/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2002 by Björn Stenberg * * All files in this archive are subject to the GNU General Public License. * See the file COPYING in the source tree root for full license agreement. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include #include #include "config.h" #include "kernel.h" #ifdef SIMULATOR #include "system-sdl.h" #include "debug.h" #endif #include "thread.h" #include "cpu.h" #include "system.h" #include "panic.h" /* Make this nonzero to enable more elaborate checks on objects */ #if defined(DEBUG) || defined(SIMULATOR) #define KERNEL_OBJECT_CHECKS 1 /* Always 1 for DEBUG and sim*/ #else #define KERNEL_OBJECT_CHECKS 0 #endif #if KERNEL_OBJECT_CHECKS #ifdef SIMULATOR #define KERNEL_ASSERT(exp, msg...) \ ({ if (!({ exp; })) { DEBUGF(msg); exit(-1); } }) #else #define KERNEL_ASSERT(exp, msg...) \ ({ if (!({ exp; })) panicf(msg); }) #endif #else #define KERNEL_ASSERT(exp, msg...) ({}) #endif #if !defined(CPU_PP) || !defined(BOOTLOADER) volatile long current_tick NOCACHEDATA_ATTR = 0; #endif void (*tick_funcs[MAX_NUM_TICK_TASKS])(void); extern struct core_entry cores[NUM_CORES]; /* This array holds all queues that are initiated. It is used for broadcast. */ static struct { int count; struct event_queue *queues[MAX_NUM_QUEUES]; IF_COP( struct corelock cl; ) } all_queues NOCACHEBSS_ATTR; /**************************************************************************** * Standard kernel stuff ****************************************************************************/ void kernel_init(void) { /* Init the threading API */ init_threads(); /* Other processors will not reach this point in a multicore build. * In a single-core build with multiple cores they fall-through and * sleep in cop_main without returning. */ if (CURRENT_CORE == CPU) { memset(tick_funcs, 0, sizeof(tick_funcs)); memset(&all_queues, 0, sizeof(all_queues)); corelock_init(&all_queues.cl); tick_start(1000/HZ); } } /**************************************************************************** * Timer tick ****************************************************************************/ #if CONFIG_CPU == SH7034 void tick_start(unsigned int interval_in_ms) { unsigned long count; count = CPU_FREQ * interval_in_ms / 1000 / 8; if(count > 0x10000) { panicf("Error! The tick interval is too long (%d ms)\n", interval_in_ms); return; } /* We are using timer 0 */ TSTR &= ~0x01; /* Stop the timer */ TSNC &= ~0x01; /* No synchronization */ TMDR &= ~0x01; /* Operate normally */ TCNT0 = 0; /* Start counting at 0 */ GRA0 = (unsigned short)(count - 1); TCR0 = 0x23; /* Clear at GRA match, sysclock/8 */ /* Enable interrupt on level 1 */ IPRC = (IPRC & ~0x00f0) | 0x0010; TSR0 &= ~0x01; TIER0 = 0xf9; /* Enable GRA match interrupt */ TSTR |= 0x01; /* Start timer 1 */ } void IMIA0(void) __attribute__ ((interrupt_handler)); void IMIA0(void) { int i; /* Run through the list of tick tasks */ for(i = 0;i < MAX_NUM_TICK_TASKS;i++) { if(tick_funcs[i]) { tick_funcs[i](); } } current_tick++; TSR0 &= ~0x01; } #elif defined(CPU_COLDFIRE) void tick_start(unsigned int interval_in_ms) { unsigned long count; int prescale; count = CPU_FREQ/2 * interval_in_ms / 1000 / 16; if(count > 0x10000) { panicf("Error! The tick interval is too long (%d ms)\n", interval_in_ms); return; } prescale = cpu_frequency / CPU_FREQ; /* Note: The prescaler is later adjusted on-the-fly on CPU frequency changes within timer.c */ /* We are using timer 0 */ TRR0 = (unsigned short)(count - 1); /* The reference count */ TCN0 = 0; /* reset the timer */ TMR0 = 0x001d | ((unsigned short)(prescale - 1) << 8); /* restart, CLK/16, enabled, prescaler */ TER0 = 0xff; /* Clear all events */ ICR1 = 0x8c; /* Interrupt on level 3.0 */ IMR &= ~0x200; } void TIMER0(void) __attribute__ ((interrupt_handler)); void TIMER0(void) { int i; /* Run through the list of tick tasks */ for(i = 0;i < MAX_NUM_TICK_TASKS;i++) { if(tick_funcs[i]) { tick_funcs[i](); } } current_tick++; TER0 = 0xff; /* Clear all events */ } #elif defined(CPU_PP) #ifndef BOOTLOADER void TIMER1(void) { int i; /* Run through the list of tick tasks (using main core) */ TIMER1_VAL; /* Read value to ack IRQ */ /* Run through the list of tick tasks using main CPU core - wake up the COP through its control interface to provide pulse */ for (i = 0;i < MAX_NUM_TICK_TASKS;i++) { if (tick_funcs[i]) { tick_funcs[i](); } } #if NUM_CORES > 1 /* Pulse the COP */ core_wake(COP); #endif /* NUM_CORES */ current_tick++; } #endif /* Must be last function called init kernel/thread initialization */ void tick_start(unsigned int interval_in_ms) { #ifndef BOOTLOADER TIMER1_CFG = 0x0; TIMER1_VAL; /* enable timer */ TIMER1_CFG = 0xc0000000 | (interval_in_ms*1000 - 1); /* unmask interrupt source */ CPU_INT_EN = TIMER1_MASK; #else /* We don't enable interrupts in the bootloader */ (void)interval_in_ms; #endif } #elif CONFIG_CPU == PNX0101 void timer_handler(void) { int i; /* Run through the list of tick tasks */ for(i = 0;i < MAX_NUM_TICK_TASKS;i++) { if(tick_funcs[i]) tick_funcs[i](); } current_tick++; TIMER0.clr = 0; } void tick_start(unsigned int interval_in_ms) { TIMER0.ctrl &= ~0x80; /* Disable the counter */ TIMER0.ctrl |= 0x40; /* Reload after counting down to zero */ TIMER0.load = 3000000 * interval_in_ms / 1000; TIMER0.ctrl &= ~0xc; /* No prescaler */ TIMER0.clr = 1; /* Clear the interrupt request */ irq_set_int_handler(IRQ_TIMER0, timer_handler); irq_enable_int(IRQ_TIMER0); TIMER0.ctrl |= 0x80; /* Enable the counter */ } #endif int tick_add_task(void (*f)(void)) { int i; int oldlevel = disable_irq_save(); /* Add a task if there is room */ for(i = 0;i < MAX_NUM_TICK_TASKS;i++) { if(tick_funcs[i] == NULL) { tick_funcs[i] = f; restore_irq(oldlevel); return 0; } } restore_irq(oldlevel); panicf("Error! tick_add_task(): out of tasks"); return -1; } int tick_remove_task(void (*f)(void)) { int i; int oldlevel = disable_irq_save(); /* Remove a task if it is there */ for(i = 0;i < MAX_NUM_TICK_TASKS;i++) { if(tick_funcs[i] == f) { tick_funcs[i] = NULL; restore_irq(oldlevel); return 0; } } restore_irq(oldlevel); return -1; } /**************************************************************************** * Tick-based interval timers/one-shots - be mindful this is not really * intended for continuous timers but for events that need to run for a short * time and be cancelled without further software intervention. ****************************************************************************/ #ifdef INCLUDE_TIMEOUT_API static struct timeout *tmo_list = NULL; /* list of active timeout events */ /* timeout tick task - calls event handlers when they expire * Event handlers may alter ticks, callback and data during operation. */ static void timeout_tick(void) { unsigned long tick = current_tick; struct timeout *curr, *next; for (curr = tmo_list; curr != NULL; curr = next) { next = (struct timeout *)curr->next; if (TIME_BEFORE(tick, curr->expires)) continue; /* this event has expired - call callback */ if (curr->callback(curr)) *(long *)&curr->expires = tick + curr->ticks; /* reload */ else timeout_cancel(curr); /* cancel */ } } /* Cancels a timeout callback - can be called from the ISR */ void timeout_cancel(struct timeout *tmo) { int oldlevel = disable_irq_save(); if (tmo_list != NULL) { struct timeout *curr = tmo_list; struct timeout *prev = NULL; while (curr != tmo && curr != NULL) { prev = curr; curr = (struct timeout *)curr->next; } if (curr != NULL) { /* in list */ if (prev == NULL) tmo_list = (struct timeout *)curr->next; else *(const struct timeout **)&prev->next = curr->next; if (tmo_list == NULL) tick_remove_task(timeout_tick); /* last one - remove task */ } /* not in list or tmo == NULL */ } restore_irq(oldlevel); } /* Adds a timeout callback - calling with an active timeout resets the interval - can be called from the ISR */ void timeout_register(struct timeout *tmo, timeout_cb_type callback, int ticks, intptr_t data) { int oldlevel; struct timeout *curr; if (tmo == NULL) return; oldlevel = disable_irq_save(); /* see if this one is already registered */ curr = tmo_list; while (curr != tmo && curr != NULL) curr = (struct timeout *)curr->next; if (curr == NULL) { /* not found - add it */ if (tmo_list == NULL) tick_add_task(timeout_tick); /* first one - add task */ *(struct timeout **)&tmo->next = tmo_list; tmo_list = tmo; } tmo->callback = callback; tmo->ticks = ticks; tmo->data = data; *(long *)&tmo->expires = current_tick + ticks; restore_irq(oldlevel); } #endif /* INCLUDE_TIMEOUT_API */ /**************************************************************************** * Thread stuff ****************************************************************************/ void sleep(int ticks) { #if CONFIG_CPU == S3C2440 && defined(BOOTLOADER) volatile int counter; TCON &= ~(1 << 20); // stop timer 4 // TODO: this constant depends on dividers settings inherited from // firmware. Set them explicitly somwhere. TCNTB4 = 12193 * ticks / HZ; TCON |= 1 << 21; // set manual bit TCON &= ~(1 << 21); // reset manual bit TCON &= ~(1 << 22); //autoreload Off TCON |= (1 << 20); // start timer 4 do { counter = TCNTO4; } while(counter > 0); #elif defined(CPU_PP) && defined(BOOTLOADER) unsigned stop = USEC_TIMER + ticks * (1000000/HZ); while (TIME_BEFORE(USEC_TIMER, stop)) switch_thread(); #else disable_irq(); sleep_thread(ticks); switch_thread(); #endif } void yield(void) { #if ((CONFIG_CPU == S3C2440 || defined(ELIO_TPJ1022)) && defined(BOOTLOADER)) /* Some targets don't like yielding in the bootloader */ #else switch_thread(); #endif } /**************************************************************************** * Queue handling stuff ****************************************************************************/ #ifdef HAVE_EXTENDED_MESSAGING_AND_NAME /**************************************************************************** * Sender thread queue structure that aids implementation of priority * inheritance on queues because the send list structure is the same as * for all other kernel objects: * * Example state: * E0 added with queue_send and removed by thread via queue_wait(_w_tmo) * E3 was posted with queue_post * 4 events remain enqueued (E1-E4) * * rd wr * q->events[]: | XX | E1 | E2 | E3 | E4 | XX | * q->send->senders[]: | NULL | T1 | T2 | NULL | T3 | NULL | * \/ \/ \/ * q->send->list: >->|T0|<->|T1|<->|T2|<-------->|T3|<-< * q->send->curr_sender: /\ * * Thread has E0 in its own struct queue_event. * ****************************************************************************/ /* Puts the specified return value in the waiting thread's return value * and wakes the thread. * * A sender should be confirmed to exist before calling which makes it * more efficent to reject the majority of cases that don't need this * called. */ static void queue_release_sender(struct thread_entry **sender, intptr_t retval) { struct thread_entry *thread = *sender; *sender = NULL; /* Clear slot. */ thread->wakeup_ext_cb = NULL; /* Clear callback. */ thread->retval = retval; /* Assign thread-local return value. */ *thread->bqp = thread; /* Move blocking queue head to thread since wakeup_thread wakes the first thread in the list. */ wakeup_thread(thread->bqp); } /* Releases any waiting threads that are queued with queue_send - * reply with 0. */ static void queue_release_all_senders(struct event_queue *q) { if(q->send) { unsigned int i; for(i = q->read; i != q->write; i++) { struct thread_entry **spp = &q->send->senders[i & QUEUE_LENGTH_MASK]; if(*spp) { queue_release_sender(spp, 0); } } } } /* Callback to do extra forced removal steps from sender list in addition * to the normal blocking queue removal and priority dis-inherit */ static void queue_remove_sender_thread_cb(struct thread_entry *thread) { *((struct thread_entry **)thread->retval) = NULL; thread->wakeup_ext_cb = NULL; thread->retval = 0; } /* Enables queue_send on the specified queue - caller allocates the extra * data structure. Only queues which are taken to be owned by a thread should * enable this however an official owner is not compulsory but must be * specified for priority inheritance to operate. * * Use of queue_wait(_w_tmo) by multiple threads on a queue using synchronous * messages results in an undefined order of message replies. */ void queue_enable_queue_send(struct event_queue *q, struct queue_sender_list *send, struct thread_entry *owner) { int oldlevel = disable_irq_save(); corelock_lock(&q->cl); if(send != NULL && q->send == NULL) { memset(send, 0, sizeof(*send)); #ifdef HAVE_PRIORITY_SCHEDULING send->blocker.wakeup_protocol = wakeup_priority_protocol_release; send->blocker.priority = PRIORITY_IDLE; send->blocker.thread = owner; if(owner != NULL) q->blocker_p = &send->blocker; #endif q->send = send; } corelock_unlock(&q->cl); restore_irq(oldlevel); (void)owner; } /* Unblock a blocked thread at a given event index */ static inline void queue_do_unblock_sender(struct queue_sender_list *send, unsigned int i) { if(send) { struct thread_entry **spp = &send->senders[i]; if(*spp) { queue_release_sender(spp, 0); } } } /* Perform the auto-reply sequence */ static inline void queue_do_auto_reply(struct queue_sender_list *send) { if(send && send->curr_sender) { /* auto-reply */ queue_release_sender(&send->curr_sender, 0); } } /* Moves waiting thread's refrence from the senders array to the * current_sender which represents the thread waiting for a reponse to the * last message removed from the queue. This also protects the thread from * being bumped due to overflow which would not be a valid action since its * message _is_ being processed at this point. */ static inline void queue_do_fetch_sender(struct queue_sender_list *send, unsigned int rd) { if(send) { struct thread_entry **spp = &send->senders[rd]; if(*spp) { /* Move thread reference from array to the next thread that queue_reply will release */ send->curr_sender = *spp; (*spp)->retval = (intptr_t)spp; *spp = NULL; } /* else message was posted asynchronously with queue_post */ } } #else /* Empty macros for when synchoronous sending is not made */ #define queue_release_all_senders(q) #define queue_do_unblock_sender(send, i) #define queue_do_auto_reply(send) #define queue_do_fetch_sender(send, rd) #endif /* HAVE_EXTENDED_MESSAGING_AND_NAME */ /* Queue must not be available for use during this call */ void queue_init(struct event_queue *q, bool register_queue) { int oldlevel = disable_irq_save(); if(register_queue) { corelock_lock(&all_queues.cl); } corelock_init(&q->cl); q->queue = NULL; q->read = 0; q->write = 0; #ifdef HAVE_EXTENDED_MESSAGING_AND_NAME q->send = NULL; /* No message sending by default */ IF_PRIO( q->blocker_p = NULL; ) #endif if(register_queue) { if(all_queues.count >= MAX_NUM_QUEUES) { panicf("queue_init->out of queues"); } /* Add it to the all_queues array */ all_queues.queues[all_queues.count++] = q; corelock_unlock(&all_queues.cl); } restore_irq(oldlevel); } /* Queue must not be available for use during this call */ void queue_delete(struct event_queue *q) { int oldlevel; int i; oldlevel = disable_irq_save(); corelock_lock(&all_queues.cl); corelock_lock(&q->cl); /* Find the queue to be deleted */ for(i = 0;i < all_queues.count;i++) { if(all_queues.queues[i] == q) { /* Move the following queues up in the list */ all_queues.count--; for(;i < all_queues.count;i++) { all_queues.queues[i] = all_queues.queues[i+1]; } break; } } corelock_unlock(&all_queues.cl); /* Release thread(s) waiting on queue head */ thread_queue_wake(&q->queue); #ifdef HAVE_EXTENDED_MESSAGING_AND_NAME if(q->send) { /* Release threads waiting for replies */ queue_release_all_senders(q); /* Reply to any dequeued message waiting for one */ queue_do_auto_reply(q->send); q->send = NULL; IF_PRIO( q->blocker_p = NULL; ) } #endif q->read = 0; q->write = 0; corelock_unlock(&q->cl); restore_irq(oldlevel); } /* NOTE: multiple threads waiting on a queue head cannot have a well- defined release order if timeouts are used. If multiple threads must access the queue head, use a dispatcher or queue_wait only. */ void queue_wait(struct event_queue *q, struct queue_event *ev) { int oldlevel; unsigned int rd; #ifdef HAVE_PRIORITY_SCHEDULING KERNEL_ASSERT(QUEUE_GET_THREAD(q) == NULL || QUEUE_GET_THREAD(q) == thread_get_current(), "queue_wait->wrong thread\n"); #endif oldlevel = disable_irq_save(); corelock_lock(&q->cl); /* auto-reply */ queue_do_auto_reply(q->send); if (q->read == q->write) { struct thread_entry *current = cores[CURRENT_CORE].running; do { IF_COP( current->obj_cl = &q->cl; ) current->bqp = &q->queue; block_thread(current); corelock_unlock(&q->cl); switch_thread(); oldlevel = disable_irq_save(); corelock_lock(&q->cl); } /* A message that woke us could now be gone */ while (q->read == q->write); } rd = q->read++ & QUEUE_LENGTH_MASK; *ev = q->events[rd]; /* Get data for a waiting thread if one */ queue_do_fetch_sender(q->send, rd); corelock_unlock(&q->cl); restore_irq(oldlevel); } void queue_wait_w_tmo(struct event_queue *q, struct queue_event *ev, int ticks) { int oldlevel; #ifdef HAVE_EXTENDED_MESSAGING_AND_NAME KERNEL_ASSERT(QUEUE_GET_THREAD(q) == NULL || QUEUE_GET_THREAD(q) == thread_get_current(), "queue_wait_w_tmo->wrong thread\n"); #endif oldlevel = disable_irq_save(); corelock_lock(&q->cl); /* Auto-reply */ queue_do_auto_reply(q->send); if (q->read == q->write && ticks > 0) { struct thread_entry *current = cores[CURRENT_CORE].running; IF_COP( current->obj_cl = &q->cl; ) current->bqp = &q->queue; block_thread_w_tmo(current, ticks); corelock_unlock(&q->cl); switch_thread(); oldlevel = disable_irq_save(); corelock_lock(&q->cl); } /* no worry about a removed message here - status is checked inside locks - perhaps verify if timeout or false alarm */ if (q->read != q->write) { unsigned int rd = q->read++ & QUEUE_LENGTH_MASK; *ev = q->events[rd]; /* Get data for a waiting thread if one */ queue_do_fetch_sender(q->send, rd); } else { ev->id = SYS_TIMEOUT; } corelock_unlock(&q->cl); restore_irq(oldlevel); } void queue_post(struct event_queue *q, long id, intptr_t data) { int oldlevel; unsigned int wr; oldlevel = disable_irq_save(); corelock_lock(&q->cl); wr = q->write++ & QUEUE_LENGTH_MASK; q->events[wr].id = id; q->events[wr].data = data; /* overflow protect - unblock any thread waiting at this index */ queue_do_unblock_sender(q->send, wr); /* Wakeup a waiting thread if any */ wakeup_thread(&q->queue); corelock_unlock(&q->cl); restore_irq(oldlevel); } #ifdef HAVE_EXTENDED_MESSAGING_AND_NAME /* IRQ handlers are not allowed use of this function - we only aim to protect the queue integrity by turning them off. */ intptr_t queue_send(struct event_queue *q, long id, intptr_t data) { int oldlevel; unsigned int wr; oldlevel = disable_irq_save(); corelock_lock(&q->cl); wr = q->write++ & QUEUE_LENGTH_MASK; q->events[wr].id = id; q->events[wr].data = data; if(q->send) { struct queue_sender_list *send = q->send; struct thread_entry **spp = &send->senders[wr]; struct thread_entry *current = cores[CURRENT_CORE].running; if(*spp) { /* overflow protect - unblock any thread waiting at this index */ queue_release_sender(spp, 0); } /* Wakeup a waiting thread if any */ wakeup_thread(&q->queue); /* Save thread in slot, add to list and wait for reply */ *spp = current; IF_COP( current->obj_cl = &q->cl; ) IF_PRIO( current->blocker = q->blocker_p; ) current->wakeup_ext_cb = queue_remove_sender_thread_cb; current->retval = (intptr_t)spp; current->bqp = &send->list; block_thread(current); corelock_unlock(&q->cl); switch_thread(); return current->retval; } /* Function as queue_post if sending is not enabled */ wakeup_thread(&q->queue); corelock_unlock(&q->cl); restore_irq(oldlevel); return 0; } #if 0 /* not used now but probably will be later */ /* Query if the last message dequeued was added by queue_send or not */ bool queue_in_queue_send(struct event_queue *q) { bool in_send; #if NUM_CORES > 1 int oldlevel = disable_irq_save(); corelock_lock(&q->cl); #endif in_send = q->send && q->send->curr_sender; #if NUM_CORES > 1 corelock_unlock(&q->cl); restore_irq(oldlevel); #endif return in_send; } #endif /* Replies with retval to the last dequeued message sent with queue_send */ void queue_reply(struct event_queue *q, intptr_t retval) { if(q->send && q->send->curr_sender) { int oldlevel = disable_irq_save(); corelock_lock(&q->cl); /* Double-check locking */ IF_COP( if(q->send && q->send->curr_sender) ) { queue_release_sender(&q->send->curr_sender, retval); } corelock_unlock(&q->cl); restore_irq(oldlevel); } } bool queue_peek(struct event_queue *q, struct queue_event *ev) { if(q->read == q->write) return false; bool have_msg = false; int oldlevel = disable_irq_save(); corelock_lock(&q->cl); if(q->read != q->write) { *ev = q->events[q->read & QUEUE_LENGTH_MASK]; have_msg = true; } corelock_unlock(&q->cl); restore_irq(oldlevel); return have_msg; } #endif /* HAVE_EXTENDED_MESSAGING_AND_NAME */ /* Poll queue to see if a message exists - careful in using the result if * queue_remove_from_head is called when messages are posted - possibly use * queue_wait_w_tmo(&q, 0) in that case or else a removed message that * unsignals the queue may cause an unwanted block */ bool queue_empty(const struct event_queue* q) { return ( q->read == q->write ); } void queue_clear(struct event_queue* q) { int oldlevel; oldlevel = disable_irq_save(); corelock_lock(&q->cl); /* Release all threads waiting in the queue for a reply - dequeued sent message will be handled by owning thread */ queue_release_all_senders(q); q->read = 0; q->write = 0; corelock_unlock(&q->cl); restore_irq(oldlevel); } void queue_remove_from_head(struct event_queue *q, long id) { int oldlevel; oldlevel = disable_irq_save(); corelock_lock(&q->cl); while(q->read != q->write) { unsigned int rd = q->read & QUEUE_LENGTH_MASK; if(q->events[rd].id != id) { break; } /* Release any thread waiting on this message */ queue_do_unblock_sender(q->send, rd); q->read++; } corelock_unlock(&q->cl); restore_irq(oldlevel); } /** * The number of events waiting in the queue. * * @param struct of event_queue * @return number of events in the queue */ int queue_count(const struct event_queue *q) { return q->write - q->read; } int queue_broadcast(long id, intptr_t data) { int i; #if NUM_CORES > 1 int oldlevel = disable_irq_save(); corelock_lock(&all_queues.cl); #endif for(i = 0;i < all_queues.count;i++) { queue_post(all_queues.queues[i], id, data); } #if NUM_CORES > 1 corelock_unlock(&all_queues.cl); restore_irq(oldlevel); #endif return i; } /**************************************************************************** * Simple mutex functions ;) ****************************************************************************/ /* Initialize a mutex object - call before any use and do not call again once * the object is available to other threads */ void mutex_init(struct mutex *m) { corelock_init(&m->cl); m->queue = NULL; m->count = 0; m->locked = 0; MUTEX_SET_THREAD(m, NULL); #ifdef HAVE_PRIORITY_SCHEDULING m->blocker.priority = PRIORITY_IDLE; m->blocker.wakeup_protocol = wakeup_priority_protocol_transfer; m->no_preempt = false; #endif } /* Gain ownership of a mutex object or block until it becomes free */ void mutex_lock(struct mutex *m) { const unsigned int core = CURRENT_CORE; struct thread_entry *current = cores[core].running; if(current == MUTEX_GET_THREAD(m)) { /* current thread already owns this mutex */ m->count++; return; } /* lock out other cores */ corelock_lock(&m->cl); if(m->locked == 0) { /* lock is open */ MUTEX_SET_THREAD(m, current); m->locked = 1; corelock_unlock(&m->cl); return; } /* block until the lock is open... */ IF_COP( current->obj_cl = &m->cl; ) IF_PRIO( current->blocker = &m->blocker; ) current->bqp = &m->queue; disable_irq(); block_thread(current); corelock_unlock(&m->cl); /* ...and turn control over to next thread */ switch_thread(); } /* Release ownership of a mutex object - only owning thread must call this */ void mutex_unlock(struct mutex *m) { /* unlocker not being the owner is an unlocking violation */ KERNEL_ASSERT(MUTEX_GET_THREAD(m) == thread_get_current(), "mutex_unlock->wrong thread (%s != %s)\n", MUTEX_GET_THREAD(m)->name, thread_get_current()->name); if(m->count > 0) { /* this thread still owns lock */ m->count--; return; } /* lock out other cores */ corelock_lock(&m->cl); /* transfer to next queued thread if any */ if(m->queue == NULL) { /* no threads waiting - open the lock */ MUTEX_SET_THREAD(m, NULL); m->locked = 0; corelock_unlock(&m->cl); return; } else { const int oldlevel = disable_irq_save(); /* Tranfer of owning thread is handled in the wakeup protocol * if priorities are enabled otherwise just set it from the * queue head. */ IFN_PRIO( MUTEX_SET_THREAD(m, m->queue); ) IF_PRIO( unsigned int result = ) wakeup_thread(&m->queue); restore_irq(oldlevel); corelock_unlock(&m->cl); #ifdef HAVE_PRIORITY_SCHEDULING if((result & THREAD_SWITCH) && !m->no_preempt) switch_thread(); #endif } } /**************************************************************************** * Simpl-er mutex functions ;) ****************************************************************************/ #if NUM_CORES > 1 void spinlock_init(struct spinlock *l) { corelock_init(&l->cl); l->thread = NULL; l->count = 0; } void spinlock_lock(struct spinlock *l) { const unsigned int core = CURRENT_CORE; struct thread_entry *current = cores[core].running; if(l->thread == current) { /* current core already owns it */ l->count++; return; } /* lock against other processor cores */ corelock_lock(&l->cl); /* take ownership */ l->thread = current; } void spinlock_unlock(struct spinlock *l) { /* unlocker not being the owner is an unlocking violation */ KERNEL_ASSERT(l->thread == thread_get_current(), "spinlock_unlock->wrong thread\n"); if(l->count > 0) { /* this core still owns lock */ l->count--; return; } /* clear owner */ l->thread = NULL; /* release lock */ corelock_unlock(&l->cl); } #endif /* NUM_CORES > 1 */ /**************************************************************************** * Simple semaphore functions ;) ****************************************************************************/ #ifdef HAVE_SEMAPHORE_OBJECTS void semaphore_init(struct semaphore *s, int max, int start) { KERNEL_ASSERT(max > 0 && start >= 0 && start <= max, "semaphore_init->inv arg\n"); s->queue = NULL; s->max = max; s->count = start; corelock_init(&s->cl); } void semaphore_wait(struct semaphore *s) { struct thread_entry *current; corelock_lock(&s->cl); if(--s->count >= 0) { /* wait satisfied */ corelock_unlock(&s->cl); return; } /* too many waits - block until dequeued... */ current = cores[CURRENT_CORE].running; IF_COP( current->obj_cl = &s->cl; ) current->bqp = &s->queue; disable_irq(); block_thread(current); corelock_unlock(&s->cl); /* ...and turn control over to next thread */ switch_thread(); } void semaphore_release(struct semaphore *s) { IF_PRIO( unsigned int result = THREAD_NONE; ) corelock_lock(&s->cl); if(s->count < s->max && ++s->count <= 0) { /* there should be threads in this queue */ KERNEL_ASSERT(s->queue != NULL, "semaphore->wakeup\n"); /* a thread was queued - wake it up */ int oldlevel = disable_irq_save(); IF_PRIO( result = ) wakeup_thread(&s->queue); restore_irq(oldlevel); } corelock_unlock(&s->cl); #ifdef HAVE_PRIORITY_SCHEDULING if(result & THREAD_SWITCH) switch_thread(); #endif } #endif /* HAVE_SEMAPHORE_OBJECTS */ /**************************************************************************** * Simple event functions ;) ****************************************************************************/ #ifdef HAVE_EVENT_OBJECTS void event_init(struct event *e, unsigned int flags) { e->queues[STATE_NONSIGNALED] = NULL; e->queues[STATE_SIGNALED] = NULL; e->state = flags & STATE_SIGNALED; e->automatic = (flags & EVENT_AUTOMATIC) ? 1 : 0; corelock_init(&e->cl); } void event_wait(struct event *e, unsigned int for_state) { struct thread_entry *current; corelock_lock(&e->cl); if(e->automatic != 0) { /* wait for false always satisfied by definition or if it just changed to false */ if(e->state == STATE_SIGNALED || for_state == STATE_NONSIGNALED) { /* automatic - unsignal */ e->state = STATE_NONSIGNALED; corelock_unlock(&e->cl); return; } /* block until state matches */ } else if(for_state == e->state) { /* the state being waited for is the current state */ corelock_unlock(&e->cl); return; } /* block until state matches what callers requests */ current = cores[CURRENT_CORE].running; IF_COP( current->obj_cl = &e->cl; ) current->bqp = &e->queues[for_state]; disable_irq(); block_thread(current); corelock_unlock(&e->cl); /* turn control over to next thread */ switch_thread(); } void event_set_state(struct event *e, unsigned int state) { unsigned int result; int oldlevel; corelock_lock(&e->cl); if(e->state == state) { /* no change */ corelock_unlock(&e->cl); return; } IF_PRIO( result = THREAD_OK; ) oldlevel = disable_irq_save(); if(state == STATE_SIGNALED) { if(e->automatic != 0) { /* no thread should have ever blocked for nonsignaled */ KERNEL_ASSERT(e->queues[STATE_NONSIGNALED] == NULL, "set_event_state->queue[NS]:S\n"); /* pass to next thread and keep unsignaled - "pulse" */ result = wakeup_thread(&e->queues[STATE_SIGNALED]); e->state = (result & THREAD_OK) ? STATE_NONSIGNALED : STATE_SIGNALED; } else { /* release all threads waiting for signaled */ e->state = STATE_SIGNALED; IF_PRIO( result = ) thread_queue_wake(&e->queues[STATE_SIGNALED]); } } else { /* release all threads waiting for nonsignaled */ /* no thread should have ever blocked if automatic */ KERNEL_ASSERT(e->queues[STATE_NONSIGNALED] == NULL || e->automatic == 0, "set_event_state->queue[NS]:NS\n"); e->state = STATE_NONSIGNALED; IF_PRIO( result = ) thread_queue_wake(&e->queues[STATE_NONSIGNALED]); } restore_irq(oldlevel); corelock_unlock(&e->cl); #ifdef HAVE_PRIORITY_SCHEDULING if(result & THREAD_SWITCH) switch_thread(); #endif } #endif /* HAVE_EVENT_OBJECTS */ #ifdef HAVE_WAKEUP_OBJECTS /**************************************************************************** * Lightweight IRQ-compatible wakeup object */ /* Initialize the wakeup object */ void wakeup_init(struct wakeup *w) { w->queue = NULL; w->signalled = 0; IF_COP( corelock_init(&w->cl); ) } /* Wait for a signal blocking indefinitely or for a specified period */ int wakeup_wait(struct wakeup *w, int timeout) { int ret = OBJ_WAIT_SUCCEEDED; /* Presume success */ int oldlevel = disable_irq_save(); corelock_lock(&w->cl); if(w->signalled == 0 && timeout != TIMEOUT_NOBLOCK) { struct thread_entry * current = cores[CURRENT_CORE].running; IF_COP( current->obj_cl = &w->cl; ) current->bqp = &w->queue; if (timeout != TIMEOUT_BLOCK) block_thread_w_tmo(current, timeout); else block_thread(current); corelock_unlock(&w->cl); switch_thread(); oldlevel = disable_irq_save(); corelock_lock(&w->cl); } if(w->signalled == 0) { /* Timed-out or failed */ ret = (timeout != TIMEOUT_BLOCK) ? OBJ_WAIT_TIMEDOUT : OBJ_WAIT_FAILED; } w->signalled = 0; /* Reset */ corelock_unlock(&w->cl); restore_irq(oldlevel); return ret; } /* Signal the thread waiting or leave the signal if the thread hasn't * waited yet. * * returns THREAD_NONE or THREAD_OK */ int wakeup_signal(struct wakeup *w) { int oldlevel = disable_irq_save(); int ret; corelock_lock(&w->cl); w->signalled = 1; ret = wakeup_thread(&w->queue); corelock_unlock(&w->cl); restore_irq(oldlevel); return ret; } #endif /* HAVE_WAKEUP_OBJECTS */