include/asm-ia64/sn/xp.h - kernel/msm - Gitiles

 /*
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
  * Copyright (C) 2004-2005 Silicon Graphics, Inc. All rights reserved.
  */


 /*
  * External Cross Partition (XP) structures and defines.
  */


 #ifndef _ASM_IA64_SN_XP_H
 #define _ASM_IA64_SN_XP_H


 #include <linux/cache.h>
 #include <linux/hardirq.h>
 #include <linux/mutex.h>
 #include <asm/sn/types.h>
 #include <asm/sn/bte.h>


 #ifdef USE_DBUG_ON
 #define DBUG_ON(condition)	BUG_ON(condition)
 #else
 #define DBUG_ON(condition)
 #endif


 /*
  * Define the maximum number of logically defined partitions the system
  * can support. It is constrained by the maximum number of hardware
  * partitionable regions. The term 'region' in this context refers to the
  * minimum number of nodes that can comprise an access protection grouping.
  * The access protection is in regards to memory, IPI and IOI.
  *
  * The maximum number of hardware partitionable regions is equal to the
  * maximum number of nodes in the entire system divided by the minimum number
  * of nodes that comprise an access protection grouping.
  */
 #define XP_MAX_PARTITIONS	64


 /*
  * Define the number of u64s required to represent all the C-brick nasids
  * as a bitmap.  The cross-partition kernel modules deal only with
  * C-brick nasids, thus the need for bitmaps which don't account for
  * odd-numbered (non C-brick) nasids.
  */
 #define XP_MAX_PHYSNODE_ID	(MAX_NUMALINK_NODES / 2)
 #define XP_NASID_MASK_BYTES	((XP_MAX_PHYSNODE_ID + 7) / 8)
 #define XP_NASID_MASK_WORDS	((XP_MAX_PHYSNODE_ID + 63) / 64)


 /*
  * Wrapper for bte_copy() that should it return a failure status will retry
  * the bte_copy() once in the hope that the failure was due to a temporary
  * aberration (i.e., the link going down temporarily).
  *
  * 	src - physical address of the source of the transfer.
  *	vdst - virtual address of the destination of the transfer.
  *	len - number of bytes to transfer from source to destination.
  *	mode - see bte_copy() for definition.
  *	notification - see bte_copy() for definition.
  *
  * Note: xp_bte_copy() should never be called while holding a spinlock.
  */
 static inline bte_result_t
 xp_bte_copy(u64 src, u64 vdst, u64 len, u64 mode, void *notification)
 {
 	bte_result_t ret;
 	u64 pdst = ia64_tpa(vdst);


 	/*
 	 * Ensure that the physically mapped memory is contiguous.
 	 *
 	 * We do this by ensuring that the memory is from region 7 only.
 	 * If the need should arise to use memory from one of the other
 	 * regions, then modify the BUG_ON() statement to ensure that the
 	 * memory from that region is always physically contiguous.
 	 */
 	BUG_ON(REGION_NUMBER(vdst) != RGN_KERNEL);

 	ret = bte_copy(src, pdst, len, mode, notification);
 	if ((ret != BTE_SUCCESS) && BTE_ERROR_RETRY(ret)) {
 		if (!in_interrupt()) {
 			cond_resched();
 		}
 		ret = bte_copy(src, pdst, len, mode, notification);
 	}

 	return ret;
 }


 /*
  * XPC establishes channel connections between the local partition and any
  * other partition that is currently up. Over these channels, kernel-level
  * `users' can communicate with their counterparts on the other partitions.
  *
  * The maxinum number of channels is limited to eight. For performance reasons,
  * the internal cross partition structures require sixteen bytes per channel,
  * and eight allows all of this interface-shared info to fit in one cache line.
  *
  * XPC_NCHANNELS reflects the total number of channels currently defined.
  * If the need for additional channels arises, one can simply increase
  * XPC_NCHANNELS accordingly. If the day should come where that number
  * exceeds the MAXIMUM number of channels allowed (eight), then one will need
  * to make changes to the XPC code to allow for this.
  */
 #define XPC_MEM_CHANNEL		0	/* memory channel number */
 #define	XPC_NET_CHANNEL		1	/* network channel number */

 #define	XPC_NCHANNELS		2	/* #of defined channels */
 #define XPC_MAX_NCHANNELS	8	/* max #of channels allowed */

 #if XPC_NCHANNELS > XPC_MAX_NCHANNELS
 #error	XPC_NCHANNELS exceeds MAXIMUM allowed.
 #endif


 /*
  * The format of an XPC message is as follows:
  *
  *      +-------+--------------------------------+
  *      | flags |////////////////////////////////|
  *      +-------+--------------------------------+
  *      |             message #                  |
  *      +----------------------------------------+
  *      |     payload (user-defined message)     |
  *      |                                        |
  *         		:
  *      |                                        |
  *      +----------------------------------------+
  *
  * The size of the payload is defined by the user via xpc_connect(). A user-
  * defined message resides in the payload area.
  *
  * The user should have no dealings with the message header, but only the
  * message's payload. When a message entry is allocated (via xpc_allocate())
  * a pointer to the payload area is returned and not the actual beginning of
  * the XPC message. The user then constructs a message in the payload area
  * and passes that pointer as an argument on xpc_send() or xpc_send_notify().
  *
  * The size of a message entry (within a message queue) must be a cacheline
  * sized multiple in order to facilitate the BTE transfer of messages from one
  * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
  * that wants to fit as many msg entries as possible in a given memory size
  * (e.g. a memory page).
  */
 struct xpc_msg {
 	u8 flags;		/* FOR XPC INTERNAL USE ONLY */
 	u8 reserved[7];		/* FOR XPC INTERNAL USE ONLY */
 	s64 number;		/* FOR XPC INTERNAL USE ONLY */

 	u64 payload;		/* user defined portion of message */
 };


 #define XPC_MSG_PAYLOAD_OFFSET	(u64) (&((struct xpc_msg *)0)->payload)
 #define XPC_MSG_SIZE(_payload_size) \
 		L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))


 /*
  * Define the return values and values passed to user's callout functions.
  * (It is important to add new value codes at the end just preceding
  * xpcUnknownReason, which must have the highest numerical value.)
  */
 enum xpc_retval {
 	xpcSuccess = 0,

 	xpcNotConnected,	/*  1: channel is not connected */
 	xpcConnected,		/*  2: channel connected (opened) */
 	xpcRETIRED1,		/*  3: (formerly xpcDisconnected) */

 	xpcMsgReceived,		/*  4: message received */
 	xpcMsgDelivered,	/*  5: message delivered and acknowledged */

 	xpcRETIRED2,		/*  6: (formerly xpcTransferFailed) */

 	xpcNoWait,		/*  7: operation would require wait */
 	xpcRetry,		/*  8: retry operation */
 	xpcTimeout,		/*  9: timeout in xpc_allocate_msg_wait() */
 	xpcInterrupted,		/* 10: interrupted wait */

 	xpcUnequalMsgSizes,	/* 11: message size disparity between sides */
 	xpcInvalidAddress,	/* 12: invalid address */

 	xpcNoMemory,		/* 13: no memory available for XPC structures */
 	xpcLackOfResources,	/* 14: insufficient resources for operation */
 	xpcUnregistered,	/* 15: channel is not registered */
 	xpcAlreadyRegistered,	/* 16: channel is already registered */

 	xpcPartitionDown,	/* 17: remote partition is down */
 	xpcNotLoaded,		/* 18: XPC module is not loaded */
 	xpcUnloading,		/* 19: this side is unloading XPC module */

 	xpcBadMagic,		/* 20: XPC MAGIC string not found */

 	xpcReactivating,	/* 21: remote partition was reactivated */

 	xpcUnregistering,	/* 22: this side is unregistering channel */
 	xpcOtherUnregistering,	/* 23: other side is unregistering channel */

 	xpcCloneKThread,	/* 24: cloning kernel thread */
 	xpcCloneKThreadFailed,	/* 25: cloning kernel thread failed */

 	xpcNoHeartbeat,		/* 26: remote partition has no heartbeat */

 	xpcPioReadError,	/* 27: PIO read error */
 	xpcPhysAddrRegFailed,	/* 28: registration of phys addr range failed */

 	xpcBteDirectoryError,	/* 29: maps to BTEFAIL_DIR */
 	xpcBtePoisonError,	/* 30: maps to BTEFAIL_POISON */
 	xpcBteWriteError,	/* 31: maps to BTEFAIL_WERR */
 	xpcBteAccessError,	/* 32: maps to BTEFAIL_ACCESS */
 	xpcBtePWriteError,	/* 33: maps to BTEFAIL_PWERR */
 	xpcBtePReadError,	/* 34: maps to BTEFAIL_PRERR */
 	xpcBteTimeOutError,	/* 35: maps to BTEFAIL_TOUT */
 	xpcBteXtalkError,	/* 36: maps to BTEFAIL_XTERR */
 	xpcBteNotAvailable,	/* 37: maps to BTEFAIL_NOTAVAIL */
 	xpcBteUnmappedError,	/* 38: unmapped BTEFAIL_ error */

 	xpcBadVersion,		/* 39: bad version number */
 	xpcVarsNotSet,		/* 40: the XPC variables are not set up */
 	xpcNoRsvdPageAddr,	/* 41: unable to get rsvd page's phys addr */
 	xpcInvalidPartid,	/* 42: invalid partition ID */
 	xpcLocalPartid,		/* 43: local partition ID */

 	xpcOtherGoingDown,	/* 44: other side going down, reason unknown */
 	xpcSystemGoingDown,	/* 45: system is going down, reason unknown */
 	xpcSystemHalt,		/* 46: system is being halted */
 	xpcSystemReboot,	/* 47: system is being rebooted */
 	xpcSystemPoweroff,	/* 48: system is being powered off */

 	xpcDisconnecting,	/* 49: channel disconnecting (closing) */

 	xpcOpenCloseError,	/* 50: channel open/close protocol error */

 	xpcDisconnected,	/* 51: channel disconnected (closed) */

 	xpcBteSh2Start,		/* 52: BTE CRB timeout */

 				/* 53: 0x1 BTE Error Response Short */
 	xpcBteSh2RspShort = xpcBteSh2Start + BTEFAIL_SH2_RESP_SHORT,

 				/* 54: 0x2 BTE Error Response Long */
 	xpcBteSh2RspLong = xpcBteSh2Start + BTEFAIL_SH2_RESP_LONG,

 				/* 56: 0x4 BTE Error Response DSB */
 	xpcBteSh2RspDSB = xpcBteSh2Start + BTEFAIL_SH2_RESP_DSP,

 				/* 60: 0x8 BTE Error Response Access */
 	xpcBteSh2RspAccess = xpcBteSh2Start + BTEFAIL_SH2_RESP_ACCESS,

 				/* 68: 0x10 BTE Error CRB timeout */
 	xpcBteSh2CRBTO = xpcBteSh2Start + BTEFAIL_SH2_CRB_TO,

 				/* 84: 0x20 BTE Error NACK limit */
 	xpcBteSh2NACKLimit = xpcBteSh2Start + BTEFAIL_SH2_NACK_LIMIT,

 				/* 115: BTE end */
 	xpcBteSh2End = xpcBteSh2Start + BTEFAIL_SH2_ALL,

 	xpcUnknownReason	/* 116: unknown reason -- must be last in list */
 };


 /*
  * Define the callout function types used by XPC to update the user on
  * connection activity and state changes (via the user function registered by
  * xpc_connect()) and to notify them of messages received and delivered (via
  * the user function registered by xpc_send_notify()).
  *
  * The two function types are xpc_channel_func and xpc_notify_func and
  * both share the following arguments, with the exception of "data", which
  * only xpc_channel_func has.
  *
  * Arguments:
  *
  *	reason - reason code. (See following table.)
  *	partid - partition ID associated with condition.
  *	ch_number - channel # associated with condition.
  *	data - pointer to optional data. (See following table.)
  *	key - pointer to optional user-defined value provided as the "key"
  *	      argument to xpc_connect() or xpc_send_notify().
  *
  * In the following table the "Optional Data" column applies to callouts made
  * to functions registered by xpc_connect(). A "NA" in that column indicates
  * that this reason code can be passed to functions registered by
  * xpc_send_notify() (i.e. they don't have data arguments).
  *
  * Also, the first three reason codes in the following table indicate
  * success, whereas the others indicate failure. When a failure reason code
  * is received, one can assume that the channel is not connected.
  *
  *
  * Reason Code          | Cause                          | Optional Data
  * =====================+================================+=====================
  * xpcConnected         | connection has been established| max #of entries
  *                      | to the specified partition on  | allowed in message
  *                      | the specified channel          | queue
  * ---------------------+--------------------------------+---------------------
  * xpcMsgReceived       | an XPC message arrived from    | address of payload
  *                      | the specified partition on the |
  *                      | specified channel              | [the user must call
  *                      |                                | xpc_received() when
  *                      |                                | finished with the
  *                      |                                | payload]
  * ---------------------+--------------------------------+---------------------
  * xpcMsgDelivered      | notification that the message  | NA
  *                      | was delivered to the intended  |
  *                      | recipient and that they have   |
  *                      | acknowledged its receipt by    |
  *                      | calling xpc_received()         |
  * =====================+================================+=====================
  * xpcUnequalMsgSizes   | can't connect to the specified | NULL
  *                      | partition on the specified     |
  *                      | channel because of mismatched  |
  *                      | message sizes                  |
  * ---------------------+--------------------------------+---------------------
  * xpcNoMemory          | insufficient memory avaiable   | NULL
  *                      | to allocate message queue      |
  * ---------------------+--------------------------------+---------------------
  * xpcLackOfResources   | lack of resources to create    | NULL
  *                      | the necessary kthreads to      |
  *                      | support the channel            |
  * ---------------------+--------------------------------+---------------------
  * xpcUnregistering     | this side's user has           | NULL or NA
  *                      | unregistered by calling        |
  *                      | xpc_disconnect()               |
  * ---------------------+--------------------------------+---------------------
  * xpcOtherUnregistering| the other side's user has      | NULL or NA
  *                      | unregistered by calling        |
  *                      | xpc_disconnect()               |
  * ---------------------+--------------------------------+---------------------
  * xpcNoHeartbeat       | the other side's XPC is no     | NULL or NA
  *                      | longer heartbeating            |
  *                      |                                |
  * ---------------------+--------------------------------+---------------------
  * xpcUnloading         | this side's XPC module is      | NULL or NA
  *                      | being unloaded                 |
  *                      |                                |
  * ---------------------+--------------------------------+---------------------
  * xpcOtherUnloading    | the other side's XPC module is | NULL or NA
  *                      | is being unloaded              |
  *                      |                                |
  * ---------------------+--------------------------------+---------------------
  * xpcPioReadError      | xp_nofault_PIOR() returned an  | NULL or NA
  *                      | error while sending an IPI     |
  *                      |                                |
  * ---------------------+--------------------------------+---------------------
  * xpcInvalidAddress    | the address either received or | NULL or NA
  *                      | sent by the specified partition|
  *                      | is invalid                     |
  * ---------------------+--------------------------------+---------------------
  * xpcBteNotAvailable   | attempt to pull data from the  | NULL or NA
  * xpcBtePoisonError    | specified partition over the   |
  * xpcBteWriteError     | specified channel via a        |
  * xpcBteAccessError    | bte_copy() failed              |
  * xpcBteTimeOutError   |                                |
  * xpcBteXtalkError     |                                |
  * xpcBteDirectoryError |                                |
  * xpcBteGenericError   |                                |
  * xpcBteUnmappedError  |                                |
  * ---------------------+--------------------------------+---------------------
  * xpcUnknownReason     | the specified channel to the   | NULL or NA
  *                      | specified partition was        |
  *                      | unavailable for unknown reasons|
  * =====================+================================+=====================
  */

 typedef void (*xpc_channel_func)(enum xpc_retval reason, partid_t partid,
 		int ch_number, void *data, void *key);

 typedef void (*xpc_notify_func)(enum xpc_retval reason, partid_t partid,
 		int ch_number, void *key);


 /*
  * The following is a registration entry. There is a global array of these,
  * one per channel. It is used to record the connection registration made
  * by the users of XPC. As long as a registration entry exists, for any
  * partition that comes up, XPC will attempt to establish a connection on
  * that channel. Notification that a connection has been made will occur via
  * the xpc_channel_func function.
  *
  * The 'func' field points to the function to call when aynchronous
  * notification is required for such events as: a connection established/lost,
  * or an incoming message received, or an error condition encountered. A
  * non-NULL 'func' field indicates that there is an active registration for
  * the channel.
  */
 struct xpc_registration {
 	struct mutex mutex;
 	xpc_channel_func func;		/* function to call */
 	void *key;			/* pointer to user's key */
 	u16 nentries;			/* #of msg entries in local msg queue */
 	u16 msg_size;			/* message queue's message size */
 	u32 assigned_limit;		/* limit on #of assigned kthreads */
 	u32 idle_limit;			/* limit on #of idle kthreads */
 } ____cacheline_aligned;


 #define XPC_CHANNEL_REGISTERED(_c)	(xpc_registrations[_c].func != NULL)


 /* the following are valid xpc_allocate() flags */
 #define XPC_WAIT	0		/* wait flag */
 #define XPC_NOWAIT	1		/* no wait flag */


 struct xpc_interface {
 	void (*connect)(int);
 	void (*disconnect)(int);
 	enum xpc_retval (*allocate)(partid_t, int, u32, void **);
 	enum xpc_retval (*send)(partid_t, int, void *);
 	enum xpc_retval (*send_notify)(partid_t, int, void *,
 						xpc_notify_func, void *);
 	void (*received)(partid_t, int, void *);
 	enum xpc_retval (*partid_to_nasids)(partid_t, void *);
 };


 extern struct xpc_interface xpc_interface;

 extern void xpc_set_interface(void (*)(int),
 		void (*)(int),
 		enum xpc_retval (*)(partid_t, int, u32, void **),
 		enum xpc_retval (*)(partid_t, int, void *),
 		enum xpc_retval (*)(partid_t, int, void *, xpc_notify_func,
 								void *),
 		void (*)(partid_t, int, void *),
 		enum xpc_retval (*)(partid_t, void *));
 extern void xpc_clear_interface(void);


 extern enum xpc_retval xpc_connect(int, xpc_channel_func, void *, u16,
 						u16, u32, u32);
 extern void xpc_disconnect(int);

 static inline enum xpc_retval
 xpc_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
 {
 	return xpc_interface.allocate(partid, ch_number, flags, payload);
 }

 static inline enum xpc_retval
 xpc_send(partid_t partid, int ch_number, void *payload)
 {
 	return xpc_interface.send(partid, ch_number, payload);
 }

 static inline enum xpc_retval
 xpc_send_notify(partid_t partid, int ch_number, void *payload,
 			xpc_notify_func func, void *key)
 {
 	return xpc_interface.send_notify(partid, ch_number, payload, func, key);
 }

 static inline void
 xpc_received(partid_t partid, int ch_number, void *payload)
 {
 	return xpc_interface.received(partid, ch_number, payload);
 }

 static inline enum xpc_retval
 xpc_partid_to_nasids(partid_t partid, void *nasids)
 {
 	return xpc_interface.partid_to_nasids(partid, nasids);
 }


 extern u64 xp_nofault_PIOR_target;
 extern int xp_nofault_PIOR(void *);
 extern int xp_error_PIOR(void);


 #endif /* _ASM_IA64_SN_XP_H */
	/*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file "COPYING" in the main directory of this archive
	* for more details.
	*
	* Copyright (C) 2004-2005 Silicon Graphics, Inc. All rights reserved.
	*/


	/*
	* External Cross Partition (XP) structures and defines.
	*/


	#ifndef _ASM_IA64_SN_XP_H
	#define _ASM_IA64_SN_XP_H


	#include <linux/cache.h>
	#include <linux/hardirq.h>
	#include <linux/mutex.h>
	#include <asm/sn/types.h>
	#include <asm/sn/bte.h>


	#ifdef USE_DBUG_ON
	#define DBUG_ON(condition) BUG_ON(condition)
	#else
	#define DBUG_ON(condition)
	#endif


	/*
	* Define the maximum number of logically defined partitions the system
	* can support. It is constrained by the maximum number of hardware
	* partitionable regions. The term 'region' in this context refers to the
	* minimum number of nodes that can comprise an access protection grouping.
	* The access protection is in regards to memory, IPI and IOI.
	*
	* The maximum number of hardware partitionable regions is equal to the
	* maximum number of nodes in the entire system divided by the minimum number
	* of nodes that comprise an access protection grouping.
	*/
	#define XP_MAX_PARTITIONS 64


	/*
	* Define the number of u64s required to represent all the C-brick nasids
	* as a bitmap. The cross-partition kernel modules deal only with
	* C-brick nasids, thus the need for bitmaps which don't account for
	* odd-numbered (non C-brick) nasids.
	*/
	#define XP_MAX_PHYSNODE_ID (MAX_NUMALINK_NODES / 2)
	#define XP_NASID_MASK_BYTES ((XP_MAX_PHYSNODE_ID + 7) / 8)
	#define XP_NASID_MASK_WORDS ((XP_MAX_PHYSNODE_ID + 63) / 64)


	/*
	* Wrapper for bte_copy() that should it return a failure status will retry
	* the bte_copy() once in the hope that the failure was due to a temporary
	* aberration (i.e., the link going down temporarily).
	*
	* src - physical address of the source of the transfer.
	* vdst - virtual address of the destination of the transfer.
	* len - number of bytes to transfer from source to destination.
	* mode - see bte_copy() for definition.
	* notification - see bte_copy() for definition.
	*
	* Note: xp_bte_copy() should never be called while holding a spinlock.
	*/
	static inline bte_result_t
	xp_bte_copy(u64 src, u64 vdst, u64 len, u64 mode, void *notification)
	{
	bte_result_t ret;
	u64 pdst = ia64_tpa(vdst);


	/*
	* Ensure that the physically mapped memory is contiguous.
	*
	* We do this by ensuring that the memory is from region 7 only.
	* If the need should arise to use memory from one of the other
	* regions, then modify the BUG_ON() statement to ensure that the
	* memory from that region is always physically contiguous.
	*/
	BUG_ON(REGION_NUMBER(vdst) != RGN_KERNEL);

	ret = bte_copy(src, pdst, len, mode, notification);
	if ((ret != BTE_SUCCESS) && BTE_ERROR_RETRY(ret)) {
	if (!in_interrupt()) {
	cond_resched();
	}
	ret = bte_copy(src, pdst, len, mode, notification);
	}

	return ret;
	}


	/*
	* XPC establishes channel connections between the local partition and any
	* other partition that is currently up. Over these channels, kernel-level
	* `users' can communicate with their counterparts on the other partitions.
	*
	* The maxinum number of channels is limited to eight. For performance reasons,
	* the internal cross partition structures require sixteen bytes per channel,
	* and eight allows all of this interface-shared info to fit in one cache line.
	*
	* XPC_NCHANNELS reflects the total number of channels currently defined.
	* If the need for additional channels arises, one can simply increase
	* XPC_NCHANNELS accordingly. If the day should come where that number
	* exceeds the MAXIMUM number of channels allowed (eight), then one will need
	* to make changes to the XPC code to allow for this.
	*/
	#define XPC_MEM_CHANNEL 0 /* memory channel number */
	#define XPC_NET_CHANNEL 1 /* network channel number */

	#define XPC_NCHANNELS 2 /* #of defined channels */
	#define XPC_MAX_NCHANNELS 8 /* max #of channels allowed */

	#if XPC_NCHANNELS > XPC_MAX_NCHANNELS
	#error XPC_NCHANNELS exceeds MAXIMUM allowed.
	#endif


	/*
	* The format of an XPC message is as follows:
	*
	* +-------+--------------------------------+
	* \| flags \|////////////////////////////////\|
	* +-------+--------------------------------+
	* \| message # \|
	* +----------------------------------------+
	* \| payload (user-defined message) \|
	* \| \|
	* :
	* \| \|
	* +----------------------------------------+
	*
	* The size of the payload is defined by the user via xpc_connect(). A user-
	* defined message resides in the payload area.
	*
	* The user should have no dealings with the message header, but only the
	* message's payload. When a message entry is allocated (via xpc_allocate())
	* a pointer to the payload area is returned and not the actual beginning of
	* the XPC message. The user then constructs a message in the payload area
	* and passes that pointer as an argument on xpc_send() or xpc_send_notify().
	*
	* The size of a message entry (within a message queue) must be a cacheline
	* sized multiple in order to facilitate the BTE transfer of messages from one
	* message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
	* that wants to fit as many msg entries as possible in a given memory size
	* (e.g. a memory page).
	*/
	struct xpc_msg {
	u8 flags; /* FOR XPC INTERNAL USE ONLY */
	u8 reserved[7]; /* FOR XPC INTERNAL USE ONLY */
	s64 number; /* FOR XPC INTERNAL USE ONLY */

	u64 payload; /* user defined portion of message */
	};


	#define XPC_MSG_PAYLOAD_OFFSET (u64) (&((struct xpc_msg *)0)->payload)
	#define XPC_MSG_SIZE(_payload_size) \
	L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))


	/*
	* Define the return values and values passed to user's callout functions.
	* (It is important to add new value codes at the end just preceding
	* xpcUnknownReason, which must have the highest numerical value.)
	*/
	enum xpc_retval {
	xpcSuccess = 0,

	xpcNotConnected, /* 1: channel is not connected */
	xpcConnected, /* 2: channel connected (opened) */
	xpcRETIRED1, /* 3: (formerly xpcDisconnected) */

	xpcMsgReceived, /* 4: message received */
	xpcMsgDelivered, /* 5: message delivered and acknowledged */

	xpcRETIRED2, /* 6: (formerly xpcTransferFailed) */

	xpcNoWait, /* 7: operation would require wait */
	xpcRetry, /* 8: retry operation */
	xpcTimeout, /* 9: timeout in xpc_allocate_msg_wait() */
	xpcInterrupted, /* 10: interrupted wait */

	xpcUnequalMsgSizes, /* 11: message size disparity between sides */
	xpcInvalidAddress, /* 12: invalid address */

	xpcNoMemory, /* 13: no memory available for XPC structures */
	xpcLackOfResources, /* 14: insufficient resources for operation */
	xpcUnregistered, /* 15: channel is not registered */
	xpcAlreadyRegistered, /* 16: channel is already registered */

	xpcPartitionDown, /* 17: remote partition is down */
	xpcNotLoaded, /* 18: XPC module is not loaded */
	xpcUnloading, /* 19: this side is unloading XPC module */

	xpcBadMagic, /* 20: XPC MAGIC string not found */

	xpcReactivating, /* 21: remote partition was reactivated */

	xpcUnregistering, /* 22: this side is unregistering channel */
	xpcOtherUnregistering, /* 23: other side is unregistering channel */

	xpcCloneKThread, /* 24: cloning kernel thread */
	xpcCloneKThreadFailed, /* 25: cloning kernel thread failed */

	xpcNoHeartbeat, /* 26: remote partition has no heartbeat */

	xpcPioReadError, /* 27: PIO read error */
	xpcPhysAddrRegFailed, /* 28: registration of phys addr range failed */

	xpcBteDirectoryError, /* 29: maps to BTEFAIL_DIR */
	xpcBtePoisonError, /* 30: maps to BTEFAIL_POISON */
	xpcBteWriteError, /* 31: maps to BTEFAIL_WERR */
	xpcBteAccessError, /* 32: maps to BTEFAIL_ACCESS */
	xpcBtePWriteError, /* 33: maps to BTEFAIL_PWERR */
	xpcBtePReadError, /* 34: maps to BTEFAIL_PRERR */
	xpcBteTimeOutError, /* 35: maps to BTEFAIL_TOUT */
	xpcBteXtalkError, /* 36: maps to BTEFAIL_XTERR */
	xpcBteNotAvailable, /* 37: maps to BTEFAIL_NOTAVAIL */
	xpcBteUnmappedError, /* 38: unmapped BTEFAIL_ error */

	xpcBadVersion, /* 39: bad version number */
	xpcVarsNotSet, /* 40: the XPC variables are not set up */
	xpcNoRsvdPageAddr, /* 41: unable to get rsvd page's phys addr */
	xpcInvalidPartid, /* 42: invalid partition ID */
	xpcLocalPartid, /* 43: local partition ID */

	xpcOtherGoingDown, /* 44: other side going down, reason unknown */
	xpcSystemGoingDown, /* 45: system is going down, reason unknown */
	xpcSystemHalt, /* 46: system is being halted */
	xpcSystemReboot, /* 47: system is being rebooted */
	xpcSystemPoweroff, /* 48: system is being powered off */

	xpcDisconnecting, /* 49: channel disconnecting (closing) */

	xpcOpenCloseError, /* 50: channel open/close protocol error */

	xpcDisconnected, /* 51: channel disconnected (closed) */

	xpcBteSh2Start, /* 52: BTE CRB timeout */

	/* 53: 0x1 BTE Error Response Short */
	xpcBteSh2RspShort = xpcBteSh2Start + BTEFAIL_SH2_RESP_SHORT,

	/* 54: 0x2 BTE Error Response Long */
	xpcBteSh2RspLong = xpcBteSh2Start + BTEFAIL_SH2_RESP_LONG,

	/* 56: 0x4 BTE Error Response DSB */
	xpcBteSh2RspDSB = xpcBteSh2Start + BTEFAIL_SH2_RESP_DSP,

	/* 60: 0x8 BTE Error Response Access */
	xpcBteSh2RspAccess = xpcBteSh2Start + BTEFAIL_SH2_RESP_ACCESS,

	/* 68: 0x10 BTE Error CRB timeout */
	xpcBteSh2CRBTO = xpcBteSh2Start + BTEFAIL_SH2_CRB_TO,

	/* 84: 0x20 BTE Error NACK limit */
	xpcBteSh2NACKLimit = xpcBteSh2Start + BTEFAIL_SH2_NACK_LIMIT,

	/* 115: BTE end */
	xpcBteSh2End = xpcBteSh2Start + BTEFAIL_SH2_ALL,

	xpcUnknownReason /* 116: unknown reason -- must be last in list */
	};


	/*
	* Define the callout function types used by XPC to update the user on
	* connection activity and state changes (via the user function registered by
	* xpc_connect()) and to notify them of messages received and delivered (via
	* the user function registered by xpc_send_notify()).
	*
	* The two function types are xpc_channel_func and xpc_notify_func and
	* both share the following arguments, with the exception of "data", which
	* only xpc_channel_func has.
	*
	* Arguments:
	*
	* reason - reason code. (See following table.)
	* partid - partition ID associated with condition.
	* ch_number - channel # associated with condition.
	* data - pointer to optional data. (See following table.)
	* key - pointer to optional user-defined value provided as the "key"
	* argument to xpc_connect() or xpc_send_notify().
	*
	* In the following table the "Optional Data" column applies to callouts made
	* to functions registered by xpc_connect(). A "NA" in that column indicates
	* that this reason code can be passed to functions registered by
	* xpc_send_notify() (i.e. they don't have data arguments).
	*
	* Also, the first three reason codes in the following table indicate
	* success, whereas the others indicate failure. When a failure reason code
	* is received, one can assume that the channel is not connected.
	*
	*
	* Reason Code \| Cause \| Optional Data
	* =====================+================================+=====================
	* xpcConnected \| connection has been established\| max #of entries
	* \| to the specified partition on \| allowed in message
	* \| the specified channel \| queue
	* ---------------------+--------------------------------+---------------------
	* xpcMsgReceived \| an XPC message arrived from \| address of payload
	* \| the specified partition on the \|
	* \| specified channel \| [the user must call
	* \| \| xpc_received() when
	* \| \| finished with the
	* \| \| payload]
	* ---------------------+--------------------------------+---------------------
	* xpcMsgDelivered \| notification that the message \| NA
	* \| was delivered to the intended \|
	* \| recipient and that they have \|
	* \| acknowledged its receipt by \|
	* \| calling xpc_received() \|
	* =====================+================================+=====================
	* xpcUnequalMsgSizes \| can't connect to the specified \| NULL
	* \| partition on the specified \|
	* \| channel because of mismatched \|
	* \| message sizes \|
	* ---------------------+--------------------------------+---------------------
	* xpcNoMemory \| insufficient memory avaiable \| NULL
	* \| to allocate message queue \|
	* ---------------------+--------------------------------+---------------------
	* xpcLackOfResources \| lack of resources to create \| NULL
	* \| the necessary kthreads to \|
	* \| support the channel \|
	* ---------------------+--------------------------------+---------------------
	* xpcUnregistering \| this side's user has \| NULL or NA
	* \| unregistered by calling \|
	* \| xpc_disconnect() \|
	* ---------------------+--------------------------------+---------------------
	* xpcOtherUnregistering\| the other side's user has \| NULL or NA
	* \| unregistered by calling \|
	* \| xpc_disconnect() \|
	* ---------------------+--------------------------------+---------------------
	* xpcNoHeartbeat \| the other side's XPC is no \| NULL or NA
	* \| longer heartbeating \|
	* \| \|
	* ---------------------+--------------------------------+---------------------
	* xpcUnloading \| this side's XPC module is \| NULL or NA
	* \| being unloaded \|
	* \| \|
	* ---------------------+--------------------------------+---------------------
	* xpcOtherUnloading \| the other side's XPC module is \| NULL or NA
	* \| is being unloaded \|
	* \| \|
	* ---------------------+--------------------------------+---------------------
	* xpcPioReadError \| xp_nofault_PIOR() returned an \| NULL or NA
	* \| error while sending an IPI \|
	* \| \|
	* ---------------------+--------------------------------+---------------------
	* xpcInvalidAddress \| the address either received or \| NULL or NA
	* \| sent by the specified partition\|
	* \| is invalid \|
	* ---------------------+--------------------------------+---------------------
	* xpcBteNotAvailable \| attempt to pull data from the \| NULL or NA
	* xpcBtePoisonError \| specified partition over the \|
	* xpcBteWriteError \| specified channel via a \|
	* xpcBteAccessError \| bte_copy() failed \|
	* xpcBteTimeOutError \| \|
	* xpcBteXtalkError \| \|
	* xpcBteDirectoryError \| \|
	* xpcBteGenericError \| \|
	* xpcBteUnmappedError \| \|
	* ---------------------+--------------------------------+---------------------
	* xpcUnknownReason \| the specified channel to the \| NULL or NA
	* \| specified partition was \|
	* \| unavailable for unknown reasons\|
	* =====================+================================+=====================
	*/

	typedef void (*xpc_channel_func)(enum xpc_retval reason, partid_t partid,
	int ch_number, void data, void key);

	typedef void (*xpc_notify_func)(enum xpc_retval reason, partid_t partid,
	int ch_number, void *key);


	/*
	* The following is a registration entry. There is a global array of these,
	* one per channel. It is used to record the connection registration made
	* by the users of XPC. As long as a registration entry exists, for any
	* partition that comes up, XPC will attempt to establish a connection on
	* that channel. Notification that a connection has been made will occur via
	* the xpc_channel_func function.
	*
	* The 'func' field points to the function to call when aynchronous
	* notification is required for such events as: a connection established/lost,
	* or an incoming message received, or an error condition encountered. A
	* non-NULL 'func' field indicates that there is an active registration for
	* the channel.
	*/
	struct xpc_registration {
	struct mutex mutex;
	xpc_channel_func func; /* function to call */
	void key; / pointer to user's key */
	u16 nentries; /* #of msg entries in local msg queue */
	u16 msg_size; /* message queue's message size */
	u32 assigned_limit; /* limit on #of assigned kthreads */
	u32 idle_limit; /* limit on #of idle kthreads */
	} ____cacheline_aligned;


	#define XPC_CHANNEL_REGISTERED(_c) (xpc_registrations[_c].func != NULL)


	/* the following are valid xpc_allocate() flags */
	#define XPC_WAIT 0 /* wait flag */
	#define XPC_NOWAIT 1 /* no wait flag */


	struct xpc_interface {
	void (*connect)(int);
	void (*disconnect)(int);
	enum xpc_retval (allocate)(partid_t, int, u32, void *);
	enum xpc_retval (send)(partid_t, int, void );
	enum xpc_retval (send_notify)(partid_t, int, void ,
	xpc_notify_func, void *);
	void (received)(partid_t, int, void );
	enum xpc_retval (partid_to_nasids)(partid_t, void );
	};


	extern struct xpc_interface xpc_interface;

	extern void xpc_set_interface(void (*)(int),
	void (*)(int),
	enum xpc_retval ()(partid_t, int, u32, void *),
	enum xpc_retval ()(partid_t, int, void ),
	enum xpc_retval ()(partid_t, int, void , xpc_notify_func,
	void *),
	void ()(partid_t, int, void ),
	enum xpc_retval ()(partid_t, void ));
	extern void xpc_clear_interface(void);


	extern enum xpc_retval xpc_connect(int, xpc_channel_func, void *, u16,
	u16, u32, u32);
	extern void xpc_disconnect(int);

	static inline enum xpc_retval
	xpc_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
	{
	return xpc_interface.allocate(partid, ch_number, flags, payload);
	}

	static inline enum xpc_retval
	xpc_send(partid_t partid, int ch_number, void *payload)
	{
	return xpc_interface.send(partid, ch_number, payload);
	}

	static inline enum xpc_retval
	xpc_send_notify(partid_t partid, int ch_number, void *payload,
	xpc_notify_func func, void *key)
	{
	return xpc_interface.send_notify(partid, ch_number, payload, func, key);
	}

	static inline void
	xpc_received(partid_t partid, int ch_number, void *payload)
	{
	return xpc_interface.received(partid, ch_number, payload);
	}

	static inline enum xpc_retval
	xpc_partid_to_nasids(partid_t partid, void *nasids)
	{
	return xpc_interface.partid_to_nasids(partid, nasids);
	}


	extern u64 xp_nofault_PIOR_target;
	extern int xp_nofault_PIOR(void *);
	extern int xp_error_PIOR(void);


	#endif /* _ASM_IA64_SN_XP_H */