// 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.
*/
/* Processor that is doing the boot up */
u32 boot_cpu_physical_apicid __ro_after_init = BAD_APICID;
EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);
u8 boot_cpu_apic_version __ro_after_init;
/* * This variable controls which CPUs receive external NMIs. By default, * external NMIs are delivered only to the BSP.
*/ staticint apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;
/* * Hypervisor supports 15 bits of APIC ID in MSI Extended Destination ID
*/ staticbool virt_ext_dest_id __ro_after_init;
/* For parallel bootup. */ unsignedlong apic_mmio_base __ro_after_init;
#ifdef CONFIG_X86_32 /* Local APIC was disabled by the BIOS and enabled by the kernel */ staticint 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.
*/ staticinlinevoid imcr_pic_to_apic(void)
{ /* NMI and 8259 INTR go through APIC */
pc_conf_set(PC_CONF_MPS_IMCR, 0x01);
}
staticinlinevoid 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
*/ staticint force_enable_local_apic __initdata;
staticunsignedlong mp_lapic_addr __ro_after_init; bool apic_is_disabled __ro_after_init; /* Disable local APIC timer from the kernel commandline or via dmi quirk */ staticint 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;
/* * Get the LAPIC version
*/ staticinlineint lapic_get_version(void)
{ return GET_APIC_VERSION(apic_read(APIC_LVR));
}
/* * Check, if the APIC is integrated or a separate chip
*/ staticinlineint lapic_is_integrated(void)
{ return APIC_INTEGRATED(lapic_get_version());
}
/* * Check, whether this is a modern or a first generation APIC
*/ staticint 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
*/ staticvoid __init apic_disable(void)
{
apic_install_driver(&apic_noop);
}
/** * 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;
}
/* 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.
*/ staticvoid __setup_APIC_LVTT(unsignedint clocks, int oneshot, int irqen)
{ unsignedint lvtt_value, tmp_value;
/* * 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.
*/ asmvolatile("mfence" : : : "memory"); return;
}
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.
*/
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);
returnnew;
}
/* * 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.
*/
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
*/ staticint lapic_next_event(unsignedlong delta, struct clock_event_device *evt)
{
apic_write(APIC_TMICT, delta); return 0;
}
/* 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);
/* * Setting APIC_LVT_MASKED (above) should be enough to tell * the hardware that this timer will never fire. But AMD * erratum 411 and some Intel CPU behavior circa 2024 say * otherwise. Time for belt and suspenders programming: mask * the timer _and_ zero the counter registers:
*/ if (v & APIC_LVT_TIMER_TSCDEADLINE)
wrmsrq(MSR_IA32_TSC_DEADLINE, 0); else
apic_write(APIC_TMICT, 0);
return 0;
}
staticinlineint
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;
if (!boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) returnfalse; if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) returntrue;
m = x86_match_cpu(deadline_match); if (!m) returntrue;
rev = (u32)m->driver_data;
if (boot_cpu_data.microcode >= rev) returntrue;
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); returnfalse;
}
/* * Setup the local APIC timer for this CPU. Copy the initialized values * of the boot CPU and register the clock event in the framework.
*/ staticvoid 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;
}
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).
*/
/* 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_pr_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", (unsignedlong)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_pr_verbose("TSC delta adjusted to PM-Timer: %lu (%ld)\n",
(unsignedlong)res, *deltatsc);
*deltatsc = (long)res;
}
return 0;
}
staticint __init lapic_init_clockevent(void)
{ if (!lapic_timer_period) return -1;
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) returntrue;
/* Is there an APIC at all or is it disabled? */ if (!boot_cpu_has(X86_FEATURE_APIC) || apic_is_disabled) returntrue;
/* * If interrupt delivery mode is legacy PIC or virtual wire without * configuration, the local APIC timer won't be set up. Make sure * that the PIT is initialized.
*/ if (apic_intr_mode == APIC_PIC ||
apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG) returntrue;
/* Virt guests may lack ARAT, but still have DEADLINE */ if (!boot_cpu_has(X86_FEATURE_ARAT)) returntrue;
/* Deadline timer is based on TSC so no further PIT action required */ if (boot_cpu_has(X86_FEATURE_TSC_DEADLINE_TIMER)) returnfalse;
/* APIC timer disabled? */ if (disable_apic_timer) returntrue; /* * The APIC timer frequency is known already, no PIT calibration * required. If unknown, let the PIT be initialized.
*/ return lapic_timer_period == 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_pr_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_pr_verbose("Using local APIC timer interrupts. 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 (boot_cpu_has(X86_FEATURE_TSC)) {
apic_pr_verbose("..... CPU clock speed is %ld.%04ld MHz.\n",
(deltatsc / LAPIC_CAL_LOOPS) / (1000000 / HZ),
(deltatsc / LAPIC_CAL_LOOPS) % (1000000 / HZ));
}
apic_pr_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_pr_verbose("... verify APIC timer\n");
/* Check, if the jiffies result is consistent */ if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
apic_pr_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();
}
/* * The guts of the apic timer interrupt
*/ staticvoid 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);
/** * 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;
if (!apic_accessible()) 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)
{ if (!apic_accessible()) 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) { unsignedint l, h;
/* * If Linux enabled the LAPIC against the BIOS default disable it down before * re-entering the BIOS on shutdown. Otherwise the BIOS may get confused and * not power-off. Additionally clear all LVT entries before disable_local_APIC * for the case where Linux didn't enable the LAPIC.
*/ void lapic_shutdown(void)
{ unsignedlong 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;
/* 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)) {
apic_is_disabled = true;
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) {
apic_is_disabled = true; 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)) {
apic_is_disabled = true;
pr_err(FW_BUG "Local APIC not detected, force emulation\n"); 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;
} #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)
{ unsignedint 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);
}
staticvoid __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;
}
x86_64_probe_apic();
if (x86_platform.apic_post_init)
x86_platform.apic_post_init();
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_pr_verbose("ESR value before enabling vector: 0x%08x after: 0x%08x\n",
oldvalue, value);
}
}
union apic_ir { unsignedlong map[APIC_IR_MAPSIZE];
u32 regs[APIC_IR_REGS];
};
staticbool 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)
apic_eoi(); returntrue;
}
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 apic_eoi() 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.
*/ staticvoid apic_pending_intr_clear(void)
{ union apic_ir irr, isr; unsignedint 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.
*/ staticvoid setup_local_APIC(void)
{ int cpu = smp_processor_id(); unsignedint value;
if (apic_is_disabled) {
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 /* * 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). * * Except for APICs which operate in physical destination mode.
*/ if (apic->init_apic_ldr)
apic->init_apic_ldr();
/* * 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 || ioapic_is_disabled)) {
value = APIC_DM_EXTINT;
apic_pr_verbose("Enabled ExtINT on CPU#%d\n", cpu);
} else {
value = APIC_DM_EXTINT | APIC_LVT_MASKED;
apic_pr_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
}
#ifdef CONFIG_X86_32
{ unsignedint 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();
}
static __init void apic_read_boot_cpu_id(bool x2apic)
{ /* * This can be invoked from check_x2apic() before the APIC has been * selected. But that code knows for sure that the BIOS enabled * X2APIC.
*/ if (x2apic) {
boot_cpu_physical_apicid = native_apic_msr_read(APIC_ID);
boot_cpu_apic_version = GET_APIC_VERSION(native_apic_msr_read(APIC_LVR));
} else {
boot_cpu_physical_apicid = read_apic_id();
boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));
}
topology_register_boot_apic(boot_cpu_physical_apicid);
}
#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
}; staticint x2apic_state;
/* 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();
}
/* * Don't reread the APIC ID as it was already done from * check_x2apic() and the APIC driver still is a x2APIC variant, * which fails to do the read after x2APIC was disabled.
*/
apic_set_fixmap(false);
}
static __init void x2apic_enable(void)
{ if (x2apic_state != X2APIC_OFF) 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;
apic_read_boot_cpu_id(true);
} elseif (!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");
/* 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.)
*/ staticbool __init detect_init_APIC(void)
{ if (!boot_cpu_has(X86_FEATURE_APIC)) {
pr_info("No local APIC present\n"); returnfalse;
}
/* * 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"); returnfalse;
}
set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
/* 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)
addr = l & MSR_IA32_APICBASE_BASE;
}
register_lapic_address(addr);
pr_info("Found and enabled local APIC!\n"); returntrue;
}
/* * 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(addr);
}
/* * Detect and initialize APIC
*/ staticbool __init detect_init_APIC(void)
{ /* Disabled by kernel option? */ if (apic_is_disabled) returnfalse;
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 == 5 && boot_cpu_has(X86_FEATURE_APIC)) ||
boot_cpu_data.x86_vfm >= INTEL_PENTIUM_PRO) 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"); returnfalse;
} if (!apic_force_enable(APIC_DEFAULT_PHYS_BASE)) returnfalse;
} else { if (!apic_verify(APIC_DEFAULT_PHYS_BASE)) returnfalse;
}
apic_pm_activate();
returntrue;
no_apic:
pr_info("No local APIC present or hardware disabled\n"); returnfalse;
} #endif
void __init register_lapic_address(unsignedlong address)
{ /* This should only happen once */
WARN_ON_ONCE(mp_lapic_addr);
mp_lapic_addr = address;
if (!x2apic_mode)
apic_set_fixmap(true);
}
/* * 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());
apic_eoi();
} 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);
}
/* * This interrupt should never happen with our APIC/SMP architecture
*/
DEFINE_IDTENTRY_SYSVEC(sysvec_error_interrupt)
{ staticconstchar * 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);
apic_eoi();
atomic_inc(&irq_err_count);
apic_pr_debug("APIC error on CPU%d: %02x", smp_processor_id(), v);
v &= 0xff; while (v) { if (v & 0x1)
apic_pr_debug_cont(" : %s", error_interrupt_reason[i]);
i++;
v >>= 1;
}
apic_pr_debug_cont("\n");
trace_error_apic_exit(ERROR_APIC_VECTOR);
}
/** * connect_bsp_APIC - attach the APIC to the interrupt system
*/ staticvoid __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_pr_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)
{ unsignedint 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_pr_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);
}
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; elseif (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);
}
/** * apic_bsp_setup - Setup function for local apic and io-apic * @upmode: Force UP mode (for APIC_init_uniprocessor)
*/ staticvoid __init apic_bsp_setup(bool upmode)
{
connect_bsp_APIC(); if (upmode)
apic_bsp_up_setup();
setup_local_APIC();
/* Setup local timer */
x86_init.timers.setup_percpu_clockev();
} #endif
/* * Power management
*/ #ifdef CONFIG_PM
staticstruct { /* * '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 */
u32 apic_id; unsignedint apic_taskpri; unsignedint apic_ldr; unsignedint apic_dfr; unsignedint apic_spiv; unsignedint apic_lvtt; unsignedint apic_lvtpc; unsignedint apic_lvt0; unsignedint apic_lvt1; unsignedint apic_lvterr; unsignedint apic_tmict; unsignedint apic_tdcr; unsignedint apic_thmr; unsignedint apic_cmci;
} apic_pm_state;
staticint lapic_suspend(void)
{ unsignedlong flags; int maxlvt;
/* * 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;
}
staticvoid lapic_resume(void)
{ unsignedint l, h; unsignedlong 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);
}
}
/* * 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();
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