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-rw-r--r--include/linux/clocksource.h58
1 files changed, 55 insertions, 3 deletions
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 86d143db6523..65b7c41471c3 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -17,9 +17,11 @@
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/of.h>
+#include <linux/clocksource_ids.h>
#include <asm/div64.h>
#include <asm/io.h>
+struct clocksource_base;
struct clocksource;
struct module;
@@ -42,11 +44,15 @@ struct module;
* @shift: Cycle to nanosecond divisor (power of two)
* @max_idle_ns: Maximum idle time permitted by the clocksource (nsecs)
* @maxadj: Maximum adjustment value to mult (~11%)
+ * @uncertainty_margin: Maximum uncertainty in nanoseconds per half second.
+ * Zero says to use default WATCHDOG_THRESHOLD.
* @archdata: Optional arch-specific data
* @max_cycles: Maximum safe cycle value which won't overflow on
* multiplication
+ * @max_raw_delta: Maximum safe delta value for negative motion detection
* @name: Pointer to clocksource name
* @list: List head for registration (internal)
+ * @freq_khz: Clocksource frequency in khz.
* @rating: Rating value for selection (higher is better)
* To avoid rating inflation the following
* list should give you a guide as to how
@@ -62,7 +68,13 @@ struct module;
* 400-499: Perfect
* The ideal clocksource. A must-use where
* available.
+ * @id: Defaults to CSID_GENERIC. The id value is captured
+ * in certain snapshot functions to allow callers to
+ * validate the clocksource from which the snapshot was
+ * taken.
* @flags: Flags describing special properties
+ * @base: Hardware abstraction for clock on which a clocksource
+ * is based
* @enable: Optional function to enable the clocksource
* @disable: Optional function to disable the clocksource
* @suspend: Optional suspend function for the clocksource
@@ -70,7 +82,7 @@ struct module;
* @mark_unstable: Optional function to inform the clocksource driver that
* the watchdog marked the clocksource unstable
* @tick_stable: Optional function called periodically from the watchdog
- * code to provide stable syncrhonization points
+ * code to provide stable synchronization points
* @wd_list: List head to enqueue into the watchdog list (internal)
* @cs_last: Last clocksource value for clocksource watchdog
* @wd_last: Last watchdog value corresponding to @cs_last
@@ -93,15 +105,20 @@ struct clocksource {
u32 shift;
u64 max_idle_ns;
u32 maxadj;
+ u32 uncertainty_margin;
#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
struct arch_clocksource_data archdata;
#endif
u64 max_cycles;
+ u64 max_raw_delta;
const char *name;
struct list_head list;
+ u32 freq_khz;
int rating;
+ enum clocksource_ids id;
enum vdso_clock_mode vdso_clock_mode;
unsigned long flags;
+ struct clocksource_base *base;
int (*enable)(struct clocksource *cs);
void (*disable)(struct clocksource *cs);
@@ -131,7 +148,7 @@ struct clocksource {
#define CLOCK_SOURCE_UNSTABLE 0x40
#define CLOCK_SOURCE_SUSPEND_NONSTOP 0x80
#define CLOCK_SOURCE_RESELECT 0x100
-
+#define CLOCK_SOURCE_VERIFY_PERCPU 0x200
/* simplify initialization of mask field */
#define CLOCKSOURCE_MASK(bits) GENMASK_ULL((bits) - 1, 0)
@@ -200,7 +217,6 @@ static inline s64 clocksource_cyc2ns(u64 cycles, u32 mult, u32 shift)
extern int clocksource_unregister(struct clocksource*);
extern void clocksource_touch_watchdog(void);
-extern void clocksource_change_rating(struct clocksource *cs, int rating);
extern void clocksource_suspend(void);
extern void clocksource_resume(void);
extern struct clocksource * __init clocksource_default_clock(void);
@@ -282,4 +298,40 @@ static inline void timer_probe(void) {}
#define TIMER_ACPI_DECLARE(name, table_id, fn) \
ACPI_DECLARE_PROBE_ENTRY(timer, name, table_id, 0, NULL, 0, fn)
+static inline unsigned int clocksource_get_max_watchdog_retry(void)
+{
+ /*
+ * When system is in the boot phase or under heavy workload, there
+ * can be random big latencies during the clocksource/watchdog
+ * read, so allow retries to filter the noise latency. As the
+ * latency's frequency and maximum value goes up with the number of
+ * CPUs, scale the number of retries with the number of online
+ * CPUs.
+ */
+ return (ilog2(num_online_cpus()) / 2) + 1;
+}
+
+void clocksource_verify_percpu(struct clocksource *cs);
+
+/**
+ * struct clocksource_base - hardware abstraction for clock on which a clocksource
+ * is based
+ * @id: Defaults to CSID_GENERIC. The id value is used for conversion
+ * functions which require that the current clocksource is based
+ * on a clocksource_base with a particular ID in certain snapshot
+ * functions to allow callers to validate the clocksource from
+ * which the snapshot was taken.
+ * @freq_khz: Nominal frequency of the base clock in kHz
+ * @offset: Offset between the base clock and the clocksource
+ * @numerator: Numerator of the clock ratio between base clock and the clocksource
+ * @denominator: Denominator of the clock ratio between base clock and the clocksource
+ */
+struct clocksource_base {
+ enum clocksource_ids id;
+ u32 freq_khz;
+ u64 offset;
+ u32 numerator;
+ u32 denominator;
+};
+
#endif /* _LINUX_CLOCKSOURCE_H */