*/
#include <linux/dma-resv.h>
+#include <linux/dma-fence-array.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
EXPORT_SYMBOL_GPL(dma_resv_get_fences);
/**
+ * dma_resv_get_singleton - Get a single fence for all the fences
+ * @obj: the reservation object
+ * @write: true if we should return all fences
+ * @fence: the resulting fence
+ *
+ * Get a single fence representing all the fences inside the resv object.
+ * Returns either 0 for success or -ENOMEM.
+ *
+ * Warning: This can't be used like this when adding the fence back to the resv
+ * object since that can lead to stack corruption when finalizing the
+ * dma_fence_array.
+ *
+ * Returns 0 on success and negative error values on failure.
+ */
+int dma_resv_get_singleton(struct dma_resv *obj, bool write,
+ struct dma_fence **fence)
+{
+ struct dma_fence_array *array;
+ struct dma_fence **fences;
+ unsigned count;
+ int r;
+
+ r = dma_resv_get_fences(obj, write, &count, &fences);
+ if (r)
+ return r;
+
+ if (count == 0) {
+ *fence = NULL;
+ return 0;
+ }
+
+ if (count == 1) {
+ *fence = fences[0];
+ kfree(fences);
+ return 0;
+ }
+
+ array = dma_fence_array_create(count, fences,
+ dma_fence_context_alloc(1),
+ 1, false);
+ if (!array) {
+ while (count--)
+ dma_fence_put(fences[count]);
+ kfree(fences);
+ return -ENOMEM;
+ }
+
+ *fence = &array->base;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dma_resv_get_singleton);
+
+/**
* dma_resv_wait_timeout - Wait on reservation's objects
* shared and/or exclusive fences.
* @obj: the reservation object
void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence);
int dma_resv_get_fences(struct dma_resv *obj, bool write,
unsigned int *num_fences, struct dma_fence ***fences);
+int dma_resv_get_singleton(struct dma_resv *obj, bool write,
+ struct dma_fence **fence);
int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src);
long dma_resv_wait_timeout(struct dma_resv *obj, bool wait_all, bool intr,
unsigned long timeout);