From: "Jan Beulich" 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 Signed-off-by: Andrew Morton --- arch/i386/kernel/nmi.c | 24 +++++++++++++++--------- 1 files changed, 15 insertions(+), 9 deletions(-) diff -puN arch/i386/kernel/nmi.c~adjust-i386-watchdog-tick-calculation arch/i386/kernel/nmi.c --- 25/arch/i386/kernel/nmi.c~adjust-i386-watchdog-tick-calculation 2005-05-13 22:23:41.000000000 -0700 +++ 25-akpm/arch/i386/kernel/nmi.c 2005-05-13 22:23:41.000000000 -0700 @@ -28,8 +28,7 @@ #include #include -#include -#include +#include #include #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); } } _