| Message ID | 20210125140136.10494-21-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/41] drm/i915/selftests: Check for engine-reset errors in the middle of workarounds | expand |
On 25/01/2021 14:01, Chris Wilson wrote: > Wrap cmpxchg64 with a try_cmpxchg()-esque helper. Hiding the old-value > dance in the helper allows for cleaner code. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > --- > drivers/gpu/drm/i915/i915_utils.h | 32 +++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h > index abd4dcd9f79c..95ead6bb1ba6 100644 > --- a/drivers/gpu/drm/i915/i915_utils.h > +++ b/drivers/gpu/drm/i915/i915_utils.h > @@ -461,4 +461,36 @@ static inline bool timer_expired(const struct timer_list *t) > */ > #define IS_ACTIVE(config) ((config) != 0) > > +#ifndef try_cmpxchg64 > +#if IS_ENABLED(CONFIG_64BIT) > +#define try_cmpxchg64(_ptr, _pold, _new) try_cmpxchg(_ptr, _pold, _new) > +#else > +#define try_cmpxchg64(_ptr, _pold, _new) \ > +({ \ > + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ > + __typeof__(*(_ptr)) __old = *_old; \ > + __typeof__(*(_ptr)) __cur = cmpxchg64(_ptr, __old, _new); \ > + bool success = __cur == __old; \ > + if (unlikely(!success)) \ > + *_old = __cur; \ > + likely(success); \ > +}) > +#endif > +#endif > + > +#ifndef xchg64 > +#if IS_ENABLED(CONFIG_64BIT) > +#define xchg64(_ptr, _new) xchg(_ptr, _new) > +#else > +#define xchg64(_ptr, _new) \ > +({ \ > + __typeof__(_ptr) __ptr = (_ptr); \ > + __typeof__(*(_ptr)) __old = *__ptr; \ > + while (!try_cmpxchg64(__ptr, &__old, (_new))) \ > + ; \ > + __old; \ > +}) > +#endif > +#endif > + > #endif /* !__I915_UTILS_H */ > Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h index abd4dcd9f79c..95ead6bb1ba6 100644 --- a/drivers/gpu/drm/i915/i915_utils.h +++ b/drivers/gpu/drm/i915/i915_utils.h @@ -461,4 +461,36 @@ static inline bool timer_expired(const struct timer_list *t) */ #define IS_ACTIVE(config) ((config) != 0) +#ifndef try_cmpxchg64 +#if IS_ENABLED(CONFIG_64BIT) +#define try_cmpxchg64(_ptr, _pold, _new) try_cmpxchg(_ptr, _pold, _new) +#else +#define try_cmpxchg64(_ptr, _pold, _new) \ +({ \ + __typeof__(_ptr) _old = (__typeof__(_ptr))(_pold); \ + __typeof__(*(_ptr)) __old = *_old; \ + __typeof__(*(_ptr)) __cur = cmpxchg64(_ptr, __old, _new); \ + bool success = __cur == __old; \ + if (unlikely(!success)) \ + *_old = __cur; \ + likely(success); \ +}) +#endif +#endif + +#ifndef xchg64 +#if IS_ENABLED(CONFIG_64BIT) +#define xchg64(_ptr, _new) xchg(_ptr, _new) +#else +#define xchg64(_ptr, _new) \ +({ \ + __typeof__(_ptr) __ptr = (_ptr); \ + __typeof__(*(_ptr)) __old = *__ptr; \ + while (!try_cmpxchg64(__ptr, &__old, (_new))) \ + ; \ + __old; \ +}) +#endif +#endif + #endif /* !__I915_UTILS_H */
Wrap cmpxchg64 with a try_cmpxchg()-esque helper. Hiding the old-value dance in the helper allows for cleaner code. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> --- drivers/gpu/drm/i915/i915_utils.h | 32 +++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)