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/kernel.h> 18 #include <linux/module.h> 19 #include <linux/device.h> 20 #include "xp.h" 21 22 /* define the XP debug device structures to be used with dev_dbg() et al */ 23 24 struct device_driver xp_dbg_name = { 25 .name = "xp" 26 }; 27 28 struct device xp_dbg_subname = { 29 .bus_id = {0}, /* set to "" */ 30 .driver = &xp_dbg_name 31 }; 32 33 struct device *xp = &xp_dbg_subname; 34 35 /* max #of partitions possible */ 36 short xp_max_npartitions; 37 EXPORT_SYMBOL_GPL(xp_max_npartitions); 38 39 /* 40 * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level 41 * users of XPC. 42 */ 43 struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS]; 44 EXPORT_SYMBOL_GPL(xpc_registrations); 45 46 /* 47 * Initialize the XPC interface to indicate that XPC isn't loaded. 48 */ 49 static enum xp_retval 50 xpc_notloaded(void) 51 { 52 return xpNotLoaded; 53 } 54 55 struct xpc_interface xpc_interface = { 56 (void (*)(int))xpc_notloaded, 57 (void (*)(int))xpc_notloaded, 58 (enum xp_retval(*)(short, int, u32, void **))xpc_notloaded, 59 (enum xp_retval(*)(short, int, void *))xpc_notloaded, 60 (enum xp_retval(*)(short, int, void *, xpc_notify_func, void *)) 61 xpc_notloaded, 62 (void (*)(short, int, void *))xpc_notloaded, 63 (enum xp_retval(*)(short, void *))xpc_notloaded 64 }; 65 EXPORT_SYMBOL_GPL(xpc_interface); 66 67 /* 68 * XPC calls this when it (the XPC module) has been loaded. 69 */ 70 void 71 xpc_set_interface(void (*connect) (int), 72 void (*disconnect) (int), 73 enum xp_retval (*allocate) (short, int, u32, void **), 74 enum xp_retval (*send) (short, int, void *), 75 enum xp_retval (*send_notify) (short, int, void *, 76 xpc_notify_func, void *), 77 void (*received) (short, int, void *), 78 enum xp_retval (*partid_to_nasids) (short, void *)) 79 { 80 xpc_interface.connect = connect; 81 xpc_interface.disconnect = disconnect; 82 xpc_interface.allocate = allocate; 83 xpc_interface.send = send; 84 xpc_interface.send_notify = send_notify; 85 xpc_interface.received = received; 86 xpc_interface.partid_to_nasids = partid_to_nasids; 87 } 88 EXPORT_SYMBOL_GPL(xpc_set_interface); 89 90 /* 91 * XPC calls this when it (the XPC module) is being unloaded. 92 */ 93 void 94 xpc_clear_interface(void) 95 { 96 xpc_interface.connect = (void (*)(int))xpc_notloaded; 97 xpc_interface.disconnect = (void (*)(int))xpc_notloaded; 98 xpc_interface.allocate = (enum xp_retval(*)(short, int, u32, 99 void **))xpc_notloaded; 100 xpc_interface.send = (enum xp_retval(*)(short, int, void *)) 101 xpc_notloaded; 102 xpc_interface.send_notify = (enum xp_retval(*)(short, int, void *, 103 xpc_notify_func, 104 void *))xpc_notloaded; 105 xpc_interface.received = (void (*)(short, int, void *)) 106 xpc_notloaded; 107 xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *)) 108 xpc_notloaded; 109 } 110 EXPORT_SYMBOL_GPL(xpc_clear_interface); 111 112 /* 113 * Register for automatic establishment of a channel connection whenever 114 * a partition comes up. 115 * 116 * Arguments: 117 * 118 * ch_number - channel # to register for connection. 119 * func - function to call for asynchronous notification of channel 120 * state changes (i.e., connection, disconnection, error) and 121 * the arrival of incoming messages. 122 * key - pointer to optional user-defined value that gets passed back 123 * to the user on any callouts made to func. 124 * payload_size - size in bytes of the XPC message's payload area which 125 * contains a user-defined message. The user should make 126 * this large enough to hold their largest message. 127 * nentries - max #of XPC message entries a message queue can contain. 128 * The actual number, which is determined when a connection 129 * is established and may be less then requested, will be 130 * passed to the user via the xpConnected callout. 131 * assigned_limit - max number of kthreads allowed to be processing 132 * messages (per connection) at any given instant. 133 * idle_limit - max number of kthreads allowed to be idle at any given 134 * instant. 135 */ 136 enum xp_retval 137 xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size, 138 u16 nentries, u32 assigned_limit, u32 idle_limit) 139 { 140 struct xpc_registration *registration; 141 142 DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); 143 DBUG_ON(payload_size == 0 || nentries == 0); 144 DBUG_ON(func == NULL); 145 DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit); 146 147 registration = &xpc_registrations[ch_number]; 148 149 if (mutex_lock_interruptible(®istration->mutex) != 0) 150 return xpInterrupted; 151 152 /* if XPC_CHANNEL_REGISTERED(ch_number) */ 153 if (registration->func != NULL) { 154 mutex_unlock(®istration->mutex); 155 return xpAlreadyRegistered; 156 } 157 158 /* register the channel for connection */ 159 registration->msg_size = XPC_MSG_SIZE(payload_size); 160 registration->nentries = nentries; 161 registration->assigned_limit = assigned_limit; 162 registration->idle_limit = idle_limit; 163 registration->key = key; 164 registration->func = func; 165 166 mutex_unlock(®istration->mutex); 167 168 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(®istration->mutex); 202 203 /* if !XPC_CHANNEL_REGISTERED(ch_number) */ 204 if (registration->func == NULL) { 205 mutex_unlock(®istration->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->msg_size = 0; 214 registration->assigned_limit = 0; 215 registration->idle_limit = 0; 216 217 xpc_interface.disconnect(ch_number); 218 219 mutex_unlock(®istration->mutex); 220 221 return; 222 } 223 EXPORT_SYMBOL_GPL(xpc_disconnect); 224 225 int __init 226 xp_init(void) 227 { 228 enum xp_retval ret; 229 int ch_number; 230 231 if (is_shub()) 232 ret = xp_init_sn2(); 233 else if (is_uv()) 234 ret = xp_init_uv(); 235 else 236 ret = xpUnsupported; 237 238 if (ret != xpSuccess) 239 return -ENODEV; 240 241 /* initialize the connection registration mutex */ 242 for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++) 243 mutex_init(&xpc_registrations[ch_number].mutex); 244 245 return 0; 246 } 247 248 module_init(xp_init); 249 250 void __exit 251 xp_exit(void) 252 { 253 if (is_shub()) 254 xp_exit_sn2(); 255 else if (is_uv()) 256 xp_exit_uv(); 257 } 258 259 module_exit(xp_exit); 260 261 MODULE_AUTHOR("Silicon Graphics, Inc."); 262 MODULE_DESCRIPTION("Cross Partition (XP) base"); 263 MODULE_LICENSE("GPL"); 264