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>
38 #include <asm/proto.h>
39 #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
= 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 on a P6 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 __init
connect_bsp_APIC(void)
144 * Do not trust the local APIC being empty at bootup.
148 * PIC mode, enable APIC mode in the IMCR, i.e.
149 * connect BSP's local APIC to INT and NMI lines.
151 apic_printk(APIC_VERBOSE
, "leaving PIC mode, enabling APIC mode.\n");
157 void disconnect_bsp_APIC(int virt_wire_setup
)
161 * Put the board back into PIC mode (has an effect
162 * only on certain older boards). Note that APIC
163 * interrupts, including IPIs, won't work beyond
164 * this point! The only exception are INIT IPIs.
166 apic_printk(APIC_QUIET
, "disabling APIC mode, entering PIC mode.\n");
171 /* Go back to Virtual Wire compatibility mode */
174 /* For the spurious interrupt use vector F, and enable it */
175 value
= apic_read(APIC_SPIV
);
176 value
&= ~APIC_VECTOR_MASK
;
177 value
|= APIC_SPIV_APIC_ENABLED
;
179 apic_write(APIC_SPIV
, value
);
181 if (!virt_wire_setup
) {
182 /* For LVT0 make it edge triggered, active high, external and enabled */
183 value
= apic_read(APIC_LVT0
);
184 value
&= ~(APIC_MODE_MASK
| APIC_SEND_PENDING
|
185 APIC_INPUT_POLARITY
| APIC_LVT_REMOTE_IRR
|
186 APIC_LVT_LEVEL_TRIGGER
| APIC_LVT_MASKED
);
187 value
|= APIC_LVT_REMOTE_IRR
| APIC_SEND_PENDING
;
188 value
= SET_APIC_DELIVERY_MODE(value
, APIC_MODE_EXTINT
);
189 apic_write(APIC_LVT0
, value
);
193 apic_write(APIC_LVT0
, APIC_LVT_MASKED
);
196 /* For LVT1 make it edge triggered, active high, nmi and enabled */
197 value
= apic_read(APIC_LVT1
);
199 APIC_MODE_MASK
| APIC_SEND_PENDING
|
200 APIC_INPUT_POLARITY
| APIC_LVT_REMOTE_IRR
|
201 APIC_LVT_LEVEL_TRIGGER
| APIC_LVT_MASKED
);
202 value
|= APIC_LVT_REMOTE_IRR
| APIC_SEND_PENDING
;
203 value
= SET_APIC_DELIVERY_MODE(value
, APIC_MODE_NMI
);
204 apic_write(APIC_LVT1
, value
);
208 void disable_local_APIC(void)
215 * Disable APIC (implies clearing of registers
218 value
= apic_read(APIC_SPIV
);
219 value
&= ~APIC_SPIV_APIC_ENABLED
;
220 apic_write(APIC_SPIV
, value
);
224 * This is to verify that we're looking at a real local APIC.
225 * Check these against your board if the CPUs aren't getting
226 * started for no apparent reason.
228 int __init
verify_local_APIC(void)
230 unsigned int reg0
, reg1
;
233 * The version register is read-only in a real APIC.
235 reg0
= apic_read(APIC_LVR
);
236 apic_printk(APIC_DEBUG
, "Getting VERSION: %x\n", reg0
);
237 apic_write(APIC_LVR
, reg0
^ APIC_LVR_MASK
);
238 reg1
= apic_read(APIC_LVR
);
239 apic_printk(APIC_DEBUG
, "Getting VERSION: %x\n", reg1
);
242 * The two version reads above should print the same
243 * numbers. If the second one is different, then we
244 * poke at a non-APIC.
250 * Check if the version looks reasonably.
252 reg1
= GET_APIC_VERSION(reg0
);
253 if (reg1
== 0x00 || reg1
== 0xff)
256 if (reg1
< 0x02 || reg1
== 0xff)
260 * The ID register is read/write in a real APIC.
262 reg0
= apic_read(APIC_ID
);
263 apic_printk(APIC_DEBUG
, "Getting ID: %x\n", reg0
);
264 apic_write(APIC_ID
, reg0
^ APIC_ID_MASK
);
265 reg1
= apic_read(APIC_ID
);
266 apic_printk(APIC_DEBUG
, "Getting ID: %x\n", reg1
);
267 apic_write(APIC_ID
, reg0
);
268 if (reg1
!= (reg0
^ APIC_ID_MASK
))
272 * The next two are just to see if we have sane values.
273 * They're only really relevant if we're in Virtual Wire
274 * compatibility mode, but most boxes are anymore.
276 reg0
= apic_read(APIC_LVT0
);
277 apic_printk(APIC_DEBUG
,"Getting LVT0: %x\n", reg0
);
278 reg1
= apic_read(APIC_LVT1
);
279 apic_printk(APIC_DEBUG
, "Getting LVT1: %x\n", reg1
);
284 void __init
sync_Arb_IDs(void)
286 /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
287 unsigned int ver
= GET_APIC_VERSION(apic_read(APIC_LVR
));
288 if (ver
>= 0x14) /* P4 or higher */
294 apic_wait_icr_idle();
296 apic_printk(APIC_DEBUG
, "Synchronizing Arb IDs.\n");
297 apic_write(APIC_ICR
, APIC_DEST_ALLINC
| APIC_INT_LEVELTRIG
301 extern void __error_in_apic_c (void);
304 * An initial setup of the virtual wire mode.
306 void __init
init_bsp_APIC(void)
311 * Don't do the setup now if we have a SMP BIOS as the
312 * through-I/O-APIC virtual wire mode might be active.
314 if (smp_found_config
|| !cpu_has_apic
)
317 value
= apic_read(APIC_LVR
);
320 * Do not trust the local APIC being empty at bootup.
327 value
= apic_read(APIC_SPIV
);
328 value
&= ~APIC_VECTOR_MASK
;
329 value
|= APIC_SPIV_APIC_ENABLED
;
330 value
|= APIC_SPIV_FOCUS_DISABLED
;
331 value
|= SPURIOUS_APIC_VECTOR
;
332 apic_write(APIC_SPIV
, value
);
335 * Set up the virtual wire mode.
337 apic_write(APIC_LVT0
, APIC_DM_EXTINT
);
339 apic_write(APIC_LVT1
, value
);
342 void __cpuinit
setup_local_APIC (void)
344 unsigned int value
, maxlvt
;
346 value
= apic_read(APIC_LVR
);
348 if ((SPURIOUS_APIC_VECTOR
& 0x0f) != 0x0f)
352 * Double-check whether this APIC is really registered.
353 * This is meaningless in clustered apic mode, so we skip it.
355 if (!apic_id_registered())
359 * Intel recommends to set DFR, LDR and TPR before enabling
360 * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
361 * document number 292116). So here it goes...
366 * Set Task Priority to 'accept all'. We never change this
369 value
= apic_read(APIC_TASKPRI
);
370 value
&= ~APIC_TPRI_MASK
;
371 apic_write(APIC_TASKPRI
, value
);
374 * Now that we are all set up, enable the APIC
376 value
= apic_read(APIC_SPIV
);
377 value
&= ~APIC_VECTOR_MASK
;
381 value
|= APIC_SPIV_APIC_ENABLED
;
384 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
385 * certain networking cards. If high frequency interrupts are
386 * happening on a particular IOAPIC pin, plus the IOAPIC routing
387 * entry is masked/unmasked at a high rate as well then sooner or
388 * later IOAPIC line gets 'stuck', no more interrupts are received
389 * from the device. If focus CPU is disabled then the hang goes
392 * [ This bug can be reproduced easily with a level-triggered
393 * PCI Ne2000 networking cards and PII/PIII processors, dual
397 * Actually disabling the focus CPU check just makes the hang less
398 * frequent as it makes the interrupt distributon model be more
399 * like LRU than MRU (the short-term load is more even across CPUs).
400 * See also the comment in end_level_ioapic_irq(). --macro
403 /* Enable focus processor (bit==0) */
404 value
&= ~APIC_SPIV_FOCUS_DISABLED
;
406 /* Disable focus processor (bit==1) */
407 value
|= APIC_SPIV_FOCUS_DISABLED
;
410 * Set spurious IRQ vector
412 value
|= SPURIOUS_APIC_VECTOR
;
413 apic_write(APIC_SPIV
, value
);
418 * set up through-local-APIC on the BP's LINT0. This is not
419 * strictly necessary in pure symmetric-IO mode, but sometimes
420 * we delegate interrupts to the 8259A.
423 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
425 value
= apic_read(APIC_LVT0
) & APIC_LVT_MASKED
;
426 if (!smp_processor_id() && (pic_mode
|| !value
)) {
427 value
= APIC_DM_EXTINT
;
428 apic_printk(APIC_VERBOSE
, "enabled ExtINT on CPU#%d\n", smp_processor_id());
430 value
= APIC_DM_EXTINT
| APIC_LVT_MASKED
;
431 apic_printk(APIC_VERBOSE
, "masked ExtINT on CPU#%d\n", smp_processor_id());
433 apic_write(APIC_LVT0
, value
);
436 * only the BP should see the LINT1 NMI signal, obviously.
438 if (!smp_processor_id())
441 value
= APIC_DM_NMI
| APIC_LVT_MASKED
;
442 apic_write(APIC_LVT1
, value
);
446 maxlvt
= get_maxlvt();
447 oldvalue
= apic_read(APIC_ESR
);
448 value
= ERROR_APIC_VECTOR
; // enables sending errors
449 apic_write(APIC_LVTERR
, value
);
451 * spec says clear errors after enabling vector.
454 apic_write(APIC_ESR
, 0);
455 value
= apic_read(APIC_ESR
);
456 if (value
!= oldvalue
)
457 apic_printk(APIC_VERBOSE
,
458 "ESR value after enabling vector: %08x, after %08x\n",
462 nmi_watchdog_default();
463 if (nmi_watchdog
== NMI_LOCAL_APIC
)
464 setup_apic_nmi_watchdog();
471 /* 'active' is true if the local APIC was enabled by us and
472 not the BIOS; this signifies that we are also responsible
473 for disabling it before entering apm/acpi suspend */
475 /* r/w apic fields */
476 unsigned int apic_id
;
477 unsigned int apic_taskpri
;
478 unsigned int apic_ldr
;
479 unsigned int apic_dfr
;
480 unsigned int apic_spiv
;
481 unsigned int apic_lvtt
;
482 unsigned int apic_lvtpc
;
483 unsigned int apic_lvt0
;
484 unsigned int apic_lvt1
;
485 unsigned int apic_lvterr
;
486 unsigned int apic_tmict
;
487 unsigned int apic_tdcr
;
488 unsigned int apic_thmr
;
491 static int lapic_suspend(struct sys_device
*dev
, pm_message_t state
)
495 if (!apic_pm_state
.active
)
498 apic_pm_state
.apic_id
= apic_read(APIC_ID
);
499 apic_pm_state
.apic_taskpri
= apic_read(APIC_TASKPRI
);
500 apic_pm_state
.apic_ldr
= apic_read(APIC_LDR
);
501 apic_pm_state
.apic_dfr
= apic_read(APIC_DFR
);
502 apic_pm_state
.apic_spiv
= apic_read(APIC_SPIV
);
503 apic_pm_state
.apic_lvtt
= apic_read(APIC_LVTT
);
504 apic_pm_state
.apic_lvtpc
= apic_read(APIC_LVTPC
);
505 apic_pm_state
.apic_lvt0
= apic_read(APIC_LVT0
);
506 apic_pm_state
.apic_lvt1
= apic_read(APIC_LVT1
);
507 apic_pm_state
.apic_lvterr
= apic_read(APIC_LVTERR
);
508 apic_pm_state
.apic_tmict
= apic_read(APIC_TMICT
);
509 apic_pm_state
.apic_tdcr
= apic_read(APIC_TDCR
);
510 apic_pm_state
.apic_thmr
= apic_read(APIC_LVTTHMR
);
511 local_save_flags(flags
);
513 disable_local_APIC();
514 local_irq_restore(flags
);
518 static int lapic_resume(struct sys_device
*dev
)
523 if (!apic_pm_state
.active
)
526 local_irq_save(flags
);
527 rdmsr(MSR_IA32_APICBASE
, l
, h
);
528 l
&= ~MSR_IA32_APICBASE_BASE
;
529 l
|= MSR_IA32_APICBASE_ENABLE
| mp_lapic_addr
;
530 wrmsr(MSR_IA32_APICBASE
, l
, h
);
531 apic_write(APIC_LVTERR
, ERROR_APIC_VECTOR
| APIC_LVT_MASKED
);
532 apic_write(APIC_ID
, apic_pm_state
.apic_id
);
533 apic_write(APIC_DFR
, apic_pm_state
.apic_dfr
);
534 apic_write(APIC_LDR
, apic_pm_state
.apic_ldr
);
535 apic_write(APIC_TASKPRI
, apic_pm_state
.apic_taskpri
);
536 apic_write(APIC_SPIV
, apic_pm_state
.apic_spiv
);
537 apic_write(APIC_LVT0
, apic_pm_state
.apic_lvt0
);
538 apic_write(APIC_LVT1
, apic_pm_state
.apic_lvt1
);
539 apic_write(APIC_LVTTHMR
, apic_pm_state
.apic_thmr
);
540 apic_write(APIC_LVTPC
, apic_pm_state
.apic_lvtpc
);
541 apic_write(APIC_LVTT
, apic_pm_state
.apic_lvtt
);
542 apic_write(APIC_TDCR
, apic_pm_state
.apic_tdcr
);
543 apic_write(APIC_TMICT
, apic_pm_state
.apic_tmict
);
544 apic_write(APIC_ESR
, 0);
546 apic_write(APIC_LVTERR
, apic_pm_state
.apic_lvterr
);
547 apic_write(APIC_ESR
, 0);
549 local_irq_restore(flags
);
553 static struct sysdev_class lapic_sysclass
= {
554 set_kset_name("lapic"),
555 .resume
= lapic_resume
,
556 .suspend
= lapic_suspend
,
559 static struct sys_device device_lapic
= {
561 .cls
= &lapic_sysclass
,
564 static void __cpuinit
apic_pm_activate(void)
566 apic_pm_state
.active
= 1;
569 static int __init
init_lapic_sysfs(void)
574 /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
575 error
= sysdev_class_register(&lapic_sysclass
);
577 error
= sysdev_register(&device_lapic
);
580 device_initcall(init_lapic_sysfs
);
582 #else /* CONFIG_PM */
584 static void apic_pm_activate(void) { }
586 #endif /* CONFIG_PM */
588 static int __init
apic_set_verbosity(char *str
)
590 if (strcmp("debug", str
) == 0)
591 apic_verbosity
= APIC_DEBUG
;
592 else if (strcmp("verbose", str
) == 0)
593 apic_verbosity
= APIC_VERBOSE
;
595 printk(KERN_WARNING
"APIC Verbosity level %s not recognised"
596 " use apic=verbose or apic=debug", str
);
601 __setup("apic=", apic_set_verbosity
);
604 * Detect and enable local APICs on non-SMP boards.
605 * Original code written by Keir Fraser.
606 * On AMD64 we trust the BIOS - if it says no APIC it is likely
607 * not correctly set up (usually the APIC timer won't work etc.)
610 static int __init
detect_init_APIC (void)
613 printk(KERN_INFO
"No local APIC present\n");
617 mp_lapic_addr
= APIC_DEFAULT_PHYS_BASE
;
622 void __init
init_apic_mappings(void)
624 unsigned long apic_phys
;
627 * If no local APIC can be found then set up a fake all
628 * zeroes page to simulate the local APIC and another
629 * one for the IO-APIC.
631 if (!smp_found_config
&& detect_init_APIC()) {
632 apic_phys
= (unsigned long) alloc_bootmem_pages(PAGE_SIZE
);
633 apic_phys
= __pa(apic_phys
);
635 apic_phys
= mp_lapic_addr
;
637 set_fixmap_nocache(FIX_APIC_BASE
, apic_phys
);
638 apic_printk(APIC_VERBOSE
,"mapped APIC to %16lx (%16lx)\n", APIC_BASE
, apic_phys
);
641 * Fetch the APIC ID of the BSP in case we have a
642 * default configuration (or the MP table is broken).
644 boot_cpu_id
= GET_APIC_ID(apic_read(APIC_ID
));
646 #ifdef CONFIG_X86_IO_APIC
648 unsigned long ioapic_phys
, idx
= FIX_IO_APIC_BASE_0
;
651 for (i
= 0; i
< nr_ioapics
; i
++) {
652 if (smp_found_config
) {
653 ioapic_phys
= mp_ioapics
[i
].mpc_apicaddr
;
655 ioapic_phys
= (unsigned long) alloc_bootmem_pages(PAGE_SIZE
);
656 ioapic_phys
= __pa(ioapic_phys
);
658 set_fixmap_nocache(idx
, ioapic_phys
);
659 apic_printk(APIC_VERBOSE
,"mapped IOAPIC to %016lx (%016lx)\n",
660 __fix_to_virt(idx
), ioapic_phys
);
668 * This function sets up the local APIC timer, with a timeout of
669 * 'clocks' APIC bus clock. During calibration we actually call
670 * this function twice on the boot CPU, once with a bogus timeout
671 * value, second time for real. The other (noncalibrating) CPUs
672 * call this function only once, with the real, calibrated value.
674 * We do reads before writes even if unnecessary, to get around the
675 * P5 APIC double write bug.
678 #define APIC_DIVISOR 16
680 static void __setup_APIC_LVTT(unsigned int clocks
)
682 unsigned int lvtt_value
, tmp_value
, ver
;
683 int cpu
= smp_processor_id();
685 ver
= GET_APIC_VERSION(apic_read(APIC_LVR
));
686 lvtt_value
= APIC_LVT_TIMER_PERIODIC
| LOCAL_TIMER_VECTOR
;
688 if (cpu_isset(cpu
, timer_interrupt_broadcast_ipi_mask
))
689 lvtt_value
|= APIC_LVT_MASKED
;
691 apic_write(APIC_LVTT
, lvtt_value
);
696 tmp_value
= apic_read(APIC_TDCR
);
697 apic_write(APIC_TDCR
, (tmp_value
698 & ~(APIC_TDR_DIV_1
| APIC_TDR_DIV_TMBASE
))
701 apic_write(APIC_TMICT
, clocks
/APIC_DIVISOR
);
704 static void setup_APIC_timer(unsigned int clocks
)
708 local_irq_save(flags
);
710 /* wait for irq slice */
711 if (vxtime
.hpet_address
&& hpet_use_timer
) {
712 int trigger
= hpet_readl(HPET_T0_CMP
);
713 while (hpet_readl(HPET_COUNTER
) >= trigger
)
715 while (hpet_readl(HPET_COUNTER
) < trigger
)
721 c2
|= inb_p(0x40) << 8;
726 c2
|= inb_p(0x40) << 8;
727 } while (c2
- c1
< 300);
729 __setup_APIC_LVTT(clocks
);
730 /* Turn off PIT interrupt if we use APIC timer as main timer.
731 Only works with the PM timer right now
732 TBD fix it for HPET too. */
733 if (vxtime
.mode
== VXTIME_PMTMR
&&
734 smp_processor_id() == boot_cpu_id
&&
735 apic_runs_main_timer
== 1 &&
736 !cpu_isset(boot_cpu_id
, timer_interrupt_broadcast_ipi_mask
)) {
737 stop_timer_interrupt();
738 apic_runs_main_timer
++;
740 local_irq_restore(flags
);
744 * In this function we calibrate APIC bus clocks to the external
745 * timer. Unfortunately we cannot use jiffies and the timer irq
746 * to calibrate, since some later bootup code depends on getting
747 * the first irq? Ugh.
749 * We want to do the calibration only once since we
750 * want to have local timer irqs syncron. CPUs connected
751 * by the same APIC bus have the very same bus frequency.
752 * And we want to have irqs off anyways, no accidental
756 #define TICK_COUNT 100000000
758 static int __init
calibrate_APIC_clock(void)
760 int apic
, apic_start
, tsc
, tsc_start
;
763 * Put whatever arbitrary (but long enough) timeout
764 * value into the APIC clock, we just want to get the
765 * counter running for calibration.
767 __setup_APIC_LVTT(1000000000);
769 apic_start
= apic_read(APIC_TMCCT
);
770 #ifdef CONFIG_X86_PM_TIMER
771 if (apic_calibrate_pmtmr
&& pmtmr_ioport
) {
772 pmtimer_wait(5000); /* 5ms wait */
773 apic
= apic_read(APIC_TMCCT
);
774 result
= (apic_start
- apic
) * 1000L / 5;
781 apic
= apic_read(APIC_TMCCT
);
783 } while ((tsc
- tsc_start
) < TICK_COUNT
&&
784 (apic
- apic_start
) < TICK_COUNT
);
786 result
= (apic_start
- apic
) * 1000L * cpu_khz
/
789 printk("result %d\n", result
);
792 printk(KERN_INFO
"Detected %d.%03d MHz APIC timer.\n",
793 result
/ 1000 / 1000, result
/ 1000 % 1000);
795 return result
* APIC_DIVISOR
/ HZ
;
798 static unsigned int calibration_result
;
800 void __init
setup_boot_APIC_clock (void)
802 if (disable_apic_timer
) {
803 printk(KERN_INFO
"Disabling APIC timer\n");
807 printk(KERN_INFO
"Using local APIC timer interrupts.\n");
808 using_apic_timer
= 1;
812 calibration_result
= calibrate_APIC_clock();
814 * Now set up the timer for real.
816 setup_APIC_timer(calibration_result
);
821 void __cpuinit
setup_secondary_APIC_clock(void)
823 local_irq_disable(); /* FIXME: Do we need this? --RR */
824 setup_APIC_timer(calibration_result
);
828 void disable_APIC_timer(void)
830 if (using_apic_timer
) {
833 v
= apic_read(APIC_LVTT
);
834 apic_write(APIC_LVTT
, v
| APIC_LVT_MASKED
);
838 void enable_APIC_timer(void)
840 int cpu
= smp_processor_id();
842 if (using_apic_timer
&&
843 !cpu_isset(cpu
, timer_interrupt_broadcast_ipi_mask
)) {
846 v
= apic_read(APIC_LVTT
);
847 apic_write(APIC_LVTT
, v
& ~APIC_LVT_MASKED
);
851 void switch_APIC_timer_to_ipi(void *cpumask
)
853 cpumask_t mask
= *(cpumask_t
*)cpumask
;
854 int cpu
= smp_processor_id();
856 if (cpu_isset(cpu
, mask
) &&
857 !cpu_isset(cpu
, timer_interrupt_broadcast_ipi_mask
)) {
858 disable_APIC_timer();
859 cpu_set(cpu
, timer_interrupt_broadcast_ipi_mask
);
862 EXPORT_SYMBOL(switch_APIC_timer_to_ipi
);
864 void smp_send_timer_broadcast_ipi(void)
868 cpus_and(mask
, cpu_online_map
, timer_interrupt_broadcast_ipi_mask
);
869 if (!cpus_empty(mask
)) {
870 send_IPI_mask(mask
, LOCAL_TIMER_VECTOR
);
874 void switch_ipi_to_APIC_timer(void *cpumask
)
876 cpumask_t mask
= *(cpumask_t
*)cpumask
;
877 int cpu
= smp_processor_id();
879 if (cpu_isset(cpu
, mask
) &&
880 cpu_isset(cpu
, timer_interrupt_broadcast_ipi_mask
)) {
881 cpu_clear(cpu
, timer_interrupt_broadcast_ipi_mask
);
885 EXPORT_SYMBOL(switch_ipi_to_APIC_timer
);
887 int setup_profiling_timer(unsigned int multiplier
)
892 #ifdef CONFIG_X86_MCE_AMD
893 void setup_threshold_lvt(unsigned long lvt_off
)
896 unsigned long reg
= (lvt_off
<< 4) + 0x500;
897 v
|= THRESHOLD_APIC_VECTOR
;
900 #endif /* CONFIG_X86_MCE_AMD */
905 * Local timer interrupt handler. It does both profiling and
906 * process statistics/rescheduling.
908 * We do profiling in every local tick, statistics/rescheduling
909 * happen only every 'profiling multiplier' ticks. The default
910 * multiplier is 1 and it can be changed by writing the new multiplier
911 * value into /proc/profile.
914 void smp_local_timer_interrupt(struct pt_regs
*regs
)
916 profile_tick(CPU_PROFILING
, regs
);
918 update_process_times(user_mode(regs
));
920 if (apic_runs_main_timer
> 1 && smp_processor_id() == boot_cpu_id
)
921 main_timer_handler(regs
);
923 * We take the 'long' return path, and there every subsystem
924 * grabs the appropriate locks (kernel lock/ irq lock).
926 * we might want to decouple profiling from the 'long path',
927 * and do the profiling totally in assembly.
929 * Currently this isn't too much of an issue (performance wise),
930 * we can take more than 100K local irqs per second on a 100 MHz P5.
935 * Local APIC timer interrupt. This is the most natural way for doing
936 * local interrupts, but local timer interrupts can be emulated by
937 * broadcast interrupts too. [in case the hw doesn't support APIC timers]
939 * [ if a single-CPU system runs an SMP kernel then we call the local
940 * interrupt as well. Thus we cannot inline the local irq ... ]
942 void smp_apic_timer_interrupt(struct pt_regs
*regs
)
945 * the NMI deadlock-detector uses this.
947 add_pda(apic_timer_irqs
, 1);
950 * NOTE! We'd better ACK the irq immediately,
951 * because timer handling can be slow.
955 * update_process_times() expects us to have done irq_enter().
956 * Besides, if we don't timer interrupts ignore the global
957 * interrupt lock, which is the WrongThing (tm) to do.
961 smp_local_timer_interrupt(regs
);
966 * oem_force_hpet_timer -- force HPET mode for some boxes.
968 * Thus far, the major user of this is IBM's Summit2 series:
970 * Clustered boxes may have unsynced TSC problems if they are
971 * multi-chassis. Use available data to take a good guess.
972 * If in doubt, go HPET.
974 __cpuinit
int oem_force_hpet_timer(void)
976 int i
, clusters
, zeros
;
978 DECLARE_BITMAP(clustermap
, NUM_APIC_CLUSTERS
);
980 bitmap_zero(clustermap
, NUM_APIC_CLUSTERS
);
982 for (i
= 0; i
< NR_CPUS
; i
++) {
983 id
= bios_cpu_apicid
[i
];
984 if (id
!= BAD_APICID
)
985 __set_bit(APIC_CLUSTERID(id
), clustermap
);
988 /* Problem: Partially populated chassis may not have CPUs in some of
989 * the APIC clusters they have been allocated. Only present CPUs have
990 * bios_cpu_apicid entries, thus causing zeroes in the bitmap. Since
991 * clusters are allocated sequentially, count zeros only if they are
996 for (i
= 0; i
< NUM_APIC_CLUSTERS
; i
++) {
997 if (test_bit(i
, clustermap
)) {
998 clusters
+= 1 + zeros
;
1005 * If clusters > 2, then should be multi-chassis. Return 1 for HPET.
1006 * Else return 0 to use TSC.
1007 * May have to revisit this when multi-core + hyperthreaded CPUs come
1008 * out, but AFAIK this will work even for them.
1010 return (clusters
> 2);
1014 * This interrupt should _never_ happen with our APIC/SMP architecture
1016 asmlinkage
void smp_spurious_interrupt(void)
1022 * Check if this really is a spurious interrupt and ACK it
1023 * if it is a vectored one. Just in case...
1024 * Spurious interrupts should not be ACKed.
1026 v
= apic_read(APIC_ISR
+ ((SPURIOUS_APIC_VECTOR
& ~0x1f) >> 1));
1027 if (v
& (1 << (SPURIOUS_APIC_VECTOR
& 0x1f)))
1031 static unsigned long last_warning
;
1032 static unsigned long skipped
;
1034 /* see sw-dev-man vol 3, chapter 7.4.13.5 */
1035 if (time_before(last_warning
+30*HZ
,jiffies
)) {
1036 printk(KERN_INFO
"spurious APIC interrupt on CPU#%d, %ld skipped.\n",
1037 smp_processor_id(), skipped
);
1038 last_warning
= jiffies
;
1048 * This interrupt should never happen with our APIC/SMP architecture
1051 asmlinkage
void smp_error_interrupt(void)
1057 /* First tickle the hardware, only then report what went on. -- REW */
1058 v
= apic_read(APIC_ESR
);
1059 apic_write(APIC_ESR
, 0);
1060 v1
= apic_read(APIC_ESR
);
1062 atomic_inc(&irq_err_count
);
1064 /* Here is what the APIC error bits mean:
1067 2: Send accept error
1068 3: Receive accept error
1070 5: Send illegal vector
1071 6: Received illegal vector
1072 7: Illegal register address
1074 printk (KERN_DEBUG
"APIC error on CPU%d: %02x(%02x)\n",
1075 smp_processor_id(), v
, v1
);
1082 * This initializes the IO-APIC and APIC hardware if this is
1085 int __init
APIC_init_uniprocessor (void)
1088 printk(KERN_INFO
"Apic disabled\n");
1091 if (!cpu_has_apic
) {
1093 printk(KERN_INFO
"Apic disabled by BIOS\n");
1097 verify_local_APIC();
1101 phys_cpu_present_map
= physid_mask_of_physid(boot_cpu_id
);
1102 apic_write(APIC_ID
, SET_APIC_ID(boot_cpu_id
));
1106 #ifdef CONFIG_X86_IO_APIC
1107 if (smp_found_config
&& !skip_ioapic_setup
&& nr_ioapics
)
1112 setup_boot_APIC_clock();
1113 check_nmi_watchdog();
1117 static __init
int setup_disableapic(char *str
)
1123 static __init
int setup_nolapic(char *str
)
1129 static __init
int setup_noapictimer(char *str
)
1131 if (str
[0] != ' ' && str
[0] != 0)
1133 disable_apic_timer
= 1;
1137 static __init
int setup_apicmaintimer(char *str
)
1139 apic_runs_main_timer
= 1;
1143 __setup("apicmaintimer", setup_apicmaintimer
);
1145 static __init
int setup_noapicmaintimer(char *str
)
1147 apic_runs_main_timer
= -1;
1150 __setup("noapicmaintimer", setup_noapicmaintimer
);
1152 static __init
int setup_apicpmtimer(char *s
)
1154 apic_calibrate_pmtmr
= 1;
1156 return setup_apicmaintimer(NULL
);
1158 __setup("apicpmtimer", setup_apicpmtimer
);
1160 /* dummy parsing: see setup.c */
1162 __setup("disableapic", setup_disableapic
);
1163 __setup("nolapic", setup_nolapic
); /* same as disableapic, for compatibility */
1165 __setup("noapictimer", setup_noapictimer
);
1167 /* no "lapic" flag - we only use the lapic when the BIOS tells us so. */