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Commit 950b0d28 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86 

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
  x86: fix 64-bit asm NOPS for CONFIG_GENERIC_CPU
  x86: fix call to set_cyc2ns_scale() from time_cpufreq_notifier()
  revert "x86: tsc prevent time going backwards"
parents 2557a933 871de939

arch/x86/kernel/tsc_32.c

+2 −17
Original line number Diff line number Diff line
@@ -256,9 +256,7 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data) 
						ref_freq, freq->new);

			if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {

				tsc_khz = cpu_khz;

				preempt_disable();

				set_cyc2ns_scale(cpu_khz, smp_processor_id());

				preempt_enable();

				set_cyc2ns_scale(cpu_khz, freq->cpu);

				/*

				 * TSC based sched_clock turns

				 * to junk w/ cpufreq
@@ -287,27 +285,14 @@ core_initcall(cpufreq_tsc); 
/* clock source code */



static unsigned long current_tsc_khz = 0;

static struct clocksource clocksource_tsc;



/*

 * We compare the TSC to the cycle_last value in the clocksource

 * structure to avoid a nasty time-warp issue. This can be observed in

 * a very small window right after one CPU updated cycle_last under

 * xtime lock and the other CPU reads a TSC value which is smaller

 * than the cycle_last reference value due to a TSC which is slighty

 * behind. This delta is nowhere else observable, but in that case it

 * results in a forward time jump in the range of hours due to the

 * unsigned delta calculation of the time keeping core code, which is

 * necessary to support wrapping clocksources like pm timer.

 */

static cycle_t read_tsc(void)

{

	cycle_t ret;



	rdtscll(ret);



	return ret >= clocksource_tsc.cycle_last ?

		ret : clocksource_tsc.cycle_last;

	return ret;

}



static struct clocksource clocksource_tsc = {

arch/x86/kernel/tsc_64.c

+4 −23
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#include <asm/hpet.h>

#include <asm/timex.h>

#include <asm/timer.h>

#include <asm/vgtod.h>



static int notsc __initdata = 0;
@@ -149,9 +148,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, 
			mark_tsc_unstable("cpufreq changes");

	}



	preempt_disable();

	set_cyc2ns_scale(tsc_khz_ref, smp_processor_id());

	preempt_enable();

	set_cyc2ns_scale(tsc_khz_ref, freq->cpu);



	return 0;

}
@@ -291,34 +288,18 @@ int __init notsc_setup(char *s) 


__setup("notsc", notsc_setup);



static struct clocksource clocksource_tsc;



/*

 * We compare the TSC to the cycle_last value in the clocksource

 * structure to avoid a nasty time-warp. This can be observed in a

 * very small window right after one CPU updated cycle_last under

 * xtime/vsyscall_gtod lock and the other CPU reads a TSC value which

 * is smaller than the cycle_last reference value due to a TSC which

 * is slighty behind. This delta is nowhere else observable, but in

 * that case it results in a forward time jump in the range of hours

 * due to the unsigned delta calculation of the time keeping core

 * code, which is necessary to support wrapping clocksources like pm

 * timer.

 */

/* clock source code: */

static cycle_t read_tsc(void)

{

	cycle_t ret = (cycle_t)get_cycles();



	return ret >= clocksource_tsc.cycle_last ?

		ret : clocksource_tsc.cycle_last;

	return ret;

}



static cycle_t __vsyscall_fn vread_tsc(void)

{

	cycle_t ret = (cycle_t)vget_cycles();



	return ret >= __vsyscall_gtod_data.clock.cycle_last ?

		ret : __vsyscall_gtod_data.clock.cycle_last;

	return ret;

}



static struct clocksource clocksource_tsc = {

include/asm-x86/nops.h

+10 −10
Original line number Diff line number Diff line
@@ -73,16 +73,7 @@ 
#define P6_NOP7	".byte 0x0f,0x1f,0x80,0,0,0,0\n"

#define P6_NOP8	".byte 0x0f,0x1f,0x84,0x00,0,0,0,0\n"



#if defined(CONFIG_MK8)

#define ASM_NOP1 K8_NOP1

#define ASM_NOP2 K8_NOP2

#define ASM_NOP3 K8_NOP3

#define ASM_NOP4 K8_NOP4

#define ASM_NOP5 K8_NOP5

#define ASM_NOP6 K8_NOP6

#define ASM_NOP7 K8_NOP7

#define ASM_NOP8 K8_NOP8

#elif defined(CONFIG_MK7)

#if defined(CONFIG_MK7)

#define ASM_NOP1 K7_NOP1

#define ASM_NOP2 K7_NOP2

#define ASM_NOP3 K7_NOP3
@@ -100,6 +91,15 @@ 
#define ASM_NOP6 P6_NOP6

#define ASM_NOP7 P6_NOP7

#define ASM_NOP8 P6_NOP8

#elif defined(CONFIG_X86_64)

#define ASM_NOP1 K8_NOP1

#define ASM_NOP2 K8_NOP2

#define ASM_NOP3 K8_NOP3

#define ASM_NOP4 K8_NOP4

#define ASM_NOP5 K8_NOP5

#define ASM_NOP6 K8_NOP6

#define ASM_NOP7 K8_NOP7

#define ASM_NOP8 K8_NOP8

#else

#define ASM_NOP1 GENERIC_NOP1

#define ASM_NOP2 GENERIC_NOP2