/* * Local APIC handling, local APIC timers * * (c) 1999, 2000, 2009 Ingo Molnar * * Fixes * Maciej W. Rozycki : Bits for genuine 82489DX APICs; * thanks to Eric Gilmore * and Rolf G. Tews * for testing these extensively. * Maciej W. Rozycki : Various updates and fixes. * Mikael Pettersson : Power Management for UP-APIC. * Pavel Machek and * Mikael Pettersson : PM converted to driver model. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned int num_processors; unsigned disabled_cpus; /* Processor that is doing the boot up */ unsigned int boot_cpu_physical_apicid = -1U; EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid); /* * The highest APIC ID seen during enumeration. */ static unsigned int max_physical_apicid; /* * Bitmask of physically existing CPUs: */ physid_mask_t phys_cpu_present_map; /* * Processor to be disabled specified by kernel parameter * disable_cpu_apicid=, mostly used for the kdump 2nd kernel to * avoid undefined behaviour caused by sending INIT from AP to BSP. */ static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID; /* * This variable controls which CPUs receive external NMIs. By default, * external NMIs are delivered only to the BSP. */ static int apic_extnmi = APIC_EXTNMI_BSP; /* * Map cpu index to physical APIC ID */ DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_cpu_to_apicid, BAD_APICID); DEFINE_EARLY_PER_CPU_READ_MOSTLY(u16, x86_bios_cpu_apicid, BAD_APICID); DEFINE_EARLY_PER_CPU_READ_MOSTLY(u32, x86_cpu_to_acpiid, U32_MAX); EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid); EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid); EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid); #ifdef CONFIG_X86_32 /* * On x86_32, the mapping between cpu and logical apicid may vary * depending on apic in use. The following early percpu variable is * used for the mapping. This is where the behaviors of x86_64 and 32 * actually diverge. Let's keep it ugly for now. */ DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID); /* Local APIC was disabled by the BIOS and enabled by the kernel */ static int enabled_via_apicbase; /* * Handle interrupt mode configuration register (IMCR). * This register controls whether the interrupt signals * that reach the BSP come from the master PIC or from the * local APIC. Before entering Symmetric I/O Mode, either * the BIOS or the operating system must switch out of * PIC Mode by changing the IMCR. */ static inline void imcr_pic_to_apic(void) { /* select IMCR register */ outb(0x70, 0x22); /* NMI and 8259 INTR go through APIC */ outb(0x01, 0x23); } static inline void imcr_apic_to_pic(void) { /* select IMCR register */ outb(0x70, 0x22); /* NMI and 8259 INTR go directly to BSP */ outb(0x00, 0x23); } #endif /* * Knob to control our willingness to enable the local APIC. * * +1=force-enable */ static int force_enable_local_apic __initdata; /* * APIC command line parameters */ static int __init parse_lapic(char *arg) { if (IS_ENABLED(CONFIG_X86_32) && !arg) force_enable_local_apic = 1; else if (arg && !strncmp(arg, "notscdeadline", 13)) setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER); return 0; } early_param("lapic", parse_lapic); #ifdef CONFIG_X86_64 static int apic_calibrate_pmtmr __initdata; static __init int setup_apicpmtimer(char *s) { apic_calibrate_pmtmr = 1; notsc_setup(NULL); return 0; } __setup("apicpmtimer", setup_apicpmtimer); #endif unsigned long mp_lapic_addr; int disable_apic; /* Disable local APIC timer from the kernel commandline or via dmi quirk */ static int disable_apic_timer __initdata; /* Local APIC timer works in C2 */ int local_apic_timer_c2_ok; EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok); int first_system_vector = FIRST_SYSTEM_VECTOR; /* * Debug level, exported for io_apic.c */ unsigned int apic_verbosity; int pic_mode; /* Have we found an MP table */ int smp_found_config; static struct resource lapic_resource = { .name = "Local APIC", .flags = IORESOURCE_MEM | IORESOURCE_BUSY, }; unsigned int lapic_timer_frequency = 0; static void apic_pm_activate(void); static unsigned long apic_phys; /* * Get the LAPIC version */ static inline int lapic_get_version(void) { return GET_APIC_VERSION(apic_read(APIC_LVR)); } /* * Check, if the APIC is integrated or a separate chip */ static inline int lapic_is_integrated(void) { #ifdef CONFIG_X86_64 return 1; #else return APIC_INTEGRATED(lapic_get_version()); #endif } /* * Check, whether this is a modern or a first generation APIC */ static int modern_apic(void) { /* AMD systems use old APIC versions, so check the CPU */ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && boot_cpu_data.x86 >= 0xf) return 1; return lapic_get_version() >= 0x14; } /* * right after this call apic become NOOP driven * so apic->write/read doesn't do anything */ static void __init apic_disable(void) { pr_info("APIC: switched to apic NOOP\n"); apic = &apic_noop; } void native_apic_wait_icr_idle(void) { while (apic_read(APIC_ICR) & APIC_ICR_BUSY) cpu_relax(); } u32 native_safe_apic_wait_icr_idle(void) { u32 send_status; int timeout; timeout = 0; do { send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY; if (!send_status) break; inc_irq_stat(icr_read_retry_count); udelay(100); } while (timeout++ < 1000); return send_status; } void native_apic_icr_write(u32 low, u32 id) { unsigned long flags; local_irq_save(flags); apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id)); apic_write(APIC_ICR, low); local_irq_restore(flags); } u64 native_apic_icr_read(void) { u32 icr1, icr2; icr2 = apic_read(APIC_ICR2); icr1 = apic_read(APIC_ICR); return icr1 | ((u64)icr2 << 32); } #ifdef CONFIG_X86_32 /** * get_physical_broadcast - Get number of physical broadcast IDs */ int get_physical_broadcast(void) { return modern_apic() ? 0xff : 0xf; } #endif /** * lapic_get_maxlvt - get the maximum number of local vector table entries */ int lapic_get_maxlvt(void) { unsigned int v; v = apic_read(APIC_LVR); /* * - we always have APIC integrated on 64bit mode * - 82489DXs do not report # of LVT entries */ return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2; } /* * Local APIC timer */ /* Clock divisor */ #define APIC_DIVISOR 16 #define TSC_DIVISOR 8 /* * This function sets up the local APIC timer, with a timeout of * 'clocks' APIC bus clock. During calibration we actually call * this function twice on the boot CPU, once with a bogus timeout * value, second time for real. The other (noncalibrating) CPUs * call this function only once, with the real, calibrated value. * * We do reads before writes even if unnecessary, to get around the * P5 APIC double write bug. */ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen) { unsigned int lvtt_value, tmp_value; lvtt_value = LOCAL_TIMER_VECTOR; if (!oneshot) lvtt_value |= APIC_LVT_TIMER_PERIODIC; else if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) lvtt_value |= APIC_LVT_TIMER_TSCDEADLINE; if (!lapic_is_integrated()) lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV); if (!irqen) lvtt_value |= APIC_LVT_MASKED; apic_write(APIC_LVTT, lvtt_value); if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) { /* * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode, * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized. * According to Intel, MFENCE can do the serialization here. */ asm volatile("mfence" : : : "memory"); printk_once(KERN_DEBUG "TSC deadline timer enabled\n"); return; } /* * Divide PICLK by 16 */ tmp_value = apic_read(APIC_TDCR); apic_write(APIC_TDCR, (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) | APIC_TDR_DIV_16); if (!oneshot) apic_write(APIC_TMICT, clocks / APIC_DIVISOR); } /* * Setup extended LVT, AMD specific * * Software should use the LVT offsets the BIOS provides. The offsets * are determined by the subsystems using it like those for MCE * threshold or IBS. On K8 only offset 0 (APIC500) and MCE interrupts * are supported. Beginning with family 10h at least 4 offsets are * available. * * Since the offsets must be consistent for all cores, we keep track * of the LVT offsets in software and reserve the offset for the same * vector also to be used on other cores. An offset is freed by * setting the entry to APIC_EILVT_MASKED. * * If the BIOS is right, there should be no conflicts. Otherwise a * "[Firmware Bug]: ..." error message is generated. However, if * software does not properly determines the offsets, it is not * necessarily a BIOS bug. */ static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX]; static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new) { return (old & APIC_EILVT_MASKED) || (new == APIC_EILVT_MASKED) || ((new & ~APIC_EILVT_MASKED) == old); } static unsigned int reserve_eilvt_offset(int offset, unsigned int new) { unsigned int rsvd, vector; if (offset >= APIC_EILVT_NR_MAX) return ~0; rsvd = atomic_read(&eilvt_offsets[offset]); do { vector = rsvd & ~APIC_EILVT_MASKED; /* 0: unassigned */ if (vector && !eilvt_entry_is_changeable(vector, new)) /* may not change if vectors are different */ return rsvd; rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new); } while (rsvd != new); rsvd &= ~APIC_EILVT_MASKED; if (rsvd && rsvd != vector) pr_info("LVT offset %d assigned for vector 0x%02x\n", offset, rsvd); return new; } /* * If mask=1, the LVT entry does not generate interrupts while mask=0 * enables the vector. See also the BKDGs. Must be called with * preemption disabled. */ int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask) { unsigned long reg = APIC_EILVTn(offset); unsigned int new, old, reserved; new = (mask << 16) | (msg_type << 8) | vector; old = apic_read(reg); reserved = reserve_eilvt_offset(offset, new); if (reserved != new) { pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for " "vector 0x%x, but the register is already in use for " "vector 0x%x on another cpu\n", smp_processor_id(), reg, offset, new, reserved); return -EINVAL; } if (!eilvt_entry_is_changeable(old, new)) { pr_err(FW_BUG "cpu %d, try to use APIC%lX (LVT offset %d) for " "vector 0x%x, but the register is already in use for " "vector 0x%x on this cpu\n", smp_processor_id(), reg, offset, new, old); return -EBUSY; } apic_write(reg, new); return 0; } EXPORT_SYMBOL_GPL(setup_APIC_eilvt); /* * Program the next event, relative to now */ static int lapic_next_event(unsigned long delta, struct clock_event_device *evt) { apic_write(APIC_TMICT, delta); return 0; } static int lapic_next_deadline(unsigned long delta, struct clock_event_device *evt) { u64 tsc; tsc = rdtsc(); wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR)); return 0; } static int lapic_timer_shutdown(struct clock_event_device *evt) { unsigned int v; /* Lapic used as dummy for broadcast ? */ if (evt->features & CLOCK_EVT_FEAT_DUMMY) return 0; v = apic_read(APIC_LVTT); v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); apic_write(APIC_LVTT, v); apic_write(APIC_TMICT, 0); return 0; } static inline int lapic_timer_set_periodic_oneshot(struct clock_event_device *evt, bool oneshot) { /* Lapic used as dummy for broadcast ? */ if (evt->features & CLOCK_EVT_FEAT_DUMMY) return 0; __setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1); return 0; } static int lapic_timer_set_periodic(struct clock_event_device *evt) { return lapic_timer_set_periodic_oneshot(evt, false); } static int lapic_timer_set_oneshot(struct clock_event_device *evt) { return lapic_timer_set_periodic_oneshot(evt, true); } /* * Local APIC timer broadcast function */ static void lapic_timer_broadcast(const struct cpumask *mask) { #ifdef CONFIG_SMP apic->send_IPI_mask(mask, LOCAL_TIMER_VECTOR); #endif } /* * The local apic timer can be used for any function which is CPU local. */ static struct clock_event_device lapic_clockevent = { .name = "lapic", .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY, .shift = 32, .set_state_shutdown = lapic_timer_shutdown, .set_state_periodic = lapic_timer_set_periodic, .set_state_oneshot = lapic_timer_set_oneshot, .set_next_event = lapic_next_event, .broadcast = lapic_timer_broadcast, .rating = 100, .irq = -1, }; static DEFINE_PER_CPU(struct clock_event_device, lapic_events); /* * Setup the local APIC timer for this CPU. Copy the initialized values * of the boot CPU and register the clock event in the framework. */ static void setup_APIC_timer(void) { struct clock_event_device *levt = this_cpu_ptr(&lapic_events); if (this_cpu_has(X86_FEATURE_ARAT)) { lapic_clockevent.features &= ~CLOCK_EVT_FEAT_C3STOP; /* Make LAPIC timer preferrable over percpu HPET */ lapic_clockevent.rating = 150; } memcpy(levt, &lapic_clockevent, sizeof(*levt)); levt->cpumask = cpumask_of(smp_processor_id()); if (this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) { levt->features &= ~(CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_DUMMY); levt->set_next_event = lapic_next_deadline; clockevents_config_and_register(levt, tsc_khz * (1000 / TSC_DIVISOR), 0xF, ~0UL); } else clockevents_register_device(levt); } /* * Install the updated TSC frequency from recalibration at the TSC * deadline clockevent devices. */ static void __lapic_update_tsc_freq(void *info) { struct clock_event_device *levt = this_cpu_ptr(&lapic_events); if (!this_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) return; clockevents_update_freq(levt, tsc_khz * (1000 / TSC_DIVISOR)); } void lapic_update_tsc_freq(void) { /* * The clockevent device's ->mult and ->shift can both be * changed. In order to avoid races, schedule the frequency * update code on each CPU. */ on_each_cpu(__lapic_update_tsc_freq, NULL, 0); } /* * In this functions we calibrate APIC bus clocks to the external timer. * * We want to do the calibration only once since we want to have local timer * irqs syncron. CPUs connected by the same APIC bus have the very same bus * frequency. * * This was previously done by reading the PIT/HPET and waiting for a wrap * around to find out, that a tick has elapsed. I have a box, where the PIT * readout is broken, so it never gets out of the wait loop again. This was * also reported by others. * * Monitoring the jiffies value is inaccurate and the clockevents * infrastructure allows us to do a simple substitution of the interrupt * handler. * * The calibration routine also uses the pm_timer when possible, as the PIT * happens to run way too slow (factor 2.3 on my VAIO CoreDuo, which goes * back to normal later in the boot process). */ #define LAPIC_CAL_LOOPS (HZ/10) static __initdata int lapic_cal_loops = -1; static __initdata long lapic_cal_t1, lapic_cal_t2; static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2; static __initdata unsigned long lapic_cal_pm1, lapic_cal_pm2; static __initdata unsigned long lapic_cal_j1, lapic_cal_j2; /* * Temporary interrupt handler. */ static void __init lapic_cal_handler(struct clock_event_device *dev) { unsigned long long tsc = 0; long tapic = apic_read(APIC_TMCCT); unsigned long pm = acpi_pm_read_early(); if (boot_cpu_has(X86_FEATURE_TSC)) tsc = rdtsc(); switch (lapic_cal_loops++) { case 0: lapic_cal_t1 = tapic; lapic_cal_tsc1 = tsc; lapic_cal_pm1 = pm; lapic_cal_j1 = jiffies; break; case LAPIC_CAL_LOOPS: lapic_cal_t2 = tapic; lapic_cal_tsc2 = tsc; if (pm < lapic_cal_pm1) pm += ACPI_PM_OVRRUN; lapic_cal_pm2 = pm; lapic_cal_j2 = jiffies; break; } } static int __init calibrate_by_pmtimer(long deltapm, long *delta, long *deltatsc) { const long pm_100ms = PMTMR_TICKS_PER_SEC / 10; const long pm_thresh = pm_100ms / 100; unsigned long mult; u64 res; #ifndef CONFIG_X86_PM_TIMER return -1; #endif apic_printk(APIC_VERBOSE, "... PM-Timer delta = %ld\n", deltapm); /* Check, if the PM timer is available */ if (!deltapm) return -1; mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, 22); if (deltapm > (pm_100ms - pm_thresh) && deltapm < (pm_100ms + pm_thresh)) { apic_printk(APIC_VERBOSE, "... PM-Timer result ok\n"); return 0; } res = (((u64)deltapm) * mult) >> 22; do_div(res, 1000000); pr_warning("APIC calibration not consistent " "with PM-Timer: %ldms instead of 100ms\n",(long)res); /* Correct the lapic counter value */ res = (((u64)(*delta)) * pm_100ms); do_div(res, deltapm); pr_info("APIC delta adjusted to PM-Timer: " "%lu (%ld)\n", (unsigned long)res, *delta); *delta = (long)res; /* Correct the tsc counter value */ if (boot_cpu_has(X86_FEATURE_TSC)) { res = (((u64)(*deltatsc)) * pm_100ms); do_div(res, deltapm); apic_printk(APIC_VERBOSE, "TSC delta adjusted to " "PM-Timer: %lu (%ld)\n", (unsigned long)res, *deltatsc); *deltatsc = (long)res; } return 0; } static int __init calibrate_APIC_clock(void) { struct clock_event_device *levt = this_cpu_ptr(&lapic_events); void (*real_handler)(struct clock_event_device *dev); unsigned long deltaj; long delta, deltatsc; int pm_referenced = 0; /** * check if lapic timer has already been calibrated by platform * specific routine, such as tsc calibration code. if so, we just fill * in the clockevent structure and return. */ if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) { return 0; } else if (lapic_timer_frequency) { apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n", lapic_timer_frequency); lapic_clockevent.mult = div_sc(lapic_timer_frequency/APIC_DIVISOR, TICK_NSEC, lapic_clockevent.shift); lapic_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFF, &lapic_clockevent); lapic_clockevent.min_delta_ns = clockevent_delta2ns(0xF, &lapic_clockevent); lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY; return 0; } apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n" "calibrating APIC timer ...\n"); local_irq_disable(); /* Replace the global interrupt handler */ real_handler = global_clock_event->event_handler; global_clock_event->event_handler = lapic_cal_handler; /* * Setup the APIC counter to maximum. There is no way the lapic * can underflow in the 100ms detection time frame */ __setup_APIC_LVTT(0xffffffff, 0, 0); /* Let the interrupts run */ local_irq_enable(); while (lapic_cal_loops <= LAPIC_CAL_LOOPS) cpu_relax(); local_irq_disable(); /* Restore the real event handler */ global_clock_event->event_handler = real_handler; /* Build delta t1-t2 as apic timer counts down */ delta = lapic_cal_t1 - lapic_cal_t2; apic_printk(APIC_VERBOSE, "... lapic delta = %ld\n", delta); deltatsc = (long)(lapic_cal_tsc2 - lapic_cal_tsc1); /* we trust the PM based calibration if possible */ pm_referenced = !calibrate_by_pmtimer(lapic_cal_pm2 - lapic_cal_pm1, &delta, &deltatsc); /* Calculate the scaled math multiplication factor */ lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS, lapic_clockevent.shift); lapic_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, &lapic_clockevent); lapic_clockevent.min_delta_ns = clockevent_delta2ns(0xF, &lapic_clockevent); lapic_timer_frequency = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS; apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta); apic_printk(APIC_VERBOSE, "..... mult: %u\n", lapic_clockevent.mult); apic_printk(APIC_VERBOSE, "..... calibration result: %u\n", lapic_timer_frequency); if (boot_cpu_has(X86_FEATURE_TSC)) { apic_printk(APIC_VERBOSE, "..... CPU clock speed is " "%ld.%04ld MHz.\n", (deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ), (deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ)); } apic_printk(APIC_VERBOSE, "..... host bus clock speed is " "%u.%04u MHz.\n", lapic_timer_frequency / (1000000 / HZ), lapic_timer_frequency % (1000000 / HZ)); /* * Do a sanity check on the APIC calibration result */ if (lapic_timer_frequency < (1000000 / HZ)) { local_irq_enable(); pr_warning("APIC frequency too slow, disabling apic timer\n"); return -1; } levt->features &= ~CLOCK_EVT_FEAT_DUMMY; /* * PM timer calibration failed or not turned on * so lets try APIC timer based calibration */ if (!pm_referenced) { apic_printk(APIC_VERBOSE, "... verify APIC timer\n"); /* * Setup the apic timer manually */ levt->event_handler = lapic_cal_handler; lapic_timer_set_periodic(levt); lapic_cal_loops = -1; /* Let the interrupts run */ local_irq_enable(); while (lapic_cal_loops <= LAPIC_CAL_LOOPS) cpu_relax(); /* Stop the lapic timer */ local_irq_disable(); lapic_timer_shutdown(levt); /* Jiffies delta */ deltaj = lapic_cal_j2 - lapic_cal_j1; apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj); /* Check, if the jiffies result is consistent */ if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2) apic_printk(APIC_VERBOSE, "... jiffies result ok\n"); else levt->features |= CLOCK_EVT_FEAT_DUMMY; } local_irq_enable(); if (levt->features & CLOCK_EVT_FEAT_DUMMY) { pr_warning("APIC timer disabled due to verification failure\n"); return -1; } return 0; } /* * Setup the boot APIC * * Calibrate and verify the result. */ void __init setup_boot_APIC_clock(void) { /* * The local apic timer can be disabled via the kernel * commandline or from the CPU detection code. Register the lapic * timer as a dummy clock event source on SMP systems, so the * broadcast mechanism is used. On UP systems simply ignore it. */ if (disable_apic_timer) { pr_info("Disabling APIC timer\n"); /* No broadcast on UP ! */ if (num_possible_cpus() > 1) { lapic_clockevent.mult = 1; setup_APIC_timer(); } return; } if (calibrate_APIC_clock()) { /* No broadcast on UP ! */ if (num_possible_cpus() > 1) setup_APIC_timer(); return; } /* * If nmi_watchdog is set to IO_APIC, we need the * PIT/HPET going. Otherwise register lapic as a dummy * device. */ lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY; /* Setup the lapic or request the broadcast */ setup_APIC_timer(); } void setup_secondary_APIC_clock(void) { setup_APIC_timer(); } /* * The guts of the apic timer interrupt */ static void local_apic_timer_interrupt(void) { int cpu = smp_processor_id(); struct clock_event_device *evt = &per_cpu(lapic_events, cpu); /* * Normally we should not be here till LAPIC has been initialized but * in some cases like kdump, its possible that there is a pending LAPIC * timer interrupt from previous kernel's context and is delivered in * new kernel the moment interrupts are enabled. * * Interrupts are enabled early and LAPIC is setup much later, hence * its possible that when we get here evt->event_handler is NULL. * Check for event_handler being NULL and discard the interrupt as * spurious. */ if (!evt->event_handler) { pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu); /* Switch it off */ lapic_timer_shutdown(evt); return; } /* * the NMI deadlock-detector uses this. */ inc_irq_stat(apic_timer_irqs); evt->event_handler(evt); } /* * Local APIC timer interrupt. This is the most natural way for doing * local interrupts, but local timer interrupts can be emulated by * broadcast interrupts too. [in case the hw doesn't support APIC timers] * * [ if a single-CPU system runs an SMP kernel then we call the local * interrupt as well. Thus we cannot inline the local irq ... ] */ __visible void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); /* * NOTE! We'd better ACK the irq immediately, * because timer handling can be slow. * * update_process_times() expects us to have done irq_enter(). * Besides, if we don't timer interrupts ignore the global * interrupt lock, which is the WrongThing (tm) to do. */ entering_ack_irq(); local_apic_timer_interrupt(); exiting_irq(); set_irq_regs(old_regs); } __visible void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); /* * NOTE! We'd better ACK the irq immediately, * because timer handling can be slow. * * update_process_times() expects us to have done irq_enter(). * Besides, if we don't timer interrupts ignore the global * interrupt lock, which is the WrongThing (tm) to do. */ entering_ack_irq(); trace_local_timer_entry(LOCAL_TIMER_VECTOR); local_apic_timer_interrupt(); trace_local_timer_exit(LOCAL_TIMER_VECTOR); exiting_irq(); set_irq_regs(old_regs); } int setup_profiling_timer(unsigned int multiplier) { return -EINVAL; } /* * Local APIC start and shutdown */ /** * clear_local_APIC - shutdown the local APIC * * This is called, when a CPU is disabled and before rebooting, so the state of * the local APIC has no dangling leftovers. Also used to cleanout any BIOS * leftovers during boot. */ void clear_local_APIC(void) { int maxlvt; u32 v; /* APIC hasn't been mapped yet */ if (!x2apic_mode && !apic_phys) return; maxlvt = lapic_get_maxlvt(); /* * Masking an LVT entry can trigger a local APIC error * if the vector is zero. Mask LVTERR first to prevent this. */ if (maxlvt >= 3) { v = ERROR_APIC_VECTOR; /* any non-zero vector will do */ apic_write(APIC_LVTERR, v | APIC_LVT_MASKED); } /* * Careful: we have to set masks only first to deassert * any level-triggered sources. */ v = apic_read(APIC_LVTT); apic_write(APIC_LVTT, v | APIC_LVT_MASKED); v = apic_read(APIC_LVT0); apic_write(APIC_LVT0, v | APIC_LVT_MASKED); v = apic_read(APIC_LVT1); apic_write(APIC_LVT1, v | APIC_LVT_MASKED); if (maxlvt >= 4) { v = apic_read(APIC_LVTPC); apic_write(APIC_LVTPC, v | APIC_LVT_MASKED); } /* lets not touch this if we didn't frob it */ #ifdef CONFIG_X86_THERMAL_VECTOR if (maxlvt >= 5) { v = apic_read(APIC_LVTTHMR); apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED); } #endif #ifdef CONFIG_X86_MCE_INTEL if (maxlvt >= 6) { v = apic_read(APIC_LVTCMCI); if (!(v & APIC_LVT_MASKED)) apic_write(APIC_LVTCMCI, v | APIC_LVT_MASKED); } #endif /* * Clean APIC state for other OSs: */ apic_write(APIC_LVTT, APIC_LVT_MASKED); apic_write(APIC_LVT0, APIC_LVT_MASKED); apic_write(APIC_LVT1, APIC_LVT_MASKED); if (maxlvt >= 3) apic_write(APIC_LVTERR, APIC_LVT_MASKED); if (maxlvt >= 4) apic_write(APIC_LVTPC, APIC_LVT_MASKED); /* Integrated APIC (!82489DX) ? */ if (lapic_is_integrated()) { if (maxlvt > 3) /* Clear ESR due to Pentium errata 3AP and 11AP */ apic_write(APIC_ESR, 0); apic_read(APIC_ESR); } } /** * disable_local_APIC - clear and disable the local APIC */ void disable_local_APIC(void) { unsigned int value; /* APIC hasn't been mapped yet */ if (!x2apic_mode && !apic_phys) return; clear_local_APIC(); /* * Disable APIC (implies clearing of registers * for 82489DX!). */ value = apic_read(APIC_SPIV); value &= ~APIC_SPIV_APIC_ENABLED; apic_write(APIC_SPIV, value); #ifdef CONFIG_X86_32 /* * When LAPIC was disabled by the BIOS and enabled by the kernel, * restore the disabled state. */ if (enabled_via_apicbase) { unsigned int l, h; rdmsr(MSR_IA32_APICBASE, l, h); l &= ~MSR_IA32_APICBASE_ENABLE; wrmsr(MSR_IA32_APICBASE, l, h); } #endif } /* * If Linux enabled the LAPIC against the BIOS default disable it down before * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and * not power-off. Additionally clear all LVT entries before disable_local_APIC * for the case where Linux didn't enable the LAPIC. */ void lapic_shutdown(void) { unsigned long flags; if (!boot_cpu_has(X86_FEATURE_APIC) && !apic_from_smp_config()) return; local_irq_save(flags); #ifdef CONFIG_X86_32 if (!enabled_via_apicbase) clear_local_APIC(); else #endif disable_local_APIC(); local_irq_restore(flags); } /** * sync_Arb_IDs - synchronize APIC bus arbitration IDs */ void __init sync_Arb_IDs(void) { /* * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not * needed on AMD. */ if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD) return; /* * Wait for idle. */ apic_wait_icr_idle(); apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n"); apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG | APIC_DM_INIT); } /* * An initial setup of the virtual wire mode. */ void __init init_bsp_APIC(void) { unsigned int value; /* * Don't do the setup now if we have a SMP BIOS as the * through-I/O-APIC virtual wire mode might be active. */ if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC)) return; /* * Do not trust the local APIC being empty at bootup. */ clear_local_APIC(); /* * Enable APIC. */ value = apic_read(APIC_SPIV); value &= ~APIC_VECTOR_MASK; value |= APIC_SPIV_APIC_ENABLED; #ifdef CONFIG_X86_32 /* This bit is reserved on P4/Xeon and should be cleared */ if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 15)) value &= ~APIC_SPIV_FOCUS_DISABLED; else #endif value |= APIC_SPIV_FOCUS_DISABLED; value |= SPURIOUS_APIC_VECTOR; apic_write(APIC_SPIV, value); /* * Set up the virtual wire mode. */ apic_write(APIC_LVT0, APIC_DM_EXTINT); value = APIC_DM_NMI; if (!lapic_is_integrated()) /* 82489DX */ value |= APIC_LVT_LEVEL_TRIGGER; if (apic_extnmi == APIC_EXTNMI_NONE) value |= APIC_LVT_MASKED; apic_write(APIC_LVT1, value); } static void lapic_setup_esr(void) { unsigned int oldvalue, value, maxlvt; if (!lapic_is_integrated()) { pr_info("No ESR for 82489DX.\n"); return; } if (apic->disable_esr) { /* * Something untraceable is creating bad interrupts on * secondary quads ... for the moment, just leave the * ESR disabled - we can't do anything useful with the * errors anyway - mbligh */ pr_info("Leaving ESR disabled.\n"); return; } maxlvt = lapic_get_maxlvt(); if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */ apic_write(APIC_ESR, 0); oldvalue = apic_read(APIC_ESR); /* enables sending errors */ value = ERROR_APIC_VECTOR; apic_write(APIC_LVTERR, value); /* * spec says clear errors after enabling vector. */ if (maxlvt > 3) apic_write(APIC_ESR, 0); value = apic_read(APIC_ESR); if (value != oldvalue) apic_printk(APIC_VERBOSE, "ESR value before enabling " "vector: 0x%08x after: 0x%08x\n", oldvalue, value); } /** * setup_local_APIC - setup the local APIC * * Used to setup local APIC while initializing BSP or bringin up APs. * Always called with preemption disabled. */ void setup_local_APIC(void) { int cpu = smp_processor_id(); unsigned int value, queued; int i, j, acked = 0; unsigned long long tsc = 0, ntsc; long long max_loops = cpu_khz ? cpu_khz : 1000000; if (boot_cpu_has(X86_FEATURE_TSC)) tsc = rdtsc(); if (disable_apic) { disable_ioapic_support(); return; } #ifdef CONFIG_X86_32 /* Pound the ESR really hard over the head with a big hammer - mbligh */ if (lapic_is_integrated() && apic->disable_esr) { apic_write(APIC_ESR, 0); apic_write(APIC_ESR, 0); apic_write(APIC_ESR, 0); apic_write(APIC_ESR, 0); } #endif perf_events_lapic_init(); /* * Double-check whether this APIC is really registered. * This is meaningless in clustered apic mode, so we skip it. */ BUG_ON(!apic->apic_id_registered()); /* * Intel recommends to set DFR, LDR and TPR before enabling * an APIC. See e.g. "AP-388 82489DX User's Manual" (Intel * document number 292116). So here it goes... */ apic->init_apic_ldr(); #ifdef CONFIG_X86_32 /* * APIC LDR is initialized. If logical_apicid mapping was * initialized during get_smp_config(), make sure it matches the * actual value. */ i = early_per_cpu(x86_cpu_to_logical_apicid, cpu); WARN_ON(i != BAD_APICID && i != logical_smp_processor_id()); /* always use the value from LDR */ early_per_cpu(x86_cpu_to_logical_apicid, cpu) = logical_smp_processor_id(); #endif /* * Set Task Priority to 'accept all'. We never change this * later on. */ value = apic_read(APIC_TASKPRI); value &= ~APIC_TPRI_MASK; apic_write(APIC_TASKPRI, value); /* * After a crash, we no longer service the interrupts and a pending * interrupt from previous kernel might still have ISR bit set. * * Most probably by now CPU has serviced that pending interrupt and * it might not have done the ack_APIC_irq() because it thought, * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it * does not clear the ISR bit and cpu thinks it has already serivced * the interrupt. Hence a vector might get locked. It was noticed * for timer irq (vector 0x31). Issue an extra EOI to clear ISR. */ do { queued = 0; for (i = APIC_ISR_NR - 1; i >= 0; i--) queued |= apic_read(APIC_IRR + i*0x10); for (i = APIC_ISR_NR - 1; i >= 0; i--) { value = apic_read(APIC_ISR + i*0x10); for (j = 31; j >= 0; j--) { if (value & (1< 256) { printk(KERN_ERR "LAPIC pending interrupts after %d EOI\n", acked); break; } if (queued) { if (boot_cpu_has(X86_FEATURE_TSC) && cpu_khz) { ntsc = rdtsc(); max_loops = (cpu_khz << 10) - (ntsc - tsc); } else max_loops--; } } while (queued && max_loops > 0); WARN_ON(max_loops <= 0); /* * Now that we are all set up, enable the APIC */ value = apic_read(APIC_SPIV); value &= ~APIC_VECTOR_MASK; /* * Enable APIC */ value |= APIC_SPIV_APIC_ENABLED; #ifdef CONFIG_X86_32 /* * Some unknown Intel IO/APIC (or APIC) errata is biting us with * certain networking cards. If high frequency interrupts are * happening on a particular IOAPIC pin, plus the IOAPIC routing * entry is masked/unmasked at a high rate as well then sooner or * later IOAPIC line gets 'stuck', no more interrupts are received * from the device. If focus CPU is disabled then the hang goes * away, oh well :-( * * [ This bug can be reproduced easily with a level-triggered * PCI Ne2000 networking cards and PII/PIII processors, dual * BX chipset. ] */ /* * Actually disabling the focus CPU check just makes the hang less * frequent as it makes the interrupt distributon model be more * like LRU than MRU (the short-term load is more even across CPUs). * See also the comment in end_level_ioapic_irq(). --macro */ /* * - enable focus processor (bit==0) * - 64bit mode always use processor focus * so no need to set it */ value &= ~APIC_SPIV_FOCUS_DISABLED; #endif /* * Set spurious IRQ vector */ value |= SPURIOUS_APIC_VECTOR; apic_write(APIC_SPIV, value); /* * Set up LVT0, LVT1: * * set up through-local-APIC on the BP's LINT0. This is not * strictly necessary in pure symmetric-IO mode, but sometimes * we delegate interrupts to the 8259A. */ /* * TODO: set up through-local-APIC from through-I/O-APIC? --macro */ value = apic_read(APIC_LVT0) & APIC_LVT_MASKED; if (!cpu && (pic_mode || !value)) { value = APIC_DM_EXTINT; apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu); } else { value = APIC_DM_EXTINT | APIC_LVT_MASKED; apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu); } apic_write(APIC_LVT0, value); /* * Only the BSP sees the LINT1 NMI signal by default. This can be * modified by apic_extnmi= boot option. */ if ((!cpu && apic_extnmi != APIC_EXTNMI_NONE) || apic_extnmi == APIC_EXTNMI_ALL) value = APIC_DM_NMI; else value = APIC_DM_NMI | APIC_LVT_MASKED; if (!lapic_is_integrated()) /* 82489DX */ value |= APIC_LVT_LEVEL_TRIGGER; apic_write(APIC_LVT1, value); #ifdef CONFIG_X86_MCE_INTEL /* Recheck CMCI information after local APIC is up on CPU #0 */ if (!cpu) cmci_recheck(); #endif } static void end_local_APIC_setup(void) { lapic_setup_esr(); #ifdef CONFIG_X86_32 { unsigned int value; /* Disable the local apic timer */ value = apic_read(APIC_LVTT); value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); apic_write(APIC_LVTT, value); } #endif apic_pm_activate(); } /* * APIC setup function for application processors. Called from smpboot.c */ void apic_ap_setup(void) { setup_local_APIC(); end_local_APIC_setup(); } #ifdef CONFIG_X86_X2APIC int x2apic_mode; enum { X2APIC_OFF, X2APIC_ON, X2APIC_DISABLED, }; static int x2apic_state; static void __x2apic_disable(void) { u64 msr; if (!boot_cpu_has(X86_FEATURE_APIC)) return; rdmsrl(MSR_IA32_APICBASE, msr); if (!(msr & X2APIC_ENABLE)) return; /* Disable xapic and x2apic first and then reenable xapic mode */ wrmsrl(MSR_IA32_APICBASE, msr & ~(X2APIC_ENABLE | XAPIC_ENABLE)); wrmsrl(MSR_IA32_APICBASE, msr & ~X2APIC_ENABLE); printk_once(KERN_INFO "x2apic disabled\n"); } static void __x2apic_enable(void) { u64 msr; rdmsrl(MSR_IA32_APICBASE, msr); if (msr & X2APIC_ENABLE) return; wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE); printk_once(KERN_INFO "x2apic enabled\n"); } static int __init setup_nox2apic(char *str) { if (x2apic_enabled()) { int apicid = native_apic_msr_read(APIC_ID); if (apicid >= 255) { pr_warning("Apicid: %08x, cannot enforce nox2apic\n", apicid); return 0; } pr_warning("x2apic already enabled.\n"); __x2apic_disable(); } setup_clear_cpu_cap(X86_FEATURE_X2APIC); x2apic_state = X2APIC_DISABLED; x2apic_mode = 0; return 0; } early_param("nox2apic", setup_nox2apic); /* Called from cpu_init() to enable x2apic on (secondary) cpus */ void x2apic_setup(void) { /* * If x2apic is not in ON state, disable it if already enabled * from BIOS. */ if (x2apic_state != X2APIC_ON) { __x2apic_disable(); return; } __x2apic_enable(); } static __init void x2apic_disable(void) { u32 x2apic_id, state = x2apic_state; x2apic_mode = 0; x2apic_state = X2APIC_DISABLED; if (state != X2APIC_ON) return; x2apic_id = read_apic_id(); if (x2apic_id >= 255) panic("Cannot disable x2apic, id: %08x\n", x2apic_id); __x2apic_disable(); register_lapic_address(mp_lapic_addr); } static __init void x2apic_enable(void) { if (x2apic_state != X2APIC_OFF) return; x2apic_mode = 1; x2apic_state = X2APIC_ON; __x2apic_enable(); } static __init void try_to_enable_x2apic(int remap_mode) { if (x2apic_state == X2APIC_DISABLED) return; if (remap_mode != IRQ_REMAP_X2APIC_MODE) { /* IR is required if there is APIC ID > 255 even when running * under KVM */ if (max_physical_apicid > 255 || !hypervisor_x2apic_available()) { pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n"); x2apic_disable(); return; } /* * without IR all CPUs can be addressed by IOAPIC/MSI * only in physical mode */ x2apic_phys = 1; } x2apic_enable(); } void __init check_x2apic(void) { if (x2apic_enabled()) { pr_info("x2apic: enabled by BIOS, switching to x2apic ops\n"); x2apic_mode = 1; x2apic_state = X2APIC_ON; } else if (!boot_cpu_has(X86_FEATURE_X2APIC)) { x2apic_state = X2APIC_DISABLED; } } #else /* CONFIG_X86_X2APIC */ static int __init validate_x2apic(void) { if (!apic_is_x2apic_enabled()) return 0; /* * Checkme: Can we simply turn off x2apic here instead of panic? */ panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n"); } early_initcall(validate_x2apic); static inline void try_to_enable_x2apic(int remap_mode) { } static inline void __x2apic_enable(void) { } #endif /* !CONFIG_X86_X2APIC */ static int __init try_to_enable_IR(void) { #ifdef CONFIG_X86_IO_APIC if (!x2apic_enabled() && skip_ioapic_setup) { pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n"); return -1; } #endif return irq_remapping_enable(); } void __init enable_IR_x2apic(void) { unsigned long flags; int ret, ir_stat; if (skip_ioapic_setup) return; ir_stat = irq_remapping_prepare(); if (ir_stat < 0 && !x2apic_supported()) return; ret = save_ioapic_entries(); if (ret) { pr_info("Saving IO-APIC state failed: %d\n", ret); return; } local_irq_save(flags); legacy_pic->mask_all(); mask_ioapic_entries(); /* If irq_remapping_prepare() succeeded, try to enable it */ if (ir_stat >= 0) ir_stat = try_to_enable_IR(); /* ir_stat contains the remap mode or an error code */ try_to_enable_x2apic(ir_stat); if (ir_stat < 0) restore_ioapic_entries(); legacy_pic->restore_mask(); local_irq_restore(flags); } #ifdef CONFIG_X86_64 /* * Detect and enable local APICs on non-SMP boards. * Original code written by Keir Fraser. * On AMD64 we trust the BIOS - if it says no APIC it is likely * not correctly set up (usually the APIC timer won't work etc.) */ static int __init detect_init_APIC(void) { if (!boot_cpu_has(X86_FEATURE_APIC)) { pr_info("No local APIC present\n"); return -1; } mp_lapic_addr = APIC_DEFAULT_PHYS_BASE; return 0; } #else static int __init apic_verify(void) { u32 features, h, l; /* * The APIC feature bit should now be enabled * in `cpuid' */ features = cpuid_edx(1); if (!(features & (1 << X86_FEATURE_APIC))) { pr_warning("Could not enable APIC!\n"); return -1; } set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); mp_lapic_addr = APIC_DEFAULT_PHYS_BASE; /* The BIOS may have set up the APIC at some other address */ if (boot_cpu_data.x86 >= 6) { rdmsr(MSR_IA32_APICBASE, l, h); if (l & MSR_IA32_APICBASE_ENABLE) mp_lapic_addr = l & MSR_IA32_APICBASE_BASE; } pr_info("Found and enabled local APIC!\n"); return 0; } int __init apic_force_enable(unsigned long addr) { u32 h, l; if (disable_apic) return -1; /* * Some BIOSes disable the local APIC in the APIC_BASE * MSR. This can only be done in software for Intel P6 or later * and AMD K7 (Model > 1) or later. */ if (boot_cpu_data.x86 >= 6) { rdmsr(MSR_IA32_APICBASE, l, h); if (!(l & MSR_IA32_APICBASE_ENABLE)) { pr_info("Local APIC disabled by BIOS -- reenabling.\n"); l &= ~MSR_IA32_APICBASE_BASE; l |= MSR_IA32_APICBASE_ENABLE | addr; wrmsr(MSR_IA32_APICBASE, l, h); enabled_via_apicbase = 1; } } return apic_verify(); } /* * Detect and initialize APIC */ static int __init detect_init_APIC(void) { /* Disabled by kernel option? */ if (disable_apic) return -1; switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) || (boot_cpu_data.x86 >= 15)) break; goto no_apic; case X86_VENDOR_INTEL: if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 || (boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC))) break; goto no_apic; default: goto no_apic; } if (!boot_cpu_has(X86_FEATURE_APIC)) { /* * Over-ride BIOS and try to enable the local APIC only if * "lapic" specified. */ if (!force_enable_local_apic) { pr_info("Local APIC disabled by BIOS -- " "you can enable it with \"lapic\"\n"); return -1; } if (apic_force_enable(APIC_DEFAULT_PHYS_BASE)) return -1; } else { if (apic_verify()) return -1; } apic_pm_activate(); return 0; no_apic: pr_info("No local APIC present or hardware disabled\n"); return -1; } #endif /** * init_apic_mappings - initialize APIC mappings */ void __init init_apic_mappings(void) { unsigned int new_apicid; if (x2apic_mode) { boot_cpu_physical_apicid = read_apic_id(); return; } /* If no local APIC can be found return early */ if (!smp_found_config && detect_init_APIC()) { /* lets NOP'ify apic operations */ pr_info("APIC: disable apic facility\n"); apic_disable(); } else { apic_phys = mp_lapic_addr; /* * acpi lapic path already maps that address in * acpi_register_lapic_address() */ if (!acpi_lapic && !smp_found_config) register_lapic_address(apic_phys); } /* * Fetch the APIC ID of the BSP in case we have a * default configuration (or the MP table is broken). */ new_apicid = read_apic_id(); if (boot_cpu_physical_apicid != new_apicid) { boot_cpu_physical_apicid = new_apicid; /* * yeah -- we lie about apic_version * in case if apic was disabled via boot option * but it's not a problem for SMP compiled kernel * since smp_sanity_check is prepared for such a case * and disable smp mode */ apic_version[new_apicid] = GET_APIC_VERSION(apic_read(APIC_LVR)); } } void __init register_lapic_address(unsigned long address) { mp_lapic_addr = address; if (!x2apic_mode) { set_fixmap_nocache(FIX_APIC_BASE, address); apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n", APIC_BASE, mp_lapic_addr); } if (boot_cpu_physical_apicid == -1U) { boot_cpu_physical_apicid = read_apic_id(); apic_version[boot_cpu_physical_apicid] = GET_APIC_VERSION(apic_read(APIC_LVR)); } } int apic_version[MAX_LOCAL_APIC]; /* * Local APIC interrupts */ /* * This interrupt should _never_ happen with our APIC/SMP architecture */ static void __smp_spurious_interrupt(u8 vector) { u32 v; /* * Check if this really is a spurious interrupt and ACK it * if it is a vectored one. Just in case... * Spurious interrupts should not be ACKed. */ v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1)); if (v & (1 << (vector & 0x1f))) ack_APIC_irq(); inc_irq_stat(irq_spurious_count); /* see sw-dev-man vol 3, chapter 7.4.13.5 */ pr_info("spurious APIC interrupt through vector %02x on CPU#%d, " "should never happen.\n", vector, smp_processor_id()); } __visible void smp_spurious_interrupt(struct pt_regs *regs) { entering_irq(); __smp_spurious_interrupt(~regs->orig_ax); exiting_irq(); } __visible void smp_trace_spurious_interrupt(struct pt_regs *regs) { u8 vector = ~regs->orig_ax; entering_irq(); trace_spurious_apic_entry(vector); __smp_spurious_interrupt(vector); trace_spurious_apic_exit(vector); exiting_irq(); } /* * This interrupt should never happen with our APIC/SMP architecture */ static void __smp_error_interrupt(struct pt_regs *regs) { u32 v; u32 i = 0; static const char * const error_interrupt_reason[] = { "Send CS error", /* APIC Error Bit 0 */ "Receive CS error", /* APIC Error Bit 1 */ "Send accept error", /* APIC Error Bit 2 */ "Receive accept error", /* APIC Error Bit 3 */ "Redirectable IPI", /* APIC Error Bit 4 */ "Send illegal vector", /* APIC Error Bit 5 */ "Received illegal vector", /* APIC Error Bit 6 */ "Illegal register address", /* APIC Error Bit 7 */ }; /* First tickle the hardware, only then report what went on. -- REW */ if (lapic_get_maxlvt() > 3) /* Due to the Pentium erratum 3AP. */ apic_write(APIC_ESR, 0); v = apic_read(APIC_ESR); ack_APIC_irq(); atomic_inc(&irq_err_count); apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x", smp_processor_id(), v); v &= 0xff; while (v) { if (v & 0x1) apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]); i++; v >>= 1; } apic_printk(APIC_DEBUG, KERN_CONT "\n"); } __visible void smp_error_interrupt(struct pt_regs *regs) { entering_irq(); __smp_error_interrupt(regs); exiting_irq(); } __visible void smp_trace_error_interrupt(struct pt_regs *regs) { entering_irq(); trace_error_apic_entry(ERROR_APIC_VECTOR); __smp_error_interrupt(regs); trace_error_apic_exit(ERROR_APIC_VECTOR); exiting_irq(); } /** * connect_bsp_APIC - attach the APIC to the interrupt system */ static void __init connect_bsp_APIC(void) { #ifdef CONFIG_X86_32 if (pic_mode) { /* * Do not trust the local APIC being empty at bootup. */ clear_local_APIC(); /* * PIC mode, enable APIC mode in the IMCR, i.e. connect BSP's * local APIC to INT and NMI lines. */ apic_printk(APIC_VERBOSE, "leaving PIC mode, " "enabling APIC mode.\n"); imcr_pic_to_apic(); } #endif } /** * disconnect_bsp_APIC - detach the APIC from the interrupt system * @virt_wire_setup: indicates, whether virtual wire mode is selected * * Virtual wire mode is necessary to deliver legacy interrupts even when the * APIC is disabled. */ void disconnect_bsp_APIC(int virt_wire_setup) { unsigned int value; #ifdef CONFIG_X86_32 if (pic_mode) { /* * Put the board back into PIC mode (has an effect only on * certain older boards). Note that APIC interrupts, including * IPIs, won't work beyond this point! The only exception are * INIT IPIs. */ apic_printk(APIC_VERBOSE, "disabling APIC mode, " "entering PIC mode.\n"); imcr_apic_to_pic(); return; } #endif /* Go back to Virtual Wire compatibility mode */ /* For the spurious interrupt use vector F, and enable it */ value = apic_read(APIC_SPIV); value &= ~APIC_VECTOR_MASK; value |= APIC_SPIV_APIC_ENABLED; value |= 0xf; apic_write(APIC_SPIV, value); if (!virt_wire_setup) { /* * For LVT0 make it edge triggered, active high, * external and enabled */ value = apic_read(APIC_LVT0); value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING | APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED); value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING; value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT); apic_write(APIC_LVT0, value); } else { /* Disable LVT0 */ apic_write(APIC_LVT0, APIC_LVT_MASKED); } /* * For LVT1 make it edge triggered, active high, * nmi and enabled */ value = apic_read(APIC_LVT1); value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING | APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED); value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING; value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI); apic_write(APIC_LVT1, value); } int generic_processor_info(int apicid, int version) { int cpu, max = nr_cpu_ids; bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid, phys_cpu_present_map); /* * boot_cpu_physical_apicid is designed to have the apicid * returned by read_apic_id(), i.e, the apicid of the * currently booting-up processor. However, on some platforms, * it is temporarily modified by the apicid reported as BSP * through MP table. Concretely: * * - arch/x86/kernel/mpparse.c: MP_processor_info() * - arch/x86/mm/amdtopology.c: amd_numa_init() * * This function is executed with the modified * boot_cpu_physical_apicid. So, disabled_cpu_apicid kernel * parameter doesn't work to disable APs on kdump 2nd kernel. * * Since fixing handling of boot_cpu_physical_apicid requires * another discussion and tests on each platform, we leave it * for now and here we use read_apic_id() directly in this * function, generic_processor_info(). */ if (disabled_cpu_apicid != BAD_APICID && disabled_cpu_apicid != read_apic_id() && disabled_cpu_apicid == apicid) { int thiscpu = num_processors + disabled_cpus; pr_warning("APIC: Disabling requested cpu." " Processor %d/0x%x ignored.\n", thiscpu, apicid); disabled_cpus++; return -ENODEV; } /* * If boot cpu has not been detected yet, then only allow upto * nr_cpu_ids - 1 processors and keep one slot free for boot cpu */ if (!boot_cpu_detected && num_processors >= nr_cpu_ids - 1 && apicid != boot_cpu_physical_apicid) { int thiscpu = max + disabled_cpus - 1; pr_warning( "APIC: NR_CPUS/possible_cpus limit of %i almost" " reached. Keeping one slot for boot cpu." " Processor %d/0x%x ignored.\n", max, thiscpu, apicid); disabled_cpus++; return -ENODEV; } if (num_processors >= nr_cpu_ids) { int thiscpu = max + disabled_cpus; pr_warning( "APIC: NR_CPUS/possible_cpus limit of %i reached." " Processor %d/0x%x ignored.\n", max, thiscpu, apicid); disabled_cpus++; return -EINVAL; } if (apicid == boot_cpu_physical_apicid) { /* * x86_bios_cpu_apicid is required to have processors listed * in same order as logical cpu numbers. Hence the first * entry is BSP, and so on. * boot_cpu_init() already hold bit 0 in cpu_present_mask * for BSP. */ cpu = 0; } else cpu = cpumask_next_zero(-1, cpu_present_mask); /* * This can happen on physical hotplug. The sanity check at boot time * is done from native_smp_prepare_cpus() after num_possible_cpus() is * established. */ if (topology_update_package_map(apicid, cpu) < 0) { int thiscpu = max + disabled_cpus; pr_warning("APIC: Package limit reached. Processor %d/0x%x ignored.\n", thiscpu, apicid); disabled_cpus++; return -ENOSPC; } num_processors++; /* * Validate version */ if (version == 0x0) { pr_warning("BIOS bug: APIC version is 0 for CPU %d/0x%x, fixing up to 0x10\n", cpu, apicid); version = 0x10; } apic_version[apicid] = version; if (version != apic_version[boot_cpu_physical_apicid]) { pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n", apic_version[boot_cpu_physical_apicid], cpu, version); } physid_set(apicid, phys_cpu_present_map); if (apicid > max_physical_apicid) max_physical_apicid = apicid; #if defined(CONFIG_SMP) || defined(CONFIG_X86_64) early_per_cpu(x86_cpu_to_apicid, cpu) = apicid; early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid; #endif #ifdef CONFIG_X86_32 early_per_cpu(x86_cpu_to_logical_apicid, cpu) = apic->x86_32_early_logical_apicid(cpu); #endif set_cpu_possible(cpu, true); set_cpu_present(cpu, true); return cpu; } int hard_smp_processor_id(void) { return read_apic_id(); } void default_init_apic_ldr(void) { unsigned long val; apic_write(APIC_DFR, APIC_DFR_VALUE); val = apic_read(APIC_LDR) & ~APIC_LDR_MASK; val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id()); apic_write(APIC_LDR, val); } int default_cpu_mask_to_apicid_and(const struct cpumask *cpumask, const struct cpumask *andmask, unsigned int *apicid) { unsigned int cpu; for_each_cpu_and(cpu, cpumask, andmask) { if (cpumask_test_cpu(cpu, cpu_online_mask)) break; } if (likely(cpu < nr_cpu_ids)) { *apicid = per_cpu(x86_cpu_to_apicid, cpu); return 0; } return -EINVAL; } /* * Override the generic EOI implementation with an optimized version. * Only called during early boot when only one CPU is active and with * interrupts disabled, so we know this does not race with actual APIC driver * use. */ void __init apic_set_eoi_write(void (*eoi_write)(u32 reg, u32 v)) { struct apic **drv; for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) { /* Should happen once for each apic */ WARN_ON((*drv)->eoi_write == eoi_write); (*drv)->eoi_write = eoi_write; } } static void __init apic_bsp_up_setup(void) { #ifdef CONFIG_X86_64 apic_write(APIC_ID, SET_APIC_ID(boot_cpu_physical_apicid)); #else /* * Hack: In case of kdump, after a crash, kernel might be booting * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid * might be zero if read from MP tables. Get it from LAPIC. */ # ifdef CONFIG_CRASH_DUMP boot_cpu_physical_apicid = read_apic_id(); # endif #endif physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map); } /** * apic_bsp_setup - Setup function for local apic and io-apic * @upmode: Force UP mode (for APIC_init_uniprocessor) * * Returns: * apic_id of BSP APIC */ int __init apic_bsp_setup(bool upmode) { int id; connect_bsp_APIC(); if (upmode) apic_bsp_up_setup(); setup_local_APIC(); if (x2apic_mode) id = apic_read(APIC_LDR); else id = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR)); enable_IO_APIC(); end_local_APIC_setup(); irq_remap_enable_fault_handling(); setup_IO_APIC(); /* Setup local timer */ x86_init.timers.setup_percpu_clockev(); return id; } /* * This initializes the IO-APIC and APIC hardware if this is * a UP kernel. */ int __init APIC_init_uniprocessor(void) { if (disable_apic) { pr_info("Apic disabled\n"); return -1; } #ifdef CONFIG_X86_64 if (!boot_cpu_has(X86_FEATURE_APIC)) { disable_apic = 1; pr_info("Apic disabled by BIOS\n"); return -1; } #else if (!smp_found_config && !boot_cpu_has(X86_FEATURE_APIC)) return -1; /* * Complain if the BIOS pretends there is one. */ if (!boot_cpu_has(X86_FEATURE_APIC) && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) { pr_err("BIOS bug, local APIC 0x%x not detected!...\n", boot_cpu_physical_apicid); return -1; } #endif if (!smp_found_config) disable_ioapic_support(); default_setup_apic_routing(); apic_bsp_setup(true); return 0; } #ifdef CONFIG_UP_LATE_INIT void __init up_late_init(void) { APIC_init_uniprocessor(); } #endif /* * Power management */ #ifdef CONFIG_PM static struct { /* * 'active' is true if the local APIC was enabled by us and * not the BIOS; this signifies that we are also responsible * for disabling it before entering apm/acpi suspend */ int active; /* r/w apic fields */ unsigned int apic_id; unsigned int apic_taskpri; unsigned int apic_ldr; unsigned int apic_dfr; unsigned int apic_spiv; unsigned int apic_lvtt; unsigned int apic_lvtpc; unsigned int apic_lvt0; unsigned int apic_lvt1; unsigned int apic_lvterr; unsigned int apic_tmict; unsigned int apic_tdcr; unsigned int apic_thmr; unsigned int apic_cmci; } apic_pm_state; static int lapic_suspend(void) { unsigned long flags; int maxlvt; if (!apic_pm_state.active) return 0; maxlvt = lapic_get_maxlvt(); apic_pm_state.apic_id = apic_read(APIC_ID); apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI); apic_pm_state.apic_ldr = apic_read(APIC_LDR); apic_pm_state.apic_dfr = apic_read(APIC_DFR); apic_pm_state.apic_spiv = apic_read(APIC_SPIV); apic_pm_state.apic_lvtt = apic_read(APIC_LVTT); if (maxlvt >= 4) apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC); apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0); apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1); apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR); apic_pm_state.apic_tmict = apic_read(APIC_TMICT); apic_pm_state.apic_tdcr = apic_read(APIC_TDCR); #ifdef CONFIG_X86_THERMAL_VECTOR if (maxlvt >= 5) apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR); #endif #ifdef CONFIG_X86_MCE_INTEL if (maxlvt >= 6) apic_pm_state.apic_cmci = apic_read(APIC_LVTCMCI); #endif local_irq_save(flags); disable_local_APIC(); irq_remapping_disable(); local_irq_restore(flags); return 0; } static void lapic_resume(void) { unsigned int l, h; unsigned long flags; int maxlvt; if (!apic_pm_state.active) return; local_irq_save(flags); /* * IO-APIC and PIC have their own resume routines. * We just mask them here to make sure the interrupt * subsystem is completely quiet while we enable x2apic * and interrupt-remapping. */ mask_ioapic_entries(); legacy_pic->mask_all(); if (x2apic_mode) { __x2apic_enable(); } else { /* * Make sure the APICBASE points to the right address * * FIXME! This will be wrong if we ever support suspend on * SMP! We'll need to do this as part of the CPU restore! */ if (boot_cpu_data.x86 >= 6) { rdmsr(MSR_IA32_APICBASE, l, h); l &= ~MSR_IA32_APICBASE_BASE; l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr; wrmsr(MSR_IA32_APICBASE, l, h); } } maxlvt = lapic_get_maxlvt(); apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED); apic_write(APIC_ID, apic_pm_state.apic_id); apic_write(APIC_DFR, apic_pm_state.apic_dfr); apic_write(APIC_LDR, apic_pm_state.apic_ldr); apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri); apic_write(APIC_SPIV, apic_pm_state.apic_spiv); apic_write(APIC_LVT0, apic_pm_state.apic_lvt0); apic_write(APIC_LVT1, apic_pm_state.apic_lvt1); #ifdef CONFIG_X86_THERMAL_VECTOR if (maxlvt >= 5) apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr); #endif #ifdef CONFIG_X86_MCE_INTEL if (maxlvt >= 6) apic_write(APIC_LVTCMCI, apic_pm_state.apic_cmci); #endif if (maxlvt >= 4) apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc); apic_write(APIC_LVTT, apic_pm_state.apic_lvtt); apic_write(APIC_TDCR, apic_pm_state.apic_tdcr); apic_write(APIC_TMICT, apic_pm_state.apic_tmict); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); irq_remapping_reenable(x2apic_mode); local_irq_restore(flags); } /* * This device has no shutdown method - fully functioning local APICs * are needed on every CPU up until machine_halt/restart/poweroff. */ static struct syscore_ops lapic_syscore_ops = { .resume = lapic_resume, .suspend = lapic_suspend, }; static void apic_pm_activate(void) { apic_pm_state.active = 1; } static int __init init_lapic_sysfs(void) { /* XXX: remove suspend/resume procs if !apic_pm_state.active? */ if (boot_cpu_has(X86_FEATURE_APIC)) register_syscore_ops(&lapic_syscore_ops); return 0; } /* local apic needs to resume before other devices access its registers. */ core_initcall(init_lapic_sysfs); #else /* CONFIG_PM */ static void apic_pm_activate(void) { } #endif /* CONFIG_PM */ #ifdef CONFIG_X86_64 static int multi_checked; static int multi; static int set_multi(const struct dmi_system_id *d) { if (multi) return 0; pr_info("APIC: %s detected, Multi Chassis\n", d->ident); multi = 1; return 0; } static const struct dmi_system_id multi_dmi_table[] = { { .callback = set_multi, .ident = "IBM System Summit2", .matches = { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), DMI_MATCH(DMI_PRODUCT_NAME, "Summit2"), }, }, {} }; static void dmi_check_multi(void) { if (multi_checked) return; dmi_check_system(multi_dmi_table); multi_checked = 1; } /* * apic_is_clustered_box() -- Check if we can expect good TSC * * Thus far, the major user of this is IBM's Summit2 series: * Clustered boxes may have unsynced TSC problems if they are * multi-chassis. * Use DMI to check them */ int apic_is_clustered_box(void) { dmi_check_multi(); return multi; } #endif /* * APIC command line parameters */ static int __init setup_disableapic(char *arg) { disable_apic = 1; setup_clear_cpu_cap(X86_FEATURE_APIC); return 0; } early_param("disableapic", setup_disableapic); /* same as disableapic, for compatibility */ static int __init setup_nolapic(char *arg) { return setup_disableapic(arg); } early_param("nolapic", setup_nolapic); static int __init parse_lapic_timer_c2_ok(char *arg) { local_apic_timer_c2_ok = 1; return 0; } early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok); static int __init parse_disable_apic_timer(char *arg) { disable_apic_timer = 1; return 0; } early_param("noapictimer", parse_disable_apic_timer); static int __init parse_nolapic_timer(char *arg) { disable_apic_timer = 1; return 0; } early_param("nolapic_timer", parse_nolapic_timer); static int __init apic_set_verbosity(char *arg) { if (!arg) { #ifdef CONFIG_X86_64 skip_ioapic_setup = 0; return 0; #endif return -EINVAL; } if (strcmp("debug", arg) == 0) apic_verbosity = APIC_DEBUG; else if (strcmp("verbose", arg) == 0) apic_verbosity = APIC_VERBOSE; else { pr_warning("APIC Verbosity level %s not recognised" " use apic=verbose or apic=debug\n", arg); return -EINVAL; } return 0; } early_param("apic", apic_set_verbosity); static int __init lapic_insert_resource(void) { if (!apic_phys) return -1; /* Put local APIC into the resource map. */ lapic_resource.start = apic_phys; lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1; insert_resource(&iomem_resource, &lapic_resource); return 0; } /* * need call insert after e820_reserve_resources() * that is using request_resource */ late_initcall(lapic_insert_resource); static int __init apic_set_disabled_cpu_apicid(char *arg) { if (!arg || !get_option(&arg, &disabled_cpu_apicid)) return -EINVAL; return 0; } early_param("disable_cpu_apicid", apic_set_disabled_cpu_apicid); static int __init apic_set_extnmi(char *arg) { if (!arg) return -EINVAL; if (!strncmp("all", arg, 3)) apic_extnmi = APIC_EXTNMI_ALL; else if (!strncmp("none", arg, 4)) apic_extnmi = APIC_EXTNMI_NONE; else if (!strncmp("bsp", arg, 3)) apic_extnmi = APIC_EXTNMI_BSP; else { pr_warn("Unknown external NMI delivery mode `%s' ignored\n", arg); return -EINVAL; } return 0; } early_param("apic_extnmi", apic_set_extnmi);