| Message ID | 20211006123609.2026-1-christian.koenig@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] dma-buf: add dma_resv_for_each_fence v3 | expand |
On 06/10/2021 13:36, Christian König wrote: > A simpler version of the iterator to be used when the dma_resv object is > locked. > > v2: fix index check here as well > v3: minor coding improvement, some documentation cleanup > > Signed-off-by: Christian König <christian.koenig@amd.com> > --- > drivers/dma-buf/dma-resv.c | 51 ++++++++++++++++++++++++++++++++++++++ > include/linux/dma-resv.h | 20 +++++++++++++++ > 2 files changed, 71 insertions(+) > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c > index a480af9581bd..2f98caa68ae5 100644 > --- a/drivers/dma-buf/dma-resv.c > +++ b/drivers/dma-buf/dma-resv.c > @@ -423,6 +423,57 @@ struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor) > } > EXPORT_SYMBOL(dma_resv_iter_next_unlocked); > > +/** > + * dma_resv_iter_first - first fence from a locked dma_resv object > + * @cursor: cursor to record the current position > + * > + * Return the first fence in the dma_resv object while holding the > + * &dma_resv.lock. > + */ > +struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor) > +{ > + struct dma_fence *fence; > + > + dma_resv_assert_held(cursor->obj); > + > + cursor->index = 0; > + if (cursor->all_fences) > + cursor->fences = dma_resv_shared_list(cursor->obj); > + else > + cursor->fences = NULL; > + > + fence = dma_resv_excl_fence(cursor->obj); > + if (!fence) > + fence = dma_resv_iter_next(cursor); > + > + cursor->is_restarted = true; > + return fence; > +} > +EXPORT_SYMBOL_GPL(dma_resv_iter_first); > + > +/** > + * dma_resv_iter_next - next fence from a locked dma_resv object > + * @cursor: cursor to record the current position > + * > + * Return the next fences from the dma_resv object while holding the > + * &dma_resv.lock. > + */ > +struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor) > +{ > + unsigned int idx; > + > + dma_resv_assert_held(cursor->obj); > + > + cursor->is_restarted = false; > + if (!cursor->fences || cursor->index >= cursor->fences->shared_count) > + return NULL; > + > + idx = cursor->index++; > + return rcu_dereference_protected(cursor->fences->shared[idx], > + dma_resv_held(cursor->obj)); > +} > +EXPORT_SYMBOL_GPL(dma_resv_iter_next); > + > /** > * dma_resv_copy_fences - Copy all fences from src to dst. > * @dst: the destination reservation object > diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h > index 764138ad8583..491359cea54c 100644 > --- a/include/linux/dma-resv.h > +++ b/include/linux/dma-resv.h > @@ -179,6 +179,8 @@ struct dma_resv_iter { > > struct dma_fence *dma_resv_iter_first_unlocked(struct dma_resv_iter *cursor); > struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor); > +struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor); > +struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor); > > /** > * dma_resv_iter_begin - initialize a dma_resv_iter object > @@ -244,6 +246,24 @@ static inline bool dma_resv_iter_is_restarted(struct dma_resv_iter *cursor) > for (fence = dma_resv_iter_first_unlocked(cursor); \ > fence; fence = dma_resv_iter_next_unlocked(cursor)) > > +/** > + * dma_resv_for_each_fence - fence iterator > + * @cursor: a struct dma_resv_iter pointer > + * @obj: a dma_resv object pointer > + * @all_fences: true if all fences should be returned > + * @fence: the current fence > + * > + * Iterate over the fences in a struct dma_resv object while holding the > + * &dma_resv.lock. @all_fences controls if the shared fences are returned as > + * well. The cursor initialisation is part of the iterator and the fence stays > + * valid as long as the lock is held and so no extra reference to the fence is > + * taken. > + */ > +#define dma_resv_for_each_fence(cursor, obj, all_fences, fence) \ > + for (dma_resv_iter_begin(cursor, obj, all_fences), \ > + fence = dma_resv_iter_first(cursor); fence; \ > + fence = dma_resv_iter_next(cursor)) > + > #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base) > #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base) > > Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Regards, Tvrtko
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index a480af9581bd..2f98caa68ae5 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -423,6 +423,57 @@ struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor) } EXPORT_SYMBOL(dma_resv_iter_next_unlocked); +/** + * dma_resv_iter_first - first fence from a locked dma_resv object + * @cursor: cursor to record the current position + * + * Return the first fence in the dma_resv object while holding the + * &dma_resv.lock. + */ +struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor) +{ + struct dma_fence *fence; + + dma_resv_assert_held(cursor->obj); + + cursor->index = 0; + if (cursor->all_fences) + cursor->fences = dma_resv_shared_list(cursor->obj); + else + cursor->fences = NULL; + + fence = dma_resv_excl_fence(cursor->obj); + if (!fence) + fence = dma_resv_iter_next(cursor); + + cursor->is_restarted = true; + return fence; +} +EXPORT_SYMBOL_GPL(dma_resv_iter_first); + +/** + * dma_resv_iter_next - next fence from a locked dma_resv object + * @cursor: cursor to record the current position + * + * Return the next fences from the dma_resv object while holding the + * &dma_resv.lock. + */ +struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor) +{ + unsigned int idx; + + dma_resv_assert_held(cursor->obj); + + cursor->is_restarted = false; + if (!cursor->fences || cursor->index >= cursor->fences->shared_count) + return NULL; + + idx = cursor->index++; + return rcu_dereference_protected(cursor->fences->shared[idx], + dma_resv_held(cursor->obj)); +} +EXPORT_SYMBOL_GPL(dma_resv_iter_next); + /** * dma_resv_copy_fences - Copy all fences from src to dst. * @dst: the destination reservation object diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h index 764138ad8583..491359cea54c 100644 --- a/include/linux/dma-resv.h +++ b/include/linux/dma-resv.h @@ -179,6 +179,8 @@ struct dma_resv_iter { struct dma_fence *dma_resv_iter_first_unlocked(struct dma_resv_iter *cursor); struct dma_fence *dma_resv_iter_next_unlocked(struct dma_resv_iter *cursor); +struct dma_fence *dma_resv_iter_first(struct dma_resv_iter *cursor); +struct dma_fence *dma_resv_iter_next(struct dma_resv_iter *cursor); /** * dma_resv_iter_begin - initialize a dma_resv_iter object @@ -244,6 +246,24 @@ static inline bool dma_resv_iter_is_restarted(struct dma_resv_iter *cursor) for (fence = dma_resv_iter_first_unlocked(cursor); \ fence; fence = dma_resv_iter_next_unlocked(cursor)) +/** + * dma_resv_for_each_fence - fence iterator + * @cursor: a struct dma_resv_iter pointer + * @obj: a dma_resv object pointer + * @all_fences: true if all fences should be returned + * @fence: the current fence + * + * Iterate over the fences in a struct dma_resv object while holding the + * &dma_resv.lock. @all_fences controls if the shared fences are returned as + * well. The cursor initialisation is part of the iterator and the fence stays + * valid as long as the lock is held and so no extra reference to the fence is + * taken. + */ +#define dma_resv_for_each_fence(cursor, obj, all_fences, fence) \ + for (dma_resv_iter_begin(cursor, obj, all_fences), \ + fence = dma_resv_iter_first(cursor); fence; \ + fence = dma_resv_iter_next(cursor)) + #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base) #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
A simpler version of the iterator to be used when the dma_resv object is locked. v2: fix index check here as well v3: minor coding improvement, some documentation cleanup Signed-off-by: Christian König <christian.koenig@amd.com> --- drivers/dma-buf/dma-resv.c | 51 ++++++++++++++++++++++++++++++++++++++ include/linux/dma-resv.h | 20 +++++++++++++++ 2 files changed, 71 insertions(+)