ceph/src/spdk/dpdk/lib/librte_eal/include/rte_service.h

   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.
 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  * Adds lcore to the list of service cores.
 266  *
 267  * This functions can be used at runtime in order to modify the service core
 268  * mask.
 269  *
 270  * @retval 0 Success
 271  * @retval -EBUSY lcore is busy, and not available for service core duty
 272  * @retval -EALREADY lcore is already added to the service core list
 273  * @retval -EINVAL Invalid lcore provided
 274  */
 275 int32_t rte_service_lcore_add(uint32_t lcore);
 276
 277 /**
 278  * Removes lcore from the list of service cores.
 279  *
 280  * This can fail if the core is not stopped, see *rte_service_core_stop*.
 281  *
 282  * @retval 0 Success
 283  * @retval -EBUSY Lcore is not stopped, stop service core before removing.
 284  * @retval -EINVAL failed to add lcore to service core mask.
 285  */
 286 int32_t rte_service_lcore_del(uint32_t lcore);
 287
 288 /**
 289  * Retrieve the number of service cores currently available.
 290  *
 291  * This function returns the integer count of service cores available. The
 292  * service core count can be used in mapping logic when creating mappings
 293  * from service cores to services.
 294  *
 295  * See *rte_service_lcore_list* for details on retrieving the lcore_id of each
 296  * service core.
 297  *
 298  * @return The number of service cores currently configured.
 299  */
 300 int32_t rte_service_lcore_count(void);
 301
 302 /**
 303  * Resets all service core mappings. This does not remove the service cores
 304  * from duty, just unmaps all services / cores, and stops() the service cores.
 305  * The runstate of services is not modified.
 306  *
 307  * @retval 0 Success
 308  */
 309 int32_t rte_service_lcore_reset_all(void);
 310
 311 /**
 312  * Enable or disable statistics collection for *service*.
 313  *
 314  * This function enables per core, per-service cycle count collection.
 315  * @param id The service to enable statistics gathering on.
 316  * @param enable Zero to disable statistics, non-zero to enable.
 317  * @retval 0 Success
 318  * @retval -EINVAL Invalid service pointer passed
 319  */
 320 int32_t rte_service_set_stats_enable(uint32_t id, int32_t enable);
 321
 322 /**
 323  * Retrieve the list of currently enabled service cores.
 324  *
 325  * This function fills in an application supplied array, with each element
 326  * indicating the lcore_id of a service core.
 327  *
 328  * Adding and removing service cores can be performed using
 329  * *rte_service_lcore_add* and *rte_service_lcore_del*.
 330  * @param [out] array An array of at least *rte_service_lcore_count* items.
 331  *              If statically allocating the buffer, use RTE_MAX_LCORE.
 332  * @param [out] n The size of *array*.
 333  * @retval >=0 Number of service cores that have been populated in the array
 334  * @retval -ENOMEM The provided array is not large enough to fill in the
 335  *          service core list. No items have been populated, call this function
 336  *          with a size of at least *rte_service_core_count* items.
 337  */
 338 int32_t rte_service_lcore_list(uint32_t array[], uint32_t n);
 339
 340 /**
 341  * Get the number of services running on the supplied lcore.
 342  *
 343  * @param lcore Id of the service core.
 344  * @retval >=0 Number of services registered to this core.
 345  * @retval -EINVAL Invalid lcore provided
 346  * @retval -ENOTSUP The provided lcore is not a service core.
 347  */
 348 int32_t rte_service_lcore_count_services(uint32_t lcore);
 349
 350 /**
 351  * Dumps any information available about the service. When id is UINT32_MAX,
 352  * this function dumps info for all services.
 353  *
 354  * @retval 0 Statistics have been successfully dumped
 355  * @retval -EINVAL Invalid service id provided
 356  */
 357 int32_t rte_service_dump(FILE *f, uint32_t id);
 358
 359 /**
 360  * Returns the number of cycles that this service has consumed
 361  */
 362 #define RTE_SERVICE_ATTR_CYCLES 0
 363
 364 /**
 365  * Returns the count of invocations of this service function
 366  */
 367 #define RTE_SERVICE_ATTR_CALL_COUNT 1
 368
 369 /**
 370  * Get an attribute from a service.
 371  *
 372  * @retval 0 Success, the attribute value has been written to *attr_value*.
 373  *         -EINVAL Invalid id, attr_id or attr_value was NULL.
 374  */
 375 int32_t rte_service_attr_get(uint32_t id, uint32_t attr_id,
 376                 uint64_t *attr_value);
 377
 378 /**
 379  * Reset all attribute values of a service.
 380  *
 381  * @param id The service to reset all statistics of
 382  * @retval 0 Successfully reset attributes
 383  *         -EINVAL Invalid service id provided
 384  */
 385 int32_t rte_service_attr_reset_all(uint32_t id);
 386
 387 /**
 388  * Returns the number of times the service runner has looped.
 389  */
 390 #define RTE_SERVICE_LCORE_ATTR_LOOPS 0
 391
 392 /**
 393  * Get an attribute from a service core.
 394  *
 395  * @param lcore Id of the service core.
 396  * @param attr_id Id of the attribute to be retrieved.
 397  * @param [out] attr_value Pointer to storage in which to write retrieved value.
 398  * @retval 0 Success, the attribute value has been written to *attr_value*.
 399  *         -EINVAL Invalid lcore, attr_id or attr_value was NULL.
 400  *         -ENOTSUP lcore is not a service core.
 401  */
 402 int32_t
 403 rte_service_lcore_attr_get(uint32_t lcore, uint32_t attr_id,
 404                            uint64_t *attr_value);
 405
 406 /**
 407  * Reset all attribute values of a service core.
 408  *
 409  * @param lcore The service core to reset all the statistics of
 410  * @retval 0 Successfully reset attributes
 411  *         -EINVAL Invalid service id provided
 412  *         -ENOTSUP lcore is not a service core.
 413  */
 414 int32_t
 415 rte_service_lcore_attr_reset_all(uint32_t lcore);
 416
 417 #ifdef __cplusplus
 418 }
 419 #endif
 420
 421
 422 #endif /* _RTE_SERVICE_H_ */