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/smp_lock.h>
23 #include <linux/interrupt.h>
24 #include <linux/mc146818rtc.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/sysdev.h>
27 #include <linux/module.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>
42 int apic_runs_main_timer;
43 int apic_calibrate_pmtmr __initdata;
45 int disable_apic_timer __initdata;
48 * cpu_mask that denotes the CPUs that needs timer interrupt coming in as
49 * IPIs in place of local APIC timers
51 static cpumask_t timer_interrupt_broadcast_ipi_mask;
53 /* Using APIC to generate smp_local_timer_interrupt? */
54 int using_apic_timer __read_mostly = 0;
56 static void apic_pm_activate(void);
58 void enable_NMI_through_LVT0 (void * dummy)
62 v = APIC_DM_NMI; /* unmask and set to NMI */
63 apic_write(APIC_LVT0, v);
68 unsigned int v, maxlvt;
70 v = apic_read(APIC_LVR);
71 maxlvt = GET_APIC_MAXLVT(v);
76 * 'what should we do if we get a hw irq event on an illegal vector'.
77 * each architecture has to answer this themselves.
79 void ack_bad_irq(unsigned int irq)
81 printk("unexpected IRQ trap at vector %02x\n", irq);
83 * Currently unexpected vectors happen only on SMP and APIC.
84 * We _must_ ack these because every local APIC has only N
85 * irq slots per priority level, and a 'hanging, unacked' IRQ
86 * holds up an irq slot - in excessive cases (when multiple
87 * unexpected vectors occur) that might lock up the APIC
89 * But don't ack when the APIC is disabled. -AK
95 void clear_local_APIC(void)
100 maxlvt = get_maxlvt();
103 * Masking an LVT entry can trigger a local APIC error
104 * if the vector is zero. Mask LVTERR first to prevent this.
107 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
108 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
111 * Careful: we have to set masks only first to deassert
112 * any level-triggered sources.
114 v = apic_read(APIC_LVTT);
115 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
116 v = apic_read(APIC_LVT0);
117 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
118 v = apic_read(APIC_LVT1);
119 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
121 v = apic_read(APIC_LVTPC);
122 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
126 * Clean APIC state for other OSs:
128 apic_write(APIC_LVTT, APIC_LVT_MASKED);
129 apic_write(APIC_LVT0, APIC_LVT_MASKED);
130 apic_write(APIC_LVT1, APIC_LVT_MASKED);
132 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
134 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
135 v = GET_APIC_VERSION(apic_read(APIC_LVR));
136 apic_write(APIC_ESR, 0);
140 void disconnect_bsp_APIC(int virt_wire_setup)
142 /* Go back to Virtual Wire compatibility mode */
145 /* For the spurious interrupt use vector F, and enable it */
146 value = apic_read(APIC_SPIV);
147 value &= ~APIC_VECTOR_MASK;
148 value |= APIC_SPIV_APIC_ENABLED;
150 apic_write(APIC_SPIV, value);
152 if (!virt_wire_setup) {
153 /* For LVT0 make it edge triggered, active high, external and enabled */
154 value = apic_read(APIC_LVT0);
155 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
156 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
157 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
158 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
159 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
160 apic_write(APIC_LVT0, value);
163 apic_write(APIC_LVT0, APIC_LVT_MASKED);
166 /* For LVT1 make it edge triggered, active high, nmi and enabled */
167 value = apic_read(APIC_LVT1);
168 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
169 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
170 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
171 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
172 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
173 apic_write(APIC_LVT1, value);
176 void disable_local_APIC(void)
183 * Disable APIC (implies clearing of registers
186 value = apic_read(APIC_SPIV);
187 value &= ~APIC_SPIV_APIC_ENABLED;
188 apic_write(APIC_SPIV, value);
192 * This is to verify that we're looking at a real local APIC.
193 * Check these against your board if the CPUs aren't getting
194 * started for no apparent reason.
196 int __init verify_local_APIC(void)
198 unsigned int reg0, reg1;
201 * The version register is read-only in a real APIC.
203 reg0 = apic_read(APIC_LVR);
204 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
205 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
206 reg1 = apic_read(APIC_LVR);
207 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
210 * The two version reads above should print the same
211 * numbers. If the second one is different, then we
212 * poke at a non-APIC.
218 * Check if the version looks reasonably.
220 reg1 = GET_APIC_VERSION(reg0);
221 if (reg1 == 0x00 || reg1 == 0xff)
224 if (reg1 < 0x02 || reg1 == 0xff)
228 * The ID register is read/write in a real APIC.
230 reg0 = apic_read(APIC_ID);
231 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
232 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
233 reg1 = apic_read(APIC_ID);
234 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
235 apic_write(APIC_ID, reg0);
236 if (reg1 != (reg0 ^ APIC_ID_MASK))
240 * The next two are just to see if we have sane values.
241 * They're only really relevant if we're in Virtual Wire
242 * compatibility mode, but most boxes are anymore.
244 reg0 = apic_read(APIC_LVT0);
245 apic_printk(APIC_DEBUG,"Getting LVT0: %x\n", reg0);
246 reg1 = apic_read(APIC_LVT1);
247 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
252 void __init sync_Arb_IDs(void)
254 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
255 unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
256 if (ver >= 0x14) /* P4 or higher */
262 apic_wait_icr_idle();
264 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
265 apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
270 * An initial setup of the virtual wire mode.
272 void __init init_bsp_APIC(void)
277 * Don't do the setup now if we have a SMP BIOS as the
278 * through-I/O-APIC virtual wire mode might be active.
280 if (smp_found_config || !cpu_has_apic)
283 value = apic_read(APIC_LVR);
286 * Do not trust the local APIC being empty at bootup.
293 value = apic_read(APIC_SPIV);
294 value &= ~APIC_VECTOR_MASK;
295 value |= APIC_SPIV_APIC_ENABLED;
296 value |= APIC_SPIV_FOCUS_DISABLED;
297 value |= SPURIOUS_APIC_VECTOR;
298 apic_write(APIC_SPIV, value);
301 * Set up the virtual wire mode.
303 apic_write(APIC_LVT0, APIC_DM_EXTINT);
305 apic_write(APIC_LVT1, value);
308 void __cpuinit setup_local_APIC (void)
310 unsigned int value, maxlvt;
313 value = apic_read(APIC_LVR);
315 BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);
318 * Double-check whether this APIC is really registered.
319 * This is meaningless in clustered apic mode, so we skip it.
321 if (!apic_id_registered())
325 * Intel recommends to set DFR, LDR and TPR before enabling
326 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
327 * document number 292116). So here it goes...
332 * Set Task Priority to 'accept all'. We never change this
335 value = apic_read(APIC_TASKPRI);
336 value &= ~APIC_TPRI_MASK;
337 apic_write(APIC_TASKPRI, value);
340 * After a crash, we no longer service the interrupts and a pending
341 * interrupt from previous kernel might still have ISR bit set.
343 * Most probably by now CPU has serviced that pending interrupt and
344 * it might not have done the ack_APIC_irq() because it thought,
345 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
346 * does not clear the ISR bit and cpu thinks it has already serivced
347 * the interrupt. Hence a vector might get locked. It was noticed
348 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
350 for (i = APIC_ISR_NR - 1; i >= 0; i--) {
351 value = apic_read(APIC_ISR + i*0x10);
352 for (j = 31; j >= 0; j--) {
359 * Now that we are all set up, enable the APIC
361 value = apic_read(APIC_SPIV);
362 value &= ~APIC_VECTOR_MASK;
366 value |= APIC_SPIV_APIC_ENABLED;
368 /* We always use processor focus */
371 * Set spurious IRQ vector
373 value |= SPURIOUS_APIC_VECTOR;
374 apic_write(APIC_SPIV, value);
379 * set up through-local-APIC on the BP's LINT0. This is not
380 * strictly necessary in pure symmetric-IO mode, but sometimes
381 * we delegate interrupts to the 8259A.
384 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
386 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
387 if (!smp_processor_id() && !value) {
388 value = APIC_DM_EXTINT;
389 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", smp_processor_id());
391 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
392 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", smp_processor_id());
394 apic_write(APIC_LVT0, value);
397 * only the BP should see the LINT1 NMI signal, obviously.
399 if (!smp_processor_id())
402 value = APIC_DM_NMI | APIC_LVT_MASKED;
403 apic_write(APIC_LVT1, value);
407 maxlvt = get_maxlvt();
408 oldvalue = apic_read(APIC_ESR);
409 value = ERROR_APIC_VECTOR; // enables sending errors
410 apic_write(APIC_LVTERR, value);
412 * spec says clear errors after enabling vector.
415 apic_write(APIC_ESR, 0);
416 value = apic_read(APIC_ESR);
417 if (value != oldvalue)
418 apic_printk(APIC_VERBOSE,
419 "ESR value after enabling vector: %08x, after %08x\n",
423 nmi_watchdog_default();
424 setup_apic_nmi_watchdog(NULL);
431 /* 'active' is true if the local APIC was enabled by us and
432 not the BIOS; this signifies that we are also responsible
433 for disabling it before entering apm/acpi suspend */
435 /* r/w apic fields */
436 unsigned int apic_id;
437 unsigned int apic_taskpri;
438 unsigned int apic_ldr;
439 unsigned int apic_dfr;
440 unsigned int apic_spiv;
441 unsigned int apic_lvtt;
442 unsigned int apic_lvtpc;
443 unsigned int apic_lvt0;
444 unsigned int apic_lvt1;
445 unsigned int apic_lvterr;
446 unsigned int apic_tmict;
447 unsigned int apic_tdcr;
448 unsigned int apic_thmr;
451 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
455 if (!apic_pm_state.active)
458 apic_pm_state.apic_id = apic_read(APIC_ID);
459 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
460 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
461 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
462 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
463 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
464 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
465 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
466 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
467 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
468 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
469 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
470 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
471 local_irq_save(flags);
472 disable_local_APIC();
473 local_irq_restore(flags);
477 static int lapic_resume(struct sys_device *dev)
482 if (!apic_pm_state.active)
485 local_irq_save(flags);
486 rdmsr(MSR_IA32_APICBASE, l, h);
487 l &= ~MSR_IA32_APICBASE_BASE;
488 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
489 wrmsr(MSR_IA32_APICBASE, l, h);
490 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
491 apic_write(APIC_ID, apic_pm_state.apic_id);
492 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
493 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
494 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
495 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
496 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
497 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
498 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
499 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
500 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
501 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
502 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
503 apic_write(APIC_ESR, 0);
505 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
506 apic_write(APIC_ESR, 0);
508 local_irq_restore(flags);
512 static struct sysdev_class lapic_sysclass = {
513 set_kset_name("lapic"),
514 .resume = lapic_resume,
515 .suspend = lapic_suspend,
518 static struct sys_device device_lapic = {
520 .cls = &lapic_sysclass,
523 static void __cpuinit apic_pm_activate(void)
525 apic_pm_state.active = 1;
528 static int __init init_lapic_sysfs(void)
533 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
534 error = sysdev_class_register(&lapic_sysclass);
536 error = sysdev_register(&device_lapic);
539 device_initcall(init_lapic_sysfs);
541 #else /* CONFIG_PM */
543 static void apic_pm_activate(void) { }
545 #endif /* CONFIG_PM */
547 static int __init apic_set_verbosity(char *str)
550 skip_ioapic_setup = 0;
554 if (strcmp("debug", str) == 0)
555 apic_verbosity = APIC_DEBUG;
556 else if (strcmp("verbose", str) == 0)
557 apic_verbosity = APIC_VERBOSE;
559 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
560 " use apic=verbose or apic=debug\n", str);
566 early_param("apic", apic_set_verbosity);
569 * Detect and enable local APICs on non-SMP boards.
570 * Original code written by Keir Fraser.
571 * On AMD64 we trust the BIOS - if it says no APIC it is likely
572 * not correctly set up (usually the APIC timer won't work etc.)
575 static int __init detect_init_APIC (void)
578 printk(KERN_INFO "No local APIC present\n");
582 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
587 void __init init_apic_mappings(void)
589 unsigned long apic_phys;
592 * If no local APIC can be found then set up a fake all
593 * zeroes page to simulate the local APIC and another
594 * one for the IO-APIC.
596 if (!smp_found_config && detect_init_APIC()) {
597 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
598 apic_phys = __pa(apic_phys);
600 apic_phys = mp_lapic_addr;
602 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
603 apic_printk(APIC_VERBOSE,"mapped APIC to %16lx (%16lx)\n", APIC_BASE, apic_phys);
606 * Fetch the APIC ID of the BSP in case we have a
607 * default configuration (or the MP table is broken).
609 boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));
612 unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
615 for (i = 0; i < nr_ioapics; i++) {
616 if (smp_found_config) {
617 ioapic_phys = mp_ioapics[i].mpc_apicaddr;
619 ioapic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
620 ioapic_phys = __pa(ioapic_phys);
622 set_fixmap_nocache(idx, ioapic_phys);
623 apic_printk(APIC_VERBOSE,"mapped IOAPIC to %016lx (%016lx)\n",
624 __fix_to_virt(idx), ioapic_phys);
631 * This function sets up the local APIC timer, with a timeout of
632 * 'clocks' APIC bus clock. During calibration we actually call
633 * this function twice on the boot CPU, once with a bogus timeout
634 * value, second time for real. The other (noncalibrating) CPUs
635 * call this function only once, with the real, calibrated value.
637 * We do reads before writes even if unnecessary, to get around the
638 * P5 APIC double write bug.
641 #define APIC_DIVISOR 16
643 static void __setup_APIC_LVTT(unsigned int clocks)
645 unsigned int lvtt_value, tmp_value, ver;
646 int cpu = smp_processor_id();
648 ver = GET_APIC_VERSION(apic_read(APIC_LVR));
649 lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR;
651 if (cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask))
652 lvtt_value |= APIC_LVT_MASKED;
654 apic_write(APIC_LVTT, lvtt_value);
659 tmp_value = apic_read(APIC_TDCR);
660 apic_write(APIC_TDCR, (tmp_value
661 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
664 apic_write(APIC_TMICT, clocks/APIC_DIVISOR);
667 static void setup_APIC_timer(unsigned int clocks)
671 local_irq_save(flags);
673 /* wait for irq slice */
674 if (vxtime.hpet_address && hpet_use_timer) {
675 int trigger = hpet_readl(HPET_T0_CMP);
676 while (hpet_readl(HPET_COUNTER) >= trigger)
678 while (hpet_readl(HPET_COUNTER) < trigger)
684 c2 |= inb_p(0x40) << 8;
689 c2 |= inb_p(0x40) << 8;
690 } while (c2 - c1 < 300);
692 __setup_APIC_LVTT(clocks);
693 /* Turn off PIT interrupt if we use APIC timer as main timer.
694 Only works with the PM timer right now
695 TBD fix it for HPET too. */
696 if (vxtime.mode == VXTIME_PMTMR &&
697 smp_processor_id() == boot_cpu_id &&
698 apic_runs_main_timer == 1 &&
699 !cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
700 stop_timer_interrupt();
701 apic_runs_main_timer++;
703 local_irq_restore(flags);
707 * In this function we calibrate APIC bus clocks to the external
708 * timer. Unfortunately we cannot use jiffies and the timer irq
709 * to calibrate, since some later bootup code depends on getting
710 * the first irq? Ugh.
712 * We want to do the calibration only once since we
713 * want to have local timer irqs syncron. CPUs connected
714 * by the same APIC bus have the very same bus frequency.
715 * And we want to have irqs off anyways, no accidental
719 #define TICK_COUNT 100000000
721 static int __init calibrate_APIC_clock(void)
723 int apic, apic_start, tsc, tsc_start;
726 * Put whatever arbitrary (but long enough) timeout
727 * value into the APIC clock, we just want to get the
728 * counter running for calibration.
730 __setup_APIC_LVTT(1000000000);
732 apic_start = apic_read(APIC_TMCCT);
733 #ifdef CONFIG_X86_PM_TIMER
734 if (apic_calibrate_pmtmr && pmtmr_ioport) {
735 pmtimer_wait(5000); /* 5ms wait */
736 apic = apic_read(APIC_TMCCT);
737 result = (apic_start - apic) * 1000L / 5;
744 apic = apic_read(APIC_TMCCT);
746 } while ((tsc - tsc_start) < TICK_COUNT &&
747 (apic - apic_start) < TICK_COUNT);
749 result = (apic_start - apic) * 1000L * cpu_khz /
752 printk("result %d\n", result);
755 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
756 result / 1000 / 1000, result / 1000 % 1000);
758 return result * APIC_DIVISOR / HZ;
761 static unsigned int calibration_result;
763 void __init setup_boot_APIC_clock (void)
765 if (disable_apic_timer) {
766 printk(KERN_INFO "Disabling APIC timer\n");
770 printk(KERN_INFO "Using local APIC timer interrupts.\n");
771 using_apic_timer = 1;
775 calibration_result = calibrate_APIC_clock();
777 * Now set up the timer for real.
779 setup_APIC_timer(calibration_result);
784 void __cpuinit setup_secondary_APIC_clock(void)
786 local_irq_disable(); /* FIXME: Do we need this? --RR */
787 setup_APIC_timer(calibration_result);
791 void disable_APIC_timer(void)
793 if (using_apic_timer) {
796 v = apic_read(APIC_LVTT);
798 * When an illegal vector value (0-15) is written to an LVT
799 * entry and delivery mode is Fixed, the APIC may signal an
800 * illegal vector error, with out regard to whether the mask
801 * bit is set or whether an interrupt is actually seen on input.
803 * Boot sequence might call this function when the LVTT has
804 * '0' vector value. So make sure vector field is set to
807 v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
808 apic_write(APIC_LVTT, v);
812 void enable_APIC_timer(void)
814 int cpu = smp_processor_id();
816 if (using_apic_timer &&
817 !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
820 v = apic_read(APIC_LVTT);
821 apic_write(APIC_LVTT, v & ~APIC_LVT_MASKED);
825 void switch_APIC_timer_to_ipi(void *cpumask)
827 cpumask_t mask = *(cpumask_t *)cpumask;
828 int cpu = smp_processor_id();
830 if (cpu_isset(cpu, mask) &&
831 !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
832 disable_APIC_timer();
833 cpu_set(cpu, timer_interrupt_broadcast_ipi_mask);
836 EXPORT_SYMBOL(switch_APIC_timer_to_ipi);
838 void smp_send_timer_broadcast_ipi(void)
842 cpus_and(mask, cpu_online_map, timer_interrupt_broadcast_ipi_mask);
843 if (!cpus_empty(mask)) {
844 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
848 void switch_ipi_to_APIC_timer(void *cpumask)
850 cpumask_t mask = *(cpumask_t *)cpumask;
851 int cpu = smp_processor_id();
853 if (cpu_isset(cpu, mask) &&
854 cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
855 cpu_clear(cpu, timer_interrupt_broadcast_ipi_mask);
859 EXPORT_SYMBOL(switch_ipi_to_APIC_timer);
861 int setup_profiling_timer(unsigned int multiplier)
866 void setup_APIC_extened_lvt(unsigned char lvt_off, unsigned char vector,
867 unsigned char msg_type, unsigned char mask)
869 unsigned long reg = (lvt_off << 4) + K8_APIC_EXT_LVT_BASE;
870 unsigned int v = (mask << 16) | (msg_type << 8) | vector;
877 * Local timer interrupt handler. It does both profiling and
878 * process statistics/rescheduling.
880 * We do profiling in every local tick, statistics/rescheduling
881 * happen only every 'profiling multiplier' ticks. The default
882 * multiplier is 1 and it can be changed by writing the new multiplier
883 * value into /proc/profile.
886 void smp_local_timer_interrupt(struct pt_regs *regs)
888 profile_tick(CPU_PROFILING, regs);
890 update_process_times(user_mode(regs));
892 if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
893 main_timer_handler(regs);
895 * We take the 'long' return path, and there every subsystem
896 * grabs the appropriate locks (kernel lock/ irq lock).
898 * We might want to decouple profiling from the 'long path',
899 * and do the profiling totally in assembly.
901 * Currently this isn't too much of an issue (performance wise),
902 * we can take more than 100K local irqs per second on a 100 MHz P5.
907 * Local APIC timer interrupt. This is the most natural way for doing
908 * local interrupts, but local timer interrupts can be emulated by
909 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
911 * [ if a single-CPU system runs an SMP kernel then we call the local
912 * interrupt as well. Thus we cannot inline the local irq ... ]
914 void smp_apic_timer_interrupt(struct pt_regs *regs)
917 * the NMI deadlock-detector uses this.
919 add_pda(apic_timer_irqs, 1);
922 * NOTE! We'd better ACK the irq immediately,
923 * because timer handling can be slow.
927 * update_process_times() expects us to have done irq_enter().
928 * Besides, if we don't timer interrupts ignore the global
929 * interrupt lock, which is the WrongThing (tm) to do.
933 smp_local_timer_interrupt(regs);
938 * apic_is_clustered_box() -- Check if we can expect good TSC
940 * Thus far, the major user of this is IBM's Summit2 series:
942 * Clustered boxes may have unsynced TSC problems if they are
943 * multi-chassis. Use available data to take a good guess.
944 * If in doubt, go HPET.
946 __cpuinit int apic_is_clustered_box(void)
948 int i, clusters, zeros;
950 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
952 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
954 for (i = 0; i < NR_CPUS; i++) {
955 id = bios_cpu_apicid[i];
956 if (id != BAD_APICID)
957 __set_bit(APIC_CLUSTERID(id), clustermap);
960 /* Problem: Partially populated chassis may not have CPUs in some of
961 * the APIC clusters they have been allocated. Only present CPUs have
962 * bios_cpu_apicid entries, thus causing zeroes in the bitmap. Since
963 * clusters are allocated sequentially, count zeros only if they are
968 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
969 if (test_bit(i, clustermap)) {
970 clusters += 1 + zeros;
977 * If clusters > 2, then should be multi-chassis.
978 * May have to revisit this when multi-core + hyperthreaded CPUs come
979 * out, but AFAIK this will work even for them.
981 return (clusters > 2);
985 * This interrupt should _never_ happen with our APIC/SMP architecture
987 asmlinkage void smp_spurious_interrupt(void)
993 * Check if this really is a spurious interrupt and ACK it
994 * if it is a vectored one. Just in case...
995 * Spurious interrupts should not be ACKed.
997 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
998 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1002 static unsigned long last_warning;
1003 static unsigned long skipped;
1005 /* see sw-dev-man vol 3, chapter 7.4.13.5 */
1006 if (time_before(last_warning+30*HZ,jiffies)) {
1007 printk(KERN_INFO "spurious APIC interrupt on CPU#%d, %ld skipped.\n",
1008 smp_processor_id(), skipped);
1009 last_warning = jiffies;
1019 * This interrupt should never happen with our APIC/SMP architecture
1022 asmlinkage void smp_error_interrupt(void)
1028 /* First tickle the hardware, only then report what went on. -- REW */
1029 v = apic_read(APIC_ESR);
1030 apic_write(APIC_ESR, 0);
1031 v1 = apic_read(APIC_ESR);
1033 atomic_inc(&irq_err_count);
1035 /* Here is what the APIC error bits mean:
1038 2: Send accept error
1039 3: Receive accept error
1041 5: Send illegal vector
1042 6: Received illegal vector
1043 7: Illegal register address
1045 printk (KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1046 smp_processor_id(), v , v1);
1053 * This initializes the IO-APIC and APIC hardware if this is
1056 int __init APIC_init_uniprocessor (void)
1059 printk(KERN_INFO "Apic disabled\n");
1062 if (!cpu_has_apic) {
1064 printk(KERN_INFO "Apic disabled by BIOS\n");
1068 verify_local_APIC();
1070 phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
1071 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_id));
1075 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1079 setup_boot_APIC_clock();
1080 check_nmi_watchdog();
1084 static __init int setup_disableapic(char *str)
1087 clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
1090 early_param("disableapic", setup_disableapic);
1092 /* same as disableapic, for compatibility */
1093 static __init int setup_nolapic(char *str)
1095 return setup_disableapic(str);
1097 early_param("nolapic", setup_nolapic);
1099 static __init int setup_noapictimer(char *str)
1101 if (str[0] != ' ' && str[0] != 0)
1103 disable_apic_timer = 1;
1107 static __init int setup_apicmaintimer(char *str)
1109 apic_runs_main_timer = 1;
1113 __setup("apicmaintimer", setup_apicmaintimer);
1115 static __init int setup_noapicmaintimer(char *str)
1117 apic_runs_main_timer = -1;
1120 __setup("noapicmaintimer", setup_noapicmaintimer);
1122 static __init int setup_apicpmtimer(char *s)
1124 apic_calibrate_pmtmr = 1;
1126 return setup_apicmaintimer(NULL);
1128 __setup("apicpmtimer", setup_apicpmtimer);
1130 __setup("noapictimer", setup_noapictimer);