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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 genericipc

 * @{

 */

/** @file

 */

#ifndef KERN_IPC_H_

#define KERN_IPC_H_

/* Length of data being transfered with IPC call */

/* - the uspace may not be able to utilize full length */

#define IPC_CALL_LEN		6	

/** Maximum active async calls per thread */

#ifdef CONFIG_DEBUG

#define IPC_MAX_ASYNC_CALLS	4

#else

#define IPC_MAX_ASYNC_CALLS	4000

#endif

/* Flags for calls */

/** This is answer to a call */

#define IPC_CALL_ANSWERED	(1 << 0)

/** This call will not be freed on error */

#define IPC_CALL_STATIC_ALLOC	(1 << 1)

/** Answer will not be passed to userspace, will be discarded */

#define IPC_CALL_DISCARD_ANSWER	(1 << 2)

/** Call was forwarded */

#define IPC_CALL_FORWARDED	(1 << 3)

/** Identify connect_me_to answer */

#define IPC_CALL_CONN_ME_TO	(1 << 4)

/** Interrupt notification */

#define IPC_CALL_NOTIF		(1 << 5)

/*

 * Bits used in call hashes.

 * The addresses are aligned at least to 4 that is why we can use the 2 least

 * significant bits of the call address.

 */

/** Type of this call is 'answer' */

#define IPC_CALLID_ANSWERED	1

/** Type of this call is 'notification' */

#define IPC_CALLID_NOTIFICATION	2

/* Return values from sys_ipc_call_async(). */

#define IPC_CALLRET_FATAL	-1

#define IPC_CALLRET_TEMPORARY	-2

/* Macros for manipulating calling data */

#define IPC_SET_RETVAL(data, retval)	((data).args[0] = (retval))

#define IPC_SET_METHOD(data, val)	((data).args[0] = (val))

#define IPC_SET_ARG1(data, val)		((data).args[1] = (val))

#define IPC_SET_ARG2(data, val)		((data).args[2] = (val))

#define IPC_SET_ARG3(data, val)		((data).args[3] = (val))

#define IPC_SET_ARG4(data, val)		((data).args[4] = (val))

#define IPC_SET_ARG5(data, val)		((data).args[5] = (val))

#define IPC_GET_METHOD(data)		((data).args[0])

#define IPC_GET_RETVAL(data)		((data).args[0])

#define IPC_GET_ARG1(data)		((data).args[1])

#define IPC_GET_ARG2(data)		((data).args[2])

#define IPC_GET_ARG3(data)		((data).args[3])

#define IPC_GET_ARG4(data)		((data).args[4])

#define IPC_GET_ARG5(data)		((data).args[5])

/* Well known phone descriptors */

#define PHONE_NS	0

/* Forwarding flags. */

#define IPC_FF_NONE		0

/**

 * The call will be routed as though it was initially sent via the phone used to

 * forward it. This feature is intended to support the situation in which the

 * forwarded call needs to be handled by the same connection fibril as any other

 * calls that were initially sent by the forwarder to the same destination. This

 * flag has no imapct on routing replies.

 */

#define IPC_FF_ROUTE_FROM_ME	(1 << 0)

/* System-specific methods - only through special syscalls

 * These methods have special behaviour

 */

/** Protocol for CONNECT - TO - ME 

 *

 * Calling process asks the callee to create a callback connection,

 * so that it can start initiating new messages.

 *

 * The protocol for negotiating is:

 * - sys_connect_to_me - sends a message IPC_M_CONNECT_TO_ME

 * - recipient         - upon receipt tries to allocate new phone

 *                       - if it fails, responds with ELIMIT

 *                     - passes call to userspace. If userspace

 *                       responds with error, phone is deallocated and

 *                       error is sent back to caller. Otherwise 

 *                       the call is accepted and the response is sent back.

 *                     - the allocated phoneid is passed to userspace 

 *                       (on the receiving side) as ARG5 of the call.

 */

#define IPC_M_CONNECT_TO_ME	1

/** Protocol for CONNECT - ME - TO

 *

 * Calling process asks the callee to create for him a new connection.

 * E.g. the caller wants a name server to connect him to print server.

 *

 * The protocol for negotiating is:

 * - sys_connect_me_to - send a synchronous message to name server

 *                       indicating that it wants to be connected to some

 *                       service

 *                     - arg1/2/3 are user specified, arg5 contains

 *                       address of the phone that should be connected

 *                       (TODO: it leaks to userspace)

 *  - recipient        -  if ipc_answer == 0, then accept connection

 *                     -  otherwise connection refused

 *                     -  recepient may forward message.

 *

 */

#define IPC_M_CONNECT_ME_TO	2

/** This message is sent to answerbox when the phone

 * is hung up

 */

#define IPC_M_PHONE_HUNGUP	3

/** Send as_area over IPC.

 * - ARG1 - source as_area base address

 * - ARG2 - size of source as_area (filled automatically by kernel)

 * - ARG3 - flags of the as_area being sent

 * 

 * on answer, the recipient must set:

 * - ARG1 - dst as_area base adress

 */

#define IPC_M_AS_AREA_SEND	4	

/** Receive as_area over IPC.

 * - ARG1 - destination as_area base address

 * - ARG2 - destination as_area size

 * - ARG3 - user defined argument

 * 

 * on answer, the recipient must set:

 *

 * - ARG1 - source as_area base address

 * - ARG2 - flags that will be used for sharing

 */

#define IPC_M_AS_AREA_RECV	5	

/** Send data to another address space over IPC.

 * - ARG1 - source address space virtual address

 * - ARG2 - size of data to be copied, may be overriden by the recipient

 *

 * on answer, the recipient must set:

 *

 * - ARG1 - final destination address space virtual address

 * - ARG2 - final size of data to be copied

 */

#define IPC_M_DATA_WRITE	6

/** Receive data from another address space over IPC.

 * - ARG1 - destination virtual address in the source address space

 * - ARG2 - size of data to be received, may be cropped by the recipient 

 *

 * on answer, the recipient must set:

 *

 * - ARG1 - source virtual address in the destination address space

 * - ARG2 - final size of data to be copied

 */

#define IPC_M_DATA_READ		7

/* Well-known methods */

#define IPC_M_LAST_SYSTEM	511

#define IPC_M_PING		512

/* User methods */

#define IPC_FIRST_USER_METHOD	1024

#ifdef KERNEL

#define IPC_MAX_PHONES  16

#include <synch/waitq.h>

struct answerbox;

struct task;

typedef enum {

	/** Phone is free and can be allocated */

	IPC_PHONE_FREE = 0,

	/** Phone is connecting somewhere */

	IPC_PHONE_CONNECTING,

	/** Phone is connected */

	IPC_PHONE_CONNECTED,

	/** Phone is hung up, waiting for answers to come */

	IPC_PHONE_HUNGUP,

	/** Phone was hungup from server */

	IPC_PHONE_SLAMMED

} ipc_phone_state_t;

/** Structure identifying phone (in TASK structure) */

typedef struct {

	SPINLOCK_DECLARE(lock);

	link_t link;

	struct answerbox *callee;

	ipc_phone_state_t state;

	atomic_t active_calls;

} phone_t;

typedef struct answerbox {

	SPINLOCK_DECLARE(lock);

	struct task *task;

	waitq_t wq;

	/** Phones connected to this answerbox. */

	link_t connected_phones;

	/** Received calls. */

	link_t calls;			

	link_t dispatched_calls;	/* Should be hash table in the future */

	/** Answered calls. */

	link_t answers;

	SPINLOCK_DECLARE(irq_lock);

	/** Notifications from IRQ handlers. */

	link_t irq_notifs;

	/** IRQs with notifications to this answerbox. */

	link_t irq_head;

} answerbox_t;

typedef struct {

	unative_t args[IPC_CALL_LEN];

	phone_t *phone;

} ipc_data_t;

typedef struct {

	link_t link;

	int flags;

	/** Identification of the caller. */

	struct task *sender;

	/** The caller box is different from sender->answerbox for synchronous

	 *  calls. */

	answerbox_t *callerbox;

	/** Private data to internal IPC. */

	unative_t priv;

	/** Data passed from/to userspace. */

	ipc_data_t data;

	/** Buffer for IPC_M_DATA_WRITE and IPC_M_DATA_READ. */

	uint8_t *buffer;

} call_t;

extern void ipc_init(void);

extern call_t * ipc_wait_for_call(answerbox_t *box, uint32_t usec, int flags);

extern void ipc_answer(answerbox_t *box, call_t *request);

extern int ipc_call(phone_t *phone, call_t *call);

extern void ipc_call_sync(phone_t *phone, call_t *request);

extern void ipc_phone_init(phone_t *phone);

extern void ipc_phone_connect(phone_t *phone, answerbox_t *box);

extern void ipc_call_free(call_t *call);

extern call_t * ipc_call_alloc(int flags);

extern void ipc_answerbox_init(answerbox_t *box);

extern void ipc_call_static_init(call_t *call);

extern void task_print_list(void);

extern int ipc_forward(call_t *call, phone_t *newphone, answerbox_t *oldbox,

    int mode);

extern void ipc_cleanup(void);

extern int ipc_phone_hangup(phone_t *phone);

extern void ipc_backsend_err(phone_t *phone, call_t *call, unative_t err);

extern void ipc_print_task(task_id_t taskid);

extern answerbox_t *ipc_phone_0;

#endif

#endif

/** @}

 */