hrtimer: Add hrtimer support for CLOCK_TAI

Add hrtimer support for CLOCK_TAI, as well as posix timer interfaces.

Signed-off-by: John Stultz <[e-mail]>

include/linux/hrtimer.h

···
 	HRTIMER_BASE_MONOTONIC,
 	HRTIMER_BASE_REALTIME,
 	HRTIMER_BASE_BOOTTIME,
+	HRTIMER_BASE_TAI,
 	HRTIMER_MAX_CLOCK_BASES,
 };
 
···
 extern ktime_t ktime_get_real(void);
 extern ktime_t ktime_get_boottime(void);
 extern ktime_t ktime_get_monotonic_offset(void);
-extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot);
+extern ktime_t ktime_get_clocktai(void);
+extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot,
+					 ktime_t *offs_tai);
 
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 

include/linux/timekeeper_internal.h

···
 	struct timespec		raw_time;
 	/* The current UTC to TAI offset in seconds */
 	s32			tai_offset;
+	/* Offset clock monotonic -> clock tai */
+	ktime_t			offs_tai;
 
 	/* Seqlock for all timekeeper values */
 	seqlock_t		lock;

kernel/hrtimer.c

···
 			.get_time = &ktime_get_boottime,
 			.resolution = KTIME_LOW_RES,
 		},
+		{
+			.index = HRTIMER_BASE_TAI,
+			.clockid = CLOCK_TAI,
+			.get_time = &ktime_get_clocktai,
+			.resolution = KTIME_LOW_RES,
+		},
 	}
 };
 
···
 	[CLOCK_REALTIME]	= HRTIMER_BASE_REALTIME,
 	[CLOCK_MONOTONIC]	= HRTIMER_BASE_MONOTONIC,
 	[CLOCK_BOOTTIME]	= HRTIMER_BASE_BOOTTIME,
+	[CLOCK_TAI]		= HRTIMER_BASE_TAI,
 };
 
 static inline int hrtimer_clockid_to_base(clockid_t clock_id)
···
 {
 	ktime_t xtim, mono, boot;
 	struct timespec xts, tom, slp;
+	s32 tai_offset;
 
 	get_xtime_and_monotonic_and_sleep_offset(&xts, &tom, &slp);
+	tai_offset = timekeeping_get_tai_offset();
 
 	xtim = timespec_to_ktime(xts);
 	mono = ktime_add(xtim, timespec_to_ktime(tom));
···
 	base->clock_base[HRTIMER_BASE_REALTIME].softirq_time = xtim;
 	base->clock_base[HRTIMER_BASE_MONOTONIC].softirq_time = mono;
 	base->clock_base[HRTIMER_BASE_BOOTTIME].softirq_time = boot;
+	base->clock_base[HRTIMER_BASE_TAI].softirq_time =
+				ktime_add(xtim,	ktime_set(tai_offset, 0));
 }
 
 /*
···
 {
 	ktime_t *offs_real = &base->clock_base[HRTIMER_BASE_REALTIME].offset;
 	ktime_t *offs_boot = &base->clock_base[HRTIMER_BASE_BOOTTIME].offset;
+	ktime_t *offs_tai = &base->clock_base[HRTIMER_BASE_TAI].offset;
 
-	return ktime_get_update_offsets(offs_real, offs_boot);
+	return ktime_get_update_offsets(offs_real, offs_boot, offs_tai);
 }
 
 /*

kernel/posix-timers.c

···
 	struct k_clock clock_tai = {
 		.clock_getres	= hrtimer_get_res,
 		.clock_get	= posix_get_tai,
+		.nsleep		= common_nsleep,
+		.nsleep_restart	= hrtimer_nanosleep_restart,
+		.timer_create	= common_timer_create,
+		.timer_set	= common_timer_set,
+		.timer_get	= common_timer_get,
+		.timer_del	= common_timer_del,
 	};
 	struct k_clock clock_boottime = {
 		.clock_getres	= hrtimer_get_res,

kernel/time/timekeeping.c

···
 	tk->wall_to_monotonic = wtm;
 	set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
 	tk->offs_real = timespec_to_ktime(tmp);
+	tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0));
 }
 
 static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
···
 EXPORT_SYMBOL(timekeeping_clocktai);
 
 
+/**
+ * ktime_get_clocktai - Returns the TAI time of day in a ktime
+ *
+ * Returns the time of day in a ktime.
+ */
+ktime_t ktime_get_clocktai(void)
+{
+	struct timespec ts;
+
+	timekeeping_clocktai(&ts);
+	return timespec_to_ktime(ts);
+}
+EXPORT_SYMBOL(ktime_get_clocktai);
+
 #ifdef CONFIG_NTP_PPS
 
 /**
···
 void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
 {
 	tk->tai_offset = tai_offset;
+	tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0));
 }
 
 /**
···
  * Returns current monotonic time and updates the offsets
  * Called from hrtimer_interupt() or retrigger_next_event()
  */
-ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
+ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot,
+							ktime_t *offs_tai)
 {
 	struct timekeeper *tk = &timekeeper;
 	ktime_t now;
···
 
 		*offs_real = tk->offs_real;
 		*offs_boot = tk->offs_boot;
+		*offs_tai = tk->offs_tai;
 	} while (read_seqretry(&tk->lock, seq));
 
 	now = ktime_add_ns(ktime_set(secs, 0), nsecs);