err.no Git - linux-2.6/blob - 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
  21 #define OSM_NAME        "i2o"
  22
  23 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
  24 unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
  25 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
  26 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
  27
  28 /* I2O drivers lock and array */
  29 static spinlock_t i2o_drivers_lock;
  30 static struct i2o_driver **i2o_drivers;
  31
  32 /**
  33  *      i2o_bus_match - Tell if a I2O device class id match the class ids of
  34  *                      the I2O driver (OSM)
  35  *
  36  *      @dev: device which should be verified
  37  *      @drv: the driver to match against
  38  *
  39  *      Used by the bus to check if the driver wants to handle the device.
  40  *
  41  *      Returns 1 if the class ids of the driver match the class id of the
  42  *      device, otherwise 0.
  43  */
  44 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
  45 {
  46         struct i2o_device *i2o_dev = to_i2o_device(dev);
  47         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
  48         struct i2o_class_id *ids = i2o_drv->classes;
  49
  50         if (ids)
  51                 while (ids->class_id != I2O_CLASS_END) {
  52                         if (ids->class_id == i2o_dev->lct_data.class_id)
  53                                 return 1;
  54                         ids++;
  55                 }
  56         return 0;
  57 };
  58
  59 /* I2O bus type */
  60 struct bus_type i2o_bus_type = {
  61         .name = "i2o",
  62         .match = i2o_bus_match,
  63 };
  64
  65 /**
  66  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
  67  *      @drv: I2O driver which should be registered
  68  *
  69  *      Registers the OSM drv in the I2O core and creates an event queues if
  70  *      necessary.
  71  *
  72  *      Returns 0 on success or negative error code on failure.
  73  */
  74 int i2o_driver_register(struct i2o_driver *drv)
  75 {
  76         struct i2o_controller *c;
  77         int i;
  78         int rc = 0;
  79         unsigned long flags;
  80
  81         osm_debug("Register driver %s\n", drv->name);
  82
  83         if (drv->event) {
  84                 drv->event_queue = create_workqueue(drv->name);
  85                 if (!drv->event_queue) {
  86                         osm_err("Could not initialize event queue for driver "
  87                                 "%s\n", drv->name);
  88                         return -EFAULT;
  89                 }
  90                 osm_debug("Event queue initialized for driver %s\n", drv->name);
  91         } else
  92                 drv->event_queue = NULL;
  93
  94         drv->driver.name = drv->name;
  95         drv->driver.bus = &i2o_bus_type;
  96
  97         spin_lock_irqsave(&i2o_drivers_lock, flags);
  98
  99         for (i = 0; i2o_drivers[i]; i++)
 100                 if (i >= i2o_max_drivers) {
 101                         osm_err("too many drivers registered, increase "
 102                                 "max_drivers\n");
 103                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 104                         return -EFAULT;
 105                 }
 106
 107         drv->context = i;
 108         i2o_drivers[i] = drv;
 109
 110         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 111
 112         osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
 113
 114         list_for_each_entry(c, &i2o_controllers, list) {
 115                 struct i2o_device *i2o_dev;
 116
 117                 i2o_driver_notify_controller_add(drv, c);
 118                 list_for_each_entry(i2o_dev, &c->devices, list)
 119                         i2o_driver_notify_device_add(drv, i2o_dev);
 120         }
 121
 122
 123         rc = driver_register(&drv->driver);
 124         if (rc)
 125                 destroy_workqueue(drv->event_queue);
 126
 127         return rc;
 128 };
 129
 130 /**
 131  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 132  *      @drv: I2O driver which should be unregistered
 133  *
 134  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 135  *      necessary.
 136  */
 137 void i2o_driver_unregister(struct i2o_driver *drv)
 138 {
 139         struct i2o_controller *c;
 140         unsigned long flags;
 141
 142         osm_debug("unregister driver %s\n", drv->name);
 143
 144         driver_unregister(&drv->driver);
 145
 146         list_for_each_entry(c, &i2o_controllers, list) {
 147                 struct i2o_device *i2o_dev;
 148
 149                 list_for_each_entry(i2o_dev, &c->devices, list)
 150                     i2o_driver_notify_device_remove(drv, i2o_dev);
 151
 152                 i2o_driver_notify_controller_remove(drv, c);
 153         }
 154
 155         spin_lock_irqsave(&i2o_drivers_lock, flags);
 156         i2o_drivers[drv->context] = NULL;
 157         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 158
 159         if (drv->event_queue) {
 160                 destroy_workqueue(drv->event_queue);
 161                 drv->event_queue = NULL;
 162                 osm_debug("event queue removed for %s\n", drv->name);
 163         }
 164 };
 165
 166 /**
 167  *      i2o_driver_dispatch - dispatch an I2O reply message
 168  *      @c: I2O controller of the message
 169  *      @m: I2O message number
 170  *      @msg: I2O message to be delivered
 171  *
 172  *      The reply is delivered to the driver from which the original message
 173  *      was. This function is only called from interrupt context.
 174  *
 175  *      Returns 0 on success and the message should not be flushed. Returns > 0
 176  *      on success and if the message should be flushed afterwords. Returns
 177  *      negative error code on failure (the message will be flushed too).
 178  */
 179 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
 180 {
 181         struct i2o_driver *drv;
 182         struct i2o_message __iomem *msg = i2o_msg_out_to_virt(c, m);
 183         u32 context;
 184         unsigned long flags;
 185
 186         if(unlikely(!msg))
 187                 return -EIO;
 188
 189         context = readl(&msg->u.s.icntxt);
 190
 191         if (unlikely(context >= i2o_max_drivers)) {
 192                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 193                          context);
 194                 return -EIO;
 195         }
 196
 197         spin_lock_irqsave(&i2o_drivers_lock, flags);
 198         drv = i2o_drivers[context];
 199         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 200
 201         if (unlikely(!drv)) {
 202                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 203                          context);
 204                 return -EIO;
 205         }
 206
 207         if ((readl(&msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 208                 struct i2o_device *dev, *tmp;
 209                 struct i2o_event *evt;
 210                 u16 size;
 211                 u16 tid = readl(&msg->u.head[1]) & 0xfff;
 212
 213                 osm_debug("event received from device %d\n", tid);
 214
 215                 if (!drv->event)
 216                         return -EIO;
 217
 218                 /* cut of header from message size (in 32-bit words) */
 219                 size = (readl(&msg->u.head[0]) >> 16) - 5;
 220
 221                 evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC | __GFP_ZERO);
 222                 if (!evt)
 223                         return -ENOMEM;
 224
 225                 evt->size = size;
 226                 evt->tcntxt = readl(&msg->u.s.tcntxt);
 227                 evt->event_indicator = readl(&msg->body[0]);
 228                 memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt, 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);