xref: /linux/drivers/misc/sgi-xp/xp.h (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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   * (C) Copyright 2020 Hewlett Packard Enterprise Development LP
7   * Copyright (C) 2004-2008 Silicon Graphics, Inc. All rights reserved.
8   */
9  
10  /*
11   * External Cross Partition (XP) structures and defines.
12   */
13  
14  #ifndef _DRIVERS_MISC_SGIXP_XP_H
15  #define _DRIVERS_MISC_SGIXP_XP_H
16  
17  #include <linux/mutex.h>
18  
19  #if defined CONFIG_X86_UV
20  #include <asm/uv/uv.h>
21  #endif
22  
23  #ifdef USE_DBUG_ON
24  #define DBUG_ON(condition)	BUG_ON(condition)
25  #else
26  #define DBUG_ON(condition)
27  #endif
28  
29  /*
30   * Define the maximum number of partitions the system can possibly support.
31   * It is based on the maximum number of hardware partitionable regions. The
32   * term 'region' in this context refers to the minimum number of nodes that
33   * can comprise an access protection grouping. The access protection is in
34   * regards to memory, IPI and IOI.
35   *
36   * The maximum number of hardware partitionable regions is equal to the
37   * maximum number of nodes in the entire system divided by the minimum number
38   * of nodes that comprise an access protection grouping.
39   */
40  #define XP_MAX_NPARTITIONS_SN2	64
41  #define XP_MAX_NPARTITIONS_UV	256
42  
43  /*
44   * XPC establishes channel connections between the local partition and any
45   * other partition that is currently up. Over these channels, kernel-level
46   * `users' can communicate with their counterparts on the other partitions.
47   *
48   * If the need for additional channels arises, one can simply increase
49   * XPC_MAX_NCHANNELS accordingly. If the day should come where that number
50   * exceeds the absolute MAXIMUM number of channels possible (eight), then one
51   * will need to make changes to the XPC code to accommodate for this.
52   *
53   * The absolute maximum number of channels possible is limited to eight for
54   * performance reasons on sn2 hardware. The internal cross partition structures
55   * require sixteen bytes per channel, and eight allows all of this
56   * interface-shared info to fit in one 128-byte cacheline.
57   */
58  #define XPC_MEM_CHANNEL		0	/* memory channel number */
59  #define	XPC_NET_CHANNEL		1	/* network channel number */
60  
61  #define XPC_MAX_NCHANNELS	2	/* max #of channels allowed */
62  
63  #if XPC_MAX_NCHANNELS > 8
64  #error	XPC_MAX_NCHANNELS exceeds absolute MAXIMUM possible.
65  #endif
66  
67  /*
68   * Define macro, XPC_MSG_SIZE(), is provided for the user
69   * that wants to fit as many msg entries as possible in a given memory size
70   * (e.g. a memory page).
71   */
72  #define XPC_MSG_MAX_SIZE	128
73  #define XPC_MSG_HDR_MAX_SIZE	16
74  #define XPC_MSG_PAYLOAD_MAX_SIZE (XPC_MSG_MAX_SIZE - XPC_MSG_HDR_MAX_SIZE)
75  
76  #define XPC_MSG_SIZE(_payload_size) \
77  				ALIGN(XPC_MSG_HDR_MAX_SIZE + (_payload_size), \
78  				      is_uv_system() ? 64 : 128)
79  
80  
81  /*
82   * Define the return values and values passed to user's callout functions.
83   * (It is important to add new value codes at the end just preceding
84   * xpUnknownReason, which must have the highest numerical value.)
85   */
86  enum xp_retval {
87  	xpSuccess = 0,
88  
89  	xpNotConnected,		/*  1: channel is not connected */
90  	xpConnected,		/*  2: channel connected (opened) */
91  	xpRETIRED1,		/*  3: (formerly xpDisconnected) */
92  
93  	xpMsgReceived,		/*  4: message received */
94  	xpMsgDelivered,		/*  5: message delivered and acknowledged */
95  
96  	xpRETIRED2,		/*  6: (formerly xpTransferFailed) */
97  
98  	xpNoWait,		/*  7: operation would require wait */
99  	xpRetry,		/*  8: retry operation */
100  	xpTimeout,		/*  9: timeout in xpc_allocate_msg_wait() */
101  	xpInterrupted,		/* 10: interrupted wait */
102  
103  	xpUnequalMsgSizes,	/* 11: message size disparity between sides */
104  	xpInvalidAddress,	/* 12: invalid address */
105  
106  	xpNoMemory,		/* 13: no memory available for XPC structures */
107  	xpLackOfResources,	/* 14: insufficient resources for operation */
108  	xpUnregistered,		/* 15: channel is not registered */
109  	xpAlreadyRegistered,	/* 16: channel is already registered */
110  
111  	xpPartitionDown,	/* 17: remote partition is down */
112  	xpNotLoaded,		/* 18: XPC module is not loaded */
113  	xpUnloading,		/* 19: this side is unloading XPC module */
114  
115  	xpBadMagic,		/* 20: XPC MAGIC string not found */
116  
117  	xpReactivating,		/* 21: remote partition was reactivated */
118  
119  	xpUnregistering,	/* 22: this side is unregistering channel */
120  	xpOtherUnregistering,	/* 23: other side is unregistering channel */
121  
122  	xpCloneKThread,		/* 24: cloning kernel thread */
123  	xpCloneKThreadFailed,	/* 25: cloning kernel thread failed */
124  
125  	xpNoHeartbeat,		/* 26: remote partition has no heartbeat */
126  
127  	xpPioReadError,		/* 27: PIO read error */
128  	xpPhysAddrRegFailed,	/* 28: registration of phys addr range failed */
129  
130  	xpRETIRED3,		/* 29: (formerly xpBteDirectoryError) */
131  	xpRETIRED4,		/* 30: (formerly xpBtePoisonError) */
132  	xpRETIRED5,		/* 31: (formerly xpBteWriteError) */
133  	xpRETIRED6,		/* 32: (formerly xpBteAccessError) */
134  	xpRETIRED7,		/* 33: (formerly xpBtePWriteError) */
135  	xpRETIRED8,		/* 34: (formerly xpBtePReadError) */
136  	xpRETIRED9,		/* 35: (formerly xpBteTimeOutError) */
137  	xpRETIRED10,		/* 36: (formerly xpBteXtalkError) */
138  	xpRETIRED11,		/* 37: (formerly xpBteNotAvailable) */
139  	xpRETIRED12,		/* 38: (formerly xpBteUnmappedError) */
140  
141  	xpBadVersion,		/* 39: bad version number */
142  	xpVarsNotSet,		/* 40: the XPC variables are not set up */
143  	xpNoRsvdPageAddr,	/* 41: unable to get rsvd page's phys addr */
144  	xpInvalidPartid,	/* 42: invalid partition ID */
145  	xpLocalPartid,		/* 43: local partition ID */
146  
147  	xpOtherGoingDown,	/* 44: other side going down, reason unknown */
148  	xpSystemGoingDown,	/* 45: system is going down, reason unknown */
149  	xpSystemHalt,		/* 46: system is being halted */
150  	xpSystemReboot,		/* 47: system is being rebooted */
151  	xpSystemPoweroff,	/* 48: system is being powered off */
152  
153  	xpDisconnecting,	/* 49: channel disconnecting (closing) */
154  
155  	xpOpenCloseError,	/* 50: channel open/close protocol error */
156  
157  	xpDisconnected,		/* 51: channel disconnected (closed) */
158  
159  	xpBteCopyError,		/* 52: bte_copy() returned error */
160  	xpSalError,		/* 53: sn SAL error */
161  	xpRsvdPageNotSet,	/* 54: the reserved page is not set up */
162  	xpPayloadTooBig,	/* 55: payload too large for message slot */
163  
164  	xpUnsupported,		/* 56: unsupported functionality or resource */
165  	xpNeedMoreInfo,		/* 57: more info is needed by SAL */
166  
167  	xpGruCopyError,		/* 58: gru_copy_gru() returned error */
168  	xpGruSendMqError,	/* 59: gru send message queue related error */
169  
170  	xpBadChannelNumber,	/* 60: invalid channel number */
171  	xpBadMsgType,		/* 61: invalid message type */
172  	xpBiosError,		/* 62: BIOS error */
173  
174  	xpUnknownReason		/* 63: unknown reason - must be last in enum */
175  };
176  
177  /*
178   * Define the callout function type used by XPC to update the user on
179   * connection activity and state changes via the user function registered
180   * by xpc_connect().
181   *
182   * Arguments:
183   *
184   *	reason - reason code.
185   *	partid - partition ID associated with condition.
186   *	ch_number - channel # associated with condition.
187   *	data - pointer to optional data.
188   *	key - pointer to optional user-defined value provided as the "key"
189   *	      argument to xpc_connect().
190   *
191   * A reason code of xpConnected indicates that a connection has been
192   * established to the specified partition on the specified channel. The data
193   * argument indicates the max number of entries allowed in the message queue.
194   *
195   * A reason code of xpMsgReceived indicates that a XPC message arrived from
196   * the specified partition on the specified channel. The data argument
197   * specifies the address of the message's payload. The user must call
198   * xpc_received() when finished with the payload.
199   *
200   * All other reason codes indicate failure. The data argmument is NULL.
201   * When a failure reason code is received, one can assume that the channel
202   * is not connected.
203   */
204  typedef void (*xpc_channel_func) (enum xp_retval reason, short partid,
205  				  int ch_number, void *data, void *key);
206  
207  /*
208   * Define the callout function type used by XPC to notify the user of
209   * messages received and delivered via the user function registered by
210   * xpc_send_notify().
211   *
212   * Arguments:
213   *
214   *	reason - reason code.
215   *	partid - partition ID associated with condition.
216   *	ch_number - channel # associated with condition.
217   *	key - pointer to optional user-defined value provided as the "key"
218   *	      argument to xpc_send_notify().
219   *
220   * A reason code of xpMsgDelivered indicates that the message was delivered
221   * to the intended recipient and that they have acknowledged its receipt by
222   * calling xpc_received().
223   *
224   * All other reason codes indicate failure.
225   *
226   * NOTE: The user defined function must be callable by an interrupt handler
227   *       and thus cannot block.
228   */
229  typedef void (*xpc_notify_func) (enum xp_retval reason, short partid,
230  				 int ch_number, void *key);
231  
232  /*
233   * The following is a registration entry. There is a global array of these,
234   * one per channel. It is used to record the connection registration made
235   * by the users of XPC. As long as a registration entry exists, for any
236   * partition that comes up, XPC will attempt to establish a connection on
237   * that channel. Notification that a connection has been made will occur via
238   * the xpc_channel_func function.
239   *
240   * The 'func' field points to the function to call when aynchronous
241   * notification is required for such events as: a connection established/lost,
242   * or an incoming message received, or an error condition encountered. A
243   * non-NULL 'func' field indicates that there is an active registration for
244   * the channel.
245   */
246  struct xpc_registration {
247  	struct mutex mutex;
248  	xpc_channel_func func;	/* function to call */
249  	void *key;		/* pointer to user's key */
250  	u16 nentries;		/* #of msg entries in local msg queue */
251  	u16 entry_size;		/* message queue's message entry size */
252  	u32 assigned_limit;	/* limit on #of assigned kthreads */
253  	u32 idle_limit;		/* limit on #of idle kthreads */
254  } ____cacheline_aligned;
255  
256  #define XPC_CHANNEL_REGISTERED(_c)	(xpc_registrations[_c].func != NULL)
257  
258  /* the following are valid xpc_send() or xpc_send_notify() flags */
259  #define XPC_WAIT	0	/* wait flag */
260  #define XPC_NOWAIT	1	/* no wait flag */
261  
262  struct xpc_interface {
263  	void (*connect) (int);
264  	void (*disconnect) (int);
265  	enum xp_retval (*send) (short, int, u32, void *, u16);
266  	enum xp_retval (*send_notify) (short, int, u32, void *, u16,
267  					xpc_notify_func, void *);
268  	void (*received) (short, int, void *);
269  	enum xp_retval (*partid_to_nasids) (short, void *);
270  };
271  
272  extern struct xpc_interface xpc_interface;
273  
274  extern void xpc_set_interface(void (*)(int),
275  			      void (*)(int),
276  			      enum xp_retval (*)(short, int, u32, void *, u16),
277  			      enum xp_retval (*)(short, int, u32, void *, u16,
278  						 xpc_notify_func, void *),
279  			      void (*)(short, int, void *),
280  			      enum xp_retval (*)(short, void *));
281  extern void xpc_clear_interface(void);
282  
283  extern enum xp_retval xpc_connect(int, xpc_channel_func, void *, u16,
284  				   u16, u32, u32);
285  extern void xpc_disconnect(int);
286  
287  static inline enum xp_retval
xpc_send(short partid,int ch_number,u32 flags,void * payload,u16 payload_size)288  xpc_send(short partid, int ch_number, u32 flags, void *payload,
289  	 u16 payload_size)
290  {
291  	if (!xpc_interface.send)
292  		return xpNotLoaded;
293  
294  	return xpc_interface.send(partid, ch_number, flags, payload,
295  				  payload_size);
296  }
297  
298  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)299  xpc_send_notify(short partid, int ch_number, u32 flags, void *payload,
300  		u16 payload_size, xpc_notify_func func, void *key)
301  {
302  	if (!xpc_interface.send_notify)
303  		return xpNotLoaded;
304  
305  	return xpc_interface.send_notify(partid, ch_number, flags, payload,
306  					 payload_size, func, key);
307  }
308  
309  static inline void
xpc_received(short partid,int ch_number,void * payload)310  xpc_received(short partid, int ch_number, void *payload)
311  {
312  	if (xpc_interface.received)
313  		xpc_interface.received(partid, ch_number, payload);
314  }
315  
316  static inline enum xp_retval
xpc_partid_to_nasids(short partid,void * nasids)317  xpc_partid_to_nasids(short partid, void *nasids)
318  {
319  	if (!xpc_interface.partid_to_nasids)
320  		return xpNotLoaded;
321  
322  	return xpc_interface.partid_to_nasids(partid, nasids);
323  }
324  
325  extern short xp_max_npartitions;
326  extern short xp_partition_id;
327  extern u8 xp_region_size;
328  
329  extern unsigned long (*xp_pa) (void *);
330  extern unsigned long (*xp_socket_pa) (unsigned long);
331  extern enum xp_retval (*xp_remote_memcpy) (unsigned long, const unsigned long,
332  		       size_t);
333  extern int (*xp_cpu_to_nasid) (int);
334  extern enum xp_retval (*xp_expand_memprotect) (unsigned long, unsigned long);
335  extern enum xp_retval (*xp_restrict_memprotect) (unsigned long, unsigned long);
336  
337  extern struct device *xp;
338  extern enum xp_retval xp_init_uv(void);
339  extern void xp_exit_uv(void);
340  
341  #endif /* _DRIVERS_MISC_SGIXP_XP_H */
342