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/*

 * Copyright (c) 2006 Ondrej Palkovsky

 * 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.

 */

/** @addtogroup libc

 * @{

 * @}

 */

/** @addtogroup libcipc IPC

 * @brief HelenOS uspace IPC

 * @{

 * @ingroup libc

 */

/** @file

 */ 

#include <ipc/ipc.h>

#include <libc.h>

#include <malloc.h>

#include <errno.h>

#include <libadt/list.h>

#include <stdio.h>

#include <unistd.h>

#include <futex.h>

#include <kernel/synch/synch.h>

#include <async.h>

#include <fibril.h>

/**

 * Structures of this type are used for keeping track of sent asynchronous calls

 * and queing unsent calls.

 */

typedef struct {

	link_t list;

	ipc_async_callback_t callback;

	void *private;

	union {

		ipc_callid_t callid;

		struct {

			ipc_call_t data;

			int phoneid;

		} msg;

	} u;

	fid_t fid;	/**< Fibril waiting for sending this call. */

} async_call_t;

LIST_INITIALIZE(dispatched_calls);

/** List of asynchronous calls that were not accepted by kernel.

 *

 * It is protected by async_futex, because if the call cannot be sent into the

 * kernel, the async framework is used automatically.

 */

LIST_INITIALIZE(queued_calls);

static atomic_t ipc_futex = FUTEX_INITIALIZER;

/** Make a fast synchronous call.

 *

 * Only one payload argument can be passed using this function. However, this

 * function is faster than the generic ipc_call_sync_3().

 *

 * @param phoneid	Phone handle for the call.

 * @param method	Requested method.

 * @param arg1		Service-defined payload argument.

 * @param result	If non-NULL, the return ARG1 will be stored there.

 *

 * @return		Negative values represent errors returned by IPC.

 *			Otherwise the RETVAL of the answer is returned.

 */

int ipc_call_sync(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t *result)

{

	ipc_call_t resdata;

	int callres;

	callres = __SYSCALL4(SYS_IPC_CALL_SYNC_FAST, phoneid, method, arg1,

	    (sysarg_t) &resdata);

	if (callres)

		return callres;

	if (result)

		*result = IPC_GET_ARG1(resdata);

	return IPC_GET_RETVAL(resdata);

}

/** Make a synchronous call transmitting 3 arguments of payload.

 *

 * @param phoneid	Phone handle for the call.

 * @param method	Requested method.

 * @param arg1		Service-defined payload argument.

 * @param arg2		Service-defined payload argument.

 * @param arg3		Service-defined payload argument.

 * @param result1	If non-NULL, storage for the first return argument.

 * @param result2	If non-NULL, storage for the second return argument.

 * @param result3	If non-NULL, storage for the third return argument.

 *

 * @return		Negative value means IPC error.

 *			Otherwise the RETVAL of the answer.

 */

int ipc_call_sync_3(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,

    ipcarg_t arg3, ipcarg_t *result1, ipcarg_t *result2, ipcarg_t *result3)

{

	ipc_call_t data;

	int callres;

	IPC_SET_METHOD(data, method);

	IPC_SET_ARG1(data, arg1);

	IPC_SET_ARG2(data, arg2);

	IPC_SET_ARG3(data, arg3);

	callres = __SYSCALL3(SYS_IPC_CALL_SYNC, phoneid, (sysarg_t) &data,

	    (sysarg_t) &data);

	if (callres)

		return callres;

	if (result1)

		*result1 = IPC_GET_ARG1(data);

	if (result2)

		*result2 = IPC_GET_ARG2(data);

	if (result3)

		*result3 = IPC_GET_ARG3(data);

	return IPC_GET_RETVAL(data);

}

/** Syscall to send asynchronous message.

 *

 * @param phoneid	Phone handle for the call.

 * @param data		Call data with the request.

 *

 * @return		Hash of the call or an error code.

 */

static ipc_callid_t _ipc_call_async(int phoneid, ipc_call_t *data)

{

	return __SYSCALL2(SYS_IPC_CALL_ASYNC, phoneid, (sysarg_t) data);

}

/** Prolog to ipc_call_async_*() functions.

 *

 * @param private	Argument for the answer/error callback.

 * @param callback	Answer/error callback.

 *

 * @return		New, partially initialized async_call structure or NULL.

 */

static inline async_call_t *ipc_prepare_async(void *private,

    ipc_async_callback_t callback)

{

	async_call_t *call;

	call = malloc(sizeof(*call));

	if (!call) {

		if (callback)

			callback(private, ENOMEM, NULL);

		return NULL;

	}

	call->callback = callback;

	call->private = private;

	return call;

}

/** Epilogue of ipc_call_async_*() functions.

 *

 * @param callid	Value returned by the SYS_IPC_CALL_ASYNC_* syscall.

 * @param phoneid	Phone handle through which the call was made.

 * @param call		async_call structure returned by ipc_prepare_async().

 * @param can_preempt	If non-zero, the current pseudo thread can be preempted

 *			in this call.

 */

static inline void ipc_finish_async(ipc_callid_t callid, int phoneid,

    async_call_t *call, int can_preempt)

{

	if (!call) { /* Nothing to do regardless if failed or not */

		futex_up(&ipc_futex);

		return;

	}

	if (callid == IPC_CALLRET_FATAL) {

		futex_up(&ipc_futex);

		/* Call asynchronous handler with error code */

		if (call->callback)

			call->callback(call->private, ENOENT, NULL);

		free(call);

		return;

	}

	if (callid == IPC_CALLRET_TEMPORARY) {

		futex_up(&ipc_futex);

		call->u.msg.phoneid = phoneid;

		futex_down(&async_futex);

		list_append(&call->list, &queued_calls);

		if (can_preempt) {

			call->fid = fibril_get_id();

			fibril_schedule_next_adv(FIBRIL_TO_MANAGER);

			/* Async futex unlocked by previous call */

		} else {

			call->fid = 0;

			futex_up(&async_futex);

		}

		return;

	}

	call->u.callid = callid;

	/* Add call to the list of dispatched calls */

	list_append(&call->list, &dispatched_calls);

	futex_up(&ipc_futex);

}

/** Make a fast asynchronous call.

 *

 * This function can only handle two arguments of payload. It is, however,

 * faster than the more generic ipc_call_async_3().

 *

 * Note that this function is a void function.

 * During normal opertation, answering this call will trigger the callback.

 * In case of fatal error, call the callback handler with the proper error code.

 * If the call cannot be temporarily made, queue it.

 *

 * @param phoneid	Phone handle for the call.

 * @param method	Requested method.

 * @param arg1		Service-defined payload argument.

 * @param arg2		Service-defined payload argument.

 * @param private	Argument to be passed to the answer/error callback.

 * @param callback	Answer or error callback.

 * @param can_preempt	If non-zero, the current pseudo thread will be preempted

 *			in case the kernel temporarily refuses to accept more

 *			asynchronous calls.

 */

void ipc_call_async_2(int phoneid, ipcarg_t method, ipcarg_t arg1,

    ipcarg_t arg2, void *private, ipc_async_callback_t callback,

    int can_preempt)

{

	async_call_t *call = NULL;

	ipc_callid_t callid;

	if (callback) {

		call = ipc_prepare_async(private, callback);

		if (!call)

			return;

	}

	/*

	 * We need to make sure that we get callid before another thread

	 * accesses the queue again.

	 */

	futex_down(&ipc_futex);

	callid = __SYSCALL4(SYS_IPC_CALL_ASYNC_FAST, phoneid, method, arg1,

	    arg2);

	if (callid == IPC_CALLRET_TEMPORARY) {

		if (!call) {

			call = ipc_prepare_async(private, callback);

			if (!call)

				return;

		}

		IPC_SET_METHOD(call->u.msg.data, method);

		IPC_SET_ARG1(call->u.msg.data, arg1);

		IPC_SET_ARG2(call->u.msg.data, arg2);

	}

	ipc_finish_async(callid, phoneid, call, can_preempt);

}

/** Make an asynchronous call transmitting the entire payload.

 *

 * Note that this function is a void function.

 * During normal opertation, answering this call will trigger the callback.

 * In case of fatal error, call the callback handler with the proper error code.

 * If the call cannot be temporarily made, queue it.

 *

 * @param phoneid	Phone handle for the call.

 * @param method	Requested method.

 * @param arg1		Service-defined payload argument.

 * @param arg2		Service-defined payload argument.

 * @param arg3		Service-defined payload argument.

 * @param private	Argument to be passed to the answer/error callback.

 * @param callback	Answer or error callback.

 * @param can_preempt	If non-zero, the current pseudo thread will be preempted

 *			in case the kernel temporarily refuses to accept more

 *			asynchronous calls.

 *

 */

void ipc_call_async_3(int phoneid, ipcarg_t method, ipcarg_t arg1,

    ipcarg_t arg2, ipcarg_t arg3, void *private, ipc_async_callback_t callback,

    int can_preempt)

{

	async_call_t *call;

	ipc_callid_t callid;

	call = ipc_prepare_async(private, callback);

	if (!call)

		return;

	IPC_SET_METHOD(call->u.msg.data, method);

	IPC_SET_ARG1(call->u.msg.data, arg1);

	IPC_SET_ARG2(call->u.msg.data, arg2);

	IPC_SET_ARG3(call->u.msg.data, arg3);

	/*

	 * We need to make sure that we get callid before another thread accesses

	 * the queue again.

	 */

	futex_down(&ipc_futex);

	callid = _ipc_call_async(phoneid, &call->u.msg.data);

	ipc_finish_async(callid, phoneid, call, can_preempt);

}

/** Answer a received call - fast version.

 *

 * The fast answer makes use of passing retval and first two arguments in

 * registers. If you need to return more, use the ipc_answer() instead.

 *

 * @param callid	Hash of the call being answered.

 * @param retval	Return value.

 * @param arg1		First return argument.

 * @param arg2		Second return argument.

 *

 * @return		Zero on success or a value from @ref errno.h on failure.

 */

ipcarg_t ipc_answer_fast(ipc_callid_t callid, ipcarg_t retval, ipcarg_t arg1,

    ipcarg_t arg2)

{

	return __SYSCALL4(SYS_IPC_ANSWER_FAST, callid, retval, arg1, arg2);

}

/** Answer a received call - full version.

 *

 * @param callid	Hash of the call being answered.

 * @param call 		Call structure with the answer.

 *			Must be already initialized by the responder.

 *

 * @return		Zero on success or a value from @ref errno.h on failure.

 */

ipcarg_t ipc_answer(ipc_callid_t callid, ipc_call_t *call)

{

	return __SYSCALL2(SYS_IPC_ANSWER, callid, (sysarg_t) call);

}

/** Try to dispatch queued calls from the async queue. */

static void try_dispatch_queued_calls(void)

{

	async_call_t *call;

	ipc_callid_t callid;

	/** @todo

	 * Integrate intelligently ipc_futex, so that it is locked during

	 * ipc_call_async_*(), until it is added to dispatched_calls.

	 */

	futex_down(&async_futex);

	while (!list_empty(&queued_calls)) {

		call = list_get_instance(queued_calls.next, async_call_t, list);

		callid = _ipc_call_async(call->u.msg.phoneid, &call->u.msg.data);

		if (callid == IPC_CALLRET_TEMPORARY) {

			break;

		}

		list_remove(&call->list);

		futex_up(&async_futex);

		if (call->fid)

			fibril_add_ready(call->fid);

		if (callid == IPC_CALLRET_FATAL) {

			if (call->callback)

				call->callback(call->private, ENOENT, NULL);

			free(call);

		} else {

			call->u.callid = callid;

			futex_down(&ipc_futex);

			list_append(&call->list, &dispatched_calls);

			futex_up(&ipc_futex);

		}

		futex_down(&async_futex);

	}

	futex_up(&async_futex);

}

/** Handle a received answer.

 *

 * Find the hash of the answer and call the answer callback.

 *

 * @todo Make it use hash table.

 *

 * @param callid	Hash of the received answer.

 *			The answer has the same hash as the request OR'ed with

 *			the IPC_CALLID_ANSWERED bit.

 * @param data		Call data of the answer.

 */

static void handle_answer(ipc_callid_t callid, ipc_call_t *data)

{

	link_t *item;

	async_call_t *call;

	callid &= ~IPC_CALLID_ANSWERED;

	futex_down(&ipc_futex);

	for (item = dispatched_calls.next; item != &dispatched_calls;

	    item = item->next) {

		call = list_get_instance(item, async_call_t, list);

		if (call->u.callid == callid) {

			list_remove(&call->list);

			futex_up(&ipc_futex);

			if (call->callback)

				call->callback(call->private, 

				    IPC_GET_RETVAL(*data), data);

			free(call);

			return;

		}

	}

	futex_up(&ipc_futex);

}

/** Wait for a first call to come.

 *

 * @param call		Storage where the incoming call data will be stored.

 * @param usec		Timeout in microseconds

 * @param flags		Flags passed to SYS_IPC_WAIT (blocking, nonblocking).

 *

 * @return		Hash of the call. Note that certain bits have special

 *			meaning. IPC_CALLID_ANSWERED will be set in an answer

 *			and IPC_CALLID_NOTIFICATION is used for notifications.

 *			

 */

ipc_callid_t ipc_wait_cycle(ipc_call_t *call, uint32_t usec, int flags)

{

	ipc_callid_t callid;

	callid = __SYSCALL3(SYS_IPC_WAIT, (sysarg_t) call, usec, flags);

	/* Handle received answers */

	if (callid & IPC_CALLID_ANSWERED) {

		handle_answer(callid, call);

		try_dispatch_queued_calls();

	}

	return callid;

}

/** Wait some time for an IPC call.

 *

 * The call will return after an answer is received.

 *

 * @param call		Storage where the incoming call data will be stored.

 * @param usec		Timeout in microseconds.

 *

 * @return		Hash of the answer.

 */

ipc_callid_t ipc_wait_for_call_timeout(ipc_call_t *call, uint32_t usec)

{

	ipc_callid_t callid;

	do {

		callid = ipc_wait_cycle(call, usec, SYNCH_FLAGS_NONE);

	} while (callid & IPC_CALLID_ANSWERED);

	return callid;

}

/** Check if there is an IPC call waiting to be picked up.

 *

 * @param call		Storage where the incoming call will be stored.

 * @return		Hash of the answer.

 */

ipc_callid_t ipc_trywait_for_call(ipc_call_t *call)

{

	ipc_callid_t callid;

	do {

		callid = ipc_wait_cycle(call, SYNCH_NO_TIMEOUT,

		    SYNCH_FLAGS_NON_BLOCKING);

	} while (callid & IPC_CALLID_ANSWERED);

	return callid;

}

/** Ask destination to do a callback connection.

 *

 * @param phoneid	Phone handle used for contacting the other side.

 * @param arg1		Service-defined argument.

 * @param arg2		Service-defined argument.

 * @param phonehash	Storage where the library will store an opaque

 *			identifier of the phone that will be used for incoming

 *			calls. This identifier can be used for connection

 *			tracking.

 *

 * @return		Zero on success or a negative error code.

 */

int ipc_connect_to_me(int phoneid, int arg1, int arg2, ipcarg_t *phonehash)

{

	return ipc_call_sync_3(phoneid, IPC_M_CONNECT_TO_ME, arg1, arg2, 0, 0, 0,

	    phonehash);

}

/** Ask through phone for a new connection to some service.

 *

 * @param phoneid	Phone handle used for contacting the other side.

 * @param arg1		User defined argument.

 * @param arg2		User defined argument.

 *

 * @return		New phone handle on success or a negative error code.

 */

int ipc_connect_me_to(int phoneid, int arg1, int arg2)

{

	ipcarg_t newphid;

	int res;

	res =  ipc_call_sync_3(phoneid, IPC_M_CONNECT_ME_TO, arg1, arg2, 0, 0, 0,

	    &newphid);

	if (res)

		return res;

	return newphid;

}

/** Hang up a phone.

 *

 * @param phoneid	Handle of the phone to be hung up.

 *

 * @return		Zero on success or a negative error code.

 */

int ipc_hangup(int phoneid)

{

	return __SYSCALL1(SYS_IPC_HANGUP, phoneid);

}

/** Register IRQ notification.

 *

 * @param inr		IRQ number.

 * @param devno		Device number of the device generating inr.

 * @param method	Use this method for notifying me.

 * @param ucode		Top-half pseudocode handler.

 *

 * @return		Value returned by the kernel.

 */

int ipc_register_irq(int inr, int devno, int method, irq_code_t *ucode)

{

	return __SYSCALL4(SYS_IPC_REGISTER_IRQ, inr, devno, method,

	    (sysarg_t) ucode);

}

/** Unregister IRQ notification.

 *

 * @param inr		IRQ number.

 * @param devno		Device number of the device generating inr.

 *

 * @return		Value returned by the kernel.

 */

int ipc_unregister_irq(int inr, int devno)

{

	return __SYSCALL2(SYS_IPC_UNREGISTER_IRQ, inr, devno);

}

/** Forward a received call to another destination.

 *

 * @param callid	Hash of the call to forward.

 * @param phoneid	Phone handle to use for forwarding.

 * @param method	New method for the forwarded call.

 * @param arg1		New value of the first argument for the forwarded call.

 *

 * @return		Zero on success or an error code.

 *

 * For non-system methods, the old method and arg1 are rewritten by the new

 * values. For system methods, the new method and arg1 are written to the old

 * arg1 and arg2, respectivelly.

 */

int ipc_forward_fast(ipc_callid_t callid, int phoneid, int method, ipcarg_t arg1)

{

	return __SYSCALL4(SYS_IPC_FORWARD_FAST, callid, phoneid, method, arg1);

}

/** @}

 */