ceph/src/seastar/dpdk/lib/librte_timer/rte_timer.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #ifndef _RTE_TIMER_H_
   6 #define _RTE_TIMER_H_
   7
   8 /**
   9  * @file
  10  RTE Timer
  11  *
  12  * This library provides a timer service to RTE Data Plane execution
  13  * units that allows the execution of callback functions asynchronously.
  14  *
  15  * - Timers can be periodic or single (one-shot).
  16  * - The timers can be loaded from one core and executed on another. This has
  17  *   to be specified in the call to rte_timer_reset().
  18  * - High precision is possible. NOTE: this depends on the call frequency to
  19  *   rte_timer_manage() that check the timer expiration for the local core.
  20  * - If not used in an application, for improved performance, it can be
  21  *   disabled at compilation time by not calling the rte_timer_manage()
  22  *   to improve performance.
  23  *
  24  * The timer library uses the rte_get_hpet_cycles() function that
  25  * uses the HPET, when available, to provide a reliable time reference. [HPET
  26  * routines are provided by EAL, which falls back to using the chip TSC (time-
  27  * stamp counter) as fallback when HPET is not available]
  28  *
  29  * This library provides an interface to add, delete and restart a
  30  * timer. The API is based on the BSD callout(9) API with a few
  31  * differences.
  32  *
  33  * See the RTE architecture documentation for more information about the
  34  * design of this library.
  35  */
  36
  37 #include <stdio.h>
  38 #include <stdint.h>
  39 #include <stddef.h>
  40 #include <rte_common.h>
  41 #include <rte_config.h>
  42 #include <rte_spinlock.h>
  43
  44 #ifdef __cplusplus
  45 extern "C" {
  46 #endif
  47
  48 #define RTE_TIMER_STOP    0 /**< State: timer is stopped. */
  49 #define RTE_TIMER_PENDING 1 /**< State: timer is scheduled. */
  50 #define RTE_TIMER_RUNNING 2 /**< State: timer function is running. */
  51 #define RTE_TIMER_CONFIG  3 /**< State: timer is being configured. */
  52
  53 #define RTE_TIMER_NO_OWNER -2 /**< Timer has no owner. */
  54
  55 /**
  56  * Timer type: Periodic or single (one-shot).
  57  */
  58 enum rte_timer_type {
  59         SINGLE,
  60         PERIODICAL
  61 };
  62
  63 /**
  64  * Timer status: A union of the state (stopped, pending, running,
  65  * config) and an owner (the id of the lcore that owns the timer).
  66  */
  67 union rte_timer_status {
  68         RTE_STD_C11
  69         struct {
  70                 uint16_t state;  /**< Stop, pending, running, config. */
  71                 int16_t owner;   /**< The lcore that owns the timer. */
  72         };
  73         uint32_t u32;            /**< To atomic-set status + owner. */
  74 };
  75
  76 #ifdef RTE_LIBRTE_TIMER_DEBUG
  77 /**
  78  * A structure that stores the timer statistics (per-lcore).
  79  */
  80 struct rte_timer_debug_stats {
  81         uint64_t reset;   /**< Number of success calls to rte_timer_reset(). */
  82         uint64_t stop;    /**< Number of success calls to rte_timer_stop(). */
  83         uint64_t manage;  /**< Number of calls to rte_timer_manage(). */
  84         uint64_t pending; /**< Number of pending/running timers. */
  85 };
  86 #endif
  87
  88 struct rte_timer;
  89
  90 /**
  91  * Callback function type for timer expiry.
  92  */
  93 typedef void (*rte_timer_cb_t)(struct rte_timer *, void *);
  94
  95 #define MAX_SKIPLIST_DEPTH 10
  96
  97 /**
  98  * A structure describing a timer in RTE.
  99  */
 100 struct rte_timer
 101 {
 102         uint64_t expire;       /**< Time when timer expire. */
 103         struct rte_timer *sl_next[MAX_SKIPLIST_DEPTH];
 104         volatile union rte_timer_status status; /**< Status of timer. */
 105         uint64_t period;       /**< Period of timer (0 if not periodic). */
 106         rte_timer_cb_t f;      /**< Callback function. */
 107         void *arg;             /**< Argument to callback function. */
 108 };
 109
 110
 111 #ifdef __cplusplus
 112 /**
 113  * A C++ static initializer for a timer structure.
 114  */
 115 #define RTE_TIMER_INITIALIZER {             \
 116         0,                                      \
 117         {NULL},                                 \
 118         {{RTE_TIMER_STOP, RTE_TIMER_NO_OWNER}}, \
 119         0,                                      \
 120         NULL,                                   \
 121         NULL,                                   \
 122         }
 123 #else
 124 /**
 125  * A static initializer for a timer structure.
 126  */
 127 #define RTE_TIMER_INITIALIZER {                      \
 128                 .status = {{                         \
 129                         .state = RTE_TIMER_STOP,     \
 130                         .owner = RTE_TIMER_NO_OWNER, \
 131                 }},                                  \
 132         }
 133 #endif
 134
 135 /**
 136  * @warning
 137  * @b EXPERIMENTAL: this API may change without prior notice
 138  *
 139  * Allocate a timer data instance in shared memory to track a set of pending
 140  * timer lists.
 141  *
 142  * @param id_ptr
 143  *   Pointer to variable into which to write the identifier of the allocated
 144  *   timer data instance.
 145  *
 146  * @return
 147  *   - 0: Success
 148  *   - -ENOSPC: maximum number of timer data instances already allocated
 149  */
 150 int __rte_experimental rte_timer_data_alloc(uint32_t *id_ptr);
 151
 152 /**
 153  * @warning
 154  * @b EXPERIMENTAL: this API may change without prior notice
 155  *
 156  * Deallocate a timer data instance.
 157  *
 158  * @param id
 159  *   Identifier of the timer data instance to deallocate.
 160  *
 161  * @return
 162  *   - 0: Success
 163  *   - -EINVAL: invalid timer data instance identifier
 164  */
 165 int __rte_experimental rte_timer_data_dealloc(uint32_t id);
 166
 167 /**
 168  * Initialize the timer library.
 169  *
 170  * Initializes internal variables (list, locks and so on) for the RTE
 171  * timer library.
 172  *
 173  * @return
 174  *   - 0: Success
 175  *   - -EEXIST: Returned in secondary process when primary process has not
 176  *      yet initialized the timer subsystem
 177  *   - -ENOMEM: Unable to allocate memory needed to initialize timer
 178  *      subsystem
 179  */
 180 int rte_timer_subsystem_init(void);
 181 int rte_timer_subsystem_init_v1905(void);
 182 void rte_timer_subsystem_init_v20(void);
 183
 184 /**
 185  * @warning
 186  * @b EXPERIMENTAL: this API may change without prior notice
 187  *
 188  * Free timer subsystem resources.
 189  */
 190 void __rte_experimental rte_timer_subsystem_finalize(void);
 191
 192 /**
 193  * Initialize a timer handle.
 194  *
 195  * The rte_timer_init() function initializes the timer handle *tim*
 196  * for use. No operations can be performed on a timer before it is
 197  * initialized.
 198  *
 199  * @param tim
 200  *   The timer to initialize.
 201  */
 202 void rte_timer_init(struct rte_timer *tim);
 203
 204 /**
 205  * Reset and start the timer associated with the timer handle.
 206  *
 207  * The rte_timer_reset() function resets and starts the timer
 208  * associated with the timer handle *tim*. When the timer expires after
 209  * *ticks* HPET cycles, the function specified by *fct* will be called
 210  * with the argument *arg* on core *tim_lcore*.
 211  *
 212  * If the timer associated with the timer handle is already running
 213  * (in the RUNNING state), the function will fail. The user has to check
 214  * the return value of the function to see if there is a chance that the
 215  * timer is in the RUNNING state.
 216  *
 217  * If the timer is being configured on another core (the CONFIG state),
 218  * it will also fail.
 219  *
 220  * If the timer is pending or stopped, it will be rescheduled with the
 221  * new parameters.
 222  *
 223  * @param tim
 224  *   The timer handle.
 225  * @param ticks
 226  *   The number of cycles (see rte_get_hpet_hz()) before the callback
 227  *   function is called.
 228  * @param type
 229  *   The type can be either:
 230  *   - PERIODICAL: The timer is automatically reloaded after execution
 231  *     (returns to the PENDING state)
 232  *   - SINGLE: The timer is one-shot, that is, the timer goes to a
 233  *     STOPPED state after execution.
 234  * @param tim_lcore
 235  *   The ID of the lcore where the timer callback function has to be
 236  *   executed. If tim_lcore is LCORE_ID_ANY, the timer library will
 237  *   launch it on a different core for each call (round-robin).
 238  * @param fct
 239  *   The callback function of the timer.
 240  * @param arg
 241  *   The user argument of the callback function.
 242  * @return
 243  *   - 0: Success; the timer is scheduled.
 244  *   - (-1): Timer is in the RUNNING or CONFIG state.
 245  */
 246 int rte_timer_reset(struct rte_timer *tim, uint64_t ticks,
 247                     enum rte_timer_type type, unsigned tim_lcore,
 248                     rte_timer_cb_t fct, void *arg);
 249 int rte_timer_reset_v1905(struct rte_timer *tim, uint64_t ticks,
 250                           enum rte_timer_type type, unsigned int tim_lcore,
 251                           rte_timer_cb_t fct, void *arg);
 252 int rte_timer_reset_v20(struct rte_timer *tim, uint64_t ticks,
 253                         enum rte_timer_type type, unsigned int tim_lcore,
 254                         rte_timer_cb_t fct, void *arg);
 255
 256
 257 /**
 258  * Loop until rte_timer_reset() succeeds.
 259  *
 260  * Reset and start the timer associated with the timer handle. Always
 261  * succeed. See rte_timer_reset() for details.
 262  *
 263  * @param tim
 264  *   The timer handle.
 265  * @param ticks
 266  *   The number of cycles (see rte_get_hpet_hz()) before the callback
 267  *   function is called.
 268  * @param type
 269  *   The type can be either:
 270  *   - PERIODICAL: The timer is automatically reloaded after execution
 271  *     (returns to the PENDING state)
 272  *   - SINGLE: The timer is one-shot, that is, the timer goes to a
 273  *     STOPPED state after execution.
 274  * @param tim_lcore
 275  *   The ID of the lcore where the timer callback function has to be
 276  *   executed. If tim_lcore is LCORE_ID_ANY, the timer library will
 277  *   launch it on a different core for each call (round-robin).
 278  * @param fct
 279  *   The callback function of the timer.
 280  * @param arg
 281  *   The user argument of the callback function.
 282  */
 283 void
 284 rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
 285                      enum rte_timer_type type, unsigned tim_lcore,
 286                      rte_timer_cb_t fct, void *arg);
 287
 288 /**
 289  * Stop a timer.
 290  *
 291  * The rte_timer_stop() function stops the timer associated with the
 292  * timer handle *tim*. It may fail if the timer is currently running or
 293  * being configured.
 294  *
 295  * If the timer is pending or stopped (for instance, already expired),
 296  * the function will succeed. The timer handle tim must have been
 297  * initialized using rte_timer_init(), otherwise, undefined behavior
 298  * will occur.
 299  *
 300  * This function can be called safely from a timer callback. If it
 301  * succeeds, the timer is not referenced anymore by the timer library
 302  * and the timer structure can be freed (even in the callback
 303  * function).
 304  *
 305  * @param tim
 306  *   The timer handle.
 307  * @return
 308  *   - 0: Success; the timer is stopped.
 309  *   - (-1): The timer is in the RUNNING or CONFIG state.
 310  */
 311 int rte_timer_stop(struct rte_timer *tim);
 312 int rte_timer_stop_v1905(struct rte_timer *tim);
 313 int rte_timer_stop_v20(struct rte_timer *tim);
 314
 315 /**
 316  * Loop until rte_timer_stop() succeeds.
 317  *
 318  * After a call to this function, the timer identified by *tim* is
 319  * stopped. See rte_timer_stop() for details.
 320  *
 321  * @param tim
 322  *   The timer handle.
 323  */
 324 void rte_timer_stop_sync(struct rte_timer *tim);
 325
 326 /**
 327  * Test if a timer is pending.
 328  *
 329  * The rte_timer_pending() function tests the PENDING status
 330  * of the timer handle *tim*. A PENDING timer is one that has been
 331  * scheduled and whose function has not yet been called.
 332  *
 333  * @param tim
 334  *   The timer handle.
 335  * @return
 336  *   - 0: The timer is not pending.
 337  *   - 1: The timer is pending.
 338  */
 339 int rte_timer_pending(struct rte_timer *tim);
 340
 341 /**
 342  * Manage the timer list and execute callback functions.
 343  *
 344  * This function must be called periodically from EAL lcores
 345  * main_loop(). It browses the list of pending timers and runs all
 346  * timers that are expired.
 347  *
 348  * The precision of the timer depends on the call frequency of this
 349  * function. However, the more often the function is called, the more
 350  * CPU resources it will use.
 351  *
 352  * @return
 353  *   - 0: Success
 354  *   - -EINVAL: timer subsystem not yet initialized
 355  */
 356 int rte_timer_manage(void);
 357 int rte_timer_manage_v1905(void);
 358 void rte_timer_manage_v20(void);
 359
 360 /**
 361  * Dump statistics about timers.
 362  *
 363  * @param f
 364  *   A pointer to a file for output
 365  * @return
 366  *   - 0: Success
 367  *   - -EINVAL: timer subsystem not yet initialized
 368  */
 369 int rte_timer_dump_stats(FILE *f);
 370 int rte_timer_dump_stats_v1905(FILE *f);
 371 void rte_timer_dump_stats_v20(FILE *f);
 372
 373 /**
 374  * @warning
 375  * @b EXPERIMENTAL: this API may change without prior notice
 376  *
 377  * This function is the same as rte_timer_reset(), except that it allows a
 378  * caller to specify the rte_timer_data instance containing the list to which
 379  * the timer should be added.
 380  *
 381  * @see rte_timer_reset()
 382  *
 383  * @param timer_data_id
 384  *   An identifier indicating which instance of timer data should be used for
 385  *   this operation.
 386  * @param tim
 387  *   The timer handle.
 388  * @param ticks
 389  *   The number of cycles (see rte_get_hpet_hz()) before the callback
 390  *   function is called.
 391  * @param type
 392  *   The type can be either:
 393  *   - PERIODICAL: The timer is automatically reloaded after execution
 394  *     (returns to the PENDING state)
 395  *   - SINGLE: The timer is one-shot, that is, the timer goes to a
 396  *     STOPPED state after execution.
 397  * @param tim_lcore
 398  *   The ID of the lcore where the timer callback function has to be
 399  *   executed. If tim_lcore is LCORE_ID_ANY, the timer library will
 400  *   launch it on a different core for each call (round-robin).
 401  * @param fct
 402  *   The callback function of the timer. This parameter can be NULL if (and
 403  *   only if) rte_timer_alt_manage() will be used to manage this timer.
 404  * @param arg
 405  *   The user argument of the callback function.
 406  * @return
 407  *   - 0: Success; the timer is scheduled.
 408  *   - (-1): Timer is in the RUNNING or CONFIG state.
 409  *   - -EINVAL: invalid timer_data_id
 410  */
 411 int __rte_experimental
 412 rte_timer_alt_reset(uint32_t timer_data_id, struct rte_timer *tim,
 413                     uint64_t ticks, enum rte_timer_type type,
 414                     unsigned int tim_lcore, rte_timer_cb_t fct, void *arg);
 415
 416 /**
 417  * @warning
 418  * @b EXPERIMENTAL: this API may change without prior notice
 419  *
 420  * This function is the same as rte_timer_stop(), except that it allows a
 421  * caller to specify the rte_timer_data instance containing the list from which
 422  * this timer should be removed.
 423  *
 424  * @see rte_timer_stop()
 425  *
 426  * @param timer_data_id
 427  *   An identifier indicating which instance of timer data should be used for
 428  *   this operation.
 429  * @param tim
 430  *   The timer handle.
 431  * @return
 432  *   - 0: Success; the timer is stopped.
 433  *   - (-1): The timer is in the RUNNING or CONFIG state.
 434  *   - -EINVAL: invalid timer_data_id
 435  */
 436 int __rte_experimental
 437 rte_timer_alt_stop(uint32_t timer_data_id, struct rte_timer *tim);
 438
 439 /**
 440  * Callback function type for rte_timer_alt_manage().
 441  */
 442 typedef void (*rte_timer_alt_manage_cb_t)(struct rte_timer *tim);
 443
 444 /**
 445  * @warning
 446  * @b EXPERIMENTAL: this API may change without prior notice
 447  *
 448  * Manage a set of timer lists and execute the specified callback function for
 449  * all expired timers. This function is similar to rte_timer_manage(), except
 450  * that it allows a caller to specify the timer_data instance that should
 451  * be operated on, as well as a set of lcore IDs identifying which timer lists
 452  * should be processed.  Callback functions of individual timers are ignored.
 453  *
 454  * @see rte_timer_manage()
 455  *
 456  * @param timer_data_id
 457  *   An identifier indicating which instance of timer data should be used for
 458  *   this operation.
 459  * @param poll_lcores
 460  *   An array of lcore ids identifying the timer lists that should be processed.
 461  *   NULL is allowed - if NULL, the timer list corresponding to the lcore
 462  *   calling this routine is processed (same as rte_timer_manage()).
 463  * @param n_poll_lcores
 464  *   The size of the poll_lcores array. If 'poll_lcores' is NULL, this parameter
 465  *   is ignored.
 466  * @param f
 467  *   The callback function which should be called for all expired timers.
 468  * @return
 469  *   - 0: success
 470  *   - -EINVAL: invalid timer_data_id
 471  */
 472 int __rte_experimental
 473 rte_timer_alt_manage(uint32_t timer_data_id, unsigned int *poll_lcores,
 474                      int n_poll_lcores, rte_timer_alt_manage_cb_t f);
 475
 476 /**
 477  * Callback function type for rte_timer_stop_all().
 478  */
 479 typedef void (*rte_timer_stop_all_cb_t)(struct rte_timer *tim, void *arg);
 480
 481 /**
 482  * @warning
 483  * @b EXPERIMENTAL: this API may change without prior notice
 484  *
 485  * Walk the pending timer lists for the specified lcore IDs, and for each timer
 486  * that is encountered, stop it and call the specified callback function to
 487  * process it further.
 488  *
 489  * @param timer_data_id
 490  *   An identifier indicating which instance of timer data should be used for
 491  *   this operation.
 492  * @param walk_lcores
 493  *   An array of lcore ids identifying the timer lists that should be processed.
 494  * @param nb_walk_lcores
 495  *   The size of the walk_lcores array.
 496  * @param f
 497  *   The callback function which should be called for each timers. Can be NULL.
 498  * @param f_arg
 499  *   An arbitrary argument that will be passed to f, if it is called.
 500  * @return
 501  *   - 0: success
 502  *   - EINVAL: invalid timer_data_id
 503  */
 504 int __rte_experimental
 505 rte_timer_stop_all(uint32_t timer_data_id, unsigned int *walk_lcores,
 506                    int nb_walk_lcores, rte_timer_stop_all_cb_t f, void *f_arg);
 507
 508 /**
 509  * @warning
 510  * @b EXPERIMENTAL: this API may change without prior notice
 511  *
 512  * This function is the same as rte_timer_dump_stats(), except that it allows
 513  * the caller to specify the rte_timer_data instance that should be used.
 514  *
 515  * @see rte_timer_dump_stats()
 516  *
 517  * @param timer_data_id
 518  *   An identifier indicating which instance of timer data should be used for
 519  *   this operation.
 520  * @param f
 521  *   A pointer to a file for output
 522  * @return
 523  *   - 0: success
 524  *   - -EINVAL: invalid timer_data_id
 525  */
 526 int __rte_experimental
 527 rte_timer_alt_dump_stats(uint32_t timer_data_id, FILE *f);
 528
 529 #ifdef __cplusplus
 530 }
 531 #endif
 532
 533 #endif /* _RTE_TIMER_H_ */