[PATCH] clocksource: Remove the update callback
Thomas Gleixner [Fri, 16 Feb 2007 09:27:42 +0000 (01:27 -0800)]
The clocksource code allows direct updates of the rating of a given
clocksource now.  Change TSC unstable tracking to use this interface and
remove the update callback.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/i386/kernel/tsc.c
include/linux/clocksource.h
kernel/timer.c

index a376549..b4b2be2 100644 (file)
@@ -60,12 +60,6 @@ static inline int check_tsc_unstable(void)
        return tsc_unstable;
 }
 
-void mark_tsc_unstable(void)
-{
-       tsc_unstable = 1;
-}
-EXPORT_SYMBOL_GPL(mark_tsc_unstable);
-
 /* Accellerators for sched_clock()
  * convert from cycles(64bits) => nanoseconds (64bits)
  *  basic equation:
@@ -295,7 +289,6 @@ core_initcall(cpufreq_tsc);
 /* clock source code */
 
 static unsigned long current_tsc_khz = 0;
-static int tsc_update_callback(void);
 
 static cycle_t read_tsc(void)
 {
@@ -313,37 +306,28 @@ static struct clocksource clocksource_tsc = {
        .mask                   = CLOCKSOURCE_MASK(64),
        .mult                   = 0, /* to be set */
        .shift                  = 22,
-       .update_callback        = tsc_update_callback,
        .flags                  = CLOCK_SOURCE_IS_CONTINUOUS |
                                  CLOCK_SOURCE_MUST_VERIFY,
 };
 
-static int tsc_update_callback(void)
+void mark_tsc_unstable(void)
 {
-       int change = 0;
-
-       /* check to see if we should switch to the safe clocksource: */
-       if (clocksource_tsc.rating != 0 && check_tsc_unstable()) {
-               clocksource_change_rating(&clocksource_tsc, 0);
-               change = 1;
-       }
-
-       /* only update if tsc_khz has changed: */
-       if (current_tsc_khz != tsc_khz) {
-               current_tsc_khz = tsc_khz;
-               clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
-                                                       clocksource_tsc.shift);
-               change = 1;
+       if (!tsc_unstable) {
+               tsc_unstable = 1;
+               /* Can be called before registration */
+               if (clocksource_tsc.mult)
+                       clocksource_change_rating(&clocksource_tsc, 0);
+               else
+                       clocksource_tsc.rating = 0;
        }
-
-       return change;
 }
+EXPORT_SYMBOL_GPL(mark_tsc_unstable);
 
 static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d)
 {
        printk(KERN_NOTICE "%s detected: marking TSC unstable.\n",
                       d->ident);
-       mark_tsc_unstable();
+       tsc_unstable = 1;
        return 0;
 }
 
@@ -415,11 +399,12 @@ __cpuinit int unsynchronized_tsc(void)
         * Intel systems are normally all synchronized.
         * Exceptions must mark TSC as unstable:
         */
-       if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
-               return 0;
-
-       /* assume multi socket systems are not synchronized: */
-       return num_possible_cpus() > 1;
+       if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
+               /* assume multi socket systems are not synchronized: */
+               if (num_possible_cpus() > 1)
+                       tsc_unstable = 1;
+       }
+       return tsc_unstable;
 }
 
 static int __init init_tsc_clocksource(void)
@@ -429,8 +414,7 @@ static int __init init_tsc_clocksource(void)
                /* check blacklist */
                dmi_check_system(bad_tsc_dmi_table);
 
-               if (unsynchronized_tsc()) /* mark unstable if unsynced */
-                       mark_tsc_unstable();
+               unsynchronized_tsc();
                current_tsc_khz = tsc_khz;
                clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
                                                        clocksource_tsc.shift);
index 45b0c31..a585a29 100644 (file)
@@ -44,7 +44,6 @@ typedef u64 cycle_t;
  *                     subtraction of non 64 bit counters
  * @mult:              cycle to nanosecond multiplier
  * @shift:             cycle to nanosecond divisor (power of two)
- * @update_callback:   called when safe to alter clocksource values
  * @flags:             flags describing special properties
  * @cycle_interval:    Used internally by timekeeping core, please ignore.
  * @xtime_interval:    Used internally by timekeeping core, please ignore.
@@ -57,7 +56,6 @@ struct clocksource {
        cycle_t mask;
        u32 mult;
        u32 shift;
-       int (*update_callback)(void);
        unsigned long flags;
 
        /* timekeeping specific data, ignore */
index 1144ff2..4b088fc 100644 (file)
@@ -848,8 +848,6 @@ static int change_clocksource(void)
                printk(KERN_INFO "Time: %s clocksource has been installed.\n",
                       clock->name);
                return 1;
-       } else if (clock->update_callback) {
-               return clock->update_callback();
        }
        return 0;
 }