x86: merge the TSC cpu-freq code

Unify the TSC cpufreq code.

Signed-off-by: Alok N Kataria <akataria@vmware.com>
Signed-off-by: Dan Hecht <dhecht@vmware.com>
Cc: Dan Hecht <dhecht@vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index e6ee14533c75d1c3c26838cc385c7f044d03c641..595f78a2221285906c15130879f243182a47f805 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -4,6 +4,7 @@
 #include <linux/module.h>
 #include <linux/timer.h>
 #include <linux/acpi_pmtmr.h>
+#include <linux/cpufreq.h>
 
 #include <asm/hpet.h>
 
@@ -215,3 +216,116 @@ int recalibrate_cpu_khz(void)
 EXPORT_SYMBOL(recalibrate_cpu_khz);
 
 #endif /* CONFIG_X86_32 */
+
+/* Accelerators for sched_clock()
+ * convert from cycles(64bits) => nanoseconds (64bits)
+ *  basic equation:
+ *              ns = cycles / (freq / ns_per_sec)
+ *              ns = cycles * (ns_per_sec / freq)
+ *              ns = cycles * (10^9 / (cpu_khz * 10^3))
+ *              ns = cycles * (10^6 / cpu_khz)
+ *
+ *      Then we use scaling math (suggested by george@mvista.com) to get:
+ *              ns = cycles * (10^6 * SC / cpu_khz) / SC
+ *              ns = cycles * cyc2ns_scale / SC
+ *
+ *      And since SC is a constant power of two, we can convert the div
+ *  into a shift.
+ *
+ *  We can use khz divisor instead of mhz to keep a better precision, since
+ *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
+ *  (mathieu.desnoyers@polymtl.ca)
+ *
+ *                      -johnstul@us.ibm.com "math is hard, lets go shopping!"
+ */
+
+DEFINE_PER_CPU(unsigned long, cyc2ns);
+
+void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
+{
+       unsigned long long tsc_now, ns_now;
+       unsigned long flags, *scale;
+
+       local_irq_save(flags);
+       sched_clock_idle_sleep_event();
+
+       scale = &per_cpu(cyc2ns, cpu);
+
+       rdtscll(tsc_now);
+       ns_now = __cycles_2_ns(tsc_now);
+
+       if (cpu_khz)
+               *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
+
+       sched_clock_idle_wakeup_event(0);
+       local_irq_restore(flags);
+}
+
+#ifdef CONFIG_CPU_FREQ
+
+/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
+ * changes.
+ *
+ * RED-PEN: On SMP we assume all CPUs run with the same frequency.  It's
+ * not that important because current Opteron setups do not support
+ * scaling on SMP anyroads.
+ *
+ * Should fix up last_tsc too. Currently gettimeofday in the
+ * first tick after the change will be slightly wrong.
+ */
+
+static unsigned int  ref_freq;
+static unsigned long loops_per_jiffy_ref;
+static unsigned long tsc_khz_ref;
+
+static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+                               void *data)
+{
+       struct cpufreq_freqs *freq = data;
+       unsigned long *lpj, dummy;
+
+       if (cpu_has(&cpu_data(freq->cpu), X86_FEATURE_CONSTANT_TSC))
+               return 0;
+
+       lpj = &dummy;
+       if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+#ifdef CONFIG_SMP
+               lpj = &cpu_data(freq->cpu).loops_per_jiffy;
+#else
+       lpj = &boot_cpu_data.loops_per_jiffy;
+#endif
+
+       if (!ref_freq) {
+               ref_freq = freq->old;
+               loops_per_jiffy_ref = *lpj;
+               tsc_khz_ref = tsc_khz;
+       }
+       if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
+                       (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
+                       (val == CPUFREQ_RESUMECHANGE)) {
+               *lpj =  cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
+
+               tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new);
+               if (!(freq->flags & CPUFREQ_CONST_LOOPS))
+                       mark_tsc_unstable("cpufreq changes");
+       }
+
+       set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
+
+       return 0;
+}
+
+static struct notifier_block time_cpufreq_notifier_block = {
+       .notifier_call  = time_cpufreq_notifier
+};
+
+static int __init cpufreq_tsc(void)
+{
+       cpufreq_register_notifier(&time_cpufreq_notifier_block,
+                               CPUFREQ_TRANSITION_NOTIFIER);
+       return 0;
+}
+
+core_initcall(cpufreq_tsc);
+
+#endif /* CONFIG_CPU_FREQ */

diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index 40c0aafb358dcc139103e71034eb8d6e9dfaeb2e..bbc153d36f84eeb3eaa6001d5ac088563ccf2015 100644 (file)
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -18,119 +18,6 @@
 extern int tsc_unstable;
 extern int tsc_disabled;
 
-/* Accelerators for sched_clock()
- * convert from cycles(64bits) => nanoseconds (64bits)
- *  basic equation:
- *             ns = cycles / (freq / ns_per_sec)
- *             ns = cycles * (ns_per_sec / freq)
- *             ns = cycles * (10^9 / (cpu_khz * 10^3))
- *             ns = cycles * (10^6 / cpu_khz)
- *
- *     Then we use scaling math (suggested by george@mvista.com) to get:
- *             ns = cycles * (10^6 * SC / cpu_khz) / SC
- *             ns = cycles * cyc2ns_scale / SC
- *
- *     And since SC is a constant power of two, we can convert the div
- *  into a shift.
- *
- *  We can use khz divisor instead of mhz to keep a better precision, since
- *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
- *  (mathieu.desnoyers@polymtl.ca)
- *
- *                     -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-
-DEFINE_PER_CPU(unsigned long, cyc2ns);
-
-void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
-{
-       unsigned long long tsc_now, ns_now;
-       unsigned long flags, *scale;
-
-       local_irq_save(flags);
-       sched_clock_idle_sleep_event();
-
-       scale = &per_cpu(cyc2ns, cpu);
-
-       rdtscll(tsc_now);
-       ns_now = __cycles_2_ns(tsc_now);
-
-       if (cpu_khz)
-               *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
-
-       /*
-        * Start smoothly with the new frequency:
-        */
-       sched_clock_idle_wakeup_event(0);
-       local_irq_restore(flags);
-}
-
-#ifdef CONFIG_CPU_FREQ
-
-/*
- * if the CPU frequency is scaled, TSC-based delays will need a different
- * loops_per_jiffy value to function properly.
- */
-static unsigned int ref_freq;
-static unsigned long loops_per_jiffy_ref;
-static unsigned long cpu_khz_ref;
-
-static int
-time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
-{
-       struct cpufreq_freqs *freq = data;
-
-       if (!ref_freq) {
-               if (!freq->old){
-                       ref_freq = freq->new;
-                       return 0;
-               }
-               ref_freq = freq->old;
-               loops_per_jiffy_ref = cpu_data(freq->cpu).loops_per_jiffy;
-               cpu_khz_ref = cpu_khz;
-       }
-
-       if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
-           (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
-           (val == CPUFREQ_RESUMECHANGE)) {
-               if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-                       cpu_data(freq->cpu).loops_per_jiffy =
-                               cpufreq_scale(loops_per_jiffy_ref,
-                                               ref_freq, freq->new);
-
-               if (cpu_khz) {
-
-                       if (num_online_cpus() == 1)
-                               cpu_khz = cpufreq_scale(cpu_khz_ref,
-                                               ref_freq, freq->new);
-                       if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
-                               tsc_khz = cpu_khz;
-                               set_cyc2ns_scale(cpu_khz, freq->cpu);
-                               /*
-                                * TSC based sched_clock turns
-                                * to junk w/ cpufreq
-                                */
-                               mark_tsc_unstable("cpufreq changes");
-                       }
-               }
-       }
-
-       return 0;
-}
-
-static struct notifier_block time_cpufreq_notifier_block = {
-       .notifier_call  = time_cpufreq_notifier
-};
-
-static int __init cpufreq_tsc(void)
-{
-       return cpufreq_register_notifier(&time_cpufreq_notifier_block,
-                                        CPUFREQ_TRANSITION_NOTIFIER);
-}
-core_initcall(cpufreq_tsc);
-
-#endif
-
 /* clock source code */
 
 static struct clocksource clocksource_tsc;

diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index c852ff9bd5d4f567292be0fbce0c2362edd1ddb4..80a274b018c28b02f88798deafe771e8b4c5b47f 100644 (file)
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -16,120 +16,6 @@
 extern int tsc_unstable;
 extern int tsc_disabled;
 
-/* Accelerators for sched_clock()
- * convert from cycles(64bits) => nanoseconds (64bits)
- *  basic equation:
- *             ns = cycles / (freq / ns_per_sec)
- *             ns = cycles * (ns_per_sec / freq)
- *             ns = cycles * (10^9 / (cpu_khz * 10^3))
- *             ns = cycles * (10^6 / cpu_khz)
- *
- *     Then we use scaling math (suggested by george@mvista.com) to get:
- *             ns = cycles * (10^6 * SC / cpu_khz) / SC
- *             ns = cycles * cyc2ns_scale / SC
- *
- *     And since SC is a constant power of two, we can convert the div
- *  into a shift.
- *
- *  We can use khz divisor instead of mhz to keep a better precision, since
- *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
- *  (mathieu.desnoyers@polymtl.ca)
- *
- *                     -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-
-DEFINE_PER_CPU(unsigned long, cyc2ns);
-
-void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
-{
-       unsigned long long tsc_now, ns_now;
-       unsigned long flags, *scale;
-
-       local_irq_save(flags);
-       sched_clock_idle_sleep_event();
-
-       scale = &per_cpu(cyc2ns, cpu);
-
-       rdtscll(tsc_now);
-       ns_now = __cycles_2_ns(tsc_now);
-
-       if (cpu_khz)
-               *scale = (NSEC_PER_MSEC << CYC2NS_SCALE_FACTOR)/cpu_khz;
-
-       sched_clock_idle_wakeup_event(0);
-       local_irq_restore(flags);
-}
-
-#ifdef CONFIG_CPU_FREQ
-
-/* Frequency scaling support. Adjust the TSC based timer when the cpu frequency
- * changes.
- *
- * RED-PEN: On SMP we assume all CPUs run with the same frequency.  It's
- * not that important because current Opteron setups do not support
- * scaling on SMP anyroads.
- *
- * Should fix up last_tsc too. Currently gettimeofday in the
- * first tick after the change will be slightly wrong.
- */
-
-static unsigned int  ref_freq;
-static unsigned long loops_per_jiffy_ref;
-static unsigned long tsc_khz_ref;
-
-static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
-                                void *data)
-{
-       struct cpufreq_freqs *freq = data;
-       unsigned long *lpj, dummy;
-
-       if (cpu_has(&cpu_data(freq->cpu), X86_FEATURE_CONSTANT_TSC))
-               return 0;
-
-       lpj = &dummy;
-       if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-#ifdef CONFIG_SMP
-               lpj = &cpu_data(freq->cpu).loops_per_jiffy;
-#else
-               lpj = &boot_cpu_data.loops_per_jiffy;
-#endif
-
-       if (!ref_freq) {
-               ref_freq = freq->old;
-               loops_per_jiffy_ref = *lpj;
-               tsc_khz_ref = tsc_khz;
-       }
-       if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
-               (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||
-               (val == CPUFREQ_RESUMECHANGE)) {
-               *lpj =
-               cpufreq_scale(loops_per_jiffy_ref, ref_freq, freq->new);
-
-               tsc_khz = cpufreq_scale(tsc_khz_ref, ref_freq, freq->new);
-               if (!(freq->flags & CPUFREQ_CONST_LOOPS))
-                       mark_tsc_unstable("cpufreq changes");
-       }
-
-       set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
-
-       return 0;
-}
-
-static struct notifier_block time_cpufreq_notifier_block = {
-       .notifier_call  = time_cpufreq_notifier
-};
-
-static int __init cpufreq_tsc(void)
-{
-       cpufreq_register_notifier(&time_cpufreq_notifier_block,
-                                 CPUFREQ_TRANSITION_NOTIFIER);
-       return 0;
-}
-
-core_initcall(cpufreq_tsc);
-
-#endif
-
 /*
  * Make an educated guess if the TSC is trustworthy and synchronized
  * over all CPUs.