[PATCH v6 07/14] sparc64: vdso: Move hardware counter read into header

Thomas Weißschuh
2026-03-04T07:50:16Z

The generic vDSO libraries expected the architecture glue around hardware
counter reading in asm/vdso/gettimeofday.h. To prepare the adoption of the
generic library, move the existing functions there.

While at it, perform some trivial alignment with the generic vDSO library:
* Drop 'notrace', as the functions are __always_inline anyways
* Use the same parameter types
* Use the same function names

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Tested-by: Andreas Larsson <andreas@gaisler.com>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>
---
arch/sparc/include/asm/vdso/gettimeofday.h | 78 ++++++++++++++++++++++++++++++
arch/sparc/vdso/vclock_gettime.c | 70 ++-------------------------
2 files changed, 82 insertions(+), 66 deletions(-)

diff --git a/arch/sparc/include/asm/vdso/gettimeofday.h b/arch/sparc/include/asm/vdso/gettimeofday.h
new file mode 100644
index 000000000000..31f6505d3ab5
--- /dev/null
+++ b/arch/sparc/include/asm/vdso/gettimeofday.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ */
+
+#ifndef _ASM_SPARC_VDSO_GETTIMEOFDAY_H
+#define _ASM_SPARC_VDSO_GETTIMEOFDAY_H
+
+#include <linux/types.h>
+#include <asm/vvar.h>
+
+#ifdef CONFIG_SPARC64
+static __always_inline u64 vdso_shift_ns(u64 val, u32 amt)
+{
+ return val >> amt;
+}
+
+static __always_inline u64 vread_tick(void)
+{
+ u64 ret;
+
+ __asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
+ return ret;
+}
+
+static __always_inline u64 vread_tick_stick(void)
+{
+ u64 ret;
+
+ __asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
+ return ret;
+}
+#else
+static __always_inline u64 vdso_shift_ns(u64 val, u32 amt)
+{
+ u64 ret;
+
+ __asm__ __volatile__("sllx %H1, 32, %%g1\n\t"
+ "srl %L1, 0, %L1\n\t"
+ "or %%g1, %L1, %%g1\n\t"
+ "srlx %%g1, %2, %L0\n\t"
+ "srlx %L0, 32, %H0"
+ : "=r" (ret)
+ : "r" (val), "r" (amt)
+ : "g1");
+ return ret;
+}
+
+static __always_inline u64 vread_tick(void)
+{
+ register unsigned long long ret asm("o4");
+
+ __asm__ __volatile__("rd %%tick, %L0\n\t"
+ "srlx %L0, 32, %H0"
+ : "=r" (ret));
+ return ret;
+}
+
+static __always_inline u64 vread_tick_stick(void)
+{
+ register unsigned long long ret asm("o4");
+
+ __asm__ __volatile__("rd %%asr24, %L0\n\t"
+ "srlx %L0, 32, %H0"
+ : "=r" (ret));
+ return ret;
+}
+#endif
+
+static __always_inline u64 __arch_get_hw_counter(struct vvar_data *vvar)
+{
+ if (likely(vvar->vclock_mode == VCLOCK_STICK))
+ return vread_tick_stick();
+ else
+ return vread_tick();
+}
+
+#endif /* _ASM_SPARC_VDSO_GETTIMEOFDAY_H */
diff --git a/arch/sparc/vdso/vclock_gettime.c b/arch/sparc/vdso/vclock_gettime.c
index 643608bffe13..16ac80982a00 100644
--- a/arch/sparc/vdso/vclock_gettime.c
+++ b/arch/sparc/vdso/vclock_gettime.c
@@ -19,6 +19,7 @@
#include <asm/unistd.h>
#include <asm/timex.h>
#include <asm/clocksource.h>
+#include <asm/vdso/gettimeofday.h>
#include <asm/vvar.h>

#ifdef CONFIG_SPARC64
@@ -85,73 +86,10 @@ notrace static long vdso_fallback_gettimeofday(struct __kernel_old_timeval *tv,
return o0;
}

-#ifdef CONFIG_SPARC64
-notrace static __always_inline u64 __shr64(u64 val, int amt)
-{
- return val >> amt;
-}
-
-notrace static __always_inline u64 vread_tick(void)
-{
- u64 ret;
-
- __asm__ __volatile__("rd %%tick, %0" : "=r" (ret));
- return ret;
-}
-
-notrace static __always_inline u64 vread_tick_stick(void)
-{
- u64 ret;
-
- __asm__ __volatile__("rd %%asr24, %0" : "=r" (ret));
- return ret;
-}
-#else
-notrace static __always_inline u64 __shr64(u64 val, int amt)
-{
- u64 ret;
-
- __asm__ __volatile__("sllx %H1, 32, %%g1\n\t"
- "srl %L1, 0, %L1\n\t"
- "or %%g1, %L1, %%g1\n\t"
- "srlx %%g1, %2, %L0\n\t"
- "srlx %L0, 32, %H0"
- : "=r" (ret)
- : "r" (val), "r" (amt)
- : "g1");
- return ret;
-}
-
-notrace static __always_inline u64 vread_tick(void)
-{
- register unsigned long long ret asm("o4");
-
- __asm__ __volatile__("rd %%tick, %L0\n\t"
- "srlx %L0, 32, %H0"
- : "=r" (ret));
- return ret;
-}
-
-notrace static __always_inline u64 vread_tick_stick(void)
-{
- register unsigned long long ret asm("o4");
-
- __asm__ __volatile__("rd %%asr24, %L0\n\t"
- "srlx %L0, 32, %H0"
- : "=r" (ret));
- return ret;
-}
-#endif
-
notrace static __always_inline u64 vgetsns(struct vvar_data *vvar)
{
u64 v;
- u64 cycles;
-
- if (likely(vvar->vclock_mode == VCLOCK_STICK))
- cycles = vread_tick_stick();
- else
- cycles = vread_tick();
+ u64 cycles = __arch_get_hw_counter(vvar);

v = (cycles - vvar->clock.cycle_last) & vvar->clock.mask;
return v * vvar->clock.mult;
@@ -168,7 +106,7 @@ notrace static __always_inline int do_realtime(struct vvar_data *vvar,
ts->tv_sec = vvar->wall_time_sec;
ns = vvar->wall_time_snsec;
ns += vgetsns(vvar);
- ns = __shr64(ns, vvar->clock.shift);
+ ns = vdso_shift_ns(ns, vvar->clock.shift);
} while (unlikely(vvar_read_retry(vvar, seq)));

ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
@@ -188,7 +126,7 @@ notrace static __always_inline int do_monotonic(struct vvar_data *vvar,
ts->tv_sec = vvar->monotonic_time_sec;
ns = vvar->monotonic_time_snsec;
ns += vgetsns(vvar);
- ns = __shr64(ns, vvar->clock.shift);
+ ns = vdso_shift_ns(ns, vvar->clock.shift);
} while (unlikely(vvar_read_retry(vvar, seq)));

ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);

--
2.53.0