| Message ID | 1440535491-4511-5-git-send-email-lvivier@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Aug 25, 2015 at 1:44 PM, Laurent Vivier <lvivier@redhat.com> wrote: > muldiv64() is used to convert microseconds to nanoseconds. > > Use qemu_clock_get_ns() instead of qemu_clock_get_us() > to avoid this operation. > > Signed-off-by: Laurent Vivier <lvivier@redhat.com> > --- > target-arm/helper.c | 9 +++------ > 1 file changed, 3 insertions(+), 6 deletions(-) > > diff --git a/target-arm/helper.c b/target-arm/helper.c > index 1568aa6..f5e8fd8 100644 > --- a/target-arm/helper.c > +++ b/target-arm/helper.c > @@ -678,8 +678,7 @@ void pmccntr_sync(CPUARMState *env) > { > uint64_t temp_ticks; > > - temp_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), > - get_ticks_per_sec(), 1000000); > + temp_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > > if (env->cp15.c9_pmcr & PMCRD) { > /* Increment once every 64 processor clock cycles */ > @@ -717,8 +716,7 @@ static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri) > return env->cp15.c15_ccnt; > } > > - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), > - get_ticks_per_sec(), 1000000); > + total_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > The long term goal here was to replace get_ticks_per_sec with a parameterizable CPU frequency so ideally the math should remain. The ARM CPU frequency == get_ticks_per_sec is the bigger issue. Regards, Peter > if (env->cp15.c9_pmcr & PMCRD) { > /* Increment once every 64 processor clock cycles */ > @@ -738,8 +736,7 @@ static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri, > return; > } > > - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), > - get_ticks_per_sec(), 1000000); > + total_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > > if (env->cp15.c9_pmcr & PMCRD) { > /* Increment once every 64 processor clock cycles */ > -- > 2.1.0 > >
On 25/08/2015 23:11, Peter Crosthwaite wrote: > On Tue, Aug 25, 2015 at 1:44 PM, Laurent Vivier <lvivier@redhat.com> wrote: >> muldiv64() is used to convert microseconds to nanoseconds. >> >> Use qemu_clock_get_ns() instead of qemu_clock_get_us() >> to avoid this operation. >> >> Signed-off-by: Laurent Vivier <lvivier@redhat.com> >> --- >> target-arm/helper.c | 9 +++------ >> 1 file changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/target-arm/helper.c b/target-arm/helper.c >> index 1568aa6..f5e8fd8 100644 >> --- a/target-arm/helper.c >> +++ b/target-arm/helper.c >> @@ -678,8 +678,7 @@ void pmccntr_sync(CPUARMState *env) >> { >> uint64_t temp_ticks; >> >> - temp_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), >> - get_ticks_per_sec(), 1000000); >> + temp_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); >> >> if (env->cp15.c9_pmcr & PMCRD) { >> /* Increment once every 64 processor clock cycles */ >> @@ -717,8 +716,7 @@ static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri) >> return env->cp15.c15_ccnt; >> } >> >> - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), >> - get_ticks_per_sec(), 1000000); >> + total_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); >> > > The long term goal here was to replace get_ticks_per_sec with a > parameterizable CPU frequency so ideally the math should remain. The > ARM CPU frequency == get_ticks_per_sec is the bigger issue. OK, I will remove this one from the series. Perhaps a comment in the original functions would help to understand what we are doing here... or something like that: #define ARM_CPU_FREQ 1000000000 /* FIXME: should be parameterizable */ #define NSEC_PER_SEC 1000000000 total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), ARM_CPU_FREQ, NSEC_PER_SEC); Laurent > Regards, > Peter > >> if (env->cp15.c9_pmcr & PMCRD) { >> /* Increment once every 64 processor clock cycles */ >> @@ -738,8 +736,7 @@ static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri, >> return; >> } >> >> - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), >> - get_ticks_per_sec(), 1000000); >> + total_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); >> >> if (env->cp15.c9_pmcr & PMCRD) { >> /* Increment once every 64 processor clock cycles */ >> -- >> 2.1.0 >> >>
diff --git a/target-arm/helper.c b/target-arm/helper.c index 1568aa6..f5e8fd8 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -678,8 +678,7 @@ void pmccntr_sync(CPUARMState *env) { uint64_t temp_ticks; - temp_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + temp_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ @@ -717,8 +716,7 @@ static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri) return env->cp15.c15_ccnt; } - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + total_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */ @@ -738,8 +736,7 @@ static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri, return; } - total_ticks = muldiv64(qemu_clock_get_us(QEMU_CLOCK_VIRTUAL), - get_ticks_per_sec(), 1000000); + total_ticks = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); if (env->cp15.c9_pmcr & PMCRD) { /* Increment once every 64 processor clock cycles */
muldiv64() is used to convert microseconds to nanoseconds. Use qemu_clock_get_ns() instead of qemu_clock_get_us() to avoid this operation. Signed-off-by: Laurent Vivier <lvivier@redhat.com> --- target-arm/helper.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)