x86_64: Add (not yet used) clock event functions

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 40938ef..2c2807a 100644 (file)
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -25,6 +25,7 @@
 #include <linux/sysdev.h>
 #include <linux/module.h>
 #include <linux/ioport.h>
+#include <linux/clockchips.h>
 
 #include <asm/atomic.h>
 #include <asm/smp.h>
@@ -57,6 +58,77 @@ static struct resource lapic_resource = {
 
 static unsigned int calibration_result;
 
+static int lapic_next_event(unsigned long delta,
+                           struct clock_event_device *evt);
+static void lapic_timer_setup(enum clock_event_mode mode,
+                             struct clock_event_device *evt);
+
+static void lapic_timer_broadcast(cpumask_t mask);
+
+static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen);
+
+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,
+};
+static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
+
+static int lapic_next_event(unsigned long delta,
+                           struct clock_event_device *evt)
+{
+       apic_write(APIC_TMICT, delta);
+       return 0;
+}
+
+static void lapic_timer_setup(enum clock_event_mode mode,
+                             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;
+
+       local_irq_save(flags);
+
+       switch (mode) {
+       case CLOCK_EVT_MODE_PERIODIC:
+       case CLOCK_EVT_MODE_ONESHOT:
+               __setup_APIC_LVTT(calibration_result,
+                                 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);
+               break;
+       case CLOCK_EVT_MODE_RESUME:
+               /* Nothing to do here */
+               break;
+       }
+
+       local_irq_restore(flags);
+}
+
+/*
+ * Local APIC timer broadcast function
+ */
+static void lapic_timer_broadcast(cpumask_t mask)
+{
+#ifdef CONFIG_SMP
+       send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
+#endif
+}
+
 /*
  * cpu_mask that denotes the CPUs that needs timer interrupt coming in as
  * IPIs in place of local APIC timers
@@ -866,6 +938,13 @@ static void __init calibrate_APIC_clock(void)
        printk(KERN_INFO "Detected %d.%03d MHz APIC timer.\n",
                result / 1000 / 1000, result / 1000 % 1000);
 
+       /* Calculate the scaled math multiplication factor */
+       lapic_clockevent.mult = div_sc(result, NSEC_PER_SEC, 32);
+       lapic_clockevent.max_delta_ns =
+               clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
+       lapic_clockevent.min_delta_ns =
+               clockevent_delta2ns(0xF, &lapic_clockevent);
+
        calibration_result = result / HZ;
 }
 

diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 520f33b..a9534c2 100644 (file)
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -40,6 +40,10 @@ config CLOCKSOURCE_WATCHDOG
        bool
        default y
 
+config GENERIC_CLOCKEVENTS_MIGR
+       bool
+       default y
+
 config ZONE_DMA32
        bool
        default y
@@ -134,6 +138,8 @@ source "init/Kconfig"
 
 menu "Processor type and features"
 
+source "kernel/time/Kconfig"
+
 choice
        prompt "Subarchitecture Type"
        default X86_PC