1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2017 Intel Corporation
5 #ifndef _RTE_SERVICE_H_
6 #define _RTE_SERVICE_H_
13 * The service functionality provided by this header allows a DPDK component
14 * to indicate that it requires a function call in order for it to perform
17 * An example usage of this functionality would be a component that registers
18 * a service to perform a particular packet processing duty: for example the
19 * eventdev software PMD. At startup the application requests all services
20 * that have been registered, and the cores in the service-coremask run the
21 * required services. The EAL removes these number of cores from the available
22 * runtime cores, and dedicates them to performing service-core workloads. The
23 * application has access to the remaining lcores as normal.
32 #include <sys/queue.h>
34 #include <rte_config.h>
35 #include <rte_lcore.h>
37 #define RTE_SERVICE_NAME_MAX 32
39 /* Capabilities of a service.
41 * Use the *rte_service_probe_capability* function to check if a service is
42 * capable of a specific capability.
44 /** When set, the service is capable of having multiple threads run it at the
47 #define RTE_SERVICE_CAP_MT_SAFE (1 << 0)
50 * Return the number of services registered.
52 * The number of services registered can be passed to *rte_service_get_by_id*,
53 * enabling the application to retrieve the specification of each service.
55 * @return The number of services registered.
57 uint32_t rte_service_get_count(void);
60 * Return the id of a service by name.
62 * This function provides the id of the service using the service name as
63 * lookup key. The service id is to be passed to other functions in the
68 * uint32_t service_id;
69 * int32_t ret = rte_service_get_by_name("service_X", &service_id);
75 * @param name The name of the service to retrieve
76 * @param[out] service_id A pointer to a uint32_t, to be filled in with the id.
77 * @retval 0 Success. The service id is provided in *service_id*.
78 * @retval -EINVAL Null *service_id* pointer provided
79 * @retval -ENODEV No such service registered
81 int32_t rte_service_get_by_name(const char *name, uint32_t *service_id);
84 * Return the name of the service.
86 * @return A pointer to the name of the service. The returned pointer remains
87 * in ownership of the service, and the application must not free it.
89 const char *rte_service_get_name(uint32_t id);
92 * Check if a service has a specific capability.
94 * This function returns if *service* has implements *capability*.
95 * See RTE_SERVICE_CAP_* defines for a list of valid capabilities.
96 * @retval 1 Capability supported by this service instance
97 * @retval 0 Capability not supported by this service instance
99 int32_t rte_service_probe_capability(uint32_t id, uint32_t capability);
102 * Map or unmap a lcore to a service.
104 * Each core can be added or removed from running a specific service. This
105 * function enables or disables *lcore* to run *service_id*.
107 * If multiple cores are enabled on a service, a lock is used to ensure that
108 * only one core runs the service at a time. The exception to this is when
109 * a service indicates that it is multi-thread safe by setting the capability
110 * called RTE_SERVICE_CAP_MT_SAFE. With the multi-thread safe capability set,
111 * the service function can be run on multiple threads at the same time.
113 * If the service is known to be mapped to a single lcore, setting the
114 * capability of the service to RTE_SERVICE_CAP_MT_SAFE can achieve
115 * better performance by avoiding the use of lock.
117 * @param service_id the service to apply the lcore to
118 * @param lcore The lcore that will be mapped to service
119 * @param enable Zero to unmap or disable the core, non-zero to enable
121 * @retval 0 lcore map updated successfully
122 * @retval -EINVAL An invalid service or lcore was provided.
124 int32_t rte_service_map_lcore_set(uint32_t service_id, uint32_t lcore,
128 * Retrieve the mapping of an lcore to a service.
130 * @param service_id the service to apply the lcore to
131 * @param lcore The lcore that will be mapped to service
133 * @retval 1 lcore is mapped to service
134 * @retval 0 lcore is not mapped to service
135 * @retval -EINVAL An invalid service or lcore was provided.
137 int32_t rte_service_map_lcore_get(uint32_t service_id, uint32_t lcore);
140 * Set the runstate of the service.
142 * Each service is either running or stopped. Setting a non-zero runstate
143 * enables the service to run, while setting runstate zero disables it.
145 * @param id The id of the service
146 * @param runstate The run state to apply to the service
148 * @retval 0 The service was successfully started
149 * @retval -EINVAL Invalid service id
151 int32_t rte_service_runstate_set(uint32_t id, uint32_t runstate);
154 * Get the runstate for the service with *id*. See *rte_service_runstate_set*
155 * for details of runstates. A service can call this function to ensure that
156 * the application has indicated that it will receive CPU cycles. Either a
157 * service-core is mapped (default case), or the application has explicitly
158 * disabled the check that a service-cores is mapped to the service and takes
159 * responsibility to run the service manually using the available function
160 * *rte_service_run_iter_on_app_lcore* to do so.
162 * @retval 1 Service is running
163 * @retval 0 Service is stopped
164 * @retval -EINVAL Invalid service id
166 int32_t rte_service_runstate_get(uint32_t id);
169 * This function returns whether the service may be currently executing on
170 * at least one lcore, or definitely is not. This function can be used to
171 * determine if, after setting the service runstate to stopped, the service
172 * is still executing a service lcore.
174 * Care must be taken if calling this function when the service runstate is
175 * running, since the result of this function may be incorrect by the time the
176 * function returns due to service cores running in parallel.
178 * @retval 1 Service may be running on one or more lcores
179 * @retval 0 Service is not running on any lcore
180 * @retval -EINVAL Invalid service id
183 rte_service_may_be_active(uint32_t id);
186 * Enable or disable the check for a service-core being mapped to the service.
187 * An application can disable the check when takes the responsibility to run a
188 * service itself using *rte_service_run_iter_on_app_lcore*.
190 * @param id The id of the service to set the check on
191 * @param enable When zero, the check is disabled. Non-zero enables the check.
194 * @retval -EINVAL Invalid service ID
196 int32_t rte_service_set_runstate_mapped_check(uint32_t id, int32_t enable);
199 * This function runs a service callback from a non-service lcore.
201 * This function is designed to enable gradual porting to service cores, and
202 * to enable unit tests to verify a service behaves as expected.
204 * When called, this function ensures that the service identified by *id* is
205 * safe to run on this lcore. Multi-thread safe services are invoked even if
206 * other cores are simultaneously running them as they are multi-thread safe.
208 * Multi-thread unsafe services are handled depending on the variable
209 * *serialize_multithread_unsafe*:
210 * - When set, the function will check if a service is already being invoked
211 * on another lcore, refusing to run it and returning -EBUSY.
212 * - When zero, the application takes responsibility to ensure that the service
213 * indicated by *id* is not going to be invoked by another lcore. This setting
214 * avoids atomic operations, so is likely to be more performant.
216 * @param id The ID of the service to run
217 * @param serialize_multithread_unsafe This parameter indicates to the service
218 * cores library if it is required to use atomics to serialize access
219 * to mult-thread unsafe services. As there is an overhead in using
220 * atomics, applications can choose to enable or disable this feature
222 * Note that any thread calling this function MUST be a DPDK EAL thread, as
223 * the *rte_lcore_id* function is used to access internal data structures.
225 * @retval 0 Service was run on the calling thread successfully
226 * @retval -EBUSY Another lcore is executing the service, and it is not a
227 * multi-thread safe service, so the service was not run on this lcore
228 * @retval -ENOEXEC Service is not in a run-able state
229 * @retval -EINVAL Invalid service id
231 int32_t rte_service_run_iter_on_app_lcore(uint32_t id,
232 uint32_t serialize_multithread_unsafe);
235 * Start a service core.
237 * Starting a core makes the core begin polling. Any services assigned to it
238 * will be run as fast as possible. The application must ensure that the lcore
239 * is in a launchable state: e.g. call *rte_eal_lcore_wait* on the lcore_id
240 * before calling this function.
243 * @retval -EINVAL Failed to start core. The *lcore_id* passed in is not
244 * currently assigned to be a service core.
246 int32_t rte_service_lcore_start(uint32_t lcore_id);
249 * Stop a service core.
251 * Stopping a core makes the core become idle, but remains assigned as a
252 * service core. Note that the service lcore thread may not have returned from
253 * the service it is running when this API returns.
255 * The *rte_service_lcore_may_be_active* API can be used to check if the
256 * service lcore is * still active.
259 * @retval -EINVAL Invalid *lcore_id* provided
260 * @retval -EALREADY Already stopped core
261 * @retval -EBUSY Failed to stop core, as it would cause a service to not
262 * be run, as this is the only core currently running the service.
263 * The application must stop the service first, and then stop the
266 int32_t rte_service_lcore_stop(uint32_t lcore_id);
269 * Reports if a service lcore is currently running.
271 * This function returns if the core has finished service cores code, and has
272 * returned to EAL control. If *rte_service_lcore_stop* has been called but
273 * the lcore has not returned to EAL yet, it might be required to wait and call
274 * this function again. The amount of time to wait before the core returns
275 * depends on the duration of the services being run.
277 * @retval 0 Service thread is not active, and lcore has been returned to EAL.
278 * @retval 1 Service thread is in the service core polling loop.
279 * @retval -EINVAL Invalid *lcore_id* provided.
282 int32_t rte_service_lcore_may_be_active(uint32_t lcore_id);
285 * Adds lcore to the list of service cores.
287 * This functions can be used at runtime in order to modify the service core
291 * @retval -EBUSY lcore is busy, and not available for service core duty
292 * @retval -EALREADY lcore is already added to the service core list
293 * @retval -EINVAL Invalid lcore provided
295 int32_t rte_service_lcore_add(uint32_t lcore);
298 * Removes lcore from the list of service cores.
300 * This can fail if the core is not stopped, see *rte_service_core_stop*.
303 * @retval -EBUSY Lcore is not stopped, stop service core before removing.
304 * @retval -EINVAL failed to add lcore to service core mask.
306 int32_t rte_service_lcore_del(uint32_t lcore);
309 * Retrieve the number of service cores currently available.
311 * This function returns the integer count of service cores available. The
312 * service core count can be used in mapping logic when creating mappings
313 * from service cores to services.
315 * See *rte_service_lcore_list* for details on retrieving the lcore_id of each
318 * @return The number of service cores currently configured.
320 int32_t rte_service_lcore_count(void);
323 * Resets all service core mappings. This does not remove the service cores
324 * from duty, just unmaps all services / cores, and stops() the service cores.
325 * The runstate of services is not modified.
327 * The cores that are stopped with this call, are in FINISHED state and
328 * the application must take care of bringing them back to a launchable state:
329 * e.g. call *rte_eal_lcore_wait* on the lcore_id.
333 int32_t rte_service_lcore_reset_all(void);
336 * Enable or disable statistics collection for *service*.
338 * This function enables per core, per-service cycle count collection.
339 * @param id The service to enable statistics gathering on.
340 * @param enable Zero to disable statistics, non-zero to enable.
342 * @retval -EINVAL Invalid service pointer passed
344 int32_t rte_service_set_stats_enable(uint32_t id, int32_t enable);
347 * Retrieve the list of currently enabled service cores.
349 * This function fills in an application supplied array, with each element
350 * indicating the lcore_id of a service core.
352 * Adding and removing service cores can be performed using
353 * *rte_service_lcore_add* and *rte_service_lcore_del*.
354 * @param [out] array An array of at least *rte_service_lcore_count* items.
355 * If statically allocating the buffer, use RTE_MAX_LCORE.
356 * @param [out] n The size of *array*.
357 * @retval >=0 Number of service cores that have been populated in the array
358 * @retval -ENOMEM The provided array is not large enough to fill in the
359 * service core list. No items have been populated, call this function
360 * with a size of at least *rte_service_core_count* items.
362 int32_t rte_service_lcore_list(uint32_t array[], uint32_t n);
365 * Get the number of services running on the supplied lcore.
367 * @param lcore Id of the service core.
368 * @retval >=0 Number of services registered to this core.
369 * @retval -EINVAL Invalid lcore provided
370 * @retval -ENOTSUP The provided lcore is not a service core.
372 int32_t rte_service_lcore_count_services(uint32_t lcore);
375 * Dumps any information available about the service. When id is UINT32_MAX,
376 * this function dumps info for all services.
378 * @retval 0 Statistics have been successfully dumped
379 * @retval -EINVAL Invalid service id provided
381 int32_t rte_service_dump(FILE *f, uint32_t id);
384 * Returns the number of cycles that this service has consumed
386 #define RTE_SERVICE_ATTR_CYCLES 0
389 * Returns the count of invocations of this service function
391 #define RTE_SERVICE_ATTR_CALL_COUNT 1
394 * Get an attribute from a service.
396 * @retval 0 Success, the attribute value has been written to *attr_value*.
397 * -EINVAL Invalid id, attr_id or attr_value was NULL.
399 int32_t rte_service_attr_get(uint32_t id, uint32_t attr_id,
400 uint64_t *attr_value);
403 * Reset all attribute values of a service.
405 * @param id The service to reset all statistics of
406 * @retval 0 Successfully reset attributes
407 * -EINVAL Invalid service id provided
409 int32_t rte_service_attr_reset_all(uint32_t id);
412 * Returns the number of times the service runner has looped.
414 #define RTE_SERVICE_LCORE_ATTR_LOOPS 0
417 * Get an attribute from a service core.
419 * @param lcore Id of the service core.
420 * @param attr_id Id of the attribute to be retrieved.
421 * @param [out] attr_value Pointer to storage in which to write retrieved value.
422 * @retval 0 Success, the attribute value has been written to *attr_value*.
423 * -EINVAL Invalid lcore, attr_id or attr_value was NULL.
424 * -ENOTSUP lcore is not a service core.
427 rte_service_lcore_attr_get(uint32_t lcore, uint32_t attr_id,
428 uint64_t *attr_value);
431 * Reset all attribute values of a service core.
433 * @param lcore The service core to reset all the statistics of
434 * @retval 0 Successfully reset attributes
435 * -EINVAL Invalid service id provided
436 * -ENOTSUP lcore is not a service core.
439 rte_service_lcore_attr_reset_all(uint32_t lcore);
446 #endif /* _RTE_SERVICE_H_ */