| Message ID | 1461107270-19234-5-git-send-email-cota@braap.org |
|---|---|
| State | New |
| Headers | show |
Le 20/04/2016 01:07, Emilio G. Cota a écrit : > Taken from the linux kernel. > > Reviewed-by: Richard Henderson <rth@twiddle.net> > Signed-off-by: Emilio G. Cota <cota@braap.org> > --- > include/qemu/processor.h | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > create mode 100644 include/qemu/processor.h > > diff --git a/include/qemu/processor.h b/include/qemu/processor.h > new file mode 100644 > index 0000000..675a00a > --- /dev/null > +++ b/include/qemu/processor.h > @@ -0,0 +1,28 @@ Hi, Does this file need a license? Fred > +#ifndef QEMU_PROCESSOR_H > +#define QEMU_PROCESSOR_H > + > +#include "qemu/atomic.h" > + > +#if defined(__i386__) || defined(__x86_64__) > +#define cpu_relax() asm volatile("rep; nop" ::: "memory") > +#endif > + > +#ifdef __ia64__ > +#define cpu_relax() asm volatile("hint @pause" ::: "memory") > +#endif > + > +#ifdef __aarch64__ > +#define cpu_relax() asm volatile("yield" ::: "memory") > +#endif > + > +#if defined(__powerpc64__) > +/* set Hardware Multi-Threading (HMT) priority to low; then back to medium */ > +#define cpu_relax() asm volatile("or 1, 1, 1;" > + "or 2, 2, 2;" ::: "memory") > +#endif > + > +#ifndef cpu_relax > +#define cpu_relax() barrier() > +#endif > + > +#endif /* QEMU_PROCESSOR_H */ >
On Wed, Apr 20, 2016 at 14:15:41 +0200, KONRAD Frederic wrote: > Le 20/04/2016 01:07, Emilio G. Cota a écrit : > >Taken from the linux kernel. > > > >Reviewed-by: Richard Henderson <rth@twiddle.net> > >Signed-off-by: Emilio G. Cota <cota@braap.org> > >--- > > include/qemu/processor.h | 28 ++++++++++++++++++++++++++++ > > 1 file changed, 28 insertions(+) > > create mode 100644 include/qemu/processor.h > > > >diff --git a/include/qemu/processor.h b/include/qemu/processor.h > >new file mode 100644 > >index 0000000..675a00a > >--- /dev/null > >+++ b/include/qemu/processor.h > >@@ -0,0 +1,28 @@ > > Hi, > > Does this file need a license? I figured GPLv2 would apply to it by default. However, IANAL so I'd be happy to add a line to the patch stating the file is covered under GPLv2. Thanks, Emilio
On 20 April 2016 at 18:16, Emilio G. Cota <cota@braap.org> wrote: > On Wed, Apr 20, 2016 at 14:15:41 +0200, KONRAD Frederic wrote: >> Le 20/04/2016 01:07, Emilio G. Cota a écrit : >> >Taken from the linux kernel. >> > >> >Reviewed-by: Richard Henderson <rth@twiddle.net> >> >Signed-off-by: Emilio G. Cota <cota@braap.org> >> >--- >> > include/qemu/processor.h | 28 ++++++++++++++++++++++++++++ >> > 1 file changed, 28 insertions(+) >> > create mode 100644 include/qemu/processor.h >> > >> >diff --git a/include/qemu/processor.h b/include/qemu/processor.h >> >new file mode 100644 >> >index 0000000..675a00a >> >--- /dev/null >> >+++ b/include/qemu/processor.h >> >@@ -0,0 +1,28 @@ >> >> Hi, >> >> Does this file need a license? > > I figured GPLv2 would apply to it by default. However, IANAL so I'd > be happy to add a line to the patch stating the file is covered under > GPLv2. Yeah, in general we prefer new files to have at least a short copyright-and-license statement, though there are some older files (particularly headers) without. thanks -- PMM
Emilio G. Cota <cota@braap.org> writes: > Taken from the linux kernel. > > Reviewed-by: Richard Henderson <rth@twiddle.net> > Signed-off-by: Emilio G. Cota <cota@braap.org> License header notwithstanding: Reviewed-by: Alex Bennée <alex.bennee@linaro.org> > --- > include/qemu/processor.h | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > create mode 100644 include/qemu/processor.h > > diff --git a/include/qemu/processor.h b/include/qemu/processor.h > new file mode 100644 > index 0000000..675a00a > --- /dev/null > +++ b/include/qemu/processor.h > @@ -0,0 +1,28 @@ > +#ifndef QEMU_PROCESSOR_H > +#define QEMU_PROCESSOR_H > + > +#include "qemu/atomic.h" > + > +#if defined(__i386__) || defined(__x86_64__) > +#define cpu_relax() asm volatile("rep; nop" ::: "memory") > +#endif > + > +#ifdef __ia64__ > +#define cpu_relax() asm volatile("hint @pause" ::: "memory") > +#endif > + > +#ifdef __aarch64__ > +#define cpu_relax() asm volatile("yield" ::: "memory") > +#endif > + > +#if defined(__powerpc64__) > +/* set Hardware Multi-Threading (HMT) priority to low; then back to medium */ > +#define cpu_relax() asm volatile("or 1, 1, 1;" > + "or 2, 2, 2;" ::: "memory") > +#endif > + > +#ifndef cpu_relax > +#define cpu_relax() barrier() > +#endif > + > +#endif /* QEMU_PROCESSOR_H */ -- Alex Bennée
diff --git a/include/qemu/processor.h b/include/qemu/processor.h new file mode 100644 index 0000000..675a00a --- /dev/null +++ b/include/qemu/processor.h @@ -0,0 +1,28 @@ +#ifndef QEMU_PROCESSOR_H +#define QEMU_PROCESSOR_H + +#include "qemu/atomic.h" + +#if defined(__i386__) || defined(__x86_64__) +#define cpu_relax() asm volatile("rep; nop" ::: "memory") +#endif + +#ifdef __ia64__ +#define cpu_relax() asm volatile("hint @pause" ::: "memory") +#endif + +#ifdef __aarch64__ +#define cpu_relax() asm volatile("yield" ::: "memory") +#endif + +#if defined(__powerpc64__) +/* set Hardware Multi-Threading (HMT) priority to low; then back to medium */ +#define cpu_relax() asm volatile("or 1, 1, 1;" + "or 2, 2, 2;" ::: "memory") +#endif + +#ifndef cpu_relax +#define cpu_relax() barrier() +#endif + +#endif /* QEMU_PROCESSOR_H */