vdso/vsyscall: Prepare introduction of struct vdso_clock

To support multiple PTP clocks, the VDSO data structure needs to be
reworked. All clock specific data will end up in struct vdso_clock and in
struct vdso_time_data there will be array of VDSO clocks. At the moment,
vdso_clock is simply a define which maps vdso_clock to vdso_time_data.

To prepare for the rework of the data structures, replace the struct
vdso_time_data pointer with a struct vdso_clock pointer where applicable.

No functional change.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250303-vdso-clock-v1-12-c1b5c69a166f@linutronix.de

1 files changed, 21 insertions, 19 deletions

diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index 418192296ef7..dd85b41a70be 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -18,25 +18,26 @@
 static inline void update_vdso_time_data(struct vdso_time_data *vdata, struct timekeeper *tk)
 {
 	struct vdso_timestamp *vdso_ts;
+	struct vdso_clock *vc = vdata;
 	u64 nsec, sec;
 
-	vdata[CS_HRES_COARSE].cycle_last	= tk->tkr_mono.cycle_last;
+	vc[CS_HRES_COARSE].cycle_last	= tk->tkr_mono.cycle_last;
 #ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT
-	vdata[CS_HRES_COARSE].max_cycles	= tk->tkr_mono.clock->max_cycles;
+	vc[CS_HRES_COARSE].max_cycles	= tk->tkr_mono.clock->max_cycles;
 #endif
-	vdata[CS_HRES_COARSE].mask		= tk->tkr_mono.mask;
-	vdata[CS_HRES_COARSE].mult		= tk->tkr_mono.mult;
-	vdata[CS_HRES_COARSE].shift		= tk->tkr_mono.shift;
-	vdata[CS_RAW].cycle_last		= tk->tkr_raw.cycle_last;
+	vc[CS_HRES_COARSE].mask		= tk->tkr_mono.mask;
+	vc[CS_HRES_COARSE].mult		= tk->tkr_mono.mult;
+	vc[CS_HRES_COARSE].shift	= tk->tkr_mono.shift;
+	vc[CS_RAW].cycle_last		= tk->tkr_raw.cycle_last;
 #ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT
-	vdata[CS_RAW].max_cycles		= tk->tkr_raw.clock->max_cycles;
+	vc[CS_RAW].max_cycles		= tk->tkr_raw.clock->max_cycles;
 #endif
-	vdata[CS_RAW].mask			= tk->tkr_raw.mask;
-	vdata[CS_RAW].mult			= tk->tkr_raw.mult;
-	vdata[CS_RAW].shift			= tk->tkr_raw.shift;
+	vc[CS_RAW].mask			= tk->tkr_raw.mask;
+	vc[CS_RAW].mult			= tk->tkr_raw.mult;
+	vc[CS_RAW].shift		= tk->tkr_raw.shift;
 
 	/* CLOCK_MONOTONIC */
-	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
+	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC];
 	vdso_ts->sec	= tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
 
 	nsec = tk->tkr_mono.xtime_nsec;
@@ -54,7 +55,7 @@ static inline void update_vdso_time_data(struct vdso_time_data *vdata, struct ti
 	nsec	+= (u64)tk->monotonic_to_boot.tv_nsec << tk->tkr_mono.shift;
 
 	/* CLOCK_BOOTTIME */
-	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
+	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_BOOTTIME];
 	vdso_ts->sec	= sec;
 
 	while (nsec >= (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
@@ -64,12 +65,12 @@ static inline void update_vdso_time_data(struct vdso_time_data *vdata, struct ti
 	vdso_ts->nsec	= nsec;
 
 	/* CLOCK_MONOTONIC_RAW */
-	vdso_ts		= &vdata[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
+	vdso_ts		= &vc[CS_RAW].basetime[CLOCK_MONOTONIC_RAW];
 	vdso_ts->sec	= tk->raw_sec;
 	vdso_ts->nsec	= tk->tkr_raw.xtime_nsec;
 
 	/* CLOCK_TAI */
-	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_TAI];
+	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_TAI];
 	vdso_ts->sec	= tk->xtime_sec + (s64)tk->tai_offset;
 	vdso_ts->nsec	= tk->tkr_mono.xtime_nsec;
 }
@@ -78,6 +79,7 @@ void update_vsyscall(struct timekeeper *tk)
 {
 	struct vdso_time_data *vdata = vdso_k_time_data;
 	struct vdso_timestamp *vdso_ts;
+	struct vdso_clock *vc = vdata;
 	s32 clock_mode;
 	u64 nsec;
 
@@ -85,21 +87,21 @@ void update_vsyscall(struct timekeeper *tk)
 	vdso_write_begin(vdata);
 
 	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
-	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
-	vdata[CS_RAW].clock_mode		= clock_mode;
+	vc[CS_HRES_COARSE].clock_mode	= clock_mode;
+	vc[CS_RAW].clock_mode		= clock_mode;
 
 	/* CLOCK_REALTIME also required for time() */
-	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
+	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
 	vdso_ts->sec	= tk->xtime_sec;
 	vdso_ts->nsec	= tk->tkr_mono.xtime_nsec;
 
 	/* CLOCK_REALTIME_COARSE */
-	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
+	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_REALTIME_COARSE];
 	vdso_ts->sec	= tk->xtime_sec;
 	vdso_ts->nsec	= tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
 
 	/* CLOCK_MONOTONIC_COARSE */
-	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
+	vdso_ts		= &vc[CS_HRES_COARSE].basetime[CLOCK_MONOTONIC_COARSE];
 	vdso_ts->sec	= tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
 	nsec		= tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
 	nsec		= nsec + tk->wall_to_monotonic.tv_nsec;