x86_64: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c
index 1242462..355f5f5 100644
--- a/arch/x86/kernel/tsc_sync.c
+++ b/arch/x86/kernel/tsc_sync.c
@@ -1 +1,187 @@
-#include "../../x86_64/kernel/tsc_sync.c"
+/*
+ * arch/x86_64/kernel/tsc_sync.c: check TSC synchronization.
+ *
+ * Copyright (C) 2006, Red Hat, Inc., Ingo Molnar
+ *
+ * We check whether all boot CPUs have their TSC's synchronized,
+ * print a warning if not and turn off the TSC clock-source.
+ *
+ * The warp-check is point-to-point between two CPUs, the CPU
+ * initiating the bootup is the 'source CPU', the freshly booting
+ * CPU is the 'target CPU'.
+ *
+ * Only two CPUs may participate - they can enter in any order.
+ * ( The serial nature of the boot logic and the CPU hotplug lock
+ * protects against more than 2 CPUs entering this code. )
+ */
+#include <linux/spinlock.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/nmi.h>
+#include <asm/tsc.h>
+
+/*
+ * Entry/exit counters that make sure that both CPUs
+ * run the measurement code at once:
+ */
+static __cpuinitdata atomic_t start_count;
+static __cpuinitdata atomic_t stop_count;
+
+/*
+ * We use a raw spinlock in this exceptional case, because
+ * we want to have the fastest, inlined, non-debug version
+ * of a critical section, to be able to prove TSC time-warps:
+ */
+static __cpuinitdata raw_spinlock_t sync_lock = __RAW_SPIN_LOCK_UNLOCKED;
+static __cpuinitdata cycles_t last_tsc;
+static __cpuinitdata cycles_t max_warp;
+static __cpuinitdata int nr_warps;
+
+/*
+ * TSC-warp measurement loop running on both CPUs:
+ */
+static __cpuinit void check_tsc_warp(void)
+{
+ cycles_t start, now, prev, end;
+ int i;
+
+ start = get_cycles_sync();
+ /*
+ * The measurement runs for 20 msecs:
+ */
+ end = start + tsc_khz * 20ULL;
+ now = start;
+
+ for (i = 0; ; i++) {
+ /*
+ * We take the global lock, measure TSC, save the
+ * previous TSC that was measured (possibly on
+ * another CPU) and update the previous TSC timestamp.
+ */
+ __raw_spin_lock(&sync_lock);
+ prev = last_tsc;
+ now = get_cycles_sync();
+ last_tsc = now;
+ __raw_spin_unlock(&sync_lock);
+
+ /*
+ * Be nice every now and then (and also check whether
+ * measurement is done [we also insert a 100 million
+ * loops safety exit, so we dont lock up in case the
+ * TSC readout is totally broken]):
+ */
+ if (unlikely(!(i & 7))) {
+ if (now > end || i > 100000000)
+ break;
+ cpu_relax();
+ touch_nmi_watchdog();
+ }
+ /*
+ * Outside the critical section we can now see whether
+ * we saw a time-warp of the TSC going backwards:
+ */
+ if (unlikely(prev > now)) {
+ __raw_spin_lock(&sync_lock);
+ max_warp = max(max_warp, prev - now);
+ nr_warps++;
+ __raw_spin_unlock(&sync_lock);
+ }
+
+ }
+}
+
+/*
+ * Source CPU calls into this - it waits for the freshly booted
+ * target CPU to arrive and then starts the measurement:
+ */
+void __cpuinit check_tsc_sync_source(int cpu)
+{
+ int cpus = 2;
+
+ /*
+ * No need to check if we already know that the TSC is not
+ * synchronized:
+ */
+ if (unsynchronized_tsc())
+ return;
+
+ printk(KERN_INFO "checking TSC synchronization [CPU#%d -> CPU#%d]:",
+ smp_processor_id(), cpu);
+
+ /*
+ * Reset it - in case this is a second bootup:
+ */
+ atomic_set(&stop_count, 0);
+
+ /*
+ * Wait for the target to arrive:
+ */
+ while (atomic_read(&start_count) != cpus-1)
+ cpu_relax();
+ /*
+ * Trigger the target to continue into the measurement too:
+ */
+ atomic_inc(&start_count);
+
+ check_tsc_warp();
+
+ while (atomic_read(&stop_count) != cpus-1)
+ cpu_relax();
+
+ /*
+ * Reset it - just in case we boot another CPU later:
+ */
+ atomic_set(&start_count, 0);
+
+ if (nr_warps) {
+ printk("\n");
+ printk(KERN_WARNING "Measured %Ld cycles TSC warp between CPUs,"
+ " turning off TSC clock.\n", max_warp);
+ mark_tsc_unstable("check_tsc_sync_source failed");
+ nr_warps = 0;
+ max_warp = 0;
+ last_tsc = 0;
+ } else {
+ printk(" passed.\n");
+ }
+
+ /*
+ * Let the target continue with the bootup:
+ */
+ atomic_inc(&stop_count);
+}
+
+/*
+ * Freshly booted CPUs call into this:
+ */
+void __cpuinit check_tsc_sync_target(void)
+{
+ int cpus = 2;
+
+ if (unsynchronized_tsc())
+ return;
+
+ /*
+ * Register this CPU's participation and wait for the
+ * source CPU to start the measurement:
+ */
+ atomic_inc(&start_count);
+ while (atomic_read(&start_count) != cpus)
+ cpu_relax();
+
+ check_tsc_warp();
+
+ /*
+ * Ok, we are done:
+ */
+ atomic_inc(&stop_count);
+
+ /*
+ * Wait for the source CPU to print stuff:
+ */
+ while (atomic_read(&stop_count) != cpus)
+ cpu_relax();
+}
+#undef NR_LOOPS
+
