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