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 /* 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("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("Event queue initialized for driver %s\n", drv->name);
  89         } else
  90                 drv->event_queue = NULL;
  91
  92         drv->driver.name = drv->name;
  93         drv->driver.bus = &i2o_bus_type;
  94
  95         spin_lock_irqsave(&i2o_drivers_lock, flags);
  96
  97         for (i = 0; i2o_drivers[i]; i++)
  98                 if (i >= i2o_max_drivers) {
  99                         printk(KERN_ERR "i2o: too many drivers registered, "
 100                                "increase max_drivers\n");
 101                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 102                         return -EFAULT;
 103                 }
 104
 105         drv->context = i;
 106         i2o_drivers[i] = drv;
 107
 108         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 109
 110         pr_debug("driver %s gets context id %d\n", drv->name, drv->context);
 111
 112         list_for_each_entry(c, &i2o_controllers, list) {
 113                 struct i2o_device *i2o_dev;
 114
 115                 i2o_driver_notify_controller_add(drv, c);
 116                 list_for_each_entry(i2o_dev, &c->devices, list)
 117                         i2o_driver_notify_device_add(drv, i2o_dev);
 118         }
 119
 120
 121         rc = driver_register(&drv->driver);
 122         if (rc)
 123                 destroy_workqueue(drv->event_queue);
 124
 125         return rc;
 126 };
 127
 128 /**
 129  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 130  *      @drv: I2O driver which should be unregistered
 131  *
 132  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 133  *      necessary.
 134  */
 135 void i2o_driver_unregister(struct i2o_driver *drv)
 136 {
 137         struct i2o_controller *c;
 138         unsigned long flags;
 139
 140         pr_debug("unregister driver %s\n", drv->name);
 141
 142         driver_unregister(&drv->driver);
 143
 144         list_for_each_entry(c, &i2o_controllers, list) {
 145                 struct i2o_device *i2o_dev;
 146
 147                 list_for_each_entry(i2o_dev, &c->devices, list)
 148                     i2o_driver_notify_device_remove(drv, i2o_dev);
 149
 150                 i2o_driver_notify_controller_remove(drv, c);
 151         }
 152
 153         spin_lock_irqsave(&i2o_drivers_lock, flags);
 154         i2o_drivers[drv->context] = NULL;
 155         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 156
 157         if (drv->event_queue) {
 158                 destroy_workqueue(drv->event_queue);
 159                 drv->event_queue = NULL;
 160                 pr_debug("event queue removed for %s\n", drv->name);
 161         }
 162 };
 163
 164 /**
 165  *      i2o_driver_dispatch - dispatch an I2O reply message
 166  *      @c: I2O controller of the message
 167  *      @m: I2O message number
 168  *      @msg: I2O message to be delivered
 169  *
 170  *      The reply is delivered to the driver from which the original message
 171  *      was. This function is only called from interrupt context.
 172  *
 173  *      Returns 0 on success and the message should not be flushed. Returns > 0
 174  *      on success and if the message should be flushed afterwords. Returns
 175  *      negative error code on failure (the message will be flushed too).
 176  */
 177 int i2o_driver_dispatch(struct i2o_controller *c, u32 m,
 178                         struct i2o_message __iomem *msg)
 179 {
 180         struct i2o_driver *drv;
 181         u32 context = readl(&msg->u.s.icntxt);
 182
 183         if (likely(context < i2o_max_drivers)) {
 184                 spin_lock(&i2o_drivers_lock);
 185                 drv = i2o_drivers[context];
 186                 spin_unlock(&i2o_drivers_lock);
 187
 188                 if (unlikely(!drv)) {
 189                         printk(KERN_WARNING "i2o: Spurious reply to unknown "
 190                                "driver %d\n", context);
 191                         return -EIO;
 192                 }
 193
 194                 if ((readl(&msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 195                         struct i2o_device *dev, *tmp;
 196                         struct i2o_event *evt;
 197                         u16 size;
 198                         u16 tid;
 199
 200                         tid = readl(&msg->u.head[1]) & 0x1fff;
 201
 202                         pr_debug("%s: event received from device %d\n", c->name,
 203                                  tid);
 204
 205                         /* cut of header from message size (in 32-bit words) */
 206                         size = (readl(&msg->u.head[0]) >> 16) - 5;
 207
 208                         evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 209                         if (!evt)
 210                                 return -ENOMEM;
 211                         memset(evt, 0, size * 4 + sizeof(*evt));
 212
 213                         evt->size = size;
 214                         memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt,
 215                                       (size + 2) * 4);
 216
 217                         list_for_each_entry_safe(dev, tmp, &c->devices, list)
 218                             if (dev->lct_data.tid == tid) {
 219                                 evt->i2o_dev = dev;
 220                                 break;
 221                         }
 222
 223                         INIT_WORK(&evt->work, (void (*)(void *))drv->event,
 224                                   evt);
 225                         queue_work(drv->event_queue, &evt->work);
 226                         return 1;
 227                 }
 228
 229                 if (likely(drv->reply))
 230                         return drv->reply(c, m, msg);
 231                 else
 232                         pr_debug("%s: Reply to driver %s, but no reply function"
 233                                  " defined!\n", c->name, drv->name);
 234                 return -EIO;
 235         } else
 236                 printk(KERN_WARNING "i2o: Spurious reply to unknown driver "
 237                        "%d\n", readl(&msg->u.s.icntxt));
 238         return -EIO;
 239 }
 240
 241 /**
 242  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 243  *                                             to all I2O drivers
 244  *
 245  *      Send notifications to all registered drivers that a new controller was
 246  *      added.
 247  */
 248 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 249 {
 250         int i;
 251         struct i2o_driver *drv;
 252
 253         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 254                 drv = i2o_drivers[i];
 255
 256                 if (drv)
 257                         i2o_driver_notify_controller_add(drv, c);
 258         }
 259 }
 260
 261 /**
 262  *      i2o_driver_notify_controller_remove_all - Send notify of removed
 263  *                                                controller to all I2O drivers
 264  *
 265  *      Send notifications to all registered drivers that a controller was
 266  *      removed.
 267  */
 268 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 269 {
 270         int i;
 271         struct i2o_driver *drv;
 272
 273         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 274                 drv = i2o_drivers[i];
 275
 276                 if (drv)
 277                         i2o_driver_notify_controller_remove(drv, c);
 278         }
 279 }
 280
 281 /**
 282  *      i2o_driver_notify_device_add_all - Send notify of added device to all
 283  *                                         I2O drivers
 284  *
 285  *      Send notifications to all registered drivers that a device was added.
 286  */
 287 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 288 {
 289         int i;
 290         struct i2o_driver *drv;
 291
 292         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 293                 drv = i2o_drivers[i];
 294
 295                 if (drv)
 296                         i2o_driver_notify_device_add(drv, i2o_dev);
 297         }
 298 }
 299
 300 /**
 301  *      i2o_driver_notify_device_remove_all - Send notify of removed device to
 302  *                                            all I2O drivers
 303  *
 304  *      Send notifications to all registered drivers that a device was removed.
 305  */
 306 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 307 {
 308         int i;
 309         struct i2o_driver *drv;
 310
 311         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 312                 drv = i2o_drivers[i];
 313
 314                 if (drv)
 315                         i2o_driver_notify_device_remove(drv, i2o_dev);
 316         }
 317 }
 318
 319 /**
 320  *      i2o_driver_init - initialize I2O drivers (OSMs)
 321  *
 322  *      Registers the I2O bus and allocate memory for the array of OSMs.
 323  *
 324  *      Returns 0 on success or negative error code on failure.
 325  */
 326 int __init i2o_driver_init(void)
 327 {
 328         int rc = 0;
 329
 330         spin_lock_init(&i2o_drivers_lock);
 331
 332         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
 333             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
 334              (2 * i2o_max_drivers - 1))) {
 335                 printk(KERN_WARNING "i2o: max_drivers set to %d, but must be "
 336                        ">=2 and <= 64 and a power of 2\n", i2o_max_drivers);
 337                 i2o_max_drivers = I2O_MAX_DRIVERS;
 338         }
 339         printk(KERN_INFO "i2o: max_drivers=%d\n", i2o_max_drivers);
 340
 341         i2o_drivers =
 342             kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
 343         if (!i2o_drivers)
 344                 return -ENOMEM;
 345
 346         memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));
 347
 348         rc = bus_register(&i2o_bus_type);
 349
 350         if (rc < 0)
 351                 kfree(i2o_drivers);
 352
 353         return rc;
 354 };
 355
 356 /**
 357  *      i2o_driver_exit - clean up I2O drivers (OSMs)
 358  *
 359  *      Unregisters the I2O bus and free driver array.
 360  */
 361 void __exit i2o_driver_exit(void)
 362 {
 363         bus_unregister(&i2o_bus_type);
 364         kfree(i2o_drivers);
 365 };
 366
 367 EXPORT_SYMBOL(i2o_driver_register);
 368 EXPORT_SYMBOL(i2o_driver_unregister);
 369 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
 370 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
 371 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
 372 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);