Le 08/03/2024 à 14:14, Adrian Hunter a écrit : > [Vous ne recevez pas souvent de courriers de adrian.hunter@xxxxxxxxx. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ] > > Consolidate vdso_calc_delta(), in preparation for further simplification. > > Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> > --- > arch/powerpc/include/asm/vdso/gettimeofday.h | 17 ++--------------- > arch/s390/include/asm/vdso/gettimeofday.h | 7 ++----- > lib/vdso/gettimeofday.c | 4 ++++ > 3 files changed, 8 insertions(+), 20 deletions(-) > > diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h b/arch/powerpc/include/asm/vdso/gettimeofday.h > index f0a4cf01e85c..f4da8e18cdf3 100644 > --- a/arch/powerpc/include/asm/vdso/gettimeofday.h > +++ b/arch/powerpc/include/asm/vdso/gettimeofday.h > @@ -14,6 +14,8 @@ > > #define VDSO_HAS_TIME 1 > > +#define VDSO_DELTA_NOMASK 1 > + > static __always_inline int do_syscall_2(const unsigned long _r0, const unsigned long _r3, > const unsigned long _r4) > { > @@ -105,21 +107,6 @@ 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. > - */ Please keep the comment. You can move it close to VDSO_DELTA_NOMASK > -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) > { > diff --git a/arch/s390/include/asm/vdso/gettimeofday.h b/arch/s390/include/asm/vdso/gettimeofday.h > index db84942eb78f..7937765ccfa5 100644 > --- a/arch/s390/include/asm/vdso/gettimeofday.h > +++ b/arch/s390/include/asm/vdso/gettimeofday.h > @@ -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) > { > diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c > index ce2f69552003..042b95e8164d 100644 > --- a/lib/vdso/gettimeofday.c > +++ b/lib/vdso/gettimeofday.c > @@ -13,7 +13,11 @@ > static __always_inline > u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult) > { > +#ifdef VDSO_DELTA_NOMASK > + return (cycles - last) * mult; > +#else > return ((cycles - last) & mask) * mult; > +#endif See https://docs.kernel.org/process/coding-style.html#conditional-compilation You don't need #ifdefs here. One solution is to define VDSO_DELTA_NOMASK to 0 in include/vdso/datapage.h after including asm/vdso/gettimeofday.h : #ifndef VDSO_DELTA_NOMASK #define VDSO_DELTA_NOMASK 0 #endif Then u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult) { if (VDSO_DELTA_NOMASK) mask = ~0ULL; return ((cycles - last) & mask) * mult; } or u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult) { if (VDSO_DELTA_NOMASK) return (cycles - last) * mult; return ((cycles - last) & mask) * mult; } > } > #endif > > -- > 2.34.1 >
