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Diffstat (limited to 'arch/i386/kernel/apic.c')
-rw-r--r--arch/i386/kernel/apic.c132
1 files changed, 74 insertions, 58 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 9655c233e6f1..93aa911646ad 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -28,6 +28,7 @@
#include <linux/clockchips.h>
#include <linux/acpi_pmtmr.h>
#include <linux/module.h>
+#include <linux/dmi.h>
#include <asm/atomic.h>
#include <asm/smp.h>
@@ -38,7 +39,6 @@
#include <asm/hpet.h>
#include <asm/i8253.h>
#include <asm/nmi.h>
-#include <asm/idle.h>
#include <mach_apic.h>
#include <mach_apicdef.h>
@@ -62,6 +62,11 @@ static int enable_local_apic __initdata = 0;
/* Local APIC timer verification ok */
static int local_apic_timer_verify_ok;
+/* Disable local APIC timer from the kernel commandline or via dmi quirk */
+static int local_apic_timer_disabled;
+/* Local APIC timer works in C2 */
+int local_apic_timer_c2_ok;
+EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);
/*
* Debug level, exported for io_apic.c
@@ -339,6 +344,23 @@ void __init setup_boot_APIC_clock(void)
void (*real_handler)(struct clock_event_device *dev);
unsigned long deltaj;
long delta, deltapm;
+ int pm_referenced = 0;
+
+ if (boot_cpu_has(X86_FEATURE_LAPIC_TIMER_BROKEN))
+ local_apic_timer_disabled = 1;
+
+ /*
+ * The local apic timer can be disabled via the kernel
+ * commandline or from the test above. Register the lapic
+ * timer as a dummy clock event source on SMP systems, so the
+ * broadcast mechanism is used. On UP systems simply ignore it.
+ */
+ if (local_apic_timer_disabled) {
+ /* No broadcast on UP ! */
+ if (num_possible_cpus() > 1)
+ setup_APIC_timer();
+ return;
+ }
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
"calibrating APIC timer ...\n");
@@ -358,7 +380,8 @@ void __init setup_boot_APIC_clock(void)
/* Let the interrupts run */
local_irq_enable();
- while(lapic_cal_loops <= LAPIC_CAL_LOOPS);
+ while (lapic_cal_loops <= LAPIC_CAL_LOOPS)
+ cpu_relax();
local_irq_disable();
@@ -395,6 +418,7 @@ void __init setup_boot_APIC_clock(void)
"%lu (%ld)\n", (unsigned long) res, delta);
delta = (long) res;
}
+ pm_referenced = 1;
}
/* Calculate the scaled math multiplication factor */
@@ -424,69 +448,43 @@ void __init setup_boot_APIC_clock(void)
calibration_result / (1000000 / HZ),
calibration_result % (1000000 / HZ));
-
- apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
-
- /*
- * Setup the apic timer manually
- */
local_apic_timer_verify_ok = 1;
- levt->event_handler = lapic_cal_handler;
- lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
- lapic_cal_loops = -1;
- /* Let the interrupts run */
- local_irq_enable();
+ /* We trust the pm timer based calibration */
+ if (!pm_referenced) {
+ apic_printk(APIC_VERBOSE, "... verify APIC timer\n");
- while(lapic_cal_loops <= LAPIC_CAL_LOOPS);
+ /*
+ * Setup the apic timer manually
+ */
+ levt->event_handler = lapic_cal_handler;
+ lapic_timer_setup(CLOCK_EVT_MODE_PERIODIC, levt);
+ lapic_cal_loops = -1;
- local_irq_disable();
+ /* Let the interrupts run */
+ local_irq_enable();
- /* Stop the lapic timer */
- lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
+ while(lapic_cal_loops <= LAPIC_CAL_LOOPS)
+ cpu_relax();
- local_irq_enable();
+ local_irq_disable();
- /* Jiffies delta */
- deltaj = lapic_cal_j2 - lapic_cal_j1;
- apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
+ /* Stop the lapic timer */
+ lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, levt);
- /* Check, if the PM timer is available */
- deltapm = lapic_cal_pm2 - lapic_cal_pm1;
- apic_printk(APIC_VERBOSE, "... PM timer delta = %ld\n", deltapm);
+ local_irq_enable();
- local_apic_timer_verify_ok = 0;
+ /* Jiffies delta */
+ deltaj = lapic_cal_j2 - lapic_cal_j1;
+ apic_printk(APIC_VERBOSE, "... jiffies delta = %lu\n", deltaj);
- if (deltapm) {
- if (deltapm > (pm_100ms - pm_thresh) &&
- deltapm < (pm_100ms + pm_thresh)) {
- apic_printk(APIC_VERBOSE, "... PM timer result ok\n");
- /* Check, if the jiffies result is consistent */
- if (deltaj < LAPIC_CAL_LOOPS-2 ||
- deltaj > LAPIC_CAL_LOOPS+2) {
- /*
- * Not sure, what we can do about this one.
- * When high resultion timers are active
- * and the lapic timer does not stop in C3
- * we are fine. Otherwise more trouble might
- * be waiting. -- tglx
- */
- printk(KERN_WARNING "Global event device %s "
- "has wrong frequency "
- "(%lu ticks instead of %d)\n",
- global_clock_event->name, deltaj,
- LAPIC_CAL_LOOPS);
- }
- local_apic_timer_verify_ok = 1;
- }
- } else {
/* Check, if the jiffies result is consistent */
- if (deltaj >= LAPIC_CAL_LOOPS-2 &&
- deltaj <= LAPIC_CAL_LOOPS+2) {
+ if (deltaj >= LAPIC_CAL_LOOPS-2 && deltaj <= LAPIC_CAL_LOOPS+2)
apic_printk(APIC_VERBOSE, "... jiffies result ok\n");
- local_apic_timer_verify_ok = 1;
- }
- }
+ else
+ local_apic_timer_verify_ok = 0;
+ } else
+ local_irq_enable();
if (!local_apic_timer_verify_ok) {
printk(KERN_WARNING
@@ -494,8 +492,15 @@ void __init setup_boot_APIC_clock(void)
/* No broadcast on UP ! */
if (num_possible_cpus() == 1)
return;
- } else
- lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+ } else {
+ /*
+ * If nmi_watchdog is set to IO_APIC, we need the
+ * PIT/HPET going. Otherwise register lapic as a dummy
+ * device.
+ */
+ if (nmi_watchdog != NMI_IO_APIC)
+ lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+ }
/* Setup the lapic or request the broadcast */
setup_APIC_timer();
@@ -561,7 +566,6 @@ void fastcall smp_apic_timer_interrupt(struct pt_regs *regs)
* Besides, if we don't timer interrupts ignore the global
* interrupt lock, which is the WrongThing (tm) to do.
*/
- exit_idle();
irq_enter();
local_apic_timer_interrupt();
irq_exit();
@@ -1198,6 +1202,20 @@ static int __init parse_nolapic(char *arg)
}
early_param("nolapic", parse_nolapic);
+static int __init parse_disable_lapic_timer(char *arg)
+{
+ local_apic_timer_disabled = 1;
+ return 0;
+}
+early_param("nolapic_timer", parse_disable_lapic_timer);
+
+static int __init parse_lapic_timer_c2_ok(char *arg)
+{
+ local_apic_timer_c2_ok = 1;
+ return 0;
+}
+early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
+
static int __init apic_set_verbosity(char *str)
{
if (strcmp("debug", str) == 0)
@@ -1221,7 +1239,6 @@ void smp_spurious_interrupt(struct pt_regs *regs)
{
unsigned long v;
- exit_idle();
irq_enter();
/*
* Check if this really is a spurious interrupt and ACK it
@@ -1245,7 +1262,6 @@ void smp_error_interrupt(struct pt_regs *regs)
{
unsigned long v, v1;
- exit_idle();
irq_enter();
/* First tickle the hardware, only then report what went on. -- REW */
v = apic_read(APIC_ESR);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.