/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2002 by Ulf Ralberg * * 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. * ****************************************************************************/ #ifndef THREAD_H #define THREAD_H #include "config.h" #include #include #include /* Priority scheduling (when enabled with HAVE_PRIORITY_SCHEDULING) works * by giving high priority threads more CPU time than less priority threads * when they need it. Priority is differential such that the priority * difference between a lower priority runnable thread and the highest priority * runnable thread determines the amount of aging nescessary for the lower * priority thread to be scheduled in order to prevent starvation. * * If software playback codec pcm buffer is going down to critical, codec * can gradually raise its own priority to override user interface and * prevent playback skipping. */ #define PRIORITY_RESERVED_HIGH 0 /* Reserved */ #define PRIORITY_RESERVED_LOW 32 /* Reserved */ #define HIGHEST_PRIORITY 1 /* The highest possible thread priority */ #define LOWEST_PRIORITY 31 /* The lowest possible thread priority */ /* Realtime range reserved for threads that will not allow threads of lower * priority to age and run (future expansion) */ #define PRIORITY_REALTIME_1 1 #define PRIORITY_REALTIME_2 2 #define PRIORITY_REALTIME_3 3 #define PRIORITY_REALTIME_4 4 #define PRIORITY_REALTIME 4 /* Lowest realtime range */ #define PRIORITY_BUFFERING 15 /* Codec buffering thread */ #define PRIORITY_USER_INTERFACE 16 /* The main thread */ #define PRIORITY_RECORDING 16 /* Recording thread */ #define PRIORITY_PLAYBACK 16 /* Variable between this and MAX */ #define PRIORITY_PLAYBACK_MAX 5 /* Maximum allowable playback priority */ #define PRIORITY_SYSTEM 18 /* All other firmware threads */ #define PRIORITY_BACKGROUND 20 /* Normal application threads */ #define NUM_PRIORITIES 32 #define PRIORITY_IDLE 32 /* Priority representative of no tasks */ /* TODO: Only a minor tweak to create_thread would be needed to let * thread slots be caller allocated - no essential threading functionality * depends upon an array */ #if CONFIG_CODEC == SWCODEC #ifdef HAVE_RECORDING #define MAXTHREADS 18 #else #define MAXTHREADS 17 #endif #else #define MAXTHREADS 11 #endif /* CONFIG_CODE == * */ #define DEFAULT_STACK_SIZE 0x400 /* Bytes */ #ifndef SIMULATOR /* Need to keep structures inside the header file because debug_menu * needs them. */ #ifdef CPU_COLDFIRE struct regs { uint32_t macsr; /* 0 - EMAC status register */ uint32_t d[6]; /* 4-24 - d2-d7 */ uint32_t a[5]; /* 28-44 - a2-a6 */ uint32_t sp; /* 48 - Stack pointer (a7) */ uint32_t start; /* 52 - Thread start address, or NULL when started */ }; #elif CONFIG_CPU == SH7034 struct regs { uint32_t r[7]; /* 0-24 - Registers r8 thru r14 */ uint32_t sp; /* 28 - Stack pointer (r15) */ uint32_t pr; /* 32 - Procedure register */ uint32_t start; /* 36 - Thread start address, or NULL when started */ }; #elif defined(CPU_ARM) struct regs { uint32_t r[8]; /* 0-28 - Registers r4-r11 */ uint32_t sp; /* 32 - Stack pointer (r13) */ uint32_t lr; /* 36 - r14 (lr) */ uint32_t start; /* 40 - Thread start address, or NULL when started */ }; #endif /* CONFIG_CPU */ #else struct regs { void *t; /* Simulator OS thread */ void *s; /* Semaphore for blocking and wakeup */ void (*start)(void); /* Start function */ }; #endif /* !SIMULATOR */ /* NOTE: The use of the word "queue" may also refer to a linked list of threads being maintainted that are normally dealt with in FIFO order and not nescessarily kernel event_queue */ enum { /* States without a timeout must be first */ STATE_KILLED = 0, /* Thread is killed (default) */ STATE_RUNNING, /* Thread is currently running */ STATE_BLOCKED, /* Thread is indefinitely blocked on a queue */ /* These states involve adding the thread to the tmo list */ STATE_SLEEPING, /* Thread is sleeping with a timeout */ STATE_BLOCKED_W_TMO, /* Thread is blocked on a queue with a timeout */ /* Miscellaneous states */ STATE_FROZEN, /* Thread is suspended and will not run until thread_thaw is called with its ID */ THREAD_NUM_STATES, TIMEOUT_STATE_FIRST = STATE_SLEEPING, }; #if NUM_CORES > 1 /* Pointer value for name field to indicate thread is being killed. Using * an alternate STATE_* won't work since that would interfere with operation * while the thread is still running. */ #define THREAD_DESTRUCT ((const char *)~(intptr_t)0) #endif /* Link information for lists thread is in */ struct thread_entry; /* forward */ struct thread_list { struct thread_entry *prev; /* Previous thread in a list */ struct thread_entry *next; /* Next thread in a list */ }; /* Small objects for core-wise mutual exclusion */ #if CONFIG_CORELOCK == SW_CORELOCK /* No reliable atomic instruction available - use Peterson's algorithm */ struct corelock { volatile unsigned char myl[NUM_CORES]; volatile unsigned char turn; } __attribute__((packed)); void corelock_init(struct corelock *cl); void corelock_lock(struct corelock *cl); int corelock_try_lock(struct corelock *cl); void corelock_unlock(struct corelock *cl); #elif CONFIG_CORELOCK == CORELOCK_SWAP /* Use native atomic swap/exchange instruction */ struct corelock { volatile unsigned char locked; } __attribute__((packed)); #define corelock_init(cl) \ ({ (cl)->locked = 0; }) #define corelock_lock(cl) \ ({ while (test_and_set(&(cl)->locked, 1)); }) #define corelock_try_lock(cl) \ ({ test_and_set(&(cl)->locked, 1) ? 0 : 1; }) #define corelock_unlock(cl) \ ({ (cl)->locked = 0; }) #else /* No atomic corelock op needed or just none defined */ #define corelock_init(cl) #define corelock_lock(cl) #define corelock_try_lock(cl) #define corelock_unlock(cl) #endif /* core locking selection */ #ifdef HAVE_PRIORITY_SCHEDULING struct blocker { struct thread_entry *thread; /* thread blocking other threads (aka. object owner) */ int priority; /* highest priority waiter */ struct thread_entry * (*wakeup_protocol)(struct thread_entry *thread); }; /* Choices of wakeup protocol */ /* For transfer of object ownership by one thread to another thread by * the owning thread itself (mutexes) */ struct thread_entry * wakeup_priority_protocol_transfer(struct thread_entry *thread); /* For release by owner where ownership doesn't change - other threads, * interrupts, timeouts, etc. (mutex timeout, queues) */ struct thread_entry * wakeup_priority_protocol_release(struct thread_entry *thread); struct priority_distribution { uint8_t hist[NUM_PRIORITIES]; /* Histogram: Frequency for each priority */ uint32_t mask; /* Bitmask of hist entries that are not zero */ }; #endif /* HAVE_PRIORITY_SCHEDULING */ /* Information kept in each thread slot * members are arranged according to size - largest first - in order * to ensure both alignment and packing at the same time. */ struct thread_entry { struct regs context; /* Register context at switch - _must_ be first member */ uintptr_t *stack; /* Pointer to top of stack */ const char *name; /* Thread name */ long tmo_tick; /* Tick when thread should be woken from timeout - states: STATE_SLEEPING/STATE_BLOCKED_W_TMO */ struct thread_list l; /* Links for blocked/waking/running - circular linkage in both directions */ struct thread_list tmo; /* Links for timeout list - Circular in reverse direction, NULL-terminated in forward direction - states: STATE_SLEEPING/STATE_BLOCKED_W_TMO */ struct thread_entry **bqp; /* Pointer to list variable in kernel object where thread is blocked - used for implicit unblock and explicit wake states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */ #if NUM_CORES > 1 struct corelock *obj_cl; /* Object corelock where thead is blocked - states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */ #endif struct thread_entry *queue; /* List of threads waiting for thread to be removed */ #ifdef HAVE_EXTENDED_MESSAGING_AND_NAME #define HAVE_WAKEUP_EXT_CB void (*wakeup_ext_cb)(struct thread_entry *thread); /* Callback that performs special steps needed when being forced off of an object's wait queue that go beyond the standard wait queue removal and priority disinheritance */ /* Only enabled when using queue_send for now */ #endif #if defined(HAVE_EXTENDED_MESSAGING_AND_NAME) || NUM_CORES > 1 intptr_t retval; /* Return value from a blocked operation/ misc. use */ #endif #ifdef HAVE_PRIORITY_SCHEDULING /* Priority summary of owned objects that support inheritance */ struct blocker *blocker; /* Pointer to blocker when this thread is blocked on an object that supports PIP - states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */ struct priority_distribution pdist; /* Priority summary of owned objects that have blocked threads and thread's own base priority */ int skip_count; /* Number of times skipped if higher priority thread was running */ #endif unsigned short stack_size; /* Size of stack in bytes */ #ifdef HAVE_PRIORITY_SCHEDULING unsigned char base_priority; /* Base priority (set explicitly during creation or thread_set_priority) */ unsigned char priority; /* Scheduled priority (higher of base or all threads blocked by this one) */ #endif unsigned char state; /* Thread slot state (STATE_*) */ #ifdef HAVE_SCHEDULER_BOOSTCTRL unsigned char cpu_boost; /* CPU frequency boost flag */ #endif #if NUM_CORES > 1 unsigned char core; /* The core to which thread belongs */ struct corelock waiter_cl; /* Corelock for thread_wait */ struct corelock slot_cl; /* Corelock to lock thread slot */ #endif }; #if NUM_CORES > 1 /* Operations to be performed just before stopping a thread and starting a new one if specified before calling switch_thread */ enum { TBOP_CLEAR = 0, /* No operation to do */ TBOP_UNLOCK_CORELOCK, /* Unlock a corelock variable */ TBOP_SWITCH_CORE, /* Call the core switch preparation routine */ }; struct thread_blk_ops { struct corelock *cl_p; /* pointer to corelock */ unsigned char flags; /* TBOP_* flags */ }; #endif /* NUM_CORES > 1 */ /* Information kept for each core * Member are arranged for the same reason as in thread_entry */ struct core_entry { /* "Active" lists - core is constantly active on these and are never locked and interrupts do not access them */ struct thread_entry *running; /* threads that are running (RTR) */ struct thread_entry *timeout; /* threads that are on a timeout before running again */ struct thread_entry *block_task; /* Task going off running list */ #ifdef HAVE_PRIORITY_SCHEDULING struct priority_distribution rtr; /* Summary of running and ready-to-run threads */ #endif long next_tmo_check; /* soonest time to check tmo threads */ #if NUM_CORES > 1 struct thread_blk_ops blk_ops; /* operations to perform when blocking a thread */ #ifdef HAVE_PRIORITY_SCHEDULING struct corelock rtr_cl; /* Lock for rtr list */ #endif #endif /* NUM_CORES */ }; #ifdef HAVE_PRIORITY_SCHEDULING #define IF_PRIO(...) __VA_ARGS__ #define IFN_PRIO(...) #else #define IF_PRIO(...) #define IFN_PRIO(...) __VA_ARGS__ #endif /* Macros generate better code than an inline function is this case */ #if (defined (CPU_PP) || defined (CPU_ARM)) /* atomic */ #if CONFIG_CORELOCK == SW_CORELOCK #define test_and_set(a, v, cl) \ xchg8((a), (v), (cl)) /* atomic */ #define xchg8(a, v, cl) \ ({ uint32_t o; \ corelock_lock(cl); \ o = *(uint8_t *)(a); \ *(uint8_t *)(a) = (v); \ corelock_unlock(cl); \ o; }) #define xchg32(a, v, cl) \ ({ uint32_t o; \ corelock_lock(cl); \ o = *(uint32_t *)(a); \ *(uint32_t *)(a) = (v); \ corelock_unlock(cl); \ o; }) #define xchgptr(a, v, cl) \ ({ typeof (*(a)) o; \ corelock_lock(cl); \ o = *(a); \ *(a) = (v); \ corelock_unlock(cl); \ o; }) #elif CONFIG_CORELOCK == CORELOCK_SWAP /* atomic */ #define test_and_set(a, v, ...) \ xchg8((a), (v)) #define xchg8(a, v, ...) \ ({ uint32_t o; \ asm volatile( \ "swpb %0, %1, [%2]" \ : "=&r"(o) \ : "r"(v), \ "r"((uint8_t*)(a))); \ o; }) /* atomic */ #define xchg32(a, v, ...) \ ({ uint32_t o; \ asm volatile( \ "swp %0, %1, [%2]" \ : "=&r"(o) \ : "r"((uint32_t)(v)), \ "r"((uint32_t*)(a))); \ o; }) /* atomic */ #define xchgptr(a, v, ...) \ ({ typeof (*(a)) o; \ asm volatile( \ "swp %0, %1, [%2]" \ : "=&r"(o) \ : "r"(v), "r"(a)); \ o; }) #endif /* locking selection */ #elif defined (CPU_COLDFIRE) /* atomic */ /* one branch will be optimized away if v is a constant expression */ #define test_and_set(a, v, ...) \ ({ uint32_t o = 0; \ if (v) { \ asm volatile ( \ "bset.b #0, (%0)" \ : : "a"((uint8_t*)(a)) \ : "cc"); \ } else { \ asm volatile ( \ "bclr.b #0, (%0)" \ : : "a"((uint8_t*)(a)) \ : "cc"); \ } \ asm volatile ("sne.b %0" \ : "+d"(o)); \ o; }) #elif CONFIG_CPU == SH7034 /* atomic */ #define test_and_set(a, v, ...) \ ({ uint32_t o; \ asm volatile ( \ "tas.b @%2 \n" \ "mov #-1, %0 \n" \ "negc %0, %0 \n" \ : "=r"(o) \ : "M"((uint32_t)(v)), /* Value of_v must be 1 */ \ "r"((uint8_t *)(a))); \ o; }) #endif /* CONFIG_CPU == */ /* defaults for no asm version */ #ifndef test_and_set /* not atomic */ #define test_and_set(a, v, ...) \ ({ uint32_t o = *(uint8_t *)(a); \ *(uint8_t *)(a) = (v); \ o; }) #endif /* test_and_set */ #ifndef xchg8 /* not atomic */ #define xchg8(a, v, ...) \ ({ uint32_t o = *(uint8_t *)(a); \ *(uint8_t *)(a) = (v); \ o; }) #endif /* xchg8 */ #ifndef xchg32 /* not atomic */ #define xchg32(a, v, ...) \ ({ uint32_t o = *(uint32_t *)(a); \ *(uint32_t *)(a) = (v); \ o; }) #endif /* xchg32 */ #ifndef xchgptr /* not atomic */ #define xchgptr(a, v, ...) \ ({ typeof (*(a)) o = *(a); \ *(a) = (v); \ o; }) #endif /* xchgptr */ void core_idle(void); void core_wake(IF_COP_VOID(unsigned int core)); /* Initialize the scheduler */ void init_threads(void); /* Allocate a thread in the scheduler */ #define CREATE_THREAD_FROZEN 0x00000001 /* Thread is frozen at create time */ struct thread_entry* create_thread(void (*function)(void), void* stack, size_t stack_size, unsigned flags, const char *name IF_PRIO(, int priority) IF_COP(, unsigned int core)); /* Set and clear the CPU frequency boost flag for the calling thread */ #ifdef HAVE_SCHEDULER_BOOSTCTRL void trigger_cpu_boost(void); void cancel_cpu_boost(void); #else #define trigger_cpu_boost() #define cancel_cpu_boost() #endif /* Make a frozed thread runnable (when started with CREATE_THREAD_FROZEN). * Has no effect on a thread not frozen. */ void thread_thaw(struct thread_entry *thread); /* Wait for a thread to exit */ void thread_wait(struct thread_entry *thread); /* Exit the current thread */ void thread_exit(void); #if defined(DEBUG) || defined(ROCKBOX_HAS_LOGF) #define ALLOW_REMOVE_THREAD /* Remove a thread from the scheduler */ void remove_thread(struct thread_entry *thread); #endif /* Switch to next runnable thread */ void switch_thread(void); /* Blocks a thread for at least the specified number of ticks (0 = wait until * next tick) */ void sleep_thread(int ticks); /* Indefinitely blocks the current thread on a thread queue */ void block_thread(struct thread_entry *current); /* Blocks the current thread on a thread queue until explicitely woken or * the timeout is reached */ void block_thread_w_tmo(struct thread_entry *current, int timeout); /* Return bit flags for thread wakeup */ #define THREAD_NONE 0x0 /* No thread woken up (exclusive) */ #define THREAD_OK 0x1 /* A thread was woken up */ #define THREAD_SWITCH 0x2 /* Task switch recommended (one or more of higher priority than current were woken) */ /* A convenience function for waking an entire queue of threads. */ unsigned int thread_queue_wake(struct thread_entry **list); /* Wakeup a thread at the head of a list */ unsigned int wakeup_thread(struct thread_entry **list); #ifdef HAVE_PRIORITY_SCHEDULING int thread_set_priority(struct thread_entry *thread, int priority); int thread_get_priority(struct thread_entry *thread); #endif /* HAVE_PRIORITY_SCHEDULING */ #if NUM_CORES > 1 unsigned int switch_core(unsigned int new_core); #endif struct thread_entry * thread_get_current(void); /* Debugging info - only! */ int thread_stack_usage(const struct thread_entry *thread); #if NUM_CORES > 1 int idle_stack_usage(unsigned int core); #endif void thread_get_name(char *buffer, int size, struct thread_entry *thread); #ifdef RB_PROFILE void profile_thread(void); #endif #endif /* THREAD_H */