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|
/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Task scheduling / events module for Chrome EC operating system */
#include "atomic.h"
#include "common.h"
#include "console.h"
#include "cpu.h"
#include "link_defs.h"
#include "panic.h"
#include "task.h"
#include "timer.h"
#include "util.h"
typedef union {
struct {
/*
* Note that sp must be the first element in the task struct
* for __switchto() to work.
*/
uint32_t sp; /* Saved stack pointer for context switch */
uint32_t events; /* Bitmaps of received events */
uint64_t runtime; /* Time spent in task */
uint32_t *stack; /* Start of stack */
};
} task_;
/* Value to store in unused stack */
#define STACK_UNUSED_VALUE 0xdeadd00d
/* declare task routine prototypes */
#define TASK(n, r, d, s) void r(void *);
void __idle(void);
CONFIG_TASK_LIST
CONFIG_TEST_TASK_LIST
CONFIG_CTS_TASK_LIST
#undef TASK
/* Task names for easier debugging */
#define TASK(n, r, d, s) #n,
static const char * const task_names[] = {
"<< idle >>",
CONFIG_TASK_LIST
CONFIG_TEST_TASK_LIST
CONFIG_CTS_TASK_LIST
};
#undef TASK
#ifdef CONFIG_TASK_PROFILING
static uint64_t task_start_time; /* Time task scheduling started */
/*
* We only keep 32-bit values for exception start/end time, to avoid
* accounting errors when we service interrupt when the timer wraps around.
*/
static uint32_t exc_start_time; /* Time of task->exception transition */
static uint32_t exc_end_time; /* Time of exception->task transition */
static uint64_t exc_total_time; /* Total time in exceptions */
static uint32_t svc_calls; /* Number of service calls */
static uint32_t task_switches; /* Number of times active task changed */
static uint32_t irq_dist[CONFIG_IRQ_COUNT]; /* Distribution of IRQ calls */
#endif
extern void __switchto(task_ *from, task_ *to);
extern int __task_start(int *task_stack_ready);
#ifndef CONFIG_LOW_POWER_IDLE
/* Idle task. Executed when no tasks are ready to be scheduled. */
void __idle(void)
{
while (1) {
#ifdef CHIP_NPCX
/*
* Using host access to make sure M4 core clock will
* return when the eSPI accesses the Host modules if
* CSAE bit is set. Please notice this symptom only
* occurs at npcx5.
*/
#if defined(CHIP_FAMILY_NPCX5) && defined(CONFIG_HOSTCMD_ESPI)
/* Enable Host access wakeup */
SET_BIT(NPCX_WKEN(MIWU_TABLE_0, MIWU_GROUP_5), 6);
#endif
/*
* TODO (ML): A interrupt that occurs shortly before entering
* idle mode starts getting services while the Core transitions
* into idle mode. The results in a hard fault when the Core,
* shortly therefore, resumes execution on exiting idle mode.
* Workaround: Replace the idle function with the followings
*/
asm (
"cpsid i\n" /* Disable interrupt */
"push {r0-r5}\n" /* Save needed registers */
"wfi\n" /* Wait for int to enter idle */
"ldm %0, {r0-r5}\n" /* Add a delay after WFI */
"pop {r0-r5}\n" /* Restore regs before enabling ints */
"isb\n" /* Flush the cpu pipeline */
"cpsie i\n" :: "r" (0x100A8000) /* Enable interrupts */
);
#else
/*
* Wait for the next irq event. This stops the CPU clock
* (sleep / deep sleep, depending on chip config).
*/
asm("wfi");
#endif
}
}
#endif /* !CONFIG_LOW_POWER_IDLE */
static void task_exit_trap(void)
{
int i = task_get_current();
cprints(CC_TASK, "Task %d (%s) exited!", i, task_names[i]);
/* Exited tasks simply sleep forever */
while (1)
task_wait_event(-1);
}
/* Startup parameters for all tasks. */
#define TASK(n, r, d, s) { \
.r0 = (uint32_t)d, \
.pc = (uint32_t)r, \
.stack_size = s, \
},
static const struct {
uint32_t r0;
uint32_t pc;
uint16_t stack_size;
} tasks_init[] = {
TASK(IDLE, __idle, 0, IDLE_TASK_STACK_SIZE)
CONFIG_TASK_LIST
CONFIG_TEST_TASK_LIST
CONFIG_CTS_TASK_LIST
};
#undef TASK
/* Contexts for all tasks */
static task_ tasks[TASK_ID_COUNT];
/* Reset constants and state for all tasks */
#define TASK_RESET_SUPPORTED BIT(31)
#define TASK_RESET_LOCK BIT(30)
#define TASK_RESET_STATE_MASK (TASK_RESET_SUPPORTED | TASK_RESET_LOCK)
#define TASK_RESET_WAITERS_MASK ~TASK_RESET_STATE_MASK
#define TASK_RESET_UNSUPPORTED 0
#define TASK_RESET_STATE_LOCKED (TASK_RESET_SUPPORTED | TASK_RESET_LOCK)
#define TASK_RESET_STATE_UNLOCKED TASK_RESET_SUPPORTED
#ifdef CONFIG_TASK_RESET_LIST
#define ENABLE_RESET(n) \
[TASK_ID_##n] = TASK_RESET_SUPPORTED,
static uint32_t task_reset_state[TASK_ID_COUNT] = {
#ifdef CONFIG_TASK_RESET_LIST
CONFIG_TASK_RESET_LIST
#endif
};
#undef ENABLE_RESET
#endif /* CONFIG_TASK_RESET_LIST */
/* Sanity checks about static task invariants */
BUILD_ASSERT(TASK_ID_COUNT <= sizeof(unsigned) * 8);
BUILD_ASSERT(TASK_ID_COUNT < (1 << (sizeof(task_id_t) * 8)));
BUILD_ASSERT((1 << TASK_ID_COUNT) < TASK_RESET_LOCK);
/* Stacks for all tasks */
#define TASK(n, r, d, s) + s
uint8_t task_stacks[0
TASK(IDLE, __idle, 0, IDLE_TASK_STACK_SIZE)
CONFIG_TASK_LIST
CONFIG_TEST_TASK_LIST
CONFIG_CTS_TASK_LIST
] __aligned(8);
#undef TASK
/* Reserve space to discard context on first context switch. */
uint32_t scratchpad[17];
static task_ *current_task = (task_ *)scratchpad;
/*
* Should IRQs chain to svc_handler()? This should be set if either of the
* following is true:
*
* 1) Task scheduling has started, and task profiling is enabled. Task
* profiling does its tracking in svc_handler().
*
* 2) An event was set by an interrupt; this could result in a higher-priority
* task unblocking. After checking for a task switch, svc_handler() will clear
* the flag (unless profiling is also enabled; then the flag remains set).
*/
static int need_resched_or_profiling;
/*
* Bitmap of all tasks ready to be run.
*
* Start off with only the hooks task marked as ready such that all the modules
* can do their init within a task switching context. The hooks task will then
* make a call to enable all tasks.
*/
static uint32_t tasks_ready = (1 << TASK_ID_HOOKS);
/*
* Initially allow only the HOOKS and IDLE task to run, regardless of ready
* status, in order for HOOK_INIT to complete before other tasks.
* task_enable_all_tasks() will open the flood gates.
*/
static uint32_t tasks_enabled = (1 << TASK_ID_HOOKS) | (1 << TASK_ID_IDLE);
static int start_called; /* Has task swapping started */
static inline task_ *__task_id_to_ptr(task_id_t id)
{
return tasks + id;
}
void interrupt_disable(void)
{
asm("cpsid i");
}
void interrupt_enable(void)
{
asm("cpsie i");
}
inline int in_interrupt_context(void)
{
int ret;
asm("mrs %0, ipsr \n" /* read exception number */
"lsl %0, #23 \n":"=r"(ret)); /* exception bits are the 9 LSB */
return ret;
}
static inline int get_interrupt_context(void)
{
int ret;
asm("mrs %0, ipsr \n":"=r"(ret)); /* read exception number */
return ret & 0x1ff; /* exception bits are the 9 LSB */
}
task_id_t task_get_current(void)
{
#ifdef CONFIG_DEBUG_BRINGUP
/* If we haven't done a context switch then our task ID isn't valid */
ASSERT(current_task != (task_ *)scratchpad);
#endif
return current_task - tasks;
}
uint32_t *task_get_event_bitmap(task_id_t tskid)
{
task_ *tsk = __task_id_to_ptr(tskid);
return &tsk->events;
}
int task_start_called(void)
{
return start_called;
}
/**
* Scheduling system call
*/
void svc_handler(int desched, task_id_t resched)
{
task_ *current, *next;
#ifdef CONFIG_TASK_PROFILING
int exc = get_interrupt_context();
uint32_t t;
#endif
/*
* Push the priority to -1 until the return, to avoid being
* interrupted.
*/
asm volatile("cpsid f\n"
"isb\n");
#ifdef CONFIG_TASK_PROFILING
/*
* SVCall isn't triggered via DECLARE_IRQ(), so it needs to track its
* start time explicitly.
*/
if (exc == 0xb) {
exc_start_time = get_time().le.lo;
svc_calls++;
}
#endif
current = current_task;
#ifdef CONFIG_DEBUG_STACK_OVERFLOW
if (*current->stack != STACK_UNUSED_VALUE) {
panic_printf("\n\nStack overflow in %s task!\n",
task_names[current - tasks]);
#ifdef CONFIG_SOFTWARE_PANIC
software_panic(PANIC_SW_STACK_OVERFLOW, current - tasks);
#endif
}
#endif
if (desched && !current->events) {
/*
* Remove our own ready bit (current - tasks is same as
* task_get_current())
*/
tasks_ready &= ~(1 << (current - tasks));
}
ASSERT(resched <= TASK_ID_COUNT);
tasks_ready |= 1 << resched;
ASSERT(tasks_ready & tasks_enabled);
next = __task_id_to_ptr(__fls(tasks_ready & tasks_enabled));
#ifdef CONFIG_TASK_PROFILING
/* Track time in interrupts */
t = get_time().le.lo;
exc_total_time += (t - exc_start_time);
/*
* Bill the current task for time between the end of the last interrupt
* and the start of this one.
*/
current->runtime += (exc_start_time - exc_end_time);
exc_end_time = t;
#else
/*
* Don't chain here from interrupts until the next time an interrupt
* sets an event.
*/
need_resched_or_profiling = 0;
#endif
/* Nothing to do */
if (next == current)
return;
/* Switch to new task */
#ifdef CONFIG_TASK_PROFILING
task_switches++;
#endif
current_task = next;
__switchto(current, next);
}
void __schedule(int desched, int resched)
{
register int p0 asm("r0") = desched;
register int p1 asm("r1") = resched;
asm("svc 0"::"r"(p0),"r"(p1));
}
#ifdef CONFIG_TASK_PROFILING
void __keep task_start_irq_handler(void *excep_return)
{
/*
* Get time before checking depth, in case this handler is
* pre-empted.
*/
uint32_t t = get_time().le.lo;
int irq = get_interrupt_context() - 16;
/*
* Track IRQ distribution. No need for atomic add, because an IRQ
* can't pre-empt itself.
*/
if (irq < ARRAY_SIZE(irq_dist))
irq_dist[irq]++;
/*
* Continue iff a rescheduling event happened or profiling is active,
* and we are not called from another exception (this must match the
* logic for when we chain to svc_handler() below).
*/
if (!need_resched_or_profiling || (((uint32_t)excep_return & 0xf) == 1))
return;
exc_start_time = t;
}
#endif
void __keep task_resched_if_needed(void *excep_return)
{
/*
* Continue iff a rescheduling event happened or profiling is active,
* and we are not called from another exception.
*/
if (!need_resched_or_profiling || (((uint32_t)excep_return & 0xf) == 1))
return;
svc_handler(0, 0);
}
static uint32_t __wait_evt(int timeout_us, task_id_t resched)
{
task_ *tsk = current_task;
task_id_t me = tsk - tasks;
uint32_t evt;
int ret __attribute__((unused));
ASSERT(!in_interrupt_context());
if (timeout_us > 0) {
timestamp_t deadline = get_time();
deadline.val += timeout_us;
ret = timer_arm(deadline, me);
ASSERT(ret == EC_SUCCESS);
}
while (!(evt = atomic_read_clear(&tsk->events))) {
/* Remove ourself and get the next task in the scheduler */
__schedule(1, resched);
resched = TASK_ID_IDLE;
}
if (timeout_us > 0) {
timer_cancel(me);
/* Ensure timer event is clear, we no longer care about it */
atomic_clear(&tsk->events, TASK_EVENT_TIMER);
}
return evt;
}
uint32_t task_set_event(task_id_t tskid, uint32_t event, int wait)
{
task_ *receiver = __task_id_to_ptr(tskid);
ASSERT(receiver);
/* Set the event bit in the receiver message bitmap */
atomic_or(&receiver->events, event);
/* Re-schedule if priorities have changed */
if (in_interrupt_context()) {
/* The receiver might run again */
atomic_or(&tasks_ready, 1 << tskid);
#ifndef CONFIG_TASK_PROFILING
if (start_called)
need_resched_or_profiling = 1;
#endif
} else {
if (wait)
return __wait_evt(-1, tskid);
else
__schedule(0, tskid);
}
return 0;
}
uint32_t task_wait_event(int timeout_us)
{
return __wait_evt(timeout_us, TASK_ID_IDLE);
}
uint32_t task_wait_event_mask(uint32_t event_mask, int timeout_us)
{
uint64_t deadline = get_time().val + timeout_us;
uint32_t events = 0;
int time_remaining_us = timeout_us;
/* Add the timer event to the mask so we can indicate a timeout */
event_mask |= TASK_EVENT_TIMER;
while (!(events & event_mask)) {
/* Collect events to re-post later */
events |= __wait_evt(time_remaining_us, TASK_ID_IDLE);
time_remaining_us = deadline - get_time().val;
if (timeout_us > 0 && time_remaining_us <= 0) {
/* Ensure we return a TIMER event if we timeout */
events |= TASK_EVENT_TIMER;
break;
}
}
/* Re-post any other events collected */
if (events & ~event_mask)
atomic_or(¤t_task->events, events & ~event_mask);
return events & event_mask;
}
void task_enable_all_tasks(void)
{
/* Mark all tasks as ready and able to run. */
tasks_ready = tasks_enabled = (1 << TASK_ID_COUNT) - 1;
/* Reschedule the highest priority task. */
__schedule(0, 0);
}
void task_enable_irq(int irq)
{
CPU_NVIC_EN(irq / 32) = 1 << (irq % 32);
}
void __keep task_disable_irq(int irq)
{
CPU_NVIC_DIS(irq / 32) = 1 << (irq % 32);
}
void task_clear_pending_irq(int irq)
{
CPU_NVIC_UNPEND(irq / 32) = 1 << (irq % 32);
}
void task_trigger_irq(int irq)
{
CPU_NVIC_SWTRIG = irq;
}
static uint32_t init_task_context(task_id_t id)
{
uint32_t *sp;
/* Stack size in words */
uint32_t ssize = tasks_init[id].stack_size / 4;
/*
* Update stack used by first frame: 8 words for the normal
* stack, plus 8 for R4-R11. Even if using FPU, the first frame
* does not store FP regs.
*/
sp = tasks[id].stack + ssize - 16;
tasks[id].sp = (uint32_t)sp;
/* Initial context on stack (see __switchto()) */
sp[8] = tasks_init[id].r0; /* r0 */
sp[13] = (uint32_t)task_exit_trap; /* lr */
sp[14] = tasks_init[id].pc; /* pc */
sp[15] = 0x01000000; /* psr */
/* Fill unused stack; also used to detect stack overflow. */
for (sp = tasks[id].stack; sp < (uint32_t *)tasks[id].sp; sp++)
*sp = STACK_UNUSED_VALUE;
return ssize;
}
#ifdef CONFIG_TASK_RESET_LIST
/*
* Re-initializes a task stack to its initial state, and marks it ready.
* The task reset lock must be held prior to calling this function.
*/
static void do_task_reset(task_id_t id)
{
interrupt_disable();
init_task_context(id);
tasks_ready |= 1 << id;
/* TODO: Clear all pending events? */
interrupt_enable();
}
/* We can't pass a parameter to a deferred call. Use this instead. */
/* Mask of task IDs waiting to be reset. */
static uint32_t deferred_reset_task_ids;
/* Tasks may call this function if they want to reset themselves. */
static void deferred_task_reset(void)
{
while (deferred_reset_task_ids) {
task_id_t reset_id = __fls(deferred_reset_task_ids);
atomic_clear(&deferred_reset_task_ids, 1 << reset_id);
do_task_reset(reset_id);
}
}
DECLARE_DEFERRED(deferred_task_reset);
/*
* Helper for updating task_reset state atomically. Checks the current state,
* and if it matches if_value, updates the state to new_value, and returns
* TRUE.
*/
static int update_reset_state(uint32_t *state,
uint32_t if_value,
uint32_t to_value)
{
int update;
interrupt_disable();
update = *state == if_value;
if (update)
*state = to_value;
interrupt_enable();
return update;
}
/*
* Helper that acquires the reset lock iff it is not currently held.
* Returns TRUE if the lock was acquired.
*/
static inline int try_acquire_reset_lock(uint32_t *state)
{
return update_reset_state(state,
/* if the lock is not held */
TASK_RESET_STATE_UNLOCKED,
/* acquire it */
TASK_RESET_STATE_LOCKED);
}
/*
* Helper that releases the reset lock iff it is currently held, and there
* are no pending resets. Returns TRUE if the lock was released.
*/
static inline int try_release_reset_lock(uint32_t *state)
{
return update_reset_state(state,
/* if the lock is held, with no waiters */
TASK_RESET_STATE_LOCKED,
/* release it */
TASK_RESET_STATE_UNLOCKED);
}
/*
* Helper to cause the current task to sleep indefinitely; useful if the
* calling task just needs to block until it is reset.
*/
static inline void sleep_forever(void)
{
while (1)
usleep(-1);
}
void task_enable_resets(void)
{
task_id_t id = task_get_current();
uint32_t *state = &task_reset_state[id];
if (*state == TASK_RESET_UNSUPPORTED) {
cprints(CC_TASK,
"%s called from non-resettable task, id: %d",
__func__, id);
return;
}
/*
* A correctly written resettable task will only call this function
* if resets are currently disabled; this implies that this task
* holds the reset lock.
*/
if (*state == TASK_RESET_STATE_UNLOCKED) {
cprints(CC_TASK,
"%s called, but resets already enabled, id: %d",
__func__, id);
return;
}
/*
* Attempt to release the lock. If we cannot, it means there are tasks
* waiting for a reset.
*/
if (try_release_reset_lock(state))
return;
/* People are waiting for us to reset; schedule a reset. */
atomic_or(&deferred_reset_task_ids, 1 << id);
/*
* This will always trigger a deferred call after our new ID was
* written. If the hook call is currently executing, it will run
* again.
*/
hook_call_deferred(&deferred_task_reset_data, 0);
/* Wait to be reset. */
sleep_forever();
}
void task_disable_resets(void)
{
task_id_t id = task_get_current();
uint32_t *state = &task_reset_state[id];
if (*state == TASK_RESET_UNSUPPORTED) {
cprints(CC_TASK,
"%s called from non-resettable task, id %d",
__func__, id);
return;
}
/*
* A correctly written resettable task will only call this function
* if resets are currently enabled; this implies that this task does
* not hold the reset lock.
*/
if (try_acquire_reset_lock(state))
return;
/*
* If we can't acquire the lock, we are about to be reset by another
* task.
*/
sleep_forever();
}
int task_reset_cleanup(void)
{
task_id_t id = task_get_current();
uint32_t *state = &task_reset_state[id];
/*
* If the task has never started before, state will be
* TASK_RESET_ENABLED.
*
* If the task was reset, the TASK_RESET_LOCK bit will be set, and
* there may additionally be bits representing tasks we must notify
* that we have reset.
*/
/*
* Only this task can unset the lock bit so we can read this safely,
* even though other tasks may be modifying the state to add themselves
* as waiters.
*/
int cleanup_req = *state & TASK_RESET_LOCK;
/*
* Attempt to release the lock. We can only do this when there are no
* tasks waiting to be notified that we have been reset, so we loop
* until no tasks are waiting.
*
* Other tasks may still be trying to reset us at this point; if they
* do, they will add themselves to the list of tasks we must notify. We
* will simply notify them (multiple times if necessary) until we are
* free to unlock.
*/
if (cleanup_req) {
while (!try_release_reset_lock(state)) {
/* Find the first waiter to notify. */
task_id_t notify_id = __fls(
*state & TASK_RESET_WAITERS_MASK);
/*
* Remove the task from waiters first, so that
* when it wakes after being notified, it is in
* a consistent state (it should not be waiting
* to be notified and running).
* After being notified, the task may try to
* reset us again; if it does, it will just add
* itself back to the list of tasks to notify,
* and we will notify it again.
*/
atomic_clear(state, 1 << notify_id);
/*
* Skip any invalid ids set by tasks that
* requested a non-blocking reset.
*/
if (notify_id < TASK_ID_COUNT)
task_set_event(notify_id,
TASK_EVENT_RESET_DONE,
0);
}
}
return cleanup_req;
}
int task_reset(task_id_t id, int wait)
{
task_id_t current = task_get_current();
uint32_t *state = &task_reset_state[id];
uint32_t waiter_id;
int resets_disabled;
if (id == current)
return EC_ERROR_INVAL;
/*
* This value is only set at compile time, and will never be modified.
*/
if (*state == TASK_RESET_UNSUPPORTED)
return EC_ERROR_INVAL;
/*
* If we are not blocking for reset, we use an invalid task id to notify
* the task that _someone_ wanted it to reset, but didn't want to be
* notified when the reset is complete.
*/
waiter_id = 1 << (wait ? current : TASK_ID_COUNT);
/*
* Try and take the lock. If we can't have it, just notify the task we
* tried; it will reset itself when it next tries to release the lock.
*/
interrupt_disable();
resets_disabled = *state & TASK_RESET_LOCK;
if (resets_disabled)
*state |= waiter_id;
else
*state |= TASK_RESET_LOCK;
interrupt_enable();
if (!resets_disabled) {
/* We got the lock, do the reset immediately. */
do_task_reset(id);
} else if (wait) {
/*
* We couldn't get the lock, and have been asked to block for
* reset. We have asked the task to reset itself; it will notify
* us when it has.
*/
task_wait_event_mask(TASK_EVENT_RESET_DONE, -1);
}
return EC_SUCCESS;
}
#endif /* CONFIG_TASK_RESET_LIST */
/*
* Initialize IRQs in the NVIC and set their priorities as defined by the
* DECLARE_IRQ statements.
*/
static void __nvic_init_irqs(void)
{
/* Get the IRQ priorities section from the linker */
int exc_calls = __irqprio_end - __irqprio;
int i;
/* Mask and clear all pending interrupts */
for (i = 0; i < 5; i++) {
CPU_NVIC_DIS(i) = 0xffffffff;
CPU_NVIC_UNPEND(i) = 0xffffffff;
}
/*
* Re-enable global interrupts in case they're disabled. On a reboot,
* they're already enabled; if we've jumped here from another image,
* they're not.
*/
interrupt_enable();
/* Set priorities */
for (i = 0; i < exc_calls; i++) {
uint8_t irq = __irqprio[i].irq;
uint8_t prio = __irqprio[i].priority;
uint32_t prio_shift = irq % 4 * 8 + 5;
if (prio > 0x7)
prio = 0x7;
CPU_NVIC_PRI(irq / 4) =
(CPU_NVIC_PRI(irq / 4) &
~(0x7 << prio_shift)) |
(prio << prio_shift);
}
}
void mutex_lock(struct mutex *mtx)
{
uint32_t value;
uint32_t id = 1 << task_get_current();
ASSERT(id != TASK_ID_INVALID);
atomic_or(&mtx->waiters, id);
do {
/* Try to get the lock (set 1 into the lock field) */
__asm__ __volatile__(" ldrex %0, [%1]\n"
" teq %0, #0\n"
" it eq\n"
" strexeq %0, %2, [%1]\n"
: "=&r" (value)
: "r" (&mtx->lock), "r" (2) : "cc");
/*
* "value" is equals to 1 if the store conditional failed,
* 2 if somebody else owns the mutex, 0 else.
*/
if (value == 2)
/* Contention on the mutex */
task_wait_event_mask(TASK_EVENT_MUTEX, 0);
} while (value);
atomic_clear(&mtx->waiters, id);
}
void mutex_unlock(struct mutex *mtx)
{
uint32_t waiters;
task_ *tsk = current_task;
/*
* Add a critical section to keep the unlock and the snapshotting of
* waiters atomic in case a task switching occurs between them.
*/
interrupt_disable();
waiters = mtx->waiters;
mtx->lock = 0;
interrupt_enable();
while (waiters) {
task_id_t id = __fls(waiters);
waiters &= ~(1 << id);
/* Somebody is waiting on the mutex */
task_set_event(id, TASK_EVENT_MUTEX, 0);
}
/* Ensure no event is remaining from mutex wake-up */
atomic_clear(&tsk->events, TASK_EVENT_MUTEX);
}
void task_print_list(void)
{
int i;
ccputs("Task Ready Name Events Time (s) StkUsed\n");
for (i = 0; i < TASK_ID_COUNT; i++) {
char is_ready = (tasks_ready & (1<<i)) ? 'R' : ' ';
uint32_t *sp;
int stackused = tasks_init[i].stack_size;
for (sp = tasks[i].stack;
sp < (uint32_t *)tasks[i].sp && *sp == STACK_UNUSED_VALUE;
sp++)
stackused -= sizeof(uint32_t);
ccprintf("%4d %c %-16s %08x %11.6ld %3d/%3d\n", i, is_ready,
task_names[i], tasks[i].events, tasks[i].runtime,
stackused, tasks_init[i].stack_size);
cflush();
}
}
int command_task_info(int argc, char **argv)
{
#ifdef CONFIG_TASK_PROFILING
int total = 0;
int i;
#endif
task_print_list();
#ifdef CONFIG_TASK_PROFILING
ccputs("IRQ counts by type:\n");
cflush();
for (i = 0; i < ARRAY_SIZE(irq_dist); i++) {
if (irq_dist[i]) {
ccprintf("%4d %8d\n", i, irq_dist[i]);
total += irq_dist[i];
}
}
ccprintf("Service calls: %11d\n", svc_calls);
ccprintf("Total exceptions: %11d\n", total + svc_calls);
ccprintf("Task switches: %11d\n", task_switches);
ccprintf("Task switching started: %11.6ld s\n", task_start_time);
ccprintf("Time in tasks: %11.6ld s\n",
get_time().val - task_start_time);
ccprintf("Time in exceptions: %11.6ld s\n", exc_total_time);
#endif
return EC_SUCCESS;
}
DECLARE_SAFE_CONSOLE_COMMAND(taskinfo, command_task_info,
NULL,
"Print task info");
#ifdef CONFIG_CMD_TASKREADY
static int command_task_ready(int argc, char **argv)
{
if (argc < 2) {
ccprintf("tasks_ready: 0x%08x\n", tasks_ready);
} else {
tasks_ready = strtoi(argv[1], NULL, 16);
ccprintf("Setting tasks_ready to 0x%08x\n", tasks_ready);
__schedule(0, 0);
}
return EC_SUCCESS;
}
DECLARE_CONSOLE_COMMAND(taskready, command_task_ready,
"[setmask]",
"Print/set ready tasks");
#endif
void task_pre_init(void)
{
uint32_t *stack_next = (uint32_t *)task_stacks;
int i;
/* Fill the task memory with initial values */
for (i = 0; i < TASK_ID_COUNT; i++) {
tasks[i].stack = stack_next;
stack_next += init_task_context(i);
}
/*
* Fill in guard value in scratchpad to prevent stack overflow
* detection failure on the first context switch. This works because
* the first word in the scratchpad is where the switcher will store
* sp, so it's ok to blow away.
*/
((task_ *)scratchpad)->stack = (uint32_t *)scratchpad;
*(uint32_t *)scratchpad = STACK_UNUSED_VALUE;
/* Initialize IRQs */
__nvic_init_irqs();
}
void task_clear_fp_used(void)
{
int ctrl;
/* Clear the CONTROL.FPCA bit, which represents FP context active. */
asm volatile("mrs %0, control" : "=r"(ctrl));
ctrl &= ~0x4;
asm volatile("msr control, %0" : : "r"(ctrl));
/* Flush pipeline before returning. */
asm volatile("isb");
}
int task_start(void)
{
#ifdef CONFIG_TASK_PROFILING
timestamp_t t = get_time();
task_start_time = t.val;
exc_end_time = t.le.lo;
#endif
start_called = 1;
return __task_start(&need_resched_or_profiling);
}
#ifdef CONFIG_CMD_TASK_RESET
static int command_task_reset(int argc, char **argv)
{
task_id_t id;
char *e;
if (argc == 2) {
id = strtoi(argv[1], &e, 10);
if (*e)
return EC_ERROR_PARAM1;
ccprintf("Resetting task %d\n", id);
return task_reset(id, 1);
}
return EC_ERROR_PARAM_COUNT;
}
DECLARE_CONSOLE_COMMAND(taskreset, command_task_reset,
"task_id",
"Reset a task");
#endif /* CONFIG_CMD_TASK_RESET */
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