X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Ftsc_sync.c;h=bf36328f6ef9289c4b1a1a7d0ffd9c67878f3f32;hb=fa623d1b0222adbe8f822e53c08003b9679a410c;hp=9ffb01c31c40a8c9083e9949d065a442a62f46b7;hpb=8daa19051e1c7369c89ace7b18e74fe1f55dfa29;p=linux-2.6-omap-h63xx.git

diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c
index 9ffb01c31c4..bf36328f6ef 100644
--- a/arch/x86/kernel/tsc_sync.c
+++ b/arch/x86/kernel/tsc_sync.c
@@ -46,7 +46,9 @@ static __cpuinit void check_tsc_warp(void)
 	cycles_t start, now, prev, end;
 	int i;
 
+	rdtsc_barrier();
 	start = get_cycles();
+	rdtsc_barrier();
 	/*
 	 * The measurement runs for 20 msecs:
 	 */
@@ -61,7 +63,9 @@ static __cpuinit void check_tsc_warp(void)
 		 */
 		__raw_spin_lock(&sync_lock);
 		prev = last_tsc;
+		rdtsc_barrier();
 		now = get_cycles();
+		rdtsc_barrier();
 		last_tsc = now;
 		__raw_spin_unlock(&sync_lock);
 
@@ -108,6 +112,12 @@ void __cpuinit check_tsc_sync_source(int cpu)
 	if (unsynchronized_tsc())
 		return;
 
+	if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) {
+		printk(KERN_INFO
+		       "Skipping synchronization checks as TSC is reliable.\n");
+		return;
+	}
+
 	printk(KERN_INFO "checking TSC synchronization [CPU#%d -> CPU#%d]:",
 			  smp_processor_id(), cpu);
 
@@ -161,7 +171,7 @@ void __cpuinit check_tsc_sync_target(void)
 {
 	int cpus = 2;
 
-	if (unsynchronized_tsc())
+	if (unsynchronized_tsc() || boot_cpu_has(X86_FEATURE_TSC_RELIABLE))
 		return;
 
 	/*