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 #include<stdio.h> 27 #include <stdint.h> 28 29 #include <rte_config.h> 30 #include <rte_lcore.h> 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 #define RTE_SERVICE_NAME_MAX 32 37 38 /* Capabilities of a service. 39 * 40 * Use the rte_service_probe_capability() function to check if a service is 41 * capable of a specific capability. 42 */ 43 /** When set, the service is capable of having multiple threads run it at the 44 * same time. 45 */ 46 #define RTE_SERVICE_CAP_MT_SAFE (1 << 0) 47 48 /** 49 * Return the number of services registered. 50 * 51 * @return The number of services registered. 52 */ 53 uint32_t rte_service_get_count(void); 54 55 /** 56 * Return the id of a service by name. 57 * 58 * This function provides the id of the service using the service name as 59 * lookup key. The service id is to be passed to other functions in the 60 * rte_service_* API. 61 * 62 * Example usage: 63 * @code 64 * uint32_t service_id; 65 * int32_t ret = rte_service_get_by_name("service_X", &service_id); 66 * if (ret) { 67 * // handle error 68 * } 69 * @endcode 70 * 71 * @param name The name of the service to retrieve 72 * @param[out] service_id A pointer to a uint32_t, to be filled in with the id. 73 * @retval 0 Success. The service id is provided in *service_id*. 74 * @retval -EINVAL Null *service_id* pointer provided 75 * @retval -ENODEV No such service registered 76 */ 77 int32_t rte_service_get_by_name(const char *name, uint32_t *service_id); 78 79 /** 80 * Return the name of the service. 81 * 82 * @return A pointer to the name of the service. The returned pointer remains 83 * in ownership of the service, and the application must not free it. 84 */ 85 const char *rte_service_get_name(uint32_t id); 86 87 /** 88 * Check if a service has a specific capability. 89 * 90 * This function returns if *service* has implements *capability*. 91 * See RTE_SERVICE_CAP_* defines for a list of valid capabilities. 92 * @retval 1 Capability supported by this service instance 93 * @retval 0 Capability not supported by this service instance 94 */ 95 int32_t rte_service_probe_capability(uint32_t id, uint32_t capability); 96 97 /** 98 * Map or unmap a lcore to a service. 99 * 100 * Each core can be added or removed from running a specific service. This 101 * function enables or disables *lcore* to run *service_id*. 102 * 103 * If multiple cores are enabled on a service, a lock is used to ensure that 104 * only one core runs the service at a time. The exception to this is when 105 * a service indicates that it is multi-thread safe by setting the capability 106 * called RTE_SERVICE_CAP_MT_SAFE. With the multi-thread safe capability set, 107 * the service function can be run on multiple threads at the same time. 108 * 109 * If the service is known to be mapped to a single lcore, setting the 110 * capability of the service to RTE_SERVICE_CAP_MT_SAFE can achieve 111 * better performance by avoiding the use of lock. 112 * 113 * @param service_id the service to apply the lcore to 114 * @param lcore The lcore that will be mapped to service 115 * @param enable Zero to unmap or disable the core, non-zero to enable 116 * 117 * @retval 0 lcore map updated successfully 118 * @retval -EINVAL An invalid service or lcore was provided. 119 */ 120 int32_t rte_service_map_lcore_set(uint32_t service_id, uint32_t lcore, 121 uint32_t enable); 122 123 /** 124 * Retrieve the mapping of an lcore to a service. 125 * 126 * @param service_id the service to apply the lcore to 127 * @param lcore The lcore that will be mapped to service 128 * 129 * @retval 1 lcore is mapped to service 130 * @retval 0 lcore is not mapped to service 131 * @retval -EINVAL An invalid service or lcore was provided. 132 */ 133 int32_t rte_service_map_lcore_get(uint32_t service_id, uint32_t lcore); 134 135 /** 136 * Set the runstate of the service. 137 * 138 * Each service is either running or stopped. Setting a non-zero runstate 139 * enables the service to run, while setting runstate zero disables it. 140 * 141 * @param id The id of the service 142 * @param runstate The run state to apply to the service 143 * 144 * @retval 0 The service was successfully started 145 * @retval -EINVAL Invalid service id 146 */ 147 int32_t rte_service_runstate_set(uint32_t id, uint32_t runstate); 148 149 /** 150 * Get the runstate for the service with *id*. See rte_service_runstate_set() 151 * for details of runstates. A service can call this function to ensure that 152 * the application has indicated that it will receive CPU cycles. Either a 153 * service-core is mapped (default case), or the application has explicitly 154 * disabled the check that a service-cores is mapped to the service and takes 155 * responsibility to run the service manually using the available function 156 * rte_service_run_iter_on_app_lcore() to do so. 157 * 158 * @retval 1 Service is running 159 * @retval 0 Service is stopped 160 * @retval -EINVAL Invalid service id 161 */ 162 int32_t rte_service_runstate_get(uint32_t id); 163 164 /** 165 * This function returns whether the service may be currently executing on 166 * at least one lcore, or definitely is not. This function can be used to 167 * determine if, after setting the service runstate to stopped, the service 168 * is still executing a service lcore. 169 * 170 * Care must be taken if calling this function when the service runstate is 171 * running, since the result of this function may be incorrect by the time the 172 * function returns due to service cores running in parallel. 173 * 174 * @retval 1 Service may be running on one or more lcores 175 * @retval 0 Service is not running on any lcore 176 * @retval -EINVAL Invalid service id 177 */ 178 int32_t 179 rte_service_may_be_active(uint32_t id); 180 181 /** 182 * Enable or disable the check for a service-core being mapped to the service. 183 * An application can disable the check when takes the responsibility to run a 184 * service itself using rte_service_run_iter_on_app_lcore(). 185 * 186 * @param id The id of the service to set the check on 187 * @param enable When zero, the check is disabled. Non-zero enables the check. 188 * 189 * @retval 0 Success 190 * @retval -EINVAL Invalid service ID 191 */ 192 int32_t rte_service_set_runstate_mapped_check(uint32_t id, int32_t enable); 193 194 /** 195 * This function runs a service callback from a non-service lcore. 196 * 197 * This function is designed to enable gradual porting to service cores, and 198 * to enable unit tests to verify a service behaves as expected. 199 * 200 * When called, this function ensures that the service identified by *id* is 201 * safe to run on this lcore. Multi-thread safe services are invoked even if 202 * other cores are simultaneously running them as they are multi-thread safe. 203 * 204 * Multi-thread unsafe services are handled depending on the variable 205 * *serialize_multithread_unsafe*: 206 * - When set, the function will check if a service is already being invoked 207 * on another lcore, refusing to run it and returning -EBUSY. 208 * - When zero, the application takes responsibility to ensure that the service 209 * indicated by *id* is not going to be invoked by another lcore. This setting 210 * avoids atomic operations, so is likely to be more performant. 211 * 212 * @param id The ID of the service to run 213 * @param serialize_multithread_unsafe This parameter indicates to the service 214 * cores library if it is required to use atomics to serialize access 215 * to mult-thread unsafe services. As there is an overhead in using 216 * atomics, applications can choose to enable or disable this feature 217 * 218 * Note that any thread calling this function MUST be a DPDK EAL thread, as 219 * the rte_lcore_id() function is used to access internal data structures. 220 * 221 * @retval 0 Service was run on the calling thread successfully 222 * @retval -EBUSY Another lcore is executing the service, and it is not a 223 * multi-thread safe service, so the service was not run on this lcore 224 * @retval -ENOEXEC Service is not in a run-able state 225 * @retval -EINVAL Invalid service id 226 */ 227 int32_t rte_service_run_iter_on_app_lcore(uint32_t id, 228 uint32_t serialize_multithread_unsafe); 229 230 /** 231 * Start a service core. 232 * 233 * Starting a core makes the core begin polling. Any services assigned to it 234 * will be run as fast as possible. The application must ensure that the lcore 235 * is in a launchable state: e.g. call rte_eal_lcore_wait() on the lcore_id 236 * before calling this function. 237 * 238 * @retval 0 Success 239 * @retval -EINVAL Failed to start core. The *lcore_id* passed in is not 240 * currently assigned to be a service core. 241 */ 242 int32_t rte_service_lcore_start(uint32_t lcore_id); 243 244 /** 245 * Stop a service core. 246 * 247 * Stopping a core makes the core become idle, but remains assigned as a 248 * service core. Note that the service lcore thread may not have returned from 249 * the service it is running when this API returns. 250 * 251 * The rte_service_lcore_may_be_active() API can be used to check if the 252 * service lcore is * still active. 253 * 254 * @retval 0 Success 255 * @retval -EINVAL Invalid *lcore_id* provided 256 * @retval -EALREADY Already stopped core 257 * @retval -EBUSY Failed to stop core, as it would cause a service to not 258 * be run, as this is the only core currently running the service. 259 * The application must stop the service first, and then stop the 260 * lcore. 261 */ 262 int32_t rte_service_lcore_stop(uint32_t lcore_id); 263 264 /** 265 * Reports if a service lcore is currently running. 266 * 267 * This function returns if the core has finished service cores code, and has 268 * returned to EAL control. If rte_service_lcore_stop() has been called but 269 * the lcore has not returned to EAL yet, it might be required to wait and call 270 * this function again. The amount of time to wait before the core returns 271 * depends on the duration of the services being run. 272 * 273 * @retval 0 Service thread is not active, and lcore has been returned to EAL. 274 * @retval 1 Service thread is in the service core polling loop. 275 * @retval -EINVAL Invalid *lcore_id* provided. 276 */ 277 int32_t rte_service_lcore_may_be_active(uint32_t lcore_id); 278 279 /** 280 * Adds lcore to the list of service cores. 281 * 282 * This functions can be used at runtime in order to modify the service core 283 * mask. 284 * 285 * @retval 0 Success 286 * @retval -EBUSY lcore is busy, and not available for service core duty 287 * @retval -EALREADY lcore is already added to the service core list 288 * @retval -EINVAL Invalid lcore provided 289 */ 290 int32_t rte_service_lcore_add(uint32_t lcore); 291 292 /** 293 * Removes lcore from the list of service cores. 294 * 295 * This can fail if the core is not stopped, see rte_service_core_stop(). 296 * 297 * @retval 0 Success 298 * @retval -EBUSY Lcore is not stopped, stop service core before removing. 299 * @retval -EINVAL failed to add lcore to service core mask. 300 */ 301 int32_t rte_service_lcore_del(uint32_t lcore); 302 303 /** 304 * Retrieve the number of service cores currently available. 305 * 306 * This function returns the integer count of service cores available. The 307 * service core count can be used in mapping logic when creating mappings 308 * from service cores to services. 309 * 310 * See rte_service_lcore_list() for details on retrieving the lcore_id of each 311 * service core. 312 * 313 * @return The number of service cores currently configured. 314 */ 315 int32_t rte_service_lcore_count(void); 316 317 /** 318 * Resets all service core mappings. This does not remove the service cores 319 * from duty, just unmaps all services / cores, and stops() the service cores. 320 * The runstate of services is not modified. 321 * 322 * The cores that are stopped with this call, are in WAIT state. 323 * 324 * @retval 0 Success 325 */ 326 int32_t rte_service_lcore_reset_all(void); 327 328 /** 329 * Enable or disable statistics collection for *service*. 330 * 331 * This function enables per core, per-service cycle count collection. 332 * @param id The service to enable statistics gathering on. 333 * @param enable Zero to disable statistics, non-zero to enable. 334 * @retval 0 Success 335 * @retval -EINVAL Invalid service pointer passed 336 */ 337 int32_t rte_service_set_stats_enable(uint32_t id, int32_t enable); 338 339 /** 340 * Retrieve the list of currently enabled service cores. 341 * 342 * This function fills in an application supplied array, with each element 343 * indicating the lcore_id of a service core. 344 * 345 * Adding and removing service cores can be performed using 346 * rte_service_lcore_add() and rte_service_lcore_del(). 347 * @param [out] array An array of at least rte_service_lcore_count() items. 348 * If statically allocating the buffer, use RTE_MAX_LCORE. 349 * @param [out] n The size of *array*. 350 * @retval >=0 Number of service cores that have been populated in the array 351 * @retval -ENOMEM The provided array is not large enough to fill in the 352 * service core list. No items have been populated, call this function 353 * with a size of at least rte_service_core_count() items. 354 */ 355 int32_t rte_service_lcore_list(uint32_t array[], uint32_t n); 356 357 /** 358 * Get the number of services running on the supplied lcore. 359 * 360 * @param lcore Id of the service core. 361 * @retval >=0 Number of services registered to this core. 362 * @retval -EINVAL Invalid lcore provided 363 * @retval -ENOTSUP The provided lcore is not a service core. 364 */ 365 int32_t rte_service_lcore_count_services(uint32_t lcore); 366 367 /** 368 * Dumps any information available about the service. When id is UINT32_MAX, 369 * this function dumps info for all services. 370 * 371 * @retval 0 Statistics have been successfully dumped 372 * @retval -EINVAL Invalid service id provided 373 */ 374 int32_t rte_service_dump(FILE *f, uint32_t id); 375 376 /** 377 * Returns the number of cycles that this service has consumed. Only 378 * cycles spent in non-idle calls (i.e., calls not returning -EAGAIN) 379 * count. 380 */ 381 #define RTE_SERVICE_ATTR_CYCLES 0 382 383 /** 384 * Returns the total number of invocations of this service function 385 * (regardless of return value). 386 */ 387 #define RTE_SERVICE_ATTR_CALL_COUNT 1 388 389 /** 390 * Returns the number of invocations of this service function where the 391 * service reported having not performed any useful work (i.e., 392 * returned -EAGAIN). 393 */ 394 #define RTE_SERVICE_ATTR_IDLE_CALL_COUNT 2 395 396 /** 397 * Returns the number of invocations of this service function where the 398 * service reported an error (i.e., the return value was neither 0 nor 399 * -EAGAIN). 400 */ 401 #define RTE_SERVICE_ATTR_ERROR_CALL_COUNT 3 402 403 /** 404 * Get an attribute from a service. 405 * 406 * @retval 0 Success, the attribute value has been written to *attr_value*. 407 * -EINVAL Invalid id, attr_id or attr_value was NULL. 408 */ 409 int32_t rte_service_attr_get(uint32_t id, uint32_t attr_id, 410 uint64_t *attr_value); 411 412 /** 413 * Reset all attribute values of a service. 414 * 415 * @param id The service to reset all statistics of 416 * @retval 0 Successfully reset attributes 417 * -EINVAL Invalid service id provided 418 */ 419 int32_t rte_service_attr_reset_all(uint32_t id); 420 421 /** 422 * Returns the number of times the service runner has looped. 423 */ 424 #define RTE_SERVICE_LCORE_ATTR_LOOPS 0 425 426 /** 427 * Returns the total number of cycles that the lcore has spent on 428 * running services. Only non-idle calls (i.e., calls not returning 429 * -EAGAIN) count toward this total. 430 */ 431 #define RTE_SERVICE_LCORE_ATTR_CYCLES 1 432 433 /** 434 * Get an attribute from a service core. 435 * 436 * @param lcore Id of the service core. 437 * @param attr_id Id of the attribute to be retrieved. 438 * @param [out] attr_value Pointer to storage in which to write retrieved value. 439 * @retval 0 Success, the attribute value has been written to *attr_value*. 440 * -EINVAL Invalid lcore, attr_id or attr_value was NULL. 441 * -ENOTSUP lcore is not a service core. 442 */ 443 int32_t 444 rte_service_lcore_attr_get(uint32_t lcore, uint32_t attr_id, 445 uint64_t *attr_value); 446 447 /** 448 * Reset all attribute values of a service core. 449 * 450 * @param lcore The service core to reset all the statistics of 451 * @retval 0 Successfully reset attributes 452 * -EINVAL Invalid service id provided 453 * -ENOTSUP lcore is not a service core. 454 */ 455 int32_t 456 rte_service_lcore_attr_reset_all(uint32_t lcore); 457 458 #ifdef __cplusplus 459 } 460 #endif 461 462 463 #endif /* _RTE_SERVICE_H_ */ 464