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 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 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_shub())
 237                 ret = xp_init_sn2();
 238         else if (is_uv())
 239                 ret = xp_init_uv();
 240         else
 241                 ret = 0;
 242
 243         if (ret != xpSuccess)
 244                 return ret;
 245
 246         return 0;
 247 }
 248
 249 module_init(xp_init);
 250
 251 void __exit
 252 xp_exit(void)
 253 {
 254         if (is_shub())
 255                 xp_exit_sn2();
 256         else if (is_uv())
 257                 xp_exit_uv();
 258 }
 259
 260 module_exit(xp_exit);
 261
 262 MODULE_AUTHOR("Silicon Graphics, Inc.");
 263 MODULE_DESCRIPTION("Cross Partition (XP) base");
 264 MODULE_LICENSE("GPL");