eventdev: add event port pre-schedule modify

Some event devices allow pre-schedule types to be modified at
runtime on an event port.
Add `RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE` capability
to indicate that the event device supports this feature.

Add `rte_event_port_preschedule_modify()` API to modify the
pre-schedule type at runtime.
To avoid fastpath capability checks, the API reports -ENOTSUP
if the event device does not support this feature.

Signed-off-by: Pavan Nikhilesh <[email protected]>
Acked-by: Jerin Jacob <[email protected]>

app/test/test_eventdev.c

@@ -1252,7 +1252,8 @@ test_eventdev_profile_switch(void)
 }
 
 static int
-preschedule_test(enum rte_event_dev_preschedule_type preschedule_type, const char *preschedule_name)
+preschedule_test(enum rte_event_dev_preschedule_type preschedule_type, const char *preschedule_name,
+		 uint8_t modify)
 {
 #define NB_EVENTS     1024
 	uint64_t start, total;
@@ -1270,7 +1271,11 @@ preschedule_test(enum rte_event_dev_preschedule_type preschedule_type, const cha
 		TEST_ASSERT(rc == 1, "Failed to enqueue event");
 	}
 
-	RTE_SET_USED(preschedule_type);
+	if (modify) {
+		rc = rte_event_port_preschedule_modify(TEST_DEV_ID, 0, preschedule_type);
+		TEST_ASSERT_SUCCESS(rc, "Failed to modify preschedule type");
+	}
+
 	total = 0;
 	while (cnt) {
 		start = rte_rdtsc_precise();
@@ -1335,28 +1340,56 @@ test_eventdev_preschedule_configure(void)
 
 	rc = preschedule_configure(RTE_EVENT_PRESCHEDULE_NONE, &info);
 	TEST_ASSERT_SUCCESS(rc, "Failed to configure eventdev");
-	rc = preschedule_test(RTE_EVENT_PRESCHEDULE_NONE, "RTE_EVENT_PRESCHEDULE_NONE");
+	rc = preschedule_test(RTE_EVENT_PRESCHEDULE_NONE, "RTE_EVENT_PRESCHEDULE_NONE", 0);
 	TEST_ASSERT_SUCCESS(rc, "Failed to test preschedule RTE_EVENT_PRESCHEDULE_NONE");
 
 	rte_event_dev_stop(TEST_DEV_ID);
 	rc = preschedule_configure(RTE_EVENT_PRESCHEDULE, &info);
 	TEST_ASSERT_SUCCESS(rc, "Failed to configure eventdev");
-	rc = preschedule_test(RTE_EVENT_PRESCHEDULE, "RTE_EVENT_PRESCHEDULE");
+	rc = preschedule_test(RTE_EVENT_PRESCHEDULE, "RTE_EVENT_PRESCHEDULE", 0);
 	TEST_ASSERT_SUCCESS(rc, "Failed to test preschedule RTE_EVENT_PRESCHEDULE");
 
 	if (info.event_dev_cap & RTE_EVENT_DEV_CAP_EVENT_PRESCHEDULE_ADAPTIVE) {
 		rte_event_dev_stop(TEST_DEV_ID);
 		rc = preschedule_configure(RTE_EVENT_PRESCHEDULE_ADAPTIVE, &info);
 		TEST_ASSERT_SUCCESS(rc, "Failed to configure eventdev");
 		rc = preschedule_test(RTE_EVENT_PRESCHEDULE_ADAPTIVE,
-				      "RTE_EVENT_PRESCHEDULE_ADAPTIVE");
+				      "RTE_EVENT_PRESCHEDULE_ADAPTIVE", 0);
 		TEST_ASSERT_SUCCESS(rc,
 				    "Failed to test preschedule RTE_EVENT_PRESCHEDULE_ADAPTIVE");
 	}
 
 	return TEST_SUCCESS;
 }
 
+static int
+test_eventdev_preschedule_modify(void)
+{
+	struct rte_event_dev_info info;
+	int rc;
+
+	rte_event_dev_info_get(TEST_DEV_ID, &info);
+	if ((info.event_dev_cap & RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE) == 0)
+		return TEST_SKIPPED;
+
+	rc = preschedule_configure(RTE_EVENT_PRESCHEDULE_NONE, &info);
+	TEST_ASSERT_SUCCESS(rc, "Failed to configure eventdev");
+	rc = preschedule_test(RTE_EVENT_PRESCHEDULE_NONE, "RTE_EVENT_PRESCHEDULE_NONE", 1);
+	TEST_ASSERT_SUCCESS(rc, "Failed to test per port preschedule RTE_EVENT_PRESCHEDULE_NONE");
+
+	rc = preschedule_test(RTE_EVENT_PRESCHEDULE, "RTE_EVENT_PRESCHEDULE", 1);
+	TEST_ASSERT_SUCCESS(rc, "Failed to test per port preschedule RTE_EVENT_PRESCHEDULE");
+
+	if (info.event_dev_cap & RTE_EVENT_DEV_CAP_EVENT_PRESCHEDULE_ADAPTIVE) {
+		rc = preschedule_test(RTE_EVENT_PRESCHEDULE_ADAPTIVE,
+				      "RTE_EVENT_PRESCHEDULE_ADAPTIVE", 1);
+		TEST_ASSERT_SUCCESS(
+			rc, "Failed to test per port preschedule RTE_EVENT_PRESCHEDULE_ADAPTIVE");
+	}
+
+	return TEST_SUCCESS;
+}
+
 static int
 test_eventdev_close(void)
 {
@@ -1419,6 +1452,8 @@ static struct unit_test_suite eventdev_common_testsuite  = {
 			test_eventdev_profile_switch),
 		TEST_CASE_ST(eventdev_configure_setup, NULL,
 			test_eventdev_preschedule_configure),
+		TEST_CASE_ST(eventdev_configure_setup, eventdev_stop_device,
+			test_eventdev_preschedule_modify),
 		TEST_CASE_ST(eventdev_setup_device, eventdev_stop_device,
 			test_eventdev_link),
 		TEST_CASE_ST(eventdev_setup_device, eventdev_stop_device,

doc/guides/prog_guide/eventdev/eventdev.rst

@@ -382,6 +382,22 @@ The following pre-schedule types are supported:
  * ``RTE_EVENT_PRESCHEDULE_ADAPTIVE`` - Issue pre-schedule when dequeue is issued
    and there are no forward progress constraints.
 
+Event devices that support ``RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE`` capability
+allow applications to modify pre-scheduling at a per port level at runtime in fast-path.
+To modify event pre-scheduling at a given event port,
+the application can use ``rte_event_port_preschedule_modify()`` API.
+This API can be called even if the event device does not support per port pre-scheduling,
+it will be treated as a no-op.
+
+.. code-block:: c
+
+   rte_event_port_preschedule_modify(dev_id, port_id, RTE_EVENT_PRESCHEDULE);
+   // Dequeue events from the event port with normal dequeue() function.
+   rte_event_port_preschedule_modify(dev_id, port_id, RTE_EVENT_PRESCHEDULE_NONE);
+   // Disable pre-scheduling if thread is about to be scheduled out
+   // and issue dequeue() to drain pending events.
+
+
 Starting the EventDev
 ~~~~~~~~~~~~~~~~~~~~~
 

doc/guides/rel_notes/release_24_11.rst

@@ -90,6 +90,9 @@ New Features
   * Added ``rte_event_dev_config::preschedule_type``
     to configure the device level pre-scheduling type.
 
+  * Added ``rte_event_port_preschedule_modify``
+    to modify pre-scheduling type on a given event port.
+
 * **Updated event device library for independent enqueue feature.**
 
   Added support for independent enqueue feature.

lib/eventdev/eventdev_pmd.h

@@ -184,6 +184,8 @@ struct __rte_cache_aligned rte_eventdev {
 	/**< Pointer to PMD DMA adapter enqueue function. */
 	event_profile_switch_t profile_switch;
 	/**< Pointer to PMD Event switch profile function. */
+	event_preschedule_modify_t preschedule_modify;
+	/**< Pointer to PMD Event port pre-schedule type modify function.  */
 
 	uint64_t reserved_64s[3]; /**< Reserved for future fields */
 	void *reserved_ptrs[3];	  /**< Reserved for future fields */

lib/eventdev/eventdev_private.c

@@ -96,6 +96,21 @@ dummy_event_port_profile_switch(__rte_unused void *port, __rte_unused uint8_t pr
 	return -EINVAL;
 }
 
+static int
+dummy_event_port_preschedule_modify(__rte_unused void *port,
+				    __rte_unused enum rte_event_dev_preschedule_type preschedule)
+{
+	RTE_EDEV_LOG_ERR("modify pre-schedule requested for unconfigured event device");
+	return -EINVAL;
+}
+
+static int
+dummy_event_port_preschedule_modify_hint(
+	__rte_unused void *port, __rte_unused enum rte_event_dev_preschedule_type preschedule)
+{
+	return -ENOTSUP;
+}
+
 void
 event_dev_fp_ops_reset(struct rte_event_fp_ops *fp_op)
 {
@@ -114,6 +129,7 @@ event_dev_fp_ops_reset(struct rte_event_fp_ops *fp_op)
 		.ca_enqueue = dummy_event_crypto_adapter_enqueue,
 		.dma_enqueue = dummy_event_dma_adapter_enqueue,
 		.profile_switch = dummy_event_port_profile_switch,
+		.preschedule_modify = dummy_event_port_preschedule_modify,
 		.data = dummy_data,
 	};
 
@@ -136,5 +152,9 @@ event_dev_fp_ops_set(struct rte_event_fp_ops *fp_op,
 	fp_op->ca_enqueue = dev->ca_enqueue;
 	fp_op->dma_enqueue = dev->dma_enqueue;
 	fp_op->profile_switch = dev->profile_switch;
+	fp_op->preschedule_modify = dev->preschedule_modify;
 	fp_op->data = dev->data->ports;
+
+	if (fp_op->preschedule_modify == NULL)
+		fp_op->preschedule_modify = dummy_event_port_preschedule_modify_hint;
 }

lib/eventdev/eventdev_trace_points.c

@@ -49,6 +49,9 @@ RTE_TRACE_POINT_REGISTER(rte_eventdev_trace_maintain,
 RTE_TRACE_POINT_REGISTER(rte_eventdev_trace_port_profile_switch,
 	lib.eventdev.port.profile.switch)
 
+RTE_TRACE_POINT_REGISTER(rte_eventdev_trace_port_preschedule_modify,
+	lib.eventdev.port.preschedule.modify)
+
 /* Eventdev Rx adapter trace points */
 RTE_TRACE_POINT_REGISTER(rte_eventdev_trace_eth_rx_adapter_create,
 	lib.eventdev.rx.adapter.create)

lib/eventdev/rte_eventdev.h

@@ -485,6 +485,16 @@ struct rte_event;
  * @see rte_event_dev_configure()
  */
 
+#define RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE (1ULL << 19)
+/**< Event device supports event pre-scheduling per event port.
+ *
+ * When this flag is set, the event device allows controlling the event
+ * pre-scheduling at a event port granularity.
+ *
+ * @see rte_event_dev_configure()
+ * @see rte_event_port_preschedule_modify()
+ */
+
 /* Event device priority levels */
 #define RTE_EVENT_DEV_PRIORITY_HIGHEST   0
 /**< Highest priority level for events and queues.
@@ -724,18 +734,23 @@ enum rte_event_dev_preschedule_type {
 	RTE_EVENT_PRESCHEDULE_NONE,
 	/**< Disable pre-schedule across the event device or on a given event port.
 	 * @ref rte_event_dev_config.preschedule_type
+	 * @ref rte_event_port_preschedule_modify()
 	 */
 	RTE_EVENT_PRESCHEDULE,
 	/**< Enable pre-schedule always across the event device or a given event port.
 	 * @ref rte_event_dev_config.preschedule_type
+	 * @ref rte_event_port_preschedule_modify()
 	 * @see RTE_EVENT_DEV_CAP_EVENT_PRESCHEDULE
+	 * @see RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE
 	 */
 	RTE_EVENT_PRESCHEDULE_ADAPTIVE,
 	/**< Enable adaptive pre-schedule across the event device or a given event port.
 	 * Delay issuing pre-schedule until there are no forward progress constraints with
 	 * the held flow contexts.
 	 * @ref rte_event_dev_config.preschedule_type
+	 * @ref rte_event_port_preschedule_modify()
 	 * @see RTE_EVENT_DEV_CAP_EVENT_PRESCHEDULE_ADAPTIVE
+	 * @see RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE
 	 */
 };
 
@@ -2954,6 +2969,52 @@ rte_event_port_profile_switch(uint8_t dev_id, uint8_t port_id, uint8_t profile_i
 	return fp_ops->profile_switch(port, profile_id);
 }
 
+/**
+ * Modify the pre-schedule type to use on an event port.
+ *
+ * This function is used to change the current pre-schedule type configured
+ * on an event port, the pre-schedule type can be set to none to disable pre-scheduling.
+ * This effects the subsequent ``rte_event_dequeue_burst`` call.
+ * The event device should support RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE capability.
+ *
+ * To avoid fastpath capability checks if an event device does not support
+ * RTE_EVENT_DEV_CAP_PER_PORT_PRESCHEDULE capability, then this function will
+ * return -ENOTSUP.
+ *
+ * @param dev_id
+ *   The identifier of the device.
+ * @param port_id
+ *   The identifier of the event port.
+ * @param type
+ *   The preschedule type to use on the event port.
+ * @return
+ *  - 0 on success.
+ *  - -EINVAL if *dev_id*,  *port_id*, or *type* is invalid.
+ *  - -ENOTSUP if the device does not support per port preschedule capability.
+ */
+__rte_experimental
+static inline int
+rte_event_port_preschedule_modify(uint8_t dev_id, uint8_t port_id,
+				  enum rte_event_dev_preschedule_type type)
+{
+	const struct rte_event_fp_ops *fp_ops;
+	void *port;
+
+	fp_ops = &rte_event_fp_ops[dev_id];
+	port = fp_ops->data[port_id];
+
+#ifdef RTE_LIBRTE_EVENTDEV_DEBUG
+	if (dev_id >= RTE_EVENT_MAX_DEVS || port_id >= RTE_EVENT_MAX_PORTS_PER_DEV)
+		return -EINVAL;
+
+	if (port == NULL)
+		return -EINVAL;
+#endif
+	rte_eventdev_trace_port_preschedule_modify(dev_id, port_id, type);
+
+	return fp_ops->preschedule_modify(port, type);
+}
+
 #ifdef __cplusplus
 }
 #endif

lib/eventdev/rte_eventdev_core.h

@@ -49,6 +49,10 @@ typedef uint16_t (*event_dma_adapter_enqueue_t)(void *port, struct rte_event ev[
 typedef int (*event_profile_switch_t)(void *port, uint8_t profile);
 /**< @internal Switch active link profile on the event port. */
 
+typedef int (*event_preschedule_modify_t)(void *port,
+					  enum rte_event_dev_preschedule_type preschedule_type);
+/**< @internal Modify pre-schedule type on the event port. */
+
 struct __rte_cache_aligned rte_event_fp_ops {
 	void **data;
 	/**< points to array of internal port data pointers */
@@ -76,7 +80,9 @@ struct __rte_cache_aligned rte_event_fp_ops {
 	/**< PMD DMA adapter enqueue function. */
 	event_profile_switch_t profile_switch;
 	/**< PMD Event switch profile function. */
-	uintptr_t reserved[4];
+	event_preschedule_modify_t preschedule_modify;
+	/**< PMD Event port pre-schedule switch. */
+	uintptr_t reserved[3];
 };
 
 extern struct rte_event_fp_ops rte_event_fp_ops[RTE_EVENT_MAX_DEVS];

lib/eventdev/rte_eventdev_trace_fp.h

@@ -8,7 +8,7 @@
 /**
  * @file
  *
- * API for ethdev trace support
+ * API for eventdev trace support
  */
 
 #include <rte_trace_point.h>
@@ -54,6 +54,15 @@ RTE_TRACE_POINT_FP(
 	rte_trace_point_emit_u8(profile);
 )
 
+RTE_TRACE_POINT_FP(
+	rte_eventdev_trace_port_preschedule_modify,
+	RTE_TRACE_POINT_ARGS(uint8_t dev_id, uint8_t port_id,
+			     int type),
+	rte_trace_point_emit_u8(dev_id);
+	rte_trace_point_emit_u8(port_id);
+	rte_trace_point_emit_int(type);
+)
+
 RTE_TRACE_POINT_FP(
 	rte_eventdev_trace_eth_tx_adapter_enqueue,
 	RTE_TRACE_POINT_ARGS(uint8_t dev_id, uint8_t port_id, void *ev_table,

lib/eventdev/version.map

@@ -147,6 +147,10 @@ EXPERIMENTAL {
 	rte_event_port_profile_unlink;
 	rte_event_port_profile_links_get;
 	__rte_eventdev_trace_port_profile_switch;
+
+	# added in 24.11
+	rte_event_port_preschedule_modify;
+	__rte_eventdev_trace_port_preschedule_modify;
 };
 
 INTERNAL {