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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 | /* * Copyright (c) 2016 Wind River Systems, Inc. * * SPDX-License-Identifier: Apache-2.0 */ /** * @brief Mailboxes. */ #include <kernel.h> #include <kernel_structs.h> #include <debug/object_tracing_common.h> #include <toolchain.h> #include <linker/sections.h> #include <string.h> #include <ksched.h> #include <wait_q.h> #include <sys/dlist.h> #include <init.h> #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) /* asynchronous message descriptor type */ struct k_mbox_async { struct _thread_base thread; /* dummy thread object */ struct k_mbox_msg tx_msg; /* transmit message descriptor */ }; /* stack of unused asynchronous message descriptors */ K_STACK_DEFINE(async_msg_free, CONFIG_NUM_MBOX_ASYNC_MSGS); /* allocate an asynchronous message descriptor */ static inline void mbox_async_alloc(struct k_mbox_async **async) { (void)k_stack_pop(&async_msg_free, (stack_data_t *)async, K_FOREVER); } /* free an asynchronous message descriptor */ static inline void mbox_async_free(struct k_mbox_async *async) { k_stack_push(&async_msg_free, (stack_data_t)async); } #endif /* CONFIG_NUM_MBOX_ASYNC_MSGS > 0 */ #ifdef CONFIG_OBJECT_TRACING struct k_mbox *_trace_list_k_mbox; #endif /* CONFIG_OBJECT_TRACING */ #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) || \ defined(CONFIG_OBJECT_TRACING) /* * Do run-time initialization of mailbox object subsystem. */ static int init_mbox_module(struct device *dev) { ARG_UNUSED(dev); /* array of asynchronous message descriptors */ static struct k_mbox_async __noinit async_msg[CONFIG_NUM_MBOX_ASYNC_MSGS]; #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) /* * Create pool of asynchronous message descriptors. * * A dummy thread requires minimal initialization, since it never gets * to execute. The _THREAD_DUMMY flag is sufficient to distinguish a * dummy thread from a real one. The threads are *not* added to the * kernel's list of known threads. * * Once initialized, the address of each descriptor is added to a stack * that governs access to them. */ int i; for (i = 0; i < CONFIG_NUM_MBOX_ASYNC_MSGS; i++) { z_init_thread_base(&async_msg[i].thread, 0, _THREAD_DUMMY, 0); k_stack_push(&async_msg_free, (stack_data_t)&async_msg[i]); } #endif /* CONFIG_NUM_MBOX_ASYNC_MSGS > 0 */ /* Complete initialization of statically defined mailboxes. */ #ifdef CONFIG_OBJECT_TRACING Z_STRUCT_SECTION_FOREACH(k_mbox, mbox) { SYS_TRACING_OBJ_INIT(k_mbox, mbox); } #endif /* CONFIG_OBJECT_TRACING */ return 0; } SYS_INIT(init_mbox_module, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_OBJECTS); #endif /* CONFIG_NUM_MBOX_ASYNC_MSGS or CONFIG_OBJECT_TRACING */ void k_mbox_init(struct k_mbox *mbox_ptr) { z_waitq_init(&mbox_ptr->tx_msg_queue); z_waitq_init(&mbox_ptr->rx_msg_queue); mbox_ptr->lock = (struct k_spinlock) {}; SYS_TRACING_OBJ_INIT(k_mbox, mbox_ptr); } /** * @brief Check compatibility of sender's and receiver's message descriptors. * * Compares sender's and receiver's message descriptors to see if they are * compatible. If so, the descriptor fields are updated to reflect that a * match has occurred. * * @param tx_msg Pointer to transmit message descriptor. * @param rx_msg Pointer to receive message descriptor. * * @return 0 if successfully matched, otherwise -1. */ static int mbox_message_match(struct k_mbox_msg *tx_msg, struct k_mbox_msg *rx_msg) { u32_t temp_info; if (((tx_msg->tx_target_thread == (k_tid_t)K_ANY) || (tx_msg->tx_target_thread == rx_msg->tx_target_thread)) && ((rx_msg->rx_source_thread == (k_tid_t)K_ANY) || (rx_msg->rx_source_thread == tx_msg->rx_source_thread))) { /* update thread identifier fields for both descriptors */ rx_msg->rx_source_thread = tx_msg->rx_source_thread; tx_msg->tx_target_thread = rx_msg->tx_target_thread; /* update application info fields for both descriptors */ temp_info = rx_msg->info; rx_msg->info = tx_msg->info; tx_msg->info = temp_info; /* update data size field for receiver only */ if (rx_msg->size > tx_msg->size) { rx_msg->size = tx_msg->size; } /* update data location fields for receiver only */ rx_msg->tx_data = tx_msg->tx_data; rx_msg->tx_block = tx_msg->tx_block; if (rx_msg->tx_data != NULL) { rx_msg->tx_block.data = NULL; } else if (rx_msg->tx_block.data != NULL) { rx_msg->tx_data = rx_msg->tx_block.data; } else { /* no data */ } /* update syncing thread field for receiver only */ rx_msg->_syncing_thread = tx_msg->_syncing_thread; return 0; } return -1; } /** * @brief Dispose of received message. * * Releases any memory pool block still associated with the message, * then notifies the sender that message processing is complete. * * @param rx_msg Pointer to receive message descriptor. * * @return N/A */ static void mbox_message_dispose(struct k_mbox_msg *rx_msg) { struct k_thread *sending_thread; struct k_mbox_msg *tx_msg; /* do nothing if message was disposed of when it was received */ if (rx_msg->_syncing_thread == NULL) { return; } /* release sender's memory pool block */ if (rx_msg->tx_block.data != NULL) { k_mem_pool_free(&rx_msg->tx_block); rx_msg->tx_block.data = NULL; } /* recover sender info */ sending_thread = rx_msg->_syncing_thread; rx_msg->_syncing_thread = NULL; tx_msg = (struct k_mbox_msg *)sending_thread->base.swap_data; /* update data size field for sender */ tx_msg->size = rx_msg->size; #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) /* * asynchronous send: free asynchronous message descriptor + * dummy thread pair, then give semaphore (if needed) */ if ((sending_thread->base.thread_state & _THREAD_DUMMY) != 0U) { struct k_sem *async_sem = tx_msg->_async_sem; mbox_async_free((struct k_mbox_async *)sending_thread); if (async_sem != NULL) { k_sem_give(async_sem); } return; } #endif /* synchronous send: wake up sending thread */ arch_thread_return_value_set(sending_thread, 0); z_mark_thread_as_not_pending(sending_thread); z_ready_thread(sending_thread); z_reschedule_unlocked(); } /** * @brief Send a mailbox message. * * Helper routine that handles both synchronous and asynchronous sends. * * @param mbox Pointer to the mailbox object. * @param tx_msg Pointer to transmit message descriptor. * @param timeout Maximum time (milliseconds) to wait for the message to be * received (although not necessarily completely processed). * Use K_NO_WAIT to return immediately, or K_FOREVER to wait as long * as necessary. * * @return 0 if successful, -ENOMSG if failed immediately, -EAGAIN if timed out */ static int mbox_message_put(struct k_mbox *mbox, struct k_mbox_msg *tx_msg, s32_t timeout) { struct k_thread *sending_thread; struct k_thread *receiving_thread; struct k_mbox_msg *rx_msg; k_spinlock_key_t key; /* save sender id so it can be used during message matching */ tx_msg->rx_source_thread = _current; /* finish readying sending thread (actual or dummy) for send */ sending_thread = tx_msg->_syncing_thread; sending_thread->base.swap_data = tx_msg; /* search mailbox's rx queue for a compatible receiver */ key = k_spin_lock(&mbox->lock); _WAIT_Q_FOR_EACH(&mbox->rx_msg_queue, receiving_thread) { rx_msg = (struct k_mbox_msg *)receiving_thread->base.swap_data; if (mbox_message_match(tx_msg, rx_msg) == 0) { /* take receiver out of rx queue */ z_unpend_thread(receiving_thread); /* ready receiver for execution */ arch_thread_return_value_set(receiving_thread, 0); z_ready_thread(receiving_thread); #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) /* * asynchronous send: swap out current thread * if receiver has priority, otherwise let it continue * * note: dummy sending thread sits (unqueued) * until the receiver consumes the message */ if ((sending_thread->base.thread_state & _THREAD_DUMMY) != 0U) { z_reschedule(&mbox->lock, key); return 0; } #endif /* * synchronous send: pend current thread (unqueued) * until the receiver consumes the message */ return z_pend_curr(&mbox->lock, key, NULL, K_FOREVER); } } /* didn't find a matching receiver: don't wait for one */ if (timeout == K_NO_WAIT) { k_spin_unlock(&mbox->lock, key); return -ENOMSG; } #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) /* asynchronous send: dummy thread waits on tx queue for receiver */ if ((sending_thread->base.thread_state & _THREAD_DUMMY) != 0U) { z_pend_thread(sending_thread, &mbox->tx_msg_queue, K_FOREVER); k_spin_unlock(&mbox->lock, key); return 0; } #endif /* synchronous send: sender waits on tx queue for receiver or timeout */ return z_pend_curr(&mbox->lock, key, &mbox->tx_msg_queue, timeout); } int k_mbox_put(struct k_mbox *mbox, struct k_mbox_msg *tx_msg, s32_t timeout) { /* configure things for a synchronous send, then send the message */ tx_msg->_syncing_thread = _current; return mbox_message_put(mbox, tx_msg, timeout); } #if (CONFIG_NUM_MBOX_ASYNC_MSGS > 0) void k_mbox_async_put(struct k_mbox *mbox, struct k_mbox_msg *tx_msg, struct k_sem *sem) { struct k_mbox_async *async; /* * allocate an asynchronous message descriptor, configure both parts, * then send the message asynchronously */ mbox_async_alloc(&async); async->thread.prio = _current->base.prio; async->tx_msg = *tx_msg; async->tx_msg._syncing_thread = (struct k_thread *)&async->thread; async->tx_msg._async_sem = sem; (void)mbox_message_put(mbox, &async->tx_msg, K_FOREVER); } #endif void k_mbox_data_get(struct k_mbox_msg *rx_msg, void *buffer) { /* handle case where data is to be discarded */ if (buffer == NULL) { rx_msg->size = 0; mbox_message_dispose(rx_msg); return; } /* copy message data to buffer, then dispose of message */ if ((rx_msg->tx_data != NULL) && (rx_msg->size > 0)) { (void)memcpy(buffer, rx_msg->tx_data, rx_msg->size); } mbox_message_dispose(rx_msg); } int k_mbox_data_block_get(struct k_mbox_msg *rx_msg, struct k_mem_pool *pool, struct k_mem_block *block, s32_t timeout) { int result; /* handle case where data is to be discarded */ if (pool == NULL) { rx_msg->size = 0; mbox_message_dispose(rx_msg); return 0; } /* handle case where data is already in a memory pool block */ if (rx_msg->tx_block.data != NULL) { /* give ownership of the block to receiver */ *block = rx_msg->tx_block; rx_msg->tx_block.data = NULL; /* now dispose of message */ mbox_message_dispose(rx_msg); return 0; } /* allocate memory pool block (even when message size is 0!) */ result = k_mem_pool_alloc(pool, block, rx_msg->size, timeout); if (result != 0) { return result; } /* retrieve non-block data into new block, then dispose of message */ k_mbox_data_get(rx_msg, block->data); return 0; } /** * @brief Handle immediate consumption of received mailbox message data. * * Checks to see if received message data should be kept for later retrieval, * or if the data should consumed immediately and the message disposed of. * * The data is consumed immediately in either of the following cases: * 1) The receiver requested immediate retrieval by suppling a buffer * to receive the data. * 2) There is no data to be retrieved. (i.e. Data size is 0 bytes.) * * @param rx_msg Pointer to receive message descriptor. * @param buffer Pointer to buffer to receive data. * * @return 0 */ static int mbox_message_data_check(struct k_mbox_msg *rx_msg, void *buffer) { if (buffer != NULL) { /* retrieve data now, then dispose of message */ k_mbox_data_get(rx_msg, buffer); } else if (rx_msg->size == 0) { /* there is no data to get, so just dispose of message */ mbox_message_dispose(rx_msg); } else { /* keep message around for later data retrieval */ } return 0; } int k_mbox_get(struct k_mbox *mbox, struct k_mbox_msg *rx_msg, void *buffer, s32_t timeout) { struct k_thread *sending_thread; struct k_mbox_msg *tx_msg; k_spinlock_key_t key; int result; /* save receiver id so it can be used during message matching */ rx_msg->tx_target_thread = _current; /* search mailbox's tx queue for a compatible sender */ key = k_spin_lock(&mbox->lock); _WAIT_Q_FOR_EACH(&mbox->tx_msg_queue, sending_thread) { tx_msg = (struct k_mbox_msg *)sending_thread->base.swap_data; if (mbox_message_match(tx_msg, rx_msg) == 0) { /* take sender out of mailbox's tx queue */ z_unpend_thread(sending_thread); k_spin_unlock(&mbox->lock, key); /* consume message data immediately, if needed */ return mbox_message_data_check(rx_msg, buffer); } } /* didn't find a matching sender */ if (timeout == K_NO_WAIT) { /* don't wait for a matching sender to appear */ k_spin_unlock(&mbox->lock, key); return -ENOMSG; } /* wait until a matching sender appears or a timeout occurs */ _current->base.swap_data = rx_msg; result = z_pend_curr(&mbox->lock, key, &mbox->rx_msg_queue, timeout); /* consume message data immediately, if needed */ if (result == 0) { result = mbox_message_data_check(rx_msg, buffer); } return result; } |