accel: functions to iterate over tasks in a sequence

Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: I97f011b7eaa7db7e9a9df583aff23321d60bb72f
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/16378
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

include/spdk_internal/accel_module.h

@@ -236,4 +236,23 @@ bool spdk_accel_alloc_sequence_buf(struct spdk_accel_sequence *seq, void *buf,
 				   struct spdk_memory_domain *domain, void *domain_ctx,
 				   spdk_accel_sequence_get_buf_cb cb_fn, void *cb_ctx);
 
+/**
+ * Returns the first task remaining to be executed in a given sequence.
+ *
+ * \param seq Sequence object.
+ *
+ * \return the first remaining task or NULL if all tasks are already completed.
+ */
+struct spdk_accel_task *spdk_accel_sequence_first_task(struct spdk_accel_sequence *seq);
+
+/**
+ * Returns the next remaining task that follows a given task in a sequence.
+ *
+ * \param task Accel task.  This task must be still oustanding (i.e. it wasn't completed through
+ *             `spdk_accel_task_complete()`).
+ *
+ * \return the next task or NULL if `task` was the last task in a sequence.
+ */
+struct spdk_accel_task *spdk_accel_sequence_next_task(struct spdk_accel_task *task);
+
 #endif

lib/accel/accel.c

@@ -1253,6 +1253,18 @@ spdk_accel_alloc_sequence_buf(struct spdk_accel_sequence *seq, void *buf,
 	return true;
 }
 
+struct spdk_accel_task *
+spdk_accel_sequence_first_task(struct spdk_accel_sequence *seq)
+{
+	return TAILQ_FIRST(&seq->tasks);
+}
+
+struct spdk_accel_task *
+spdk_accel_sequence_next_task(struct spdk_accel_task *task)
+{
+	return TAILQ_NEXT(task, seq_link);
+}
+
 static inline uint64_t
 accel_get_iovlen(struct iovec *iovs, uint32_t iovcnt)
 {

lib/accel/spdk_accel.map

@@ -43,6 +43,8 @@
 	spdk_accel_driver_register;
 	spdk_accel_get_memory_domain;
 	spdk_accel_alloc_sequence_buf;
+	spdk_accel_sequence_first_task;
+	spdk_accel_sequence_next_task;
 
 	local: *;
 };