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

…inux/kernel/git/tip/tip 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
kawasaki · Apr 2, 2018 · a553243 · a553243
2 parents cea061e + ea89c06
commit a553243
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Showing 5 changed files with 43 additions and 5 deletions.
diff --git a/arch/x86/events/msr.c b/arch/x86/events/msr.c
@@ -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;

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
@@ -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);

diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
@@ -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);

diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -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;

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
@@ -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);
 /**