[PATCH v3 06/18] x86/tsc: Use the full 64-bit tsc in tsc_delay

[Andy Lutomirski]

As a very minor optimization, tsc_delay was only using the low 32
bits of the TSC.  It's a delay function, so just use the whole
thing.

Signed-off-by: Andy Lutomirski <l...@kernel.org>
---
 arch/x86/lib/delay.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/x86/lib/delay.c b/arch/x86/lib/delay.c
index 9a52ad0c0758..35115f3786a9 100644
--- a/arch/x86/lib/delay.c
+++ b/arch/x86/lib/delay.c
@@ -49,16 +49,16 @@ static void delay_loop(unsigned long loops)
 /* TSC based delay: */
 static void delay_tsc(unsigned long __loops)
 {
-       u32 bclock, now, loops = __loops;
+       u64 bclock, now, loops = __loops;
        int cpu;
 
        preempt_disable();
        cpu = smp_processor_id();
        rdtsc_barrier();
-       rdtscl(bclock);
+       bclock = native_read_tsc();
        for (;;) {
                rdtsc_barrier();
-               rdtscl(now);
+               now = native_read_tsc();
                if ((now - bclock) >= loops)
                        break;
 
@@ -80,7 +80,7 @@ static void delay_tsc(unsigned long __loops)
                        loops -= (now - bclock);
                        cpu = smp_processor_id();
                        rdtsc_barrier();
-                       rdtscl(bclock);
+                       bclock = native_read_tsc();
                }
        }
        preempt_enable();
-- 
2.4.2

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