x86/tsc: Consolidate init code

Split out suplicated code from tsc_early_init() and tsc_init() into a
common helper and fixup some comment typos.

[ tglx: Massaged changelog and renamed function ]

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180730075421.22830-2-douly.fnst@cn.fujitsu.com

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 02e416b..1463468 100644 (file)
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -182,7 +182,7 @@ static void __init cyc2ns_init_boot_cpu(void)
 }
 
 /*
- * Secondary CPUs do not run through cyc2ns_init(), so set up
+ * 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)
@@ -1389,7 +1389,7 @@ static bool __init determine_cpu_tsc_frequencies(bool early)
        }
 
        /*
-        * Trust non-zero tsc_khz as authorative,
+        * Trust non-zero tsc_khz as authoritative,
         * and use it to sanity check cpu_khz,
         * which will be off if system timer is off.
         */
@@ -1421,6 +1421,14 @@ static unsigned long __init get_loops_per_jiffy(void)
        return lpj;
 }
 
+static void __init tsc_enable_sched_clock(void)
+{
+       /* Sanitize TSC ADJUST before cyc2ns gets initialized */
+       tsc_store_and_check_tsc_adjust(true);
+       cyc2ns_init_boot_cpu();
+       static_branch_enable(&__use_tsc);
+}
+
 void __init tsc_early_init(void)
 {
        if (!boot_cpu_has(X86_FEATURE_TSC))
@@ -1429,10 +1437,7 @@ void __init tsc_early_init(void)
                return;
        loops_per_jiffy = get_loops_per_jiffy();
 
-       /* Sanitize TSC ADJUST before cyc2ns gets initialized */
-       tsc_store_and_check_tsc_adjust(true);
-       cyc2ns_init_boot_cpu();
-       static_branch_enable(&__use_tsc);
+       tsc_enable_sched_clock();
 }
 
 void __init tsc_init(void)
@@ -1456,13 +1461,10 @@ void __init tsc_init(void)
                        setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER);
                        return;
                }
-               /* Sanitize TSC ADJUST before cyc2ns gets initialized */
-               tsc_store_and_check_tsc_adjust(true);
-               cyc2ns_init_boot_cpu();
+               tsc_enable_sched_clock();
        }
 
        cyc2ns_init_secondary_cpus();
-       static_branch_enable(&__use_tsc);
 
        if (!no_sched_irq_time)
                enable_sched_clock_irqtime();