lib/vdso: Allow fixed clock mode (ae12e085) · Commits · 戴 / test

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

lib/vdso/gettimeofday.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -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);

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