/* * Local APIC handling, local APIC timers * * (c) 1999, 2000 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 /* * Sanity check */ #if ((SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F) # error SPURIOUS_APIC_VECTOR definition error #endif /* * Knob to control our willingness to enable the local APIC. * * -1=force-disable, +1=force-enable */ static int enable_local_apic __initdata; /* Local APIC timer verification ok */ static int local_apic_timer_verify_ok; /* Disable local APIC timer from the kernel commandline or via dmi quirk or using CPU MSR check */ int local_apic_timer_disabled; /* Local APIC timer works in C2 */ int local_apic_timer_c2_ok; EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok); /* * Debug level, exported for io_apic.c */ int apic_verbosity; static unsigned int calibration_result; static int lapic_next_event(unsigned long delta, struct clock_event_device *evt); static void lapic_timer_setup(enum clock_event_mode mode, struct clock_event_device *evt); static void lapic_timer_broadcast(cpumask_t mask); static void apic_pm_activate(void); /* * 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_mode = lapic_timer_setup, .set_next_event = lapic_next_event, .broadcast = lapic_timer_broadcast, .rating = 100, .irq = -1, }; static DEFINE_PER_CPU(struct clock_event_device, lapic_events); /* Local APIC was disabled by the BIOS and enabled by the kernel */ static int enabled_via_apicbase; 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) { return APIC_INTEGRATED(lapic_get_version()); } /* * 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; } void apic_wait_icr_idle(void) { while (apic_read(APIC_ICR) & APIC_ICR_BUSY) cpu_relax(); } u32 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; udelay(100); } while (timeout++ < 1000); return send_status; } /** * enable_NMI_through_LVT0 - enable NMI through local vector table 0 */ void __cpuinit enable_NMI_through_LVT0(void) { unsigned int v = APIC_DM_NMI; /* Level triggered for 82489DX */ if (!lapic_is_integrated()) v |= APIC_LVT_LEVEL_TRIGGER; apic_write_around(APIC_LVT0, v); } /** * get_physical_broadcast - Get number of physical broadcast IDs */ int get_physical_broadcast(void) { return modern_apic() ? 0xff : 0xf; } /** * lapic_get_maxlvt - get the maximum number of local vector table entries */ int lapic_get_maxlvt(void) { unsigned int v = apic_read(APIC_LVR); /* 82489DXs do not report # of LVT entries. */ return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2; } /* * Local APIC timer */ /* Clock divisor is set to 16 */ #define APIC_DIVISOR 16 /* * 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; if (!lapic_is_integrated()) lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV); if (!irqen) lvtt_value |= APIC_LVT_MASKED; apic_write_around(APIC_LVTT, lvtt_value); /* * Divide PICLK by 16 */ tmp_value = apic_read(APIC_TDCR); apic_write_around(APIC_TDCR, (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) | APIC_TDR_DIV_16); if (!oneshot) apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR); } /* * Program the next event, relative to now */ static int lapic_next_event(unsigned long delta, struct clock_event_device *evt) { apic_write_around(APIC_TMICT, delta); return 0; } /* * Setup the lapic timer in periodic or oneshot mode */ static void lapic_timer_setup(enum clock_event_mode mode, struct clock_event_device *evt) { unsigned long flags; unsigned int v; /* Lapic used for broadcast ? */ if (!local_apic_timer_verify_ok) return; local_irq_save(flags); switch (mode) { case CLOCK_EVT_MODE_PERIODIC: case CLOCK_EVT_MODE_ONESHOT: __setup_APIC_LVTT(calibration_result, mode != CLOCK_EVT_MODE_PERIODIC, 1); break; case CLOCK_EVT_MODE_UNUSED: case CLOCK_EVT_MODE_SHUTDOWN: v = apic_read(APIC_LVTT); v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); apic_write_around(APIC_LVTT, v); break; case CLOCK_EVT_MODE_RESUME: /* Nothing to do here */ break; } local_irq_restore(flags); } /* * Local APIC timer broadcast function */ static void lapic_timer_broadcast(cpumask_t mask) { #ifdef CONFIG_SMP send_IPI_mask(mask, LOCAL_TIMER_VECTOR); #endif } /* * Setup the local APIC timer for this CPU. Copy the initilized values * of the boot CPU and register the clock event in the framework. */ static void __devinit setup_APIC_timer(void) { struct clock_event_device *levt = &__get_cpu_var(lapic_events); memcpy(levt, &lapic_clockevent, sizeof(*levt)); levt->cpumask = cpumask_of_cpu(smp_processor_id()); clockevents_register_device(levt); } /* * 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 (cpu_has_tsc) rdtscll(tsc); 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; } } /* * Setup the boot APIC * * Calibrate and verify the result. */ void __init setup_boot_APIC_clock(void) { struct clock_event_device *levt = &__get_cpu_var(lapic_events); const long pm_100ms = PMTMR_TICKS_PER_SEC/10; const long pm_thresh = pm_100ms/100; void (*real_handler)(struct clock_event_device *dev); unsigned long deltaj; long delta, deltapm; int pm_referenced = 0; /* * 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 (local_apic_timer_disabled) { /* No broadcast on UP ! */ if (num_possible_cpus() > 1) { lapic_clockevent.mult = 1; setup_APIC_timer(); } return; } 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 1e9. There is no way the lapic * can underflow in the 100ms detection time frame */ __setup_APIC_LVTT(1000000000, 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); /* Check, if the PM timer is available */ deltapm = lapic_cal_pm2 - lapic_cal_pm1; apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm); if (deltapm) { unsigned long mult; u64 res; 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"); } else { res = (((u64) deltapm) * mult) >> 22; do_div(res, 1000000); printk(KERN_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); printk(KERN_INFO "APIC delta adjusted to PM-Timer: " "%lu (%ld)\n", (unsigned long) res, delta); delta = (long) res; } pm_referenced = 1; } /* Calculate the scaled math multiplication factor */ lapic_clockevent.mult = div_sc(delta, TICK_NSEC * LAPIC_CAL_LOOPS, 32); lapic_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFF, &lapic_clockevent); lapic_clockevent.min_delta_ns = clockevent_delta2ns(0xF, &lapic_clockevent); calibration_result = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS; apic_printk(APIC_VERBOSE, "..... delta %ld\n", delta); apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult); apic_printk(APIC_VERBOSE, "..... calibration result: %u\n", calibration_result); if (cpu_has_tsc) { delta = (long)(lapic_cal_tsc2 - lapic_cal_tsc1); apic_printk(APIC_VERBOSE, "..... CPU clock speed is " "%ld.%04ld MHz.\n", (delta / LAPIC_CAL_LOOPS) / (1000000 / HZ), (delta / LAPIC_CAL_LOOPS) % (1000000 / HZ)); } apic_printk(APIC_VERBOSE, "..... host bus clock speed is " "%u.%04u MHz.\n", calibration_result / (1000000 / HZ), calibration_result % (1000000 / HZ)); local_apic_timer_verify_ok = 1; /* * Do a sanity check on the APIC calibration result */ if (calibration_result < (1000000 / HZ)) { local_irq_enable(); printk(KERN_WARNING "APIC frequency too slow, disabling apic timer\n"); /* No broadcast on UP ! */ if (num_possible_cpus() > 1) setup_APIC_timer(); return; } /* We trust the pm 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_setup(CLOCK_EVT_MODE_PERIODIC, levt); lapic_cal_loops = -1; /* Let the interrupts run */ local_irq_enable(); while (lapic_cal_loops <= LAPIC_CAL_LOOPS) cpu_relax(); local_irq_disable(); /* Stop the lapic timer */ lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt); local_irq_enable(); /* 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 local_apic_timer_verify_ok = 0; } else local_irq_enable(); if (!local_apic_timer_verify_ok) { printk(KERN_WARNING "APIC timer disabled due to verification failure.\n"); /* No broadcast on UP ! */ if (num_possible_cpus() == 1) return; } else { /* * If nmi_watchdog is set to IO_APIC, we need the * PIT/HPET going. Otherwise register lapic as a dummy * device. */ if (nmi_watchdog != NMI_IO_APIC) lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY; else printk(KERN_WARNING "APIC timer registered as dummy," " due to nmi_watchdog=1!\n"); } /* Setup the lapic or request the broadcast */ setup_APIC_timer(); } void __devinit 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) { printk(KERN_WARNING "Spurious LAPIC timer interrupt on cpu %d\n", cpu); /* Switch it off */ lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt); return; } /* * the NMI deadlock-detector uses this. */ per_cpu(irq_stat, cpu).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 ... ] */ void 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. */ ack_APIC_irq(); /* * 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. */ irq_enter(); local_apic_timer_interrupt(); irq_exit(); 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 (!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_around(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_around(APIC_LVTT, v | APIC_LVT_MASKED); v = apic_read(APIC_LVT0); apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED); v = apic_read(APIC_LVT1); apic_write_around(APIC_LVT1, v | APIC_LVT_MASKED); if (maxlvt >= 4) { v = apic_read(APIC_LVTPC); apic_write_around(APIC_LVTPC, v | APIC_LVT_MASKED); } /* lets not touch this if we didn't frob it */ #ifdef CONFIG_X86_MCE_P4THERMAL if (maxlvt >= 5) { v = apic_read(APIC_LVTTHMR); apic_write_around(APIC_LVTTHMR, v | APIC_LVT_MASKED); } #endif /* * Clean APIC state for other OSs: */ apic_write_around(APIC_LVTT, APIC_LVT_MASKED); apic_write_around(APIC_LVT0, APIC_LVT_MASKED); apic_write_around(APIC_LVT1, APIC_LVT_MASKED); if (maxlvt >= 3) apic_write_around(APIC_LVTERR, APIC_LVT_MASKED); if (maxlvt >= 4) apic_write_around(APIC_LVTPC, APIC_LVT_MASKED); #ifdef CONFIG_X86_MCE_P4THERMAL if (maxlvt >= 5) apic_write_around(APIC_LVTTHMR, APIC_LVT_MASKED); #endif /* 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 long value; clear_local_APIC(); /* * Disable APIC (implies clearing of registers * for 82489DX!). */ value = apic_read(APIC_SPIV); value &= ~APIC_SPIV_APIC_ENABLED; apic_write_around(APIC_SPIV, value); /* * 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); } } /* * 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 (!cpu_has_apic) return; local_irq_save(flags); clear_local_APIC(); if (enabled_via_apicbase) disable_local_APIC(); local_irq_restore(flags); } /* * This is to verify that we're looking at a real local APIC. * Check these against your board if the CPUs aren't getting * started for no apparent reason. */ int __init verify_local_APIC(void) { unsigned int reg0, reg1; /* * The version register is read-only in a real APIC. */ reg0 = apic_read(APIC_LVR); apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0); apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK); reg1 = apic_read(APIC_LVR); apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1); /* * The two version reads above should print the same * numbers. If the second one is different, then we * poke at a non-APIC. */ if (reg1 != reg0) return 0; /* * Check if the version looks reasonably. */ reg1 = GET_APIC_VERSION(reg0); if (reg1 == 0x00 || reg1 == 0xff) return 0; reg1 = lapic_get_maxlvt(); if (reg1 < 0x02 || reg1 == 0xff) return 0; /* * The ID register is read/write in a real APIC. */ reg0 = apic_read(APIC_ID); apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0); /* * The next two are just to see if we have sane values. * They're only really relevant if we're in Virtual Wire * compatibility mode, but most boxes are anymore. */ reg0 = apic_read(APIC_LVT0); apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0); reg1 = apic_read(APIC_LVT1); apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1); return 1; } /** * 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_around(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 long 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 || !cpu_has_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; /* 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 value |= APIC_SPIV_FOCUS_DISABLED; value |= SPURIOUS_APIC_VECTOR; apic_write_around(APIC_SPIV, value); /* * Set up the virtual wire mode. */ apic_write_around(APIC_LVT0, APIC_DM_EXTINT); value = APIC_DM_NMI; if (!lapic_is_integrated()) /* 82489DX */ value |= APIC_LVT_LEVEL_TRIGGER; apic_write_around(APIC_LVT1, value); } /** * setup_local_APIC - setup the local APIC */ void __cpuinit setup_local_APIC(void) { unsigned long oldvalue, value, maxlvt, integrated; int i, j; /* Pound the ESR really hard over the head with a big hammer - mbligh */ if (esr_disable) { apic_write(APIC_ESR, 0); apic_write(APIC_ESR, 0); apic_write(APIC_ESR, 0); apic_write(APIC_ESR, 0); } integrated = lapic_is_integrated(); /* * Double-check whether this APIC is really registered. */ if (!apic_id_registered()) BUG(); /* * 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... */ init_apic_ldr(); /* * Set Task Priority to 'accept all'. We never change this * later on. */ value = apic_read(APIC_TASKPRI); value &= ~APIC_TPRI_MASK; apic_write_around(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. */ 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< 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_around(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%08lx after: 0x%08lx\n", oldvalue, value); } else { if (esr_disable) /* * 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 */ printk(KERN_INFO "Leaving ESR disabled.\n"); else printk(KERN_INFO "No ESR for 82489DX.\n"); } /* Disable the local apic timer */ value = apic_read(APIC_LVTT); value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR); apic_write_around(APIC_LVTT, value); setup_apic_nmi_watchdog(NULL); apic_pm_activate(); } /* * Detect and initialize APIC */ static int __init detect_init_APIC(void) { u32 h, l, features; /* Disabled by kernel option? */ if (enable_local_apic < 0) 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 && cpu_has_apic)) break; goto no_apic; default: goto no_apic; } if (!cpu_has_apic) { /* * Over-ride BIOS and try to enable the local APIC only if * "lapic" specified. */ if (enable_local_apic <= 0) { printk(KERN_INFO "Local APIC disabled by BIOS -- " "you can enable it with \"lapic\"\n"); 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. */ rdmsr(MSR_IA32_APICBASE, l, h); if (!(l & MSR_IA32_APICBASE_ENABLE)) { printk(KERN_INFO "Local APIC disabled by BIOS -- reenabling.\n"); l &= ~MSR_IA32_APICBASE_BASE; l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE; wrmsr(MSR_IA32_APICBASE, l, h); enabled_via_apicbase = 1; } } /* * The APIC feature bit should now be enabled * in `cpuid' */ features = cpuid_edx(1); if (!(features & (1 << X86_FEATURE_APIC))) { printk(KERN_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 */ rdmsr(MSR_IA32_APICBASE, l, h); if (l & MSR_IA32_APICBASE_ENABLE) mp_lapic_addr = l & MSR_IA32_APICBASE_BASE; if (nmi_watchdog != NMI_NONE && nmi_watchdog != NMI_DISABLED) nmi_watchdog = NMI_LOCAL_APIC; printk(KERN_INFO "Found and enabled local APIC!\n"); apic_pm_activate(); return 0; no_apic: printk(KERN_INFO "No local APIC present or hardware disabled\n"); return -1; } /** * init_apic_mappings - initialize APIC mappings */ void __init init_apic_mappings(void) { /* * If no local APIC can be found then set up a fake all * zeroes page to simulate the local APIC and another * one for the IO-APIC. */ if (!smp_found_config && detect_init_APIC()) { apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); apic_phys = __pa(apic_phys); } else apic_phys = mp_lapic_addr; set_fixmap_nocache(FIX_APIC_BASE, apic_phys); printk(KERN_DEBUG "mapped APIC to %08lx (%08lx)\n", APIC_BASE, apic_phys); /* * Fetch the APIC ID of the BSP in case we have a * default configuration (or the MP table is broken). */ if (boot_cpu_physical_apicid == -1U) boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID)); #ifdef CONFIG_X86_IO_APIC { unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0; int i; for (i = 0; i < nr_ioapics; i++) { if (smp_found_config) { ioapic_phys = mp_ioapics[i].mpc_apicaddr; if (!ioapic_phys) { printk(KERN_ERR "WARNING: bogus zero IO-APIC " "address found in MPTABLE, " "disabling IO/APIC support!\n"); smp_found_config = 0; skip_ioapic_setup = 1; goto fake_ioapic_page; } } else { fake_ioapic_page: ioapic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE); ioapic_phys = __pa(ioapic_phys); } set_fixmap_nocache(idx, ioapic_phys); printk(KERN_DEBUG "mapped IOAPIC to %08lx (%08lx)\n", __fix_to_virt(idx), ioapic_phys); idx++; } } #endif } /* * This initializes the IO-APIC and APIC hardware if this is * a UP kernel. */ int __init APIC_init_uniprocessor(void) { if (enable_local_apic < 0) clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); if (!smp_found_config && !cpu_has_apic) return -1; /* * Complain if the BIOS pretends there is one. */ if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) { printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n", boot_cpu_physical_apicid); clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); return -1; } verify_local_APIC(); connect_bsp_APIC(); /* * 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 = GET_APIC_ID(apic_read(APIC_ID)); #endif phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid); setup_local_APIC(); #ifdef CONFIG_X86_IO_APIC if (smp_found_config) if (!skip_ioapic_setup && nr_ioapics) setup_IO_APIC(); #endif setup_boot_clock(); return 0; } /* * Local APIC interrupts */ /* * This interrupt should _never_ happen with our APIC/SMP architecture */ void smp_spurious_interrupt(struct pt_regs *regs) { unsigned long v; irq_enter(); /* * 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 + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1)); if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f))) ack_APIC_irq(); /* see sw-dev-man vol 3, chapter 7.4.13.5 */ printk(KERN_INFO "spurious APIC interrupt on CPU#%d, " "should never happen.\n", smp_processor_id()); __get_cpu_var(irq_stat).irq_spurious_count++; irq_exit(); } /* * This interrupt should never happen with our APIC/SMP architecture */ void smp_error_interrupt(struct pt_regs *regs) { unsigned long v, v1; irq_enter(); /* First tickle the hardware, only then report what went on. -- REW */ v = apic_read(APIC_ESR); apic_write(APIC_ESR, 0); v1 = apic_read(APIC_ESR); ack_APIC_irq(); atomic_inc(&irq_err_count); /* Here is what the APIC error bits mean: 0: Send CS error 1: Receive CS error 2: Send accept error 3: Receive accept error 4: Reserved 5: Send illegal vector 6: Received illegal vector 7: Illegal register address */ printk(KERN_DEBUG "APIC error on CPU%d: %02lx(%02lx)\n", smp_processor_id(), v , v1); irq_exit(); } /* * Initialize APIC interrupts */ void __init apic_intr_init(void) { #ifdef CONFIG_SMP smp_intr_init(); #endif /* self generated IPI for local APIC timer */ set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt); /* IPI vectors for APIC spurious and error interrupts */ set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt); set_intr_gate(ERROR_APIC_VECTOR, error_interrupt); /* thermal monitor LVT interrupt */ #ifdef CONFIG_X86_MCE_P4THERMAL set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt); #endif } /** * connect_bsp_APIC - attach the APIC to the interrupt system */ void __init connect_bsp_APIC(void) { 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"); outb(0x70, 0x22); outb(0x01, 0x23); } enable_apic_mode(); } /** * 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) { 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"); outb(0x70, 0x22); outb(0x00, 0x23); } else { /* Go back to Virtual Wire compatibility mode */ unsigned long value; /* 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_around(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_around(APIC_LVT0, value); } else { /* Disable LVT0 */ apic_write_around(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_around(APIC_LVT1, value); } } /* * Power management */ #ifdef CONFIG_PM static struct { 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; } apic_pm_state; static int lapic_suspend(struct sys_device *dev, pm_message_t state) { 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_MCE_P4THERMAL if (maxlvt >= 5) apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR); #endif local_irq_save(flags); disable_local_APIC(); local_irq_restore(flags); return 0; } static int lapic_resume(struct sys_device *dev) { unsigned int l, h; unsigned long flags; int maxlvt; if (!apic_pm_state.active) return 0; maxlvt = lapic_get_maxlvt(); local_irq_save(flags); /* * 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! */ 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); 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_MCE_P4THERMAL if (maxlvt >= 5) apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr); #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); local_irq_restore(flags); return 0; } /* * This device has no shutdown method - fully functioning local APICs * are needed on every CPU up until machine_halt/restart/poweroff. */ static struct sysdev_class lapic_sysclass = { .name = "lapic", .resume = lapic_resume, .suspend = lapic_suspend, }; static struct sys_device device_lapic = { .id = 0, .cls = &lapic_sysclass, }; static void __devinit apic_pm_activate(void) { apic_pm_state.active = 1; } static int __init init_lapic_sysfs(void) { int error; if (!cpu_has_apic) return 0; /* XXX: remove suspend/resume procs if !apic_pm_state.active? */ error = sysdev_class_register(&lapic_sysclass); if (!error) error = sysdev_register(&device_lapic); return error; } device_initcall(init_lapic_sysfs); #else /* CONFIG_PM */ static void apic_pm_activate(void) { } #endif /* CONFIG_PM */ /* * APIC command line parameters */ static int __init parse_lapic(char *arg) { enable_local_apic = 1; return 0; } early_param("lapic", parse_lapic); static int __init parse_nolapic(char *arg) { enable_local_apic = -1; clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); return 0; } early_param("nolapic", parse_nolapic); static int __init parse_disable_lapic_timer(char *arg) { local_apic_timer_disabled = 1; return 0; } early_param("nolapic_timer", parse_disable_lapic_timer); 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 apic_set_verbosity(char *str) { if (strcmp("debug", str) == 0) apic_verbosity = APIC_DEBUG; else if (strcmp("verbose", str) == 0) apic_verbosity = APIC_VERBOSE; return 1; } __setup("apic=", apic_set_verbosity);