xref: /openbmc/linux/drivers/misc/sgi-xp/xp_main.c (revision a5b2c10c)
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 NULL to indicate that XPC isn't loaded.
73  */
74 struct xpc_interface xpc_interface = { };
75 EXPORT_SYMBOL_GPL(xpc_interface);
76 
77 /*
78  * XPC calls this when it (the XPC module) has been loaded.
79  */
80 void
81 xpc_set_interface(void (*connect) (int),
82 		  void (*disconnect) (int),
83 		  enum xp_retval (*send) (short, int, u32, void *, u16),
84 		  enum xp_retval (*send_notify) (short, int, u32, void *, u16,
85 						  xpc_notify_func, void *),
86 		  void (*received) (short, int, void *),
87 		  enum xp_retval (*partid_to_nasids) (short, void *))
88 {
89 	xpc_interface.connect = connect;
90 	xpc_interface.disconnect = disconnect;
91 	xpc_interface.send = send;
92 	xpc_interface.send_notify = send_notify;
93 	xpc_interface.received = received;
94 	xpc_interface.partid_to_nasids = partid_to_nasids;
95 }
96 EXPORT_SYMBOL_GPL(xpc_set_interface);
97 
98 /*
99  * XPC calls this when it (the XPC module) is being unloaded.
100  */
101 void
102 xpc_clear_interface(void)
103 {
104 	memset(&xpc_interface, 0, sizeof(xpc_interface));
105 }
106 EXPORT_SYMBOL_GPL(xpc_clear_interface);
107 
108 /*
109  * Register for automatic establishment of a channel connection whenever
110  * a partition comes up.
111  *
112  * Arguments:
113  *
114  *	ch_number - channel # to register for connection.
115  *	func - function to call for asynchronous notification of channel
116  *	       state changes (i.e., connection, disconnection, error) and
117  *	       the arrival of incoming messages.
118  *      key - pointer to optional user-defined value that gets passed back
119  *	      to the user on any callouts made to func.
120  *	payload_size - size in bytes of the XPC message's payload area which
121  *		       contains a user-defined message. The user should make
122  *		       this large enough to hold their largest message.
123  *	nentries - max #of XPC message entries a message queue can contain.
124  *		   The actual number, which is determined when a connection
125  * 		   is established and may be less then requested, will be
126  *		   passed to the user via the xpConnected callout.
127  *	assigned_limit - max number of kthreads allowed to be processing
128  * 			 messages (per connection) at any given instant.
129  *	idle_limit - max number of kthreads allowed to be idle at any given
130  * 		     instant.
131  */
132 enum xp_retval
133 xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size,
134 	    u16 nentries, u32 assigned_limit, u32 idle_limit)
135 {
136 	struct xpc_registration *registration;
137 
138 	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
139 	DBUG_ON(payload_size == 0 || nentries == 0);
140 	DBUG_ON(func == NULL);
141 	DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit);
142 
143 	if (XPC_MSG_SIZE(payload_size) > XPC_MSG_MAX_SIZE)
144 		return xpPayloadTooBig;
145 
146 	registration = &xpc_registrations[ch_number];
147 
148 	if (mutex_lock_interruptible(&registration->mutex) != 0)
149 		return xpInterrupted;
150 
151 	/* if XPC_CHANNEL_REGISTERED(ch_number) */
152 	if (registration->func != NULL) {
153 		mutex_unlock(&registration->mutex);
154 		return xpAlreadyRegistered;
155 	}
156 
157 	/* register the channel for connection */
158 	registration->entry_size = XPC_MSG_SIZE(payload_size);
159 	registration->nentries = nentries;
160 	registration->assigned_limit = assigned_limit;
161 	registration->idle_limit = idle_limit;
162 	registration->key = key;
163 	registration->func = func;
164 
165 	mutex_unlock(&registration->mutex);
166 
167 	if (xpc_interface.connect)
168 		xpc_interface.connect(ch_number);
169 
170 	return xpSuccess;
171 }
172 EXPORT_SYMBOL_GPL(xpc_connect);
173 
174 /*
175  * Remove the registration for automatic connection of the specified channel
176  * when a partition comes up.
177  *
178  * Before returning this xpc_disconnect() will wait for all connections on the
179  * specified channel have been closed/torndown. So the caller can be assured
180  * that they will not be receiving any more callouts from XPC to their
181  * function registered via xpc_connect().
182  *
183  * Arguments:
184  *
185  *	ch_number - channel # to unregister.
186  */
187 void
188 xpc_disconnect(int ch_number)
189 {
190 	struct xpc_registration *registration;
191 
192 	DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS);
193 
194 	registration = &xpc_registrations[ch_number];
195 
196 	/*
197 	 * We've decided not to make this a down_interruptible(), since we
198 	 * figured XPC's users will just turn around and call xpc_disconnect()
199 	 * again anyways, so we might as well wait, if need be.
200 	 */
201 	mutex_lock(&registration->mutex);
202 
203 	/* if !XPC_CHANNEL_REGISTERED(ch_number) */
204 	if (registration->func == NULL) {
205 		mutex_unlock(&registration->mutex);
206 		return;
207 	}
208 
209 	/* remove the connection registration for the specified channel */
210 	registration->func = NULL;
211 	registration->key = NULL;
212 	registration->nentries = 0;
213 	registration->entry_size = 0;
214 	registration->assigned_limit = 0;
215 	registration->idle_limit = 0;
216 
217 	if (xpc_interface.disconnect)
218 		xpc_interface.disconnect(ch_number);
219 
220 	mutex_unlock(&registration->mutex);
221 
222 	return;
223 }
224 EXPORT_SYMBOL_GPL(xpc_disconnect);
225 
226 static int __init
227 xp_init(void)
228 {
229 	enum xp_retval ret;
230 	int ch_number;
231 
232 	/* initialize the connection registration mutex */
233 	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++)
234 		mutex_init(&xpc_registrations[ch_number].mutex);
235 
236 	if (is_uv())
237 		ret = xp_init_uv();
238 	else
239 		ret = 0;
240 
241 	if (ret != xpSuccess)
242 		return ret;
243 
244 	return 0;
245 }
246 
247 module_init(xp_init);
248 
249 static void __exit
250 xp_exit(void)
251 {
252 	if (is_uv())
253 		xp_exit_uv();
254 }
255 
256 module_exit(xp_exit);
257 
258 MODULE_AUTHOR("Silicon Graphics, Inc.");
259 MODULE_DESCRIPTION("Cross Partition (XP) base");
260 MODULE_LICENSE("GPL");
261