x86: merge tsc calibration

Merge the tsc calibration code for the 32bit and 64bit kernel.
The paravirtualized calculate_cpu_khz for 64bit now points to the correct
tsc_calibrate code as in 32bit.
Original native_calculate_cpu_khz for 64 bit is now called as calibrate_cpu.

Also moved the recalibrate_cpu_khz function in the common file.
Note that this function is called only from powernow K7 cpu freq driver.

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>

4 files changed, 153 insertions, 172 deletions

diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
index 39ae8511a137..c6ac4dad41f6 100644
--- a/arch/x86/kernel/time_64.c
+++ b/arch/x86/kernel/time_64.c
@@ -56,7 +56,7 @@ static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
 /* calibrate_cpu is used on systems with fixed rate TSCs to determine
  * processor frequency */
 #define TICK_COUNT 100000000
-unsigned long __init native_calculate_cpu_khz(void)
+static unsigned long __init calibrate_cpu(void)
 {
         int tsc_start, tsc_now;
         int i, no_ctr_free;
@@ -114,14 +114,18 @@ void __init hpet_time_init(void)
         setup_irq(0, &irq0);
 }
 
+extern void set_cyc2ns_scale(unsigned long cpu_khz, int cpu);
+
 void __init time_init(void)
 {
-        tsc_calibrate();
+        int cpu;
+
+        cpu_khz = calculate_cpu_khz();
+        tsc_khz = cpu_khz;
 
-        cpu_khz = tsc_khz;
         if (cpu_has(&boot_cpu_data, X86_FEATURE_CONSTANT_TSC) &&
-                (boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
-                cpu_khz = calculate_cpu_khz();
+                        (boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
+                cpu_khz = calibrate_cpu();
 
         lpj_fine = ((unsigned long)tsc_khz * 1000)/HZ;
 
@@ -134,7 +138,17 @@ void __init time_init(void)
                 vgetcpu_mode = VGETCPU_LSL;
 
         printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
-                cpu_khz / 1000, cpu_khz % 1000);
+                        cpu_khz / 1000, cpu_khz % 1000);
+
+        /*
+         * Secondary CPUs do not run through tsc_init(), so set up
+         * all the scale factors for all CPUs, assuming the same
+         * speed as the bootup CPU. (cpufreq notifiers will fix this
+         * up if their speed diverges)
+         */
+        for_each_possible_cpu(cpu)
+                set_cyc2ns_scale(cpu_khz, cpu);
+
         init_tsc_clocksource();
         late_time_init = choose_time_init();
 }
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 5d0be778fadd..e6ee14533c75 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1,7 +1,11 @@
+#include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/timer.h>
+#include <linux/acpi_pmtmr.h>
+
+#include <asm/hpet.h>
 
 unsigned int cpu_khz;           /* TSC clocks / usec, not used here */
 EXPORT_SYMBOL(cpu_khz);
@@ -84,3 +88,130 @@ int __init notsc_setup(char *str)
 #endif
 
 __setup("notsc", notsc_setup);
+
+#define MAX_RETRIES     5
+#define SMI_TRESHOLD    50000
+
+/*
+ * Read TSC and the reference counters. Take care of SMI disturbance
+ */
+static u64 __init tsc_read_refs(u64 *pm, u64 *hpet)
+{
+        u64 t1, t2;
+        int i;
+
+        for (i = 0; i < MAX_RETRIES; i++) {
+                t1 = get_cycles();
+                if (hpet)
+                        *hpet = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF;
+                else
+                        *pm = acpi_pm_read_early();
+                t2 = get_cycles();
+                if ((t2 - t1) < SMI_TRESHOLD)
+                        return t2;
+        }
+        return ULLONG_MAX;
+}
+
+/**
+ * tsc_calibrate - calibrate the tsc on boot
+ */
+static unsigned int __init tsc_calibrate(void)
+{
+        unsigned long flags;
+        u64 tsc1, tsc2, tr1, tr2, delta, pm1, pm2, hpet1, hpet2;
+        int hpet = is_hpet_enabled();
+        unsigned int tsc_khz_val = 0;
+
+        local_irq_save(flags);
+
+        tsc1 = tsc_read_refs(&pm1, hpet ? &hpet1 : NULL);
+
+        outb((inb(0x61) & ~0x02) | 0x01, 0x61);
+
+        outb(0xb0, 0x43);
+        outb((CLOCK_TICK_RATE / (1000 / 50)) & 0xff, 0x42);
+        outb((CLOCK_TICK_RATE / (1000 / 50)) >> 8, 0x42);
+        tr1 = get_cycles();
+        while ((inb(0x61) & 0x20) == 0);
+        tr2 = get_cycles();
+
+        tsc2 = tsc_read_refs(&pm2, hpet ? &hpet2 : NULL);
+
+        local_irq_restore(flags);
+
+        /*
+         * Preset the result with the raw and inaccurate PIT
+         * calibration value
+         */
+        delta = (tr2 - tr1);
+        do_div(delta, 50);
+        tsc_khz_val = delta;
+
+        /* hpet or pmtimer available ? */
+        if (!hpet && !pm1 && !pm2) {
+                printk(KERN_INFO "TSC calibrated against PIT\n");
+                goto out;
+        }
+
+        /* Check, whether the sampling was disturbed by an SMI */
+        if (tsc1 == ULLONG_MAX || tsc2 == ULLONG_MAX) {
+                printk(KERN_WARNING "TSC calibration disturbed by SMI, "
+                                "using PIT calibration result\n");
+                goto out;
+        }
+
+        tsc2 = (tsc2 - tsc1) * 1000000LL;
+
+        if (hpet) {
+                printk(KERN_INFO "TSC calibrated against HPET\n");
+                if (hpet2 < hpet1)
+                        hpet2 += 0x100000000ULL;
+                hpet2 -= hpet1;
+                tsc1 = ((u64)hpet2 * hpet_readl(HPET_PERIOD));
+                do_div(tsc1, 1000000);
+        } else {
+                printk(KERN_INFO "TSC calibrated against PM_TIMER\n");
+                if (pm2 < pm1)
+                        pm2 += (u64)ACPI_PM_OVRRUN;
+                pm2 -= pm1;
+                tsc1 = pm2 * 1000000000LL;
+                do_div(tsc1, PMTMR_TICKS_PER_SEC);
+        }
+
+        do_div(tsc2, tsc1);
+        tsc_khz_val = tsc2;
+
+out:
+        return tsc_khz_val;
+}
+
+unsigned long native_calculate_cpu_khz(void)
+{
+        return tsc_calibrate();
+}
+
+#ifdef CONFIG_X86_32
+/* Only called from the Powernow K7 cpu freq driver */
+int recalibrate_cpu_khz(void)
+{
+#ifndef CONFIG_SMP
+        unsigned long cpu_khz_old = cpu_khz;
+
+        if (cpu_has_tsc) {
+                cpu_khz = calculate_cpu_khz();
+                tsc_khz = cpu_khz;
+                cpu_data(0).loops_per_jiffy =
+                        cpufreq_scale(cpu_data(0).loops_per_jiffy,
+                                        cpu_khz_old, cpu_khz);
+                return 0;
+        } else
+                return -ENODEV;
+#else
+        return -ENODEV;
+#endif
+}
+
+EXPORT_SYMBOL(recalibrate_cpu_khz);
+
+#endif /* CONFIG_X86_32 */
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index dc8990056d75..40c0aafb358d 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -42,7 +42,7 @@ extern int tsc_disabled;
 
 DEFINE_PER_CPU(unsigned long, cyc2ns);
 
-static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
+void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
 {
         unsigned long long tsc_now, ns_now;
         unsigned long flags, *scale;
@@ -65,78 +65,6 @@ static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
         local_irq_restore(flags);
 }
 
-unsigned long native_calculate_cpu_khz(void)
-{
-        unsigned long long start, end;
-        unsigned long count;
-        u64 delta64 = (u64)ULLONG_MAX;
-        int i;
-        unsigned long flags;
-
-        local_irq_save(flags);
-
-        /* run 3 times to ensure the cache is warm and to get an accurate reading */
-        for (i = 0; i < 3; i++) {
-                mach_prepare_counter();
-                rdtscll(start);
-                mach_countup(&count);
-                rdtscll(end);
-
-                /*
-                 * Error: ECTCNEVERSET
-                 * The CTC wasn't reliable: we got a hit on the very first read,
-                 * or the CPU was so fast/slow that the quotient wouldn't fit in
-                 * 32 bits..
-                 */
-                if (count <= 1)
-                        continue;
-
-                /* cpu freq too slow: */
-                if ((end - start) <= CALIBRATE_TIME_MSEC)
-                        continue;
-
-                /*
-                 * We want the minimum time of all runs in case one of them
-                 * is inaccurate due to SMI or other delay
-                 */
-                delta64 = min(delta64, (end - start));
-        }
-
-        /* cpu freq too fast (or every run was bad): */
-        if (delta64 > (1ULL<<32))
-                goto err;
-
-        delta64 += CALIBRATE_TIME_MSEC/2; /* round for do_div */
-        do_div(delta64,CALIBRATE_TIME_MSEC);
-
-        local_irq_restore(flags);
-        return (unsigned long)delta64;
-err:
-        local_irq_restore(flags);
-        return 0;
-}
-
-int recalibrate_cpu_khz(void)
-{
-#ifndef CONFIG_SMP
-        unsigned long cpu_khz_old = cpu_khz;
-
-        if (cpu_has_tsc) {
-                cpu_khz = calculate_cpu_khz();
-                tsc_khz = cpu_khz;
-                cpu_data(0).loops_per_jiffy =
-                        cpufreq_scale(cpu_data(0).loops_per_jiffy,
-                                        cpu_khz_old, cpu_khz);
-                return 0;
-        } else
-                return -ENODEV;
-#else
-        return -ENODEV;
-#endif
-}
-
-EXPORT_SYMBOL(recalibrate_cpu_khz);
-
 #ifdef CONFIG_CPU_FREQ
 
 /*
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 69cbe4c9f050..c852ff9bd5d4 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -40,7 +40,7 @@ extern int tsc_disabled;
 
 DEFINE_PER_CPU(unsigned long, cyc2ns);
 
-static void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
+void set_cyc2ns_scale(unsigned long cpu_khz, int cpu)
 {
         unsigned long long tsc_now, ns_now;
         unsigned long flags, *scale;
@@ -130,98 +130,6 @@ core_initcall(cpufreq_tsc);
 
 #endif
 
-#define MAX_RETRIES     5
-#define SMI_TRESHOLD    50000
-
-/*
- * Read TSC and the reference counters. Take care of SMI disturbance
- */
-static unsigned long __init tsc_read_refs(unsigned long *pm,
-                                          unsigned long *hpet)
-{
-        unsigned long t1, t2;
-        int i;
-
-        for (i = 0; i < MAX_RETRIES; i++) {
-                t1 = get_cycles();
-                if (hpet)
-                        *hpet = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF;
-                else
-                        *pm = acpi_pm_read_early();
-                t2 = get_cycles();
-                if ((t2 - t1) < SMI_TRESHOLD)
-                        return t2;
-        }
-        return ULONG_MAX;
-}
-
-/**
- * tsc_calibrate - calibrate the tsc on boot
- */
-void __init tsc_calibrate(void)
-{
-        unsigned long flags, tsc1, tsc2, tr1, tr2, pm1, pm2, hpet1, hpet2;
-        int hpet = is_hpet_enabled(), cpu;
-
-        local_irq_save(flags);
-
-        tsc1 = tsc_read_refs(&pm1, hpet ? &hpet1 : NULL);
-
-        outb((inb(0x61) & ~0x02) | 0x01, 0x61);
-
-        outb(0xb0, 0x43);
-        outb((CLOCK_TICK_RATE / (1000 / 50)) & 0xff, 0x42);
-        outb((CLOCK_TICK_RATE / (1000 / 50)) >> 8, 0x42);
-        tr1 = get_cycles();
-        while ((inb(0x61) & 0x20) == 0);
-        tr2 = get_cycles();
-
-        tsc2 = tsc_read_refs(&pm2, hpet ? &hpet2 : NULL);
-
-        local_irq_restore(flags);
-
-        /*
-         * Preset the result with the raw and inaccurate PIT
-         * calibration value
-         */
-        tsc_khz = (tr2 - tr1) / 50;
-
-        /* hpet or pmtimer available ? */
-        if (!hpet && !pm1 && !pm2) {
-                printk(KERN_INFO "TSC calibrated against PIT\n");
-                goto out;
-        }
-
-        /* Check, whether the sampling was disturbed by an SMI */
-        if (tsc1 == ULONG_MAX || tsc2 == ULONG_MAX) {
-                printk(KERN_WARNING "TSC calibration disturbed by SMI, "
-                       "using PIT calibration result\n");
-                goto out;
-        }
-
-        tsc2 = (tsc2 - tsc1) * 1000000L;
-
-        if (hpet) {
-                printk(KERN_INFO "TSC calibrated against HPET\n");
-                if (hpet2 < hpet1)
-                        hpet2 += 0x100000000UL;
-                hpet2 -= hpet1;
-                tsc1 = (hpet2 * hpet_readl(HPET_PERIOD)) / 1000000;
-        } else {
-                printk(KERN_INFO "TSC calibrated against PM_TIMER\n");
-                if (pm2 < pm1)
-                        pm2 += ACPI_PM_OVRRUN;
-                pm2 -= pm1;
-                tsc1 = (pm2 * 1000000000) / PMTMR_TICKS_PER_SEC;
-        }
-
-        tsc_khz = tsc2 / tsc1;
-
-out:
-        for_each_possible_cpu(cpu)
-                set_cyc2ns_scale(tsc_khz, cpu);
-}
-
 /*
  * Make an educated guess if the TSC is trustworthy and synchronized
  * over all CPUs.