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 #include <asm/sn/bte.h>
  21
  22 #ifdef USE_DBUG_ON
  23 #define DBUG_ON(condition)      BUG_ON(condition)
  24 #else
  25 #define DBUG_ON(condition)
  26 #endif
  27
  28 /*
  29  * Define the maximum number of logically defined partitions the system
  30  * can support. It is constrained by the maximum number of hardware
  31  * partitionable regions. The term 'region' in this context refers to the
  32  * minimum number of nodes that can comprise an access protection grouping.
  33  * The access protection is in regards to memory, IPI and IOI.
  34  *
  35  * The maximum number of hardware partitionable regions is equal to the
  36  * maximum number of nodes in the entire system divided by the minimum number
  37  * of nodes that comprise an access protection grouping.
  38  */
  39 #define XP_MAX_PARTITIONS       64
  40
  41 /*
  42  * Define the number of u64s required to represent all the C-brick nasids
  43  * as a bitmap.  The cross-partition kernel modules deal only with
  44  * C-brick nasids, thus the need for bitmaps which don't account for
  45  * odd-numbered (non C-brick) nasids.
  46  */
  47 #define XP_MAX_PHYSNODE_ID      (MAX_NUMALINK_NODES / 2)
  48 #define XP_NASID_MASK_BYTES     ((XP_MAX_PHYSNODE_ID + 7) / 8)
  49 #define XP_NASID_MASK_WORDS     ((XP_MAX_PHYSNODE_ID + 63) / 64)
  50
  51 /*
  52  * Wrapper for bte_copy() that should it return a failure status will retry
  53  * the bte_copy() once in the hope that the failure was due to a temporary
  54  * aberration (i.e., the link going down temporarily).
  55  *
  56  *      src - physical address of the source of the transfer.
  57  *      vdst - virtual address of the destination of the transfer.
  58  *      len - number of bytes to transfer from source to destination.
  59  *      mode - see bte_copy() for definition.
  60  *      notification - see bte_copy() for definition.
  61  *
  62  * Note: xp_bte_copy() should never be called while holding a spinlock.
  63  */
  64 static inline bte_result_t
  65 xp_bte_copy(u64 src, u64 vdst, u64 len, u64 mode, void *notification)
  66 {
  67         bte_result_t ret;
  68         u64 pdst = ia64_tpa(vdst);
  69
  70         /*
  71          * Ensure that the physically mapped memory is contiguous.
  72          *
  73          * We do this by ensuring that the memory is from region 7 only.
  74          * If the need should arise to use memory from one of the other
  75          * regions, then modify the BUG_ON() statement to ensure that the
  76          * memory from that region is always physically contiguous.
  77          */
  78         BUG_ON(REGION_NUMBER(vdst) != RGN_KERNEL);
  79
  80         ret = bte_copy(src, pdst, len, mode, notification);
  81         if ((ret != BTE_SUCCESS) && BTE_ERROR_RETRY(ret)) {
  82                 if (!in_interrupt())
  83                         cond_resched();
  84
  85                 ret = bte_copy(src, pdst, len, mode, notification);
  86         }
  87
  88         return ret;
  89 }
  90
  91 /*
  92  * XPC establishes channel connections between the local partition and any
  93  * other partition that is currently up. Over these channels, kernel-level
  94  * `users' can communicate with their counterparts on the other partitions.
  95  *
  96  * The maxinum number of channels is limited to eight. For performance reasons,
  97  * the internal cross partition structures require sixteen bytes per channel,
  98  * and eight allows all of this interface-shared info to fit in one cache line.
  99  *
 100  * XPC_NCHANNELS reflects the total number of channels currently defined.
 101  * If the need for additional channels arises, one can simply increase
 102  * XPC_NCHANNELS accordingly. If the day should come where that number
 103  * exceeds the MAXIMUM number of channels allowed (eight), then one will need
 104  * to make changes to the XPC code to allow for this.
 105  */
 106 #define XPC_MEM_CHANNEL         0       /* memory channel number */
 107 #define XPC_NET_CHANNEL         1       /* network channel number */
 108
 109 #define XPC_NCHANNELS           2       /* #of defined channels */
 110 #define XPC_MAX_NCHANNELS       8       /* max #of channels allowed */
 111
 112 #if XPC_NCHANNELS > XPC_MAX_NCHANNELS
 113 #error  XPC_NCHANNELS exceeds MAXIMUM allowed.
 114 #endif
 115
 116 /*
 117  * The format of an XPC message is as follows:
 118  *
 119  *      +-------+--------------------------------+
 120  *      | flags |////////////////////////////////|
 121  *      +-------+--------------------------------+
 122  *      |             message #                  |
 123  *      +----------------------------------------+
 124  *      |     payload (user-defined message)     |
 125  *      |                                        |
 126  *                      :
 127  *      |                                        |
 128  *      +----------------------------------------+
 129  *
 130  * The size of the payload is defined by the user via xpc_connect(). A user-
 131  * defined message resides in the payload area.
 132  *
 133  * The user should have no dealings with the message header, but only the
 134  * message's payload. When a message entry is allocated (via xpc_allocate())
 135  * a pointer to the payload area is returned and not the actual beginning of
 136  * the XPC message. The user then constructs a message in the payload area
 137  * and passes that pointer as an argument on xpc_send() or xpc_send_notify().
 138  *
 139  * The size of a message entry (within a message queue) must be a cacheline
 140  * sized multiple in order to facilitate the BTE transfer of messages from one
 141  * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
 142  * that wants to fit as many msg entries as possible in a given memory size
 143  * (e.g. a memory page).
 144  */
 145 struct xpc_msg {
 146         u8 flags;               /* FOR XPC INTERNAL USE ONLY */
 147         u8 reserved[7];         /* FOR XPC INTERNAL USE ONLY */
 148         s64 number;             /* FOR XPC INTERNAL USE ONLY */
 149
 150         u64 payload;            /* user defined portion of message */
 151 };
 152
 153 #define XPC_MSG_PAYLOAD_OFFSET  (u64) (&((struct xpc_msg *)0)->payload)
 154 #define XPC_MSG_SIZE(_payload_size) \
 155                 L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))
 156
 157 /*
 158  * Define the return values and values passed to user's callout functions.
 159  * (It is important to add new value codes at the end just preceding
 160  * xpcUnknownReason, which must have the highest numerical value.)
 161  */
 162 enum xpc_retval {
 163         xpcSuccess = 0,
 164
 165         xpcNotConnected,        /*  1: channel is not connected */
 166         xpcConnected,           /*  2: channel connected (opened) */
 167         xpcRETIRED1,            /*  3: (formerly xpcDisconnected) */
 168
 169         xpcMsgReceived,         /*  4: message received */
 170         xpcMsgDelivered,        /*  5: message delivered and acknowledged */
 171
 172         xpcRETIRED2,            /*  6: (formerly xpcTransferFailed) */
 173
 174         xpcNoWait,              /*  7: operation would require wait */
 175         xpcRetry,               /*  8: retry operation */
 176         xpcTimeout,             /*  9: timeout in xpc_allocate_msg_wait() */
 177         xpcInterrupted,         /* 10: interrupted wait */
 178
 179         xpcUnequalMsgSizes,     /* 11: message size disparity between sides */
 180         xpcInvalidAddress,      /* 12: invalid address */
 181
 182         xpcNoMemory,            /* 13: no memory available for XPC structures */
 183         xpcLackOfResources,     /* 14: insufficient resources for operation */
 184         xpcUnregistered,        /* 15: channel is not registered */
 185         xpcAlreadyRegistered,   /* 16: channel is already registered */
 186
 187         xpcPartitionDown,       /* 17: remote partition is down */
 188         xpcNotLoaded,           /* 18: XPC module is not loaded */
 189         xpcUnloading,           /* 19: this side is unloading XPC module */
 190
 191         xpcBadMagic,            /* 20: XPC MAGIC string not found */
 192
 193         xpcReactivating,        /* 21: remote partition was reactivated */
 194
 195         xpcUnregistering,       /* 22: this side is unregistering channel */
 196         xpcOtherUnregistering,  /* 23: other side is unregistering channel */
 197
 198         xpcCloneKThread,        /* 24: cloning kernel thread */
 199         xpcCloneKThreadFailed,  /* 25: cloning kernel thread failed */
 200
 201         xpcNoHeartbeat,         /* 26: remote partition has no heartbeat */
 202
 203         xpcPioReadError,        /* 27: PIO read error */
 204         xpcPhysAddrRegFailed,   /* 28: registration of phys addr range failed */
 205
 206         xpcBteDirectoryError,   /* 29: maps to BTEFAIL_DIR */
 207         xpcBtePoisonError,      /* 30: maps to BTEFAIL_POISON */
 208         xpcBteWriteError,       /* 31: maps to BTEFAIL_WERR */
 209         xpcBteAccessError,      /* 32: maps to BTEFAIL_ACCESS */
 210         xpcBtePWriteError,      /* 33: maps to BTEFAIL_PWERR */
 211         xpcBtePReadError,       /* 34: maps to BTEFAIL_PRERR */
 212         xpcBteTimeOutError,     /* 35: maps to BTEFAIL_TOUT */
 213         xpcBteXtalkError,       /* 36: maps to BTEFAIL_XTERR */
 214         xpcBteNotAvailable,     /* 37: maps to BTEFAIL_NOTAVAIL */
 215         xpcBteUnmappedError,    /* 38: unmapped BTEFAIL_ error */
 216
 217         xpcBadVersion,          /* 39: bad version number */
 218         xpcVarsNotSet,          /* 40: the XPC variables are not set up */
 219         xpcNoRsvdPageAddr,      /* 41: unable to get rsvd page's phys addr */
 220         xpcInvalidPartid,       /* 42: invalid partition ID */
 221         xpcLocalPartid,         /* 43: local partition ID */
 222
 223         xpcOtherGoingDown,      /* 44: other side going down, reason unknown */
 224         xpcSystemGoingDown,     /* 45: system is going down, reason unknown */
 225         xpcSystemHalt,          /* 46: system is being halted */
 226         xpcSystemReboot,        /* 47: system is being rebooted */
 227         xpcSystemPoweroff,      /* 48: system is being powered off */
 228
 229         xpcDisconnecting,       /* 49: channel disconnecting (closing) */
 230
 231         xpcOpenCloseError,      /* 50: channel open/close protocol error */
 232
 233         xpcDisconnected,        /* 51: channel disconnected (closed) */
 234
 235         xpcBteSh2Start,         /* 52: BTE CRB timeout */
 236
 237                                 /* 53: 0x1 BTE Error Response Short */
 238         xpcBteSh2RspShort = xpcBteSh2Start + BTEFAIL_SH2_RESP_SHORT,
 239
 240                                 /* 54: 0x2 BTE Error Response Long */
 241         xpcBteSh2RspLong = xpcBteSh2Start + BTEFAIL_SH2_RESP_LONG,
 242
 243                                 /* 56: 0x4 BTE Error Response DSB */
 244         xpcBteSh2RspDSB = xpcBteSh2Start + BTEFAIL_SH2_RESP_DSP,
 245
 246                                 /* 60: 0x8 BTE Error Response Access */
 247         xpcBteSh2RspAccess = xpcBteSh2Start + BTEFAIL_SH2_RESP_ACCESS,
 248
 249                                 /* 68: 0x10 BTE Error CRB timeout */
 250         xpcBteSh2CRBTO = xpcBteSh2Start + BTEFAIL_SH2_CRB_TO,
 251
 252                                 /* 84: 0x20 BTE Error NACK limit */
 253         xpcBteSh2NACKLimit = xpcBteSh2Start + BTEFAIL_SH2_NACK_LIMIT,
 254
 255                                 /* 115: BTE end */
 256         xpcBteSh2End = xpcBteSh2Start + BTEFAIL_SH2_ALL,
 257
 258         xpcUnknownReason        /* 116: unknown reason - must be last in enum */
 259 };
 260
 261 /*
 262  * Define the callout function types used by XPC to update the user on
 263  * connection activity and state changes (via the user function registered by
 264  * xpc_connect()) and to notify them of messages received and delivered (via
 265  * the user function registered by xpc_send_notify()).
 266  *
 267  * The two function types are xpc_channel_func and xpc_notify_func and
 268  * both share the following arguments, with the exception of "data", which
 269  * only xpc_channel_func has.
 270  *
 271  * Arguments:
 272  *
 273  *      reason - reason code. (See following table.)
 274  *      partid - partition ID associated with condition.
 275  *      ch_number - channel # associated with condition.
 276  *      data - pointer to optional data. (See following table.)
 277  *      key - pointer to optional user-defined value provided as the "key"
 278  *            argument to xpc_connect() or xpc_send_notify().
 279  *
 280  * In the following table the "Optional Data" column applies to callouts made
 281  * to functions registered by xpc_connect(). A "NA" in that column indicates
 282  * that this reason code can be passed to functions registered by
 283  * xpc_send_notify() (i.e. they don't have data arguments).
 284  *
 285  * Also, the first three reason codes in the following table indicate
 286  * success, whereas the others indicate failure. When a failure reason code
 287  * is received, one can assume that the channel is not connected.
 288  *
 289  *
 290  * Reason Code          | Cause                          | Optional Data
 291  * =====================+================================+=====================
 292  * xpcConnected         | connection has been established| max #of entries
 293  *                      | to the specified partition on  | allowed in message
 294  *                      | the specified channel          | queue
 295  * ---------------------+--------------------------------+---------------------
 296  * xpcMsgReceived       | an XPC message arrived from    | address of payload
 297  *                      | the specified partition on the |
 298  *                      | specified channel              | [the user must call
 299  *                      |                                | xpc_received() when
 300  *                      |                                | finished with the
 301  *                      |                                | payload]
 302  * ---------------------+--------------------------------+---------------------
 303  * xpcMsgDelivered      | notification that the message  | NA
 304  *                      | was delivered to the intended  |
 305  *                      | recipient and that they have   |
 306  *                      | acknowledged its receipt by    |
 307  *                      | calling xpc_received()         |
 308  * =====================+================================+=====================
 309  * xpcUnequalMsgSizes   | can't connect to the specified | NULL
 310  *                      | partition on the specified     |
 311  *                      | channel because of mismatched  |
 312  *                      | message sizes                  |
 313  * ---------------------+--------------------------------+---------------------
 314  * xpcNoMemory          | insufficient memory avaiable   | NULL
 315  *                      | to allocate message queue      |
 316  * ---------------------+--------------------------------+---------------------
 317  * xpcLackOfResources   | lack of resources to create    | NULL
 318  *                      | the necessary kthreads to      |
 319  *                      | support the channel            |
 320  * ---------------------+--------------------------------+---------------------
 321  * xpcUnregistering     | this side's user has           | NULL or NA
 322  *                      | unregistered by calling        |
 323  *                      | xpc_disconnect()               |
 324  * ---------------------+--------------------------------+---------------------
 325  * xpcOtherUnregistering| the other side's user has      | NULL or NA
 326  *                      | unregistered by calling        |
 327  *                      | xpc_disconnect()               |
 328  * ---------------------+--------------------------------+---------------------
 329  * xpcNoHeartbeat       | the other side's XPC is no     | NULL or NA
 330  *                      | longer heartbeating            |
 331  *                      |                                |
 332  * ---------------------+--------------------------------+---------------------
 333  * xpcUnloading         | this side's XPC module is      | NULL or NA
 334  *                      | being unloaded                 |
 335  *                      |                                |
 336  * ---------------------+--------------------------------+---------------------
 337  * xpcOtherUnloading    | the other side's XPC module is | NULL or NA
 338  *                      | is being unloaded              |
 339  *                      |                                |
 340  * ---------------------+--------------------------------+---------------------
 341  * xpcPioReadError      | xp_nofault_PIOR() returned an  | NULL or NA
 342  *                      | error while sending an IPI     |
 343  *                      |                                |
 344  * ---------------------+--------------------------------+---------------------
 345  * xpcInvalidAddress    | the address either received or | NULL or NA
 346  *                      | sent by the specified partition|
 347  *                      | is invalid                     |
 348  * ---------------------+--------------------------------+---------------------
 349  * xpcBteNotAvailable   | attempt to pull data from the  | NULL or NA
 350  * xpcBtePoisonError    | specified partition over the   |
 351  * xpcBteWriteError     | specified channel via a        |
 352  * xpcBteAccessError    | bte_copy() failed              |
 353  * xpcBteTimeOutError   |                                |
 354  * xpcBteXtalkError     |                                |
 355  * xpcBteDirectoryError |                                |
 356  * xpcBteGenericError   |                                |
 357  * xpcBteUnmappedError  |                                |
 358  * ---------------------+--------------------------------+---------------------
 359  * xpcUnknownReason     | the specified channel to the   | NULL or NA
 360  *                      | specified partition was        |
 361  *                      | unavailable for unknown reasons|
 362  * =====================+================================+=====================
 363  */
 364
 365 typedef void (*xpc_channel_func) (enum xpc_retval reason, partid_t partid,
 366                                   int ch_number, void *data, void *key);
 367
 368 typedef void (*xpc_notify_func) (enum xpc_retval reason, partid_t partid,
 369                                  int ch_number, void *key);
 370
 371 /*
 372  * The following is a registration entry. There is a global array of these,
 373  * one per channel. It is used to record the connection registration made
 374  * by the users of XPC. As long as a registration entry exists, for any
 375  * partition that comes up, XPC will attempt to establish a connection on
 376  * that channel. Notification that a connection has been made will occur via
 377  * the xpc_channel_func function.
 378  *
 379  * The 'func' field points to the function to call when aynchronous
 380  * notification is required for such events as: a connection established/lost,
 381  * or an incoming message received, or an error condition encountered. A
 382  * non-NULL 'func' field indicates that there is an active registration for
 383  * the channel.
 384  */
 385 struct xpc_registration {
 386         struct mutex mutex;
 387         xpc_channel_func func;  /* function to call */
 388         void *key;              /* pointer to user's key */
 389         u16 nentries;           /* #of msg entries in local msg queue */
 390         u16 msg_size;           /* message queue's message size */
 391         u32 assigned_limit;     /* limit on #of assigned kthreads */
 392         u32 idle_limit;         /* limit on #of idle kthreads */
 393 } ____cacheline_aligned;
 394
 395 #define XPC_CHANNEL_REGISTERED(_c)      (xpc_registrations[_c].func != NULL)
 396
 397 /* the following are valid xpc_allocate() flags */
 398 #define XPC_WAIT        0       /* wait flag */
 399 #define XPC_NOWAIT      1       /* no wait flag */
 400
 401 struct xpc_interface {
 402         void (*connect) (int);
 403         void (*disconnect) (int);
 404         enum xpc_retval (*allocate) (partid_t, int, u32, void **);
 405         enum xpc_retval (*send) (partid_t, int, void *);
 406         enum xpc_retval (*send_notify) (partid_t, int, void *,
 407                                         xpc_notify_func, void *);
 408         void (*received) (partid_t, int, void *);
 409         enum xpc_retval (*partid_to_nasids) (partid_t, void *);
 410 };
 411
 412 extern struct xpc_interface xpc_interface;
 413
 414 extern void xpc_set_interface(void (*)(int),
 415                               void (*)(int),
 416                               enum xpc_retval (*)(partid_t, int, u32, void **),
 417                               enum xpc_retval (*)(partid_t, int, void *),
 418                               enum xpc_retval (*)(partid_t, int, void *,
 419                                                   xpc_notify_func, void *),
 420                               void (*)(partid_t, int, void *),
 421                               enum xpc_retval (*)(partid_t, void *));
 422 extern void xpc_clear_interface(void);
 423
 424 extern enum xpc_retval xpc_connect(int, xpc_channel_func, void *, u16,
 425                                    u16, u32, u32);
 426 extern void xpc_disconnect(int);
 427
 428 static inline enum xpc_retval
 429 xpc_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
 430 {
 431         return xpc_interface.allocate(partid, ch_number, flags, payload);
 432 }
 433
 434 static inline enum xpc_retval
 435 xpc_send(partid_t partid, int ch_number, void *payload)
 436 {
 437         return xpc_interface.send(partid, ch_number, payload);
 438 }
 439
 440 static inline enum xpc_retval
 441 xpc_send_notify(partid_t partid, int ch_number, void *payload,
 442                 xpc_notify_func func, void *key)
 443 {
 444         return xpc_interface.send_notify(partid, ch_number, payload, func, key);
 445 }
 446
 447 static inline void
 448 xpc_received(partid_t partid, int ch_number, void *payload)
 449 {
 450         return xpc_interface.received(partid, ch_number, payload);
 451 }
 452
 453 static inline enum xpc_retval
 454 xpc_partid_to_nasids(partid_t partid, void *nasids)
 455 {
 456         return xpc_interface.partid_to_nasids(partid, nasids);
 457 }
 458
 459 extern u64 xp_nofault_PIOR_target;
 460 extern int xp_nofault_PIOR(void *);
 461 extern int xp_error_PIOR(void);
 462
 463 #endif /* _DRIVERS_MISC_SGIXP_XP_H */