Merge branch 'tracing/core' into tracing/hw-breakpoints

Conflicts:
	arch/Kconfig
	kernel/trace/trace.h

Merge reason: resolve the conflicts, plus adopt to the new
              ring-buffer APIs.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 31 insertions, 14 deletions

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index ae3180c506a6..71f4368b357e 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -275,15 +275,20 @@ static unsigned long pit_calibrate_tsc(u32 latch, unsigned long ms, int loopmin)
  * use the TSC value at the transitions to calculate a pretty
  * good value for the TSC frequencty.
  */
+static inline int pit_verify_msb(unsigned char val)
+{
+        /* Ignore LSB */
+        inb(0x42);
+        return inb(0x42) == val;
+}
+
 static inline int pit_expect_msb(unsigned char val, u64 *tscp, unsigned long *deltap)
 {
         int count;
         u64 tsc = 0;
 
         for (count = 0; count < 50000; count++) {
-                /* Ignore LSB */
-                inb(0x42);
-                if (inb(0x42) != val)
+                if (!pit_verify_msb(val))
                         break;
                 tsc = get_cycles();
         }
@@ -336,8 +341,7 @@ static unsigned long quick_pit_calibrate(void)
          * to do that is to just read back the 16-bit counter
          * once from the PIT.
          */
-        inb(0x42);
-        inb(0x42);
+        pit_verify_msb(0);
 
         if (pit_expect_msb(0xff, &tsc, &d1)) {
                 for (i = 1; i <= MAX_QUICK_PIT_ITERATIONS; i++) {
@@ -348,8 +352,19 @@ static unsigned long quick_pit_calibrate(void)
                          * Iterate until the error is less than 500 ppm
                          */
                         delta -= tsc;
-                        if (d1+d2 < delta >> 11)
-                                goto success;
+                        if (d1+d2 >= delta >> 11)
+                                continue;
+
+                        /*
+                         * Check the PIT one more time to verify that
+                         * all TSC reads were stable wrt the PIT.
+                         *
+                         * This also guarantees serialization of the
+                         * last cycle read ('d2') in pit_expect_msb.
+                         */
+                        if (!pit_verify_msb(0xfe - i))
+                                break;
+                        goto success;
                 }
         }
         printk("Fast TSC calibration failed\n");
@@ -590,22 +605,26 @@ EXPORT_SYMBOL(recalibrate_cpu_khz);
  */
 
 DEFINE_PER_CPU(unsigned long, cyc2ns);
+DEFINE_PER_CPU(unsigned long long, cyc2ns_offset);
 
 static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
 {
-        unsigned long long tsc_now, ns_now;
+        unsigned long long tsc_now, ns_now, *offset;
         unsigned long flags, *scale;
 
         local_irq_save(flags);
         sched_clock_idle_sleep_event();
 
         scale = &per_cpu(cyc2ns, cpu);
+        offset = &per_cpu(cyc2ns_offset, cpu);
 
         rdtscll(tsc_now);
         ns_now = __cycles_2_ns(tsc_now);
 
-        if (cpu_khz)
+        if (cpu_khz) {
                 *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
+                *offset = ns_now - (tsc_now * *scale >> CYC2NS_SCALE_FACTOR);
+        }
 
         sched_clock_idle_wakeup_event(0);
         local_irq_restore(flags);
@@ -632,17 +651,15 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                                 void *data)
 {
         struct cpufreq_freqs *freq = data;
-        unsigned long *lpj, dummy;
+        unsigned long *lpj;
 
         if (cpu_has(&cpu_data(freq->cpu), X86_FEATURE_CONSTANT_TSC))
                 return 0;
 
-        lpj = &dummy;
-        if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+        lpj = &boot_cpu_data.loops_per_jiffy;
 #ifdef CONFIG_SMP
+        if (!(freq->flags & CPUFREQ_CONST_LOOPS))
                 lpj = &cpu_data(freq->cpu).loops_per_jiffy;
-#else
-        lpj = &boot_cpu_data.loops_per_jiffy;
 #endif
 
         if (!ref_freq) {