[PATCH] adjust i386 watchdog tick calculation
From: Jan Beulich
Date: Thu May 12 2005 - 03:18:43 EST
(Note: Patch also attached because the inline version is certain to get
line wrapped.)
Get the i386 watchdog tick calculation into a state where it can also
be used on CPUs with frequencies beyond 4GHz, and it consolidates the
calculation into a single place (for potential furture adjustments).
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
diff -Npru linux-2.6.12-rc4.base/arch/i386/kernel/nmi.c linux-2.6.12-rc4/arch/i386/kernel/nmi.c
--- linux-2.6.12-rc4.base/arch/i386/kernel/nmi.c 2005-05-11 17:27:52.239252272 +0200
+++ linux-2.6.12-rc4/arch/i386/kernel/nmi.c 2005-05-11 17:50:36.249891136 +0200
@@ -28,8 +28,7 @@
#include <linux/sysctl.h>
#include <asm/smp.h>
-#include <asm/mtrr.h>
-#include <asm/mpspec.h>
+#include <asm/div64.h>
#include <asm/nmi.h>
#include "mach_traps.h"
@@ -324,6 +323,16 @@ static void clear_msr_range(unsigned int
wrmsr(base+i, 0, 0);
}
+static inline void write_watchdog_counter(const char *descr)
+{
+ u64 count = (u64)cpu_khz * 1000;
+
+ do_div(count, nmi_hz);
+ if(descr)
+ Dprintk("setting %s to -0x%08Lx\n", descr, count);
+ wrmsrl(nmi_perfctr_msr, 0 - count);
+}
+
static void setup_k7_watchdog(void)
{
unsigned int evntsel;
@@ -339,8 +348,7 @@ static void setup_k7_watchdog(void)
| K7_NMI_EVENT;
wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
- Dprintk("setting K7_PERFCTR0 to %08lx\n", -(cpu_khz/nmi_hz*1000));
- wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/nmi_hz*1000), -1);
+ write_watchdog_counter("K7_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= K7_EVNTSEL_ENABLE;
wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
@@ -361,8 +369,7 @@ static void setup_p6_watchdog(void)
| P6_NMI_EVENT;
wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
- Dprintk("setting P6_PERFCTR0 to %08lx\n", -(cpu_khz/nmi_hz*1000));
- wrmsr(MSR_P6_PERFCTR0, -(cpu_khz/nmi_hz*1000), 0);
+ write_watchdog_counter("P6_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= P6_EVNTSEL0_ENABLE;
wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
@@ -402,8 +409,7 @@ static int setup_p4_watchdog(void)
wrmsr(MSR_P4_CRU_ESCR0, P4_NMI_CRU_ESCR0, 0);
wrmsr(MSR_P4_IQ_CCCR0, P4_NMI_IQ_CCCR0 & ~P4_CCCR_ENABLE, 0);
- Dprintk("setting P4_IQ_COUNTER0 to 0x%08lx\n", -(cpu_khz/nmi_hz*1000));
- wrmsr(MSR_P4_IQ_COUNTER0, -(cpu_khz/nmi_hz*1000), -1);
+ write_watchdog_counter("P4_IQ_COUNTER0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
return 1;
@@ -518,7 +524,7 @@ void nmi_watchdog_tick (struct pt_regs *
* other P6 variant */
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
- wrmsr(nmi_perfctr_msr, -(cpu_khz/nmi_hz*1000), -1);
+ write_watchdog_counter(NULL);
}
}
(Note: Patch also attached because the inline version is certain to get
line wrapped.)
Get the i386 watchdog tick calculation into a state where it can also
be used on CPUs with frequencies beyond 4GHz, and it consolidates the
calculation into a single place (for potential furture adjustments).
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
diff -Npru linux-2.6.12-rc4.base/arch/i386/kernel/nmi.c linux-2.6.12-rc4/arch/i386/kernel/nmi.c
--- linux-2.6.12-rc4.base/arch/i386/kernel/nmi.c 2005-05-11 17:27:52.239252272 +0200
+++ linux-2.6.12-rc4/arch/i386/kernel/nmi.c 2005-05-11 17:50:36.249891136 +0200
@@ -28,8 +28,7 @@
#include <linux/sysctl.h>
#include <asm/smp.h>
-#include <asm/mtrr.h>
-#include <asm/mpspec.h>
+#include <asm/div64.h>
#include <asm/nmi.h>
#include "mach_traps.h"
@@ -324,6 +323,16 @@ static void clear_msr_range(unsigned int
wrmsr(base+i, 0, 0);
}
+static inline void write_watchdog_counter(const char *descr)
+{
+ u64 count = (u64)cpu_khz * 1000;
+
+ do_div(count, nmi_hz);
+ if(descr)
+ Dprintk("setting %s to -0x%08Lx\n", descr, count);
+ wrmsrl(nmi_perfctr_msr, 0 - count);
+}
+
static void setup_k7_watchdog(void)
{
unsigned int evntsel;
@@ -339,8 +348,7 @@ static void setup_k7_watchdog(void)
| K7_NMI_EVENT;
wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
- Dprintk("setting K7_PERFCTR0 to %08lx\n", -(cpu_khz/nmi_hz*1000));
- wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/nmi_hz*1000), -1);
+ write_watchdog_counter("K7_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= K7_EVNTSEL_ENABLE;
wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
@@ -361,8 +369,7 @@ static void setup_p6_watchdog(void)
| P6_NMI_EVENT;
wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
- Dprintk("setting P6_PERFCTR0 to %08lx\n", -(cpu_khz/nmi_hz*1000));
- wrmsr(MSR_P6_PERFCTR0, -(cpu_khz/nmi_hz*1000), 0);
+ write_watchdog_counter("P6_PERFCTR0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
evntsel |= P6_EVNTSEL0_ENABLE;
wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
@@ -402,8 +409,7 @@ static int setup_p4_watchdog(void)
wrmsr(MSR_P4_CRU_ESCR0, P4_NMI_CRU_ESCR0, 0);
wrmsr(MSR_P4_IQ_CCCR0, P4_NMI_IQ_CCCR0 & ~P4_CCCR_ENABLE, 0);
- Dprintk("setting P4_IQ_COUNTER0 to 0x%08lx\n", -(cpu_khz/nmi_hz*1000));
- wrmsr(MSR_P4_IQ_COUNTER0, -(cpu_khz/nmi_hz*1000), -1);
+ write_watchdog_counter("P4_IQ_COUNTER0");
apic_write(APIC_LVTPC, APIC_DM_NMI);
wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
return 1;
@@ -518,7 +524,7 @@ void nmi_watchdog_tick (struct pt_regs *
* other P6 variant */
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
- wrmsr(nmi_perfctr_msr, -(cpu_khz/nmi_hz*1000), -1);
+ write_watchdog_counter(NULL);
}
}