include/asm-ia64/sn/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) 2004-2005 Silicon Graphics, Inc. All rights reserved.
   7  */
   8
   9
  10 /*
  11  * External Cross Partition (XP) structures and defines.
  12  */
  13
  14
  15 #ifndef _ASM_IA64_SN_XP_H
  16 #define _ASM_IA64_SN_XP_H
  17
  18
  19 #include <linux/cache.h>
  20 #include <linux/hardirq.h>
  21 #include <asm/sn/types.h>
  22 #include <asm/sn/bte.h>
  23
  24
  25 #ifdef USE_DBUG_ON
  26 #define DBUG_ON(condition)      BUG_ON(condition)
  27 #else
  28 #define DBUG_ON(condition)
  29 #endif
  30
  31
  32 /*
  33  * Define the maximum number of logically defined partitions the system
  34  * can support. It is constrained by the maximum number of hardware
  35  * partitionable regions. The term 'region' in this context refers to the
  36  * minimum number of nodes that can comprise an access protection grouping.
  37  * The access protection is in regards to memory, IPI and IOI.
  38  *
  39  * The maximum number of hardware partitionable regions is equal to the
  40  * maximum number of nodes in the entire system divided by the minimum number
  41  * of nodes that comprise an access protection grouping.
  42  */
  43 #define XP_MAX_PARTITIONS       64
  44
  45
  46 /*
  47  * Define the number of u64s required to represent all the C-brick nasids
  48  * as a bitmap.  The cross-partition kernel modules deal only with
  49  * C-brick nasids, thus the need for bitmaps which don't account for
  50  * odd-numbered (non C-brick) nasids.
  51  */
  52 #define XP_MAX_PHYSNODE_ID      (MAX_PHYSNODE_ID / 2)
  53 #define XP_NASID_MASK_BYTES     ((XP_MAX_PHYSNODE_ID + 7) / 8)
  54 #define XP_NASID_MASK_WORDS     ((XP_MAX_PHYSNODE_ID + 63) / 64)
  55
  56
  57 /*
  58  * Wrapper for bte_copy() that should it return a failure status will retry
  59  * the bte_copy() once in the hope that the failure was due to a temporary
  60  * aberration (i.e., the link going down temporarily).
  61  *
  62  * See bte_copy for definition of the input parameters.
  63  *
  64  * Note: xp_bte_copy() should never be called while holding a spinlock.
  65  */
  66 static inline bte_result_t
  67 xp_bte_copy(u64 src, u64 dest, u64 len, u64 mode, void *notification)
  68 {
  69         bte_result_t ret;
  70
  71
  72         ret = bte_copy(src, dest, len, mode, notification);
  73
  74         if (ret != BTE_SUCCESS) {
  75                 if (!in_interrupt()) {
  76                         cond_resched();
  77                 }
  78                 ret = bte_copy(src, dest, len, mode, notification);
  79         }
  80
  81         return ret;
  82 }
  83
  84
  85 /*
  86  * XPC establishes channel connections between the local partition and any
  87  * other partition that is currently up. Over these channels, kernel-level
  88  * `users' can communicate with their counterparts on the other partitions.
  89  *
  90  * The maxinum number of channels is limited to eight. For performance reasons,
  91  * the internal cross partition structures require sixteen bytes per channel,
  92  * and eight allows all of this interface-shared info to fit in one cache line.
  93  *
  94  * XPC_NCHANNELS reflects the total number of channels currently defined.
  95  * If the need for additional channels arises, one can simply increase
  96  * XPC_NCHANNELS accordingly. If the day should come where that number
  97  * exceeds the MAXIMUM number of channels allowed (eight), then one will need
  98  * to make changes to the XPC code to allow for this.
  99  */
 100 #define XPC_MEM_CHANNEL         0       /* memory channel number */
 101 #define XPC_NET_CHANNEL         1       /* network channel number */
 102
 103 #define XPC_NCHANNELS           2       /* #of defined channels */
 104 #define XPC_MAX_NCHANNELS       8       /* max #of channels allowed */
 105
 106 #if XPC_NCHANNELS > XPC_MAX_NCHANNELS
 107 #error  XPC_NCHANNELS exceeds MAXIMUM allowed.
 108 #endif
 109
 110
 111 /*
 112  * The format of an XPC message is as follows:
 113  *
 114  *      +-------+--------------------------------+
 115  *      | flags |////////////////////////////////|
 116  *      +-------+--------------------------------+
 117  *      |             message #                  |
 118  *      +----------------------------------------+
 119  *      |     payload (user-defined message)     |
 120  *      |                                        |
 121  *                      :
 122  *      |                                        |
 123  *      +----------------------------------------+
 124  *
 125  * The size of the payload is defined by the user via xpc_connect(). A user-
 126  * defined message resides in the payload area.
 127  *
 128  * The user should have no dealings with the message header, but only the
 129  * message's payload. When a message entry is allocated (via xpc_allocate())
 130  * a pointer to the payload area is returned and not the actual beginning of
 131  * the XPC message. The user then constructs a message in the payload area
 132  * and passes that pointer as an argument on xpc_send() or xpc_send_notify().
 133  *
 134  * The size of a message entry (within a message queue) must be a cacheline
 135  * sized multiple in order to facilitate the BTE transfer of messages from one
 136  * message queue to another. A macro, XPC_MSG_SIZE(), is provided for the user
 137  * that wants to fit as many msg entries as possible in a given memory size
 138  * (e.g. a memory page).
 139  */
 140 struct xpc_msg {
 141         u8 flags;               /* FOR XPC INTERNAL USE ONLY */
 142         u8 reserved[7];         /* FOR XPC INTERNAL USE ONLY */
 143         s64 number;             /* FOR XPC INTERNAL USE ONLY */
 144
 145         u64 payload;            /* user defined portion of message */
 146 };
 147
 148
 149 #define XPC_MSG_PAYLOAD_OFFSET  (u64) (&((struct xpc_msg *)0)->payload)
 150 #define XPC_MSG_SIZE(_payload_size) \
 151                 L1_CACHE_ALIGN(XPC_MSG_PAYLOAD_OFFSET + (_payload_size))
 152
 153
 154 /*
 155  * Define the return values and values passed to user's callout functions.
 156  * (It is important to add new value codes at the end just preceding
 157  * xpcUnknownReason, which must have the highest numerical value.)
 158  */
 159 enum xpc_retval {
 160         xpcSuccess = 0,
 161
 162         xpcNotConnected,        /*  1: channel is not connected */
 163         xpcConnected,           /*  2: channel connected (opened) */
 164         xpcRETIRED1,            /*  3: (formerly xpcDisconnected) */
 165
 166         xpcMsgReceived,         /*  4: message received */
 167         xpcMsgDelivered,        /*  5: message delivered and acknowledged */
 168
 169         xpcRETIRED2,            /*  6: (formerly xpcTransferFailed) */
 170
 171         xpcNoWait,              /*  7: operation would require wait */
 172         xpcRetry,               /*  8: retry operation */
 173         xpcTimeout,             /*  9: timeout in xpc_allocate_msg_wait() */
 174         xpcInterrupted,         /* 10: interrupted wait */
 175
 176         xpcUnequalMsgSizes,     /* 11: message size disparity between sides */
 177         xpcInvalidAddress,      /* 12: invalid address */
 178
 179         xpcNoMemory,            /* 13: no memory available for XPC structures */
 180         xpcLackOfResources,     /* 14: insufficient resources for operation */
 181         xpcUnregistered,        /* 15: channel is not registered */
 182         xpcAlreadyRegistered,   /* 16: channel is already registered */
 183
 184         xpcPartitionDown,       /* 17: remote partition is down */
 185         xpcNotLoaded,           /* 18: XPC module is not loaded */
 186         xpcUnloading,           /* 19: this side is unloading XPC module */
 187
 188         xpcBadMagic,            /* 20: XPC MAGIC string not found */
 189
 190         xpcReactivating,        /* 21: remote partition was reactivated */
 191
 192         xpcUnregistering,       /* 22: this side is unregistering channel */
 193         xpcOtherUnregistering,  /* 23: other side is unregistering channel */
 194
 195         xpcCloneKThread,        /* 24: cloning kernel thread */
 196         xpcCloneKThreadFailed,  /* 25: cloning kernel thread failed */
 197
 198         xpcNoHeartbeat,         /* 26: remote partition has no heartbeat */
 199
 200         xpcPioReadError,        /* 27: PIO read error */
 201         xpcPhysAddrRegFailed,   /* 28: registration of phys addr range failed */
 202
 203         xpcBteDirectoryError,   /* 29: maps to BTEFAIL_DIR */
 204         xpcBtePoisonError,      /* 30: maps to BTEFAIL_POISON */
 205         xpcBteWriteError,       /* 31: maps to BTEFAIL_WERR */
 206         xpcBteAccessError,      /* 32: maps to BTEFAIL_ACCESS */
 207         xpcBtePWriteError,      /* 33: maps to BTEFAIL_PWERR */
 208         xpcBtePReadError,       /* 34: maps to BTEFAIL_PRERR */
 209         xpcBteTimeOutError,     /* 35: maps to BTEFAIL_TOUT */
 210         xpcBteXtalkError,       /* 36: maps to BTEFAIL_XTERR */
 211         xpcBteNotAvailable,     /* 37: maps to BTEFAIL_NOTAVAIL */
 212         xpcBteUnmappedError,    /* 38: unmapped BTEFAIL_ error */
 213
 214         xpcBadVersion,          /* 39: bad version number */
 215         xpcVarsNotSet,          /* 40: the XPC variables are not set up */
 216         xpcNoRsvdPageAddr,      /* 41: unable to get rsvd page's phys addr */
 217         xpcInvalidPartid,       /* 42: invalid partition ID */
 218         xpcLocalPartid,         /* 43: local partition ID */
 219
 220         xpcUnknownReason        /* 44: unknown reason -- must be last in list */
 221 };
 222
 223
 224 /*
 225  * Define the callout function types used by XPC to update the user on
 226  * connection activity and state changes (via the user function registered by
 227  * xpc_connect()) and to notify them of messages received and delivered (via
 228  * the user function registered by xpc_send_notify()).
 229  *
 230  * The two function types are xpc_channel_func and xpc_notify_func and
 231  * both share the following arguments, with the exception of "data", which
 232  * only xpc_channel_func has.
 233  *
 234  * Arguments:
 235  *
 236  *      reason - reason code. (See following table.)
 237  *      partid - partition ID associated with condition.
 238  *      ch_number - channel # associated with condition.
 239  *      data - pointer to optional data. (See following table.)
 240  *      key - pointer to optional user-defined value provided as the "key"
 241  *            argument to xpc_connect() or xpc_send_notify().
 242  *
 243  * In the following table the "Optional Data" column applies to callouts made
 244  * to functions registered by xpc_connect(). A "NA" in that column indicates
 245  * that this reason code can be passed to functions registered by
 246  * xpc_send_notify() (i.e. they don't have data arguments).
 247  *
 248  * Also, the first three reason codes in the following table indicate
 249  * success, whereas the others indicate failure. When a failure reason code
 250  * is received, one can assume that the channel is not connected.
 251  *
 252  *
 253  * Reason Code          | Cause                          | Optional Data
 254  * =====================+================================+=====================
 255  * xpcConnected         | connection has been established| max #of entries
 256  *                      | to the specified partition on  | allowed in message
 257  *                      | the specified channel          | queue
 258  * ---------------------+--------------------------------+---------------------
 259  * xpcMsgReceived       | an XPC message arrived from    | address of payload
 260  *                      | the specified partition on the |
 261  *                      | specified channel              | [the user must call
 262  *                      |                                | xpc_received() when
 263  *                      |                                | finished with the
 264  *                      |                                | payload]
 265  * ---------------------+--------------------------------+---------------------
 266  * xpcMsgDelivered      | notification that the message  | NA
 267  *                      | was delivered to the intended  |
 268  *                      | recipient and that they have   |
 269  *                      | acknowledged its receipt by    |
 270  *                      | calling xpc_received()         |
 271  * =====================+================================+=====================
 272  * xpcUnequalMsgSizes   | can't connect to the specified | NULL
 273  *                      | partition on the specified     |
 274  *                      | channel because of mismatched  |
 275  *                      | message sizes                  |
 276  * ---------------------+--------------------------------+---------------------
 277  * xpcNoMemory          | insufficient memory avaiable   | NULL
 278  *                      | to allocate message queue      |
 279  * ---------------------+--------------------------------+---------------------
 280  * xpcLackOfResources   | lack of resources to create    | NULL
 281  *                      | the necessary kthreads to      |
 282  *                      | support the channel            |
 283  * ---------------------+--------------------------------+---------------------
 284  * xpcUnregistering     | this side's user has           | NULL or NA
 285  *                      | unregistered by calling        |
 286  *                      | xpc_disconnect()               |
 287  * ---------------------+--------------------------------+---------------------
 288  * xpcOtherUnregistering| the other side's user has      | NULL or NA
 289  *                      | unregistered by calling        |
 290  *                      | xpc_disconnect()               |
 291  * ---------------------+--------------------------------+---------------------
 292  * xpcNoHeartbeat       | the other side's XPC is no     | NULL or NA
 293  *                      | longer heartbeating            |
 294  *                      |                                |
 295  * ---------------------+--------------------------------+---------------------
 296  * xpcUnloading         | this side's XPC module is      | NULL or NA
 297  *                      | being unloaded                 |
 298  *                      |                                |
 299  * ---------------------+--------------------------------+---------------------
 300  * xpcOtherUnloading    | the other side's XPC module is | NULL or NA
 301  *                      | is being unloaded              |
 302  *                      |                                |
 303  * ---------------------+--------------------------------+---------------------
 304  * xpcPioReadError      | xp_nofault_PIOR() returned an  | NULL or NA
 305  *                      | error while sending an IPI     |
 306  *                      |                                |
 307  * ---------------------+--------------------------------+---------------------
 308  * xpcInvalidAddress    | the address either received or | NULL or NA
 309  *                      | sent by the specified partition|
 310  *                      | is invalid                     |
 311  * ---------------------+--------------------------------+---------------------
 312  * xpcBteNotAvailable   | attempt to pull data from the  | NULL or NA
 313  * xpcBtePoisonError    | specified partition over the   |
 314  * xpcBteWriteError     | specified channel via a        |
 315  * xpcBteAccessError    | bte_copy() failed              |
 316  * xpcBteTimeOutError   |                                |
 317  * xpcBteXtalkError     |                                |
 318  * xpcBteDirectoryError |                                |
 319  * xpcBteGenericError   |                                |
 320  * xpcBteUnmappedError  |                                |
 321  * ---------------------+--------------------------------+---------------------
 322  * xpcUnknownReason     | the specified channel to the   | NULL or NA
 323  *                      | specified partition was        |
 324  *                      | unavailable for unknown reasons|
 325  * =====================+================================+=====================
 326  */
 327
 328 typedef void (*xpc_channel_func)(enum xpc_retval reason, partid_t partid,
 329                 int ch_number, void *data, void *key);
 330
 331 typedef void (*xpc_notify_func)(enum xpc_retval reason, partid_t partid,
 332                 int ch_number, void *key);
 333
 334
 335 /*
 336  * The following is a registration entry. There is a global array of these,
 337  * one per channel. It is used to record the connection registration made
 338  * by the users of XPC. As long as a registration entry exists, for any
 339  * partition that comes up, XPC will attempt to establish a connection on
 340  * that channel. Notification that a connection has been made will occur via
 341  * the xpc_channel_func function.
 342  *
 343  * The 'func' field points to the function to call when aynchronous
 344  * notification is required for such events as: a connection established/lost,
 345  * or an incomming message received, or an error condition encountered. A
 346  * non-NULL 'func' field indicates that there is an active registration for
 347  * the channel.
 348  */
 349 struct xpc_registration {
 350         struct semaphore sema;
 351         xpc_channel_func func;          /* function to call */
 352         void *key;                      /* pointer to user's key */
 353         u16 nentries;                   /* #of msg entries in local msg queue */
 354         u16 msg_size;                   /* message queue's message size */
 355         u32 assigned_limit;             /* limit on #of assigned kthreads */
 356         u32 idle_limit;                 /* limit on #of idle kthreads */
 357 } ____cacheline_aligned;
 358
 359
 360 #define XPC_CHANNEL_REGISTERED(_c)      (xpc_registrations[_c].func != NULL)
 361
 362
 363 /* the following are valid xpc_allocate() flags */
 364 #define XPC_WAIT        0               /* wait flag */
 365 #define XPC_NOWAIT      1               /* no wait flag */
 366
 367
 368 struct xpc_interface {
 369         void (*connect)(int);
 370         void (*disconnect)(int);
 371         enum xpc_retval (*allocate)(partid_t, int, u32, void **);
 372         enum xpc_retval (*send)(partid_t, int, void *);
 373         enum xpc_retval (*send_notify)(partid_t, int, void *,
 374                                                 xpc_notify_func, void *);
 375         void (*received)(partid_t, int, void *);
 376         enum xpc_retval (*partid_to_nasids)(partid_t, void *);
 377 };
 378
 379
 380 extern struct xpc_interface xpc_interface;
 381
 382 extern void xpc_set_interface(void (*)(int),
 383                 void (*)(int),
 384                 enum xpc_retval (*)(partid_t, int, u32, void **),
 385                 enum xpc_retval (*)(partid_t, int, void *),
 386                 enum xpc_retval (*)(partid_t, int, void *, xpc_notify_func,
 387                                                                 void *),
 388                 void (*)(partid_t, int, void *),
 389                 enum xpc_retval (*)(partid_t, void *));
 390 extern void xpc_clear_interface(void);
 391
 392
 393 extern enum xpc_retval xpc_connect(int, xpc_channel_func, void *, u16,
 394                                                 u16, u32, u32);
 395 extern void xpc_disconnect(int);
 396
 397 static inline enum xpc_retval
 398 xpc_allocate(partid_t partid, int ch_number, u32 flags, void **payload)
 399 {
 400         return xpc_interface.allocate(partid, ch_number, flags, payload);
 401 }
 402
 403 static inline enum xpc_retval
 404 xpc_send(partid_t partid, int ch_number, void *payload)
 405 {
 406         return xpc_interface.send(partid, ch_number, payload);
 407 }
 408
 409 static inline enum xpc_retval
 410 xpc_send_notify(partid_t partid, int ch_number, void *payload,
 411                         xpc_notify_func func, void *key)
 412 {
 413         return xpc_interface.send_notify(partid, ch_number, payload, func, key);
 414 }
 415
 416 static inline void
 417 xpc_received(partid_t partid, int ch_number, void *payload)
 418 {
 419         return xpc_interface.received(partid, ch_number, payload);
 420 }
 421
 422 static inline enum xpc_retval
 423 xpc_partid_to_nasids(partid_t partid, void *nasids)
 424 {
 425         return xpc_interface.partid_to_nasids(partid, nasids);
 426 }
 427
 428
 429 extern u64 xp_nofault_PIOR_target;
 430 extern int xp_nofault_PIOR(void *);
 431 extern int xp_error_PIOR(void);
 432
 433
 434 #endif /* _ASM_IA64_SN_XP_H */
 435