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 */
86enum 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 */
204typedef 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 */
229typedef 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 */
246struct 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
262struct 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
272extern struct xpc_interface xpc_interface;
273
274extern 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 *));
281extern void xpc_clear_interface(void);
282
283extern enum xp_retval xpc_connect(int, xpc_channel_func, void *, u16,
284 u16, u32, u32);
285extern void xpc_disconnect(int);
286
287static inline enum xp_retval
288xpc_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
298static inline enum xp_retval
299xpc_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
309static inline void
310xpc_received(short partid, int ch_number, void *payload)
311{
312 if (xpc_interface.received)
313 xpc_interface.received(partid, ch_number, payload);
314}
315
316static inline enum xp_retval
317xpc_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
325extern short xp_max_npartitions;
326extern short xp_partition_id;
327extern u8 xp_region_size;
328
329extern unsigned long (*xp_pa) (void *);
330extern unsigned long (*xp_socket_pa) (unsigned long);
331extern enum xp_retval (*xp_remote_memcpy) (unsigned long, const unsigned long,
332 size_t);
333extern int (*xp_cpu_to_nasid) (int);
334extern enum xp_retval (*xp_expand_memprotect) (unsigned long, unsigned long);
335extern enum xp_retval (*xp_restrict_memprotect) (unsigned long, unsigned long);
336
337extern struct device *xp;
338extern enum xp_retval xp_init_uv(void);
339extern void xp_exit_uv(void);
340
341#endif /* _DRIVERS_MISC_SGIXP_XP_H */
342

source code of linux/drivers/misc/sgi-xp/xp.h