[PATCH 1/4] dma-buf: add dma_fence_array_for_each (v2)

[Jason Ekstrand]

On Fri, May 21, 2021 at 2:51 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 20.05.21 um 21:00 schrieb Jason Ekstrand:
> > From: Christian König <ckoenig.leichtzumerken at gmail.com>
> >
> > Add a helper to iterate over all fences in a dma_fence_array object.
> >
> > v2 (Jason Ekstrand)
> >   - Return NULL from dma_fence_array_first if head == NULL.  This matches
> >     the iterator behavior of dma_fence_chain_for_each in that it iterates
> >     zero times if head == NULL.
> >   - Return NULL from dma_fence_array_next if index > array->num_fences.
> >
> > Signed-off-by: Jason Ekstrand <jason at jlekstrand.net>
>
> Reviewed-by: Christian König <christian.koenig at amd.com>
>
> BTW: I'm only seeing this patch from the series. Looks like somehow the
> rest didn't made it into my inbox.

https://lists.freedesktop.org/archives/dri-devel/2021-May/307561.html

Not sure why it didn't make your mail.  This one was CC'd to you
because you're the author from a year ago or something.

--Jason


> > ---
> >   drivers/dma-buf/dma-fence-array.c | 27 +++++++++++++++++++++++++++
> >   include/linux/dma-fence-array.h   | 17 +++++++++++++++++
> >   2 files changed, 44 insertions(+)
> >
> > diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
> > index d3fbd950be944..2ac1afc697d0f 100644
> > --- a/drivers/dma-buf/dma-fence-array.c
> > +++ b/drivers/dma-buf/dma-fence-array.c
> > @@ -201,3 +201,30 @@ bool dma_fence_match_context(struct dma_fence *fence, u64 context)
> >       return true;
> >   }
> >   EXPORT_SYMBOL(dma_fence_match_context);
> > +
> > +struct dma_fence *dma_fence_array_first(struct dma_fence *head)
> > +{
> > +     struct dma_fence_array *array;
> > +
> > +     if (!head)
> > +             return NULL;
> > +
> > +     array = to_dma_fence_array(head);
> > +     if (!array)
> > +             return head;
> > +
> > +     return array->fences[0];
> > +}
> > +EXPORT_SYMBOL(dma_fence_array_first);
> > +
> > +struct dma_fence *dma_fence_array_next(struct dma_fence *head,
> > +                                    unsigned int index)
> > +{
> > +     struct dma_fence_array *array = to_dma_fence_array(head);
> > +
> > +     if (!array || index >= array->num_fences)
> > +             return NULL;
> > +
> > +     return array->fences[index];
> > +}
> > +EXPORT_SYMBOL(dma_fence_array_next);
> > diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h
> > index 303dd712220fd..588ac8089dd61 100644
> > --- a/include/linux/dma-fence-array.h
> > +++ b/include/linux/dma-fence-array.h
> > @@ -74,6 +74,19 @@ to_dma_fence_array(struct dma_fence *fence)
> >       return container_of(fence, struct dma_fence_array, base);
> >   }
> >
> > +/**
> > + * dma_fence_array_for_each - iterate over all fences in array
> > + * @fence: current fence
> > + * @index: index into the array
> > + * @head: potential dma_fence_array object
> > + *
> > + * Test if @array is a dma_fence_array object and if yes iterate over all fences
> > + * in the array. If not just iterate over the fence in @array itself.
> > + */
> > +#define dma_fence_array_for_each(fence, index, head)                 \
> > +     for (index = 0, fence = dma_fence_array_first(head); fence;     \
> > +          ++(index), fence = dma_fence_array_next(head, index))
> > +
> >   struct dma_fence_array *dma_fence_array_create(int num_fences,
> >                                              struct dma_fence **fences,
> >                                              u64 context, unsigned seqno,
> > @@ -81,4 +94,8 @@ struct dma_fence_array *dma_fence_array_create(int num_fences,
> >
> >   bool dma_fence_match_context(struct dma_fence *fence, u64 context);
> >
> > +struct dma_fence *dma_fence_array_first(struct dma_fence *head);
> > +struct dma_fence *dma_fence_array_next(struct dma_fence *head,
> > +                                    unsigned int index);
> > +
> >   #endif /* __LINUX_DMA_FENCE_ARRAY_H */
>