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authorChristophe Leroy <christophe.leroy@c-s.fr>2020-02-07 13:39:02 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-02-17 20:12:18 +0100
commitae12e08539de6717502c2f9f83bd60df939b5c08 (patch)
tree9b62f854c65da4af87519992fca91f3e9ae75582 /lib/vdso
parent2d6b01bd88ccabba06d342ef80eaab6b39d12497 (diff)
downloadlinux-ae12e08539de6717502c2f9f83bd60df939b5c08.tar.bz2
lib/vdso: Allow fixed clock mode
Some architectures have a fixed clocksource which is known at compile time and cannot be replaced or disabled at runtime, e.g. timebase on PowerPC. For such cases the clock mode check in the VDSO code is pointless. Move the check for a VDSO capable clocksource into an inline function and allow architectures to redefine it via a macro. [ tglx: Removed the #ifdef mess ] Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124403.748756829@linutronix.de
Diffstat (limited to 'lib/vdso')
-rw-r--r--lib/vdso/gettimeofday.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index a76ac8d17c5f..8eb6d1e9a8ff 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -46,6 +46,13 @@ static inline bool __arch_vdso_hres_capable(void)
}
#endif
+#ifndef vdso_clocksource_ok
+static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+{
+ return vd->clock_mode != VDSO_CLOCKMODE_NONE;
+}
+#endif
+
#ifdef CONFIG_TIME_NS
static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
struct __kernel_timespec *ts)
@@ -66,7 +73,7 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
do {
seq = vdso_read_begin(vd);
- if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+ if (unlikely(!vdso_clocksource_ok(vd)))
return -1;
cycles = __arch_get_hw_counter(vd->clock_mode);
@@ -134,7 +141,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
}
smp_rmb();
- if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+ if (unlikely(!vdso_clocksource_ok(vd)))
return -1;
cycles = __arch_get_hw_counter(vd->clock_mode);