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/*

 * Copyright (C) 2005 Martin Decky

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * - Redistributions of source code must retain the above copyright

 *   notice, this list of conditions and the following disclaimer.

 * - Redistributions in binary form must reproduce the above copyright

 *   notice, this list of conditions and the following disclaimer in the

 *   documentation and/or other materials provided with the distribution.

 * - The name of the author may not be used to endorse or promote products

 *   derived from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <syscall/syscall.h>

#include <proc/thread.h>

#include <mm/as.h>

#include <print.h>

#include <putchar.h>

#include <ipc/ipc.h>

#include <errno.h>

#include <proc/task.h>

#include <arch.h>

#include <debug.h>

static __native sys_ctl(void) {

	printf("Thread finished\n");

	thread_exit();

	/* Unreachable */

	return 0;

}

static __native sys_io(int fd, const void * buf, size_t count) {

	// TODO: buf sanity checks and a lot of other stuff ...

	size_t i;

	for (i = 0; i < count; i++)

		putchar(((char *) buf)[i]);

	return count;

}

static phone_t * get_phone(__native phoneid)

{

	phone_t *phone;

	if (phoneid >= IPC_MAX_PHONES)

		return NULL;

	phone = &TASK->phones[phoneid];

	if (!phone->callee)

		return NULL;

	return phone;

}

/** Send a call over IPC, wait for reply, return to user

 *

 * @return Call identification, returns -1 on fatal error, 

           -2 on 'Too many async request, handle answers first

 */

static __native sys_ipc_call_sync_fast(__native phoneid, __native method, 

				       __native arg1, __native *data)

{

	call_t call;

	phone_t *phone;

	/* Special answerbox for synchronous messages */

	phone = get_phone(phoneid);

	if (!phone)

		return IPC_CALLRET_FATAL;

	ipc_call_init(&call);

	IPC_SET_METHOD(call.data, method);

	IPC_SET_ARG1(call.data, arg1);

	ipc_call_sync(phone, &call);

	copy_to_uspace(data, &call.data, sizeof(call.data));

	return 0;

}

/** Synchronous IPC call allowing to send whole message */

static __native sys_ipc_call_sync(__native phoneid, __native *data)

{

	call_t call;

	phone_t *phone;

	/* Special answerbox for synchronous messages */

	phone = get_phone(phoneid);

	if (!phone)

		return IPC_CALLRET_FATAL;

	ipc_call_init(&call);

	copy_from_uspace(&call.data, data, sizeof(call.data));

	ipc_call_sync(phone, &call);

	copy_to_uspace(data, &call.data, sizeof(call.data));

	return 0;

}

/** Check that the task did not exceed allowed limit

 *

 * @return 0 - Limit OK,   -1 - limit exceeded

 */

static int check_call_limit(void)

{

	if (atomic_inc_post(&TASK->active_calls) > IPC_MAX_ASYNC_CALLS) {

		atomic_dec(&TASK->active_calls);

		return -1;

	}

	return 0;

}

/** Send an asynchronous call over ipc

 *

 * @return Call identification, returns -1 on fatal error, 

           -2 on 'Too many async request, handle answers first

 */

static __native sys_ipc_call_async_fast(__native phoneid, __native method, 

					__native arg1, __native arg2)

{

	call_t *call;

	phone_t *phone;

	phone = get_phone(phoneid);

	if (!phone)

		return IPC_CALLRET_FATAL;

	if (check_call_limit())

		return IPC_CALLRET_TEMPORARY;

	call = ipc_call_alloc();

	IPC_SET_METHOD(call->data, method);

	IPC_SET_ARG1(call->data, arg1);

	IPC_SET_ARG2(call->data, arg2);

	ipc_call(phone, call);

	return (__native) call;

}

/** Synchronous IPC call allowing to send whole message

 *

 * @return The same as sys_ipc_call_async

 */

static __native sys_ipc_call_async(__native phoneid, __native *data)

{

	call_t *call;

	phone_t *phone;

	phone = get_phone(phoneid);

	if (!phone)

		return IPC_CALLRET_FATAL;

	if (check_call_limit())

		return IPC_CALLRET_TEMPORARY;

	call = ipc_call_alloc();

	copy_from_uspace(&call->data, data, sizeof(call->data));

	ipc_call(phone, call);

	return (__native) call;

}

/** Send IPC answer */

static __native sys_ipc_answer(__native callid, __native retval, __native arg1,

			       __native arg2)

{

	call_t *call;

	/* Check that the user is not sending us answer callid */

	ASSERT(! (callid & 1));

	/* TODO: Check that the callid is in the dispatch table */

	call = (call_t *) callid;

	IPC_SET_RETVAL(call->data, retval);

	IPC_SET_ARG1(call->data, arg1);

	IPC_SET_ARG2(call->data, arg2);

	ipc_answer(&TASK->answerbox, call);

	return 0;

}

/** Wait for incoming ipc call or answer

 *

 * @param result 

 * @param flags

 * @return Callid, if callid & 1, then the call is answer

 */

static __native sys_ipc_wait_for_call(__native *calldata, __native flags)

{

	call_t *call;

	call = ipc_wait_for_call(&TASK->answerbox, flags);

	copy_to_uspace(calldata, &call->data, sizeof(call->data));

	if (call->flags & IPC_CALL_ANSWERED) {

		ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));

		ipc_call_free(call);

		atomic_dec(&TASK->active_calls);

		return ((__native)call) | IPC_CALLID_ANSWERED;

	}

	return (__native)call;

}

static __native sys_mremap(void *address, size_t size, unsigned long flags)

{

	return as_remap(AS, (__address) address, size, 0);

}

syshandler_t syscall_table[SYSCALL_END] = {

	sys_ctl,

	sys_io,

	sys_mremap,

	sys_ipc_call_sync_fast,

	sys_ipc_call_sync,

	sys_ipc_call_async_fast,

	sys_ipc_call_async,

	sys_ipc_answer,

	sys_ipc_wait_for_call

};