1 /* SPDX-License-Identifier: BSD-3-Clause 2 * Copyright(c) 2017 Intel Corporation 3 */ 4 5 #ifndef _RTE_SERVICE_H_ 6 #define _RTE_SERVICE_H_ 7 8 /** 9 * @file 10 * 11 * Service functions 12 * 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 15 * its processing. 16 * 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. 24 */ 25 26 #ifdef __cplusplus 27 extern "C" { 28 #endif 29 30 #include<stdio.h> 31 #include <stdint.h> 32 #include <sys/queue.h> 33 34 #include <rte_config.h> 35 #include <rte_lcore.h> 36 37 #define RTE_SERVICE_NAME_MAX 32 38 39 /* Capabilities of a service. 40 * 41 * Use the *rte_service_probe_capability* function to check if a service is 42 * capable of a specific capability. 43 */ 44 /** When set, the service is capable of having multiple threads run it at the 45 * same time. 46 */ 47 #define RTE_SERVICE_CAP_MT_SAFE (1 << 0) 48 49 /** 50 * Return the number of services registered. 51 * 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. 54 * 55 * @return The number of services registered. 56 */ 57 uint32_t rte_service_get_count(void); 58 59 /** 60 * Return the id of a service by name. 61 * 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 64 * rte_service_* API. 65 * 66 * Example usage: 67 * @code 68 * uint32_t service_id; 69 * int32_t ret = rte_service_get_by_name("service_X", &service_id); 70 * if (ret) { 71 * // handle error 72 * } 73 * @endcode 74 * 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 80 */ 81 int32_t rte_service_get_by_name(const char *name, uint32_t *service_id); 82 83 /** 84 * Return the name of the service. 85 * 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. 88 */ 89 const char *rte_service_get_name(uint32_t id); 90 91 /** 92 * Check if a service has a specific capability. 93 * 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 98 */ 99 int32_t rte_service_probe_capability(uint32_t id, uint32_t capability); 100 101 /** 102 * Map or unmap a lcore to a service. 103 * 104 * Each core can be added or removed from running a specific service. This 105 * function enables or disables *lcore* to run *service_id*. 106 * 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. 112 * 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. 116 * 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 120 * 121 * @retval 0 lcore map updated successfully 122 * @retval -EINVAL An invalid service or lcore was provided. 123 */ 124 int32_t rte_service_map_lcore_set(uint32_t service_id, uint32_t lcore, 125 uint32_t enable); 126 127 /** 128 * Retrieve the mapping of an lcore to a service. 129 * 130 * @param service_id the service to apply the lcore to 131 * @param lcore The lcore that will be mapped to service 132 * 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. 136 */ 137 int32_t rte_service_map_lcore_get(uint32_t service_id, uint32_t lcore); 138 139 /** 140 * Set the runstate of the service. 141 * 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. 144 * 145 * @param id The id of the service 146 * @param runstate The run state to apply to the service 147 * 148 * @retval 0 The service was successfully started 149 * @retval -EINVAL Invalid service id 150 */ 151 int32_t rte_service_runstate_set(uint32_t id, uint32_t runstate); 152 153 /** 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. 161 * 162 * @retval 1 Service is running 163 * @retval 0 Service is stopped 164 * @retval -EINVAL Invalid service id 165 */ 166 int32_t rte_service_runstate_get(uint32_t id); 167 168 /** 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. 173 * 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. 177 * 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 181 */ 182 int32_t 183 rte_service_may_be_active(uint32_t id); 184 185 /** 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*. 189 * 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. 192 * 193 * @retval 0 Success 194 * @retval -EINVAL Invalid service ID 195 */ 196 int32_t rte_service_set_runstate_mapped_check(uint32_t id, int32_t enable); 197 198 /** 199 * This function runs a service callback from a non-service lcore. 200 * 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. 203 * 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. 207 * 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. 215 * 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 221 * 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. 224 * 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 230 */ 231 int32_t rte_service_run_iter_on_app_lcore(uint32_t id, 232 uint32_t serialize_multithread_unsafe); 233 234 /** 235 * Start a service core. 236 * 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. 241 * 242 * @retval 0 Success 243 * @retval -EINVAL Failed to start core. The *lcore_id* passed in is not 244 * currently assigned to be a service core. 245 */ 246 int32_t rte_service_lcore_start(uint32_t lcore_id); 247 248 /** 249 * Stop a service core. 250 * 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. 254 * 255 * The *rte_service_lcore_may_be_active* API can be used to check if the 256 * service lcore is * still active. 257 * 258 * @retval 0 Success 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 264 * lcore. 265 */ 266 int32_t rte_service_lcore_stop(uint32_t lcore_id); 267 268 /** 269 * Reports if a service lcore is currently running. 270 * 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. 276 * 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. 280 */ 281 __rte_experimental 282 int32_t rte_service_lcore_may_be_active(uint32_t lcore_id); 283 284 /** 285 * Adds lcore to the list of service cores. 286 * 287 * This functions can be used at runtime in order to modify the service core 288 * mask. 289 * 290 * @retval 0 Success 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 294 */ 295 int32_t rte_service_lcore_add(uint32_t lcore); 296 297 /** 298 * Removes lcore from the list of service cores. 299 * 300 * This can fail if the core is not stopped, see *rte_service_core_stop*. 301 * 302 * @retval 0 Success 303 * @retval -EBUSY Lcore is not stopped, stop service core before removing. 304 * @retval -EINVAL failed to add lcore to service core mask. 305 */ 306 int32_t rte_service_lcore_del(uint32_t lcore); 307 308 /** 309 * Retrieve the number of service cores currently available. 310 * 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. 314 * 315 * See *rte_service_lcore_list* for details on retrieving the lcore_id of each 316 * service core. 317 * 318 * @return The number of service cores currently configured. 319 */ 320 int32_t rte_service_lcore_count(void); 321 322 /** 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. 326 * 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. 330 * 331 * @retval 0 Success 332 */ 333 int32_t rte_service_lcore_reset_all(void); 334 335 /** 336 * Enable or disable statistics collection for *service*. 337 * 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. 341 * @retval 0 Success 342 * @retval -EINVAL Invalid service pointer passed 343 */ 344 int32_t rte_service_set_stats_enable(uint32_t id, int32_t enable); 345 346 /** 347 * Retrieve the list of currently enabled service cores. 348 * 349 * This function fills in an application supplied array, with each element 350 * indicating the lcore_id of a service core. 351 * 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. 361 */ 362 int32_t rte_service_lcore_list(uint32_t array[], uint32_t n); 363 364 /** 365 * Get the number of services running on the supplied lcore. 366 * 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. 371 */ 372 int32_t rte_service_lcore_count_services(uint32_t lcore); 373 374 /** 375 * Dumps any information available about the service. When id is UINT32_MAX, 376 * this function dumps info for all services. 377 * 378 * @retval 0 Statistics have been successfully dumped 379 * @retval -EINVAL Invalid service id provided 380 */ 381 int32_t rte_service_dump(FILE *f, uint32_t id); 382 383 /** 384 * Returns the number of cycles that this service has consumed 385 */ 386 #define RTE_SERVICE_ATTR_CYCLES 0 387 388 /** 389 * Returns the count of invocations of this service function 390 */ 391 #define RTE_SERVICE_ATTR_CALL_COUNT 1 392 393 /** 394 * Get an attribute from a service. 395 * 396 * @retval 0 Success, the attribute value has been written to *attr_value*. 397 * -EINVAL Invalid id, attr_id or attr_value was NULL. 398 */ 399 int32_t rte_service_attr_get(uint32_t id, uint32_t attr_id, 400 uint64_t *attr_value); 401 402 /** 403 * Reset all attribute values of a service. 404 * 405 * @param id The service to reset all statistics of 406 * @retval 0 Successfully reset attributes 407 * -EINVAL Invalid service id provided 408 */ 409 int32_t rte_service_attr_reset_all(uint32_t id); 410 411 /** 412 * Returns the number of times the service runner has looped. 413 */ 414 #define RTE_SERVICE_LCORE_ATTR_LOOPS 0 415 416 /** 417 * Get an attribute from a service core. 418 * 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. 425 */ 426 int32_t 427 rte_service_lcore_attr_get(uint32_t lcore, uint32_t attr_id, 428 uint64_t *attr_value); 429 430 /** 431 * Reset all attribute values of a service core. 432 * 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. 437 */ 438 int32_t 439 rte_service_lcore_attr_reset_all(uint32_t lcore); 440 441 #ifdef __cplusplus 442 } 443 #endif 444 445 446 #endif /* _RTE_SERVICE_H_ */ 447