Initial sources import 3/3

source files mainly done by Vincent.

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

Change-Id: Ic2d1becd400c9b4b4a14d4a243af1bdf77d9c1e2

1 files changed, 95 insertions, 0 deletions

diff --git a/include/task.h b/include/task.h
new file mode 100644
index 0000000000..35bbc46943
--- /dev/null
+++ b/include/task.h
@@ -0,0 +1,95 @@
+/* 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 */