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>
29 #include <asm/atomic.h>
32 #include <asm/mpspec.h>
33 #include <asm/pgalloc.h>
34 #include <asm/mach_apic.h>
37 #include <asm/proto.h>
38 #include <asm/timex.h>
43 int apic_runs_main_timer;
44 int apic_calibrate_pmtmr __initdata;
46 int disable_apic_timer __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;
61 * cpu_mask that denotes the CPUs that needs timer interrupt coming in as
62 * IPIs in place of local APIC timers
64 static cpumask_t timer_interrupt_broadcast_ipi_mask;
66 /* Using APIC to generate smp_local_timer_interrupt? */
67 int using_apic_timer __read_mostly = 0;
69 static void apic_pm_activate(void);
71 void apic_wait_icr_idle(void)
73 while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
77 unsigned int safe_apic_wait_icr_idle(void)
79 unsigned int send_status;
84 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
88 } while (timeout++ < 1000);
93 void enable_NMI_through_LVT0 (void * dummy)
97 /* unmask and set to NMI */
99 apic_write(APIC_LVT0, v);
104 unsigned int v, maxlvt;
106 v = apic_read(APIC_LVR);
107 maxlvt = GET_APIC_MAXLVT(v);
112 * 'what should we do if we get a hw irq event on an illegal vector'.
113 * each architecture has to answer this themselves.
115 void ack_bad_irq(unsigned int irq)
117 printk("unexpected IRQ trap at vector %02x\n", irq);
119 * Currently unexpected vectors happen only on SMP and APIC.
120 * We _must_ ack these because every local APIC has only N
121 * irq slots per priority level, and a 'hanging, unacked' IRQ
122 * holds up an irq slot - in excessive cases (when multiple
123 * unexpected vectors occur) that might lock up the APIC
125 * But don't ack when the APIC is disabled. -AK
131 void clear_local_APIC(void)
136 maxlvt = get_maxlvt();
139 * Masking an LVT entry can trigger a local APIC error
140 * if the vector is zero. Mask LVTERR first to prevent this.
143 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
144 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
147 * Careful: we have to set masks only first to deassert
148 * any level-triggered sources.
150 v = apic_read(APIC_LVTT);
151 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
152 v = apic_read(APIC_LVT0);
153 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
154 v = apic_read(APIC_LVT1);
155 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
157 v = apic_read(APIC_LVTPC);
158 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
162 * Clean APIC state for other OSs:
164 apic_write(APIC_LVTT, APIC_LVT_MASKED);
165 apic_write(APIC_LVT0, APIC_LVT_MASKED);
166 apic_write(APIC_LVT1, APIC_LVT_MASKED);
168 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
170 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
171 apic_write(APIC_ESR, 0);
175 void disconnect_bsp_APIC(int virt_wire_setup)
177 /* Go back to Virtual Wire compatibility mode */
180 /* For the spurious interrupt use vector F, and enable it */
181 value = apic_read(APIC_SPIV);
182 value &= ~APIC_VECTOR_MASK;
183 value |= APIC_SPIV_APIC_ENABLED;
185 apic_write(APIC_SPIV, value);
187 if (!virt_wire_setup) {
188 /* For LVT0 make it edge triggered, active high, external and enabled */
189 value = apic_read(APIC_LVT0);
190 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
191 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
192 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
193 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
194 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
195 apic_write(APIC_LVT0, value);
198 apic_write(APIC_LVT0, APIC_LVT_MASKED);
201 /* For LVT1 make it edge triggered, active high, nmi and enabled */
202 value = apic_read(APIC_LVT1);
203 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
204 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
205 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
206 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
207 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
208 apic_write(APIC_LVT1, value);
211 void disable_local_APIC(void)
218 * Disable APIC (implies clearing of registers
221 value = apic_read(APIC_SPIV);
222 value &= ~APIC_SPIV_APIC_ENABLED;
223 apic_write(APIC_SPIV, value);
227 * This is to verify that we're looking at a real local APIC.
228 * Check these against your board if the CPUs aren't getting
229 * started for no apparent reason.
231 int __init verify_local_APIC(void)
233 unsigned int reg0, reg1;
236 * The version register is read-only in a real APIC.
238 reg0 = apic_read(APIC_LVR);
239 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
240 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
241 reg1 = apic_read(APIC_LVR);
242 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
245 * The two version reads above should print the same
246 * numbers. If the second one is different, then we
247 * poke at a non-APIC.
253 * Check if the version looks reasonably.
255 reg1 = GET_APIC_VERSION(reg0);
256 if (reg1 == 0x00 || reg1 == 0xff)
259 if (reg1 < 0x02 || reg1 == 0xff)
263 * The ID register is read/write in a real APIC.
265 reg0 = apic_read(APIC_ID);
266 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
267 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
268 reg1 = apic_read(APIC_ID);
269 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
270 apic_write(APIC_ID, reg0);
271 if (reg1 != (reg0 ^ APIC_ID_MASK))
275 * The next two are just to see if we have sane values.
276 * They're only really relevant if we're in Virtual Wire
277 * compatibility mode, but most boxes are anymore.
279 reg0 = apic_read(APIC_LVT0);
280 apic_printk(APIC_DEBUG,"Getting LVT0: %x\n", reg0);
281 reg1 = apic_read(APIC_LVT1);
282 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
287 void __init sync_Arb_IDs(void)
289 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
290 unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
291 if (ver >= 0x14) /* P4 or higher */
297 apic_wait_icr_idle();
299 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
300 apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
305 * An initial setup of the virtual wire mode.
307 void __init init_bsp_APIC(void)
312 * Don't do the setup now if we have a SMP BIOS as the
313 * through-I/O-APIC virtual wire mode might be active.
315 if (smp_found_config || !cpu_has_apic)
318 value = apic_read(APIC_LVR);
321 * Do not trust the local APIC being empty at bootup.
328 value = apic_read(APIC_SPIV);
329 value &= ~APIC_VECTOR_MASK;
330 value |= APIC_SPIV_APIC_ENABLED;
331 value |= APIC_SPIV_FOCUS_DISABLED;
332 value |= SPURIOUS_APIC_VECTOR;
333 apic_write(APIC_SPIV, value);
336 * Set up the virtual wire mode.
338 apic_write(APIC_LVT0, APIC_DM_EXTINT);
340 apic_write(APIC_LVT1, value);
343 void __cpuinit setup_local_APIC (void)
345 unsigned int value, maxlvt;
348 value = apic_read(APIC_LVR);
350 BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);
353 * Double-check whether this APIC is really registered.
354 * This is meaningless in clustered apic mode, so we skip it.
356 if (!apic_id_registered())
360 * Intel recommends to set DFR, LDR and TPR before enabling
361 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
362 * document number 292116). So here it goes...
367 * Set Task Priority to 'accept all'. We never change this
370 value = apic_read(APIC_TASKPRI);
371 value &= ~APIC_TPRI_MASK;
372 apic_write(APIC_TASKPRI, value);
375 * After a crash, we no longer service the interrupts and a pending
376 * interrupt from previous kernel might still have ISR bit set.
378 * Most probably by now CPU has serviced that pending interrupt and
379 * it might not have done the ack_APIC_irq() because it thought,
380 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
381 * does not clear the ISR bit and cpu thinks it has already serivced
382 * the interrupt. Hence a vector might get locked. It was noticed
383 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
385 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
386 value = apic_read(APIC_ISR + i*0x10);
387 for (j = 31; j >= 0; j--) {
394 * Now that we are all set up, enable the APIC
396 value = apic_read(APIC_SPIV);
397 value &= ~APIC_VECTOR_MASK;
401 value |= APIC_SPIV_APIC_ENABLED;
403 /* We always use processor focus */
406 * Set spurious IRQ vector
408 value |= SPURIOUS_APIC_VECTOR;
409 apic_write(APIC_SPIV, value);
414 * set up through-local-APIC on the BP's LINT0. This is not
415 * strictly necessary in pure symmetric-IO mode, but sometimes
416 * we delegate interrupts to the 8259A.
419 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
421 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
422 if (!smp_processor_id() && !value) {
423 value = APIC_DM_EXTINT;
424 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", smp_processor_id());
426 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
427 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", smp_processor_id());
429 apic_write(APIC_LVT0, value);
432 * only the BP should see the LINT1 NMI signal, obviously.
434 if (!smp_processor_id())
437 value = APIC_DM_NMI | APIC_LVT_MASKED;
438 apic_write(APIC_LVT1, value);
442 maxlvt = get_maxlvt();
443 oldvalue = apic_read(APIC_ESR);
444 value = ERROR_APIC_VECTOR; // enables sending errors
445 apic_write(APIC_LVTERR, value);
447 * spec says clear errors after enabling vector.
450 apic_write(APIC_ESR, 0);
451 value = apic_read(APIC_ESR);
452 if (value != oldvalue)
453 apic_printk(APIC_VERBOSE,
454 "ESR value after enabling vector: %08x, after %08x\n",
458 nmi_watchdog_default();
459 setup_apic_nmi_watchdog(NULL);
466 /* 'active' is true if the local APIC was enabled by us and
467 not the BIOS; this signifies that we are also responsible
468 for disabling it before entering apm/acpi suspend */
470 /* r/w apic fields */
471 unsigned int apic_id;
472 unsigned int apic_taskpri;
473 unsigned int apic_ldr;
474 unsigned int apic_dfr;
475 unsigned int apic_spiv;
476 unsigned int apic_lvtt;
477 unsigned int apic_lvtpc;
478 unsigned int apic_lvt0;
479 unsigned int apic_lvt1;
480 unsigned int apic_lvterr;
481 unsigned int apic_tmict;
482 unsigned int apic_tdcr;
483 unsigned int apic_thmr;
486 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
491 if (!apic_pm_state.active)
494 maxlvt = get_maxlvt();
496 apic_pm_state.apic_id = apic_read(APIC_ID);
497 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
498 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
499 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
500 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
501 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
503 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
504 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
505 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
506 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
507 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
508 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
509 #ifdef CONFIG_X86_MCE_INTEL
511 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
513 local_irq_save(flags);
514 disable_local_APIC();
515 local_irq_restore(flags);
519 static int lapic_resume(struct sys_device *dev)
525 if (!apic_pm_state.active)
528 maxlvt = get_maxlvt();
530 local_irq_save(flags);
531 rdmsr(MSR_IA32_APICBASE, l, h);
532 l &= ~MSR_IA32_APICBASE_BASE;
533 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
534 wrmsr(MSR_IA32_APICBASE, l, h);
535 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
536 apic_write(APIC_ID, apic_pm_state.apic_id);
537 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
538 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
539 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
540 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
541 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
542 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
543 #ifdef CONFIG_X86_MCE_INTEL
545 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
548 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
549 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
550 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
551 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
552 apic_write(APIC_ESR, 0);
554 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
555 apic_write(APIC_ESR, 0);
557 local_irq_restore(flags);
561 static struct sysdev_class lapic_sysclass = {
562 set_kset_name("lapic"),
563 .resume = lapic_resume,
564 .suspend = lapic_suspend,
567 static struct sys_device device_lapic = {
569 .cls = &lapic_sysclass,
572 static void __cpuinit apic_pm_activate(void)
574 apic_pm_state.active = 1;
577 static int __init init_lapic_sysfs(void)
582 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
583 error = sysdev_class_register(&lapic_sysclass);
585 error = sysdev_register(&device_lapic);
588 device_initcall(init_lapic_sysfs);
590 #else /* CONFIG_PM */
592 static void apic_pm_activate(void) { }
594 #endif /* CONFIG_PM */
596 static int __init apic_set_verbosity(char *str)
599 skip_ioapic_setup = 0;
603 if (strcmp("debug", str) == 0)
604 apic_verbosity = APIC_DEBUG;
605 else if (strcmp("verbose", str) == 0)
606 apic_verbosity = APIC_VERBOSE;
608 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
609 " use apic=verbose or apic=debug\n", str);
615 early_param("apic", apic_set_verbosity);
618 * Detect and enable local APICs on non-SMP boards.
619 * Original code written by Keir Fraser.
620 * On AMD64 we trust the BIOS - if it says no APIC it is likely
621 * not correctly set up (usually the APIC timer won't work etc.)
624 static int __init detect_init_APIC (void)
627 printk(KERN_INFO "No local APIC present\n");
631 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
636 #ifdef CONFIG_X86_IO_APIC
637 static struct resource * __init ioapic_setup_resources(void)
639 #define IOAPIC_RESOURCE_NAME_SIZE 11
641 struct resource *res;
648 n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
651 mem = alloc_bootmem(n);
656 mem += sizeof(struct resource) * nr_ioapics;
658 for (i = 0; i < nr_ioapics; i++) {
660 res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
661 sprintf(mem, "IOAPIC %u", i);
662 mem += IOAPIC_RESOURCE_NAME_SIZE;
666 ioapic_resources = res;
671 static int __init ioapic_insert_resources(void)
674 struct resource *r = ioapic_resources;
677 printk("IO APIC resources could be not be allocated.\n");
681 for (i = 0; i < nr_ioapics; i++) {
682 insert_resource(&iomem_resource, r);
689 /* Insert the IO APIC resources after PCI initialization has occured to handle
690 * IO APICS that are mapped in on a BAR in PCI space. */
691 late_initcall(ioapic_insert_resources);
694 void __init init_apic_mappings(void)
696 unsigned long apic_phys;
699 * If no local APIC can be found then set up a fake all
700 * zeroes page to simulate the local APIC and another
701 * one for the IO-APIC.
703 if (!smp_found_config && detect_init_APIC()) {
704 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
705 apic_phys = __pa(apic_phys);
707 apic_phys = mp_lapic_addr;
709 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
710 apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
711 APIC_BASE, apic_phys);
713 /* Put local APIC into the resource map. */
714 lapic_resource.start = apic_phys;
715 lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
716 insert_resource(&iomem_resource, &lapic_resource);
719 * Fetch the APIC ID of the BSP in case we have a
720 * default configuration (or the MP table is broken).
722 boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));
725 unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
727 struct resource *ioapic_res;
729 ioapic_res = ioapic_setup_resources();
730 for (i = 0; i < nr_ioapics; i++) {
731 if (smp_found_config) {
732 ioapic_phys = mp_ioapics[i].mpc_apicaddr;
734 ioapic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
735 ioapic_phys = __pa(ioapic_phys);
737 set_fixmap_nocache(idx, ioapic_phys);
738 apic_printk(APIC_VERBOSE,"mapped IOAPIC to %016lx (%016lx)\n",
739 __fix_to_virt(idx), ioapic_phys);
742 if (ioapic_res != NULL) {
743 ioapic_res->start = ioapic_phys;
744 ioapic_res->end = ioapic_phys + (4 * 1024) - 1;
752 * This function sets up the local APIC timer, with a timeout of
753 * 'clocks' APIC bus clock. During calibration we actually call
754 * this function twice on the boot CPU, once with a bogus timeout
755 * value, second time for real. The other (noncalibrating) CPUs
756 * call this function only once, with the real, calibrated value.
758 * We do reads before writes even if unnecessary, to get around the
759 * P5 APIC double write bug.
762 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
764 unsigned int lvtt_value, tmp_value;
766 lvtt_value = LOCAL_TIMER_VECTOR;
768 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
770 lvtt_value |= APIC_LVT_MASKED;
772 apic_write(APIC_LVTT, lvtt_value);
777 tmp_value = apic_read(APIC_TDCR);
778 apic_write(APIC_TDCR, (tmp_value
779 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
783 apic_write(APIC_TMICT, clocks);
786 static void setup_APIC_timer(void)
791 local_irq_save(flags);
793 irqen = ! cpu_isset(smp_processor_id(),
794 timer_interrupt_broadcast_ipi_mask);
795 __setup_APIC_LVTT(calibration_result, 0, irqen);
796 /* Turn off PIT interrupt if we use APIC timer as main timer.
797 Only works with the PM timer right now
798 TBD fix it for HPET too. */
799 if ((pmtmr_ioport != 0) &&
800 smp_processor_id() == boot_cpu_id &&
801 apic_runs_main_timer == 1 &&
802 !cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
803 stop_timer_interrupt();
804 apic_runs_main_timer++;
806 local_irq_restore(flags);
810 * In this function we calibrate APIC bus clocks to the external
811 * timer. Unfortunately we cannot use jiffies and the timer irq
812 * to calibrate, since some later bootup code depends on getting
813 * the first irq? Ugh.
815 * We want to do the calibration only once since we
816 * want to have local timer irqs syncron. CPUs connected
817 * by the same APIC bus have the very same bus frequency.
818 * And we want to have irqs off anyways, no accidental
822 #define TICK_COUNT 100000000
824 static void __init calibrate_APIC_clock(void)
826 unsigned apic, apic_start;
827 unsigned long tsc, tsc_start;
833 * Put whatever arbitrary (but long enough) timeout
834 * value into the APIC clock, we just want to get the
835 * counter running for calibration.
837 * No interrupt enable !
839 __setup_APIC_LVTT(250000000, 0, 0);
841 apic_start = apic_read(APIC_TMCCT);
842 #ifdef CONFIG_X86_PM_TIMER
843 if (apic_calibrate_pmtmr && pmtmr_ioport) {
844 pmtimer_wait(5000); /* 5ms wait */
845 apic = apic_read(APIC_TMCCT);
846 result = (apic_start - apic) * 1000L / 5;
853 apic = apic_read(APIC_TMCCT);
855 } while ((tsc - tsc_start) < TICK_COUNT &&
856 (apic_start - apic) < TICK_COUNT);
858 result = (apic_start - apic) * 1000L * tsc_khz /
864 printk(KERN_DEBUG "APIC timer calibration result %d\n", result);
866 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
867 result / 1000 / 1000, result / 1000 % 1000);
869 calibration_result = result / HZ;
872 void __init setup_boot_APIC_clock (void)
874 if (disable_apic_timer) {
875 printk(KERN_INFO "Disabling APIC timer\n");
879 printk(KERN_INFO "Using local APIC timer interrupts.\n");
880 using_apic_timer = 1;
882 calibrate_APIC_clock();
884 * Now set up the timer for real.
889 void __cpuinit setup_secondary_APIC_clock(void)
894 void disable_APIC_timer(void)
896 if (using_apic_timer) {
899 v = apic_read(APIC_LVTT);
901 * When an illegal vector value (0-15) is written to an LVT
902 * entry and delivery mode is Fixed, the APIC may signal an
903 * illegal vector error, with out regard to whether the mask
904 * bit is set or whether an interrupt is actually seen on input.
906 * Boot sequence might call this function when the LVTT has
907 * '0' vector value. So make sure vector field is set to
910 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
911 apic_write(APIC_LVTT, v);
915 void enable_APIC_timer(void)
917 int cpu = smp_processor_id();
919 if (using_apic_timer &&
920 !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
923 v = apic_read(APIC_LVTT);
924 apic_write(APIC_LVTT, v & ~APIC_LVT_MASKED);
928 void switch_APIC_timer_to_ipi(void *cpumask)
930 cpumask_t mask = *(cpumask_t *)cpumask;
931 int cpu = smp_processor_id();
933 if (cpu_isset(cpu, mask) &&
934 !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
935 disable_APIC_timer();
936 cpu_set(cpu, timer_interrupt_broadcast_ipi_mask);
939 EXPORT_SYMBOL(switch_APIC_timer_to_ipi);
941 void smp_send_timer_broadcast_ipi(void)
943 int cpu = smp_processor_id();
946 cpus_and(mask, cpu_online_map, timer_interrupt_broadcast_ipi_mask);
948 if (cpu_isset(cpu, mask)) {
949 cpu_clear(cpu, mask);
950 add_pda(apic_timer_irqs, 1);
951 smp_local_timer_interrupt();
954 if (!cpus_empty(mask)) {
955 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
959 void switch_ipi_to_APIC_timer(void *cpumask)
961 cpumask_t mask = *(cpumask_t *)cpumask;
962 int cpu = smp_processor_id();
964 if (cpu_isset(cpu, mask) &&
965 cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
966 cpu_clear(cpu, timer_interrupt_broadcast_ipi_mask);
970 EXPORT_SYMBOL(switch_ipi_to_APIC_timer);
972 int setup_profiling_timer(unsigned int multiplier)
977 void setup_APIC_extended_lvt(unsigned char lvt_off, unsigned char vector,
978 unsigned char msg_type, unsigned char mask)
980 unsigned long reg = (lvt_off << 4) + K8_APIC_EXT_LVT_BASE;
981 unsigned int v = (mask << 16) | (msg_type << 8) | vector;
986 * Local timer interrupt handler. It does both profiling and
987 * process statistics/rescheduling.
989 * We do profiling in every local tick, statistics/rescheduling
990 * happen only every 'profiling multiplier' ticks. The default
991 * multiplier is 1 and it can be changed by writing the new multiplier
992 * value into /proc/profile.
995 void smp_local_timer_interrupt(void)
997 profile_tick(CPU_PROFILING);
999 update_process_times(user_mode(get_irq_regs()));
1001 if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
1002 main_timer_handler();
1004 * We take the 'long' return path, and there every subsystem
1005 * grabs the appropriate locks (kernel lock/ irq lock).
1007 * We might want to decouple profiling from the 'long path',
1008 * and do the profiling totally in assembly.
1010 * Currently this isn't too much of an issue (performance wise),
1011 * we can take more than 100K local irqs per second on a 100 MHz P5.
1016 * Local APIC timer interrupt. This is the most natural way for doing
1017 * local interrupts, but local timer interrupts can be emulated by
1018 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
1020 * [ if a single-CPU system runs an SMP kernel then we call the local
1021 * interrupt as well. Thus we cannot inline the local irq ... ]
1023 void smp_apic_timer_interrupt(struct pt_regs *regs)
1025 struct pt_regs *old_regs = set_irq_regs(regs);
1028 * the NMI deadlock-detector uses this.
1030 add_pda(apic_timer_irqs, 1);
1033 * NOTE! We'd better ACK the irq immediately,
1034 * because timer handling can be slow.
1038 * update_process_times() expects us to have done irq_enter().
1039 * Besides, if we don't timer interrupts ignore the global
1040 * interrupt lock, which is the WrongThing (tm) to do.
1044 smp_local_timer_interrupt();
1046 set_irq_regs(old_regs);
1050 * apic_is_clustered_box() -- Check if we can expect good TSC
1052 * Thus far, the major user of this is IBM's Summit2 series:
1054 * Clustered boxes may have unsynced TSC problems if they are
1055 * multi-chassis. Use available data to take a good guess.
1056 * If in doubt, go HPET.
1058 __cpuinit int apic_is_clustered_box(void)
1060 int i, clusters, zeros;
1062 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
1064 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
1066 for (i = 0; i < NR_CPUS; i++) {
1067 id = bios_cpu_apicid[i];
1068 if (id != BAD_APICID)
1069 __set_bit(APIC_CLUSTERID(id), clustermap);
1072 /* Problem: Partially populated chassis may not have CPUs in some of
1073 * the APIC clusters they have been allocated. Only present CPUs have
1074 * bios_cpu_apicid entries, thus causing zeroes in the bitmap. Since
1075 * clusters are allocated sequentially, count zeros only if they are
1080 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
1081 if (test_bit(i, clustermap)) {
1082 clusters += 1 + zeros;
1089 * If clusters > 2, then should be multi-chassis.
1090 * May have to revisit this when multi-core + hyperthreaded CPUs come
1091 * out, but AFAIK this will work even for them.
1093 return (clusters > 2);
1097 * This interrupt should _never_ happen with our APIC/SMP architecture
1099 asmlinkage void smp_spurious_interrupt(void)
1105 * Check if this really is a spurious interrupt and ACK it
1106 * if it is a vectored one. Just in case...
1107 * Spurious interrupts should not be ACKed.
1109 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1110 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1117 * This interrupt should never happen with our APIC/SMP architecture
1120 asmlinkage void smp_error_interrupt(void)
1126 /* First tickle the hardware, only then report what went on. -- REW */
1127 v = apic_read(APIC_ESR);
1128 apic_write(APIC_ESR, 0);
1129 v1 = apic_read(APIC_ESR);
1131 atomic_inc(&irq_err_count);
1133 /* Here is what the APIC error bits mean:
1136 2: Send accept error
1137 3: Receive accept error
1139 5: Send illegal vector
1140 6: Received illegal vector
1141 7: Illegal register address
1143 printk (KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1144 smp_processor_id(), v , v1);
1151 * This initializes the IO-APIC and APIC hardware if this is
1154 int __init APIC_init_uniprocessor (void)
1157 printk(KERN_INFO "Apic disabled\n");
1160 if (!cpu_has_apic) {
1162 printk(KERN_INFO "Apic disabled by BIOS\n");
1166 verify_local_APIC();
1168 phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
1169 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_id));
1173 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1177 setup_boot_APIC_clock();
1178 check_nmi_watchdog();
1182 static __init int setup_disableapic(char *str)
1185 clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1188 early_param("disableapic", setup_disableapic);
1190 /* same as disableapic, for compatibility */
1191 static __init int setup_nolapic(char *str)
1193 return setup_disableapic(str);
1195 early_param("nolapic", setup_nolapic);
1197 static int __init parse_lapic_timer_c2_ok(char *arg)
1199 local_apic_timer_c2_ok = 1;
1202 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
1204 static __init int setup_noapictimer(char *str)
1206 if (str[0] != ' ' && str[0] != 0)
1208 disable_apic_timer = 1;
1212 static __init int setup_apicmaintimer(char *str)
1214 apic_runs_main_timer = 1;
1218 __setup("apicmaintimer", setup_apicmaintimer);
1220 static __init int setup_noapicmaintimer(char *str)
1222 apic_runs_main_timer = -1;
1225 __setup("noapicmaintimer", setup_noapicmaintimer);
1227 static __init int setup_apicpmtimer(char *s)
1229 apic_calibrate_pmtmr = 1;
1231 return setup_apicmaintimer(NULL);
1233 __setup("apicpmtimer", setup_apicpmtimer);
1235 __setup("noapictimer", setup_noapictimer);