drivers/misc/sgi-xp/xp.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2004-2008 Silicon Graphics, Inc. All rights reserved.
   7  */
   8
   9 /*
  10  * External Cross Partition (XP) structures and defines.
  11  */
  12
  13 #ifndef _DRIVERS_MISC_SGIXP_XP_H
  14 #define _DRIVERS_MISC_SGIXP_XP_H
  15
  16 #include <linux/cache.h>
  17 #include <linux/hardirq.h>
  18 #include <linux/mutex.h>
  19 #include <asm/sn/types.h>
  20 #ifdef CONFIG_IA64
  21 #include <asm/sn/arch.h>
  22 #endif
  23
  24 /* >>> Add this #define to some linux header file some day. */
  25 #define BYTES_PER_WORD  sizeof(void *)
  26
  27 #ifdef USE_DBUG_ON
  28 #define DBUG_ON(condition)      BUG_ON(condition)
  29 #else
  30 #define DBUG_ON(condition)
  31 #endif
  32
  33 #ifndef is_shub1
  34 #define is_shub1()      0
  35 #endif
  36
  37 #ifndef is_shub2
  38 #define is_shub2()      0
  39 #endif
  40
  41 #ifndef is_shub
  42 #define is_shub()       (is_shub1() || is_shub2())
  43 #endif
  44
  45 #ifndef is_uv
  46 #define is_uv()         0
  47 #endif
  48
  49 /*
  50  * Define the maximum number of partitions the system can possibly support.
  51  * It is based on the maximum number of hardware partitionable regions. The
  52  * term 'region' in this context refers to the minimum number of nodes that
  53  * can comprise an access protection grouping. The access protection is in
  54  * regards to memory, IPI and IOI.
  55  *
  56  * The maximum number of hardware partitionable regions is equal to the
  57  * maximum number of nodes in the entire system divided by the minimum number
  58  * of nodes that comprise an access protection grouping.
  59  */
  60 #define XP_MAX_NPARTITIONS_SN2  64
  61 #define XP_MAX_NPARTITIONS_UV   256
  62
  63 /*
  64  * Define the number of u64s required to represent all the C-brick nasids
  65  * as a bitmap.  The cross-partition kernel modules deal only with
  66  * C-brick nasids, thus the need for bitmaps which don't account for
  67  * odd-numbered (non C-brick) nasids.
  68  */
  69 #define XP_MAX_PHYSNODE_ID      (MAX_NUMALINK_NODES / 2)
  70 #define XP_NASID_MASK_BYTES     ((XP_MAX_PHYSNODE_ID + 7) / 8)
  71 #define XP_NASID_MASK_WORDS     ((XP_MAX_PHYSNODE_ID + 63) / 64)
  72
  73 /*
  74  * XPC establishes channel connections between the local partition and any
  75  * other partition that is currently up. Over these channels, kernel-level
  76  * `users' can communicate with their counterparts on the other partitions.
  77  *
  78 >>> The following described limitation of a max of eight channels possible
  79 >>> pertains only to ia64-sn2. THIS ISN'T TRUE SINCE I'M PLANNING TO JUST
  80 >>> TIE INTO THE EXISTING MECHANISM ONCE THE CHANNEL MESSAGES ARE RECEIVED.
  81 >>> THE 128-BYTE CACHELINE PERFORMANCE ISSUE IS TIED TO IA64-SN2.
  82  *
  83  * If the need for additional channels arises, one can simply increase
  84  * XPC_MAX_NCHANNELS accordingly. If the day should come where that number
  85  * exceeds the absolute MAXIMUM number of channels possible (eight), then one
  86  * will need to make changes to the XPC code to accommodate for this.
  87  *
  88  * The absolute maximum number of channels possible is currently limited to
  89  * eight for performance reasons. The internal cross partition structures
  90  * require sixteen bytes per channel, and eight allows all of this
  91  * interface-shared info to fit in one 128-byte cacheline.
  92  */
  93 #define XPC_MEM_CHANNEL         0       /* memory channel number */
  94 #define XPC_NET_CHANNEL         1       /* network channel number */
  95
  96 #define XPC_MAX_NCHANNELS       2       /* max #of channels allowed */
  97
  98 #if XPC_MAX_NCHANNELS > 8
  99 #error  XPC_MAX_NCHANNELS exceeds absolute MAXIMUM possible.
 100 #endif
 101
 102 /*
 103  * The format of an XPC message is as follows:
 104  *
 105  *      +-------+--------------------------------+
 106  *      | flags |////////////////////////////////|
 107  *      +-------+--------------------------------+
 108  *      |             message #                  |
 109  *      +----------------------------------------+
 110  *      |     payload (user-defined message)     |
 111  *      |                                        |
 112  *                      :
 113  *      |                                        |
 114  *      +----------------------------------------+
 115  *
 116  * The size of the payload is defined by the user via xpc_connect(). A user-
 117  * defined message resides in the payload area.
 118  *
 119  * The user should have no dealings with the message header, but only the
 120  * message's payload. When a message entry is allocated (via xpc_allocate())
 121  * a pointer to the payload area is returned and not the actual beginning of
 122  * the XPC message. The user then constructs a message in the payload area
 123  * and passes that pointer as an argument on xpc_send() or xpc_send_notify().
 124  *
 125  * The size of a message entry (within a message queue) must be a cacheline
 126  * sized multiple in order to facilitate the BTE transfer of messages from one
 127  * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
 128  * that wants to fit as many msg entries as possible in a given memory size
 129  * (e.g. a memory page).
 130  */
 131 struct xpc_msg {
 132         u8 flags;               /* FOR XPC INTERNAL USE ONLY */
 133         u8 reserved[7];         /* FOR XPC INTERNAL USE ONLY */
 134         s64 number;             /* FOR XPC INTERNAL USE ONLY */
 135
 136         u64 payload;            /* user defined portion of message */
 137 };
 138
 139 #define XPC_MSG_PAYLOAD_OFFSET  (u64) (&((struct xpc_msg *)0)->payload)
 140 #define XPC_MSG_SIZE(_payload_size) \
 141                 L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))
 142
 143 /*
 144  * Define the return values and values passed to user's callout functions.
 145  * (It is important to add new value codes at the end just preceding
 146  * xpUnknownReason, which must have the highest numerical value.)
 147  */
 148 enum xp_retval {
 149         xpSuccess = 0,
 150
 151         xpNotConnected,         /*  1: channel is not connected */
 152         xpConnected,            /*  2: channel connected (opened) */
 153         xpRETIRED1,             /*  3: (formerly xpDisconnected) */
 154
 155         xpMsgReceived,          /*  4: message received */
 156         xpMsgDelivered,         /*  5: message delivered and acknowledged */
 157
 158         xpRETIRED2,             /*  6: (formerly xpTransferFailed) */
 159
 160         xpNoWait,               /*  7: operation would require wait */
 161         xpRetry,                /*  8: retry operation */
 162         xpTimeout,              /*  9: timeout in xpc_allocate_msg_wait() */
 163         xpInterrupted,          /* 10: interrupted wait */
 164
 165         xpUnequalMsgSizes,      /* 11: message size disparity between sides */
 166         xpInvalidAddress,       /* 12: invalid address */
 167
 168         xpNoMemory,             /* 13: no memory available for XPC structures */
 169         xpLackOfResources,      /* 14: insufficient resources for operation */
 170         xpUnregistered,         /* 15: channel is not registered */
 171         xpAlreadyRegistered,    /* 16: channel is already registered */
 172
 173         xpPartitionDown,        /* 17: remote partition is down */
 174         xpNotLoaded,            /* 18: XPC module is not loaded */
 175         xpUnloading,            /* 19: this side is unloading XPC module */
 176
 177         xpBadMagic,             /* 20: XPC MAGIC string not found */
 178
 179         xpReactivating,         /* 21: remote partition was reactivated */
 180
 181         xpUnregistering,        /* 22: this side is unregistering channel */
 182         xpOtherUnregistering,   /* 23: other side is unregistering channel */
 183
 184         xpCloneKThread,         /* 24: cloning kernel thread */
 185         xpCloneKThreadFailed,   /* 25: cloning kernel thread failed */
 186
 187         xpNoHeartbeat,          /* 26: remote partition has no heartbeat */
 188
 189         xpPioReadError,         /* 27: PIO read error */
 190         xpPhysAddrRegFailed,    /* 28: registration of phys addr range failed */
 191
 192         xpRETIRED3,             /* 29: (formerly xpBteDirectoryError) */
 193         xpRETIRED4,             /* 30: (formerly xpBtePoisonError) */
 194         xpRETIRED5,             /* 31: (formerly xpBteWriteError) */
 195         xpRETIRED6,             /* 32: (formerly xpBteAccessError) */
 196         xpRETIRED7,             /* 33: (formerly xpBtePWriteError) */
 197         xpRETIRED8,             /* 34: (formerly xpBtePReadError) */
 198         xpRETIRED9,             /* 35: (formerly xpBteTimeOutError) */
 199         xpRETIRED10,            /* 36: (formerly xpBteXtalkError) */
 200         xpRETIRED11,            /* 37: (formerly xpBteNotAvailable) */
 201         xpRETIRED12,            /* 38: (formerly xpBteUnmappedError) */
 202
 203         xpBadVersion,           /* 39: bad version number */
 204         xpVarsNotSet,           /* 40: the XPC variables are not set up */
 205         xpNoRsvdPageAddr,       /* 41: unable to get rsvd page's phys addr */
 206         xpInvalidPartid,        /* 42: invalid partition ID */
 207         xpLocalPartid,          /* 43: local partition ID */
 208
 209         xpOtherGoingDown,       /* 44: other side going down, reason unknown */
 210         xpSystemGoingDown,      /* 45: system is going down, reason unknown */
 211         xpSystemHalt,           /* 46: system is being halted */
 212         xpSystemReboot,         /* 47: system is being rebooted */
 213         xpSystemPoweroff,       /* 48: system is being powered off */
 214
 215         xpDisconnecting,        /* 49: channel disconnecting (closing) */
 216
 217         xpOpenCloseError,       /* 50: channel open/close protocol error */
 218
 219         xpDisconnected,         /* 51: channel disconnected (closed) */
 220
 221         xpBteCopyError,         /* 52: bte_copy() returned error */
 222         xpSalError,             /* 53: sn SAL error */
 223
 224         xpUnsupported,          /* 54: unsupported functionality or resource */
 225         xpUnknownReason         /* 55: unknown reason - must be last in enum */
 226 };
 227
 228 /*
 229  * Define the callout function type used by XPC to update the user on
 230  * connection activity and state changes via the user function registered
 231  * by xpc_connect().
 232  *
 233  * Arguments:
 234  *
 235  *      reason - reason code.
 236  *      partid - partition ID associated with condition.
 237  *      ch_number - channel # associated with condition.
 238  *      data - pointer to optional data.
 239  *      key - pointer to optional user-defined value provided as the "key"
 240  *            argument to xpc_connect().
 241  *
 242  * A reason code of xpConnected indicates that a connection has been
 243  * established to the specified partition on the specified channel. The data
 244  * argument indicates the max number of entries allowed in the message queue.
 245  *
 246  * A reason code of xpMsgReceived indicates that a XPC message arrived from
 247  * the specified partition on the specified channel. The data argument
 248  * specifies the address of the message's payload. The user must call
 249  * xpc_received() when finished with the payload.
 250  *
 251  * All other reason codes indicate failure. The data argmument is NULL.
 252  * When a failure reason code is received, one can assume that the channel
 253  * is not connected.
 254  */
 255 typedef void (*xpc_channel_func) (enum xp_retval reason, short partid,
 256                                   int ch_number, void *data, void *key);
 257
 258 /*
 259  * Define the callout function type used by XPC to notify the user of
 260  * messages received and delivered via the user function registered by
 261  * xpc_send_notify().
 262  *
 263  * Arguments:
 264  *
 265  *      reason - reason code.
 266  *      partid - partition ID associated with condition.
 267  *      ch_number - channel # associated with condition.
 268  *      key - pointer to optional user-defined value provided as the "key"
 269  *            argument to xpc_send_notify().
 270  *
 271  * A reason code of xpMsgDelivered indicates that the message was delivered
 272  * to the intended recipient and that they have acknowledged its receipt by
 273  * calling xpc_received().
 274  *
 275  * All other reason codes indicate failure.
 276  */
 277 typedef void (*xpc_notify_func) (enum xp_retval reason, short partid,
 278                                  int ch_number, void *key);
 279
 280 /*
 281  * The following is a registration entry. There is a global array of these,
 282  * one per channel. It is used to record the connection registration made
 283  * by the users of XPC. As long as a registration entry exists, for any
 284  * partition that comes up, XPC will attempt to establish a connection on
 285  * that channel. Notification that a connection has been made will occur via
 286  * the xpc_channel_func function.
 287  *
 288  * The 'func' field points to the function to call when aynchronous
 289  * notification is required for such events as: a connection established/lost,
 290  * or an incoming message received, or an error condition encountered. A
 291  * non-NULL 'func' field indicates that there is an active registration for
 292  * the channel.
 293  */
 294 struct xpc_registration {
 295         struct mutex mutex;
 296         xpc_channel_func func;  /* function to call */
 297         void *key;              /* pointer to user's key */
 298         u16 nentries;           /* #of msg entries in local msg queue */
 299         u16 msg_size;           /* message queue's message size */
 300         u32 assigned_limit;     /* limit on #of assigned kthreads */
 301         u32 idle_limit;         /* limit on #of idle kthreads */
 302 } ____cacheline_aligned;
 303
 304 #define XPC_CHANNEL_REGISTERED(_c)      (xpc_registrations[_c].func != NULL)
 305
 306 /* the following are valid xpc_allocate() flags */
 307 #define XPC_WAIT        0       /* wait flag */
 308 #define XPC_NOWAIT      1       /* no wait flag */
 309
 310 struct xpc_interface {
 311         void (*connect) (int);
 312         void (*disconnect) (int);
 313         enum xp_retval (*allocate) (short, int, u32, void **);
 314         enum xp_retval (*send) (short, int, void *);
 315         enum xp_retval (*send_notify) (short, int, void *,
 316                                         xpc_notify_func, void *);
 317         void (*received) (short, int, void *);
 318         enum xp_retval (*partid_to_nasids) (short, void *);
 319 };
 320
 321 extern struct xpc_interface xpc_interface;
 322
 323 extern void xpc_set_interface(void (*)(int),
 324                               void (*)(int),
 325                               enum xp_retval (*)(short, int, u32, void **),
 326                               enum xp_retval (*)(short, int, void *),
 327                               enum xp_retval (*)(short, int, void *,
 328                                                   xpc_notify_func, void *),
 329                               void (*)(short, int, void *),
 330                               enum xp_retval (*)(short, void *));
 331 extern void xpc_clear_interface(void);
 332
 333 extern enum xp_retval xpc_connect(int, xpc_channel_func, void *, u16,
 334                                    u16, u32, u32);
 335 extern void xpc_disconnect(int);
 336
 337 static inline enum xp_retval
 338 xpc_allocate(short partid, int ch_number, u32 flags, void **payload)
 339 {
 340         return xpc_interface.allocate(partid, ch_number, flags, payload);
 341 }
 342
 343 static inline enum xp_retval
 344 xpc_send(short partid, int ch_number, void *payload)
 345 {
 346         return xpc_interface.send(partid, ch_number, payload);
 347 }
 348
 349 static inline enum xp_retval
 350 xpc_send_notify(short partid, int ch_number, void *payload,
 351                 xpc_notify_func func, void *key)
 352 {
 353         return xpc_interface.send_notify(partid, ch_number, payload, func, key);
 354 }
 355
 356 static inline void
 357 xpc_received(short partid, int ch_number, void *payload)
 358 {
 359         return xpc_interface.received(partid, ch_number, payload);
 360 }
 361
 362 static inline enum xp_retval
 363 xpc_partid_to_nasids(short partid, void *nasids)
 364 {
 365         return xpc_interface.partid_to_nasids(partid, nasids);
 366 }
 367
 368 extern short xp_max_npartitions;
 369
 370 extern enum xp_retval (*xp_remote_memcpy) (void *, const void *, size_t);
 371
 372 extern u64 xp_nofault_PIOR_target;
 373 extern int xp_nofault_PIOR(void *);
 374 extern int xp_error_PIOR(void);
 375
 376 extern struct device *xp;
 377 extern enum xp_retval xp_init_sn2(void);
 378 extern enum xp_retval xp_init_uv(void);
 379 extern void xp_exit_sn2(void);
 380 extern void xp_exit_uv(void);
 381
 382 #endif /* _DRIVERS_MISC_SGIXP_XP_H */