Carl van Schaik | 6d7b2ff | 2018-07-06 22:00:55 +1000 | [diff] [blame] | 1 | /* |
| 2 | * drivers/vservices/core_server.c |
| 3 | * |
| 4 | * Copyright (c) 2012-2018 General Dynamics |
| 5 | * Copyright (c) 2014 Open Kernel Labs, Inc. |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * Server side core service application driver |
| 12 | */ |
| 13 | |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/device.h> |
| 16 | #include <linux/mutex.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/list.h> |
| 19 | #include <linux/err.h> |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/ctype.h> |
| 22 | |
| 23 | #include <vservices/types.h> |
| 24 | #include <vservices/transport.h> |
| 25 | #include <vservices/session.h> |
| 26 | #include <vservices/buffer.h> |
| 27 | #include <vservices/service.h> |
| 28 | |
| 29 | #include <vservices/protocol/core/types.h> |
| 30 | #include <vservices/protocol/core/common.h> |
| 31 | #include <vservices/protocol/core/server.h> |
| 32 | |
| 33 | #include "transport.h" |
| 34 | #include "session.h" |
| 35 | #include "compat.h" |
| 36 | |
| 37 | #define VSERVICE_CORE_SERVICE_NAME "core" |
| 38 | |
| 39 | struct core_server { |
| 40 | struct vs_server_core_state state; |
| 41 | struct vs_service_device *service; |
| 42 | |
| 43 | /* |
| 44 | * A list of messages to send, a mutex protecting it, and a |
| 45 | * work item to process the list. |
| 46 | */ |
| 47 | struct list_head message_queue; |
| 48 | struct mutex message_queue_lock; |
| 49 | struct work_struct message_queue_work; |
| 50 | |
| 51 | struct mutex alloc_lock; |
| 52 | |
| 53 | /* The following are all protected by alloc_lock. */ |
| 54 | unsigned long *in_notify_map; |
| 55 | int in_notify_map_bits; |
| 56 | |
| 57 | unsigned long *out_notify_map; |
| 58 | int out_notify_map_bits; |
| 59 | |
| 60 | unsigned in_quota_remaining; |
| 61 | unsigned out_quota_remaining; |
| 62 | }; |
| 63 | |
| 64 | /* |
| 65 | * Used for message deferral when the core service is over quota. |
| 66 | */ |
| 67 | struct pending_message { |
| 68 | vservice_core_message_id_t type; |
| 69 | struct vs_service_device *service; |
| 70 | struct list_head list; |
| 71 | }; |
| 72 | |
| 73 | #define to_core_server(x) container_of(x, struct core_server, state) |
| 74 | #define dev_to_core_server(x) to_core_server(dev_get_drvdata(x)) |
| 75 | |
| 76 | static struct vs_session_device * |
| 77 | vs_core_server_session(struct core_server *server) |
| 78 | { |
| 79 | return vs_service_get_session(server->service); |
| 80 | } |
| 81 | |
| 82 | static struct core_server * |
| 83 | vs_server_session_core_server(struct vs_session_device *session) |
| 84 | { |
| 85 | struct vs_service_device *core_service = session->core_service; |
| 86 | |
| 87 | if (!core_service) |
| 88 | return NULL; |
| 89 | |
| 90 | return dev_to_core_server(&core_service->dev); |
| 91 | } |
| 92 | |
| 93 | static int vs_server_core_send_service_removed(struct core_server *server, |
| 94 | struct vs_service_device *service) |
| 95 | { |
| 96 | return vs_server_core_core_send_service_removed(&server->state, |
| 97 | service->id, GFP_KERNEL); |
| 98 | } |
| 99 | |
| 100 | static bool |
| 101 | cancel_pending_created(struct core_server *server, |
| 102 | struct vs_service_device *service) |
| 103 | { |
| 104 | struct pending_message *msg; |
| 105 | |
| 106 | list_for_each_entry(msg, &server->message_queue, list) { |
| 107 | if (msg->type == VSERVICE_CORE_CORE_MSG_SERVICE_CREATED && |
| 108 | msg->service == service) { |
| 109 | vs_put_service(msg->service); |
| 110 | list_del(&msg->list); |
| 111 | kfree(msg); |
| 112 | |
| 113 | /* there can only be one */ |
| 114 | return true; |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | return false; |
| 119 | } |
| 120 | |
| 121 | static int vs_server_core_queue_service_removed(struct core_server *server, |
| 122 | struct vs_service_device *service) |
| 123 | { |
| 124 | struct pending_message *msg; |
| 125 | |
| 126 | lockdep_assert_held(&service->ready_lock); |
| 127 | |
| 128 | mutex_lock(&server->message_queue_lock); |
| 129 | |
| 130 | /* |
| 131 | * If we haven't sent the notification that the service was created, |
| 132 | * nuke it and do nothing else. |
| 133 | * |
| 134 | * This is not just an optimisation; see below. |
| 135 | */ |
| 136 | if (cancel_pending_created(server, service)) { |
| 137 | mutex_unlock(&server->message_queue_lock); |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * Do nothing if the core state is not connected. We must avoid |
| 143 | * queueing service_removed messages on a reset service. |
| 144 | * |
| 145 | * Note that we cannot take the core server state lock here, because |
| 146 | * we may (or may not) have been called from a core service message |
| 147 | * handler. Thus, we must beware of races with changes to this |
| 148 | * condition: |
| 149 | * |
| 150 | * - It becomes true when the req_connect handler sends an |
| 151 | * ack_connect, *after* it queues service_created for each existing |
| 152 | * service (while holding the service ready lock). The handler sends |
| 153 | * ack_connect with the message queue lock held. |
| 154 | * |
| 155 | * - If we see the service as connected, then the req_connect |
| 156 | * handler has already queued and sent a service_created for this |
| 157 | * service, so it's ok for us to send a service_removed. |
| 158 | * |
| 159 | * - If we see it as disconnected, the req_connect handler hasn't |
| 160 | * taken the message queue lock to send ack_connect yet, and thus |
| 161 | * has not released the service state lock; so if it queued a |
| 162 | * service_created we caught it in the flush above before it was |
| 163 | * sent. |
| 164 | * |
| 165 | * - It becomes false before the reset / disconnect handlers are |
| 166 | * called and those will both flush the message queue afterwards. |
| 167 | * |
| 168 | * - If we see the service as connected, then the reset / disconnect |
| 169 | * handler is going to flush the message. |
| 170 | * |
| 171 | * - If we see it disconnected, the state change has occurred and |
| 172 | * implicitly had the same effect as this message, so doing |
| 173 | * nothing is correct. |
| 174 | * |
| 175 | * Note that ordering in all of the above cases is guaranteed by the |
| 176 | * message queue lock. |
| 177 | */ |
| 178 | if (!VSERVICE_CORE_STATE_IS_CONNECTED(server->state.state.core)) { |
| 179 | mutex_unlock(&server->message_queue_lock); |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | msg = kzalloc(sizeof(*msg), GFP_KERNEL); |
| 184 | if (!msg) { |
| 185 | mutex_unlock(&server->message_queue_lock); |
| 186 | return -ENOMEM; |
| 187 | } |
| 188 | |
| 189 | msg->type = VSERVICE_CORE_CORE_MSG_SERVICE_REMOVED; |
| 190 | /* put by message_queue_work */ |
| 191 | msg->service = vs_get_service(service); |
| 192 | |
| 193 | list_add_tail(&msg->list, &server->message_queue); |
| 194 | |
| 195 | mutex_unlock(&server->message_queue_lock); |
| 196 | queue_work(server->service->work_queue, &server->message_queue_work); |
| 197 | |
| 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | static int vs_server_core_send_service_created(struct core_server *server, |
| 202 | struct vs_service_device *service) |
| 203 | { |
| 204 | struct vs_session_device *session = |
| 205 | vs_service_get_session(server->service); |
| 206 | |
| 207 | struct vs_mbuf *mbuf; |
| 208 | struct vs_string service_name, protocol_name; |
| 209 | size_t service_name_len, protocol_name_len; |
| 210 | |
| 211 | int err; |
| 212 | |
| 213 | mbuf = vs_server_core_core_alloc_service_created(&server->state, |
| 214 | &service_name, &protocol_name, GFP_KERNEL); |
| 215 | |
| 216 | if (IS_ERR(mbuf)) |
| 217 | return PTR_ERR(mbuf); |
| 218 | |
| 219 | vs_dev_debug(VS_DEBUG_SERVER, session, &session->dev, |
| 220 | "Sending service created message for %d (%s:%s)\n", |
| 221 | service->id, service->name, service->protocol); |
| 222 | |
| 223 | service_name_len = strlen(service->name); |
| 224 | protocol_name_len = strlen(service->protocol); |
| 225 | |
| 226 | if (service_name_len > vs_string_max_size(&service_name) || |
| 227 | protocol_name_len > vs_string_max_size(&protocol_name)) { |
| 228 | dev_err(&session->dev, |
| 229 | "Invalid name/protocol for service %d (%s:%s)\n", |
| 230 | service->id, service->name, |
| 231 | service->protocol); |
| 232 | err = -EINVAL; |
| 233 | goto fail; |
| 234 | } |
| 235 | |
| 236 | vs_string_copyin(&service_name, service->name); |
| 237 | vs_string_copyin(&protocol_name, service->protocol); |
| 238 | |
| 239 | err = vs_server_core_core_send_service_created(&server->state, |
| 240 | service->id, service_name, protocol_name, mbuf); |
| 241 | if (err) { |
| 242 | dev_err(&session->dev, |
| 243 | "Fatal error sending service creation message for %d (%s:%s): %d\n", |
| 244 | service->id, service->name, |
| 245 | service->protocol, err); |
| 246 | goto fail; |
| 247 | } |
| 248 | |
| 249 | return 0; |
| 250 | |
| 251 | fail: |
| 252 | vs_server_core_core_free_service_created(&server->state, |
| 253 | &service_name, &protocol_name, mbuf); |
| 254 | |
| 255 | return err; |
| 256 | } |
| 257 | |
| 258 | static int vs_server_core_queue_service_created(struct core_server *server, |
| 259 | struct vs_service_device *service) |
| 260 | { |
| 261 | struct pending_message *msg; |
| 262 | |
| 263 | lockdep_assert_held(&service->ready_lock); |
| 264 | lockdep_assert_held(&server->service->state_mutex); |
| 265 | |
| 266 | mutex_lock(&server->message_queue_lock); |
| 267 | |
| 268 | /* Do nothing if the core state is disconnected. */ |
| 269 | if (!VSERVICE_CORE_STATE_IS_CONNECTED(server->state.state.core)) { |
| 270 | mutex_unlock(&server->message_queue_lock); |
| 271 | return 0; |
| 272 | } |
| 273 | |
| 274 | msg = kzalloc(sizeof(*msg), GFP_KERNEL); |
| 275 | if (!msg) { |
| 276 | mutex_unlock(&server->message_queue_lock); |
| 277 | return -ENOMEM; |
| 278 | } |
| 279 | |
| 280 | msg->type = VSERVICE_CORE_CORE_MSG_SERVICE_CREATED; |
| 281 | /* put by message_queue_work */ |
| 282 | msg->service = vs_get_service(service); |
| 283 | |
| 284 | list_add_tail(&msg->list, &server->message_queue); |
| 285 | |
| 286 | mutex_unlock(&server->message_queue_lock); |
| 287 | queue_work(server->service->work_queue, &server->message_queue_work); |
| 288 | |
| 289 | return 0; |
| 290 | } |
| 291 | |
| 292 | static struct vs_service_device * |
| 293 | __vs_server_core_register_service(struct vs_session_device *session, |
| 294 | vs_service_id_t service_id, struct vs_service_device *owner, |
| 295 | const char *name, const char *protocol, const void *plat_data) |
| 296 | { |
| 297 | if (!session->is_server) |
| 298 | return ERR_PTR(-ENODEV); |
| 299 | |
| 300 | if (!name || strnlen(name, VSERVICE_CORE_SERVICE_NAME_SIZE + 1) > |
| 301 | VSERVICE_CORE_SERVICE_NAME_SIZE || name[0] == '\n') |
| 302 | return ERR_PTR(-EINVAL); |
| 303 | |
| 304 | /* The server core must only be registered as service_id zero */ |
| 305 | if (service_id == 0 && (owner != NULL || |
| 306 | strcmp(name, VSERVICE_CORE_SERVICE_NAME) != 0 || |
| 307 | strcmp(protocol, VSERVICE_CORE_PROTOCOL_NAME) != 0)) |
| 308 | return ERR_PTR(-EINVAL); |
| 309 | |
| 310 | return vs_service_register(session, owner, service_id, protocol, name, |
| 311 | plat_data); |
| 312 | } |
| 313 | |
| 314 | static struct vs_service_device * |
| 315 | vs_server_core_create_service(struct core_server *server, |
| 316 | struct vs_session_device *session, |
| 317 | struct vs_service_device *owner, vs_service_id_t service_id, |
| 318 | const char *name, const char *protocol, const void *plat_data) |
| 319 | { |
| 320 | struct vs_service_device *service; |
| 321 | |
| 322 | service = __vs_server_core_register_service(session, service_id, |
| 323 | owner, name, protocol, plat_data); |
| 324 | if (IS_ERR(service)) |
| 325 | return service; |
| 326 | |
| 327 | if (protocol) { |
| 328 | vs_service_state_lock(server->service); |
| 329 | vs_service_start(service); |
| 330 | if (VSERVICE_CORE_STATE_IS_CONNECTED(server->state.state.core)) |
| 331 | vs_service_enable(service); |
| 332 | vs_service_state_unlock(server->service); |
| 333 | } |
| 334 | |
| 335 | return service; |
| 336 | } |
| 337 | |
| 338 | static int |
| 339 | vs_server_core_send_service_reset_ready(struct core_server *server, |
| 340 | vservice_core_message_id_t type, |
| 341 | struct vs_service_device *service) |
| 342 | { |
| 343 | bool is_reset = (type == VSERVICE_CORE_CORE_MSG_SERVICE_RESET); |
| 344 | struct vs_session_device *session __maybe_unused = |
| 345 | vs_service_get_session(server->service); |
| 346 | int err; |
| 347 | |
| 348 | vs_dev_debug(VS_DEBUG_SERVER, session, &session->dev, |
| 349 | "Sending %s for service %d\n", |
| 350 | is_reset ? "reset" : "ready", service->id); |
| 351 | |
| 352 | if (is_reset) |
| 353 | err = vs_server_core_core_send_service_reset(&server->state, |
| 354 | service->id, GFP_KERNEL); |
| 355 | else |
| 356 | err = vs_server_core_core_send_server_ready(&server->state, |
| 357 | service->id, service->recv_quota, |
| 358 | service->send_quota, |
| 359 | service->notify_recv_offset, |
| 360 | service->notify_recv_bits, |
| 361 | service->notify_send_offset, |
| 362 | service->notify_send_bits, |
| 363 | GFP_KERNEL); |
| 364 | |
| 365 | return err; |
| 366 | } |
| 367 | |
| 368 | static bool |
| 369 | cancel_pending_ready(struct core_server *server, |
| 370 | struct vs_service_device *service) |
| 371 | { |
| 372 | struct pending_message *msg; |
| 373 | |
| 374 | list_for_each_entry(msg, &server->message_queue, list) { |
| 375 | if (msg->type == VSERVICE_CORE_CORE_MSG_SERVER_READY && |
| 376 | msg->service == service) { |
| 377 | vs_put_service(msg->service); |
| 378 | list_del(&msg->list); |
| 379 | kfree(msg); |
| 380 | |
| 381 | /* there can only be one */ |
| 382 | return true; |
| 383 | } |
| 384 | } |
| 385 | |
| 386 | return false; |
| 387 | } |
| 388 | |
| 389 | static int |
| 390 | vs_server_core_queue_service_reset_ready(struct core_server *server, |
| 391 | vservice_core_message_id_t type, |
| 392 | struct vs_service_device *service) |
| 393 | { |
| 394 | bool is_reset = (type == VSERVICE_CORE_CORE_MSG_SERVICE_RESET); |
| 395 | struct pending_message *msg; |
| 396 | |
| 397 | mutex_lock(&server->message_queue_lock); |
| 398 | |
| 399 | /* |
| 400 | * If this is a reset, and there is an outgoing ready in the |
| 401 | * queue, we must cancel it so it can't be sent with invalid |
| 402 | * transport resources, and then return immediately so we |
| 403 | * don't send a redundant reset. |
| 404 | */ |
| 405 | if (is_reset && cancel_pending_ready(server, service)) { |
| 406 | mutex_unlock(&server->message_queue_lock); |
| 407 | return VS_SERVICE_ALREADY_RESET; |
| 408 | } |
| 409 | |
| 410 | msg = kzalloc(sizeof(*msg), GFP_KERNEL); |
| 411 | if (!msg) { |
| 412 | mutex_unlock(&server->message_queue_lock); |
| 413 | return -ENOMEM; |
| 414 | } |
| 415 | |
| 416 | msg->type = type; |
| 417 | /* put by message_queue_work */ |
| 418 | msg->service = vs_get_service(service); |
| 419 | list_add_tail(&msg->list, &server->message_queue); |
| 420 | |
| 421 | mutex_unlock(&server->message_queue_lock); |
| 422 | queue_work(server->service->work_queue, &server->message_queue_work); |
| 423 | |
| 424 | return 0; |
| 425 | } |
| 426 | |
| 427 | static int vs_core_server_tx_ready(struct vs_server_core_state *state) |
| 428 | { |
| 429 | struct core_server *server = to_core_server(state); |
| 430 | struct vs_session_device *session __maybe_unused = |
| 431 | vs_service_get_session(server->service); |
| 432 | |
| 433 | vs_dev_debug(VS_DEBUG_SERVER, session, &session->dev, "tx_ready\n"); |
| 434 | |
| 435 | queue_work(server->service->work_queue, &server->message_queue_work); |
| 436 | |
| 437 | return 0; |
| 438 | } |
| 439 | |
| 440 | static void message_queue_work(struct work_struct *work) |
| 441 | { |
| 442 | struct core_server *server = container_of(work, struct core_server, |
| 443 | message_queue_work); |
| 444 | struct pending_message *msg; |
| 445 | int err; |
| 446 | |
| 447 | vs_service_state_lock(server->service); |
| 448 | |
| 449 | if (!VSERVICE_CORE_STATE_IS_CONNECTED(server->state.state.core)) { |
| 450 | vs_service_state_unlock(server->service); |
| 451 | return; |
| 452 | } |
| 453 | |
| 454 | /* |
| 455 | * If any pending message fails we exit the loop immediately so that |
| 456 | * we preserve the message order. |
| 457 | */ |
| 458 | mutex_lock(&server->message_queue_lock); |
| 459 | while (!list_empty(&server->message_queue)) { |
| 460 | msg = list_first_entry(&server->message_queue, |
| 461 | struct pending_message, list); |
| 462 | |
| 463 | switch (msg->type) { |
| 464 | case VSERVICE_CORE_CORE_MSG_SERVICE_CREATED: |
| 465 | err = vs_server_core_send_service_created(server, |
| 466 | msg->service); |
| 467 | break; |
| 468 | |
| 469 | case VSERVICE_CORE_CORE_MSG_SERVICE_REMOVED: |
| 470 | err = vs_server_core_send_service_removed(server, |
| 471 | msg->service); |
| 472 | break; |
| 473 | |
| 474 | case VSERVICE_CORE_CORE_MSG_SERVICE_RESET: |
| 475 | case VSERVICE_CORE_CORE_MSG_SERVER_READY: |
| 476 | err = vs_server_core_send_service_reset_ready( |
| 477 | server, msg->type, msg->service); |
| 478 | break; |
| 479 | |
| 480 | default: |
| 481 | dev_warn(&server->service->dev, |
| 482 | "Don't know how to handle pending message type %d\n", |
| 483 | msg->type); |
| 484 | err = 0; |
| 485 | break; |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * If we're out of quota we exit and wait for tx_ready to |
| 490 | * queue us again. |
| 491 | */ |
| 492 | if (err == -ENOBUFS) |
| 493 | break; |
| 494 | |
| 495 | /* Any other error is fatal */ |
| 496 | if (err < 0) { |
| 497 | dev_err(&server->service->dev, |
| 498 | "Failed to send pending message type %d: %d - resetting session", |
| 499 | msg->type, err); |
| 500 | vs_service_reset_nosync(server->service); |
| 501 | break; |
| 502 | } |
| 503 | |
| 504 | /* |
| 505 | * The message sent successfully - remove it from the |
| 506 | * queue. The corresponding vs_get_service() was done |
| 507 | * when the pending message was created. |
| 508 | */ |
| 509 | vs_put_service(msg->service); |
| 510 | list_del(&msg->list); |
| 511 | kfree(msg); |
| 512 | } |
| 513 | mutex_unlock(&server->message_queue_lock); |
| 514 | |
| 515 | vs_service_state_unlock(server->service); |
| 516 | |
| 517 | return; |
| 518 | } |
| 519 | |
| 520 | /* |
| 521 | * Core server sysfs interface |
| 522 | */ |
| 523 | static ssize_t server_core_create_service_store(struct device *dev, |
| 524 | struct device_attribute *attr, const char *buf, size_t count) |
| 525 | { |
| 526 | struct vs_service_device *service = to_vs_service_device(dev); |
| 527 | struct vs_session_device *session = to_vs_session_device(dev->parent); |
| 528 | struct core_server *server = dev_to_core_server(&service->dev); |
| 529 | struct vs_service_device *new_service; |
| 530 | char *p; |
| 531 | ssize_t ret = count; |
| 532 | |
| 533 | /* FIXME - Buffer sizes are not defined in generated headers */ |
| 534 | /* discard leading whitespace */ |
| 535 | while (count && isspace(*buf)) { |
| 536 | buf++; |
| 537 | count--; |
| 538 | } |
| 539 | if (!count) { |
| 540 | dev_info(dev, "empty service name"); |
| 541 | return -EINVAL; |
| 542 | } |
| 543 | /* discard trailing whitespace */ |
| 544 | while (count && isspace(buf[count - 1])) |
| 545 | count--; |
| 546 | |
| 547 | if (count > VSERVICE_CORE_SERVICE_NAME_SIZE) { |
| 548 | dev_info(dev, "service name too long (max %d)\n", VSERVICE_CORE_SERVICE_NAME_SIZE); |
| 549 | return -EINVAL; |
| 550 | } |
| 551 | |
| 552 | p = kstrndup(buf, count, GFP_KERNEL); |
| 553 | |
| 554 | /* |
| 555 | * Writing a service name to this file creates a new service. The |
| 556 | * service is created without a protocol. It will appear in sysfs |
| 557 | * but will not be bound to a driver until a valid protocol name |
| 558 | * has been written to the created devices protocol sysfs attribute. |
| 559 | */ |
| 560 | new_service = vs_server_core_create_service(server, session, service, |
| 561 | VS_SERVICE_AUTO_ALLOCATE_ID, p, NULL, NULL); |
| 562 | if (IS_ERR(new_service)) |
| 563 | ret = PTR_ERR(new_service); |
| 564 | |
| 565 | kfree(p); |
| 566 | |
| 567 | return ret; |
| 568 | } |
| 569 | |
| 570 | static ssize_t server_core_reset_service_store(struct device *dev, |
| 571 | struct device_attribute *attr, const char *buf, size_t count) |
| 572 | { |
| 573 | struct vs_service_device *core_service = to_vs_service_device(dev); |
| 574 | struct vs_session_device *session = |
| 575 | vs_service_get_session(core_service); |
| 576 | struct vs_service_device *target; |
| 577 | vs_service_id_t service_id; |
| 578 | unsigned long val; |
| 579 | int err; |
| 580 | |
| 581 | /* |
| 582 | * Writing a valid service_id to this file does a reset of that service |
| 583 | */ |
| 584 | err = kstrtoul(buf, 0, &val); |
| 585 | if (err) |
| 586 | return err; |
| 587 | |
| 588 | service_id = val; |
| 589 | target = vs_session_get_service(session, service_id); |
| 590 | if (!target) |
| 591 | return -EINVAL; |
| 592 | |
| 593 | err = vs_service_reset(target, core_service); |
| 594 | |
| 595 | vs_put_service(target); |
| 596 | return err < 0 ? err : count; |
| 597 | } |
| 598 | |
| 599 | static ssize_t server_core_remove_service_store(struct device *dev, |
| 600 | struct device_attribute *attr, const char *buf, size_t count) |
| 601 | { |
| 602 | struct vs_service_device *service = to_vs_service_device(dev); |
| 603 | struct vs_session_device *session = vs_service_get_session(service); |
| 604 | struct vs_service_device *target; |
| 605 | vs_service_id_t service_id; |
| 606 | unsigned long val; |
| 607 | int err; |
| 608 | |
| 609 | err = kstrtoul(buf, 0, &val); |
| 610 | if (err) |
| 611 | return err; |
| 612 | |
| 613 | service_id = val; |
| 614 | if (service_id == 0) { |
| 615 | /* |
| 616 | * We don't allow removing the core service this way. The |
| 617 | * core service will be removed when the session is removed. |
| 618 | */ |
| 619 | return -EINVAL; |
| 620 | } |
| 621 | |
| 622 | target = vs_session_get_service(session, service_id); |
| 623 | if (!target) |
| 624 | return -EINVAL; |
| 625 | |
| 626 | err = vs_service_delete(target, service); |
| 627 | |
| 628 | vs_put_service(target); |
| 629 | return err < 0 ? err : count; |
| 630 | } |
| 631 | |
| 632 | static DEVICE_ATTR(create_service, S_IWUSR, |
| 633 | NULL, server_core_create_service_store); |
| 634 | static DEVICE_ATTR(reset_service, S_IWUSR, |
| 635 | NULL, server_core_reset_service_store); |
| 636 | static DEVICE_ATTR(remove_service, S_IWUSR, |
| 637 | NULL, server_core_remove_service_store); |
| 638 | |
| 639 | static struct attribute *server_core_dev_attrs[] = { |
| 640 | &dev_attr_create_service.attr, |
| 641 | &dev_attr_reset_service.attr, |
| 642 | &dev_attr_remove_service.attr, |
| 643 | NULL, |
| 644 | }; |
| 645 | |
| 646 | static const struct attribute_group server_core_attr_group = { |
| 647 | .attrs = server_core_dev_attrs, |
| 648 | }; |
| 649 | |
| 650 | static int init_transport_resource_allocation(struct core_server *server) |
| 651 | { |
| 652 | struct vs_session_device *session = vs_core_server_session(server); |
| 653 | struct vs_transport *transport = session->transport; |
| 654 | size_t size; |
| 655 | int err; |
| 656 | |
| 657 | mutex_init(&server->alloc_lock); |
| 658 | mutex_lock(&server->alloc_lock); |
| 659 | |
| 660 | transport->vt->get_quota_limits(transport, &server->out_quota_remaining, |
| 661 | &server->in_quota_remaining); |
| 662 | |
| 663 | transport->vt->get_notify_bits(transport, &server->out_notify_map_bits, |
| 664 | &server->in_notify_map_bits); |
| 665 | |
| 666 | size = BITS_TO_LONGS(server->in_notify_map_bits) * |
| 667 | sizeof(unsigned long); |
| 668 | server->in_notify_map = kzalloc(size, GFP_KERNEL); |
| 669 | if (server->in_notify_map_bits && !server->in_notify_map) { |
| 670 | err = -ENOMEM; |
| 671 | goto fail; |
| 672 | } |
| 673 | |
| 674 | size = BITS_TO_LONGS(server->out_notify_map_bits) * |
| 675 | sizeof(unsigned long); |
| 676 | server->out_notify_map = kzalloc(size, GFP_KERNEL); |
| 677 | if (server->out_notify_map_bits && !server->out_notify_map) { |
| 678 | err = -ENOMEM; |
| 679 | goto fail_free_in_bits; |
| 680 | } |
| 681 | |
| 682 | mutex_unlock(&server->alloc_lock); |
| 683 | |
| 684 | return 0; |
| 685 | |
| 686 | fail_free_in_bits: |
| 687 | kfree(server->in_notify_map); |
| 688 | fail: |
| 689 | mutex_unlock(&server->alloc_lock); |
| 690 | return err; |
| 691 | } |
| 692 | |
| 693 | static int alloc_quota(unsigned minimum, unsigned best, unsigned set, |
| 694 | unsigned *remaining) |
| 695 | { |
| 696 | unsigned quota; |
| 697 | |
| 698 | if (set) { |
| 699 | quota = set; |
| 700 | |
| 701 | if (quota > *remaining) |
| 702 | return -ENOSPC; |
| 703 | } else if (best) { |
| 704 | quota = min(best, *remaining); |
| 705 | } else { |
| 706 | quota = minimum; |
| 707 | } |
| 708 | |
| 709 | if (quota < minimum) |
| 710 | return -ENOSPC; |
| 711 | |
| 712 | *remaining -= quota; |
| 713 | |
| 714 | return min_t(unsigned, quota, INT_MAX); |
| 715 | } |
| 716 | |
| 717 | static int alloc_notify_bits(unsigned notify_count, unsigned long *map, |
| 718 | unsigned nr_bits) |
| 719 | { |
| 720 | unsigned offset; |
| 721 | |
| 722 | if (notify_count) { |
| 723 | offset = bitmap_find_next_zero_area(map, nr_bits, 0, |
| 724 | notify_count, 0); |
| 725 | |
| 726 | if (offset >= nr_bits || offset > (unsigned)INT_MAX) |
| 727 | return -ENOSPC; |
| 728 | |
| 729 | bitmap_set(map, offset, notify_count); |
| 730 | } else { |
| 731 | offset = 0; |
| 732 | } |
| 733 | |
| 734 | return offset; |
| 735 | } |
| 736 | |
| 737 | /* |
| 738 | * alloc_transport_resources - Allocates the quotas and notification bits for |
| 739 | * a service. |
| 740 | * @server: the core service state. |
| 741 | * @service: the service device to allocate resources for. |
| 742 | * |
| 743 | * This function allocates message quotas and notification bits. It is called |
| 744 | * for the core service in alloc(), and for every other service by the server |
| 745 | * bus probe() function. |
| 746 | */ |
| 747 | static int alloc_transport_resources(struct core_server *server, |
| 748 | struct vs_service_device *service) |
| 749 | { |
| 750 | struct vs_session_device *session __maybe_unused = |
| 751 | vs_service_get_session(service); |
| 752 | unsigned in_bit_offset, out_bit_offset; |
| 753 | unsigned in_quota, out_quota; |
| 754 | int ret; |
| 755 | struct vs_service_driver *driver; |
| 756 | |
| 757 | if (WARN_ON(!service->dev.driver)) |
| 758 | return -ENODEV; |
| 759 | |
| 760 | mutex_lock(&server->alloc_lock); |
| 761 | |
| 762 | driver = to_vs_service_driver(service->dev.driver); |
| 763 | |
| 764 | /* Quota allocations */ |
| 765 | ret = alloc_quota(driver->in_quota_min, driver->in_quota_best, |
| 766 | service->in_quota_set, &server->in_quota_remaining); |
| 767 | if (ret < 0) { |
| 768 | dev_err(&service->dev, "cannot allocate in quota\n"); |
| 769 | goto fail_in_quota; |
| 770 | } |
| 771 | in_quota = ret; |
| 772 | |
| 773 | ret = alloc_quota(driver->out_quota_min, driver->out_quota_best, |
| 774 | service->out_quota_set, &server->out_quota_remaining); |
| 775 | if (ret < 0) { |
| 776 | dev_err(&service->dev, "cannot allocate out quota\n"); |
| 777 | goto fail_out_quota; |
| 778 | } |
| 779 | out_quota = ret; |
| 780 | |
| 781 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &session->dev, |
| 782 | "%d: quota in: %u out: %u; remaining in: %u out: %u\n", |
| 783 | service->id, in_quota, out_quota, |
| 784 | server->in_quota_remaining, |
| 785 | server->out_quota_remaining); |
| 786 | |
| 787 | /* Notification bit allocations */ |
| 788 | ret = alloc_notify_bits(service->notify_recv_bits, |
| 789 | server->in_notify_map, server->in_notify_map_bits); |
| 790 | if (ret < 0) { |
| 791 | dev_err(&service->dev, "cannot allocate in notify bits\n"); |
| 792 | goto fail_in_notify; |
| 793 | } |
| 794 | in_bit_offset = ret; |
| 795 | |
| 796 | ret = alloc_notify_bits(service->notify_send_bits, |
| 797 | server->out_notify_map, server->out_notify_map_bits); |
| 798 | if (ret < 0) { |
| 799 | dev_err(&service->dev, "cannot allocate out notify bits\n"); |
| 800 | goto fail_out_notify; |
| 801 | } |
| 802 | out_bit_offset = ret; |
| 803 | |
| 804 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &session->dev, |
| 805 | "notify bits in: %u/%u out: %u/%u\n", |
| 806 | in_bit_offset, service->notify_recv_bits, |
| 807 | out_bit_offset, service->notify_send_bits); |
| 808 | |
| 809 | /* Fill in the device's allocations */ |
| 810 | service->recv_quota = in_quota; |
| 811 | service->send_quota = out_quota; |
| 812 | service->notify_recv_offset = in_bit_offset; |
| 813 | service->notify_send_offset = out_bit_offset; |
| 814 | |
| 815 | mutex_unlock(&server->alloc_lock); |
| 816 | |
| 817 | return 0; |
| 818 | |
| 819 | fail_out_notify: |
| 820 | if (service->notify_recv_bits) |
| 821 | bitmap_clear(server->in_notify_map, |
| 822 | in_bit_offset, service->notify_recv_bits); |
| 823 | fail_in_notify: |
| 824 | server->out_quota_remaining += out_quota; |
| 825 | fail_out_quota: |
| 826 | server->in_quota_remaining += in_quota; |
| 827 | fail_in_quota: |
| 828 | |
| 829 | mutex_unlock(&server->alloc_lock); |
| 830 | |
| 831 | service->recv_quota = 0; |
| 832 | service->send_quota = 0; |
| 833 | service->notify_recv_bits = 0; |
| 834 | service->notify_recv_offset = 0; |
| 835 | service->notify_send_bits = 0; |
| 836 | service->notify_send_offset = 0; |
| 837 | |
| 838 | return ret; |
| 839 | } |
| 840 | |
| 841 | /* |
| 842 | * free_transport_resources - Frees the quotas and notification bits for |
| 843 | * a non-core service. |
| 844 | * @server: the core service state. |
| 845 | * @service: the service device to free resources for. |
| 846 | * |
| 847 | * This function is called by the server to free message quotas and |
| 848 | * notification bits that were allocated by alloc_transport_resources. It must |
| 849 | * only be called when the target service is in reset, and must be called with |
| 850 | * the core service's state lock held. |
| 851 | */ |
| 852 | static int free_transport_resources(struct core_server *server, |
| 853 | struct vs_service_device *service) |
| 854 | { |
| 855 | mutex_lock(&server->alloc_lock); |
| 856 | |
| 857 | if (service->notify_recv_bits) |
| 858 | bitmap_clear(server->in_notify_map, |
| 859 | service->notify_recv_offset, |
| 860 | service->notify_recv_bits); |
| 861 | |
| 862 | if (service->notify_send_bits) |
| 863 | bitmap_clear(server->out_notify_map, |
| 864 | service->notify_send_offset, |
| 865 | service->notify_send_bits); |
| 866 | |
| 867 | server->in_quota_remaining += service->recv_quota; |
| 868 | server->out_quota_remaining += service->send_quota; |
| 869 | |
| 870 | mutex_unlock(&server->alloc_lock); |
| 871 | |
| 872 | service->recv_quota = 0; |
| 873 | service->send_quota = 0; |
| 874 | service->notify_recv_bits = 0; |
| 875 | service->notify_recv_offset = 0; |
| 876 | service->notify_send_bits = 0; |
| 877 | service->notify_send_offset = 0; |
| 878 | |
| 879 | return 0; |
| 880 | } |
| 881 | |
| 882 | static struct vs_server_core_state * |
| 883 | vs_core_server_alloc(struct vs_service_device *service) |
| 884 | { |
| 885 | struct core_server *server; |
| 886 | int err; |
| 887 | |
| 888 | if (WARN_ON(service->id != 0)) |
| 889 | goto fail; |
| 890 | |
| 891 | server = kzalloc(sizeof(*server), GFP_KERNEL); |
| 892 | if (!server) |
| 893 | goto fail; |
| 894 | |
| 895 | server->service = service; |
| 896 | INIT_LIST_HEAD(&server->message_queue); |
| 897 | INIT_WORK(&server->message_queue_work, message_queue_work); |
| 898 | mutex_init(&server->message_queue_lock); |
| 899 | |
| 900 | err = init_transport_resource_allocation(server); |
| 901 | if (err) |
| 902 | goto fail_init_alloc; |
| 903 | |
| 904 | err = alloc_transport_resources(server, service); |
| 905 | if (err) |
| 906 | goto fail_alloc_transport; |
| 907 | |
| 908 | err = sysfs_create_group(&service->dev.kobj, &server_core_attr_group); |
| 909 | if (err) |
| 910 | goto fail_sysfs; |
| 911 | |
| 912 | return &server->state; |
| 913 | |
| 914 | fail_sysfs: |
| 915 | free_transport_resources(server, service); |
| 916 | fail_alloc_transport: |
| 917 | kfree(server->out_notify_map); |
| 918 | kfree(server->in_notify_map); |
| 919 | fail_init_alloc: |
| 920 | kfree(server); |
| 921 | fail: |
| 922 | return NULL; |
| 923 | } |
| 924 | |
| 925 | static void vs_core_server_release(struct vs_server_core_state *state) |
| 926 | { |
| 927 | struct core_server *server = to_core_server(state); |
| 928 | struct vs_session_device *session = vs_core_server_session(server); |
| 929 | |
| 930 | /* Delete all the other services */ |
| 931 | vs_session_delete_noncore(session); |
| 932 | |
| 933 | sysfs_remove_group(&server->service->dev.kobj, &server_core_attr_group); |
| 934 | kfree(server->out_notify_map); |
| 935 | kfree(server->in_notify_map); |
| 936 | kfree(server); |
| 937 | } |
| 938 | |
| 939 | /** |
| 940 | * vs_server_create_service - create and register a new vService server |
| 941 | * @session: the session to create the vService server on |
| 942 | * @parent: an existing server that is managing the new server |
| 943 | * @name: the name of the new service |
| 944 | * @protocol: the protocol for the new service |
| 945 | * @plat_data: value to be assigned to (struct device *)->platform_data |
| 946 | */ |
| 947 | struct vs_service_device * |
| 948 | vs_server_create_service(struct vs_session_device *session, |
| 949 | struct vs_service_device *parent, const char *name, |
| 950 | const char *protocol, const void *plat_data) |
| 951 | { |
| 952 | struct vs_service_device *core_service, *new_service; |
| 953 | struct core_server *server; |
| 954 | |
| 955 | if (!session->is_server || !name || !protocol) |
| 956 | return NULL; |
| 957 | |
| 958 | core_service = session->core_service; |
| 959 | if (!core_service) |
| 960 | return NULL; |
| 961 | |
| 962 | device_lock(&core_service->dev); |
| 963 | if (!core_service->dev.driver) { |
| 964 | device_unlock(&core_service->dev); |
| 965 | return NULL; |
| 966 | } |
| 967 | |
| 968 | server = dev_to_core_server(&core_service->dev); |
| 969 | |
| 970 | if (!parent) |
| 971 | parent = core_service; |
| 972 | |
| 973 | new_service = vs_server_core_create_service(server, session, parent, |
| 974 | VS_SERVICE_AUTO_ALLOCATE_ID, name, protocol, plat_data); |
| 975 | |
| 976 | device_unlock(&core_service->dev); |
| 977 | |
| 978 | if (IS_ERR(new_service)) |
| 979 | return NULL; |
| 980 | |
| 981 | return new_service; |
| 982 | } |
| 983 | EXPORT_SYMBOL(vs_server_create_service); |
| 984 | |
| 985 | /** |
| 986 | * vs_server_destroy_service - destroy and unregister a vService server. This |
| 987 | * function must _not_ be used from the target service's own workqueue. |
| 988 | * @service: The service to destroy |
| 989 | */ |
| 990 | int vs_server_destroy_service(struct vs_service_device *service, |
| 991 | struct vs_service_device *parent) |
| 992 | { |
| 993 | struct vs_session_device *session = vs_service_get_session(service); |
| 994 | |
| 995 | if (!session->is_server || service->id == 0) |
| 996 | return -EINVAL; |
| 997 | |
| 998 | if (!parent) |
| 999 | parent = session->core_service; |
| 1000 | |
| 1001 | return vs_service_delete(service, parent); |
| 1002 | } |
| 1003 | EXPORT_SYMBOL(vs_server_destroy_service); |
| 1004 | |
| 1005 | static void __queue_service_created(struct vs_service_device *service, |
| 1006 | void *data) |
| 1007 | { |
| 1008 | struct core_server *server = (struct core_server *)data; |
| 1009 | |
| 1010 | vs_server_core_queue_service_created(server, service); |
| 1011 | } |
| 1012 | |
| 1013 | static int vs_server_core_handle_connect(struct vs_server_core_state *state) |
| 1014 | { |
| 1015 | struct core_server *server = to_core_server(state); |
| 1016 | struct vs_session_device *session = vs_core_server_session(server); |
| 1017 | int err; |
| 1018 | |
| 1019 | /* Tell the other end that we've finished connecting. */ |
| 1020 | err = vs_server_core_core_send_ack_connect(state, GFP_KERNEL); |
| 1021 | if (err) |
| 1022 | return err; |
| 1023 | |
| 1024 | /* Queue a service-created message for each existing service. */ |
| 1025 | vs_session_for_each_service(session, __queue_service_created, server); |
| 1026 | |
| 1027 | /* Re-enable all the services. */ |
| 1028 | vs_session_enable_noncore(session); |
| 1029 | |
| 1030 | return 0; |
| 1031 | } |
| 1032 | |
| 1033 | static void vs_core_server_disable_services(struct core_server *server) |
| 1034 | { |
| 1035 | struct vs_session_device *session = vs_core_server_session(server); |
| 1036 | struct pending_message *msg; |
| 1037 | |
| 1038 | /* Disable all the other services */ |
| 1039 | vs_session_disable_noncore(session); |
| 1040 | |
| 1041 | /* Flush all the pending service-readiness messages */ |
| 1042 | mutex_lock(&server->message_queue_lock); |
| 1043 | while (!list_empty(&server->message_queue)) { |
| 1044 | msg = list_first_entry(&server->message_queue, |
| 1045 | struct pending_message, list); |
| 1046 | vs_put_service(msg->service); |
| 1047 | list_del(&msg->list); |
| 1048 | kfree(msg); |
| 1049 | } |
| 1050 | mutex_unlock(&server->message_queue_lock); |
| 1051 | } |
| 1052 | |
| 1053 | static int vs_server_core_handle_disconnect(struct vs_server_core_state *state) |
| 1054 | { |
| 1055 | struct core_server *server = to_core_server(state); |
| 1056 | |
| 1057 | vs_core_server_disable_services(server); |
| 1058 | |
| 1059 | return vs_server_core_core_send_ack_disconnect(state, GFP_KERNEL); |
| 1060 | } |
| 1061 | |
| 1062 | static int |
| 1063 | vs_server_core_handle_service_reset(struct vs_server_core_state *state, |
| 1064 | unsigned service_id) |
| 1065 | { |
| 1066 | struct core_server *server = to_core_server(state); |
| 1067 | struct vs_session_device *session = vs_core_server_session(server); |
| 1068 | |
| 1069 | if (service_id == 0) |
| 1070 | return -EPROTO; |
| 1071 | |
| 1072 | return vs_service_handle_reset(session, service_id, false); |
| 1073 | } |
| 1074 | |
| 1075 | static void vs_core_server_start(struct vs_server_core_state *state) |
| 1076 | { |
| 1077 | struct core_server *server = to_core_server(state); |
| 1078 | struct vs_session_device *session = vs_core_server_session(server); |
| 1079 | int err; |
| 1080 | |
| 1081 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &server->service->dev, |
| 1082 | "Core server start\n"); |
| 1083 | |
| 1084 | err = vs_server_core_core_send_startup(&server->state, |
| 1085 | server->service->recv_quota, |
| 1086 | server->service->send_quota, GFP_KERNEL); |
| 1087 | |
| 1088 | if (err) |
| 1089 | dev_err(&session->dev, "Failed to start core protocol: %d\n", |
| 1090 | err); |
| 1091 | } |
| 1092 | |
| 1093 | static void vs_core_server_reset(struct vs_server_core_state *state) |
| 1094 | { |
| 1095 | struct core_server *server = to_core_server(state); |
| 1096 | struct vs_session_device *session = vs_core_server_session(server); |
| 1097 | |
| 1098 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &server->service->dev, |
| 1099 | "Core server reset\n"); |
| 1100 | |
| 1101 | vs_core_server_disable_services(server); |
| 1102 | } |
| 1103 | |
| 1104 | static struct vs_server_core vs_core_server_driver = { |
| 1105 | .alloc = vs_core_server_alloc, |
| 1106 | .release = vs_core_server_release, |
| 1107 | .start = vs_core_server_start, |
| 1108 | .reset = vs_core_server_reset, |
| 1109 | .tx_ready = vs_core_server_tx_ready, |
| 1110 | .core = { |
| 1111 | .req_connect = vs_server_core_handle_connect, |
| 1112 | .req_disconnect = vs_server_core_handle_disconnect, |
| 1113 | .msg_service_reset = vs_server_core_handle_service_reset, |
| 1114 | }, |
| 1115 | }; |
| 1116 | |
| 1117 | /* |
| 1118 | * Server bus driver |
| 1119 | */ |
| 1120 | static int vs_server_bus_match(struct device *dev, struct device_driver *driver) |
| 1121 | { |
| 1122 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1123 | struct vs_service_driver *vsdrv = to_vs_service_driver(driver); |
| 1124 | |
| 1125 | /* Don't match anything to the devio driver; it's bound manually */ |
| 1126 | if (!vsdrv->protocol) |
| 1127 | return 0; |
| 1128 | |
| 1129 | WARN_ON_ONCE(!service->is_server || !vsdrv->is_server); |
| 1130 | |
| 1131 | /* Don't match anything that doesn't have a protocol set yet */ |
| 1132 | if (!service->protocol) |
| 1133 | return 0; |
| 1134 | |
| 1135 | if (strcmp(service->protocol, vsdrv->protocol) == 0) |
| 1136 | return 1; |
| 1137 | |
| 1138 | return 0; |
| 1139 | } |
| 1140 | |
| 1141 | static int vs_server_bus_probe(struct device *dev) |
| 1142 | { |
| 1143 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1144 | struct vs_session_device *session = vs_service_get_session(service); |
| 1145 | struct core_server *server = vs_server_session_core_server(session); |
| 1146 | int ret; |
| 1147 | |
| 1148 | /* |
| 1149 | * Set the notify counts for the service, unless the driver is the |
| 1150 | * devio driver in which case it has already been done by the devio |
| 1151 | * bind ioctl. The devio driver cannot be bound automatically. |
| 1152 | */ |
| 1153 | struct vs_service_driver *driver = |
| 1154 | to_vs_service_driver(service->dev.driver); |
| 1155 | #ifdef CONFIG_VSERVICES_CHAR_DEV |
| 1156 | if (driver != &vs_devio_server_driver) |
| 1157 | #endif |
| 1158 | { |
| 1159 | service->notify_recv_bits = driver->in_notify_count; |
| 1160 | service->notify_send_bits = driver->out_notify_count; |
| 1161 | } |
| 1162 | |
| 1163 | /* |
| 1164 | * We can't allocate transport resources here for the core service |
| 1165 | * because the resource pool doesn't exist yet. It's done in alloc() |
| 1166 | * instead (which is called, indirectly, by vs_service_bus_probe()). |
| 1167 | */ |
| 1168 | if (service->id == 0) |
| 1169 | return vs_service_bus_probe(dev); |
| 1170 | |
| 1171 | if (!server) |
| 1172 | return -ENODEV; |
| 1173 | ret = alloc_transport_resources(server, service); |
| 1174 | if (ret < 0) |
| 1175 | goto fail; |
| 1176 | |
| 1177 | ret = vs_service_bus_probe(dev); |
| 1178 | if (ret < 0) |
| 1179 | goto fail_free_resources; |
| 1180 | |
| 1181 | return 0; |
| 1182 | |
| 1183 | fail_free_resources: |
| 1184 | free_transport_resources(server, service); |
| 1185 | fail: |
| 1186 | return ret; |
| 1187 | } |
| 1188 | |
| 1189 | static int vs_server_bus_remove(struct device *dev) |
| 1190 | { |
| 1191 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1192 | struct vs_session_device *session = vs_service_get_session(service); |
| 1193 | struct core_server *server = vs_server_session_core_server(session); |
| 1194 | |
| 1195 | vs_service_bus_remove(dev); |
| 1196 | |
| 1197 | /* |
| 1198 | * We skip free_transport_resources for the core service because the |
| 1199 | * resource pool has already been freed at this point. It's also |
| 1200 | * possible that the core service has disappeared, in which case |
| 1201 | * there's no work to do here. |
| 1202 | */ |
| 1203 | if (server != NULL && service->id != 0) |
| 1204 | free_transport_resources(server, service); |
| 1205 | |
| 1206 | return 0; |
| 1207 | } |
| 1208 | |
| 1209 | static ssize_t is_server_show(struct device *dev, struct device_attribute *attr, |
| 1210 | char *buf) |
| 1211 | { |
| 1212 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1213 | |
| 1214 | return scnprintf(buf, PAGE_SIZE, "%d\n", service->is_server); |
| 1215 | } |
| 1216 | |
| 1217 | static ssize_t id_show(struct device *dev, struct device_attribute *attr, |
| 1218 | char *buf) |
| 1219 | { |
| 1220 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1221 | |
| 1222 | return scnprintf(buf, PAGE_SIZE, "%d\n", service->id); |
| 1223 | } |
| 1224 | |
| 1225 | static ssize_t dev_protocol_show(struct device *dev, |
| 1226 | struct device_attribute *attr, char *buf) |
| 1227 | { |
| 1228 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1229 | |
| 1230 | return scnprintf(buf, PAGE_SIZE, "%s\n", service->protocol ?: ""); |
| 1231 | } |
| 1232 | |
| 1233 | struct service_enable_work_struct { |
| 1234 | struct vs_service_device *service; |
| 1235 | struct work_struct work; |
| 1236 | }; |
| 1237 | |
| 1238 | static void service_enable_work(struct work_struct *work) |
| 1239 | { |
| 1240 | struct service_enable_work_struct *enable_work = container_of(work, |
| 1241 | struct service_enable_work_struct, work); |
| 1242 | struct vs_service_device *service = enable_work->service; |
| 1243 | struct vs_session_device *session = vs_service_get_session(service); |
| 1244 | struct core_server *server = vs_server_session_core_server(session); |
| 1245 | bool started; |
| 1246 | int ret; |
| 1247 | |
| 1248 | kfree(enable_work); |
| 1249 | |
| 1250 | if (!server) |
| 1251 | return; |
| 1252 | /* Start and enable the service */ |
| 1253 | vs_service_state_lock(server->service); |
| 1254 | started = vs_service_start(service); |
| 1255 | if (!started) { |
| 1256 | vs_service_state_unlock(server->service); |
| 1257 | vs_put_service(service); |
| 1258 | return; |
| 1259 | } |
| 1260 | |
| 1261 | if (VSERVICE_CORE_STATE_IS_CONNECTED(server->state.state.core)) |
| 1262 | vs_service_enable(service); |
| 1263 | vs_service_state_unlock(server->service); |
| 1264 | |
| 1265 | /* Tell the bus to search for a driver that supports the protocol */ |
| 1266 | ret = device_attach(&service->dev); |
| 1267 | if (ret == 0) |
| 1268 | dev_warn(&service->dev, "No driver found for protocol: %s\n", |
| 1269 | service->protocol); |
| 1270 | kobject_uevent(&service->dev.kobj, KOBJ_CHANGE); |
| 1271 | |
| 1272 | /* The corresponding vs_get_service was done when the work was queued */ |
| 1273 | vs_put_service(service); |
| 1274 | } |
| 1275 | |
| 1276 | static ssize_t dev_protocol_store(struct device *dev, |
| 1277 | struct device_attribute *attr, const char *buf, size_t count) |
| 1278 | { |
| 1279 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1280 | struct service_enable_work_struct *enable_work; |
| 1281 | |
| 1282 | /* The protocol can only be set once */ |
| 1283 | if (service->protocol) |
| 1284 | return -EPERM; |
| 1285 | |
| 1286 | /* Registering additional core servers is not allowed */ |
| 1287 | if (strcmp(buf, VSERVICE_CORE_PROTOCOL_NAME) == 0) |
| 1288 | return -EINVAL; |
| 1289 | |
| 1290 | if (strnlen(buf, VSERVICE_CORE_PROTOCOL_NAME_SIZE) + 1 > |
| 1291 | VSERVICE_CORE_PROTOCOL_NAME_SIZE) |
| 1292 | return -E2BIG; |
| 1293 | |
| 1294 | enable_work = kmalloc(sizeof(*enable_work), GFP_KERNEL); |
| 1295 | if (!enable_work) |
| 1296 | return -ENOMEM; |
| 1297 | |
| 1298 | /* Set the protocol and tell the client about it */ |
| 1299 | service->protocol = kstrdup(buf, GFP_KERNEL); |
| 1300 | if (!service->protocol) { |
| 1301 | kfree(enable_work); |
| 1302 | return -ENOMEM; |
| 1303 | } |
| 1304 | strim(service->protocol); |
| 1305 | |
| 1306 | /* |
| 1307 | * Schedule work to enable the service. We can't do it here because |
| 1308 | * we need to take the core service lock, and doing that here makes |
| 1309 | * it depend circularly on this sysfs attribute, which can be deleted |
| 1310 | * with that lock held. |
| 1311 | * |
| 1312 | * The corresponding vs_put_service is called in the enable_work |
| 1313 | * function. |
| 1314 | */ |
| 1315 | INIT_WORK(&enable_work->work, service_enable_work); |
| 1316 | enable_work->service = vs_get_service(service); |
| 1317 | schedule_work(&enable_work->work); |
| 1318 | |
| 1319 | return count; |
| 1320 | } |
| 1321 | |
| 1322 | static ssize_t service_name_show(struct device *dev, |
| 1323 | struct device_attribute *attr, char *buf) |
| 1324 | { |
| 1325 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1326 | |
| 1327 | return scnprintf(buf, PAGE_SIZE, "%s\n", service->name); |
| 1328 | } |
| 1329 | |
| 1330 | static ssize_t quota_in_store(struct device *dev, |
| 1331 | struct device_attribute *attr, const char *buf, size_t count) |
| 1332 | { |
| 1333 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1334 | struct vs_session_device *session = vs_service_get_session(service); |
| 1335 | struct core_server *server = vs_server_session_core_server(session); |
| 1336 | int ret; |
| 1337 | unsigned long in_quota; |
| 1338 | |
| 1339 | if (!server) |
| 1340 | return -ENODEV; |
| 1341 | /* |
| 1342 | * Don't allow quota to be changed for services that have a driver |
| 1343 | * bound. We take the alloc lock here because the device lock is held |
| 1344 | * while creating and destroying this sysfs item. This means we can |
| 1345 | * race with driver binding, but that doesn't matter: we actually just |
| 1346 | * want to know that alloc_transport_resources() hasn't run yet, and |
| 1347 | * that takes the alloc lock. |
| 1348 | */ |
| 1349 | mutex_lock(&server->alloc_lock); |
| 1350 | if (service->dev.driver) { |
| 1351 | ret = -EPERM; |
| 1352 | goto out; |
| 1353 | } |
| 1354 | |
| 1355 | ret = kstrtoul(buf, 0, &in_quota); |
| 1356 | if (ret < 0) |
| 1357 | goto out; |
| 1358 | |
| 1359 | service->in_quota_set = in_quota; |
| 1360 | ret = count; |
| 1361 | |
| 1362 | out: |
| 1363 | mutex_unlock(&server->alloc_lock); |
| 1364 | |
| 1365 | return ret; |
| 1366 | } |
| 1367 | |
| 1368 | static ssize_t quota_in_show(struct device *dev, |
| 1369 | struct device_attribute *attr, char *buf) |
| 1370 | { |
| 1371 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1372 | |
| 1373 | return scnprintf(buf, PAGE_SIZE, "%u\n", service->recv_quota); |
| 1374 | } |
| 1375 | |
| 1376 | static ssize_t quota_out_store(struct device *dev, |
| 1377 | struct device_attribute *attr, const char *buf, size_t count) |
| 1378 | { |
| 1379 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1380 | struct vs_session_device *session = vs_service_get_session(service); |
| 1381 | struct core_server *server = vs_server_session_core_server(session); |
| 1382 | int ret; |
| 1383 | unsigned long out_quota; |
| 1384 | |
| 1385 | if (!server) |
| 1386 | return -ENODEV; |
| 1387 | /* See comment in quota_in_store. */ |
| 1388 | mutex_lock(&server->alloc_lock); |
| 1389 | if (service->dev.driver) { |
| 1390 | ret = -EPERM; |
| 1391 | goto out; |
| 1392 | } |
| 1393 | |
| 1394 | ret = kstrtoul(buf, 0, &out_quota); |
| 1395 | if (ret < 0) |
| 1396 | goto out; |
| 1397 | |
| 1398 | service->out_quota_set = out_quota; |
| 1399 | ret = count; |
| 1400 | |
| 1401 | out: |
| 1402 | mutex_unlock(&server->alloc_lock); |
| 1403 | |
| 1404 | return ret; |
| 1405 | } |
| 1406 | |
| 1407 | static ssize_t quota_out_show(struct device *dev, |
| 1408 | struct device_attribute *attr, char *buf) |
| 1409 | { |
| 1410 | struct vs_service_device *service = to_vs_service_device(dev); |
| 1411 | |
| 1412 | return scnprintf(buf, PAGE_SIZE, "%u\n", service->send_quota); |
| 1413 | } |
| 1414 | |
| 1415 | static struct device_attribute vs_server_dev_attrs[] = { |
| 1416 | __ATTR_RO(id), |
| 1417 | __ATTR_RO(is_server), |
| 1418 | __ATTR(protocol, S_IRUGO | S_IWUSR, |
| 1419 | dev_protocol_show, dev_protocol_store), |
| 1420 | __ATTR_RO(service_name), |
| 1421 | __ATTR(quota_in, S_IRUGO | S_IWUSR, |
| 1422 | quota_in_show, quota_in_store), |
| 1423 | __ATTR(quota_out, S_IRUGO | S_IWUSR, |
| 1424 | quota_out_show, quota_out_store), |
| 1425 | __ATTR_NULL |
| 1426 | }; |
| 1427 | |
| 1428 | static ssize_t protocol_show(struct device_driver *drv, char *buf) |
| 1429 | { |
| 1430 | struct vs_service_driver *vsdrv = to_vs_service_driver(drv); |
| 1431 | |
| 1432 | return scnprintf(buf, PAGE_SIZE, "%s\n", vsdrv->protocol); |
| 1433 | } |
| 1434 | |
| 1435 | #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0) |
| 1436 | static struct driver_attribute vs_server_drv_attrs[] = { |
| 1437 | __ATTR_RO(protocol), |
| 1438 | __ATTR_NULL |
| 1439 | }; |
| 1440 | #else |
| 1441 | static DRIVER_ATTR_RO(protocol); |
| 1442 | |
| 1443 | static struct attribute *vs_server_drv_attrs[] = { |
| 1444 | &driver_attr_protocol.attr, |
| 1445 | NULL, |
| 1446 | }; |
| 1447 | ATTRIBUTE_GROUPS(vs_server_drv); |
| 1448 | #endif |
| 1449 | |
| 1450 | struct bus_type vs_server_bus_type = { |
| 1451 | .name = "vservices-server", |
| 1452 | .dev_attrs = vs_server_dev_attrs, |
| 1453 | #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 14, 0) |
| 1454 | .drv_attrs = vs_server_drv_attrs, |
| 1455 | #else |
| 1456 | .drv_groups = vs_server_drv_groups, |
| 1457 | #endif |
| 1458 | .match = vs_server_bus_match, |
| 1459 | .probe = vs_server_bus_probe, |
| 1460 | .remove = vs_server_bus_remove, |
| 1461 | .uevent = vs_service_bus_uevent, |
| 1462 | }; |
| 1463 | EXPORT_SYMBOL(vs_server_bus_type); |
| 1464 | |
| 1465 | /* |
| 1466 | * Server session driver |
| 1467 | */ |
| 1468 | static int vs_server_session_probe(struct device *dev) |
| 1469 | { |
| 1470 | struct vs_session_device *session = to_vs_session_device(dev); |
| 1471 | struct vs_service_device *service; |
| 1472 | |
| 1473 | service = __vs_server_core_register_service(session, 0, NULL, |
| 1474 | VSERVICE_CORE_SERVICE_NAME, |
| 1475 | VSERVICE_CORE_PROTOCOL_NAME, NULL); |
| 1476 | if (IS_ERR(service)) |
| 1477 | return PTR_ERR(service); |
| 1478 | |
| 1479 | return 0; |
| 1480 | } |
| 1481 | |
| 1482 | static int |
| 1483 | vs_server_session_service_added(struct vs_session_device *session, |
| 1484 | struct vs_service_device *service) |
| 1485 | { |
| 1486 | struct core_server *server = vs_server_session_core_server(session); |
| 1487 | int err; |
| 1488 | |
| 1489 | if (WARN_ON(!server || !service->id)) |
| 1490 | return -EINVAL; |
| 1491 | |
| 1492 | err = vs_server_core_queue_service_created(server, service); |
| 1493 | |
| 1494 | if (err) |
| 1495 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &session->dev, |
| 1496 | "failed to send service_created: %d\n", err); |
| 1497 | |
| 1498 | return err; |
| 1499 | } |
| 1500 | |
| 1501 | static int |
| 1502 | vs_server_session_service_start(struct vs_session_device *session, |
| 1503 | struct vs_service_device *service) |
| 1504 | { |
| 1505 | struct core_server *server = vs_server_session_core_server(session); |
| 1506 | int err; |
| 1507 | |
| 1508 | if (WARN_ON(!server || !service->id)) |
| 1509 | return -EINVAL; |
| 1510 | |
| 1511 | err = vs_server_core_queue_service_reset_ready(server, |
| 1512 | VSERVICE_CORE_CORE_MSG_SERVER_READY, service); |
| 1513 | |
| 1514 | if (err) |
| 1515 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &session->dev, |
| 1516 | "failed to send server_ready: %d\n", err); |
| 1517 | |
| 1518 | return err; |
| 1519 | } |
| 1520 | |
| 1521 | static int |
| 1522 | vs_server_session_service_local_reset(struct vs_session_device *session, |
| 1523 | struct vs_service_device *service) |
| 1524 | { |
| 1525 | struct core_server *server = vs_server_session_core_server(session); |
| 1526 | int err; |
| 1527 | |
| 1528 | if (WARN_ON(!server || !service->id)) |
| 1529 | return -EINVAL; |
| 1530 | |
| 1531 | err = vs_server_core_queue_service_reset_ready(server, |
| 1532 | VSERVICE_CORE_CORE_MSG_SERVICE_RESET, service); |
| 1533 | |
| 1534 | if (err) |
| 1535 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &session->dev, |
| 1536 | "failed to send service_reset: %d\n", err); |
| 1537 | |
| 1538 | return err; |
| 1539 | } |
| 1540 | |
| 1541 | static int |
| 1542 | vs_server_session_service_removed(struct vs_session_device *session, |
| 1543 | struct vs_service_device *service) |
| 1544 | { |
| 1545 | struct core_server *server = vs_server_session_core_server(session); |
| 1546 | int err; |
| 1547 | |
| 1548 | /* |
| 1549 | * It's possible for the core server to be forcibly removed before |
| 1550 | * the other services, for example when the underlying transport |
| 1551 | * vanishes. If that happens, we can end up here with a NULL core |
| 1552 | * server pointer. |
| 1553 | */ |
| 1554 | if (!server) |
| 1555 | return 0; |
| 1556 | |
| 1557 | if (WARN_ON(!service->id)) |
| 1558 | return -EINVAL; |
| 1559 | |
| 1560 | err = vs_server_core_queue_service_removed(server, service); |
| 1561 | if (err) |
| 1562 | vs_dev_debug(VS_DEBUG_SERVER_CORE, session, &session->dev, |
| 1563 | "failed to send service_removed: %d\n", err); |
| 1564 | |
| 1565 | return err; |
| 1566 | } |
| 1567 | |
| 1568 | static struct vs_session_driver vs_server_session_driver = { |
| 1569 | .driver = { |
| 1570 | .name = "vservices-server-session", |
| 1571 | .owner = THIS_MODULE, |
| 1572 | .bus = &vs_session_bus_type, |
| 1573 | .probe = vs_server_session_probe, |
| 1574 | .suppress_bind_attrs = true, |
| 1575 | }, |
| 1576 | .is_server = true, |
| 1577 | .service_bus = &vs_server_bus_type, |
| 1578 | .service_added = vs_server_session_service_added, |
| 1579 | .service_start = vs_server_session_service_start, |
| 1580 | .service_local_reset = vs_server_session_service_local_reset, |
| 1581 | .service_removed = vs_server_session_service_removed, |
| 1582 | }; |
| 1583 | |
| 1584 | static int __init vs_core_server_init(void) |
| 1585 | { |
| 1586 | int ret; |
| 1587 | |
| 1588 | ret = bus_register(&vs_server_bus_type); |
| 1589 | if (ret) |
| 1590 | goto fail_bus_register; |
| 1591 | |
| 1592 | #ifdef CONFIG_VSERVICES_CHAR_DEV |
| 1593 | vs_devio_server_driver.driver.bus = &vs_server_bus_type; |
| 1594 | vs_devio_server_driver.driver.owner = THIS_MODULE; |
| 1595 | ret = driver_register(&vs_devio_server_driver.driver); |
| 1596 | if (ret) |
| 1597 | goto fail_devio_register; |
| 1598 | #endif |
| 1599 | |
| 1600 | ret = driver_register(&vs_server_session_driver.driver); |
| 1601 | if (ret) |
| 1602 | goto fail_driver_register; |
| 1603 | |
| 1604 | ret = vservice_core_server_register(&vs_core_server_driver, |
| 1605 | "vs_core_server"); |
| 1606 | if (ret) |
| 1607 | goto fail_core_register; |
| 1608 | |
| 1609 | vservices_server_root = kobject_create_and_add("server-sessions", |
| 1610 | vservices_root); |
| 1611 | if (!vservices_server_root) { |
| 1612 | ret = -ENOMEM; |
| 1613 | goto fail_create_root; |
| 1614 | } |
| 1615 | |
| 1616 | return 0; |
| 1617 | |
| 1618 | fail_create_root: |
| 1619 | vservice_core_server_unregister(&vs_core_server_driver); |
| 1620 | fail_core_register: |
| 1621 | driver_unregister(&vs_server_session_driver.driver); |
| 1622 | fail_driver_register: |
| 1623 | #ifdef CONFIG_VSERVICES_CHAR_DEV |
| 1624 | driver_unregister(&vs_devio_server_driver.driver); |
| 1625 | vs_devio_server_driver.driver.bus = NULL; |
| 1626 | vs_devio_server_driver.driver.owner = NULL; |
| 1627 | fail_devio_register: |
| 1628 | #endif |
| 1629 | bus_unregister(&vs_server_bus_type); |
| 1630 | fail_bus_register: |
| 1631 | return ret; |
| 1632 | } |
| 1633 | |
| 1634 | static void __exit vs_core_server_exit(void) |
| 1635 | { |
| 1636 | kobject_put(vservices_server_root); |
| 1637 | vservice_core_server_unregister(&vs_core_server_driver); |
| 1638 | driver_unregister(&vs_server_session_driver.driver); |
| 1639 | #ifdef CONFIG_VSERVICES_CHAR_DEV |
| 1640 | driver_unregister(&vs_devio_server_driver.driver); |
| 1641 | vs_devio_server_driver.driver.bus = NULL; |
| 1642 | vs_devio_server_driver.driver.owner = NULL; |
| 1643 | #endif |
| 1644 | bus_unregister(&vs_server_bus_type); |
| 1645 | } |
| 1646 | |
| 1647 | subsys_initcall(vs_core_server_init); |
| 1648 | module_exit(vs_core_server_exit); |
| 1649 | |
| 1650 | MODULE_DESCRIPTION("OKL4 Virtual Services Core Server Driver"); |
| 1651 | MODULE_AUTHOR("Open Kernel Labs, Inc"); |