Files
OpenCellular/include/task.h
Vincent Palatin e24fa592d2 Initial sources import 3/3
source files mainly done by Vincent.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

Change-Id: Ic2d1becd400c9b4b4a14d4a243af1bdf77d9c1e2
2011-12-07 19:10:02 +00:00

96 lines
2.7 KiB
C

/* Copyright (c) 2011 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 */
#ifndef __EC_TASK_H
#define __EC_TASK_H
#include "common.h"
#include "task_id.h"
/**
* Return true if we are in interrupt context
*/
inline int in_interrupt_context(void);
/**
* Send a message to a task and wake it up if it is higher priority than us
*
* tskid : identifier of the receiver task
* from : identifier of the sender of the message
* wait : after sending, de-schedule the calling task to wait for the answer
*
* returns the bitmap of events which have occured.
*
* Can be called both in interrupt context and task context.
*/
uint32_t task_send_msg(task_id_t tskid, task_id_t from, int wait);
/**
* Return the identifier of the task currently running
*
* when called in interrupt context, returns TASK_ID_INVALID
*/
task_id_t task_get_current(void);
/**
* Return a pointer to the bitmap of received events of the task.
*/
uint32_t *task_get_event_bitmap(task_id_t tsk);
/**
* Wait for the incoming next message.
*
* if an event is already pending, it returns it immediatly, else it
* de-schedules the calling task and wake up the next one in the priority order
*
* if timeout_us > 0, it also sets a timer to produce an event after the
* specified micro-second duration.
*
* returns the bitmap of received events (and clear it atomically).
*/
uint32_t task_wait_msg(int timeout_us);
/**
* Change the task scheduled after returning from the exception.
*
* If task_send_msg has been called and has set need_resched flag,
* we re-compute which task is running and eventually swap the context
* saved on the process stack to restore the new one at exception exit.
*
* it must be called from interrupt context !
* and it is designed to be the last call of the interrupt handler.
*/
void task_resched_if_needed(void *excep_return);
/* Initialize tasks and interrupt controller */
int task_init(void);
/* Start the task scheduling */
int task_start(void);
struct irq_priority {
uint8_t irq;
uint8_t priority;
};
/**
* Connect the interrupt handler "routine" to the irq number "irq" and
* ensure it is enabled in the interrupt controller with the right priority
*/
#define DECLARE_IRQ(irq, routine, priority) \
void irq_##irq##_handler(void) \
{ \
void *ret = __builtin_return_address(0); \
routine(); \
task_resched_if_needed(ret); \
} \
const struct irq_priority prio_##irq \
__attribute__((section(".rodata.irqprio"))) \
= {irq, priority}
#endif /* __EC_TASK_H */