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vdso: Consolidate vdso_calc_delta() 

Consolidate vdso_calc_delta(), in preparation for further simplification.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240325064023.2997-2-adrian.hunter@intel.com
This commit is contained in:
Adrian Hunter 2024-03-25 08:40:05 +02:00 committed by Thomas Gleixner
parent 82ccdf062a
commit c8e3a8b6f2
3 changed files with 21 additions and 21 deletions
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26
arch/powerpc/include/asm/vdso/gettimeofday.h
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@ -13,6 +13,17 @@
#define VDSO_HAS_TIME 1
/*
* powerpc specific delta calculation.
*
* This variant removes the masking of the subtraction because the
* clocksource mask of all VDSO capable clocksources on powerpc is U64_MAX
* which would result in a pointless operation. The compiler cannot
* optimize it away as the mask comes from the vdso data and is not compile
* time constant.
*/
#define VDSO_DELTA_NOMASK 1
static __always_inline int do_syscall_2(const unsigned long _r0, const unsigned long _r3,
const unsigned long _r4)
{
@ -104,21 +115,6 @@ static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
}
#define vdso_clocksource_ok vdso_clocksource_ok
/*
* powerpc specific delta calculation.
*
* This variant removes the masking of the subtraction because the
* clocksource mask of all VDSO capable clocksources on powerpc is U64_MAX
* which would result in a pointless operation. The compiler cannot
* optimize it away as the mask comes from the vdso data and is not compile
* time constant.
*/
static __always_inline u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
{
return (cycles - last) * mult;
}
#define vdso_calc_delta vdso_calc_delta
#ifndef __powerpc64__
static __always_inline u64 vdso_shift_ns(u64 ns, unsigned long shift)
{

7
arch/s390/include/asm/vdso/gettimeofday.h
View File

@ -6,16 +6,13 @@
#define VDSO_HAS_CLOCK_GETRES 1
#define VDSO_DELTA_NOMASK 1
#include <asm/syscall.h>
#include <asm/timex.h>
#include <asm/unistd.h>
#include <linux/compiler.h>
#define vdso_calc_delta __arch_vdso_calc_delta
static __always_inline u64 __arch_vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
{
return (cycles - last) * mult;
}
static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
{

9
lib/vdso/gettimeofday.c
View File

@ -6,6 +6,13 @@
#include <vdso/helpers.h>
#ifndef vdso_calc_delta
#ifdef VDSO_DELTA_NOMASK
# define VDSO_DELTA_MASK(mask) U64_MAX
#else
# define VDSO_DELTA_MASK(mask) (mask)
#endif
/*
* Default implementation which works for all sane clocksources. That
* obviously excludes x86/TSC.
@ -13,7 +20,7 @@
static __always_inline
u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
{
return ((cycles - last) & mask) * mult;
return ((cycles - last) & VDSO_DELTA_MASK(mask)) * mult;
}
#endif