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/config.h>
18 #include <linux/init.h>
21 #include <linux/delay.h>
22 #include <linux/bootmem.h>
23 #include <linux/smp_lock.h>
24 #include <linux/interrupt.h>
25 #include <linux/mc146818rtc.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/sysdev.h>
28 #include <linux/module.h>
30 #include <asm/atomic.h>
33 #include <asm/mpspec.h>
34 #include <asm/pgalloc.h>
35 #include <asm/mach_apic.h>
41 int disable_apic_timer __initdata;
44 * cpu_mask that denotes the CPUs that needs timer interrupt coming in as
45 * IPIs in place of local APIC timers
47 static cpumask_t timer_interrupt_broadcast_ipi_mask;
49 /* Using APIC to generate smp_local_timer_interrupt? */
50 int using_apic_timer = 0;
52 static void apic_pm_activate(void);
54 void enable_NMI_through_LVT0 (void * dummy)
58 v = APIC_DM_NMI; /* unmask and set to NMI */
59 apic_write(APIC_LVT0, v);
64 unsigned int v, maxlvt;
66 v = apic_read(APIC_LVR);
67 maxlvt = GET_APIC_MAXLVT(v);
71 void clear_local_APIC(void)
76 maxlvt = get_maxlvt();
79 * Masking an LVT entry on a P6 can trigger a local APIC error
80 * if the vector is zero. Mask LVTERR first to prevent this.
83 v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
84 apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
87 * Careful: we have to set masks only first to deassert
88 * any level-triggered sources.
90 v = apic_read(APIC_LVTT);
91 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
92 v = apic_read(APIC_LVT0);
93 apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
94 v = apic_read(APIC_LVT1);
95 apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
97 v = apic_read(APIC_LVTPC);
98 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
102 * Clean APIC state for other OSs:
104 apic_write(APIC_LVTT, APIC_LVT_MASKED);
105 apic_write(APIC_LVT0, APIC_LVT_MASKED);
106 apic_write(APIC_LVT1, APIC_LVT_MASKED);
108 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
110 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
111 v = GET_APIC_VERSION(apic_read(APIC_LVR));
112 apic_write(APIC_ESR, 0);
116 void __init connect_bsp_APIC(void)
120 * Do not trust the local APIC being empty at bootup.
124 * PIC mode, enable APIC mode in the IMCR, i.e.
125 * connect BSP's local APIC to INT and NMI lines.
127 apic_printk(APIC_VERBOSE, "leaving PIC mode, enabling APIC mode.\n");
133 void disconnect_bsp_APIC(int virt_wire_setup)
137 * Put the board back into PIC mode (has an effect
138 * only on certain older boards). Note that APIC
139 * interrupts, including IPIs, won't work beyond
140 * this point! The only exception are INIT IPIs.
142 apic_printk(APIC_QUIET, "disabling APIC mode, entering PIC mode.\n");
147 /* Go back to Virtual Wire compatibility mode */
150 /* For the spurious interrupt use vector F, and enable it */
151 value = apic_read(APIC_SPIV);
152 value &= ~APIC_VECTOR_MASK;
153 value |= APIC_SPIV_APIC_ENABLED;
155 apic_write(APIC_SPIV, value);
157 if (!virt_wire_setup) {
158 /* For LVT0 make it edge triggered, active high, external and enabled */
159 value = apic_read(APIC_LVT0);
160 value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
161 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
162 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
163 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
164 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
165 apic_write(APIC_LVT0, value);
169 apic_write(APIC_LVT0, APIC_LVT_MASKED);
172 /* For LVT1 make it edge triggered, active high, nmi and enabled */
173 value = apic_read(APIC_LVT1);
175 APIC_MODE_MASK | APIC_SEND_PENDING |
176 APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
177 APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
178 value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
179 value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
180 apic_write(APIC_LVT1, value);
184 void disable_local_APIC(void)
191 * Disable APIC (implies clearing of registers
194 value = apic_read(APIC_SPIV);
195 value &= ~APIC_SPIV_APIC_ENABLED;
196 apic_write(APIC_SPIV, value);
200 * This is to verify that we're looking at a real local APIC.
201 * Check these against your board if the CPUs aren't getting
202 * started for no apparent reason.
204 int __init verify_local_APIC(void)
206 unsigned int reg0, reg1;
209 * The version register is read-only in a real APIC.
211 reg0 = apic_read(APIC_LVR);
212 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
213 apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
214 reg1 = apic_read(APIC_LVR);
215 apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
218 * The two version reads above should print the same
219 * numbers. If the second one is different, then we
220 * poke at a non-APIC.
226 * Check if the version looks reasonably.
228 reg1 = GET_APIC_VERSION(reg0);
229 if (reg1 == 0x00 || reg1 == 0xff)
232 if (reg1 < 0x02 || reg1 == 0xff)
236 * The ID register is read/write in a real APIC.
238 reg0 = apic_read(APIC_ID);
239 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
240 apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
241 reg1 = apic_read(APIC_ID);
242 apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
243 apic_write(APIC_ID, reg0);
244 if (reg1 != (reg0 ^ APIC_ID_MASK))
248 * The next two are just to see if we have sane values.
249 * They're only really relevant if we're in Virtual Wire
250 * compatibility mode, but most boxes are anymore.
252 reg0 = apic_read(APIC_LVT0);
253 apic_printk(APIC_DEBUG,"Getting LVT0: %x\n", reg0);
254 reg1 = apic_read(APIC_LVT1);
255 apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
260 void __init sync_Arb_IDs(void)
262 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
263 unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
264 if (ver >= 0x14) /* P4 or higher */
270 apic_wait_icr_idle();
272 apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
273 apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
277 extern void __error_in_apic_c (void);
280 * An initial setup of the virtual wire mode.
282 void __init init_bsp_APIC(void)
287 * Don't do the setup now if we have a SMP BIOS as the
288 * through-I/O-APIC virtual wire mode might be active.
290 if (smp_found_config || !cpu_has_apic)
293 value = apic_read(APIC_LVR);
296 * Do not trust the local APIC being empty at bootup.
303 value = apic_read(APIC_SPIV);
304 value &= ~APIC_VECTOR_MASK;
305 value |= APIC_SPIV_APIC_ENABLED;
306 value |= APIC_SPIV_FOCUS_DISABLED;
307 value |= SPURIOUS_APIC_VECTOR;
308 apic_write(APIC_SPIV, value);
311 * Set up the virtual wire mode.
313 apic_write(APIC_LVT0, APIC_DM_EXTINT);
315 apic_write(APIC_LVT1, value);
318 void __cpuinit setup_local_APIC (void)
320 unsigned int value, maxlvt;
322 value = apic_read(APIC_LVR);
324 if ((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f)
328 * Double-check whether this APIC is really registered.
329 * This is meaningless in clustered apic mode, so we skip it.
331 if (!apic_id_registered())
335 * Intel recommends to set DFR, LDR and TPR before enabling
336 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
337 * document number 292116). So here it goes...
342 * Set Task Priority to 'accept all'. We never change this
345 value = apic_read(APIC_TASKPRI);
346 value &= ~APIC_TPRI_MASK;
347 apic_write(APIC_TASKPRI, value);
350 * Now that we are all set up, enable the APIC
352 value = apic_read(APIC_SPIV);
353 value &= ~APIC_VECTOR_MASK;
357 value |= APIC_SPIV_APIC_ENABLED;
360 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
361 * certain networking cards. If high frequency interrupts are
362 * happening on a particular IOAPIC pin, plus the IOAPIC routing
363 * entry is masked/unmasked at a high rate as well then sooner or
364 * later IOAPIC line gets 'stuck', no more interrupts are received
365 * from the device. If focus CPU is disabled then the hang goes
368 * [ This bug can be reproduced easily with a level-triggered
369 * PCI Ne2000 networking cards and PII/PIII processors, dual
373 * Actually disabling the focus CPU check just makes the hang less
374 * frequent as it makes the interrupt distributon model be more
375 * like LRU than MRU (the short-term load is more even across CPUs).
376 * See also the comment in end_level_ioapic_irq(). --macro
379 /* Enable focus processor (bit==0) */
380 value &= ~APIC_SPIV_FOCUS_DISABLED;
382 /* Disable focus processor (bit==1) */
383 value |= APIC_SPIV_FOCUS_DISABLED;
386 * Set spurious IRQ vector
388 value |= SPURIOUS_APIC_VECTOR;
389 apic_write(APIC_SPIV, value);
394 * set up through-local-APIC on the BP's LINT0. This is not
395 * strictly necessary in pure symmetric-IO mode, but sometimes
396 * we delegate interrupts to the 8259A.
399 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
401 value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
402 if (!smp_processor_id() && (pic_mode || !value)) {
403 value = APIC_DM_EXTINT;
404 apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", smp_processor_id());
406 value = APIC_DM_EXTINT | APIC_LVT_MASKED;
407 apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", smp_processor_id());
409 apic_write(APIC_LVT0, value);
412 * only the BP should see the LINT1 NMI signal, obviously.
414 if (!smp_processor_id())
417 value = APIC_DM_NMI | APIC_LVT_MASKED;
418 apic_write(APIC_LVT1, value);
422 maxlvt = get_maxlvt();
423 oldvalue = apic_read(APIC_ESR);
424 value = ERROR_APIC_VECTOR; // enables sending errors
425 apic_write(APIC_LVTERR, value);
427 * spec says clear errors after enabling vector.
430 apic_write(APIC_ESR, 0);
431 value = apic_read(APIC_ESR);
432 if (value != oldvalue)
433 apic_printk(APIC_VERBOSE,
434 "ESR value after enabling vector: %08x, after %08x\n",
438 nmi_watchdog_default();
439 if (nmi_watchdog == NMI_LOCAL_APIC)
440 setup_apic_nmi_watchdog();
447 /* 'active' is true if the local APIC was enabled by us and
448 not the BIOS; this signifies that we are also responsible
449 for disabling it before entering apm/acpi suspend */
451 /* r/w apic fields */
452 unsigned int apic_id;
453 unsigned int apic_taskpri;
454 unsigned int apic_ldr;
455 unsigned int apic_dfr;
456 unsigned int apic_spiv;
457 unsigned int apic_lvtt;
458 unsigned int apic_lvtpc;
459 unsigned int apic_lvt0;
460 unsigned int apic_lvt1;
461 unsigned int apic_lvterr;
462 unsigned int apic_tmict;
463 unsigned int apic_tdcr;
464 unsigned int apic_thmr;
467 static int lapic_suspend(struct sys_device *dev, pm_message_t state)
471 if (!apic_pm_state.active)
474 apic_pm_state.apic_id = apic_read(APIC_ID);
475 apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
476 apic_pm_state.apic_ldr = apic_read(APIC_LDR);
477 apic_pm_state.apic_dfr = apic_read(APIC_DFR);
478 apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
479 apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
480 apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
481 apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
482 apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
483 apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
484 apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
485 apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
486 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
487 local_save_flags(flags);
489 disable_local_APIC();
490 local_irq_restore(flags);
494 static int lapic_resume(struct sys_device *dev)
499 if (!apic_pm_state.active)
502 local_irq_save(flags);
503 rdmsr(MSR_IA32_APICBASE, l, h);
504 l &= ~MSR_IA32_APICBASE_BASE;
505 l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
506 wrmsr(MSR_IA32_APICBASE, l, h);
507 apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
508 apic_write(APIC_ID, apic_pm_state.apic_id);
509 apic_write(APIC_DFR, apic_pm_state.apic_dfr);
510 apic_write(APIC_LDR, apic_pm_state.apic_ldr);
511 apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
512 apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
513 apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
514 apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
515 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
516 apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
517 apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
518 apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
519 apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
520 apic_write(APIC_ESR, 0);
522 apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
523 apic_write(APIC_ESR, 0);
525 local_irq_restore(flags);
529 static struct sysdev_class lapic_sysclass = {
530 set_kset_name("lapic"),
531 .resume = lapic_resume,
532 .suspend = lapic_suspend,
535 static struct sys_device device_lapic = {
537 .cls = &lapic_sysclass,
540 static void __cpuinit apic_pm_activate(void)
542 apic_pm_state.active = 1;
545 static int __init init_lapic_sysfs(void)
550 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
551 error = sysdev_class_register(&lapic_sysclass);
553 error = sysdev_register(&device_lapic);
556 device_initcall(init_lapic_sysfs);
558 #else /* CONFIG_PM */
560 static void apic_pm_activate(void) { }
562 #endif /* CONFIG_PM */
564 static int __init apic_set_verbosity(char *str)
566 if (strcmp("debug", str) == 0)
567 apic_verbosity = APIC_DEBUG;
568 else if (strcmp("verbose", str) == 0)
569 apic_verbosity = APIC_VERBOSE;
571 printk(KERN_WARNING "APIC Verbosity level %s not recognised"
572 " use apic=verbose or apic=debug", str);
577 __setup("apic=", apic_set_verbosity);
580 * Detect and enable local APICs on non-SMP boards.
581 * Original code written by Keir Fraser.
582 * On AMD64 we trust the BIOS - if it says no APIC it is likely
583 * not correctly set up (usually the APIC timer won't work etc.)
586 static int __init detect_init_APIC (void)
589 printk(KERN_INFO "No local APIC present\n");
593 mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
598 void __init init_apic_mappings(void)
600 unsigned long apic_phys;
603 * If no local APIC can be found then set up a fake all
604 * zeroes page to simulate the local APIC and another
605 * one for the IO-APIC.
607 if (!smp_found_config && detect_init_APIC()) {
608 apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
609 apic_phys = __pa(apic_phys);
611 apic_phys = mp_lapic_addr;
613 set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
614 apic_printk(APIC_VERBOSE,"mapped APIC to %16lx (%16lx)\n", APIC_BASE, apic_phys);
617 * Fetch the APIC ID of the BSP in case we have a
618 * default configuration (or the MP table is broken).
620 boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));
622 #ifdef CONFIG_X86_IO_APIC
624 unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
627 for (i = 0; i < nr_ioapics; i++) {
628 if (smp_found_config) {
629 ioapic_phys = mp_ioapics[i].mpc_apicaddr;
631 ioapic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
632 ioapic_phys = __pa(ioapic_phys);
634 set_fixmap_nocache(idx, ioapic_phys);
635 apic_printk(APIC_VERBOSE,"mapped IOAPIC to %016lx (%016lx)\n",
636 __fix_to_virt(idx), ioapic_phys);
644 * This function sets up the local APIC timer, with a timeout of
645 * 'clocks' APIC bus clock. During calibration we actually call
646 * this function twice on the boot CPU, once with a bogus timeout
647 * value, second time for real. The other (noncalibrating) CPUs
648 * call this function only once, with the real, calibrated value.
650 * We do reads before writes even if unnecessary, to get around the
651 * P5 APIC double write bug.
654 #define APIC_DIVISOR 16
656 static void __setup_APIC_LVTT(unsigned int clocks)
658 unsigned int lvtt_value, tmp_value, ver;
659 int cpu = smp_processor_id();
661 ver = GET_APIC_VERSION(apic_read(APIC_LVR));
662 lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR;
664 if (cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask))
665 lvtt_value |= APIC_LVT_MASKED;
667 apic_write(APIC_LVTT, lvtt_value);
672 tmp_value = apic_read(APIC_TDCR);
673 apic_write(APIC_TDCR, (tmp_value
674 & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
677 apic_write(APIC_TMICT, clocks/APIC_DIVISOR);
680 static void setup_APIC_timer(unsigned int clocks)
684 local_irq_save(flags);
686 /* wait for irq slice */
687 if (vxtime.hpet_address) {
688 int trigger = hpet_readl(HPET_T0_CMP);
689 while (hpet_readl(HPET_COUNTER) >= trigger)
691 while (hpet_readl(HPET_COUNTER) < trigger)
697 c2 |= inb_p(0x40) << 8;
702 c2 |= inb_p(0x40) << 8;
703 } while (c2 - c1 < 300);
706 __setup_APIC_LVTT(clocks);
708 local_irq_restore(flags);
712 * In this function we calibrate APIC bus clocks to the external
713 * timer. Unfortunately we cannot use jiffies and the timer irq
714 * to calibrate, since some later bootup code depends on getting
715 * the first irq? Ugh.
717 * We want to do the calibration only once since we
718 * want to have local timer irqs syncron. CPUs connected
719 * by the same APIC bus have the very same bus frequency.
720 * And we want to have irqs off anyways, no accidental
724 #define TICK_COUNT 100000000
726 static int __init calibrate_APIC_clock(void)
728 int apic, apic_start, tsc, tsc_start;
731 * Put whatever arbitrary (but long enough) timeout
732 * value into the APIC clock, we just want to get the
733 * counter running for calibration.
735 __setup_APIC_LVTT(1000000000);
737 apic_start = apic_read(APIC_TMCCT);
741 apic = apic_read(APIC_TMCCT);
743 } while ((tsc - tsc_start) < TICK_COUNT && (apic - apic_start) < TICK_COUNT);
745 result = (apic_start - apic) * 1000L * cpu_khz / (tsc - tsc_start);
747 printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
748 result / 1000 / 1000, result / 1000 % 1000);
750 return result * APIC_DIVISOR / HZ;
753 static unsigned int calibration_result;
755 void __init setup_boot_APIC_clock (void)
757 if (disable_apic_timer) {
758 printk(KERN_INFO "Disabling APIC timer\n");
762 printk(KERN_INFO "Using local APIC timer interrupts.\n");
763 using_apic_timer = 1;
767 calibration_result = calibrate_APIC_clock();
769 * Now set up the timer for real.
771 setup_APIC_timer(calibration_result);
776 void __cpuinit setup_secondary_APIC_clock(void)
778 local_irq_disable(); /* FIXME: Do we need this? --RR */
779 setup_APIC_timer(calibration_result);
783 void disable_APIC_timer(void)
785 if (using_apic_timer) {
788 v = apic_read(APIC_LVTT);
789 apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
793 void enable_APIC_timer(void)
795 int cpu = smp_processor_id();
797 if (using_apic_timer &&
798 !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
801 v = apic_read(APIC_LVTT);
802 apic_write(APIC_LVTT, v & ~APIC_LVT_MASKED);
806 void switch_APIC_timer_to_ipi(void *cpumask)
808 cpumask_t mask = *(cpumask_t *)cpumask;
809 int cpu = smp_processor_id();
811 if (cpu_isset(cpu, mask) &&
812 !cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
813 disable_APIC_timer();
814 cpu_set(cpu, timer_interrupt_broadcast_ipi_mask);
817 EXPORT_SYMBOL(switch_APIC_timer_to_ipi);
819 void smp_send_timer_broadcast_ipi(void)
823 cpus_and(mask, cpu_online_map, timer_interrupt_broadcast_ipi_mask);
824 if (!cpus_empty(mask)) {
825 send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
829 void switch_ipi_to_APIC_timer(void *cpumask)
831 cpumask_t mask = *(cpumask_t *)cpumask;
832 int cpu = smp_processor_id();
834 if (cpu_isset(cpu, mask) &&
835 cpu_isset(cpu, timer_interrupt_broadcast_ipi_mask)) {
836 cpu_clear(cpu, timer_interrupt_broadcast_ipi_mask);
840 EXPORT_SYMBOL(switch_ipi_to_APIC_timer);
842 int setup_profiling_timer(unsigned int multiplier)
847 #ifdef CONFIG_X86_MCE_AMD
848 void setup_threshold_lvt(unsigned long lvt_off)
851 unsigned long reg = (lvt_off << 4) + 0x500;
852 v |= THRESHOLD_APIC_VECTOR;
855 #endif /* CONFIG_X86_MCE_AMD */
860 * Local timer interrupt handler. It does both profiling and
861 * process statistics/rescheduling.
863 * We do profiling in every local tick, statistics/rescheduling
864 * happen only every 'profiling multiplier' ticks. The default
865 * multiplier is 1 and it can be changed by writing the new multiplier
866 * value into /proc/profile.
869 void smp_local_timer_interrupt(struct pt_regs *regs)
871 profile_tick(CPU_PROFILING, regs);
873 update_process_times(user_mode(regs));
876 * We take the 'long' return path, and there every subsystem
877 * grabs the appropriate locks (kernel lock/ irq lock).
879 * we might want to decouple profiling from the 'long path',
880 * and do the profiling totally in assembly.
882 * Currently this isn't too much of an issue (performance wise),
883 * we can take more than 100K local irqs per second on a 100 MHz P5.
888 * Local APIC timer interrupt. This is the most natural way for doing
889 * local interrupts, but local timer interrupts can be emulated by
890 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
892 * [ if a single-CPU system runs an SMP kernel then we call the local
893 * interrupt as well. Thus we cannot inline the local irq ... ]
895 void smp_apic_timer_interrupt(struct pt_regs *regs)
898 * the NMI deadlock-detector uses this.
900 add_pda(apic_timer_irqs, 1);
903 * NOTE! We'd better ACK the irq immediately,
904 * because timer handling can be slow.
908 * update_process_times() expects us to have done irq_enter().
909 * Besides, if we don't timer interrupts ignore the global
910 * interrupt lock, which is the WrongThing (tm) to do.
914 smp_local_timer_interrupt(regs);
919 * oem_force_hpet_timer -- force HPET mode for some boxes.
921 * Thus far, the major user of this is IBM's Summit2 series:
923 * Clustered boxes may have unsynced TSC problems if they are
924 * multi-chassis. Use available data to take a good guess.
925 * If in doubt, go HPET.
927 __init int oem_force_hpet_timer(void)
929 int i, clusters, zeros;
931 DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
933 bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
935 for (i = 0; i < NR_CPUS; i++) {
936 id = bios_cpu_apicid[i];
937 if (id != BAD_APICID)
938 __set_bit(APIC_CLUSTERID(id), clustermap);
941 /* Problem: Partially populated chassis may not have CPUs in some of
942 * the APIC clusters they have been allocated. Only present CPUs have
943 * bios_cpu_apicid entries, thus causing zeroes in the bitmap. Since
944 * clusters are allocated sequentially, count zeros only if they are
949 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
950 if (test_bit(i, clustermap)) {
951 clusters += 1 + zeros;
958 * If clusters > 2, then should be multi-chassis. Return 1 for HPET.
959 * Else return 0 to use TSC.
960 * May have to revisit this when multi-core + hyperthreaded CPUs come
961 * out, but AFAIK this will work even for them.
963 return (clusters > 2);
967 * This interrupt should _never_ happen with our APIC/SMP architecture
969 asmlinkage void smp_spurious_interrupt(void)
975 * Check if this really is a spurious interrupt and ACK it
976 * if it is a vectored one. Just in case...
977 * Spurious interrupts should not be ACKed.
979 v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
980 if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
984 static unsigned long last_warning;
985 static unsigned long skipped;
987 /* see sw-dev-man vol 3, chapter 7.4.13.5 */
988 if (time_before(last_warning+30*HZ,jiffies)) {
989 printk(KERN_INFO "spurious APIC interrupt on CPU#%d, %ld skipped.\n",
990 smp_processor_id(), skipped);
991 last_warning = jiffies;
1001 * This interrupt should never happen with our APIC/SMP architecture
1004 asmlinkage void smp_error_interrupt(void)
1010 /* First tickle the hardware, only then report what went on. -- REW */
1011 v = apic_read(APIC_ESR);
1012 apic_write(APIC_ESR, 0);
1013 v1 = apic_read(APIC_ESR);
1015 atomic_inc(&irq_err_count);
1017 /* Here is what the APIC error bits mean:
1020 2: Send accept error
1021 3: Receive accept error
1023 5: Send illegal vector
1024 6: Received illegal vector
1025 7: Illegal register address
1027 printk (KERN_DEBUG "APIC error on CPU%d: %02x(%02x)\n",
1028 smp_processor_id(), v , v1);
1035 * This initializes the IO-APIC and APIC hardware if this is
1038 int __init APIC_init_uniprocessor (void)
1041 printk(KERN_INFO "Apic disabled\n");
1044 if (!cpu_has_apic) {
1046 printk(KERN_INFO "Apic disabled by BIOS\n");
1050 verify_local_APIC();
1054 phys_cpu_present_map = physid_mask_of_physid(boot_cpu_id);
1055 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_id));
1059 #ifdef CONFIG_X86_IO_APIC
1060 if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1065 setup_boot_APIC_clock();
1066 check_nmi_watchdog();
1070 static __init int setup_disableapic(char *str)
1076 static __init int setup_nolapic(char *str)
1082 static __init int setup_noapictimer(char *str)
1084 disable_apic_timer = 1;
1088 /* dummy parsing: see setup.c */
1090 __setup("disableapic", setup_disableapic);
1091 __setup("nolapic", setup_nolapic); /* same as disableapic, for compatibility */
1093 __setup("noapictimer", setup_noapictimer);
1095 /* no "lapic" flag - we only use the lapic when the BIOS tells us so. */