2
* Local APIC handling, local APIC timers
4
* (c) 1999, 2000, 2009 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/perf_event.h>
18
#include <linux/kernel_stat.h>
19
#include <linux/mc146818rtc.h>
20
#include <linux/acpi_pmtmr.h>
21
#include <linux/clockchips.h>
22
#include <linux/interrupt.h>
23
#include <linux/bootmem.h>
24
#include <linux/ftrace.h>
25
#include <linux/ioport.h>
26
#include <linux/module.h>
27
#include <linux/syscore_ops.h>
28
#include <linux/delay.h>
29
#include <linux/timex.h>
30
#include <linux/i8253.h>
31
#include <linux/dmar.h>
32
#include <linux/init.h>
33
#include <linux/cpu.h>
34
#include <linux/dmi.h>
35
#include <linux/smp.h>
38
#include <asm/perf_event.h>
39
#include <asm/x86_init.h>
40
#include <asm/pgalloc.h>
41
#include <linux/atomic.h>
42
#include <asm/mpspec.h>
43
#include <asm/i8259.h>
44
#include <asm/proto.h>
46
#include <asm/io_apic.h>
55
#include <asm/hypervisor.h>
57
unsigned int num_processors;
59
unsigned disabled_cpus __cpuinitdata;
61
/* Processor that is doing the boot up */
62
unsigned int boot_cpu_physical_apicid = -1U;
65
* The highest APIC ID seen during enumeration.
67
unsigned int max_physical_apicid;
70
* Bitmask of physically existing CPUs:
72
physid_mask_t phys_cpu_present_map;
75
* Map cpu index to physical APIC ID
77
DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
78
DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
79
EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
80
EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
85
* On x86_32, the mapping between cpu and logical apicid may vary
86
* depending on apic in use. The following early percpu variable is
87
* used for the mapping. This is where the behaviors of x86_64 and 32
88
* actually diverge. Let's keep it ugly for now.
90
DEFINE_EARLY_PER_CPU(int, x86_cpu_to_logical_apicid, BAD_APICID);
93
* Knob to control our willingness to enable the local APIC.
97
static int force_enable_local_apic __initdata;
99
* APIC command line parameters
101
static int __init parse_lapic(char *arg)
103
force_enable_local_apic = 1;
106
early_param("lapic", parse_lapic);
107
/* Local APIC was disabled by the BIOS and enabled by the kernel */
108
static int enabled_via_apicbase;
111
* Handle interrupt mode configuration register (IMCR).
112
* This register controls whether the interrupt signals
113
* that reach the BSP come from the master PIC or from the
114
* local APIC. Before entering Symmetric I/O Mode, either
115
* the BIOS or the operating system must switch out of
116
* PIC Mode by changing the IMCR.
118
static inline void imcr_pic_to_apic(void)
120
/* select IMCR register */
122
/* NMI and 8259 INTR go through APIC */
126
static inline void imcr_apic_to_pic(void)
128
/* select IMCR register */
130
/* NMI and 8259 INTR go directly to BSP */
136
static int apic_calibrate_pmtmr __initdata;
137
static __init int setup_apicpmtimer(char *s)
139
apic_calibrate_pmtmr = 1;
143
__setup("apicpmtimer", setup_apicpmtimer);
147
#ifdef CONFIG_X86_X2APIC
148
/* x2apic enabled before OS handover */
149
static int x2apic_preenabled;
150
static __init int setup_nox2apic(char *str)
152
if (x2apic_enabled()) {
153
pr_warning("Bios already enabled x2apic, "
154
"can't enforce nox2apic");
158
setup_clear_cpu_cap(X86_FEATURE_X2APIC);
161
early_param("nox2apic", setup_nox2apic);
164
unsigned long mp_lapic_addr;
166
/* Disable local APIC timer from the kernel commandline or via dmi quirk */
167
static int disable_apic_timer __initdata;
168
/* Local APIC timer works in C2 */
169
int local_apic_timer_c2_ok;
170
EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
172
int first_system_vector = 0xfe;
175
* Debug level, exported for io_apic.c
177
unsigned int apic_verbosity;
181
/* Have we found an MP table */
182
int smp_found_config;
184
static struct resource lapic_resource = {
185
.name = "Local APIC",
186
.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
189
unsigned int lapic_timer_frequency = 0;
191
static void apic_pm_activate(void);
193
static unsigned long apic_phys;
196
* Get the LAPIC version
198
static inline int lapic_get_version(void)
200
return GET_APIC_VERSION(apic_read(APIC_LVR));
204
* Check, if the APIC is integrated or a separate chip
206
static inline int lapic_is_integrated(void)
211
return APIC_INTEGRATED(lapic_get_version());
216
* Check, whether this is a modern or a first generation APIC
218
static int modern_apic(void)
220
/* AMD systems use old APIC versions, so check the CPU */
221
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
222
boot_cpu_data.x86 >= 0xf)
224
return lapic_get_version() >= 0x14;
228
* right after this call apic become NOOP driven
229
* so apic->write/read doesn't do anything
231
static void __init apic_disable(void)
233
pr_info("APIC: switched to apic NOOP\n");
237
void native_apic_wait_icr_idle(void)
239
while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
243
u32 native_safe_apic_wait_icr_idle(void)
250
send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
254
} while (timeout++ < 1000);
259
void native_apic_icr_write(u32 low, u32 id)
261
apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
262
apic_write(APIC_ICR, low);
265
u64 native_apic_icr_read(void)
269
icr2 = apic_read(APIC_ICR2);
270
icr1 = apic_read(APIC_ICR);
272
return icr1 | ((u64)icr2 << 32);
277
* get_physical_broadcast - Get number of physical broadcast IDs
279
int get_physical_broadcast(void)
281
return modern_apic() ? 0xff : 0xf;
286
* lapic_get_maxlvt - get the maximum number of local vector table entries
288
int lapic_get_maxlvt(void)
292
v = apic_read(APIC_LVR);
294
* - we always have APIC integrated on 64bit mode
295
* - 82489DXs do not report # of LVT entries
297
return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
305
#define APIC_DIVISOR 16
308
* This function sets up the local APIC timer, with a timeout of
309
* 'clocks' APIC bus clock. During calibration we actually call
310
* this function twice on the boot CPU, once with a bogus timeout
311
* value, second time for real. The other (noncalibrating) CPUs
312
* call this function only once, with the real, calibrated value.
314
* We do reads before writes even if unnecessary, to get around the
315
* P5 APIC double write bug.
317
static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
319
unsigned int lvtt_value, tmp_value;
321
lvtt_value = LOCAL_TIMER_VECTOR;
323
lvtt_value |= APIC_LVT_TIMER_PERIODIC;
324
if (!lapic_is_integrated())
325
lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
328
lvtt_value |= APIC_LVT_MASKED;
330
apic_write(APIC_LVTT, lvtt_value);
335
tmp_value = apic_read(APIC_TDCR);
336
apic_write(APIC_TDCR,
337
(tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
341
apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
345
* Setup extended LVT, AMD specific
347
* Software should use the LVT offsets the BIOS provides. The offsets
348
* are determined by the subsystems using it like those for MCE
349
* threshold or IBS. On K8 only offset 0 (APIC500) and MCE interrupts
350
* are supported. Beginning with family 10h at least 4 offsets are
353
* Since the offsets must be consistent for all cores, we keep track
354
* of the LVT offsets in software and reserve the offset for the same
355
* vector also to be used on other cores. An offset is freed by
356
* setting the entry to APIC_EILVT_MASKED.
358
* If the BIOS is right, there should be no conflicts. Otherwise a
359
* "[Firmware Bug]: ..." error message is generated. However, if
360
* software does not properly determines the offsets, it is not
361
* necessarily a BIOS bug.
364
static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
366
static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
368
return (old & APIC_EILVT_MASKED)
369
|| (new == APIC_EILVT_MASKED)
370
|| ((new & ~APIC_EILVT_MASKED) == old);
373
static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
375
unsigned int rsvd; /* 0: uninitialized */
377
if (offset >= APIC_EILVT_NR_MAX)
380
rsvd = atomic_read(&eilvt_offsets[offset]) & ~APIC_EILVT_MASKED;
383
!eilvt_entry_is_changeable(rsvd, new))
384
/* may not change if vectors are different */
386
rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
387
} while (rsvd != new);
393
* If mask=1, the LVT entry does not generate interrupts while mask=0
394
* enables the vector. See also the BKDGs. Must be called with
395
* preemption disabled.
398
int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
400
unsigned long reg = APIC_EILVTn(offset);
401
unsigned int new, old, reserved;
403
new = (mask << 16) | (msg_type << 8) | vector;
404
old = apic_read(reg);
405
reserved = reserve_eilvt_offset(offset, new);
407
if (reserved != new) {
408
pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
409
"vector 0x%x, but the register is already in use for "
410
"vector 0x%x on another cpu\n",
411
smp_processor_id(), reg, offset, new, reserved);
415
if (!eilvt_entry_is_changeable(old, new)) {
416
pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for "
417
"vector 0x%x, but the register is already in use for "
418
"vector 0x%x on this cpu\n",
419
smp_processor_id(), reg, offset, new, old);
423
apic_write(reg, new);
427
EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
430
* Program the next event, relative to now
432
static int lapic_next_event(unsigned long delta,
433
struct clock_event_device *evt)
435
apic_write(APIC_TMICT, delta);
440
* Setup the lapic timer in periodic or oneshot mode
442
static void lapic_timer_setup(enum clock_event_mode mode,
443
struct clock_event_device *evt)
448
/* Lapic used as dummy for broadcast ? */
449
if (evt->features & CLOCK_EVT_FEAT_DUMMY)
452
local_irq_save(flags);
455
case CLOCK_EVT_MODE_PERIODIC:
456
case CLOCK_EVT_MODE_ONESHOT:
457
__setup_APIC_LVTT(lapic_timer_frequency,
458
mode != CLOCK_EVT_MODE_PERIODIC, 1);
460
case CLOCK_EVT_MODE_UNUSED:
461
case CLOCK_EVT_MODE_SHUTDOWN:
462
v = apic_read(APIC_LVTT);
463
v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
464
apic_write(APIC_LVTT, v);
465
apic_write(APIC_TMICT, 0);
467
case CLOCK_EVT_MODE_RESUME:
468
/* Nothing to do here */
472
local_irq_restore(flags);
476
* Local APIC timer broadcast function
478
static void lapic_timer_broadcast(const struct cpumask *mask)
481
apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
487
* The local apic timer can be used for any function which is CPU local.
489
static struct clock_event_device lapic_clockevent = {
491
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
492
| CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
494
.set_mode = lapic_timer_setup,
495
.set_next_event = lapic_next_event,
496
.broadcast = lapic_timer_broadcast,
500
static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
503
* Setup the local APIC timer for this CPU. Copy the initialized values
504
* of the boot CPU and register the clock event in the framework.
506
static void __cpuinit setup_APIC_timer(void)
508
struct clock_event_device *levt = &__get_cpu_var(lapic_events);
510
if (this_cpu_has(X86_FEATURE_ARAT)) {
511
lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP;
512
/* Make LAPIC timer preferrable over percpu HPET */
513
lapic_clockevent.rating = 150;
516
memcpy(levt, &lapic_clockevent, sizeof(*levt));
517
levt->cpumask = cpumask_of(smp_processor_id());
519
clockevents_register_device(levt);
523
* In this functions we calibrate APIC bus clocks to the external timer.
525
* We want to do the calibration only once since we want to have local timer
526
* irqs syncron. CPUs connected by the same APIC bus have the very same bus
529
* This was previously done by reading the PIT/HPET and waiting for a wrap
530
* around to find out, that a tick has elapsed. I have a box, where the PIT
531
* readout is broken, so it never gets out of the wait loop again. This was
532
* also reported by others.
534
* Monitoring the jiffies value is inaccurate and the clockevents
535
* infrastructure allows us to do a simple substitution of the interrupt
538
* The calibration routine also uses the pm_timer when possible, as the PIT
539
* happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes
540
* back to normal later in the boot process).
543
#define LAPIC_CAL_LOOPS (HZ/10)
545
static __initdata int lapic_cal_loops = -1;
546
static __initdata long lapic_cal_t1, lapic_cal_t2;
547
static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2;
548
static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2;
549
static __initdata unsigned long lapic_cal_j1, lapic_cal_j2;
552
* Temporary interrupt handler.
554
static void __init lapic_cal_handler(struct clock_event_device *dev)
556
unsigned long long tsc = 0;
557
long tapic = apic_read(APIC_TMCCT);
558
unsigned long pm = acpi_pm_read_early();
563
switch (lapic_cal_loops++) {
565
lapic_cal_t1 = tapic;
566
lapic_cal_tsc1 = tsc;
568
lapic_cal_j1 = jiffies;
571
case LAPIC_CAL_LOOPS:
572
lapic_cal_t2 = tapic;
573
lapic_cal_tsc2 = tsc;
574
if (pm < lapic_cal_pm1)
575
pm += ACPI_PM_OVRRUN;
577
lapic_cal_j2 = jiffies;
583
calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc)
585
const long pm_100ms = PMTMR_TICKS_PER_SEC / 10;
586
const long pm_thresh = pm_100ms / 100;
590
#ifndef CONFIG_X86_PM_TIMER
594
apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm);
596
/* Check, if the PM timer is available */
600
mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22);
602
if (deltapm > (pm_100ms - pm_thresh) &&
603
deltapm < (pm_100ms + pm_thresh)) {
604
apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n");
608
res = (((u64)deltapm) * mult) >> 22;
609
do_div(res, 1000000);
610
pr_warning("APIC calibration not consistent "
611
"with PM-Timer: %ldms instead of 100ms\n",(long)res);
613
/* Correct the lapic counter value */
614
res = (((u64)(*delta)) * pm_100ms);
615
do_div(res, deltapm);
616
pr_info("APIC delta adjusted to PM-Timer: "
617
"%lu (%ld)\n", (unsigned long)res, *delta);
620
/* Correct the tsc counter value */
622
res = (((u64)(*deltatsc)) * pm_100ms);
623
do_div(res, deltapm);
624
apic_printk(APIC_VERBOSE, "TSC delta adjusted to "
625
"PM-Timer: %lu (%ld)\n",
626
(unsigned long)res, *deltatsc);
627
*deltatsc = (long)res;
633
static int __init calibrate_APIC_clock(void)
635
struct clock_event_device *levt = &__get_cpu_var(lapic_events);
636
void (*real_handler)(struct clock_event_device *dev);
637
unsigned long deltaj;
638
long delta, deltatsc;
639
int pm_referenced = 0;
642
* check if lapic timer has already been calibrated by platform
643
* specific routine, such as tsc calibration code. if so, we just fill
644
* in the clockevent structure and return.
647
if (lapic_timer_frequency) {
648
apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
649
lapic_timer_frequency);
650
lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR,
651
TICK_NSEC, lapic_clockevent.shift);
652
lapic_clockevent.max_delta_ns =
653
clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
654
lapic_clockevent.min_delta_ns =
655
clockevent_delta2ns(0xF, &lapic_clockevent);
656
lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
662
/* Replace the global interrupt handler */
663
real_handler = global_clock_event->event_handler;
664
global_clock_event->event_handler = lapic_cal_handler;
667
* Setup the APIC counter to maximum. There is no way the lapic
668
* can underflow in the 100ms detection time frame
670
__setup_APIC_LVTT(0xffffffff, 0, 0);
672
/* Let the interrupts run */
675
while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
680
/* Restore the real event handler */
681
global_clock_event->event_handler = real_handler;
683
/* Build delta t1-t2 as apic timer counts down */
684
delta = lapic_cal_t1 - lapic_cal_t2;
685
apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta);
687
deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1);
689
/* we trust the PM based calibration if possible */
690
pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1,
693
/* Calculate the scaled math multiplication factor */
694
lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS,
695
lapic_clockevent.shift);
696
lapic_clockevent.max_delta_ns =
697
clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent);
698
lapic_clockevent.min_delta_ns =
699
clockevent_delta2ns(0xF, &lapic_clockevent);
701
lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
703
apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta);
704
apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult);
705
apic_printk(APIC_VERBOSE, "..... calibration result: %u\n",
706
lapic_timer_frequency);
709
apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
711
(deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
712
(deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
715
apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
717
lapic_timer_frequency / (1000000 / HZ),
718
lapic_timer_frequency % (1000000 / HZ));
721
* Do a sanity check on the APIC calibration result
723
if (lapic_timer_frequency < (1000000 / HZ)) {
725
pr_warning("APIC frequency too slow, disabling apic timer\n");
729
levt->features &= ~CLOCK_EVT_FEAT_DUMMY;
732
* PM timer calibration failed or not turned on
733
* so lets try APIC timer based calibration
735
if (!pm_referenced) {
736
apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
739
* Setup the apic timer manually
741
levt->event_handler = lapic_cal_handler;
742
lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
743
lapic_cal_loops = -1;
745
/* Let the interrupts run */
748
while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
751
/* Stop the lapic timer */
752
lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
755
deltaj = lapic_cal_j2 - lapic_cal_j1;
756
apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
758
/* Check, if the jiffies result is consistent */
759
if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
760
apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
762
levt->features |= CLOCK_EVT_FEAT_DUMMY;
766
if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
767
pr_warning("APIC timer disabled due to verification failure\n");
775
* Setup the boot APIC
777
* Calibrate and verify the result.
779
void __init setup_boot_APIC_clock(void)
782
* The local apic timer can be disabled via the kernel
783
* commandline or from the CPU detection code. Register the lapic
784
* timer as a dummy clock event source on SMP systems, so the
785
* broadcast mechanism is used. On UP systems simply ignore it.
787
if (disable_apic_timer) {
788
pr_info("Disabling APIC timer\n");
789
/* No broadcast on UP ! */
790
if (num_possible_cpus() > 1) {
791
lapic_clockevent.mult = 1;
797
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
798
"calibrating APIC timer ...\n");
800
if (calibrate_APIC_clock()) {
801
/* No broadcast on UP ! */
802
if (num_possible_cpus() > 1)
808
* If nmi_watchdog is set to IO_APIC, we need the
809
* PIT/HPET going. Otherwise register lapic as a dummy
812
lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
814
/* Setup the lapic or request the broadcast */
818
void __cpuinit setup_secondary_APIC_clock(void)
824
* The guts of the apic timer interrupt
826
static void local_apic_timer_interrupt(void)
828
int cpu = smp_processor_id();
829
struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
832
* Normally we should not be here till LAPIC has been initialized but
833
* in some cases like kdump, its possible that there is a pending LAPIC
834
* timer interrupt from previous kernel's context and is delivered in
835
* new kernel the moment interrupts are enabled.
837
* Interrupts are enabled early and LAPIC is setup much later, hence
838
* its possible that when we get here evt->event_handler is NULL.
839
* Check for event_handler being NULL and discard the interrupt as
842
if (!evt->event_handler) {
843
pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
845
lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
850
* the NMI deadlock-detector uses this.
852
inc_irq_stat(apic_timer_irqs);
854
evt->event_handler(evt);
858
* Local APIC timer interrupt. This is the most natural way for doing
859
* local interrupts, but local timer interrupts can be emulated by
860
* broadcast interrupts too. [in case the hw doesn't support APIC timers]
862
* [ if a single-CPU system runs an SMP kernel then we call the local
863
* interrupt as well. Thus we cannot inline the local irq ... ]
865
void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
867
struct pt_regs *old_regs = set_irq_regs(regs);
870
* NOTE! We'd better ACK the irq immediately,
871
* because timer handling can be slow.
875
* update_process_times() expects us to have done irq_enter().
876
* Besides, if we don't timer interrupts ignore the global
877
* interrupt lock, which is the WrongThing (tm) to do.
881
local_apic_timer_interrupt();
884
set_irq_regs(old_regs);
887
int setup_profiling_timer(unsigned int multiplier)
893
* Local APIC start and shutdown
897
* clear_local_APIC - shutdown the local APIC
899
* This is called, when a CPU is disabled and before rebooting, so the state of
900
* the local APIC has no dangling leftovers. Also used to cleanout any BIOS
901
* leftovers during boot.
903
void clear_local_APIC(void)
908
/* APIC hasn't been mapped yet */
909
if (!x2apic_mode && !apic_phys)
912
maxlvt = lapic_get_maxlvt();
914
* Masking an LVT entry can trigger a local APIC error
915
* if the vector is zero. Mask LVTERR first to prevent this.
918
v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
919
apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
922
* Careful: we have to set masks only first to deassert
923
* any level-triggered sources.
925
v = apic_read(APIC_LVTT);
926
apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
927
v = apic_read(APIC_LVT0);
928
apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
929
v = apic_read(APIC_LVT1);
930
apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
932
v = apic_read(APIC_LVTPC);
933
apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
936
/* lets not touch this if we didn't frob it */
937
#ifdef CONFIG_X86_THERMAL_VECTOR
939
v = apic_read(APIC_LVTTHMR);
940
apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
943
#ifdef CONFIG_X86_MCE_INTEL
945
v = apic_read(APIC_LVTCMCI);
946
if (!(v & APIC_LVT_MASKED))
947
apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED);
952
* Clean APIC state for other OSs:
954
apic_write(APIC_LVTT, APIC_LVT_MASKED);
955
apic_write(APIC_LVT0, APIC_LVT_MASKED);
956
apic_write(APIC_LVT1, APIC_LVT_MASKED);
958
apic_write(APIC_LVTERR, APIC_LVT_MASKED);
960
apic_write(APIC_LVTPC, APIC_LVT_MASKED);
962
/* Integrated APIC (!82489DX) ? */
963
if (lapic_is_integrated()) {
965
/* Clear ESR due to Pentium errata 3AP and 11AP */
966
apic_write(APIC_ESR, 0);
972
* disable_local_APIC - clear and disable the local APIC
974
void disable_local_APIC(void)
978
/* APIC hasn't been mapped yet */
979
if (!x2apic_mode && !apic_phys)
985
* Disable APIC (implies clearing of registers
988
value = apic_read(APIC_SPIV);
989
value &= ~APIC_SPIV_APIC_ENABLED;
990
apic_write(APIC_SPIV, value);
994
* When LAPIC was disabled by the BIOS and enabled by the kernel,
995
* restore the disabled state.
997
if (enabled_via_apicbase) {
1000
rdmsr(MSR_IA32_APICBASE, l, h);
1001
l &= ~MSR_IA32_APICBASE_ENABLE;
1002
wrmsr(MSR_IA32_APICBASE, l, h);
1008
* If Linux enabled the LAPIC against the BIOS default disable it down before
1009
* re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and
1010
* not power-off. Additionally clear all LVT entries before disable_local_APIC
1011
* for the case where Linux didn't enable the LAPIC.
1013
void lapic_shutdown(void)
1015
unsigned long flags;
1017
if (!cpu_has_apic && !apic_from_smp_config())
1020
local_irq_save(flags);
1022
#ifdef CONFIG_X86_32
1023
if (!enabled_via_apicbase)
1027
disable_local_APIC();
1030
local_irq_restore(flags);
1034
* This is to verify that we're looking at a real local APIC.
1035
* Check these against your board if the CPUs aren't getting
1036
* started for no apparent reason.
1038
int __init verify_local_APIC(void)
1040
unsigned int reg0, reg1;
1043
* The version register is read-only in a real APIC.
1045
reg0 = apic_read(APIC_LVR);
1046
apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
1047
apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
1048
reg1 = apic_read(APIC_LVR);
1049
apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
1052
* The two version reads above should print the same
1053
* numbers. If the second one is different, then we
1054
* poke at a non-APIC.
1060
* Check if the version looks reasonably.
1062
reg1 = GET_APIC_VERSION(reg0);
1063
if (reg1 == 0x00 || reg1 == 0xff)
1065
reg1 = lapic_get_maxlvt();
1066
if (reg1 < 0x02 || reg1 == 0xff)
1070
* The ID register is read/write in a real APIC.
1072
reg0 = apic_read(APIC_ID);
1073
apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
1074
apic_write(APIC_ID, reg0 ^ apic->apic_id_mask);
1075
reg1 = apic_read(APIC_ID);
1076
apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
1077
apic_write(APIC_ID, reg0);
1078
if (reg1 != (reg0 ^ apic->apic_id_mask))
1082
* The next two are just to see if we have sane values.
1083
* They're only really relevant if we're in Virtual Wire
1084
* compatibility mode, but most boxes are anymore.
1086
reg0 = apic_read(APIC_LVT0);
1087
apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
1088
reg1 = apic_read(APIC_LVT1);
1089
apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
1095
* sync_Arb_IDs - synchronize APIC bus arbitration IDs
1097
void __init sync_Arb_IDs(void)
1100
* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
1103
if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
1109
apic_wait_icr_idle();
1111
apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
1112
apic_write(APIC_ICR, APIC_DEST_ALLINC |
1113
APIC_INT_LEVELTRIG | APIC_DM_INIT);
1117
* An initial setup of the virtual wire mode.
1119
void __init init_bsp_APIC(void)
1124
* Don't do the setup now if we have a SMP BIOS as the
1125
* through-I/O-APIC virtual wire mode might be active.
1127
if (smp_found_config || !cpu_has_apic)
1131
* Do not trust the local APIC being empty at bootup.
1138
value = apic_read(APIC_SPIV);
1139
value &= ~APIC_VECTOR_MASK;
1140
value |= APIC_SPIV_APIC_ENABLED;
1142
#ifdef CONFIG_X86_32
1143
/* This bit is reserved on P4/Xeon and should be cleared */
1144
if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
1145
(boot_cpu_data.x86 == 15))
1146
value &= ~APIC_SPIV_FOCUS_DISABLED;
1149
value |= APIC_SPIV_FOCUS_DISABLED;
1150
value |= SPURIOUS_APIC_VECTOR;
1151
apic_write(APIC_SPIV, value);
1154
* Set up the virtual wire mode.
1156
apic_write(APIC_LVT0, APIC_DM_EXTINT);
1157
value = APIC_DM_NMI;
1158
if (!lapic_is_integrated()) /* 82489DX */
1159
value |= APIC_LVT_LEVEL_TRIGGER;
1160
apic_write(APIC_LVT1, value);
1163
static void __cpuinit lapic_setup_esr(void)
1165
unsigned int oldvalue, value, maxlvt;
1167
if (!lapic_is_integrated()) {
1168
pr_info("No ESR for 82489DX.\n");
1172
if (apic->disable_esr) {
1174
* Something untraceable is creating bad interrupts on
1175
* secondary quads ... for the moment, just leave the
1176
* ESR disabled - we can't do anything useful with the
1177
* errors anyway - mbligh
1179
pr_info("Leaving ESR disabled.\n");
1183
maxlvt = lapic_get_maxlvt();
1184
if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
1185
apic_write(APIC_ESR, 0);
1186
oldvalue = apic_read(APIC_ESR);
1188
/* enables sending errors */
1189
value = ERROR_APIC_VECTOR;
1190
apic_write(APIC_LVTERR, value);
1193
* spec says clear errors after enabling vector.
1196
apic_write(APIC_ESR, 0);
1197
value = apic_read(APIC_ESR);
1198
if (value != oldvalue)
1199
apic_printk(APIC_VERBOSE, "ESR value before enabling "
1200
"vector: 0x%08x after: 0x%08x\n",
1205
* setup_local_APIC - setup the local APIC
1207
* Used to setup local APIC while initializing BSP or bringin up APs.
1208
* Always called with preemption disabled.
1210
void __cpuinit setup_local_APIC(void)
1212
int cpu = smp_processor_id();
1213
unsigned int value, queued;
1214
int i, j, acked = 0;
1215
unsigned long long tsc = 0, ntsc;
1216
long long max_loops = cpu_khz;
1222
disable_ioapic_support();
1226
#ifdef CONFIG_X86_32
1227
/* Pound the ESR really hard over the head with a big hammer - mbligh */
1228
if (lapic_is_integrated() && apic->disable_esr) {
1229
apic_write(APIC_ESR, 0);
1230
apic_write(APIC_ESR, 0);
1231
apic_write(APIC_ESR, 0);
1232
apic_write(APIC_ESR, 0);
1235
perf_events_lapic_init();
1238
* Double-check whether this APIC is really registered.
1239
* This is meaningless in clustered apic mode, so we skip it.
1241
BUG_ON(!apic->apic_id_registered());
1244
* Intel recommends to set DFR, LDR and TPR before enabling
1245
* an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel
1246
* document number 292116). So here it goes...
1248
apic->init_apic_ldr();
1250
#ifdef CONFIG_X86_32
1252
* APIC LDR is initialized. If logical_apicid mapping was
1253
* initialized during get_smp_config(), make sure it matches the
1256
i = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
1257
WARN_ON(i != BAD_APICID && i != logical_smp_processor_id());
1258
/* always use the value from LDR */
1259
early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
1260
logical_smp_processor_id();
1263
* Some NUMA implementations (NUMAQ) don't initialize apicid to
1264
* node mapping during NUMA init. Now that logical apicid is
1265
* guaranteed to be known, give it another chance. This is already
1266
* a bit too late - percpu allocation has already happened without
1267
* proper NUMA affinity.
1269
if (apic->x86_32_numa_cpu_node)
1270
set_apicid_to_node(early_per_cpu(x86_cpu_to_apicid, cpu),
1271
apic->x86_32_numa_cpu_node(cpu));
1275
* Set Task Priority to 'accept all'. We never change this
1278
value = apic_read(APIC_TASKPRI);
1279
value &= ~APIC_TPRI_MASK;
1280
apic_write(APIC_TASKPRI, value);
1283
* After a crash, we no longer service the interrupts and a pending
1284
* interrupt from previous kernel might still have ISR bit set.
1286
* Most probably by now CPU has serviced that pending interrupt and
1287
* it might not have done the ack_APIC_irq() because it thought,
1288
* interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
1289
* does not clear the ISR bit and cpu thinks it has already serivced
1290
* the interrupt. Hence a vector might get locked. It was noticed
1291
* for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
1295
for (i = APIC_ISR_NR - 1; i >= 0; i--)
1296
queued |= apic_read(APIC_IRR + i*0x10);
1298
for (i = APIC_ISR_NR - 1; i >= 0; i--) {
1299
value = apic_read(APIC_ISR + i*0x10);
1300
for (j = 31; j >= 0; j--) {
1301
if (value & (1<<j)) {
1308
printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n",
1314
max_loops = (cpu_khz << 10) - (ntsc - tsc);
1317
} while (queued && max_loops > 0);
1318
WARN_ON(max_loops <= 0);
1321
* Now that we are all set up, enable the APIC
1323
value = apic_read(APIC_SPIV);
1324
value &= ~APIC_VECTOR_MASK;
1328
value |= APIC_SPIV_APIC_ENABLED;
1330
#ifdef CONFIG_X86_32
1332
* Some unknown Intel IO/APIC (or APIC) errata is biting us with
1333
* certain networking cards. If high frequency interrupts are
1334
* happening on a particular IOAPIC pin, plus the IOAPIC routing
1335
* entry is masked/unmasked at a high rate as well then sooner or
1336
* later IOAPIC line gets 'stuck', no more interrupts are received
1337
* from the device. If focus CPU is disabled then the hang goes
1340
* [ This bug can be reproduced easily with a level-triggered
1341
* PCI Ne2000 networking cards and PII/PIII processors, dual
1345
* Actually disabling the focus CPU check just makes the hang less
1346
* frequent as it makes the interrupt distributon model be more
1347
* like LRU than MRU (the short-term load is more even across CPUs).
1348
* See also the comment in end_level_ioapic_irq(). --macro
1352
* - enable focus processor (bit==0)
1353
* - 64bit mode always use processor focus
1354
* so no need to set it
1356
value &= ~APIC_SPIV_FOCUS_DISABLED;
1360
* Set spurious IRQ vector
1362
value |= SPURIOUS_APIC_VECTOR;
1363
apic_write(APIC_SPIV, value);
1366
* Set up LVT0, LVT1:
1368
* set up through-local-APIC on the BP's LINT0. This is not
1369
* strictly necessary in pure symmetric-IO mode, but sometimes
1370
* we delegate interrupts to the 8259A.
1373
* TODO: set up through-local-APIC from through-I/O-APIC? --macro
1375
value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
1376
if (!cpu && (pic_mode || !value)) {
1377
value = APIC_DM_EXTINT;
1378
apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu);
1380
value = APIC_DM_EXTINT | APIC_LVT_MASKED;
1381
apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu);
1383
apic_write(APIC_LVT0, value);
1386
* only the BP should see the LINT1 NMI signal, obviously.
1389
value = APIC_DM_NMI;
1391
value = APIC_DM_NMI | APIC_LVT_MASKED;
1392
if (!lapic_is_integrated()) /* 82489DX */
1393
value |= APIC_LVT_LEVEL_TRIGGER;
1394
apic_write(APIC_LVT1, value);
1396
#ifdef CONFIG_X86_MCE_INTEL
1397
/* Recheck CMCI information after local APIC is up on CPU #0 */
1403
void __cpuinit end_local_APIC_setup(void)
1407
#ifdef CONFIG_X86_32
1410
/* Disable the local apic timer */
1411
value = apic_read(APIC_LVTT);
1412
value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
1413
apic_write(APIC_LVTT, value);
1420
void __init bsp_end_local_APIC_setup(void)
1422
end_local_APIC_setup();
1425
* Now that local APIC setup is completed for BP, configure the fault
1426
* handling for interrupt remapping.
1428
if (intr_remapping_enabled)
1429
enable_drhd_fault_handling();
1433
#ifdef CONFIG_X86_X2APIC
1434
void check_x2apic(void)
1436
if (x2apic_enabled()) {
1437
pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
1438
x2apic_preenabled = x2apic_mode = 1;
1442
void enable_x2apic(void)
1449
rdmsr(MSR_IA32_APICBASE, msr, msr2);
1450
if (!(msr & X2APIC_ENABLE)) {
1451
printk_once(KERN_INFO "Enabling x2apic\n");
1452
wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, msr2);
1455
#endif /* CONFIG_X86_X2APIC */
1457
int __init enable_IR(void)
1459
#ifdef CONFIG_IRQ_REMAP
1460
if (!intr_remapping_supported()) {
1461
pr_debug("intr-remapping not supported\n");
1465
if (!x2apic_preenabled && skip_ioapic_setup) {
1466
pr_info("Skipped enabling intr-remap because of skipping "
1471
return enable_intr_remapping();
1476
void __init enable_IR_x2apic(void)
1478
unsigned long flags;
1479
int ret, x2apic_enabled = 0;
1480
int dmar_table_init_ret;
1482
dmar_table_init_ret = dmar_table_init();
1483
if (dmar_table_init_ret && !x2apic_supported())
1486
ret = save_ioapic_entries();
1488
pr_info("Saving IO-APIC state failed: %d\n", ret);
1492
local_irq_save(flags);
1493
legacy_pic->mask_all();
1494
mask_ioapic_entries();
1496
if (dmar_table_init_ret)
1502
/* IR is required if there is APIC ID > 255 even when running
1505
if (max_physical_apicid > 255 ||
1506
!hypervisor_x2apic_available())
1509
* without IR all CPUs can be addressed by IOAPIC/MSI
1510
* only in physical mode
1512
x2apic_force_phys();
1515
if (ret == IRQ_REMAP_XAPIC_MODE)
1520
if (x2apic_supported() && !x2apic_mode) {
1523
pr_info("Enabled x2apic\n");
1527
if (ret < 0) /* IR enabling failed */
1528
restore_ioapic_entries();
1529
legacy_pic->restore_mask();
1530
local_irq_restore(flags);
1533
if (x2apic_enabled || !x2apic_supported())
1536
if (x2apic_preenabled)
1537
panic("x2apic: enabled by BIOS but kernel init failed.");
1538
else if (ret == IRQ_REMAP_XAPIC_MODE)
1539
pr_info("x2apic not enabled, IRQ remapping is in xapic mode\n");
1541
pr_info("x2apic not enabled, IRQ remapping init failed\n");
1544
#ifdef CONFIG_X86_64
1546
* Detect and enable local APICs on non-SMP boards.
1547
* Original code written by Keir Fraser.
1548
* On AMD64 we trust the BIOS - if it says no APIC it is likely
1549
* not correctly set up (usually the APIC timer won't work etc.)
1551
static int __init detect_init_APIC(void)
1553
if (!cpu_has_apic) {
1554
pr_info("No local APIC present\n");
1558
mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1563
static int __init apic_verify(void)
1568
* The APIC feature bit should now be enabled
1571
features = cpuid_edx(1);
1572
if (!(features & (1 << X86_FEATURE_APIC))) {
1573
pr_warning("Could not enable APIC!\n");
1576
set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
1577
mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
1579
/* The BIOS may have set up the APIC at some other address */
1580
rdmsr(MSR_IA32_APICBASE, l, h);
1581
if (l & MSR_IA32_APICBASE_ENABLE)
1582
mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
1584
pr_info("Found and enabled local APIC!\n");
1588
int __init apic_force_enable(unsigned long addr)
1596
* Some BIOSes disable the local APIC in the APIC_BASE
1597
* MSR. This can only be done in software for Intel P6 or later
1598
* and AMD K7 (Model > 1) or later.
1600
rdmsr(MSR_IA32_APICBASE, l, h);
1601
if (!(l & MSR_IA32_APICBASE_ENABLE)) {
1602
pr_info("Local APIC disabled by BIOS -- reenabling.\n");
1603
l &= ~MSR_IA32_APICBASE_BASE;
1604
l |= MSR_IA32_APICBASE_ENABLE | addr;
1605
wrmsr(MSR_IA32_APICBASE, l, h);
1606
enabled_via_apicbase = 1;
1608
return apic_verify();
1612
* Detect and initialize APIC
1614
static int __init detect_init_APIC(void)
1616
/* Disabled by kernel option? */
1620
switch (boot_cpu_data.x86_vendor) {
1621
case X86_VENDOR_AMD:
1622
if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
1623
(boot_cpu_data.x86 >= 15))
1626
case X86_VENDOR_INTEL:
1627
if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
1628
(boot_cpu_data.x86 == 5 && cpu_has_apic))
1635
if (!cpu_has_apic) {
1637
* Over-ride BIOS and try to enable the local APIC only if
1638
* "lapic" specified.
1640
if (!force_enable_local_apic) {
1641
pr_info("Local APIC disabled by BIOS -- "
1642
"you can enable it with \"lapic\"\n");
1645
if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
1657
pr_info("No local APIC present or hardware disabled\n");
1663
* init_apic_mappings - initialize APIC mappings
1665
void __init init_apic_mappings(void)
1667
unsigned int new_apicid;
1670
boot_cpu_physical_apicid = read_apic_id();
1674
/* If no local APIC can be found return early */
1675
if (!smp_found_config && detect_init_APIC()) {
1676
/* lets NOP'ify apic operations */
1677
pr_info("APIC: disable apic facility\n");
1680
apic_phys = mp_lapic_addr;
1683
* acpi lapic path already maps that address in
1684
* acpi_register_lapic_address()
1686
if (!acpi_lapic && !smp_found_config)
1687
register_lapic_address(apic_phys);
1691
* Fetch the APIC ID of the BSP in case we have a
1692
* default configuration (or the MP table is broken).
1694
new_apicid = read_apic_id();
1695
if (boot_cpu_physical_apicid != new_apicid) {
1696
boot_cpu_physical_apicid = new_apicid;
1698
* yeah -- we lie about apic_version
1699
* in case if apic was disabled via boot option
1700
* but it's not a problem for SMP compiled kernel
1701
* since smp_sanity_check is prepared for such a case
1702
* and disable smp mode
1704
apic_version[new_apicid] =
1705
GET_APIC_VERSION(apic_read(APIC_LVR));
1709
void __init register_lapic_address(unsigned long address)
1711
mp_lapic_addr = address;
1714
set_fixmap_nocache(FIX_APIC_BASE, address);
1715
apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
1716
APIC_BASE, mp_lapic_addr);
1718
if (boot_cpu_physical_apicid == -1U) {
1719
boot_cpu_physical_apicid = read_apic_id();
1720
apic_version[boot_cpu_physical_apicid] =
1721
GET_APIC_VERSION(apic_read(APIC_LVR));
1726
* This initializes the IO-APIC and APIC hardware if this is
1729
int apic_version[MAX_LOCAL_APIC];
1731
int __init APIC_init_uniprocessor(void)
1734
pr_info("Apic disabled\n");
1737
#ifdef CONFIG_X86_64
1738
if (!cpu_has_apic) {
1740
pr_info("Apic disabled by BIOS\n");
1744
if (!smp_found_config && !cpu_has_apic)
1748
* Complain if the BIOS pretends there is one.
1750
if (!cpu_has_apic &&
1751
APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
1752
pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
1753
boot_cpu_physical_apicid);
1758
default_setup_apic_routing();
1760
verify_local_APIC();
1763
#ifdef CONFIG_X86_64
1764
apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid));
1767
* Hack: In case of kdump, after a crash, kernel might be booting
1768
* on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
1769
* might be zero if read from MP tables. Get it from LAPIC.
1771
# ifdef CONFIG_CRASH_DUMP
1772
boot_cpu_physical_apicid = read_apic_id();
1775
physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
1778
#ifdef CONFIG_X86_IO_APIC
1780
* Now enable IO-APICs, actually call clear_IO_APIC
1781
* We need clear_IO_APIC before enabling error vector
1783
if (!skip_ioapic_setup && nr_ioapics)
1787
bsp_end_local_APIC_setup();
1789
#ifdef CONFIG_X86_IO_APIC
1790
if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
1797
x86_init.timers.setup_percpu_clockev();
1802
* Local APIC interrupts
1806
* This interrupt should _never_ happen with our APIC/SMP architecture
1808
void smp_spurious_interrupt(struct pt_regs *regs)
1815
* Check if this really is a spurious interrupt and ACK it
1816
* if it is a vectored one. Just in case...
1817
* Spurious interrupts should not be ACKed.
1819
v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
1820
if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
1823
inc_irq_stat(irq_spurious_count);
1825
/* see sw-dev-man vol 3, chapter 7.4.13.5 */
1826
pr_info("spurious APIC interrupt on CPU#%d, "
1827
"should never happen.\n", smp_processor_id());
1832
* This interrupt should never happen with our APIC/SMP architecture
1834
void smp_error_interrupt(struct pt_regs *regs)
1838
static const char * const error_interrupt_reason[] = {
1839
"Send CS error", /* APIC Error Bit 0 */
1840
"Receive CS error", /* APIC Error Bit 1 */
1841
"Send accept error", /* APIC Error Bit 2 */
1842
"Receive accept error", /* APIC Error Bit 3 */
1843
"Redirectable IPI", /* APIC Error Bit 4 */
1844
"Send illegal vector", /* APIC Error Bit 5 */
1845
"Received illegal vector", /* APIC Error Bit 6 */
1846
"Illegal register address", /* APIC Error Bit 7 */
1851
/* First tickle the hardware, only then report what went on. -- REW */
1852
v0 = apic_read(APIC_ESR);
1853
apic_write(APIC_ESR, 0);
1854
v1 = apic_read(APIC_ESR);
1856
atomic_inc(&irq_err_count);
1858
apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
1859
smp_processor_id(), v0 , v1);
1864
apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
1869
apic_printk(APIC_DEBUG, KERN_CONT "\n");
1875
* connect_bsp_APIC - attach the APIC to the interrupt system
1877
void __init connect_bsp_APIC(void)
1879
#ifdef CONFIG_X86_32
1882
* Do not trust the local APIC being empty at bootup.
1886
* PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's
1887
* local APIC to INT and NMI lines.
1889
apic_printk(APIC_VERBOSE, "leaving PIC mode, "
1890
"enabling APIC mode.\n");
1894
if (apic->enable_apic_mode)
1895
apic->enable_apic_mode();
1899
* disconnect_bsp_APIC - detach the APIC from the interrupt system
1900
* @virt_wire_setup: indicates, whether virtual wire mode is selected
1902
* Virtual wire mode is necessary to deliver legacy interrupts even when the
1905
void disconnect_bsp_APIC(int virt_wire_setup)
1909
#ifdef CONFIG_X86_32
1912
* Put the board back into PIC mode (has an effect only on
1913
* certain older boards). Note that APIC interrupts, including
1914
* IPIs, won't work beyond this point! The only exception are
1917
apic_printk(APIC_VERBOSE, "disabling APIC mode, "
1918
"entering PIC mode.\n");
1924
/* Go back to Virtual Wire compatibility mode */
1926
/* For the spurious interrupt use vector F, and enable it */
1927
value = apic_read(APIC_SPIV);
1928
value &= ~APIC_VECTOR_MASK;
1929
value |= APIC_SPIV_APIC_ENABLED;
1931
apic_write(APIC_SPIV, value);
1933
if (!virt_wire_setup) {
1935
* For LVT0 make it edge triggered, active high,
1936
* external and enabled
1938
value = apic_read(APIC_LVT0);
1939
value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1940
APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1941
APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1942
value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1943
value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
1944
apic_write(APIC_LVT0, value);
1947
apic_write(APIC_LVT0, APIC_LVT_MASKED);
1951
* For LVT1 make it edge triggered, active high,
1954
value = apic_read(APIC_LVT1);
1955
value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
1956
APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
1957
APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
1958
value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
1959
value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
1960
apic_write(APIC_LVT1, value);
1963
void __cpuinit generic_processor_info(int apicid, int version)
1965
int cpu, max = nr_cpu_ids;
1966
bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
1967
phys_cpu_present_map);
1970
* If boot cpu has not been detected yet, then only allow upto
1971
* nr_cpu_ids - 1 processors and keep one slot free for boot cpu
1973
if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 &&
1974
apicid != boot_cpu_physical_apicid) {
1975
int thiscpu = max + disabled_cpus - 1;
1978
"ACPI: NR_CPUS/possible_cpus limit of %i almost"
1979
" reached. Keeping one slot for boot cpu."
1980
" Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1986
if (num_processors >= nr_cpu_ids) {
1987
int thiscpu = max + disabled_cpus;
1990
"ACPI: NR_CPUS/possible_cpus limit of %i reached."
1991
" Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
1998
if (apicid == boot_cpu_physical_apicid) {
2000
* x86_bios_cpu_apicid is required to have processors listed
2001
* in same order as logical cpu numbers. Hence the first
2002
* entry is BSP, and so on.
2003
* boot_cpu_init() already hold bit 0 in cpu_present_mask
2008
cpu = cpumask_next_zero(-1, cpu_present_mask);
2013
if (version == 0x0) {
2014
pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n",
2018
apic_version[apicid] = version;
2020
if (version != apic_version[boot_cpu_physical_apicid]) {
2021
pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
2022
apic_version[boot_cpu_physical_apicid], cpu, version);
2025
physid_set(apicid, phys_cpu_present_map);
2026
if (apicid > max_physical_apicid)
2027
max_physical_apicid = apicid;
2029
#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
2030
early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
2031
early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
2033
#ifdef CONFIG_X86_32
2034
early_per_cpu(x86_cpu_to_logical_apicid, cpu) =
2035
apic->x86_32_early_logical_apicid(cpu);
2037
set_cpu_possible(cpu, true);
2038
set_cpu_present(cpu, true);
2041
int hard_smp_processor_id(void)
2043
return read_apic_id();
2046
void default_init_apic_ldr(void)
2050
apic_write(APIC_DFR, APIC_DFR_VALUE);
2051
val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
2052
val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
2053
apic_write(APIC_LDR, val);
2063
* 'active' is true if the local APIC was enabled by us and
2064
* not the BIOS; this signifies that we are also responsible
2065
* for disabling it before entering apm/acpi suspend
2068
/* r/w apic fields */
2069
unsigned int apic_id;
2070
unsigned int apic_taskpri;
2071
unsigned int apic_ldr;
2072
unsigned int apic_dfr;
2073
unsigned int apic_spiv;
2074
unsigned int apic_lvtt;
2075
unsigned int apic_lvtpc;
2076
unsigned int apic_lvt0;
2077
unsigned int apic_lvt1;
2078
unsigned int apic_lvterr;
2079
unsigned int apic_tmict;
2080
unsigned int apic_tdcr;
2081
unsigned int apic_thmr;
2084
static int lapic_suspend(void)
2086
unsigned long flags;
2089
if (!apic_pm_state.active)
2092
maxlvt = lapic_get_maxlvt();
2094
apic_pm_state.apic_id = apic_read(APIC_ID);
2095
apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
2096
apic_pm_state.apic_ldr = apic_read(APIC_LDR);
2097
apic_pm_state.apic_dfr = apic_read(APIC_DFR);
2098
apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
2099
apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
2101
apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
2102
apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
2103
apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
2104
apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
2105
apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
2106
apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
2107
#ifdef CONFIG_X86_THERMAL_VECTOR
2109
apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
2112
local_irq_save(flags);
2113
disable_local_APIC();
2115
if (intr_remapping_enabled)
2116
disable_intr_remapping();
2118
local_irq_restore(flags);
2122
static void lapic_resume(void)
2125
unsigned long flags;
2128
if (!apic_pm_state.active)
2131
local_irq_save(flags);
2132
if (intr_remapping_enabled) {
2134
* IO-APIC and PIC have their own resume routines.
2135
* We just mask them here to make sure the interrupt
2136
* subsystem is completely quiet while we enable x2apic
2137
* and interrupt-remapping.
2139
mask_ioapic_entries();
2140
legacy_pic->mask_all();
2147
* Make sure the APICBASE points to the right address
2149
* FIXME! This will be wrong if we ever support suspend on
2150
* SMP! We'll need to do this as part of the CPU restore!
2152
rdmsr(MSR_IA32_APICBASE, l, h);
2153
l &= ~MSR_IA32_APICBASE_BASE;
2154
l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
2155
wrmsr(MSR_IA32_APICBASE, l, h);
2158
maxlvt = lapic_get_maxlvt();
2159
apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
2160
apic_write(APIC_ID, apic_pm_state.apic_id);
2161
apic_write(APIC_DFR, apic_pm_state.apic_dfr);
2162
apic_write(APIC_LDR, apic_pm_state.apic_ldr);
2163
apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
2164
apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
2165
apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
2166
apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
2167
#if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
2169
apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
2172
apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
2173
apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
2174
apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
2175
apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
2176
apic_write(APIC_ESR, 0);
2177
apic_read(APIC_ESR);
2178
apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
2179
apic_write(APIC_ESR, 0);
2180
apic_read(APIC_ESR);
2182
if (intr_remapping_enabled)
2183
reenable_intr_remapping(x2apic_mode);
2185
local_irq_restore(flags);
2189
* This device has no shutdown method - fully functioning local APICs
2190
* are needed on every CPU up until machine_halt/restart/poweroff.
2193
static struct syscore_ops lapic_syscore_ops = {
2194
.resume = lapic_resume,
2195
.suspend = lapic_suspend,
2198
static void __cpuinit apic_pm_activate(void)
2200
apic_pm_state.active = 1;
2203
static int __init init_lapic_sysfs(void)
2205
/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
2207
register_syscore_ops(&lapic_syscore_ops);
2212
/* local apic needs to resume before other devices access its registers. */
2213
core_initcall(init_lapic_sysfs);
2215
#else /* CONFIG_PM */
2217
static void apic_pm_activate(void) { }
2219
#endif /* CONFIG_PM */
2221
#ifdef CONFIG_X86_64
2223
static int __cpuinit apic_cluster_num(void)
2225
int i, clusters, zeros;
2227
u16 *bios_cpu_apicid;
2228
DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
2230
bios_cpu_apicid = early_per_cpu_ptr(x86_bios_cpu_apicid);
2231
bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
2233
for (i = 0; i < nr_cpu_ids; i++) {
2234
/* are we being called early in kernel startup? */
2235
if (bios_cpu_apicid) {
2236
id = bios_cpu_apicid[i];
2237
} else if (i < nr_cpu_ids) {
2239
id = per_cpu(x86_bios_cpu_apicid, i);
2245
if (id != BAD_APICID)
2246
__set_bit(APIC_CLUSTERID(id), clustermap);
2249
/* Problem: Partially populated chassis may not have CPUs in some of
2250
* the APIC clusters they have been allocated. Only present CPUs have
2251
* x86_bios_cpu_apicid entries, thus causing zeroes in the bitmap.
2252
* Since clusters are allocated sequentially, count zeros only if
2253
* they are bounded by ones.
2257
for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
2258
if (test_bit(i, clustermap)) {
2259
clusters += 1 + zeros;
2268
static int __cpuinitdata multi_checked;
2269
static int __cpuinitdata multi;
2271
static int __cpuinit set_multi(const struct dmi_system_id *d)
2275
pr_info("APIC: %s detected, Multi Chassis\n", d->ident);
2280
static const __cpuinitconst struct dmi_system_id multi_dmi_table[] = {
2282
.callback = set_multi,
2283
.ident = "IBM System Summit2",
2285
DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2286
DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"),
2292
static void __cpuinit dmi_check_multi(void)
2297
dmi_check_system(multi_dmi_table);
2302
* apic_is_clustered_box() -- Check if we can expect good TSC
2304
* Thus far, the major user of this is IBM's Summit2 series:
2305
* Clustered boxes may have unsynced TSC problems if they are
2307
* Use DMI to check them
2309
__cpuinit int apic_is_clustered_box(void)
2319
* ScaleMP vSMPowered boxes have one cluster per board and TSCs are
2320
* not guaranteed to be synced between boards
2322
if (apic_cluster_num() > 1)
2330
* APIC command line parameters
2332
static int __init setup_disableapic(char *arg)
2335
setup_clear_cpu_cap(X86_FEATURE_APIC);
2338
early_param("disableapic", setup_disableapic);
2340
/* same as disableapic, for compatibility */
2341
static int __init setup_nolapic(char *arg)
2343
return setup_disableapic(arg);
2345
early_param("nolapic", setup_nolapic);
2347
static int __init parse_lapic_timer_c2_ok(char *arg)
2349
local_apic_timer_c2_ok = 1;
2352
early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
2354
static int __init parse_disable_apic_timer(char *arg)
2356
disable_apic_timer = 1;
2359
early_param("noapictimer", parse_disable_apic_timer);
2361
static int __init parse_nolapic_timer(char *arg)
2363
disable_apic_timer = 1;
2366
early_param("nolapic_timer", parse_nolapic_timer);
2368
static int __init apic_set_verbosity(char *arg)
2371
#ifdef CONFIG_X86_64
2372
skip_ioapic_setup = 0;
2378
if (strcmp("debug", arg) == 0)
2379
apic_verbosity = APIC_DEBUG;
2380
else if (strcmp("verbose", arg) == 0)
2381
apic_verbosity = APIC_VERBOSE;
2383
pr_warning("APIC Verbosity level %s not recognised"
2384
" use apic=verbose or apic=debug\n", arg);
2390
early_param("apic", apic_set_verbosity);
2392
static int __init lapic_insert_resource(void)
2397
/* Put local APIC into the resource map. */
2398
lapic_resource.start = apic_phys;
2399
lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
2400
insert_resource(&iomem_resource, &lapic_resource);
2406
* need call insert after e820_reserve_resources()
2407
* that is using request_resource
2409
late_initcall(lapic_insert_resource);