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/drivers/misc/sgi-xp/xp_main.c

http://github.com/mirrors/linux
C | 260 lines | 138 code | 46 blank | 76 comment | 22 complexity | 9cf62df5d8f146f787875e54d8bbfc5c MD5 | raw file
  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
 23struct device_driver xp_dbg_name = {
 24	.name = "xp"
 25};
 26
 27struct device xp_dbg_subname = {
 28	.init_name = "",		/* set to "" */
 29	.driver = &xp_dbg_name
 30};
 31
 32struct device *xp = &xp_dbg_subname;
 33
 34/* max #of partitions possible */
 35short xp_max_npartitions;
 36EXPORT_SYMBOL_GPL(xp_max_npartitions);
 37
 38short xp_partition_id;
 39EXPORT_SYMBOL_GPL(xp_partition_id);
 40
 41u8 xp_region_size;
 42EXPORT_SYMBOL_GPL(xp_region_size);
 43
 44unsigned long (*xp_pa) (void *addr);
 45EXPORT_SYMBOL_GPL(xp_pa);
 46
 47unsigned long (*xp_socket_pa) (unsigned long gpa);
 48EXPORT_SYMBOL_GPL(xp_socket_pa);
 49
 50enum xp_retval (*xp_remote_memcpy) (unsigned long dst_gpa,
 51				    const unsigned long src_gpa, size_t len);
 52EXPORT_SYMBOL_GPL(xp_remote_memcpy);
 53
 54int (*xp_cpu_to_nasid) (int cpuid);
 55EXPORT_SYMBOL_GPL(xp_cpu_to_nasid);
 56
 57enum xp_retval (*xp_expand_memprotect) (unsigned long phys_addr,
 58					unsigned long size);
 59EXPORT_SYMBOL_GPL(xp_expand_memprotect);
 60enum xp_retval (*xp_restrict_memprotect) (unsigned long phys_addr,
 61					  unsigned long size);
 62EXPORT_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 */
 68struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS];
 69EXPORT_SYMBOL_GPL(xpc_registrations);
 70
 71/*
 72 * Initialize the XPC interface to NULL to indicate that XPC isn't loaded.
 73 */
 74struct xpc_interface xpc_interface = { };
 75EXPORT_SYMBOL_GPL(xpc_interface);
 76
 77/*
 78 * XPC calls this when it (the XPC module) has been loaded.
 79 */
 80void
 81xpc_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}
 96EXPORT_SYMBOL_GPL(xpc_set_interface);
 97
 98/*
 99 * XPC calls this when it (the XPC module) is being unloaded.
100 */
101void
102xpc_clear_interface(void)
103{
104	memset(&xpc_interface, 0, sizeof(xpc_interface));
105}
106EXPORT_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 */
132enum xp_retval
133xpc_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}
172EXPORT_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 */
187void
188xpc_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}
224EXPORT_SYMBOL_GPL(xpc_disconnect);
225
226int __init
227xp_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
247module_init(xp_init);
248
249void __exit
250xp_exit(void)
251{
252	if (is_uv())
253		xp_exit_uv();
254}
255
256module_exit(xp_exit);
257
258MODULE_AUTHOR("Silicon Graphics, Inc.");
259MODULE_DESCRIPTION("Cross Partition (XP) base");
260MODULE_LICENSE("GPL");