/*
   * 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) 2004-2008 Silicon Graphics, Inc. All rights reserved.
   */
  
  /*
   * External Cross Partition (XP) structures and defines.
   */
  
  #ifndef _DRIVERS_MISC_SGIXP_XP_H
  #define _DRIVERS_MISC_SGIXP_XP_H
  
  #include <linux/mutex.h>
  
  #if defined CONFIG_X86_UV || defined CONFIG_IA64_SGI_UV
  #include <asm/uv/uv.h>
  #define is_uv()		is_uv_system()
  #endif
  
  #ifndef is_uv
  #define is_uv()		0
  #endif
  
  #if defined CONFIG_IA64
  #include <asm/sn/arch.h>	/* defines is_shub1() and is_shub2() */
  #define is_shub()	ia64_platform_is("sn2")
  #endif
  
  #ifndef is_shub1
  #define is_shub1()	0
  #endif
  
  #ifndef is_shub2
  #define is_shub2()	0
  #endif
  
  #ifndef is_shub
  #define is_shub()	0
  #endif
  
  #ifdef USE_DBUG_ON
  #define DBUG_ON(condition)	BUG_ON(condition)
  #else
  #define DBUG_ON(condition)
  #endif
  
  /*
   * Define the maximum number of partitions the system can possibly support.
   * It is based on 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_NPARTITIONS_SN2	64
  #define XP_MAX_NPARTITIONS_UV	256
  
  /*
   * 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.
   *
   * If the need for additional channels arises, one can simply increase
   * XPC_MAX_NCHANNELS accordingly. If the day should come where that number
   * exceeds the absolute MAXIMUM number of channels possible (eight), then one
   * will need to make changes to the XPC code to accommodate for this.
   *
   * The absolute maximum number of channels possible is limited to eight for
   * performance reasons on sn2 hardware. The internal cross partition structures
   * require sixteen bytes per channel, and eight allows all of this
   * interface-shared info to fit in one 128-byte cacheline.
   */
  #define XPC_MEM_CHANNEL		0	/* memory channel number */
  #define	XPC_NET_CHANNEL		1	/* network channel number */
  
  #define XPC_MAX_NCHANNELS	2	/* max #of channels allowed */
  
  #if XPC_MAX_NCHANNELS > 8
  #error	XPC_MAX_NCHANNELS exceeds absolute MAXIMUM possible.
  #endif
  
  /*
   * Define 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).
   */
  #define XPC_MSG_MAX_SIZE	128
  #define XPC_MSG_HDR_MAX_SIZE	16
  #define XPC_MSG_PAYLOAD_MAX_SIZE (XPC_MSG_MAX_SIZE - XPC_MSG_HDR_MAX_SIZE)
  
  #define XPC_MSG_SIZE(_payload_size) \
  				ALIGN(XPC_MSG_HDR_MAX_SIZE + (_payload_size), \
  				      is_uv() ? 64 : 128)
  
  
  /*
   * 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
   * xpUnknownReason, which must have the highest numerical value.)
   */
  enum xp_retval {
  	xpSuccess = 0,
  
  	xpNotConnected,		/*  1: channel is not connected */
  	xpConnected,		/*  2: channel connected (opened) */
  	xpRETIRED1,		/*  3: (formerly xpDisconnected) */
  
  	xpMsgReceived,		/*  4: message received */
  	xpMsgDelivered,		/*  5: message delivered and acknowledged */
  
  	xpRETIRED2,		/*  6: (formerly xpTransferFailed) */
  
  	xpNoWait,		/*  7: operation would require wait */
  	xpRetry,		/*  8: retry operation */
  	xpTimeout,		/*  9: timeout in xpc_allocate_msg_wait() */
  	xpInterrupted,		/* 10: interrupted wait */
  
  	xpUnequalMsgSizes,	/* 11: message size disparity between sides */
  	xpInvalidAddress,	/* 12: invalid address */
  
  	xpNoMemory,		/* 13: no memory available for XPC structures */
  	xpLackOfResources,	/* 14: insufficient resources for operation */
  	xpUnregistered,		/* 15: channel is not registered */
  	xpAlreadyRegistered,	/* 16: channel is already registered */
  
  	xpPartitionDown,	/* 17: remote partition is down */
  	xpNotLoaded,		/* 18: XPC module is not loaded */
  	xpUnloading,		/* 19: this side is unloading XPC module */
  
  	xpBadMagic,		/* 20: XPC MAGIC string not found */
  
  	xpReactivating,		/* 21: remote partition was reactivated */
  
  	xpUnregistering,	/* 22: this side is unregistering channel */
  	xpOtherUnregistering,	/* 23: other side is unregistering channel */
  
  	xpCloneKThread,		/* 24: cloning kernel thread */
  	xpCloneKThreadFailed,	/* 25: cloning kernel thread failed */
  
  	xpNoHeartbeat,		/* 26: remote partition has no heartbeat */
  
  	xpPioReadError,		/* 27: PIO read error */
  	xpPhysAddrRegFailed,	/* 28: registration of phys addr range failed */
  
  	xpRETIRED3,		/* 29: (formerly xpBteDirectoryError) */
  	xpRETIRED4,		/* 30: (formerly xpBtePoisonError) */
  	xpRETIRED5,		/* 31: (formerly xpBteWriteError) */
  	xpRETIRED6,		/* 32: (formerly xpBteAccessError) */
  	xpRETIRED7,		/* 33: (formerly xpBtePWriteError) */
  	xpRETIRED8,		/* 34: (formerly xpBtePReadError) */
  	xpRETIRED9,		/* 35: (formerly xpBteTimeOutError) */
  	xpRETIRED10,		/* 36: (formerly xpBteXtalkError) */
  	xpRETIRED11,		/* 37: (formerly xpBteNotAvailable) */
  	xpRETIRED12,		/* 38: (formerly xpBteUnmappedError) */
  
  	xpBadVersion,		/* 39: bad version number */
  	xpVarsNotSet,		/* 40: the XPC variables are not set up */
  	xpNoRsvdPageAddr,	/* 41: unable to get rsvd page's phys addr */
  	xpInvalidPartid,	/* 42: invalid partition ID */
  	xpLocalPartid,		/* 43: local partition ID */
  
  	xpOtherGoingDown,	/* 44: other side going down, reason unknown */
  	xpSystemGoingDown,	/* 45: system is going down, reason unknown */
  	xpSystemHalt,		/* 46: system is being halted */
  	xpSystemReboot,		/* 47: system is being rebooted */
  	xpSystemPoweroff,	/* 48: system is being powered off */
  
  	xpDisconnecting,	/* 49: channel disconnecting (closing) */
  
  	xpOpenCloseError,	/* 50: channel open/close protocol error */
  
  	xpDisconnected,		/* 51: channel disconnected (closed) */
  
  	xpBteCopyError,		/* 52: bte_copy() returned error */
  	xpSalError,		/* 53: sn SAL error */
  	xpRsvdPageNotSet,	/* 54: the reserved page is not set up */
  	xpPayloadTooBig,	/* 55: payload too large for message slot */
  
  	xpUnsupported,		/* 56: unsupported functionality or resource */
  	xpNeedMoreInfo,		/* 57: more info is needed by SAL */
  
  	xpGruCopyError,		/* 58: gru_copy_gru() returned error */
  	xpGruSendMqError,	/* 59: gru send message queue related error */
  
  	xpBadChannelNumber,	/* 60: invalid channel number */
  	xpBadMsgType,		/* 61: invalid message type */
  	xpBiosError,		/* 62: BIOS error */
  
  	xpUnknownReason		/* 63: unknown reason - must be last in enum */
  };
  
  /*
   * Define the callout function type used by XPC to update the user on
   * connection activity and state changes via the user function registered
   * by xpc_connect().
   *
   * Arguments:
   *
   *	reason - reason code.
   *	partid - partition ID associated with condition.
   *	ch_number - channel # associated with condition.
   *	data - pointer to optional data.
   *	key - pointer to optional user-defined value provided as the "key"
   *	      argument to xpc_connect().
   *
   * A reason code of xpConnected indicates that a connection has been
   * established to the specified partition on the specified channel. The data
   * argument indicates the max number of entries allowed in the message queue.
   *
   * A reason code of xpMsgReceived indicates that a XPC message arrived from
   * the specified partition on the specified channel. The data argument
   * specifies the address of the message's payload. The user must call
   * xpc_received() when finished with the payload.
   *
   * All other reason codes indicate failure. The data argmument is NULL.
   * When a failure reason code is received, one can assume that the channel
   * is not connected.
   */
  typedef void (*xpc_channel_func) (enum xp_retval reason, short partid,
  				  int ch_number, void *data, void *key);
  
  /*
   * Define the callout function type used by XPC to notify the user of
   * messages received and delivered via the user function registered by
   * xpc_send_notify().
   *
   * Arguments:
   *
   *	reason - reason code.
   *	partid - partition ID associated with condition.
   *	ch_number - channel # associated with condition.
   *	key - pointer to optional user-defined value provided as the "key"
   *	      argument to xpc_send_notify().
   *
   * A reason code of xpMsgDelivered indicates that the message was delivered
   * to the intended recipient and that they have acknowledged its receipt by
   * calling xpc_received().
   *
   * All other reason codes indicate failure.
   *
   * NOTE: The user defined function must be callable by an interrupt handler
   *       and thus cannot block.
   */
  typedef void (*xpc_notify_func) (enum xp_retval reason, short 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 entry_size;		/* message queue's message entry 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_send() or xpc_send_notify() flags */
  #define XPC_WAIT	0	/* wait flag */
  #define XPC_NOWAIT	1	/* no wait flag */
  
  struct xpc_interface {
  	void (*connect) (int);
  	void (*disconnect) (int);
  	enum xp_retval (*send) (short, int, u32, void *, u16);
  	enum xp_retval (*send_notify) (short, int, u32, void *, u16,
  					xpc_notify_func, void *);
  	void (*received) (short, int, void *);
  	enum xp_retval (*partid_to_nasids) (short, void *);
  };
  
  extern struct xpc_interface xpc_interface;
  
  extern void xpc_set_interface(void (*)(int),
  			      void (*)(int),
  			      enum xp_retval (*)(short, int, u32, void *, u16),
  			      enum xp_retval (*)(short, int, u32, void *, u16,
  						 xpc_notify_func, void *),
  			      void (*)(short, int, void *),
  			      enum xp_retval (*)(short, void *));
  extern void xpc_clear_interface(void);
  
  extern enum xp_retval xpc_connect(int, xpc_channel_func, void *, u16,
  				   u16, u32, u32);
  extern void xpc_disconnect(int);
  
  static inline enum xp_retval
  xpc_send(short partid, int ch_number, u32 flags, void *payload,
  	 u16 payload_size)
  {
  	return xpc_interface.send(partid, ch_number, flags, payload,
  				  payload_size);
  }
  
  static inline enum xp_retval
  xpc_send_notify(short partid, int ch_number, u32 flags, void *payload,
  		u16 payload_size, xpc_notify_func func, void *key)
  {
  	return xpc_interface.send_notify(partid, ch_number, flags, payload,
  					 payload_size, func, key);
  }
  
  static inline void
  xpc_received(short partid, int ch_number, void *payload)
  {
  	return xpc_interface.received(partid, ch_number, payload);
  }
  
  static inline enum xp_retval
  xpc_partid_to_nasids(short partid, void *nasids)
  {
  	return xpc_interface.partid_to_nasids(partid, nasids);
  }
  
  extern short xp_max_npartitions;
  extern short xp_partition_id;
  extern u8 xp_region_size;
  
  extern unsigned long (*xp_pa) (void *);
  extern unsigned long (*xp_socket_pa) (unsigned long);
  extern enum xp_retval (*xp_remote_memcpy) (unsigned long, const unsigned long,
  		       size_t);
  extern int (*xp_cpu_to_nasid) (int);
  extern enum xp_retval (*xp_expand_memprotect) (unsigned long, unsigned long);
  extern enum xp_retval (*xp_restrict_memprotect) (unsigned long, unsigned long);
  
  extern u64 xp_nofault_PIOR_target;
  extern int xp_nofault_PIOR(void *);
  extern int xp_error_PIOR(void);
  
  extern struct device *xp;
  extern enum xp_retval xp_init_sn2(void);
  extern enum xp_retval xp_init_uv(void);
  extern void xp_exit_sn2(void);
  extern void xp_exit_uv(void);
  
  #endif /* _DRIVERS_MISC_SGIXP_XP_H */