drivers/misc/sgi-xp/xp_main.c

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