dma-buf: Split out dma fence array create into alloc and arm functions

Useful to preallocate dma fence array and then arm in path of reclaim or
a dma fence.

v2:
 - s/arm/init (Christian)
 - Drop !array warn (Christian)
v3:
 - Fix kernel doc typos (dim)

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240826170144.2492062-2-matthew.brost@intel.com

diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c
index c74ac197d5fea1dd3a83e3350e3dac05bd9f00a2..8a08ffde31e7580b48db1a4e685c5bdb456b34a4 100644 (file)
--- a/drivers/dma-buf/dma-fence-array.c
+++ b/drivers/dma-buf/dma-fence-array.c
@@ -144,37 +144,38 @@ const struct dma_fence_ops dma_fence_array_ops = {
 EXPORT_SYMBOL(dma_fence_array_ops);
 
 /**
- * dma_fence_array_create - Create a custom fence array
+ * dma_fence_array_alloc - Allocate a custom fence array
+ * @num_fences:                [in]    number of fences to add in the array
+ *
+ * Return dma fence array on success, NULL on failure
+ */
+struct dma_fence_array *dma_fence_array_alloc(int num_fences)
+{
+       struct dma_fence_array *array;
+
+       return kzalloc(struct_size(array, callbacks, num_fences), GFP_KERNEL);
+}
+EXPORT_SYMBOL(dma_fence_array_alloc);
+
+/**
+ * dma_fence_array_init - Init a custom fence array
+ * @array:             [in]    dma fence array to arm
  * @num_fences:                [in]    number of fences to add in the array
  * @fences:            [in]    array containing the fences
  * @context:           [in]    fence context to use
  * @seqno:             [in]    sequence number to use
  * @signal_on_any:     [in]    signal on any fence in the array
  *
- * Allocate a dma_fence_array object and initialize the base fence with
- * dma_fence_init().
- * In case of error it returns NULL.
- *
- * The caller should allocate the fences array with num_fences size
- * and fill it with the fences it wants to add to the object. Ownership of this
- * array is taken and dma_fence_put() is used on each fence on release.
- *
- * If @signal_on_any is true the fence array signals if any fence in the array
- * signals, otherwise it signals when all fences in the array signal.
+ * Implementation of @dma_fence_array_create without allocation. Useful to init
+ * a preallocated dma fence array in the path of reclaim or dma fence signaling.
  */
-struct dma_fence_array *dma_fence_array_create(int num_fences,
-                                              struct dma_fence **fences,
-                                              u64 context, unsigned seqno,
-                                              bool signal_on_any)
+void dma_fence_array_init(struct dma_fence_array *array,
+                         int num_fences, struct dma_fence **fences,
+                         u64 context, unsigned seqno,
+                         bool signal_on_any)
 {
-       struct dma_fence_array *array;
-
        WARN_ON(!num_fences || !fences);
 
-       array = kzalloc(struct_size(array, callbacks, num_fences), GFP_KERNEL);
-       if (!array)
-               return NULL;
-
        array->num_fences = num_fences;
 
        spin_lock_init(&array->lock);
@@ -200,6 +201,41 @@ struct dma_fence_array *dma_fence_array_create(int num_fences,
         */
        while (num_fences--)
                WARN_ON(dma_fence_is_container(fences[num_fences]));
+}
+EXPORT_SYMBOL(dma_fence_array_init);
+
+/**
+ * dma_fence_array_create - Create a custom fence array
+ * @num_fences:                [in]    number of fences to add in the array
+ * @fences:            [in]    array containing the fences
+ * @context:           [in]    fence context to use
+ * @seqno:             [in]    sequence number to use
+ * @signal_on_any:     [in]    signal on any fence in the array
+ *
+ * Allocate a dma_fence_array object and initialize the base fence with
+ * dma_fence_init().
+ * In case of error it returns NULL.
+ *
+ * The caller should allocate the fences array with num_fences size
+ * and fill it with the fences it wants to add to the object. Ownership of this
+ * array is taken and dma_fence_put() is used on each fence on release.
+ *
+ * If @signal_on_any is true the fence array signals if any fence in the array
+ * signals, otherwise it signals when all fences in the array signal.
+ */
+struct dma_fence_array *dma_fence_array_create(int num_fences,
+                                              struct dma_fence **fences,
+                                              u64 context, unsigned seqno,
+                                              bool signal_on_any)
+{
+       struct dma_fence_array *array;
+
+       array = dma_fence_array_alloc(num_fences);
+       if (!array)
+               return NULL;
+
+       dma_fence_array_init(array, num_fences, fences,
+                            context, seqno, signal_on_any);
 
        return array;
 }

diff --git a/include/linux/dma-fence-array.h b/include/linux/dma-fence-array.h
index 29c5650c10384bb9bb6ed573e5c84ab6c46443d1..079b3dec0a16beb1205fbafd715347063a001470 100644 (file)
--- a/include/linux/dma-fence-array.h
+++ b/include/linux/dma-fence-array.h
@@ -79,6 +79,12 @@ to_dma_fence_array(struct dma_fence *fence)
        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_alloc(int num_fences);
+void dma_fence_array_init(struct dma_fence_array *array,
+                         int num_fences, struct dma_fence **fences,
+                         u64 context, unsigned seqno,
+                         bool signal_on_any);
+
 struct dma_fence_array *dma_fence_array_create(int num_fences,
                                               struct dma_fence **fences,
                                               u64 context, unsigned seqno,