESR, 0);
635 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
636 apic_write(APIC_ESR, 0);
638 local_irq_restore(flags);
642 static struct sysdev_class lapic_sysclass = {
644 .resume = lapic_resume,
645 .suspend = lapic_suspend,
648 static struct sys_device device_lapic = {
650 .cls = &lapic_sysclass,
653 static void __cpuinit apic_pm_activate(void)
655 apic_pm_state.active = 1;
658 static int __init init_lapic_sysfs(void)
663 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
664 error = sysdev_class_register(&lapic_sysclass);
666 error = sysdev_register(&device_lapic);
669 device_initcall(init_lapic_sysfs);
671 #else /* CONFIG_PM */
673 static void apic_pm_activate(void) { }
675 #endif /* CONFIG_PM */
677 static int __init apic_set_verbosity(char *str)
680 skip_ioapic_setup = 0;
684 if (strcmp("debug", str) == 0)
685 apic_verbosity = APIC_DEBUG;
686 else if (strcmp("verbose", str) == 0)
687 apic_verbosity = APIC_VERBOSE;
689 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
690 " use apic=verbose or apic=debug\n", str);
696 early_param("apic", apic_set_verbosity);
699 * Detect and enable local APICs on non-SMP boards.
700 * Original code written by Keir Fraser.
701 * On AMD64 we trust the BIOS - if it says no APIC it is likely
702 * not correctly set up (usually the APIC timer won't work etc.)
705 static int __init detect_init_APIC (void)
708 printk(KERN_INFO "No local APIC present\n");
712 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
717 #ifdef CONFIG_X86_IO_APIC
718 static struct resource * __init ioapic_setup_resources(void)
720 #define IOAPIC_RESOURCE_NAME_SIZE 11
722 struct resource *res;
729 n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
732 mem = alloc_bootmem(n);
737 mem += sizeof(struct resource) * nr_ioapics;
739 for (i = 0; i < nr_ioapics; i++) {
741 res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
742 sprintf(mem, "IOAPIC %u", i);
743 mem += IOAPIC_RESOURCE_NAME_SIZE;
747 ioapic_resources = res;
752 static int __init ioapic_insert_resources(void)
755 struct resource *r = ioapic_resources;
758 printk("IO APIC resources could be not be allocated.\n");
762 for (i = 0; i < nr_ioapics; i++) {
763 insert_resource(&iomem_resource, r);
770 /* Insert the IO APIC resources after PCI initialization has occured to handle
771 * IO APICS that are mapped in on a BAR in PCI space. */
772 late_initcall(ioapic_insert_resources);
775 void __init init_apic_mappings(void)
777 unsigned long apic_phys;
780 * If no local APIC can be found then set up a fake all
781 * zeroes page to simulate the local APIC and another
782 * one for the IO-APIC.
784 if (!smp_found_config && detect_init_APIC()) {
785 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
786 apic_phys = __pa(apic_phys);
788 apic_phys = mp_lapic_addr;
790 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
791 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
792 APIC_BASE, apic_phys);
794 /* Put local APIC into the resource map. */
795 lapic_resource.start = apic_phys;
796 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
797 insert_resource(&iomem_resource, &lapic_resource);
800 * Fetch the APIC ID of the BSP in case we have a
801 * default configuration (or the MP table is broken).
803 boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));
806 unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
808 struct resource *ioapic_res;
810 ioapic_res = ioapic_setup_resources();
811 for (i = 0; i < nr_ioapics; i++) {
812 if (smp_found_config) {
813 ioapic_phys = mp_ioapics[i].mpc_apicaddr;
815 ioapic_phys = (unsigned long)
816 alloc_bootmem_pages(PAGE_SIZE);
817 ioapic_phys = __pa(ioapic_phys);
819 set_fixmap_nocache(idx, ioapic_phys);
820 apic_printk(APIC_VERBOSE,
821 "mapped IOAPIC to %016lx (%016lx)\n",
822 __fix_to_virt(idx), ioapic_phys);
825 if (ioapic_res != NULL) {
826 ioapic_res->start = ioapic_phys;
827 ioapic_res->end = ioapic_phys + (4 * 1024) - 1;
835 * This function sets up the local APIC timer, with a timeout of
836 * 'clocks' APIC bus clock. During calibration we actually call
837 * this function twice on the boot CPU, once with a bogus timeout
838 * value, second time for real. The other (noncalibrating) CPUs
839 * call this function only once, with the real, calibrated value.
841 * We do reads before writes even if unnecessary, to get around the
842 * P5 APIC double write bug.
845 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
847 unsigned int lvtt_value, tmp_value;
849 lvtt_value = LOCAL_TIMER_VECTOR;
851 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
853 lvtt_value |= APIC_LVT_MASKED;
855 apic_write(APIC_LVTT, lvtt_value);
860 tmp_value = apic_read(APIC_TDCR);
861 apic_write(APIC_TDCR, (tmp_value
862 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
866 apic_write(APIC_TMICT, clocks);
869 static void setup_APIC_timer(void)
871 struct clock_event_device *levt = &__get_cpu_var(lapic_events);
873 memcpy(levt, &lapic_clockevent, sizeof(*levt));
874 levt->cpumask = cpumask_of_cpu(smp_processor_id());
876 clockevents_register_device(levt);
880 * In this function we calibrate APIC bus clocks to the external
881 * timer. Unfortunately we cannot use jiffies and the timer irq
882 * to calibrate, since some later bootup code depends on getting
883 * the first irq? Ugh.
885 * We want to do the calibration only once since we
886 * want to have local timer irqs syncron. CPUs connected
887 * by the same APIC bus have the very same bus frequency.
888 * And we want to have irqs off anyways, no accidental
892 #define TICK_COUNT 100000000
894 static void __init calibrate_APIC_clock(void)
896 unsigned apic, apic_start;
897 unsigned long tsc, tsc_start;
903 * Put whatever arbitrary (but long enough) timeout
904 * value into the APIC clock, we just want to get the
905 * counter running for calibration.
907 * No interrupt enable !
909 __setup_APIC_LVTT(250000000, 0, 0);
911 apic_start = apic_read(APIC_TMCCT);
912 #ifdef CONFIG_X86_PM_TIMER
913 if (apic_calibrate_pmtmr && pmtmr_ioport) {
914 pmtimer_wait(5000); /* 5ms wait */
915 apic = apic_read(APIC_TMCCT);
916 result = (apic_start - apic) * 1000L / 5;
923 apic = apic_read(APIC_TMCCT);
925 } while ((tsc - tsc_start) < TICK_COUNT &&
926 (apic_start - apic) < TICK_COUNT);
928 result = (apic_start - apic) * 1000L * tsc_khz /
934 printk(KERN_DEBUG "APIC timer calibration result %d\n", result);
936 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
937 result / 1000 / 1000, result / 1000 % 1000);
939 /* Calculate the scaled math multiplication factor */
940 lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC, 32);
941 lapic_clockevent.max_delta_ns =
942 clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
943 lapic_clockevent.min_delta_ns =
944 clockevent_delta2ns(0xF, &lapic_clockevent);
946 calibration_result = result / HZ;
949 void __init setup_boot_APIC_clock (void)
952 * The local apic timer can be disabled via the kernel commandline.
953 * Register the lapic timer as a dummy clock event source on SMP
954 * systems, so the broadcast mechanism is used. On UP systems simply
957 if (disable_apic_timer) {
958 printk(KERN_INFO "Disabling APIC timer\n");
959 /* No broadcast on UP ! */
960 if (num_possible_cpus() > 1)
965 printk(KERN_INFO "Using local APIC timer interrupts.\n");
966 calibrate_APIC_clock();
969 * If nmi_watchdog is set to IO_APIC, we need the
970 * PIT/HPET going. Otherwise register lapic as a dummy
973 if (nmi_watchdog != NMI_IO_APIC)
974 lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
976 printk(KERN_WARNING "APIC timer registered as dummy,"
977 " due to nmi_watchdog=1!\n");
983 * AMD C1E enabled CPUs have a real nasty problem: Some BIOSes set the
984 * C1E flag only in the secondary CPU, so when we detect the wreckage
985 * we already have enabled the boot CPU local apic timer. Check, if
986 * disable_apic_timer is set and the DUMMY flag is cleared. If yes,
987 * set the DUMMY flag again and force the broadcast mode in the
990 void __cpuinit check_boot_apic_timer_broadcast(void)
992 if (!disable_apic_timer ||
993 (lapic_clockevent.features & CLOCK_EVT_FEAT_DUMMY))
996 printk(KERN_INFO "AMD C1E detected late. Force timer broadcast.\n");
997 lapic_clockevent.features |= CLOCK_EVT_FEAT_DUMMY;
1000 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE, &boot_cpu_id);
1001 local_irq_disable();
1004 void __cpuinit setup_secondary_APIC_clock(void)
1006 check_boot_apic_timer_broadcast();
1010 int setup_profiling_timer(unsigned int multiplier)
1015 void setup_APIC_extended_lvt(unsigned char lvt_off, unsigned char vector,
1016 unsigned char msg_type, unsigned char mask)
1018 unsigned long reg = (lvt_off << 4) + K8_APIC_EXT_LVT_BASE;
1019 unsigned int v = (mask << 16) | (msg_type << 8) | vector;
1024 * Local timer interrupt handler. It does both profiling and
1025 * process statistics/rescheduling.
1027 * We do profiling in every local tick, statistics/rescheduling
1028 * happen only every 'profiling multiplier' ticks. The default
1029 * multiplier is 1 and it can be changed by writing the new multiplier
1030 * value into /proc/profile.
1033 void smp_local_timer_interrupt(void)
1035 int cpu = smp_processor_id();
1036 struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
1039 * Normally we should not be here till LAPIC has been initialized but
1040 * in some cases like kdump, its possible that there is a pending LAPIC
1041 * timer interrupt from previous kernel's context and is delivered in
1042 * new kernel the moment interrupts are enabled.
1044 * Interrupts are enabled early and LAPIC is setup much later, hence
1045 * its possible that when we get here evt->event_handler is NULL.
1046 * Check for event_handler being NULL and discard the interrupt as
1049 if (!evt->event_handler) {
1051 "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
1053 lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
1058 * the NMI deadlock-detector uses this.
1060 add_pda(apic_timer_irqs, 1);
1062 evt->event_handler(evt);
1066 * Local APIC timer interrupt. This is the most natural way for doing
1067 * local interrupts, but local timer interrupts can be emulated by
1068 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1070 * [ if a single-CPU system runs an SMP kernel then we call the local
1071 * interrupt as well. Thus we cannot inline the local irq ... ]
1073 void smp_apic_timer_interrupt(struct pt_regs *regs)
1075 struct pt_regs *old_regs = set_irq_regs(regs);
1078 * NOTE! We'd better ACK the irq immediately,
1079 * because timer handling can be slow.
1083 * update_process_times() expects us to have done irq_enter().
1084 * Besides, if we don't timer interrupts ignore the global
1085 * interrupt lock, which is the WrongThing (tm) to do.
1089 smp_local_timer_interrupt();
1091 set_irq_regs(old_regs);
1095 * apic_is_clustered_box() -- Check if we can expect good TSC
1097 * Thus far, the major user of this is IBM's Summit2 series:
1099 * Clustered boxes may have unsynced TSC problems if they are
1100 * multi-chassis. Use available data to take a good guess.
1101 * If in doubt, go HPET.
1103 __cpuinit int apic_is_clustered_box(void)
1105 int i, clusters, zeros;
1107 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
1109 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
1111 for (i = 0; i < NR_CPUS; i++) {
1112 id = bios_cpu_apicid[i];
1113 if (id != BAD_APICID)
1114 __set_bit(APIC_CLUSTERID(id), clustermap);
1117 /* Problem: Partially populated chassis may not have CPUs in some of
1118 * the APIC clusters they have been allocated. Only present CPUs have
1119 * bios_cpu_apicid entries, thus causing zeroes in the bitmap. Since
1120 * clusters are allocated sequentially, count zeros only if they are
1125 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
1126 if (test_bit(i, clustermap)) {
1127 clusters += 1 + zeros;
1134 * If clusters > 2, then should be multi-chassis.
1135 * May have to revisit this when multi-core + hyperthreaded CPUs come
1136 * out, but AFAIK this will work even for them.
1138 return (clusters > 2);
1142 * This interrupt should _never_ happen with our APIC/SMP architecture
1144 asmlinkage void smp_spurious_interrupt(void)
1150 * Check if this really is a spurious interrupt and ACK it
1151 * if it is a vectored one. Just in case...
1152 * Spurious interrupts should not be ACKed.
1154 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1155 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1158 add_pda(irq_spurious_count, 1);
1163 * This interrupt should never happen with our APIC/SMP architecture
1166 asmlinkage void smp_error_interrupt(void)
1172 /* First tickle the hardware, only then report what went on. -- REW */
1173 v = apic_read(APIC_ESR);
1174 apic_write(APIC_ESR, 0);
1175 v1 = apic_read(APIC_ESR);
1177 atomic_inc(&irq_err_count);
1179 /* Here is what the APIC error bits mean:
1182 2: Send accept error
1183 3: Receive accept error
1185 5: Send illegal vector
1186 6: Received illegal vector
1187 7: Illegal register address
1189 printk (KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1190 smp_processor_id(), v , v1);
1197 * This initializes the IO-APIC and APIC hardware if this is
1200 int __init APIC_init_uniprocessor (void)
1203 printk(KERN_INFO "Apic disabled\n");
1206 if (!cpu_has_apic) {
1208 printk(KERN_INFO "Apic disabled by BIOS\n");
1212 verify_local_APIC();
1214 phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
1215 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_id));
1219 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1223 setup_boot_APIC_clock();
1224 check_nmi_watchdog();
1228 static __init int setup_disableapic(char *str)
1231 clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1234 early_param("disableapic", setup_disableapic);
1236 /* same as disableapic, for compatibility */
1237 static __init int setup_nolapic(char *str)
1239 return setup_disableapic(str);
1241 early_param("nolapic", setup_nolapic);
1243 static int __init parse_lapic_timer_c2_ok(char *arg)
1245 local_apic_timer_c2_ok = 1;
1248 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
1250 static __init int setup_noapictimer(char *str)
1252 if (str[0] != ' ' && str[0] != 0)
1254 disable_apic_timer = 1;
1257 __setup("noapictimer", setup_noapictimer);
1259 static __init int setup_apicpmtimer(char *s)
1261 apic_calibrate_pmtmr = 1;
1265 __setup("apicpmtimer", setup_apicpmtimer);