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linux-zen-desktop/arch/x86/kernel/apic/apic.c

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Initial commit
2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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/memblock.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/pc-conf-reg.h>
#include <asm/perf_event.h>
#include <asm/x86_init.h>
#include <linux/atomic.h>
#include <asm/barrier.h>
#include <asm/mpspec.h>
#include <asm/i8259.h>
#include <asm/proto.h>
#include <asm/traps.h>
#include <asm/apic.h>
#include <asm/acpi.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>
#include <asm/cpu.h>
unsigned int num_processors;
unsigned disabled_cpus;
/* Processor that is doing the boot up */
unsigned int boot_cpu_physical_apicid __ro_after_init = -1U;
EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
u8 boot_cpu_apic_version __ro_after_init;
/*
* 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 __ro_after_init = BAD_APICID;
/*
* This variable controls which CPUs receive external NMIs. By default,
* external NMIs are delivered only to the BSP.
*/
static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;
/*
* Hypervisor supports 15 bits of APIC ID in MSI Extended Destination ID
*/
static bool virt_ext_dest_id __ro_after_init;
6.5.5
2023-10-24 12:59:35 +02:00
/* For parallel bootup. */
unsigned long apic_mmio_base __ro_after_init;
Initial commit
2023-08-30 17:31:07 +02:00
/*
* 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 __ro_after_init;
/*
* 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)
{
/* NMI and 8259 INTR go through APIC */
pc_conf_set(PC_CONF_MPS_IMCR, 0x01);
}
static inline void imcr_apic_to_pic(void)
{
/* NMI and 8259 INTR go directly to BSP */
pc_conf_set(PC_CONF_MPS_IMCR, 0x00);
}
#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 1;
}
__setup("apicpmtimer", setup_apicpmtimer);
#endif
unsigned long mp_lapic_addr __ro_after_init;
int disable_apic __ro_after_init;
/* 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 __ro_after_init;
EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
/*
* Debug level, exported for io_apic.c
*/
int apic_verbosity __ro_after_init;
int pic_mode __ro_after_init;
/* Have we found an MP table */
int smp_found_config __ro_after_init;
static struct resource lapic_resource = {
.name = "Local APIC",
.flags = IORESOURCE_MEM | IORESOURCE_BUSY,
};
unsigned int lapic_timer_period = 0;
static void apic_pm_activate(void);
static unsigned long apic_phys __ro_after_init;
/*
* 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;
/* Hygon systems use modern APIC */
if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
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_XAPIC_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
/* i82489DX specific */
#define I82489DX_BASE_DIVIDER (((0x2) << 18))
/*
* 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;
/*
* The i82489DX APIC uses bit 18 and 19 for the base divider. This
* overlaps with bit 18 on integrated APICs, but is not documented
* in the SDM. No problem though. i82489DX equipped systems do not
* have TSC deadline timer.
*/
if (!lapic_is_integrated())
lvtt_value |= I82489DX_BASE_DIVIDER;
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");
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;
} while (!atomic_try_cmpxchg(&eilvt_offsets[offset], &rsvd, new));
rsvd = new & ~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;
/* This MSR is special and need a special fence: */
weak_wrmsr_fence();
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_period, 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);
static const struct x86_cpu_id deadline_match[] __initconst = {
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x2, 0x2), 0x3a), /* EP */
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(HASWELL_X, X86_STEPPINGS(0x4, 0x4), 0x0f), /* EX */
X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_X, 0x0b000020),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x2, 0x2), 0x00000011),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x3, 0x3), 0x0700000e),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x4, 0x4), 0x0f00000c),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x5, 0x5), 0x0e000003),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x3, 0x3), 0x01000136),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x4, 0x4), 0x02000014),
X86_MATCH_INTEL_FAM6_MODEL_STEPPINGS(SKYLAKE_X, X86_STEPPINGS(0x5, 0xf), 0),
X86_MATCH_INTEL_FAM6_MODEL( HASWELL, 0x22),
X86_MATCH_INTEL_FAM6_MODEL( HASWELL_L, 0x20),
X86_MATCH_INTEL_FAM6_MODEL( HASWELL_G, 0x17),
X86_MATCH_INTEL_FAM6_MODEL( BROADWELL, 0x25),
X86_MATCH_INTEL_FAM6_MODEL( BROADWELL_G, 0x17),
X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE_L, 0xb2),
X86_MATCH_INTEL_FAM6_MODEL( SKYLAKE, 0xb2),
X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE_L, 0x52),
X86_MATCH_INTEL_FAM6_MODEL( KABYLAKE, 0x52),
{},
};
static __init bool apic_validate_deadline_timer(void)
{
const struct x86_cpu_id *m;
u32 rev;
if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
return false;
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
return true;
m = x86_match_cpu(deadline_match);
if (!m)
return true;
rev = (u32)m->driver_data;
if (boot_cpu_data.microcode >= rev)
return true;
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);
return false;
}
/*
* 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 preferable 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 synchronous. 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 and polled calibration function.
*/
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_warn("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 lapic_init_clockevent(void)
{
if (!lapic_timer_period)
return -1;
/* Calculate the scaled math multiplication factor */
lapic_clockevent.mult = div_sc(lapic_timer_period/APIC_DIVISOR,
TICK_NSEC, 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;
return 0;
}
bool __init apic_needs_pit(void)
{
/*
* If the frequencies are not known, PIT is required for both TSC
* and apic timer calibration.
*/
if (!tsc_khz || !cpu_khz)
return true;
/* Is there an APIC at all or is it disabled? */
if (!boot_cpu_has(X86_FEATURE_APIC) || disable_apic)
return true;
/*
* If interrupt delivery mode is legacy PIC or virtual wire without
* configuration, the local APIC timer wont be set up. Make sure
* that the PIT is initialized.
*/
if (apic_intr_mode == APIC_PIC ||
apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG)
return true;
/* Virt guests may lack ARAT, but still have DEADLINE */
if (!boot_cpu_has(X86_FEATURE_ARAT))
return true;
/* Deadline timer is based on TSC so no further PIT action required */
if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
return false;
/* APIC timer disabled? */
if (disable_apic_timer)
return true;
/*
* The APIC timer frequency is known already, no PIT calibration
* required. If unknown, let the PIT be initialized.
*/
return lapic_timer_period == 0;
}
static int __init calibrate_APIC_clock(void)
{
struct clock_event_device *levt = this_cpu_ptr(&lapic_events);
u64 tsc_perj = 0, tsc_start = 0;
unsigned long jif_start;
unsigned long deltaj;
long delta, deltatsc;
int pm_referenced = 0;
if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER))
return 0;
/*
* Check if lapic timer has already been calibrated by platform
* specific routine, such as tsc calibration code. If so just fill
* in the clockevent structure and return.
*/
if (!lapic_init_clockevent()) {
apic_printk(APIC_VERBOSE, "lapic timer already calibrated %d\n",
lapic_timer_period);
/*
* Direct calibration methods must have an always running
* local APIC timer, no need for broadcast timer.
*/
lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
return 0;
}
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
"calibrating APIC timer ...\n");
/*
* There are platforms w/o global clockevent devices. Instead of
* making the calibration conditional on that, use a polling based
* approach everywhere.
*/
local_irq_disable();
/*
* 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);
/*
* Methods to terminate the calibration loop:
* 1) Global clockevent if available (jiffies)
* 2) TSC if available and frequency is known
*/
jif_start = READ_ONCE(jiffies);
if (tsc_khz) {
tsc_start = rdtsc();
tsc_perj = div_u64((u64)tsc_khz * 1000, HZ);
}
/*
* Enable interrupts so the tick can fire, if a global
* clockevent device is available
*/
local_irq_enable();
while (lapic_cal_loops <= LAPIC_CAL_LOOPS) {
/* Wait for a tick to elapse */
while (1) {
if (tsc_khz) {
u64 tsc_now = rdtsc();
if ((tsc_now - tsc_start) >= tsc_perj) {
tsc_start += tsc_perj;
break;
}
} else {
unsigned long jif_now = READ_ONCE(jiffies);
if (time_after(jif_now, jif_start)) {
jif_start = jif_now;
break;
}
}
cpu_relax();
}
/* Invoke the calibration routine */
local_irq_disable();
lapic_cal_handler(NULL);
local_irq_enable();
}
local_irq_disable();
/* 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);
lapic_timer_period = (delta * APIC_DIVISOR) / LAPIC_CAL_LOOPS;
lapic_init_clockevent();
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_period);
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_period / (1000000 / HZ),
lapic_timer_period % (1000000 / HZ));
/*
* Do a sanity check on the APIC calibration result
*/
if (lapic_timer_period < (1000000 / HZ)) {
local_irq_enable();
pr_warn("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 a global clockevent device is
* available.
*/
if (!pm_referenced && global_clock_event) {
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_warn("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_warn("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 ... ]
*/
DEFINE_IDTENTRY_SYSVEC(sysvec_apic_timer_interrupt)
{
struct pt_regs *old_regs = set_irq_regs(regs);
ack_APIC_irq();
trace_local_timer_entry(LOCAL_TIMER_VECTOR);
local_apic_timer_interrupt();
trace_local_timer_exit(LOCAL_TIMER_VECTOR);
set_irq_regs(old_regs);
}
/*
* 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);
}
}
/**
* apic_soft_disable - Clears and software disables the local APIC on hotplug
*
* Contrary to disable_local_APIC() this does not touch the enable bit in
* MSR_IA32_APICBASE. Clearing that bit on systems based on the 3 wire APIC
* bus would require a hardware reset as the APIC would lose track of bus
* arbitration. On systems with FSB delivery APICBASE could be disabled,
* but it has to be guaranteed that no interrupt is sent to the APIC while
* in that state and it's not clear from the SDM whether it still responds
* to INIT/SIPI messages. Stay on the safe side and use software disable.
*/
void apic_soft_disable(void)
{
u32 value;
clear_local_APIC();
/* Soft disable APIC (implies clearing of registers for 82489DX!). */
value = apic_read(APIC_SPIV);
value &= ~APIC_SPIV_APIC_ENABLED;
apic_write(APIC_SPIV, value);
}
/**
* disable_local_APIC - clear and disable the local APIC
*/
void disable_local_APIC(void)
{
/* APIC hasn't been mapped yet */
if (!x2apic_mode && !apic_phys)
return;
apic_soft_disable();
#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 __ro_after_init;
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;
}
/* Select the interrupt delivery mode for the BSP */
void __init apic_intr_mode_select(void)
{
apic_intr_mode = __apic_intr_mode_select();
}
/*
* An initial setup of the virtual wire mode.
*/
void __init init_bsp_APIC(void)
{
unsigned int value;
/*
* Don't do the setup now if we have a SMP BIOS as the
* through-I/O-APIC virtual wire mode might be active.
*/
if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC))
return;
/*
* Do not trust the local APIC being empty at bootup.
*/
clear_local_APIC();
/*
* Enable APIC.
*/
value = apic_read(APIC_SPIV);
value &= ~APIC_VECTOR_MASK;
value |= APIC_SPIV_APIC_ENABLED;
#ifdef CONFIG_X86_32
/* This bit is reserved on P4/Xeon and should be cleared */
if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
(boot_cpu_data.x86 == 15))
value &= ~APIC_SPIV_FOCUS_DISABLED;
else
#endif
value |= APIC_SPIV_FOCUS_DISABLED;
value |= SPURIOUS_APIC_VECTOR;
apic_write(APIC_SPIV, value);
/*
* Set up the virtual wire mode.
*/
apic_write(APIC_LVT0, APIC_DM_EXTINT);
value = APIC_DM_NMI;
if (!lapic_is_integrated()) /* 82489DX */
value |= APIC_LVT_LEVEL_TRIGGER;
if (apic_extnmi == APIC_EXTNMI_NONE)
value |= APIC_LVT_MASKED;
apic_write(APIC_LVT1, value);
}
static void __init apic_bsp_setup(bool upmode);
/* Init the interrupt delivery mode for the BSP */
void __init apic_intr_mode_init(void)
{
bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT);
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");
break;
case APIC_VIRTUAL_WIRE_NO_CONFIG:
pr_info("APIC: Switch to virtual wire mode setup with no configuration\n");
upmode = true;
break;
case APIC_SYMMETRIC_IO:
pr_info("APIC: Switch to symmetric I/O mode setup\n");
break;
case APIC_SYMMETRIC_IO_NO_ROUTING:
pr_info("APIC: Switch to symmetric I/O mode setup in no SMP routine\n");
break;
}
default_setup_apic_routing();
if (x86_platform.apic_post_init)
x86_platform.apic_post_init();
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);
}
#define APIC_IR_REGS APIC_ISR_NR
#define APIC_IR_BITS (APIC_IR_REGS * 32)
#define APIC_IR_MAPSIZE (APIC_IR_BITS / BITS_PER_LONG)
union apic_ir {
unsigned long map[APIC_IR_MAPSIZE];
u32 regs[APIC_IR_REGS];
};
static bool apic_check_and_ack(union apic_ir *irr, union apic_ir *isr)
{
int i, bit;
/* Read the IRRs */
for (i = 0; i < APIC_IR_REGS; i++)
irr->regs[i] = apic_read(APIC_IRR + i * 0x10);
/* Read the ISRs */
for (i = 0; i < APIC_IR_REGS; i++)
isr->regs[i] = apic_read(APIC_ISR + i * 0x10);
/*
* If the ISR map is not empty. ACK the APIC and run another round
* to verify whether a pending IRR has been unblocked and turned
* into a ISR.
*/
if (!bitmap_empty(isr->map, APIC_IR_BITS)) {
/*
* There can be multiple ISR bits set when a high priority
* interrupt preempted a lower priority one. Issue an ACK
* per set bit.
*/
for_each_set_bit(bit, isr->map, APIC_IR_BITS)
ack_APIC_irq();
return true;
}
return !bitmap_empty(irr->map, APIC_IR_BITS);
}
/*
* 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 the 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 serviced the interrupt. Hence
* a vector might get locked. It was noticed for timer irq (vector
* 0x31). Issue an extra EOI to clear ISR.
*
* If there are pending IRR bits they turn into ISR bits after a higher
* priority ISR bit has been acked.
*/
static void apic_pending_intr_clear(void)
{
union apic_ir irr, isr;
unsigned int i;
/* 512 loops are way oversized and give the APIC a chance to obey. */
for (i = 0; i < 512; i++) {
if (!apic_check_and_ack(&irr, &isr))
return;
}
/* Dump the IRR/ISR content if that failed */
pr_warn("APIC: Stale IRR: %256pb ISR: %256pb\n", irr.map, isr.map);
}
/**
* 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;
if (disable_apic) {
disable_ioapic_support();
return;
}
/*
* If this comes from kexec/kcrash the APIC might be enabled in
* SPIV. Soft disable it before doing further initialization.
*/
value = apic_read(APIC_SPIV);
value &= ~APIC_SPIV_APIC_ENABLED;
apic_write(APIC_SPIV, value);
#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
/*
* 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
if (apic->dest_mode_logical) {
int logical_apicid, ldr_apicid;
/*
* 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));
if (logical_apicid != BAD_APICID)
WARN_ON(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 except vectors 0-31'. An APIC
* vector in the 16-31 range could be delivered if TPR == 0, but we
* would think it's an exception and terrible things will happen. We
* never change this later on.
*/
value = apic_read(APIC_TASKPRI);
value &= ~APIC_TPRI_MASK;
value |= 0x10;
apic_write(APIC_TASKPRI, value);
/* Clear eventually stale ISR/IRR bits */
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 distribution 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);
perf_events_lapic_init();
/*
* 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;
EXPORT_SYMBOL_GPL(x2apic_mode);
enum {
X2APIC_OFF,
X2APIC_DISABLED,
/* All states below here have X2APIC enabled */
X2APIC_ON,
X2APIC_ON_LOCKED
};
static int x2apic_state;
static bool x2apic_hw_locked(void)
{
u64 ia32_cap;
u64 msr;
ia32_cap = x86_read_arch_cap_msr();
if (ia32_cap & ARCH_CAP_XAPIC_DISABLE) {
rdmsrl(MSR_IA32_XAPIC_DISABLE_STATUS, msr);
return (msr & LEGACY_XAPIC_DISABLED);
}
return false;
}
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_warn("Apicid: %08x, cannot enforce nox2apic\n",
apicid);
return 0;
}
if (x2apic_hw_locked()) {
pr_warn("APIC locked in x2apic mode, can't disable\n");
return 0;
}
pr_warn("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)
{
/*
* Try to make the AP's APIC state match that of the BSP, but if the
* BSP is unlocked and the AP is locked then there is a state mismatch.
* Warn about the mismatch in case a GP fault occurs due to a locked AP
* trying to be turned off.
*/
if (x2apic_state != X2APIC_ON_LOCKED && x2apic_hw_locked())
pr_warn("x2apic lock mismatch between BSP and AP.\n");
/*
* If x2apic is not in ON or LOCKED 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);
if (x2apic_hw_locked()) {
pr_warn("Cannot disable locked x2apic, id: %08x\n", x2apic_id);
return;
}
__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) {
u32 apic_limit = 255;
/*
* Using X2APIC without IR is not architecturally supported
* on bare metal but may be supported in guests.
*/
if (!x86_init.hyper.x2apic_available()) {
pr_info("x2apic: IRQ remapping doesn't support X2APIC mode\n");
x2apic_disable();
return;
}
/*
* If the hypervisor supports extended destination ID in
* MSI, that increases the maximum APIC ID that can be
* used for non-remapped IRQ domains.
*/
if (x86_init.hyper.msi_ext_dest_id()) {
virt_ext_dest_id = 1;
apic_limit = 32767;
}
/*
* Without IR, all CPUs can be addressed by IOAPIC/MSI only
* in physical mode, and CPUs with an APIC ID that cannot
* be addressed must not be brought online.
*/
x2apic_set_max_apicid(apic_limit);
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;
if (x2apic_hw_locked())
x2apic_state = X2APIC_ON_LOCKED;
else
x2apic_state = X2APIC_ON;
} else if (!boot_cpu_has(X86_FEATURE_X2APIC)) {
x2apic_state = X2APIC_DISABLED;
}
}
#else /* CONFIG_X86_X2APIC */
void __init check_x2apic(void)
{
if (!apic_is_x2apic_enabled())
return;
/*
* Checkme: Can we simply turn off x2APIC here instead of disabling the APIC?
*/
pr_err("Kernel does not support x2APIC, please recompile with CONFIG_X86_X2APIC.\n");
pr_err("Disabling APIC, expect reduced performance and functionality.\n");
disable_apic = 1;
setup_clear_cpu_cap(X86_FEATURE_APIC);
}
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_warn("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_HYGON:
break;
case X86_VENDOR_INTEL:
if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
(boot_cpu_data.x86 == 5 && boot_cpu_has(X86_FEATURE_APIC)))
break;
goto no_apic;
default:
goto no_apic;
}
if (!boot_cpu_has(X86_FEATURE_APIC)) {
/*
* Over-ride BIOS and try to enable the local APIC only if
* "lapic" specified.
*/
if (!force_enable_local_apic) {
pr_info("Local APIC disabled by BIOS -- "
"you can enable it with \"lapic\"\n");
return -1;
}
if (apic_force_enable(APIC_DEFAULT_PHYS_BASE))
return -1;
} else {
if (apic_verify())
return -1;
}
apic_pm_activate();
return 0;
no_apic:
pr_info("No local APIC present or hardware disabled\n");
return -1;
}
#endif
/**
* init_apic_mappings - initialize APIC mappings
*/
void __init init_apic_mappings(void)
{
unsigned int new_apicid;
if (apic_validate_deadline_timer())
pr_info("TSC deadline timer available\n");
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);
6.5.5
2023-10-24 12:59:35 +02:00
apic_mmio_base = APIC_BASE;
Initial commit
2023-08-30 17:31:07 +02:00
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
*/
/*
* Common handling code for spurious_interrupt and spurious_vector entry
* points below. No point in allowing the compiler to inline it twice.
*/
static noinline void handle_spurious_interrupt(u8 vector)
{
u32 v;
trace_spurious_apic_entry(vector);
inc_irq_stat(irq_spurious_count);
/*
* If this is a spurious interrupt then do not acknowledge
*/
if (vector == SPURIOUS_APIC_VECTOR) {
/* See SDM vol 3 */
pr_info("Spurious APIC interrupt (vector 0xFF) on CPU#%d, should never happen.\n",
smp_processor_id());
goto out;
}
/*
* If it is a vectored one, verify it's set in the ISR. If set,
* acknowledge it.
*/
v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
if (v & (1 << (vector & 0x1f))) {
pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Acked\n",
vector, smp_processor_id());
ack_APIC_irq();
} else {
pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Not pending!\n",
vector, smp_processor_id());
}
out:
trace_spurious_apic_exit(vector);
}
/**
* spurious_interrupt - Catch all for interrupts raised on unused vectors
* @regs: Pointer to pt_regs on stack
* @vector: The vector number
*
* This is invoked from ASM entry code to catch all interrupts which
* trigger on an entry which is routed to the common_spurious idtentry
* point.
*/
DEFINE_IDTENTRY_IRQ(spurious_interrupt)
{
handle_spurious_interrupt(vector);
}
DEFINE_IDTENTRY_SYSVEC(sysvec_spurious_apic_interrupt)
{
handle_spurious_interrupt(SPURIOUS_APIC_VECTOR);
}
/*
* This interrupt should never happen with our APIC/SMP architecture
*/
DEFINE_IDTENTRY_SYSVEC(sysvec_error_interrupt)
{
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;
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);
}
/**
* 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.
*/
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int cpuid_to_apicid[] = {
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[0 ... NR_CPUS - 1] = -1,
};
bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
{
return phys_id == cpuid_to_apicid[cpu];
}
#ifdef CONFIG_SMP
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static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
{
/* Isolate the SMT bit(s) in the APICID and check for 0 */
u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
if (smp_num_siblings == 1 || !(apicid & mask))
cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
}
/*
* Due to the utter mess of CPUID evaluation smp_num_siblings is not valid
* during early boot. Initialize the primary thread mask before SMP
* bringup.
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*/
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static int __init smp_init_primary_thread_mask(void)
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{
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unsigned int cpu;
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for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
return 0;
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}
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early_initcall(smp_init_primary_thread_mask);
#else
static inline void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid) { }
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#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_warn("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_warn("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_warn("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_warn("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_warn("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++;
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if (system_state != SYSTEM_BOOTING)
cpu_mark_primary_thread(cpu, apicid);
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return cpu;
}
int hard_smp_processor_id(void)
{
return read_apic_id();
}
void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg,
bool dmar)
{
memset(msg, 0, sizeof(*msg));
msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
msg->arch_addr_lo.dest_mode_logical = apic->dest_mode_logical;
msg->arch_addr_lo.destid_0_7 = cfg->dest_apicid & 0xFF;
msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_FIXED;
msg->arch_data.vector = cfg->vector;
msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
/*
* Only the IOMMU itself can use the trick of putting destination
* APIC ID into the high bits of the address. Anything else would
* just be writing to memory if it tried that, and needs IR to
* address APICs which can't be addressed in the normal 32-bit
* address range at 0xFFExxxxx. That is typically just 8 bits, but
* some hypervisors allow the extended destination ID field in bits
* 5-11 to be used, giving support for 15 bits of APIC IDs in total.
*/
if (dmar)
msg->arch_addr_hi.destid_8_31 = cfg->dest_apicid >> 8;
else if (virt_ext_dest_id && cfg->dest_apicid < 0x8000)
msg->arch_addr_lo.virt_destid_8_14 = cfg->dest_apicid >> 8;
else
WARN_ON_ONCE(cfg->dest_apicid > 0xFF);
}
u32 x86_msi_msg_get_destid(struct msi_msg *msg, bool extid)
{
u32 dest = msg->arch_addr_lo.destid_0_7;
if (extid)
dest |= msg->arch_addr_hi.destid_8_31 << 8;
return dest;
}
EXPORT_SYMBOL_GPL(x86_msi_msg_get_destid);
#ifdef CONFIG_X86_64
void __init acpi_wake_cpu_handler_update(wakeup_cpu_handler handler)
{
struct apic **drv;
for (drv = __apicdrivers; drv < __apicdrivers_end; drv++)
(*drv)->wakeup_secondary_cpu_64 = handler;
}
#endif
/*
* 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)
*/
static 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();
lapic_update_legacy_vectors();
}
#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);
/*
* Mask IOAPIC before disabling the local APIC to prevent stale IRR
* entries on some implementations.
*/
mask_ioapic_entries();
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_warn("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);