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Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
-rw-r--r--arch/x86/kernel/apic/apic.c113
1 files changed, 62 insertions, 51 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index dcb52850a28f..24e94ce454e2 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -336,6 +336,13 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
apic_write(APIC_LVTT, lvtt_value);
if (lvtt_value & APIC_LVT_TIMER_TSCDEADLINE) {
+ /*
+ * See Intel SDM: TSC-Deadline Mode chapter. In xAPIC mode,
+ * writing to the APIC LVTT and TSC_DEADLINE MSR isn't serialized.
+ * According to Intel, MFENCE can do the serialization here.
+ */
+ asm volatile("mfence" : : : "memory");
+
printk_once(KERN_DEBUG "TSC deadline timer enabled\n");
return;
}
@@ -457,45 +464,45 @@ static int lapic_next_deadline(unsigned long delta,
{
u64 tsc;
- rdtscll(tsc);
+ tsc = rdtsc();
wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
return 0;
}
-/*
- * Setup the lapic timer in periodic or oneshot mode
- */
-static void lapic_timer_setup(enum clock_event_mode mode,
- struct clock_event_device *evt)
+static int lapic_timer_shutdown(struct clock_event_device *evt)
{
- unsigned long flags;
unsigned int v;
/* Lapic used as dummy for broadcast ? */
if (evt->features & CLOCK_EVT_FEAT_DUMMY)
- return;
+ return 0;
- local_irq_save(flags);
+ v = apic_read(APIC_LVTT);
+ v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+ apic_write(APIC_LVTT, v);
+ apic_write(APIC_TMICT, 0);
+ return 0;
+}
- switch (mode) {
- case CLOCK_EVT_MODE_PERIODIC:
- case CLOCK_EVT_MODE_ONESHOT:
- __setup_APIC_LVTT(lapic_timer_frequency,
- mode != CLOCK_EVT_MODE_PERIODIC, 1);
- break;
- case CLOCK_EVT_MODE_UNUSED:
- case CLOCK_EVT_MODE_SHUTDOWN:
- v = apic_read(APIC_LVTT);
- v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
- apic_write(APIC_LVTT, v);
- apic_write(APIC_TMICT, 0);
- break;
- case CLOCK_EVT_MODE_RESUME:
- /* Nothing to do here */
- break;
- }
+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;
- local_irq_restore(flags);
+ __setup_APIC_LVTT(lapic_timer_frequency, oneshot, 1);
+ return 0;
+}
+
+static int lapic_timer_set_periodic(struct clock_event_device *evt)
+{
+ return lapic_timer_set_periodic_oneshot(evt, false);
+}
+
+static int lapic_timer_set_oneshot(struct clock_event_device *evt)
+{
+ return lapic_timer_set_periodic_oneshot(evt, true);
}
/*
@@ -513,15 +520,18 @@ static void lapic_timer_broadcast(const struct cpumask *mask)
* The local apic timer can be used for any function which is CPU local.
*/
static struct clock_event_device lapic_clockevent = {
- .name = "lapic",
- .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
- | CLOCK_EVT_FEAT_C3STOP | CLOCK_EVT_FEAT_DUMMY,
- .shift = 32,
- .set_mode = lapic_timer_setup,
- .set_next_event = lapic_next_event,
- .broadcast = lapic_timer_broadcast,
- .rating = 100,
- .irq = -1,
+ .name = "lapic",
+ .features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP
+ | CLOCK_EVT_FEAT_DUMMY,
+ .shift = 32,
+ .set_state_shutdown = lapic_timer_shutdown,
+ .set_state_periodic = lapic_timer_set_periodic,
+ .set_state_oneshot = lapic_timer_set_oneshot,
+ .set_next_event = lapic_next_event,
+ .broadcast = lapic_timer_broadcast,
+ .rating = 100,
+ .irq = -1,
};
static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
@@ -592,7 +602,7 @@ static void __init lapic_cal_handler(struct clock_event_device *dev)
unsigned long pm = acpi_pm_read_early();
if (cpu_has_tsc)
- rdtscll(tsc);
+ tsc = rdtsc();
switch (lapic_cal_loops++) {
case 0:
@@ -778,7 +788,7 @@ static int __init calibrate_APIC_clock(void)
* Setup the apic timer manually
*/
levt->event_handler = lapic_cal_handler;
- lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
+ lapic_timer_set_periodic(levt);
lapic_cal_loops = -1;
/* Let the interrupts run */
@@ -788,7 +798,8 @@ static int __init calibrate_APIC_clock(void)
cpu_relax();
/* Stop the lapic timer */
- lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
+ local_irq_disable();
+ lapic_timer_shutdown(levt);
/* Jiffies delta */
deltaj = lapic_cal_j2 - lapic_cal_j1;
@@ -799,8 +810,8 @@ static int __init calibrate_APIC_clock(void)
apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
else
levt->features |= CLOCK_EVT_FEAT_DUMMY;
- } else
- local_irq_enable();
+ }
+ local_irq_enable();
if (levt->features & CLOCK_EVT_FEAT_DUMMY) {
pr_warning("APIC timer disabled due to verification failure\n");
@@ -878,7 +889,7 @@ static void local_apic_timer_interrupt(void)
if (!evt->event_handler) {
pr_warning("Spurious LAPIC timer interrupt on cpu %d\n", cpu);
/* Switch it off */
- lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
+ lapic_timer_shutdown(evt);
return;
}
@@ -1209,7 +1220,7 @@ void setup_local_APIC(void)
long long max_loops = cpu_khz ? cpu_khz : 1000000;
if (cpu_has_tsc)
- rdtscll(tsc);
+ tsc = rdtsc();
if (disable_apic) {
disable_ioapic_support();
@@ -1293,7 +1304,7 @@ void setup_local_APIC(void)
}
if (queued) {
if (cpu_has_tsc && cpu_khz) {
- rdtscll(ntsc);
+ ntsc = rdtsc();
max_loops = (cpu_khz << 10) - (ntsc - tsc);
} else
max_loops--;
@@ -1424,7 +1435,7 @@ static inline void __x2apic_disable(void)
{
u64 msr;
- if (cpu_has_apic)
+ if (!cpu_has_apic)
return;
rdmsrl(MSR_IA32_APICBASE, msr);
@@ -1483,10 +1494,13 @@ void x2apic_setup(void)
static __init void x2apic_disable(void)
{
- u32 x2apic_id;
+ u32 x2apic_id, state = x2apic_state;
- if (x2apic_state != X2APIC_ON)
- goto out;
+ x2apic_mode = 0;
+ x2apic_state = X2APIC_DISABLED;
+
+ if (state != X2APIC_ON)
+ return;
x2apic_id = read_apic_id();
if (x2apic_id >= 255)
@@ -1494,9 +1508,6 @@ static __init void x2apic_disable(void)
__x2apic_disable();
register_lapic_address(mp_lapic_addr);
-out:
- x2apic_state = X2APIC_DISABLED;
- x2apic_mode = 0;
}
static __init void x2apic_enable(void)
generated by cgit v1.2.3 (git 2.39.0) at 2025-03-13 16:19:09 +0300