drivers/message/i2o/driver.c

   1 /*
   2  *      Functions to handle I2O drivers (OSMs) and I2O bus type for sysfs
   3  *
   4  *      Copyright (C) 2004      Markus Lidel <Markus.Lidel@shadowconnect.com>
   5  *
   6  *      This program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation; either version 2 of the License, or (at your
   9  *      option) any later version.
  10  *
  11  *      Fixes/additions:
  12  *              Markus Lidel <Markus.Lidel@shadowconnect.com>
  13  *                      initial version.
  14  */
  15
  16 #include <linux/device.h>
  17 #include <linux/module.h>
  18 #include <linux/rwsem.h>
  19 #include <linux/i2o.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/string.h>
  22 #include <linux/slab.h>
  23 #include "core.h"
  24
  25 #define OSM_NAME        "i2o"
  26
  27 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
  28 static unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
  29 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
  30 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
  31
  32 /* I2O drivers lock and array */
  33 static spinlock_t i2o_drivers_lock;
  34 static struct i2o_driver **i2o_drivers;
  35
  36 /**
  37  *      i2o_bus_match - Tell if a I2O device class id match the class ids of
  38  *                      the I2O driver (OSM)
  39  *
  40  *      @dev: device which should be verified
  41  *      @drv: the driver to match against
  42  *
  43  *      Used by the bus to check if the driver wants to handle the device.
  44  *
  45  *      Returns 1 if the class ids of the driver match the class id of the
  46  *      device, otherwise 0.
  47  */
  48 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
  49 {
  50         struct i2o_device *i2o_dev = to_i2o_device(dev);
  51         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
  52         struct i2o_class_id *ids = i2o_drv->classes;
  53
  54         if (ids)
  55                 while (ids->class_id != I2O_CLASS_END) {
  56                         if (ids->class_id == i2o_dev->lct_data.class_id)
  57                                 return 1;
  58                         ids++;
  59                 }
  60         return 0;
  61 };
  62
  63 /* I2O bus type */
  64 struct bus_type i2o_bus_type = {
  65         .name = "i2o",
  66         .match = i2o_bus_match,
  67         .dev_attrs = i2o_device_attrs,
  68 };
  69
  70 /**
  71  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
  72  *      @drv: I2O driver which should be registered
  73  *
  74  *      Registers the OSM drv in the I2O core and creates an event queues if
  75  *      necessary.
  76  *
  77  *      Returns 0 on success or negative error code on failure.
  78  */
  79 int i2o_driver_register(struct i2o_driver *drv)
  80 {
  81         struct i2o_controller *c;
  82         int i;
  83         int rc = 0;
  84         unsigned long flags;
  85
  86         osm_debug("Register driver %s\n", drv->name);
  87
  88         if (drv->event) {
  89                 drv->event_queue = create_workqueue(drv->name);
  90                 if (!drv->event_queue) {
  91                         osm_err("Could not initialize event queue for driver "
  92                                 "%s\n", drv->name);
  93                         return -EFAULT;
  94                 }
  95                 osm_debug("Event queue initialized for driver %s\n", drv->name);
  96         } else
  97                 drv->event_queue = NULL;
  98
  99         drv->driver.name = drv->name;
 100         drv->driver.bus = &i2o_bus_type;
 101
 102         spin_lock_irqsave(&i2o_drivers_lock, flags);
 103
 104         for (i = 0; i2o_drivers[i]; i++)
 105                 if (i >= i2o_max_drivers) {
 106                         osm_err("too many drivers registered, increase "
 107                                 "max_drivers\n");
 108                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 109                         return -EFAULT;
 110                 }
 111
 112         drv->context = i;
 113         i2o_drivers[i] = drv;
 114
 115         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 116
 117         osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
 118
 119         list_for_each_entry(c, &i2o_controllers, list) {
 120                 struct i2o_device *i2o_dev;
 121
 122                 i2o_driver_notify_controller_add(drv, c);
 123                 list_for_each_entry(i2o_dev, &c->devices, list)
 124                     i2o_driver_notify_device_add(drv, i2o_dev);
 125         }
 126
 127         rc = driver_register(&drv->driver);
 128         if (rc)
 129                 destroy_workqueue(drv->event_queue);
 130
 131         return rc;
 132 };
 133
 134 /**
 135  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 136  *      @drv: I2O driver which should be unregistered
 137  *
 138  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 139  *      necessary.
 140  */
 141 void i2o_driver_unregister(struct i2o_driver *drv)
 142 {
 143         struct i2o_controller *c;
 144         unsigned long flags;
 145
 146         osm_debug("unregister driver %s\n", drv->name);
 147
 148         driver_unregister(&drv->driver);
 149
 150         list_for_each_entry(c, &i2o_controllers, list) {
 151                 struct i2o_device *i2o_dev;
 152
 153                 list_for_each_entry(i2o_dev, &c->devices, list)
 154                     i2o_driver_notify_device_remove(drv, i2o_dev);
 155
 156                 i2o_driver_notify_controller_remove(drv, c);
 157         }
 158
 159         spin_lock_irqsave(&i2o_drivers_lock, flags);
 160         i2o_drivers[drv->context] = NULL;
 161         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 162
 163         if (drv->event_queue) {
 164                 destroy_workqueue(drv->event_queue);
 165                 drv->event_queue = NULL;
 166                 osm_debug("event queue removed for %s\n", drv->name);
 167         }
 168 };
 169
 170 /**
 171  *      i2o_driver_dispatch - dispatch an I2O reply message
 172  *      @c: I2O controller of the message
 173  *      @m: I2O message number
 174  *      @msg: I2O message to be delivered
 175  *
 176  *      The reply is delivered to the driver from which the original message
 177  *      was. This function is only called from interrupt context.
 178  *
 179  *      Returns 0 on success and the message should not be flushed. Returns > 0
 180  *      on success and if the message should be flushed afterwords. Returns
 181  *      negative error code on failure (the message will be flushed too).
 182  */
 183 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
 184 {
 185         struct i2o_driver *drv;
 186         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
 187         u32 context = le32_to_cpu(msg->u.s.icntxt);
 188         unsigned long flags;
 189
 190         if (unlikely(context >= i2o_max_drivers)) {
 191                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 192                          context);
 193                 return -EIO;
 194         }
 195
 196         spin_lock_irqsave(&i2o_drivers_lock, flags);
 197         drv = i2o_drivers[context];
 198         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 199
 200         if (unlikely(!drv)) {
 201                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 202                          context);
 203                 return -EIO;
 204         }
 205
 206         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 207                 struct i2o_device *dev, *tmp;
 208                 struct i2o_event *evt;
 209                 u16 size;
 210                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
 211
 212                 osm_debug("event received from device %d\n", tid);
 213
 214                 if (!drv->event)
 215                         return -EIO;
 216
 217                 /* cut of header from message size (in 32-bit words) */
 218                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
 219
 220                 evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 221                 if (!evt)
 222                         return -ENOMEM;
 223                 memset(evt, 0, size * 4 + sizeof(*evt));
 224
 225                 evt->size = size;
 226                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
 227                 evt->event_indicator = le32_to_cpu(msg->body[0]);
 228                 memcpy(&evt->data, &msg->body[1], size * 4);
 229
 230                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
 231                     if (dev->lct_data.tid == tid) {
 232                         evt->i2o_dev = dev;
 233                         break;
 234                 }
 235
 236                 INIT_WORK(&evt->work, (void (*)(void *))drv->event, evt);
 237                 queue_work(drv->event_queue, &evt->work);
 238                 return 1;
 239         }
 240
 241         if (unlikely(!drv->reply)) {
 242                 osm_debug("%s: Reply to driver %s, but no reply function"
 243                           " defined!\n", c->name, drv->name);
 244                 return -EIO;
 245         }
 246
 247         return drv->reply(c, m, msg);
 248 }
 249
 250 /**
 251  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 252  *                                             to all I2O drivers
 253  *
 254  *      Send notifications to all registered drivers that a new controller was
 255  *      added.
 256  */
 257 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 258 {
 259         int i;
 260         struct i2o_driver *drv;
 261
 262         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 263                 drv = i2o_drivers[i];
 264
 265                 if (drv)
 266                         i2o_driver_notify_controller_add(drv, c);
 267         }
 268 }
 269
 270 /**
 271  *      i2o_driver_notify_controller_remove_all - Send notify of removed
 272  *                                                controller to all I2O drivers
 273  *
 274  *      Send notifications to all registered drivers that a controller was
 275  *      removed.
 276  */
 277 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 278 {
 279         int i;
 280         struct i2o_driver *drv;
 281
 282         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 283                 drv = i2o_drivers[i];
 284
 285                 if (drv)
 286                         i2o_driver_notify_controller_remove(drv, c);
 287         }
 288 }
 289
 290 /**
 291  *      i2o_driver_notify_device_add_all - Send notify of added device to all
 292  *                                         I2O drivers
 293  *
 294  *      Send notifications to all registered drivers that a device was added.
 295  */
 296 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 297 {
 298         int i;
 299         struct i2o_driver *drv;
 300
 301         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 302                 drv = i2o_drivers[i];
 303
 304                 if (drv)
 305                         i2o_driver_notify_device_add(drv, i2o_dev);
 306         }
 307 }
 308
 309 /**
 310  *      i2o_driver_notify_device_remove_all - Send notify of removed device to
 311  *                                            all I2O drivers
 312  *
 313  *      Send notifications to all registered drivers that a device was removed.
 314  */
 315 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 316 {
 317         int i;
 318         struct i2o_driver *drv;
 319
 320         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 321                 drv = i2o_drivers[i];
 322
 323                 if (drv)
 324                         i2o_driver_notify_device_remove(drv, i2o_dev);
 325         }
 326 }
 327
 328 /**
 329  *      i2o_driver_init - initialize I2O drivers (OSMs)
 330  *
 331  *      Registers the I2O bus and allocate memory for the array of OSMs.
 332  *
 333  *      Returns 0 on success or negative error code on failure.
 334  */
 335 int __init i2o_driver_init(void)
 336 {
 337         int rc = 0;
 338
 339         spin_lock_init(&i2o_drivers_lock);
 340
 341         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
 342             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
 343              (2 * i2o_max_drivers - 1))) {
 344                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
 345                          "a power of 2\n", i2o_max_drivers);
 346                 i2o_max_drivers = I2O_MAX_DRIVERS;
 347         }
 348         osm_info("max drivers = %d\n", i2o_max_drivers);
 349
 350         i2o_drivers =
 351             kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
 352         if (!i2o_drivers)
 353                 return -ENOMEM;
 354
 355         memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));
 356
 357         rc = bus_register(&i2o_bus_type);
 358
 359         if (rc < 0)
 360                 kfree(i2o_drivers);
 361
 362         return rc;
 363 };
 364
 365 /**
 366  *      i2o_driver_exit - clean up I2O drivers (OSMs)
 367  *
 368  *      Unregisters the I2O bus and free driver array.
 369  */
 370 void __exit i2o_driver_exit(void)
 371 {
 372         bus_unregister(&i2o_bus_type);
 373         kfree(i2o_drivers);
 374 };
 375
 376 EXPORT_SYMBOL(i2o_driver_register);
 377 EXPORT_SYMBOL(i2o_driver_unregister);
 378 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
 379 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
 380 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
 381 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);