[RFC,UPDATE,6/9] dmadev: allow NULL parameters to completed ops call
Checks
Commit Message
Allow the user to skip passing the "out" parameters to the
rte_dmadev_completed() API call, by using local replacements in the
inline function. This simplifies drivers, and compilers should be able
to remove the branches at compile time in many cases.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
lib/dmadev/rte_dmadev.h | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
@@ -698,9 +698,11 @@ rte_dmadev_perform(uint16_t dev_id, uint16_t vq_id)
* @param nb_cpls
* The maximum number of completed operations that can be processed.
* @param[out] last_idx
- * The last completed operation's index, as returned when entry was enqueued
+ * The last completed operation's index, as returned when entry was enqueued.
+ * If not required, NULL can be passed in.
* @param[out] has_error
* Indicates if there are transfer error.
+ * If not required, may be passed as NULL.
*
* @return
* The number of operations that successful completed.
@@ -714,7 +716,20 @@ rte_dmadev_completed(uint16_t dev_id, uint16_t vq_id, const uint16_t nb_cpls,
uint16_t *last_idx, bool *has_error)
{
struct rte_dmadev *dev = &rte_dmadevices[dev_id];
- has_error = false;
+ bool err = false;
+ uint16_t idx;
+
+ /* ensure the pointer values are non-null to simplify drivers.
+ * In most cases these should be compile time evaluated, since this is an inline function.
+ * - If NULL is explicitly passed as parameter, then compiler knows the value is NULL
+ * - If address of local variable is passed as parameter, then compiler can
+ * know it's non-NULL.
+ */
+ if (has_error == NULL)
+ has_error = &err;
+ if (last_idx == NULL)
+ last_idx = &idx;
+
return (*dev->completed)(dev, vq_id, nb_cpls, last_idx, has_error);
}