[PATCH] x86_64: watchdog frequency calculation adjustments

[Jan Beulich]

(Note: Patch also attached because the inline version is certain to get
line wrapped.)

Like previously done for i386, get the x86_64 watchdog tick
calculation
into a state where it can also be used on CPUs with frequencies beyond
4GHz.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

---
/home/jbeulich/tmp/linux-2.6.13/arch/x86_64/kernel/nmi.c	2005-08-29
01:41:01.000000000 +0200
+++ 2.6.13/arch/x86_64/kernel/nmi.c	2005-09-06 11:03:36.000000000
+0200
@@ -367,7 +367,7 @@ static void setup_k7_watchdog(void)
 		| K7_NMI_EVENT;
 
 	wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
-	wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/nmi_hz*1000), -1);
+	wrmsrl(MSR_K7_PERFCTR0, -((u64)cpu_khz * 1000 / nmi_hz));
 	apic_write(APIC_LVTPC, APIC_DM_NMI);
 	evntsel |= K7_EVNTSEL_ENABLE;
 	wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
@@ -408,8 +408,8 @@ 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);
+	Dprintk("setting P4_IQ_COUNTER0 to 0x%08lx\n", -(cpu_khz *
1000UL / nmi_hz));
+	wrmsrl(MSR_P4_IQ_COUNTER0, -((u64)cpu_khz * 1000 / nmi_hz));
 	apic_write(APIC_LVTPC, APIC_DM_NMI);
 	wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
 	return 1;
@@ -505,7 +505,7 @@ void nmi_watchdog_tick (struct pt_regs *
  			wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
  			apic_write(APIC_LVTPC, APIC_DM_NMI);
  		}
-		wrmsr(nmi_perfctr_msr, -(cpu_khz/nmi_hz*1000), -1);
+		wrmsrl(nmi_perfctr_msr, -((u64)cpu_khz * 1000 /
nmi_hz));
 	}
 }

Attachment: linux-2.6.13-x86_64-watchdog.patch
Description: Binary data