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