xref: /dpdk/lib/eventdev/rte_event_dma_adapter.h (revision edc13af9a8bbdca92bd8974165df2ff7049f45b7)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright (c) 2023 Marvell.
3  */
4 
5 #ifndef RTE_EVENT_DMA_ADAPTER
6 #define RTE_EVENT_DMA_ADAPTER
7 
8 /**
9  * @file rte_event_dma_adapter.h
10  *
11  * @warning
12  * @b EXPERIMENTAL:
13  * All functions in this file may be changed or removed without prior notice.
14  *
15  * DMA Event Adapter API.
16  *
17  * Eventdev library provides adapters to bridge between various components for providing new
18  * event source. The event DMA adapter is one of those adapters which is intended to bridge
19  * between event devices and DMA devices.
20  *
21  * The DMA adapter adds support to enqueue / dequeue DMA operations to / from event device. The
22  * packet flow between DMA device and the event device can be accomplished using both SW and HW
23  * based transfer mechanisms. The adapter uses an EAL service core function for SW based packet
24  * transfer and uses the eventdev PMD functions to configure HW based packet transfer between the
25  * DMA device and the event device.
26  *
27  * The application can choose to submit a DMA operation directly to an DMA device or send it to the
28  * DMA adapter via eventdev based on RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_OP_FWD capability. The
29  * first mode is known as the event new (RTE_EVENT_DMA_ADAPTER_OP_NEW) mode and the second as the
30  * event forward (RTE_EVENT_DMA_ADAPTER_OP_FORWARD) mode. The choice of mode can be specified while
31  * creating the adapter. In the former mode, it is an application responsibility to enable ingress
32  * packet ordering. In the latter mode, it is the adapter responsibility to enable the ingress
33  * packet ordering.
34  *
35  *
36  * Working model of RTE_EVENT_DMA_ADAPTER_OP_NEW mode:
37  *
38  *                +--------------+         +--------------+
39  *                |              |         |   DMA stage  |
40  *                | Application  |---[2]-->| + enqueue to |
41  *                |              |         |     dmadev   |
42  *                +--------------+         +--------------+
43  *                    ^   ^                       |
44  *                    |   |                      [3]
45  *                   [6] [1]                      |
46  *                    |   |                       |
47  *                +--------------+                |
48  *                |              |                |
49  *                | Event device |                |
50  *                |              |                |
51  *                +--------------+                |
52  *                       ^                        |
53  *                       |                        |
54  *                      [5]                       |
55  *                       |                        v
56  *                +--------------+         +--------------+
57  *                |              |         |              |
58  *                |  DMA adapter |<--[4]---|    dmadev    |
59  *                |              |         |              |
60  *                +--------------+         +--------------+
61  *
62  *
63  *         [1] Application dequeues events from the previous stage.
64  *         [2] Application prepares the DMA operations.
65  *         [3] DMA operations are submitted to dmadev by application.
66  *         [4] DMA adapter dequeues DMA completions from dmadev.
67  *         [5] DMA adapter enqueues events to the eventdev.
68  *         [6] Application dequeues from eventdev for further processing.
69  *
70  * In the RTE_EVENT_DMA_ADAPTER_OP_NEW mode, application submits DMA operations directly to DMA
71  * device. The DMA adapter then dequeues DMA completions from DMA device and enqueue events to the
72  * event device. This mode does not ensure ingress ordering, if the application directly enqueues
73  * to dmadev without going through DMA / atomic stage i.e. removing item [1] and [2].
74  *
75  * Events dequeued from the adapter will be treated as new events. In this mode, application needs
76  * to specify event information (response information) which is needed to enqueue an event after the
77  * DMA operation is completed.
78  *
79  *
80  * Working model of RTE_EVENT_DMA_ADAPTER_OP_FORWARD mode:
81  *
82  *                +--------------+         +--------------+
83  *        --[1]-->|              |---[2]-->|  Application |
84  *                | Event device |         |      in      |
85  *        <--[8]--|              |<--[3]---| Ordered stage|
86  *                +--------------+         +--------------+
87  *                    ^      |
88  *                    |     [4]
89  *                   [7]     |
90  *                    |      v
91  *               +----------------+       +--------------+
92  *               |                |--[5]->|              |
93  *               |   DMA adapter  |       |     dmadev   |
94  *               |                |<-[6]--|              |
95  *               +----------------+       +--------------+
96  *
97  *
98  *         [1] Events from the previous stage.
99  *         [2] Application in ordered stage dequeues events from eventdev.
100  *         [3] Application enqueues DMA operations as events to eventdev.
101  *         [4] DMA adapter dequeues event from eventdev.
102  *         [5] DMA adapter submits DMA operations to dmadev (Atomic stage).
103  *         [6] DMA adapter dequeues DMA completions from dmadev
104  *         [7] DMA adapter enqueues events to the eventdev
105  *         [8] Events to the next stage
106  *
107  * In the event forward (RTE_EVENT_DMA_ADAPTER_OP_FORWARD) mode, if the HW supports the capability
108  * RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_OP_FWD, application can directly submit the DMA
109  * operations to the dmadev. If not, application retrieves the event port of the DMA adapter
110  * through the API, rte_event_DMA_adapter_event_port_get(). Then, links its event queue to this
111  * port and starts enqueuing DMA operations as events to the eventdev. The adapter then dequeues
112  * the events and submits the DMA operations to the dmadev. After the DMA completions, the adapter
113  * enqueues events to the event device.
114  *
115  * Application can use this mode, when ingress packet ordering is needed. Events dequeued from the
116  * adapter will be treated as forwarded events. In this mode, the application needs to specify the
117  * dmadev ID and queue pair ID (request information) needed to enqueue an DMA operation in addition
118  * to the event information (response information) needed to enqueue an event after the DMA
119  * operation has completed.
120  *
121  * The event DMA adapter provides common APIs to configure the packet flow from the DMA device to
122  * event devices for both SW and HW based transfers. The DMA event adapter's functions are:
123  *
124  *  - rte_event_dma_adapter_create_ext()
125  *  - rte_event_dma_adapter_create()
126  *  - rte_event_dma_adapter_free()
127  *  - rte_event_dma_adapter_vchan_add()
128  *  - rte_event_dma_adapter_vchan_del()
129  *  - rte_event_dma_adapter_start()
130  *  - rte_event_dma_adapter_stop()
131  *  - rte_event_dma_adapter_stats_get()
132  *  - rte_event_dma_adapter_stats_reset()
133  *
134  * The application creates an instance using rte_event_dma_adapter_create() or
135  * rte_event_dma_adapter_create_ext().
136  *
137  * dmadev queue pair addition / deletion is done using the rte_event_dma_adapter_vchan_add() /
138  * rte_event_dma_adapter_vchan_del() APIs. If HW supports the capability
139  * RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_VCHAN_EV_BIND, event information must be passed to the
140  * add API.
141  *
142  */
143 
144 #include <stdint.h>
145 
146 #include <rte_common.h>
147 #include <rte_dmadev_pmd.h>
148 #include <rte_eventdev.h>
149 
150 #ifdef __cplusplus
151 extern "C" {
152 #endif
153 
154 /**
155  * A structure used to hold event based DMA operation entry. All the information
156  * required for a DMA transfer shall be populated in "struct rte_event_dma_adapter_op"
157  * instance.
158  */
159 struct rte_event_dma_adapter_op {
160 	struct rte_dma_sge *src_seg;
161 	/**< Source segments. */
162 	struct rte_dma_sge *dst_seg;
163 	/**< Destination segments. */
164 	uint16_t nb_src;
165 	/**< Number of source segments. */
166 	uint16_t nb_dst;
167 	/**< Number of destination segments. */
168 	uint64_t flags;
169 	/**< Flags related to the operation.
170 	 * @see RTE_DMA_OP_FLAG_*
171 	 */
172 	int16_t dma_dev_id;
173 	/**< DMA device ID to be used */
174 	uint16_t vchan;
175 	/**< DMA vchan ID to be used */
176 	struct rte_mempool *op_mp;
177 	/**< Mempool from which op is allocated. */
178 };
179 
180 /**
181  *  DMA event adapter mode
182  */
183 enum rte_event_dma_adapter_mode {
184 	RTE_EVENT_DMA_ADAPTER_OP_NEW,
185 	/**< Start the DMA adapter in event new mode.
186 	 * @see RTE_EVENT_OP_NEW.
187 	 *
188 	 * Application submits DMA operations to the dmadev. Adapter only dequeues the DMA
189 	 * completions from dmadev and enqueue events to the eventdev.
190 	 */
191 
192 	RTE_EVENT_DMA_ADAPTER_OP_FORWARD,
193 	/**< Start the DMA adapter in event forward mode.
194 	 * @see RTE_EVENT_OP_FORWARD.
195 	 *
196 	 * Application submits DMA requests as events to the DMA adapter or DMA device based on
197 	 * RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_OP_FWD capability. DMA completions are enqueued
198 	 * back to the eventdev by DMA adapter.
199 	 */
200 };
201 
202 /**
203  * Adapter configuration structure that the adapter configuration callback function is expected to
204  * fill out.
205  *
206  * @see rte_event_dma_adapter_conf_cb
207  */
208 struct rte_event_dma_adapter_conf {
209 	uint8_t event_port_id;
210 	/** < Event port identifier, the adapter enqueues events to this port and dequeues DMA
211 	 * request events in RTE_EVENT_DMA_ADAPTER_OP_FORWARD mode.
212 	 */
213 
214 	uint32_t max_nb;
215 	/**< The adapter can return early if it has processed at least max_nb DMA ops. This isn't
216 	 * treated as a requirement; batching may cause the adapter to process more than max_nb DMA
217 	 * ops.
218 	 */
219 };
220 
221 /**
222  * Adapter runtime configuration parameters
223  */
224 struct rte_event_dma_adapter_runtime_params {
225 	uint32_t max_nb;
226 	/**< The adapter can return early if it has processed at least max_nb DMA ops. This isn't
227 	 * treated as a requirement; batching may cause the adapter to process more than max_nb DMA
228 	 * ops.
229 	 *
230 	 * Callback function passed to rte_event_dma_adapter_create_ext() configures the adapter
231 	 * with default value of max_nb.
232 	 * rte_event_dma_adapter_runtime_params_set() allows to re-configure max_nb during runtime
233 	 * (after adding at least one queue pair)
234 	 *
235 	 * This is valid for the devices without RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_OP_FWD or
236 	 * RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_OP_NEW capability.
237 	 */
238 
239 	uint32_t rsvd[15];
240 	/**< Reserved fields for future expansion */
241 };
242 
243 /**
244  * Function type used for adapter configuration callback. The callback is used to fill in members of
245  * the struct rte_event_dma_adapter_conf, this callback is invoked when creating a SW service for
246  * packet transfer from dmadev vchan to the event device. The SW service is created within the
247  * function, rte_event_dma_adapter_vchan_add(), if SW based packet transfers from dmadev vchan
248  * to the event device are required.
249  *
250  * @param id
251  *     Adapter identifier.
252  * @param evdev_id
253  *     Event device identifier.
254  * @param conf
255  *     Structure that needs to be populated by this callback.
256  * @param arg
257  *     Argument to the callback. This is the same as the conf_arg passed to the
258  * rte_event_dma_adapter_create_ext().
259  */
260 typedef int (*rte_event_dma_adapter_conf_cb)(uint8_t id, uint8_t evdev_id,
261 					     struct rte_event_dma_adapter_conf *conf, void *arg);
262 
263 /**
264  * A structure used to retrieve statistics for an event DMA adapter instance.
265  */
266 struct rte_event_dma_adapter_stats {
267 	uint64_t event_poll_count;
268 	/**< Event port poll count */
269 
270 	uint64_t event_deq_count;
271 	/**< Event dequeue count */
272 
273 	uint64_t dma_enq_count;
274 	/**< dmadev enqueue count */
275 
276 	uint64_t dma_enq_fail_count;
277 	/**< dmadev enqueue failed count */
278 
279 	uint64_t dma_deq_count;
280 	/**< dmadev dequeue count */
281 
282 	uint64_t event_enq_count;
283 	/**< Event enqueue count */
284 
285 	uint64_t event_enq_retry_count;
286 	/**< Event enqueue retry count */
287 
288 	uint64_t event_enq_fail_count;
289 	/**< Event enqueue fail count */
290 };
291 
292 /**
293  * Create a new event DMA adapter with the specified identifier.
294  *
295  * @param id
296  *     Adapter identifier.
297  * @param evdev_id
298  *     Event device identifier.
299  * @param conf_cb
300  *     Callback function that fills in members of a struct rte_event_dma_adapter_conf struct passed
301  * into it.
302  * @param mode
303  *     Flag to indicate the mode of the adapter.
304  *     @see rte_event_dma_adapter_mode
305  * @param conf_arg
306  *     Argument that is passed to the conf_cb function.
307  *
308  * @return
309  *     - 0: Success
310  *     - <0: Error code on failure
311  */
312 __rte_experimental
313 int rte_event_dma_adapter_create_ext(uint8_t id, uint8_t evdev_id,
314 				     rte_event_dma_adapter_conf_cb conf_cb,
315 				     enum rte_event_dma_adapter_mode mode, void *conf_arg);
316 
317 /**
318  * Create a new event DMA adapter with the specified identifier. This function uses an internal
319  * configuration function that creates an event port. This default function reconfigures the event
320  * device with an additional event port and set up the event port using the port_config parameter
321  * passed into this function. In case the application needs more control in configuration of the
322  * service, it should use the rte_event_dma_adapter_create_ext() version.
323  *
324  * @param id
325  *     Adapter identifier.
326  * @param evdev_id
327  *     Event device identifier.
328  * @param port_config
329  *     Argument of type *rte_event_port_conf* that is passed to the conf_cb function.
330  * @param mode
331  *     Flag to indicate the mode of the adapter.
332  *     @see rte_event_dma_adapter_mode
333  *
334  * @return
335  *     - 0: Success
336  *     - <0: Error code on failure
337  */
338 __rte_experimental
339 int rte_event_dma_adapter_create(uint8_t id, uint8_t evdev_id,
340 				 struct rte_event_port_conf *port_config,
341 				 enum rte_event_dma_adapter_mode mode);
342 
343 /**
344  * Free an event DMA adapter
345  *
346  * @param id
347  *     Adapter identifier.
348  * @return
349  *     - 0: Success
350  *     - <0: Error code on failure, If the adapter still has queue pairs added to it, the function
351  * returns -EBUSY.
352  */
353 __rte_experimental
354 int rte_event_dma_adapter_free(uint8_t id);
355 
356 /**
357  * Retrieve the event port of an adapter.
358  *
359  * @param id
360  *     Adapter identifier.
361  *
362  * @param [out] event_port_id
363  *     Application links its event queue to this adapter port which is used in
364  * RTE_EVENT_DMA_ADAPTER_OP_FORWARD mode.
365  *
366  * @return
367  *     - 0: Success
368  *     - <0: Error code on failure.
369  */
370 __rte_experimental
371 int rte_event_dma_adapter_event_port_get(uint8_t id, uint8_t *event_port_id);
372 
373 /**
374  * Add a vchan to an event DMA adapter.
375  *
376  * @param id
377  *     Adapter identifier.
378  * @param dmadev_id
379  *     dmadev identifier.
380  * @param vchan
381  *     DMA device vchan identifier. If vchan is set -1, adapter adds all the
382  * preconfigured vchan to the instance.
383  * @param event
384  *     If HW supports dmadev vchan to event queue binding, application is expected to fill in
385  * event information, else it will be NULL.
386  *     @see RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_VCHAN_EV_BIND
387  *
388  * @return
389  *     - 0: Success, vchan added correctly.
390  *     - <0: Error code on failure.
391  */
392 __rte_experimental
393 int rte_event_dma_adapter_vchan_add(uint8_t id, int16_t dmadev_id, uint16_t vchan,
394 				    const struct rte_event *event);
395 
396 /**
397  * Delete a vchan from an event DMA adapter.
398  *
399  * @param id
400  *     Adapter identifier.
401  * @param dmadev_id
402  *     DMA device identifier.
403  * @param vchan
404  *     DMA device vchan identifier.
405  *
406  * @return
407  *     - 0: Success, vchan deleted successfully.
408  *     - <0: Error code on failure.
409  */
410 __rte_experimental
411 int rte_event_dma_adapter_vchan_del(uint8_t id, int16_t dmadev_id, uint16_t vchan);
412 
413 /**
414  * Retrieve the service ID of an adapter. If the adapter doesn't use a rte_service function, this
415  * function returns -ESRCH.
416  *
417  * @param id
418  *     Adapter identifier.
419  * @param [out] service_id
420  *     A pointer to a uint32_t, to be filled in with the service id.
421  *
422  * @return
423  *     - 0: Success
424  *     - <0: Error code on failure, if the adapter doesn't use a rte_service function, this function
425  * returns -ESRCH.
426  */
427 __rte_experimental
428 int rte_event_dma_adapter_service_id_get(uint8_t id, uint32_t *service_id);
429 
430 /**
431  * Start event DMA adapter
432  *
433  * @param id
434  *     Adapter identifier.
435  *
436  * @return
437  *     - 0: Success, adapter started successfully.
438  *     - <0: Error code on failure.
439  *
440  * @note The eventdev and dmadev to which the event_dma_adapter is connected should be started
441  * before calling rte_event_dma_adapter_start().
442  */
443 __rte_experimental
444 int rte_event_dma_adapter_start(uint8_t id);
445 
446 /**
447  * Stop event DMA adapter
448  *
449  * @param id
450  *  Adapter identifier.
451  *
452  * @return
453  *  - 0: Success, adapter stopped successfully.
454  *  - <0: Error code on failure.
455  */
456 __rte_experimental
457 int rte_event_dma_adapter_stop(uint8_t id);
458 
459 /**
460  * Initialize the adapter runtime configuration parameters
461  *
462  * @param params
463  *  A pointer to structure of type struct rte_event_dma_adapter_runtime_params
464  *
465  * @return
466  *  -  0: Success
467  *  - <0: Error code on failure
468  */
469 __rte_experimental
470 int rte_event_dma_adapter_runtime_params_init(struct rte_event_dma_adapter_runtime_params *params);
471 
472 /**
473  * Set the adapter runtime configuration parameters
474  *
475  * @param id
476  *  Adapter identifier
477  *
478  * @param params
479  *  A pointer to structure of type struct rte_event_dma_adapter_runtime_params with configuration
480  * parameter values. The reserved fields of this structure must be initialized to zero and the valid
481  * fields need to be set appropriately. This struct can be initialized using
482  * rte_event_dma_adapter_runtime_params_init() API to default values or application may reset this
483  * struct and update required fields.
484  *
485  * @return
486  *  -  0: Success
487  *  - <0: Error code on failure
488  */
489 __rte_experimental
490 int rte_event_dma_adapter_runtime_params_set(uint8_t id,
491 					     struct rte_event_dma_adapter_runtime_params *params);
492 
493 /**
494  * Get the adapter runtime configuration parameters
495  *
496  * @param id
497  *  Adapter identifier
498  *
499  * @param[out] params
500  *  A pointer to structure of type struct rte_event_dma_adapter_runtime_params containing valid
501  * adapter parameters when return value is 0.
502  *
503  * @return
504  *  -  0: Success
505  *  - <0: Error code on failure
506  */
507 __rte_experimental
508 int rte_event_dma_adapter_runtime_params_get(uint8_t id,
509 					     struct rte_event_dma_adapter_runtime_params *params);
510 
511 /**
512  * Retrieve statistics for an adapter
513  *
514  * @param id
515  *     Adapter identifier.
516  * @param [out] stats
517  *     A pointer to structure used to retrieve statistics for an adapter.
518  *
519  * @return
520  *     - 0: Success, retrieved successfully.
521  *     - <0: Error code on failure.
522  */
523 __rte_experimental
524 int rte_event_dma_adapter_stats_get(uint8_t id, struct rte_event_dma_adapter_stats *stats);
525 
526 /**
527  * Reset statistics for an adapter.
528  *
529  * @param id
530  *     Adapter identifier.
531  *
532  * @return
533  *     - 0: Success, statistics reset successfully.
534  *     - <0: Error code on failure.
535  */
536 __rte_experimental
537 int rte_event_dma_adapter_stats_reset(uint8_t id);
538 
539 /**
540  * Enqueue a burst of DMA operations as event objects supplied in *rte_event* structure on an event
541  * DMA adapter designated by its event *evdev_id* through the event port specified by *port_id*.
542  * This function is supported if the eventdev PMD has the
543  * #RTE_EVENT_DMA_ADAPTER_CAP_INTERNAL_PORT_OP_FWD capability flag set.
544  *
545  * The *nb_events* parameter is the number of event objects to enqueue that are supplied in the
546  * *ev* array of *rte_event* structure.
547  *
548  * The rte_event_dma_adapter_enqueue() function returns the number of event objects it actually
549  * enqueued. A return value equal to *nb_events* means that all event objects have been enqueued.
550  *
551  * @param evdev_id
552  *     The identifier of the device.
553  * @param port_id
554  *     The identifier of the event port.
555  * @param ev
556  *     Points to an array of *nb_events* objects of type *rte_event* structure which contain the
557  * event object enqueue operations to be processed.
558  * @param nb_events
559  *     The number of event objects to enqueue, typically number of
560  * rte_event_port_attr_get(...RTE_EVENT_PORT_ATTR_ENQ_DEPTH...) available for this port.
561  *
562  * @return
563  *     The number of event objects actually enqueued on the event device. The return value can be
564  * less than the value of the *nb_events* parameter when the event devices queue is full or if
565  * invalid parameters are specified in a *rte_event*. If the return value is less than *nb_events*,
566  * the remaining events at the end of ev[] are not consumed and the caller has to take care of them,
567  * and rte_errno is set accordingly. Possible errno values include:
568  *     - EINVAL: The port ID is invalid, device ID is invalid, an event's queue ID is invalid, or an
569  * event's sched type doesn't match the capabilities of the destination queue.
570  *     - ENOSPC: The event port was backpressured and unable to enqueue one or more events. This
571  * error code is only applicable to closed systems.
572  */
573 __rte_experimental
574 uint16_t rte_event_dma_adapter_enqueue(uint8_t evdev_id, uint8_t port_id, struct rte_event ev[],
575 				       uint16_t nb_events);
576 
577 #ifdef __cplusplus
578 }
579 #endif
580 
581 #endif /* RTE_EVENT_DMA_ADAPTER */
582