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Diffstat (limited to 'core/cortex-m/task.c')
| -rw-r--r-- | core/cortex-m/task.c | 1088 |
1 files changed, 0 insertions, 1088 deletions
diff --git a/core/cortex-m/task.c b/core/cortex-m/task.c deleted file mode 100644 index bf0eb5b397..0000000000 --- a/core/cortex-m/task.c +++ /dev/null @@ -1,1088 +0,0 @@ -/* Copyright 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 */ - -/* Validity 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(BIT(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 = BIT(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 = BIT(TASK_ID_HOOKS) | BIT(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 is_interrupt_enabled(void) -{ - int primask; - - /* Interrupts are enabled when PRIMASK bit is 0 */ - asm("mrs %0, primask":"=r"(primask)); - - return !(primask & 0x1); -} - -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; -} - -#ifdef CONFIG_TASK_PROFILING -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 */ -} -#endif - -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)); - - /* - * Scheduling task when interrupts are disabled will result in Forced - * Hard Fault because: - * - Disabling interrupt using 'cpsid i' also disables SVCall handler - * (because it has configurable priority) - * - Escalation to Hard Fault (also known as 'priority escalation') - * occurs when handler for that fault is not enabled - */ - ASSERT(is_interrupt_enabled()); - 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_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_bits(&tsk->events, TASK_EVENT_TIMER); - } - return evt; -} - -uint32_t task_set_event(task_id_t tskid, uint32_t event) -{ - 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() || !is_interrupt_enabled()) { - /* 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 { - __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 = BIT(TASK_ID_COUNT) - 1; - /* Reschedule the highest priority task. */ - if (is_interrupt_enabled()) - __schedule(0, 0); -} - -void task_enable_task(task_id_t tskid) -{ - atomic_or(&tasks_enabled, BIT(tskid)); -} - -void task_disable_task(task_id_t tskid) -{ - atomic_clear_bits(&tasks_enabled, BIT(tskid)); - - if (!in_interrupt_context() && is_interrupt_enabled() && - tskid == task_get_current()) - __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_bits(&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_bits(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); - } - } - - 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++) { - cpu_set_interrupt_priority(__irqprio[i].irq, - __irqprio[i].priority); - } -} - -void mutex_lock(struct mutex *mtx) -{ - uint32_t value; - uint32_t id; - - /* - * mutex_lock() must not be used in interrupt context (because we wait - * if there is contention). - */ - ASSERT(!in_interrupt_context()); - - /* - * Task ID is not valid before task_start() (since current_task is - * scratchpad), and no need for mutex locking before task switching has - * begun. - */ - if (!task_start_called()) - return; - - id = 1 << task_get_current(); - - 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_bits(&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 &= ~BIT(id); - - /* Somebody is waiting on the mutex */ - task_set_event(id, TASK_EVENT_MUTEX); - } - - /* Ensure no event is remaining from mutex wake-up */ - atomic_clear_bits(&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 %11.6lld %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: %11.6lld s\n", task_start_time); - ccprintf("Time in tasks: %11.6lld s\n", - get_time().val - task_start_time); - ccprintf("Time in exceptions: %11.6lld 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 */ |