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

For the same reason as commit e876f0b6 ("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 <christophe.leroy@csgroup.eu>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/539c4204b1baa77c55f758904a1ea239abbc7a5c.1617209142.git.christophe.leroy@csgroup.eu

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

@@ -155,7 +155,8 @@ static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
 }
 
 #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

@@ -100,7 +100,7 @@ const struct vdso_data *__arch_get_vdso_data(void)
 
 #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

@@ -68,7 +68,8 @@ long clock_getres_fallback(clockid_t clkid, struct __kernel_timespec *ts)
 }
 
 #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

@@ -58,7 +58,8 @@ extern struct ms_hyperv_tsc_page hvclock_page
 #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

@@ -49,13 +49,15 @@ static inline bool vdso_cycles_ok(u64 cycles)
 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
@@ -92,7 +94,8 @@ static __always_inline int do_hres_timens(const struct vdso_data *vdns, clockid_
 	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;
 }
@@ -162,7 +165,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 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;
@@ -310,7 +313,7 @@ __cvdso_gettimeofday_data(const struct vdso_data *vd,
 	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;
@@ -333,7 +336,7 @@ __cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
 
 	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);
 
@@ -363,7 +366,7 @@ int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
 
 	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