xref: /openbmc/linux/drivers/misc/sgi-xp/xp_main.c (revision f3539c12)
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  * Cross Partition (XP) base.
11  *
12  *	XP provides a base from which its users can interact
13  *	with XPC, yet not be dependent on XPC.
14  *
15  */
16 
17 #include <linux/module.h>
18 #include <linux/device.h>
19 #include "xp.h"
20 
21 /* define the XP debug device structures to be used with dev_dbg() et al */
22 
23 struct device_driver xp_dbg_name = {
24 	.name = "xp"
25 };
26 
27 struct device xp_dbg_subname = {
28 	.init_name = "",		/* set to "" */
29 	.driver = &xp_dbg_name
30 };
31 
32 struct device *xp = &xp_dbg_subname;
33 
34 /* max #of partitions possible */
35 short xp_max_npartitions;
36 EXPORT_SYMBOL_GPL(xp_max_npartitions);
37 
38 short xp_partition_id;
39 EXPORT_SYMBOL_GPL(xp_partition_id);
40 
41 u8 xp_region_size;
42 EXPORT_SYMBOL_GPL(xp_region_size);
43 
44 unsigned long (*xp_pa) (void *addr);
45 EXPORT_SYMBOL_GPL(xp_pa);
46 
47 unsigned long (*xp_socket_pa) (unsigned long gpa);
48 EXPORT_SYMBOL_GPL(xp_socket_pa);
49 
50 enum xp_retval (*xp_remote_memcpy) (unsigned long dst_gpa,
51 				    const unsigned long src_gpa, size_t len);
52 EXPORT_SYMBOL_GPL(xp_remote_memcpy);
53 
54 int (*xp_cpu_to_nasid) (int cpuid);
55 EXPORT_SYMBOL_GPL(xp_cpu_to_nasid);
56 
57 enum xp_retval (*xp_expand_memprotect) (unsigned long phys_addr,
58 					unsigned long size);
59 EXPORT_SYMBOL_GPL(xp_expand_memprotect);
60 enum xp_retval (*xp_restrict_memprotect) (unsigned long phys_addr,
61 					  unsigned long size);
62 EXPORT_SYMBOL_GPL(xp_restrict_memprotect);
63 
64 /*
65  * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level
66  * users of XPC.
67  */
68 struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS];
69 EXPORT_SYMBOL_GPL(xpc_registrations);
70 
71 /*
72  * Initialize the XPC interface to indicate that XPC isn't loaded.
73  */
74 static enum xp_retval
75 xpc_notloaded(void)
76 {
77 	return xpNotLoaded;
78 }
79 
80 struct xpc_interface xpc_interface = {
81 	(void (*)(int))xpc_notloaded,
82 	(void (*)(int))xpc_notloaded,
83 	(enum xp_retval(*)(short, int, u32, void *, u16))xpc_notloaded,
84 	(enum xp_retval(*)(short, int, u32, void *, u16, xpc_notify_func,
85 			   void *))xpc_notloaded,
86 	(void (*)(short, int, void *))xpc_notloaded,
87 	(enum xp_retval(*)(short, void *))xpc_notloaded
88 };
89 EXPORT_SYMBOL_GPL(xpc_interface);
90 
91 /*
92  * XPC calls this when it (the XPC module) has been loaded.
93  */
94 void
95 xpc_set_interface(void (*connect) (int),
96 		  void (*disconnect) (int),
97 		  enum xp_retval (*send) (short, int, u32, void *, u16),
98 		  enum xp_retval (*send_notify) (short, int, u32, void *, u16,
99 						  xpc_notify_func, void *),
100 		  void (*received) (short, int, void *),
101 		  enum xp_retval (*partid_to_nasids) (short, void *))
102 {
103 	xpc_interface.connect = connect;
104 	xpc_interface.disconnect = disconnect;
105 	xpc_interface.send = send;
106 	xpc_interface.send_notify = send_notify;
107 	xpc_interface.received = received;
108 	xpc_interface.partid_to_nasids = partid_to_nasids;
109 }
110 EXPORT_SYMBOL_GPL(xpc_set_interface);
111 
112 /*
113  * XPC calls this when it (the XPC module) is being unloaded.
114  */
115 void
116 xpc_clear_interface(void)
117 {
118 	xpc_interface.connect = (void (*)(int))xpc_notloaded;
119 	xpc_interface.disconnect = (void (*)(int))xpc_notloaded;
120 	xpc_interface.send = (enum xp_retval(*)(short, int, u32, void *, u16))
121 	    xpc_notloaded;
122 	xpc_interface.send_notify = (enum xp_retval(*)(short, int, u32, void *,
123 						       u16, xpc_notify_func,
124 						       void *))xpc_notloaded;
125 	xpc_interface.received = (void (*)(short, int, void *))
126 	    xpc_notloaded;
127 	xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *))
128 	    xpc_notloaded;
129 }
130 EXPORT_SYMBOL_GPL(xpc_clear_interface);
131 
132 /*
133  * Register for automatic establishment of a channel connection whenever
134  * a partition comes up.
135  *
136  * Arguments:
137  *
138  *	ch_number - channel # to register for connection.
139  *	func - function to call for asynchronous notification of channel
140  *	       state changes (i.e., connection, disconnection, error) and
141  *	       the arrival of incoming messages.
142  *      key - pointer to optional user-defined value that gets passed back
143  *	      to the user on any callouts made to func.
144  *	payload_size - size in bytes of the XPC message's payload area which
145  *		       contains a user-defined message. The user should make
146  *		       this large enough to hold their largest message.
147  *	nentries - max #of XPC message entries a message queue can contain.
148  *		   The actual number, which is determined when a connection
149  * 		   is established and may be less then requested, will be
150  *		   passed to the user via the xpConnected callout.
151  *	assigned_limit - max number of kthreads allowed to be processing
152  * 			 messages (per connection) at any given instant.
153  *	idle_limit - max number of kthreads allowed to be idle at any given
154  * 		     instant.
155  */
156 enum xp_retval
157 xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
158 	    u16 nentries, u32 assigned_limit, u32 idle_limit)
159 {
160 	struct xpc_registration *registration;
161 
162 	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
163 	DBUG_ON(payload_size == 0 || nentries == 0);
164 	DBUG_ON(func == NULL);
165 	DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
166 
167 	if (XPC_MSG_SIZE(payload_size) > XPC_MSG_MAX_SIZE)
168 		return xpPayloadTooBig;
169 
170 	registration = &xpc_registrations[ch_number];
171 
172 	if (mutex_lock_interruptible(&registration->mutex) != 0)
173 		return xpInterrupted;
174 
175 	/* if XPC_CHANNEL_REGISTERED(ch_number) */
176 	if (registration->func != NULL) {
177 		mutex_unlock(&registration->mutex);
178 		return xpAlreadyRegistered;
179 	}
180 
181 	/* register the channel for connection */
182 	registration->entry_size = XPC_MSG_SIZE(payload_size);
183 	registration->nentries = nentries;
184 	registration->assigned_limit = assigned_limit;
185 	registration->idle_limit = idle_limit;
186 	registration->key = key;
187 	registration->func = func;
188 
189 	mutex_unlock(&registration->mutex);
190 
191 	xpc_interface.connect(ch_number);
192 
193 	return xpSuccess;
194 }
195 EXPORT_SYMBOL_GPL(xpc_connect);
196 
197 /*
198  * Remove the registration for automatic connection of the specified channel
199  * when a partition comes up.
200  *
201  * Before returning this xpc_disconnect() will wait for all connections on the
202  * specified channel have been closed/torndown. So the caller can be assured
203  * that they will not be receiving any more callouts from XPC to their
204  * function registered via xpc_connect().
205  *
206  * Arguments:
207  *
208  *	ch_number - channel # to unregister.
209  */
210 void
211 xpc_disconnect(int ch_number)
212 {
213 	struct xpc_registration *registration;
214 
215 	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
216 
217 	registration = &xpc_registrations[ch_number];
218 
219 	/*
220 	 * We've decided not to make this a down_interruptible(), since we
221 	 * figured XPC's users will just turn around and call xpc_disconnect()
222 	 * again anyways, so we might as well wait, if need be.
223 	 */
224 	mutex_lock(&registration->mutex);
225 
226 	/* if !XPC_CHANNEL_REGISTERED(ch_number) */
227 	if (registration->func == NULL) {
228 		mutex_unlock(&registration->mutex);
229 		return;
230 	}
231 
232 	/* remove the connection registration for the specified channel */
233 	registration->func = NULL;
234 	registration->key = NULL;
235 	registration->nentries = 0;
236 	registration->entry_size = 0;
237 	registration->assigned_limit = 0;
238 	registration->idle_limit = 0;
239 
240 	xpc_interface.disconnect(ch_number);
241 
242 	mutex_unlock(&registration->mutex);
243 
244 	return;
245 }
246 EXPORT_SYMBOL_GPL(xpc_disconnect);
247 
248 int __init
249 xp_init(void)
250 {
251 	enum xp_retval ret;
252 	int ch_number;
253 
254 	/* initialize the connection registration mutex */
255 	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++)
256 		mutex_init(&xpc_registrations[ch_number].mutex);
257 
258 	if (is_shub())
259 		ret = xp_init_sn2();
260 	else if (is_uv())
261 		ret = xp_init_uv();
262 	else
263 		ret = 0;
264 
265 	if (ret != xpSuccess)
266 		return ret;
267 
268 	return 0;
269 }
270 
271 module_init(xp_init);
272 
273 void __exit
274 xp_exit(void)
275 {
276 	if (is_shub())
277 		xp_exit_sn2();
278 	else if (is_uv())
279 		xp_exit_uv();
280 }
281 
282 module_exit(xp_exit);
283 
284 MODULE_AUTHOR("Silicon Graphics, Inc.");
285 MODULE_DESCRIPTION("Cross Partition (XP) base");
286 MODULE_LICENSE("GPL");
287