From cf7a63ef4e0203f6f33284c69e8188d91422de83 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Thu, 19 Jul 2018 16:55:38 -0400 Subject: x86/tsc: Calibrate tsc only once During boot tsc is calibrated twice: once in tsc_early_delay_calibrate(), and the second time in tsc_init(). Rename tsc_early_delay_calibrate() to tsc_early_init(), and rework it so the calibration is done only early, and make tsc_init() to use the values already determined in tsc_early_init(). Sometimes it is not possible to determine tsc early, as the subsystem that is required is not yet initialized, in such case try again later in tsc_init(). Suggested-by: Thomas Gleixner Signed-off-by: Pavel Tatashin Signed-off-by: Thomas Gleixner Cc: steven.sistare@oracle.com Cc: daniel.m.jordan@oracle.com Cc: linux@armlinux.org.uk Cc: schwidefsky@de.ibm.com Cc: heiko.carstens@de.ibm.com Cc: john.stultz@linaro.org Cc: sboyd@codeaurora.org Cc: hpa@zytor.com Cc: douly.fnst@cn.fujitsu.com Cc: peterz@infradead.org Cc: prarit@redhat.com Cc: feng.tang@intel.com Cc: pmladek@suse.com Cc: gnomes@lxorguk.ukuu.org.uk Cc: linux-s390@vger.kernel.org Cc: boris.ostrovsky@oracle.com Cc: jgross@suse.com Cc: pbonzini@redhat.com Link: https://lkml.kernel.org/r/20180719205545.16512-20-pasha.tatashin@oracle.com --- arch/x86/include/asm/tsc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/include/asm/tsc.h') diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index 2701d221583a..c4368ff73652 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -33,7 +33,7 @@ static inline cycles_t get_cycles(void) extern struct system_counterval_t convert_art_to_tsc(u64 art); extern struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns); -extern void tsc_early_delay_calibrate(void); +extern void tsc_early_init(void); extern void tsc_init(void); extern void mark_tsc_unstable(char *reason); extern int unsynchronized_tsc(void); -- cgit v1.2.3