v4.19.13 snapshot.
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
new file mode 100644
index 0000000..84132ed
--- /dev/null
+++ b/arch/x86/kernel/apic/apic.c
@@ -0,0 +1,2766 @@
+/*
+ * Local APIC handling, local APIC timers
+ *
+ * (c) 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
+ *
+ * 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 <linux/perf_event.h>
+#include <linux/kernel_stat.h>
+#include <linux/mc146818rtc.h>
+#include <linux/acpi_pmtmr.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/bootmem.h>
+#include <linux/ftrace.h>
+#include <linux/ioport.h>
+#include <linux/export.h>
+#include <linux/syscore_ops.h>
+#include <linux/delay.h>
+#include <linux/timex.h>
+#include <linux/i8253.h>
+#include <linux/dmar.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/dmi.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+
+#include <asm/trace/irq_vectors.h>
+#include <asm/irq_remapping.h>
+#include <asm/perf_event.h>
+#include <asm/x86_init.h>
+#include <asm/pgalloc.h>
+#include <linux/atomic.h>
+#include <asm/mpspec.h>
+#include <asm/i8259.h>
+#include <asm/proto.h>
+#include <asm/apic.h>
+#include <asm/io_apic.h>
+#include <asm/desc.h>
+#include <asm/hpet.h>
+#include <asm/mtrr.h>
+#include <asm/time.h>
+#include <asm/smp.h>
+#include <asm/mce.h>
+#include <asm/tsc.h>
+#include <asm/hypervisor.h>
+#include <asm/cpu_device_id.h>
+#include <asm/intel-family.h>
+#include <asm/irq_regs.h>
+
+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);
+
+u8 boot_cpu_apic_version;
+
+/*
+ * 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=<int>, 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);
+
+/*
+ * 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)
+{
+ 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;
+}
+
+/*
+ * 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)
+{
+ /*
+ * - we always have APIC integrated on 64bit mode
+ * - 82489DXs do not report # of LVT entries
+ */
+ return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 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_state_oneshot_stopped = lapic_timer_shutdown,
+ .set_next_event = lapic_next_event,
+ .broadcast = lapic_timer_broadcast,
+ .rating = 100,
+ .irq = -1,
+};
+static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
+
+#define DEADLINE_MODEL_MATCH_FUNC(model, func) \
+ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)&func }
+
+#define DEADLINE_MODEL_MATCH_REV(model, rev) \
+ { X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, (unsigned long)rev }
+
+static u32 hsx_deadline_rev(void)
+{
+ switch (boot_cpu_data.x86_stepping) {
+ case 0x02: return 0x3a; /* EP */
+ case 0x04: return 0x0f; /* EX */
+ }
+
+ return ~0U;
+}
+
+static u32 bdx_deadline_rev(void)
+{
+ switch (boot_cpu_data.x86_stepping) {
+ case 0x02: return 0x00000011;
+ case 0x03: return 0x0700000e;
+ case 0x04: return 0x0f00000c;
+ case 0x05: return 0x0e000003;
+ }
+
+ return ~0U;
+}
+
+static u32 skx_deadline_rev(void)
+{
+ switch (boot_cpu_data.x86_stepping) {
+ case 0x03: return 0x01000136;
+ case 0x04: return 0x02000014;
+ }
+
+ if (boot_cpu_data.x86_stepping > 4)
+ return 0;
+
+ return ~0U;
+}
+
+static const struct x86_cpu_id deadline_match[] = {
+ DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_HASWELL_X, hsx_deadline_rev),
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_X, 0x0b000020),
+ DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_BROADWELL_XEON_D, bdx_deadline_rev),
+ DEADLINE_MODEL_MATCH_FUNC( INTEL_FAM6_SKYLAKE_X, skx_deadline_rev),
+
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_CORE, 0x22),
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_ULT, 0x20),
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_HASWELL_GT3E, 0x17),
+
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_CORE, 0x25),
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_BROADWELL_GT3E, 0x17),
+
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_MOBILE, 0xb2),
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_SKYLAKE_DESKTOP, 0xb2),
+
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_MOBILE, 0x52),
+ DEADLINE_MODEL_MATCH_REV ( INTEL_FAM6_KABYLAKE_DESKTOP, 0x52),
+
+ {},
+};
+
+static void apic_check_deadline_errata(void)
+{
+ const struct x86_cpu_id *m;
+ u32 rev;
+
+ if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER) ||
+ boot_cpu_has(X86_FEATURE_HYPERVISOR))
+ return;
+
+ m = x86_match_cpu(deadline_match);
+ if (!m)
+ return;
+
+ /*
+ * Function pointers will have the MSB set due to address layout,
+ * immediate revisions will not.
+ */
+ if ((long)m->driver_data < 0)
+ rev = ((u32 (*)(void))(m->driver_data))();
+ else
+ rev = (u32)m->driver_data;
+
+ if (boot_cpu_data.microcode >= rev)
+ return;
+
+ setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
+ pr_err(FW_BUG "TSC_DEADLINE disabled due to Errata; "
+ "please update microcode to version: 0x%x (or later)\n", rev);
+}
+
+/*
+ * 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->name = "lapic-deadline";
+ 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.max_delta_ticks = 0x7FFFFF;
+ lapic_clockevent.min_delta_ns =
+ clockevent_delta2ns(0xF, &lapic_clockevent);
+ lapic_clockevent.min_delta_ticks = 0xF;
+ 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.max_delta_ticks = 0x7FFFFFFF;
+ lapic_clockevent.min_delta_ns =
+ clockevent_delta2ns(0xF, &lapic_clockevent);
+ lapic_clockevent.min_delta_ticks = 0xF;
+
+ 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();
+ amd_e400_c1e_apic_setup();
+}
+
+void setup_secondary_APIC_clock(void)
+{
+ setup_APIC_timer();
+ amd_e400_c1e_apic_setup();
+}
+
+/*
+ * The guts of the apic timer interrupt
+ */
+static void local_apic_timer_interrupt(void)
+{
+ struct clock_event_device *evt = this_cpu_ptr(&lapic_events);
+
+ /*
+ * 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",
+ smp_processor_id());
+ /* 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();
+ 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);
+}
+
+enum apic_intr_mode_id apic_intr_mode;
+
+static int __init apic_intr_mode_select(void)
+{
+ /* Check kernel option */
+ if (disable_apic) {
+ pr_info("APIC disabled via kernel command line\n");
+ return APIC_PIC;
+ }
+
+ /* Check BIOS */
+#ifdef CONFIG_X86_64
+ /* On 64-bit, the APIC must be integrated, Check local APIC only */
+ if (!boot_cpu_has(X86_FEATURE_APIC)) {
+ disable_apic = 1;
+ pr_info("APIC disabled by BIOS\n");
+ return APIC_PIC;
+ }
+#else
+ /* On 32-bit, the APIC may be integrated APIC or 82489DX */
+
+ /* Neither 82489DX nor integrated APIC ? */
+ if (!boot_cpu_has(X86_FEATURE_APIC) && !smp_found_config) {
+ disable_apic = 1;
+ return APIC_PIC;
+ }
+
+ /* If the BIOS pretends there is an integrated APIC ? */
+ if (!boot_cpu_has(X86_FEATURE_APIC) &&
+ APIC_INTEGRATED(boot_cpu_apic_version)) {
+ disable_apic = 1;
+ pr_err(FW_BUG "Local APIC %d not detected, force emulation\n",
+ boot_cpu_physical_apicid);
+ return APIC_PIC;
+ }
+#endif
+
+ /* Check MP table or ACPI MADT configuration */
+ if (!smp_found_config) {
+ disable_ioapic_support();
+ if (!acpi_lapic) {
+ pr_info("APIC: ACPI MADT or MP tables are not detected\n");
+ return APIC_VIRTUAL_WIRE_NO_CONFIG;
+ }
+ return APIC_VIRTUAL_WIRE;
+ }
+
+#ifdef CONFIG_SMP
+ /* If SMP should be disabled, then really disable it! */
+ if (!setup_max_cpus) {
+ pr_info("APIC: SMP mode deactivated\n");
+ return APIC_SYMMETRIC_IO_NO_ROUTING;
+ }
+
+ if (read_apic_id() != boot_cpu_physical_apicid) {
+ panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
+ read_apic_id(), boot_cpu_physical_apicid);
+ /* Or can we switch back to PIC here? */
+ }
+#endif
+
+ return APIC_SYMMETRIC_IO;
+}
+
+/*
+ * 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);
+}
+
+/* Init the interrupt delivery mode for the BSP */
+void __init apic_intr_mode_init(void)
+{
+ bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
+
+ apic_intr_mode = apic_intr_mode_select();
+
+ switch (apic_intr_mode) {
+ case APIC_PIC:
+ pr_info("APIC: Keep in PIC mode(8259)\n");
+ return;
+ case APIC_VIRTUAL_WIRE:
+ pr_info("APIC: Switch to virtual wire mode setup\n");
+ default_setup_apic_routing();
+ break;
+ case APIC_VIRTUAL_WIRE_NO_CONFIG:
+ pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
+ upmode = true;
+ default_setup_apic_routing();
+ break;
+ case APIC_SYMMETRIC_IO:
+ pr_info("APIC: Switch to symmetric I/O mode setup\n");
+ default_setup_apic_routing();
+ break;
+ case APIC_SYMMETRIC_IO_NO_ROUTING:
+ pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
+ break;
+ }
+
+ apic_bsp_setup(upmode);
+}
+
+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);
+}
+
+static void apic_pending_intr_clear(void)
+{
+ long long max_loops = cpu_khz ? cpu_khz : 1000000;
+ unsigned long long tsc = 0, ntsc;
+ unsigned int queued;
+ unsigned long value;
+ int i, j, acked = 0;
+
+ if (boot_cpu_has(X86_FEATURE_TSC))
+ tsc = rdtsc();
+ /*
+ * 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_each_set_bit(j, &value, 32) {
+ ack_APIC_irq();
+ acked++;
+ }
+ }
+ if (acked > 256) {
+ pr_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);
+}
+
+/**
+ * setup_local_APIC - setup the local APIC
+ *
+ * Used to setup local APIC while initializing BSP or bringing up APs.
+ * Always called with preemption disabled.
+ */
+static void setup_local_APIC(void)
+{
+ int cpu = smp_processor_id();
+ unsigned int value;
+#ifdef CONFIG_X86_32
+ int logical_apicid, ldr_apicid;
+#endif
+
+
+ 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.
+ */
+ logical_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
+ ldr_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
+ WARN_ON(logical_apicid != BAD_APICID && logical_apicid != ldr_apicid);
+ /* always use the value from LDR */
+ early_per_cpu(x86_cpu_to_logical_apicid, cpu) = ldr_apicid;
+#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);
+
+ apic_pending_intr_clear();
+
+ /*
+ * 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).
+ */
+
+ /*
+ * - 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 boot CPU'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 || skip_ioapic_setup)) {
+ 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;
+
+ /* Is 82489DX ? */
+ if (!lapic_is_integrated())
+ 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 ||
+ !x86_init.hyper.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 */
+
+void __init enable_IR_x2apic(void)
+{
+ unsigned long flags;
+ int ret, ir_stat;
+
+ if (skip_ioapic_setup) {
+ pr_info("Not enabling interrupt remapping due to skipped IO-APIC setup\n");
+ 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 = irq_remapping_enable();
+ /* 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;
+
+ apic_check_deadline_errata();
+
+ 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;
+
+ /*
+ * If the system has ACPI MADT tables or MP info, the LAPIC
+ * address is already registered.
+ */
+ 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 apic_intr_mode_select is prepared for such
+ * a case and disable smp mode
+ */
+ boot_cpu_apic_version = 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, address);
+ }
+ if (boot_cpu_physical_apicid == -1U) {
+ boot_cpu_physical_apicid = read_apic_id();
+ boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
+ }
+}
+
+/*
+ * Local APIC interrupts
+ */
+
+/*
+ * This interrupt should _never_ happen with our APIC/SMP architecture
+ */
+__visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
+{
+ u8 vector = ~regs->orig_ax;
+ u32 v;
+
+ entering_irq();
+ trace_spurious_apic_entry(vector);
+
+ /*
+ * 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());
+
+ trace_spurious_apic_exit(vector);
+ exiting_irq();
+}
+
+/*
+ * This interrupt should never happen with our APIC/SMP architecture
+ */
+__visible void __irq_entry smp_error_interrupt(struct pt_regs *regs)
+{
+ 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 */
+ };
+ u32 v, i = 0;
+
+ entering_irq();
+ trace_error_apic_entry(ERROR_APIC_VECTOR);
+
+ /* 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");
+
+ 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);
+}
+
+/*
+ * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
+ * contiguously, it equals to current allocated max logical CPU ID plus 1.
+ * All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
+ * so the maximum of nr_logical_cpuids is nr_cpu_ids.
+ *
+ * NOTE: Reserve 0 for BSP.
+ */
+static int nr_logical_cpuids = 1;
+
+/*
+ * Used to store mapping between logical CPU IDs and APIC IDs.
+ */
+static int cpuid_to_apicid[] = {
+ [0 ... NR_CPUS - 1] = -1,
+};
+
+#ifdef CONFIG_SMP
+/**
+ * apic_id_is_primary_thread - Check whether APIC ID belongs to a primary thread
+ * @id: APIC ID to check
+ */
+bool apic_id_is_primary_thread(unsigned int apicid)
+{
+ u32 mask;
+
+ if (smp_num_siblings == 1)
+ return true;
+ /* Isolate the SMT bit(s) in the APICID and check for 0 */
+ mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
+ return !(apicid & mask);
+}
+#endif
+
+/*
+ * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
+ * and cpuid_to_apicid[] synchronized.
+ */
+static int allocate_logical_cpuid(int apicid)
+{
+ int i;
+
+ /*
+ * cpuid <-> apicid mapping is persistent, so when a cpu is up,
+ * check if the kernel has allocated a cpuid for it.
+ */
+ for (i = 0; i < nr_logical_cpuids; i++) {
+ if (cpuid_to_apicid[i] == apicid)
+ return i;
+ }
+
+ /* Allocate a new cpuid. */
+ if (nr_logical_cpuids >= nr_cpu_ids) {
+ WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
+ "Processor %d/0x%x and the rest are ignored.\n",
+ nr_cpu_ids, nr_logical_cpuids, apicid);
+ return -EINVAL;
+ }
+
+ cpuid_to_apicid[nr_logical_cpuids] = apicid;
+ return nr_logical_cpuids++;
+}
+
+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;
+
+ /* Logical cpuid 0 is reserved for BSP. */
+ cpuid_to_apicid[0] = apicid;
+ } else {
+ cpu = allocate_logical_cpuid(apicid);
+ if (cpu < 0) {
+ disabled_cpus++;
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * 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;
+ }
+
+ if (version != boot_cpu_apic_version) {
+ pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",
+ boot_cpu_apic_version, cpu, version);
+ }
+
+ 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);
+ physid_set(apicid, phys_cpu_present_map);
+ set_cpu_present(cpu, true);
+ num_processors++;
+
+ return cpu;
+}
+
+int hard_smp_processor_id(void)
+{
+ return read_apic_id();
+}
+
+/*
+ * 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)->native_eoi_write = (*drv)->eoi_write;
+ (*drv)->eoi_write = eoi_write;
+ }
+}
+
+static void __init apic_bsp_up_setup(void)
+{
+#ifdef CONFIG_X86_64
+ apic_write(APIC_ID, apic->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
+ */
+void __init apic_bsp_setup(bool upmode)
+{
+ connect_bsp_APIC();
+ if (upmode)
+ apic_bsp_up_setup();
+ setup_local_APIC();
+
+ enable_IO_APIC();
+ end_local_APIC_setup();
+ irq_remap_enable_fault_handling();
+ setup_IO_APIC();
+}
+
+#ifdef CONFIG_UP_LATE_INIT
+void __init up_late_init(void)
+{
+ if (apic_intr_mode == APIC_PIC)
+ return;
+
+ /* Setup local timer */
+ x86_init.timers.setup_percpu_clockev();
+}
+#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;
+#ifdef CONFIG_X86_64
+ else {
+ pr_warning("APIC Verbosity level %s not recognised"
+ " use apic=verbose or apic=debug\n", arg);
+ return -EINVAL;
+ }
+#endif
+
+ 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);