vdso/gettimeofday: Prepare helper functions for 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 argument of the helper functions with 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-v1-11-c1b5c69a166f@linutronix.de

Author: anna-marialx

lib/vdso/gettimeofday.c

@@ -17,12 +17,12 @@
 #endif
 
 #ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT
-static __always_inline bool vdso_delta_ok(const struct vdso_time_data *vd, u64 delta)
+static __always_inline bool vdso_delta_ok(const struct vdso_clock *vc, u64 delta)
 {
-	return delta < vd->max_cycles;
+	return delta < vc->max_cycles;
 }
 #else
-static __always_inline bool vdso_delta_ok(const struct vdso_time_data *vd, u64 delta)
+static __always_inline bool vdso_delta_ok(const struct vdso_clock *vc, u64 delta)
 {
 	return true;
 }
@@ -39,14 +39,14 @@ static __always_inline u64 vdso_shift_ns(u64 ns, u32 shift)
  * Default implementation which works for all sane clocksources. That
  * obviously excludes x86/TSC.
  */
-static __always_inline u64 vdso_calc_ns(const struct vdso_time_data *vd, u64 cycles, u64 base)
+static __always_inline u64 vdso_calc_ns(const struct vdso_clock *vc, u64 cycles, u64 base)
 {
-	u64 delta = (cycles - vd->cycle_last) & VDSO_DELTA_MASK(vd);
+	u64 delta = (cycles - vc->cycle_last) & VDSO_DELTA_MASK(vc);
 
-	if (likely(vdso_delta_ok(vd, delta)))
-		return vdso_shift_ns((delta * vd->mult) + base, vd->shift);
+	if (likely(vdso_delta_ok(vc, delta)))
+		return vdso_shift_ns((delta * vc->mult) + base, vc->shift);
 
-	return mul_u64_u32_add_u64_shr(delta, vd->mult, base, vd->shift);
+	return mul_u64_u32_add_u64_shr(delta, vc->mult, base, vc->shift);
 }
 #endif /* vdso_calc_ns */
 
@@ -58,9 +58,9 @@ static inline bool __arch_vdso_hres_capable(void)
 #endif
 
 #ifndef vdso_clocksource_ok
-static inline bool vdso_clocksource_ok(const struct vdso_time_data *vd)
+static inline bool vdso_clocksource_ok(const struct vdso_clock *vc)
 {
-	return vd->clock_mode != VDSO_CLOCKMODE_NONE;
+	return vc->clock_mode != VDSO_CLOCKMODE_NONE;
 }
 #endif