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