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   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 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
  22 unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
  23 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
  24 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
  25
  26 /* I2O drivers lock and array */
  27 static spinlock_t i2o_drivers_lock;
  28 static struct i2o_driver **i2o_drivers;
  29
  30 /**
  31  *      i2o_bus_match - Tell if a I2O device class id match the class ids of
  32  *                      the I2O driver (OSM)
  33  *
  34  *      @dev: device which should be verified
  35  *      @drv: the driver to match against
  36  *
  37  *      Used by the bus to check if the driver wants to handle the device.
  38  *
  39  *      Returns 1 if the class ids of the driver match the class id of the
  40  *      device, otherwise 0.
  41  */
  42 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
  43 {
  44         struct i2o_device *i2o_dev = to_i2o_device(dev);
  45         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
  46         struct i2o_class_id *ids = i2o_drv->classes;
  47
  48         if (ids)
  49                 while (ids->class_id != I2O_CLASS_END) {
  50                         if (ids->class_id == i2o_dev->lct_data.class_id)
  51                                 return 1;
  52                         ids++;
  53                 }
  54         return 0;
  55 };
  56
  57 /* I2O bus type */
  58 struct bus_type i2o_bus_type = {
  59         .name = "i2o",
  60         .match = i2o_bus_match,
  61 };
  62
  63 /**
  64  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
  65  *      @drv: I2O driver which should be registered
  66  *
  67  *      Registers the OSM drv in the I2O core and creates an event queues if
  68  *      necessary.
  69  *
  70  *      Returns 0 on success or negative error code on failure.
  71  */
  72 int i2o_driver_register(struct i2o_driver *drv)
  73 {
  74         struct i2o_controller *c;
  75         int i;
  76         int rc = 0;
  77         unsigned long flags;
  78
  79         pr_debug("i2o: Register driver %s\n", drv->name);
  80
  81         if (drv->event) {
  82                 drv->event_queue = create_workqueue(drv->name);
  83                 if (!drv->event_queue) {
  84                         printk(KERN_ERR "i2o: Could not initialize event queue "
  85                                "for driver %s\n", drv->name);
  86                         return -EFAULT;
  87                 }
  88                 pr_debug("i2o: Event queue initialized for driver %s\n",
  89                          drv->name);
  90         } else
  91                 drv->event_queue = NULL;
  92
  93         drv->driver.name = drv->name;
  94         drv->driver.bus = &i2o_bus_type;
  95
  96         spin_lock_irqsave(&i2o_drivers_lock, flags);
  97
  98         for (i = 0; i2o_drivers[i]; i++)
  99                 if (i >= i2o_max_drivers) {
 100                         printk(KERN_ERR "i2o: too many drivers registered, "
 101                                "increase max_drivers\n");
 102                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 103                         return -EFAULT;
 104                 }
 105
 106         drv->context = i;
 107         i2o_drivers[i] = drv;
 108
 109         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 110
 111         pr_debug("i2o: driver %s gets context id %d\n", drv->name,
 112                  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         pr_debug("i2o: 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                 pr_debug("i2o: 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                         struct i2o_message __iomem *msg)
 181 {
 182         struct i2o_driver *drv;
 183         u32 context = readl(&msg->u.s.icntxt);
 184
 185         if (likely(context < i2o_max_drivers)) {
 186                 spin_lock(&i2o_drivers_lock);
 187                 drv = i2o_drivers[context];
 188                 spin_unlock(&i2o_drivers_lock);
 189
 190                 if (unlikely(!drv)) {
 191                         printk(KERN_WARNING "%s: Spurious reply to unknown "
 192                                "driver %d\n", c->name, context);
 193                         return -EIO;
 194                 }
 195
 196                 if ((readl(&msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 197                         struct i2o_device *dev, *tmp;
 198                         struct i2o_event *evt;
 199                         u16 size;
 200                         u16 tid;
 201
 202                         tid = readl(&msg->u.head[1]) & 0x1fff;
 203
 204                         pr_debug("%s: event received from device %d\n", c->name,
 205                                  tid);
 206
 207                         /* cut of header from message size (in 32-bit words) */
 208                         size = (readl(&msg->u.head[0]) >> 16) - 5;
 209
 210                         evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 211                         if (!evt)
 212                                 return -ENOMEM;
 213                         memset(evt, 0, size * 4 + sizeof(*evt));
 214
 215                         evt->size = size;
 216                         memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt,
 217                                       (size + 2) * 4);
 218
 219                         list_for_each_entry_safe(dev, tmp, &c->devices, list)
 220                             if (dev->lct_data.tid == tid) {
 221                                 evt->i2o_dev = dev;
 222                                 break;
 223                         }
 224
 225                         INIT_WORK(&evt->work, (void (*)(void *))drv->event,
 226                                   evt);
 227                         queue_work(drv->event_queue, &evt->work);
 228                         return 1;
 229                 }
 230
 231                 if (likely(drv->reply))
 232                         return drv->reply(c, m, msg);
 233                 else
 234                         pr_debug("%s: Reply to driver %s, but no reply function"
 235                                  " defined!\n", c->name, drv->name);
 236                 return -EIO;
 237         } else
 238                 printk(KERN_WARNING "%s: Spurious reply to unknown driver "
 239                        "%d\n", c->name, readl(&msg->u.s.icntxt));
 240         return -EIO;
 241 }
 242
 243 /**
 244  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 245  *                                             to all I2O drivers
 246  *
 247  *      Send notifications to all registered drivers that a new controller was
 248  *      added.
 249  */
 250 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 251 {
 252         int i;
 253         struct i2o_driver *drv;
 254
 255         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 256                 drv = i2o_drivers[i];
 257
 258                 if (drv)
 259                         i2o_driver_notify_controller_add(drv, c);
 260         }
 261 }
 262
 263 /**
 264  *      i2o_driver_notify_controller_remove_all - Send notify of removed
 265  *                                                controller to all I2O drivers
 266  *
 267  *      Send notifications to all registered drivers that a controller was
 268  *      removed.
 269  */
 270 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 271 {
 272         int i;
 273         struct i2o_driver *drv;
 274
 275         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 276                 drv = i2o_drivers[i];
 277
 278                 if (drv)
 279                         i2o_driver_notify_controller_remove(drv, c);
 280         }
 281 }
 282
 283 /**
 284  *      i2o_driver_notify_device_add_all - Send notify of added device to all
 285  *                                         I2O drivers
 286  *
 287  *      Send notifications to all registered drivers that a device was added.
 288  */
 289 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 290 {
 291         int i;
 292         struct i2o_driver *drv;
 293
 294         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 295                 drv = i2o_drivers[i];
 296
 297                 if (drv)
 298                         i2o_driver_notify_device_add(drv, i2o_dev);
 299         }
 300 }
 301
 302 /**
 303  *      i2o_driver_notify_device_remove_all - Send notify of removed device to
 304  *                                            all I2O drivers
 305  *
 306  *      Send notifications to all registered drivers that a device was removed.
 307  */
 308 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 309 {
 310         int i;
 311         struct i2o_driver *drv;
 312
 313         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 314                 drv = i2o_drivers[i];
 315
 316                 if (drv)
 317                         i2o_driver_notify_device_remove(drv, i2o_dev);
 318         }
 319 }
 320
 321 /**
 322  *      i2o_driver_init - initialize I2O drivers (OSMs)
 323  *
 324  *      Registers the I2O bus and allocate memory for the array of OSMs.
 325  *
 326  *      Returns 0 on success or negative error code on failure.
 327  */
 328 int __init i2o_driver_init(void)
 329 {
 330         int rc = 0;
 331
 332         spin_lock_init(&i2o_drivers_lock);
 333
 334         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
 335             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
 336              (2 * i2o_max_drivers - 1))) {
 337                 printk(KERN_WARNING "i2o: max_drivers set to %d, but must be "
 338                        ">=2 and <= 64 and a power of 2\n", i2o_max_drivers);
 339                 i2o_max_drivers = I2O_MAX_DRIVERS;
 340         }
 341         printk(KERN_INFO "i2o: max drivers = %d\n", i2o_max_drivers);
 342
 343         i2o_drivers =
 344             kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
 345         if (!i2o_drivers)
 346                 return -ENOMEM;
 347
 348         memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));
 349
 350         rc = bus_register(&i2o_bus_type);
 351
 352         if (rc < 0)
 353                 kfree(i2o_drivers);
 354
 355         return rc;
 356 };
 357
 358 /**
 359  *      i2o_driver_exit - clean up I2O drivers (OSMs)
 360  *
 361  *      Unregisters the I2O bus and free driver array.
 362  */
 363 void __exit i2o_driver_exit(void)
 364 {
 365         bus_unregister(&i2o_bus_type);
 366         kfree(i2o_drivers);
 367 };
 368
 369 EXPORT_SYMBOL(i2o_driver_register);
 370 EXPORT_SYMBOL(i2o_driver_unregister);
 371 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
 372 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
 373 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
 374 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);