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 enum xp_retval (*xp_remote_memcpy) (void *dst, const void *src, size_t len); 40 EXPORT_SYMBOL_GPL(xp_remote_memcpy); 41 42 /* 43 * xpc_registrations[] keeps track of xpc_connect()'s done by the kernel-level 44 * users of XPC. 45 */ 46 struct xpc_registration xpc_registrations[XPC_MAX_NCHANNELS]; 47 EXPORT_SYMBOL_GPL(xpc_registrations); 48 49 /* 50 * Initialize the XPC interface to indicate that XPC isn't loaded. 51 */ 52 static enum xp_retval 53 xpc_notloaded(void) 54 { 55 return xpNotLoaded; 56 } 57 58 struct xpc_interface xpc_interface = { 59 (void (*)(int))xpc_notloaded, 60 (void (*)(int))xpc_notloaded, 61 (enum xp_retval(*)(short, int, u32, void *, u16))xpc_notloaded, 62 (enum xp_retval(*)(short, int, u32, void *, u16, xpc_notify_func, 63 void *))xpc_notloaded, 64 (void (*)(short, int, void *))xpc_notloaded, 65 (enum xp_retval(*)(short, void *))xpc_notloaded 66 }; 67 EXPORT_SYMBOL_GPL(xpc_interface); 68 69 /* 70 * XPC calls this when it (the XPC module) has been loaded. 71 */ 72 void 73 xpc_set_interface(void (*connect) (int), 74 void (*disconnect) (int), 75 enum xp_retval (*send) (short, int, u32, void *, u16), 76 enum xp_retval (*send_notify) (short, int, u32, void *, u16, 77 xpc_notify_func, void *), 78 void (*received) (short, int, void *), 79 enum xp_retval (*partid_to_nasids) (short, void *)) 80 { 81 xpc_interface.connect = connect; 82 xpc_interface.disconnect = disconnect; 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.send = (enum xp_retval(*)(short, int, u32, void *, u16)) 99 xpc_notloaded; 100 xpc_interface.send_notify = (enum xp_retval(*)(short, int, u32, void *, 101 u16, xpc_notify_func, 102 void *))xpc_notloaded; 103 xpc_interface.received = (void (*)(short, int, void *)) 104 xpc_notloaded; 105 xpc_interface.partid_to_nasids = (enum xp_retval(*)(short, void *)) 106 xpc_notloaded; 107 } 108 EXPORT_SYMBOL_GPL(xpc_clear_interface); 109 110 /* 111 * Register for automatic establishment of a channel connection whenever 112 * a partition comes up. 113 * 114 * Arguments: 115 * 116 * ch_number - channel # to register for connection. 117 * func - function to call for asynchronous notification of channel 118 * state changes (i.e., connection, disconnection, error) and 119 * the arrival of incoming messages. 120 * key - pointer to optional user-defined value that gets passed back 121 * to the user on any callouts made to func. 122 * payload_size - size in bytes of the XPC message's payload area which 123 * contains a user-defined message. The user should make 124 * this large enough to hold their largest message. 125 * nentries - max #of XPC message entries a message queue can contain. 126 * The actual number, which is determined when a connection 127 * is established and may be less then requested, will be 128 * passed to the user via the xpConnected callout. 129 * assigned_limit - max number of kthreads allowed to be processing 130 * messages (per connection) at any given instant. 131 * idle_limit - max number of kthreads allowed to be idle at any given 132 * instant. 133 */ 134 enum xp_retval 135 xpc_connect(int ch_number, xpc_channel_func func, void *key, u16 payload_size, 136 u16 nentries, u32 assigned_limit, u32 idle_limit) 137 { 138 struct xpc_registration *registration; 139 140 DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); 141 DBUG_ON(payload_size == 0 || nentries == 0); 142 DBUG_ON(func == NULL); 143 DBUG_ON(assigned_limit == 0 || idle_limit > assigned_limit); 144 145 registration = &xpc_registrations[ch_number]; 146 147 if (mutex_lock_interruptible(®istration->mutex) != 0) 148 return xpInterrupted; 149 150 /* if XPC_CHANNEL_REGISTERED(ch_number) */ 151 if (registration->func != NULL) { 152 mutex_unlock(®istration->mutex); 153 return xpAlreadyRegistered; 154 } 155 156 /* register the channel for connection */ 157 registration->msg_size = XPC_MSG_SIZE(payload_size); 158 registration->nentries = nentries; 159 registration->assigned_limit = assigned_limit; 160 registration->idle_limit = idle_limit; 161 registration->key = key; 162 registration->func = func; 163 164 mutex_unlock(®istration->mutex); 165 166 xpc_interface.connect(ch_number); 167 168 return xpSuccess; 169 } 170 EXPORT_SYMBOL_GPL(xpc_connect); 171 172 /* 173 * Remove the registration for automatic connection of the specified channel 174 * when a partition comes up. 175 * 176 * Before returning this xpc_disconnect() will wait for all connections on the 177 * specified channel have been closed/torndown. So the caller can be assured 178 * that they will not be receiving any more callouts from XPC to their 179 * function registered via xpc_connect(). 180 * 181 * Arguments: 182 * 183 * ch_number - channel # to unregister. 184 */ 185 void 186 xpc_disconnect(int ch_number) 187 { 188 struct xpc_registration *registration; 189 190 DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); 191 192 registration = &xpc_registrations[ch_number]; 193 194 /* 195 * We've decided not to make this a down_interruptible(), since we 196 * figured XPC's users will just turn around and call xpc_disconnect() 197 * again anyways, so we might as well wait, if need be. 198 */ 199 mutex_lock(®istration->mutex); 200 201 /* if !XPC_CHANNEL_REGISTERED(ch_number) */ 202 if (registration->func == NULL) { 203 mutex_unlock(®istration->mutex); 204 return; 205 } 206 207 /* remove the connection registration for the specified channel */ 208 registration->func = NULL; 209 registration->key = NULL; 210 registration->nentries = 0; 211 registration->msg_size = 0; 212 registration->assigned_limit = 0; 213 registration->idle_limit = 0; 214 215 xpc_interface.disconnect(ch_number); 216 217 mutex_unlock(®istration->mutex); 218 219 return; 220 } 221 EXPORT_SYMBOL_GPL(xpc_disconnect); 222 223 int __init 224 xp_init(void) 225 { 226 enum xp_retval ret; 227 int ch_number; 228 229 if (is_shub()) 230 ret = xp_init_sn2(); 231 else if (is_uv()) 232 ret = xp_init_uv(); 233 else 234 ret = xpUnsupported; 235 236 if (ret != xpSuccess) 237 return -ENODEV; 238 239 /* initialize the connection registration mutex */ 240 for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++) 241 mutex_init(&xpc_registrations[ch_number].mutex); 242 243 return 0; 244 } 245 246 module_init(xp_init); 247 248 void __exit 249 xp_exit(void) 250 { 251 if (is_shub()) 252 xp_exit_sn2(); 253 else if (is_uv()) 254 xp_exit_uv(); 255 } 256 257 module_exit(xp_exit); 258 259 MODULE_AUTHOR("Silicon Graphics, Inc."); 260 MODULE_DESCRIPTION("Cross Partition (XP) base"); 261 MODULE_LICENSE("GPL"); 262