lib/vdso: Add vdso_data pointer as input to __arch_get_timens_vdso_data()

For the same reason as commit e876f0b69dc9 ("lib/vdso: Allow
architectures to provide the vdso data pointer"), powerpc wants to
avoid calculation of relative position to code.

As the timens_vdso_data is next page to vdso_data, provide
vdso_data pointer to __arch_get_timens_vdso_data() in order
to ease the calculation on powerpc in following patches.

Signed-off-by: Christophe Leroy <[e-mail]>
Reviewed-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Vincenzo Frascino <[e-mail]>
Acked-by: Andrei Vagin <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/539c4204[e-mail]

arch/arm64/include/asm/vdso/compat_gettimeofday.h

···
 }
 
 #ifdef CONFIG_TIME_NS
-static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
+static __always_inline
+const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
 {
 	const struct vdso_data *ret;
 

arch/arm64/include/asm/vdso/gettimeofday.h

···
 
 #ifdef CONFIG_TIME_NS
 static __always_inline
-const struct vdso_data *__arch_get_timens_vdso_data(void)
+const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
 {
 	return _timens_data;
 }

arch/s390/include/asm/vdso/gettimeofday.h

···
 }
 
 #ifdef CONFIG_TIME_NS
-static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
+static __always_inline
+const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
 {
 	return _timens_data;
 }

arch/x86/include/asm/vdso/gettimeofday.h

···
 #endif
 
 #ifdef CONFIG_TIME_NS
-static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
+static __always_inline
+const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
 {
 	return __timens_vdso_data;
 }

lib/vdso/gettimeofday.c

···
 static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 					  struct __kernel_timespec *ts)
 {
-	const struct vdso_data *vd = __arch_get_timens_vdso_data();
+	const struct vdso_data *vd;
 	const struct timens_offset *offs = &vdns->offset[clk];
 	const struct vdso_timestamp *vdso_ts;
 	u64 cycles, last, ns;
 	u32 seq;
 	s64 sec;
 
+	vd = vdns - (clk == CLOCK_MONOTONIC_RAW ? CS_RAW : CS_HRES_COARSE);
+	vd = __arch_get_timens_vdso_data(vd);
 	if (clk != CLOCK_MONOTONIC_RAW)
 		vd = &vd[CS_HRES_COARSE];
 	else
···
 	return 0;
 }
 #else
-static __always_inline const struct vdso_data *__arch_get_timens_vdso_data(void)
+static __always_inline
+const struct vdso_data *__arch_get_timens_vdso_data(const struct vdso_data *vd)
 {
 	return NULL;
 }
···
 static __always_inline int do_coarse_timens(const struct vdso_data *vdns, clockid_t clk,
 					    struct __kernel_timespec *ts)
 {
-	const struct vdso_data *vd = __arch_get_timens_vdso_data();
+	const struct vdso_data *vd = __arch_get_timens_vdso_data(vdns);
 	const struct vdso_timestamp *vdso_ts = &vd->basetime[clk];
 	const struct timens_offset *offs = &vdns->offset[clk];
 	u64 nsec;
···
 	if (unlikely(tz != NULL)) {
 		if (IS_ENABLED(CONFIG_TIME_NS) &&
 		    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
-			vd = __arch_get_timens_vdso_data();
+			vd = __arch_get_timens_vdso_data(vd);
 
 		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
 		tz->tz_dsttime = vd[CS_HRES_COARSE].tz_dsttime;
···
 
 	if (IS_ENABLED(CONFIG_TIME_NS) &&
 	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
-		vd = __arch_get_timens_vdso_data();
+		vd = __arch_get_timens_vdso_data(vd);
 
 	t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
 
···
 
 	if (IS_ENABLED(CONFIG_TIME_NS) &&
 	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
-		vd = __arch_get_timens_vdso_data();
+		vd = __arch_get_timens_vdso_data(vd);
 
 	/*
 	 * Convert the clockid to a bitmask and use it to check which