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

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Pull x86 timer updates from Ingo Molnar:
 "Two changes: add the new convert_art_ns_to_tsc() API for upcoming
  Intel Goldmont+ drivers, and remove the obsolete rdtscll() API"

* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Get rid of rdtscll()
  x86/tsc: Convert ART in nanoseconds to TSC
This commit is contained in:
Linus Torvalds 2018-04-02 16:18:31 -07:00
commit a5532439eb
5 changed files with 43 additions and 5 deletions
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3
arch/x86/events/msr.c
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@ -188,10 +188,11 @@ static inline u64 msr_read_counter(struct perf_event *event)
if (event->hw.event_base)
rdmsrl(event->hw.event_base, now);
else
rdtscll(now);
now = rdtsc_ordered();
return now;
}
static void msr_event_update(struct perf_event *event)
{
u64 prev, now;

3
arch/x86/include/asm/msr.h
View File

@ -232,9 +232,6 @@ static __always_inline unsigned long long rdtsc_ordered(void)
return rdtsc();
}
/* Deprecated, keep it for a cycle for easier merging: */
#define rdtscll(now) do { (now) = rdtsc_ordered(); } while (0)
static inline unsigned long long native_read_pmc(int counter)
{
DECLARE_ARGS(val, low, high);

1
arch/x86/include/asm/tsc.h
View File

@ -31,6 +31,7 @@ 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_init(void);

2
arch/x86/kernel/cpu/mcheck/mce-inject.c
View File

@ -491,7 +491,7 @@ static void do_inject(void)
unsigned int cpu = i_mce.extcpu;
u8 b = i_mce.bank;
rdtscll(i_mce.tsc);
i_mce.tsc = rdtsc_ordered();
if (i_mce.misc)
i_mce.status |= MCI_STATUS_MISCV;

39
arch/x86/kernel/tsc.c
View File

@ -1179,6 +1179,45 @@ struct system_counterval_t convert_art_to_tsc(u64 art)
}
EXPORT_SYMBOL(convert_art_to_tsc);
/**
* convert_art_ns_to_tsc() - Convert ART in nanoseconds to TSC.
* @art_ns: ART (Always Running Timer) in unit of nanoseconds
*
* PTM requires all timestamps to be in units of nanoseconds. When user
* software requests a cross-timestamp, this function converts system timestamp
* to TSC.
*
* This is valid when CPU feature flag X86_FEATURE_TSC_KNOWN_FREQ is set
* indicating the tsc_khz is derived from CPUID[15H]. Drivers should check
* that this flag is set before conversion to TSC is attempted.
*
* Return:
* struct system_counterval_t - system counter value with the pointer to the
* corresponding clocksource
* @cycles: System counter value
* @cs: Clocksource corresponding to system counter value. Used
* by timekeeping code to verify comparibility of two cycle
* values.
*/
struct system_counterval_t convert_art_ns_to_tsc(u64 art_ns)
{
u64 tmp, res, rem;
rem = do_div(art_ns, USEC_PER_SEC);
res = art_ns * tsc_khz;
tmp = rem * tsc_khz;
do_div(tmp, USEC_PER_SEC);
res += tmp;
return (struct system_counterval_t) { .cs = art_related_clocksource,
.cycles = res};
}
EXPORT_SYMBOL(convert_art_ns_to_tsc);
static void tsc_refine_calibration_work(struct work_struct *work);
static DECLARE_DELAYED_WORK(tsc_irqwork, tsc_refine_calibration_work);
/**