WSL2-Linux-Kernel/arch/x86
Thomas Gleixner 49116f2081 x86/vdso: Introduce and use vgtod_ts
It's desired to support more clocks in the VDSO, e.g. CLOCK_TAI. This
results either in indirect calls due to the larger switch case, which then
requires retpolines or when the compiler is forced to avoid jump tables it
results in even more conditionals.

To avoid both variants which are bad for performance the high resolution
functions and the coarse grained functions will be collapsed into one for
each. That requires to store the clock specific base time in an array.

Introcude struct vgtod_ts for storage and convert the data store, the
update function and the individual clock functions over to use it.

The new storage does not longer use gtod_long_t for seconds depending on 32
or 64 bit compile because this needs to be the full 64bit value even for
32bit when a Y2038 function is added. No point in keeping the distinction
alive in the internal representation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Matt Rickard <matt@softrans.com.au>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: devel@linuxdriverproject.org
Cc: virtualization@lists.linux-foundation.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Juergen Gross <jgross@suse.com>
Link: https://lkml.kernel.org/r/20180917130707.324679401@linutronix.de
2018-10-04 23:00:25 +02:00
..
boot
configs
crypto
entry x86/vdso: Introduce and use vgtod_ts 2018-10-04 23:00:25 +02:00
events
hyperv
ia32
include x86/vdso: Introduce and use vgtod_ts 2018-10-04 23:00:25 +02:00
kernel x86/vdso: Enforce 64bit clocksource 2018-10-04 23:00:25 +02:00
kvm
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Kconfig x86/time: Implement clocksource_arch_init() 2018-10-04 23:00:24 +02:00
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