/* * Copyright (c) 2006 Ondrej Palkovsky * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /** @addtogroup genericipc * @{ */ /** @file */ /* Lock ordering * * First the answerbox, then the phone. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** Open channel that is assigned automatically to new tasks */ answerbox_t *ipc_phone_0 = NULL; static slab_cache_t *ipc_call_slab; static slab_cache_t *ipc_answerbox_slab; /** Initialize a call structure. * * @param call Call structure to be initialized. * */ static void _ipc_call_init(call_t *call) { memsetb(call, sizeof(*call), 0); call->callerbox = &TASK->answerbox; call->sender = TASK; call->buffer = NULL; } /** Allocate and initialize a call structure. * * The call is initialized, so that the reply will be directed to * TASK->answerbox. * * @param flags Parameters for slab_alloc (e.g FRAME_ATOMIC). * * @return If flags permit it, return NULL, or initialized kernel * call structure. * */ call_t *ipc_call_alloc(unsigned int flags) { call_t *call = slab_alloc(ipc_call_slab, flags); if (call) _ipc_call_init(call); return call; } /** Deallocate a call structure. * * @param call Call structure to be freed. * */ void ipc_call_free(call_t *call) { /* Check to see if we have data in the IPC_M_DATA_SEND buffer. */ if (call->buffer) free(call->buffer); slab_free(ipc_call_slab, call); } /** Initialize an answerbox structure. * * @param box Answerbox structure to be initialized. * @param task Task to which the answerbox belongs. * */ void ipc_answerbox_init(answerbox_t *box, task_t *task) { irq_spinlock_initialize(&box->lock, "ipc.box.lock"); irq_spinlock_initialize(&box->irq_lock, "ipc.box.irqlock"); waitq_initialize(&box->wq); link_initialize(&box->sync_box_link); list_initialize(&box->connected_phones); list_initialize(&box->calls); list_initialize(&box->dispatched_calls); list_initialize(&box->answers); list_initialize(&box->irq_notifs); list_initialize(&box->irq_head); box->task = task; } /** Connect a phone to an answerbox. * * @param phone Initialized phone structure. * @param box Initialized answerbox structure. * */ void ipc_phone_connect(phone_t *phone, answerbox_t *box) { mutex_lock(&phone->lock); phone->state = IPC_PHONE_CONNECTED; phone->callee = box; irq_spinlock_lock(&box->lock, true); list_append(&phone->link, &box->connected_phones); irq_spinlock_unlock(&box->lock, true); mutex_unlock(&phone->lock); } /** Initialize a phone structure. * * @param phone Phone structure to be initialized. * */ void ipc_phone_init(phone_t *phone) { mutex_initialize(&phone->lock, MUTEX_PASSIVE); phone->callee = NULL; phone->state = IPC_PHONE_FREE; atomic_set(&phone->active_calls, 0); } /** Helper function to facilitate synchronous calls. * * @param phone Destination kernel phone structure. * @param request Call structure with request. * * @return EOK on success or EINTR if the sleep was interrupted. * */ int ipc_call_sync(phone_t *phone, call_t *request) { answerbox_t *sync_box = slab_alloc(ipc_answerbox_slab, 0); ipc_answerbox_init(sync_box, TASK); /* * Put the answerbox on the TASK's list of synchronous answerboxes so * that it can be cleaned up if the call is interrupted. */ irq_spinlock_lock(&TASK->lock, true); list_append(&sync_box->sync_box_link, &TASK->sync_box_head); irq_spinlock_unlock(&TASK->lock, true); /* We will receive data in a special box. */ request->callerbox = sync_box; ipc_call(phone, request); if (!ipc_wait_for_call(sync_box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_INTERRUPTIBLE)) { /* The answerbox and the call will be freed by ipc_cleanup(). */ return EINTR; } /* * The answer arrived without interruption so we can remove the * answerbox from the TASK's list of synchronous answerboxes. */ irq_spinlock_lock(&TASK->lock, true); list_remove(&sync_box->sync_box_link); irq_spinlock_unlock(&TASK->lock, true); slab_free(ipc_answerbox_slab, sync_box); return EOK; } /** Answer a message which was not dispatched and is not listed in any queue. * * @param call Call structure to be answered. * @param selflocked If true, then TASK->answebox is locked. * */ static void _ipc_answer_free_call(call_t *call, bool selflocked) { answerbox_t *callerbox = call->callerbox; bool do_lock = ((!selflocked) || callerbox != (&TASK->answerbox)); /* Count sent answer */ irq_spinlock_lock(&TASK->lock, true); TASK->ipc_info.answer_sent++; irq_spinlock_unlock(&TASK->lock, true); call->flags |= IPC_CALL_ANSWERED; if (call->flags & IPC_CALL_FORWARDED) { if (call->caller_phone) { /* Demasquerade the caller phone. */ call->data.phone = call->caller_phone; } } if (do_lock) irq_spinlock_lock(&callerbox->lock, true); list_append(&call->link, &callerbox->answers); if (do_lock) irq_spinlock_unlock(&callerbox->lock, true); waitq_wakeup(&callerbox->wq, WAKEUP_FIRST); } /** Answer a message which is in a callee queue. * * @param box Answerbox that is answering the message. * @param call Modified request that is being sent back. * */ void ipc_answer(answerbox_t *box, call_t *call) { /* Remove from active box */ irq_spinlock_lock(&box->lock, true); list_remove(&call->link); irq_spinlock_unlock(&box->lock, true); /* Send back answer */ _ipc_answer_free_call(call, false); } /** Simulate sending back a message. * * Most errors are better handled by forming a normal backward * message and sending it as a normal answer. * * @param phone Phone structure the call should appear to come from. * @param call Call structure to be answered. * @param err Return value to be used for the answer. * */ void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err) { call->data.phone = phone; atomic_inc(&phone->active_calls); IPC_SET_RETVAL(call->data, err); _ipc_answer_free_call(call, false); } /** Unsafe unchecking version of ipc_call. * * @param phone Phone structure the call comes from. * @param box Destination answerbox structure. * @param call Call structure with request. * */ static void _ipc_call(phone_t *phone, answerbox_t *box, call_t *call) { /* Count sent ipc call */ irq_spinlock_lock(&TASK->lock, true); TASK->ipc_info.call_sent++; irq_spinlock_unlock(&TASK->lock, true); if (!(call->flags & IPC_CALL_FORWARDED)) { atomic_inc(&phone->active_calls); call->data.phone = phone; } irq_spinlock_lock(&box->lock, true); list_append(&call->link, &box->calls); irq_spinlock_unlock(&box->lock, true); waitq_wakeup(&box->wq, WAKEUP_FIRST); } /** Send an asynchronous request using a phone to an answerbox. * * @param phone Phone structure the call comes from and which is * connected to the destination answerbox. * @param call Call structure with request. * * @return Return 0 on success, ENOENT on error. * */ int ipc_call(phone_t *phone, call_t *call) { mutex_lock(&phone->lock); if (phone->state != IPC_PHONE_CONNECTED) { mutex_unlock(&phone->lock); if (call->flags & IPC_CALL_FORWARDED) { IPC_SET_RETVAL(call->data, EFORWARD); _ipc_answer_free_call(call, false); } else { if (phone->state == IPC_PHONE_HUNGUP) ipc_backsend_err(phone, call, EHANGUP); else ipc_backsend_err(phone, call, ENOENT); } return ENOENT; } answerbox_t *box = phone->callee; _ipc_call(phone, box, call); mutex_unlock(&phone->lock); return 0; } /** Disconnect phone from answerbox. * * This call leaves the phone in the HUNGUP state. The change to 'free' is done * lazily later. * * @param phone Phone structure to be hung up. * * @return 0 if the phone is disconnected. * @return -1 if the phone was already disconnected. * */ int ipc_phone_hangup(phone_t *phone) { mutex_lock(&phone->lock); if (phone->state == IPC_PHONE_FREE || phone->state == IPC_PHONE_HUNGUP || phone->state == IPC_PHONE_CONNECTING) { mutex_unlock(&phone->lock); return -1; } answerbox_t *box = phone->callee; if (phone->state != IPC_PHONE_SLAMMED) { /* Remove myself from answerbox */ irq_spinlock_lock(&box->lock, true); list_remove(&phone->link); irq_spinlock_unlock(&box->lock, true); call_t *call = ipc_call_alloc(0); IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP); call->flags |= IPC_CALL_DISCARD_ANSWER; _ipc_call(phone, box, call); } phone->state = IPC_PHONE_HUNGUP; mutex_unlock(&phone->lock); return 0; } /** Forwards call from one answerbox to another one. * * @param call Call structure to be redirected. * @param newphone Phone structure to target answerbox. * @param oldbox Old answerbox structure. * @param mode Flags that specify mode of the forward operation. * * @return 0 if forwarding succeeded or an error code if * there was an error. * * The return value serves only as an information for the forwarder, * the original caller is notified automatically with EFORWARD. * */ int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox, unsigned int mode) { /* Count forwarded calls */ irq_spinlock_lock(&TASK->lock, true); TASK->ipc_info.forwarded++; irq_spinlock_pass(&TASK->lock, &oldbox->lock); list_remove(&call->link); irq_spinlock_unlock(&oldbox->lock, true); if (mode & IPC_FF_ROUTE_FROM_ME) { if (!call->caller_phone) call->caller_phone = call->data.phone; call->data.phone = newphone; } return ipc_call(newphone, call); } /** Wait for a phone call. * * @param box Answerbox expecting the call. * @param usec Timeout in microseconds. See documentation for * waitq_sleep_timeout() for decription of its special * meaning. * @param flags Select mode of sleep operation. See documentation for * waitq_sleep_timeout() for description of its special * meaning. * * @return Recived call structure or NULL. * * To distinguish between a call and an answer, have a look at call->flags. * */ call_t *ipc_wait_for_call(answerbox_t *box, uint32_t usec, unsigned int flags) { call_t *request; uint64_t irq_cnt = 0; uint64_t answer_cnt = 0; uint64_t call_cnt = 0; int rc; restart: rc = waitq_sleep_timeout(&box->wq, usec, flags); if (SYNCH_FAILED(rc)) return NULL; irq_spinlock_lock(&box->lock, true); if (!list_empty(&box->irq_notifs)) { /* Count received IRQ notification */ irq_cnt++; irq_spinlock_lock(&box->irq_lock, false); request = list_get_instance(box->irq_notifs.next, call_t, link); list_remove(&request->link); irq_spinlock_unlock(&box->irq_lock, false); } else if (!list_empty(&box->answers)) { /* Count received answer */ answer_cnt++; /* Handle asynchronous answers */ request = list_get_instance(box->answers.next, call_t, link); list_remove(&request->link); atomic_dec(&request->data.phone->active_calls); } else if (!list_empty(&box->calls)) { /* Count received call */ call_cnt++; /* Handle requests */ request = list_get_instance(box->calls.next, call_t, link); list_remove(&request->link); /* Append request to dispatch queue */ list_append(&request->link, &box->dispatched_calls); } else { /* This can happen regularly after ipc_cleanup */ irq_spinlock_unlock(&box->lock, true); goto restart; } irq_spinlock_pass(&box->lock, &TASK->lock); TASK->ipc_info.irq_notif_received += irq_cnt; TASK->ipc_info.answer_received += answer_cnt; TASK->ipc_info.call_received += call_cnt; irq_spinlock_unlock(&TASK->lock, true); return request; } /** Answer all calls from list with EHANGUP answer. * * @param lst Head of the list to be cleaned up. * */ void ipc_cleanup_call_list(link_t *lst) { while (!list_empty(lst)) { call_t *call = list_get_instance(lst->next, call_t, link); if (call->buffer) free(call->buffer); list_remove(&call->link); IPC_SET_RETVAL(call->data, EHANGUP); _ipc_answer_free_call(call, true); } } /** Disconnects all phones connected to an answerbox. * * @param box Answerbox to disconnect phones from. * @param notify_box If true, the answerbox will get a hangup message for * each disconnected phone. * */ void ipc_answerbox_slam_phones(answerbox_t *box, bool notify_box) { phone_t *phone; DEADLOCK_PROBE_INIT(p_phonelck); call_t *call = notify_box ? ipc_call_alloc(0) : NULL; /* Disconnect all phones connected to our answerbox */ restart_phones: irq_spinlock_lock(&box->lock, true); while (!list_empty(&box->connected_phones)) { phone = list_get_instance(box->connected_phones.next, phone_t, link); if (SYNCH_FAILED(mutex_trylock(&phone->lock))) { irq_spinlock_unlock(&box->lock, true); DEADLOCK_PROBE(p_phonelck, DEADLOCK_THRESHOLD); goto restart_phones; } /* Disconnect phone */ ASSERT(phone->state == IPC_PHONE_CONNECTED); list_remove(&phone->link); phone->state = IPC_PHONE_SLAMMED; if (notify_box) { mutex_unlock(&phone->lock); irq_spinlock_unlock(&box->lock, true); /* * Send one message to the answerbox for each * phone. Used to make sure the kbox thread * wakes up after the last phone has been * disconnected. */ IPC_SET_METHOD(call->data, IPC_M_PHONE_HUNGUP); call->flags |= IPC_CALL_DISCARD_ANSWER; _ipc_call(phone, box, call); /* Allocate another call in advance */ call = ipc_call_alloc(0); /* Must start again */ goto restart_phones; } mutex_unlock(&phone->lock); } irq_spinlock_unlock(&box->lock, true); /* Free unused call */ if (call) ipc_call_free(call); } /** Clean up all IPC communication of the current task. * * Note: ipc_hangup sets returning answerbox to TASK->answerbox, you * have to change it as well if you want to cleanup other tasks than TASK. * */ void ipc_cleanup(void) { /* Disconnect all our phones ('ipc_phone_hangup') */ size_t i; for (i = 0; i < IPC_MAX_PHONES; i++) ipc_phone_hangup(&TASK->phones[i]); /* Unsubscribe from any event notifications. */ event_cleanup_answerbox(&TASK->answerbox); /* Disconnect all connected irqs */ ipc_irq_cleanup(&TASK->answerbox); /* Disconnect all phones connected to our regular answerbox */ ipc_answerbox_slam_phones(&TASK->answerbox, false); #ifdef CONFIG_UDEBUG /* Clean up kbox thread and communications */ ipc_kbox_cleanup(); #endif /* Answer all messages in 'calls' and 'dispatched_calls' queues */ irq_spinlock_lock(&TASK->answerbox.lock, true); ipc_cleanup_call_list(&TASK->answerbox.dispatched_calls); ipc_cleanup_call_list(&TASK->answerbox.calls); irq_spinlock_unlock(&TASK->answerbox.lock, true); /* Wait for all answers to interrupted synchronous calls to arrive */ ipl_t ipl = interrupts_disable(); while (!list_empty(&TASK->sync_box_head)) { answerbox_t *box = list_get_instance(TASK->sync_box_head.next, answerbox_t, sync_box_link); list_remove(&box->sync_box_link); call_t *call = ipc_wait_for_call(box, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE); ipc_call_free(call); slab_free(ipc_answerbox_slab, box); } interrupts_restore(ipl); /* Wait for all answers to asynchronous calls to arrive */ while (true) { /* * Go through all phones, until they are all FREE * Locking is not needed, no one else should modify * it when we are in cleanup */ for (i = 0; i < IPC_MAX_PHONES; i++) { if (TASK->phones[i].state == IPC_PHONE_HUNGUP && atomic_get(&TASK->phones[i].active_calls) == 0) { TASK->phones[i].state = IPC_PHONE_FREE; TASK->phones[i].callee = NULL; } /* * Just for sure, we might have had some * IPC_PHONE_CONNECTING phones */ if (TASK->phones[i].state == IPC_PHONE_CONNECTED) ipc_phone_hangup(&TASK->phones[i]); /* * If the hangup succeeded, it has sent a HANGUP * message, the IPC is now in HUNGUP state, we * wait for the reply to come */ if (TASK->phones[i].state != IPC_PHONE_FREE) break; } /* Got into cleanup */ if (i == IPC_MAX_PHONES) break; call_t *call = ipc_wait_for_call(&TASK->answerbox, SYNCH_NO_TIMEOUT, SYNCH_FLAGS_NONE); ASSERT((call->flags & IPC_CALL_ANSWERED) || (call->flags & IPC_CALL_NOTIF)); /* * Record the receipt of this call in the current task's counter * of active calls. IPC_M_PHONE_HUNGUP calls do not contribute * to this counter so do not record answers to them either. */ if (!(call->flags & IPC_CALL_DISCARD_ANSWER)) atomic_dec(&TASK->active_calls); ipc_call_free(call); } } /** Initilize IPC subsystem * */ void ipc_init(void) { ipc_call_slab = slab_cache_create("ipc_call", sizeof(call_t), 0, NULL, NULL, 0); ipc_answerbox_slab = slab_cache_create("ipc_answerbox", sizeof(answerbox_t), 0, NULL, NULL, 0); } /** List answerbox contents. * * @param taskid Task ID. * */ void ipc_print_task(task_id_t taskid) { irq_spinlock_lock(&tasks_lock, true); task_t *task = task_find_by_id(taskid); if (!task) { irq_spinlock_unlock(&tasks_lock, true); return; } /* Hand-over-hand locking */ irq_spinlock_exchange(&tasks_lock, &task->lock); /* Print opened phones & details */ printf("PHONE:\n"); size_t i; for (i = 0; i < IPC_MAX_PHONES; i++) { if (SYNCH_FAILED(mutex_trylock(&task->phones[i].lock))) { printf("%zu: mutex busy\n", i); continue; } if (task->phones[i].state != IPC_PHONE_FREE) { printf("%zu: ", i); switch (task->phones[i].state) { case IPC_PHONE_CONNECTING: printf("connecting "); break; case IPC_PHONE_CONNECTED: printf("connected to: %p ", task->phones[i].callee); break; case IPC_PHONE_SLAMMED: printf("slammed by: %p ", task->phones[i].callee); break; case IPC_PHONE_HUNGUP: printf("hung up - was: %p ", task->phones[i].callee); break; default: break; } printf("active: %" PRIun "\n", atomic_get(&task->phones[i].active_calls)); } mutex_unlock(&task->phones[i].lock); } irq_spinlock_lock(&task->answerbox.lock, false); link_t *cur; /* Print answerbox - calls */ printf("ABOX - CALLS:\n"); for (cur = task->answerbox.calls.next; cur != &task->answerbox.calls; cur = cur->next) { call_t *call = list_get_instance(cur, call_t, link); printf("Callid: %p Srctask:%" PRIu64 " M:%" PRIun " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call, call->sender->taskid, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data), IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data), call->flags); } /* Print answerbox - dispatched calls */ printf("ABOX - DISPATCHED CALLS:\n"); for (cur = task->answerbox.dispatched_calls.next; cur != &task->answerbox.dispatched_calls; cur = cur->next) { call_t *call = list_get_instance(cur, call_t, link); printf("Callid: %p Srctask:%" PRIu64 " M:%" PRIun " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call, call->sender->taskid, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data), IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data), call->flags); } /* Print answerbox - answers */ printf("ABOX - ANSWERS:\n"); for (cur = task->answerbox.answers.next; cur != &task->answerbox.answers; cur = cur->next) { call_t *call = list_get_instance(cur, call_t, link); printf("Callid:%p M:%" PRIun " A1:%" PRIun " A2:%" PRIun " A3:%" PRIun " A4:%" PRIun " A5:%" PRIun " Flags:%x\n", call, IPC_GET_METHOD(call->data), IPC_GET_ARG1(call->data), IPC_GET_ARG2(call->data), IPC_GET_ARG3(call->data), IPC_GET_ARG4(call->data), IPC_GET_ARG5(call->data), call->flags); } irq_spinlock_unlock(&task->answerbox.lock, false); irq_spinlock_unlock(&task->lock, true); } /** @} */