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Commit 7e69f2b1 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Linus Torvalds
Browse files

[PATCH] clocksource: Remove the update callback 



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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 877fe380

arch/i386/kernel/tsc.c

+17 −33
Original line number Diff line number Diff line
@@ -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()) {

	if (!tsc_unstable) {

		tsc_unstable = 1;

		/* Can be called before registration */

		if (clocksource_tsc.mult)

			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;

		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;



	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {

		/* assume multi socket systems are not synchronized: */

 	return num_possible_cpus() > 1;

		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);

include/linux/clocksource.h

+0 −2
Original line number Diff line number Diff line
@@ -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 */

kernel/timer.c

+0 −2
Original line number Diff line number Diff line
@@ -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;

}