1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/* 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"
/* Disables CPU interrupt bit. This might break the system so think really hard
* before using these. There are usually better ways of accomplishing this. */
void interrupt_disable(void);
/* Enables CPU interrupt */
void interrupt_enable(void);
/**
* 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);
/**
* Waits 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);
/**
* Changes 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);
/* Initializes tasks and interrupt controller. */
int task_init(void);
/* Starts task scheduling. */
int task_start(void);
/* Enables an interrupt. */
void task_enable_irq(int irq);
/* Disables an interrupt. */
void task_disable_irq(int irq);
/* Software-triggers an interrupt. */
void task_trigger_irq(int irq);
struct mutex {
uint32_t lock;
uint32_t waiters;
};
/**
* try to lock the mutex mtx
* and de-schedule the task if it is already locked by another task.
*
* Should not be used in interrupt context !
*/
void mutex_lock(struct mutex *mtx);
/* Release a mutex previously locked by the same task. */
void mutex_unlock(struct mutex *mtx);
struct irq_priority {
uint8_t irq;
uint8_t priority;
};
/* Helper macros to build the IRQ handler name */
#define IRQ_BUILD_NAME(prefix, irqnum, postfix) prefix ## irqnum ## postfix
#define IRQ_HANDLER(irqname) IRQ_BUILD_NAME(irq_,irqname,_handler)
/**
* Connects the interrupt handler "routine" to the irq number "irq" and
* ensures it is enabled in the interrupt controller with the right priority.
*/
#define DECLARE_IRQ(irq, routine, priority) \
void IRQ_HANDLER(irq)(void) \
{ \
void *ret = __builtin_return_address(0); \
routine(); \
task_resched_if_needed(ret); \
} \
const struct irq_priority IRQ_BUILD_NAME(prio_, irq, ) \
__attribute__((section(".rodata.irqprio"))) \
= {irq, priority}
#endif /* __EC_TASK_H */
|
