xen/15189-pmtimer.patch

94 lines
2.9 KiB
Diff

# HG changeset 15189 patch
# User kfraser@localhost.localdomain
# Node ID 2d7d33ac982a0720408d841b13c3b97a2190eae4
# Parent ae073ca6eb76f75a73063ba6e0f944b47b8f8954
Add support for ACPI PM Timer as platform clock source.
Signed-off-by: Keir Fraser <keir@xensource.com>
Index: 2007-05-14/xen/arch/x86/time.c
===================================================================
--- 2007-05-14.orig/xen/arch/x86/time.c 2007-04-23 10:01:42.000000000 +0200
+++ 2007-05-14/xen/arch/x86/time.c 2007-07-02 10:47:59.000000000 +0200
@@ -511,6 +511,60 @@ static int init_cyclone(void)
}
/************************************************************
+ * PLATFORM TIMER 4: ACPI PM TIMER
+ */
+
+u32 pmtmr_ioport;
+
+/* Protected by platform_timer_lock. */
+static u64 pmtimer_counter64;
+static u32 pmtimer_stamp;
+static struct timer pmtimer_overflow_timer;
+
+/* ACPI PM timer ticks at 3.579545 MHz. */
+#define ACPI_PM_FREQUENCY 3579545
+
+/* Deltas are 24-bit unsigned values, as counter may be only 24 bits wide. */
+#define pmtimer_delta(c) ((u32)(((c) - pmtimer_stamp) & ((1U<<24)-1)))
+
+static void pmtimer_overflow(void *unused)
+{
+ u32 counter;
+
+ spin_lock_irq(&platform_timer_lock);
+ counter = inl(pmtmr_ioport);
+ pmtimer_counter64 += pmtimer_delta(counter);
+ pmtimer_stamp = counter;
+ spin_unlock_irq(&platform_timer_lock);
+
+ /* Trigger overflow avoidance roughly when counter increments 2^23. */
+ set_timer(&pmtimer_overflow_timer, NOW() + MILLISECS(2000));
+}
+
+static u64 read_pmtimer_count(void)
+{
+ return pmtimer_counter64 + pmtimer_delta(inl(pmtmr_ioport));
+}
+
+static int init_pmtimer(void)
+{
+ if ( pmtmr_ioport == 0 )
+ return 0;
+
+ read_platform_count = read_pmtimer_count;
+
+ init_timer(&pmtimer_overflow_timer, pmtimer_overflow, NULL, 0);
+ pmtimer_overflow(NULL);
+ platform_timer_stamp = pmtimer_counter64;
+ set_time_scale(&platform_timer_scale, ACPI_PM_FREQUENCY);
+
+ printk("Platform timer is %s ACPI PM Timer\n",
+ freq_string(ACPI_PM_FREQUENCY));
+
+ return 1;
+}
+
+/************************************************************
* GENERIC PLATFORM TIMER INFRASTRUCTURE
*/
@@ -549,7 +603,7 @@ static void platform_time_calibration(vo
static void init_platform_timer(void)
{
- if ( !init_cyclone() && !init_hpet() )
+ if ( !init_cyclone() && !init_hpet() && !init_pmtimer() )
init_pit();
}
Index: 2007-05-14/xen/include/asm-x86/config.h
===================================================================
--- 2007-05-14.orig/xen/include/asm-x86/config.h 2007-04-23 10:01:46.000000000 +0200
+++ 2007-05-14/xen/include/asm-x86/config.h 2007-07-02 10:47:59.000000000 +0200
@@ -22,6 +22,7 @@
#define CONFIG_X86_LOCAL_APIC 1
#define CONFIG_X86_GOOD_APIC 1
#define CONFIG_X86_IO_APIC 1
+#define CONFIG_X86_PM_TIMER 1
#define CONFIG_HPET_TIMER 1
#define CONFIG_X86_MCE_P4THERMAL 1
#define CONFIG_ACPI_NUMA 1