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
  22 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
  23 unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
  24 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
  25 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
  26
  27 /* I2O drivers lock and array */
  28 static spinlock_t i2o_drivers_lock = SPIN_LOCK_UNLOCKED;
  29 static struct i2o_driver **i2o_drivers;
  30
  31 /**
  32  *      i2o_bus_match - Tell if a I2O device class id match the class ids of
  33  *                      the I2O driver (OSM)
  34  *
  35  *      @dev: device which should be verified
  36  *      @drv: the driver to match against
  37  *
  38  *      Used by the bus to check if the driver wants to handle the device.
  39  *
  40  *      Returns 1 if the class ids of the driver match the class id of the
  41  *      device, otherwise 0.
  42  */
  43 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
  44 {
  45         struct i2o_device *i2o_dev = to_i2o_device(dev);
  46         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
  47         struct i2o_class_id *ids = i2o_drv->classes;
  48
  49         if (ids)
  50                 while (ids->class_id != I2O_CLASS_END) {
  51                         if (ids->class_id == i2o_dev->lct_data.class_id)
  52                                 return 1;
  53                         ids++;
  54                 }
  55         return 0;
  56 };
  57
  58 /* I2O bus type */
  59 struct bus_type i2o_bus_type = {
  60         .name = "i2o",
  61         .match = i2o_bus_match,
  62 };
  63
  64 /**
  65  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
  66  *      @drv: I2O driver which should be registered
  67  *
  68  *      Registers the OSM drv in the I2O core and creates an event queues if
  69  *      necessary.
  70  *
  71  *      Returns 0 on success or negative error code on failure.
  72  */
  73 int i2o_driver_register(struct i2o_driver *drv)
  74 {
  75         struct i2o_controller *c;
  76         int i;
  77         int rc = 0;
  78         unsigned long flags;
  79
  80         pr_debug("Register driver %s\n", drv->name);
  81
  82         if (drv->event) {
  83                 drv->event_queue = create_workqueue(drv->name);
  84                 if (!drv->event_queue) {
  85                         printk(KERN_ERR "i2o: Could not initialize event queue "
  86                                "for driver %s\n", drv->name);
  87                         return -EFAULT;
  88                 }
  89                 pr_debug("Event queue initialized for driver %s\n", 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("driver %s gets context id %d\n", drv->name, drv->context);
 112
 113         list_for_each_entry(c, &i2o_controllers, list) {
 114                 struct i2o_device *i2o_dev;
 115
 116                 i2o_driver_notify_controller_add(drv, c);
 117                 list_for_each_entry(i2o_dev, &c->devices, list)
 118                         i2o_driver_notify_device_add(drv, i2o_dev);
 119         }
 120
 121
 122         rc = driver_register(&drv->driver);
 123         if (rc)
 124                 destroy_workqueue(drv->event_queue);
 125
 126         return rc;
 127 };
 128
 129 /**
 130  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 131  *      @drv: I2O driver which should be unregistered
 132  *
 133  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 134  *      necessary.
 135  */
 136 void i2o_driver_unregister(struct i2o_driver *drv)
 137 {
 138         struct i2o_controller *c;
 139         unsigned long flags;
 140
 141         pr_debug("unregister driver %s\n", drv->name);
 142
 143         driver_unregister(&drv->driver);
 144
 145         list_for_each_entry(c, &i2o_controllers, list) {
 146                 struct i2o_device *i2o_dev;
 147
 148                 list_for_each_entry(i2o_dev, &c->devices, list)
 149                         i2o_driver_notify_device_remove(drv, i2o_dev);
 150
 151                 i2o_driver_notify_controller_remove(drv, c);
 152         }
 153
 154         spin_lock_irqsave(&i2o_drivers_lock, flags);
 155         i2o_drivers[drv->context] = NULL;
 156         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 157
 158         if (drv->event_queue) {
 159                 destroy_workqueue(drv->event_queue);
 160                 drv->event_queue = NULL;
 161                 pr_debug("event queue removed for %s\n", drv->name);
 162         }
 163 };
 164
 165 /**
 166  *      i2o_driver_dispatch - dispatch an I2O reply message
 167  *      @c: I2O controller of the message
 168  *      @m: I2O message number
 169  *      @msg: I2O message to be delivered
 170  *
 171  *      The reply is delivered to the driver from which the original message
 172  *      was. This function is only called from interrupt context.
 173  *
 174  *      Returns 0 on success and the message should not be flushed. Returns > 0
 175  *      on success and if the message should be flushed afterwords. Returns
 176  *      negative error code on failure (the message will be flushed too).
 177  */
 178 int i2o_driver_dispatch(struct i2o_controller *c, u32 m,
 179                         struct i2o_message *msg)
 180 {
 181         struct i2o_driver *drv;
 182         u32 context = readl(&msg->u.s.icntxt);
 183
 184         if (likely(context < i2o_max_drivers)) {
 185                 spin_lock(&i2o_drivers_lock);
 186                 drv = i2o_drivers[context];
 187                 spin_unlock(&i2o_drivers_lock);
 188
 189                 if (unlikely(!drv)) {
 190                         printk(KERN_WARNING "i2o: Spurious reply to unknown "
 191                                "driver %d\n", context);
 192                         return -EIO;
 193                 }
 194
 195                 if ((readl(&msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 196                         struct i2o_device *dev, *tmp;
 197                         struct i2o_event *evt;
 198                         u16 size;
 199                         u16 tid;
 200
 201                         tid = readl(&msg->u.head[1]) & 0x1fff;
 202
 203                         pr_debug("%s: event received from device %d\n", c->name,
 204                                  tid);
 205
 206                         /* cut of header from message size (in 32-bit words) */
 207                         size = (readl(&msg->u.head[0]) >> 16) - 5;
 208
 209                         evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 210                         if (!evt)
 211                                 return -ENOMEM;
 212                         memset(evt, 0, size * 4 + sizeof(*evt));
 213
 214                         evt->size = size;
 215                         memcpy_fromio(&evt->tcntxt, &msg->u.s.tcntxt,
 216                                       (size + 2) * 4);
 217
 218                         list_for_each_entry_safe(dev, tmp, &c->devices, list)
 219                             if (dev->lct_data.tid == tid) {
 220                                 evt->i2o_dev = dev;
 221                                 break;
 222                         }
 223
 224                         INIT_WORK(&evt->work, (void (*)(void *))drv->event,
 225                                   evt);
 226                         queue_work(drv->event_queue, &evt->work);
 227                         return 1;
 228                 }
 229
 230                 if (likely(drv->reply))
 231                         return drv->reply(c, m, msg);
 232                 else
 233                         pr_debug("%s: Reply to driver %s, but no reply function"
 234                                  " defined!\n", c->name, drv->name);
 235                 return -EIO;
 236         } else
 237                 printk(KERN_WARNING "i2o: Spurious reply to unknown driver "
 238                        "%d\n", readl(&msg->u.s.icntxt));
 239         return -EIO;
 240 }
 241
 242 /**
 243  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 244  *                                             to all I2O drivers
 245  *
 246  *      Send notifications to all registered drivers that a new controller was
 247  *      added.
 248  */
 249 void i2o_driver_notify_controller_add_all(struct i2o_controller *c) {
 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         int i;
 270         struct i2o_driver *drv;
 271
 272         for(i = 0; i < I2O_MAX_DRIVERS; i ++) {
 273                 drv = i2o_drivers[i];
 274
 275                 if(drv)
 276                         i2o_driver_notify_controller_remove(drv, c);
 277         }
 278 }
 279
 280 /**
 281  *      i2o_driver_notify_device_add_all - Send notify of added device to all
 282  *                                         I2O drivers
 283  *
 284  *      Send notifications to all registered drivers that a device was added.
 285  */
 286 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev) {
 287         int i;
 288         struct i2o_driver *drv;
 289
 290         for(i = 0; i < I2O_MAX_DRIVERS; i ++) {
 291                 drv = i2o_drivers[i];
 292
 293                 if(drv)
 294                         i2o_driver_notify_device_add(drv, i2o_dev);
 295         }
 296 }
 297
 298 /**
 299  *      i2o_driver_notify_device_remove_all - Send notify of removed device to
 300  *                                            all I2O drivers
 301  *
 302  *      Send notifications to all registered drivers that a device was removed.
 303  */
 304 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev) {
 305         int i;
 306         struct i2o_driver *drv;
 307
 308         for(i = 0; i < I2O_MAX_DRIVERS; i ++) {
 309                 drv = i2o_drivers[i];
 310
 311                 if(drv)
 312                         i2o_driver_notify_device_remove(drv, i2o_dev);
 313         }
 314 }
 315
 316 /**
 317  *      i2o_driver_init - initialize I2O drivers (OSMs)
 318  *
 319  *      Registers the I2O bus and allocate memory for the array of OSMs.
 320  *
 321  *      Returns 0 on success or negative error code on failure.
 322  */
 323 int __init i2o_driver_init(void)
 324 {
 325         int rc = 0;
 326
 327         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
 328             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
 329              (2 * i2o_max_drivers - 1))) {
 330                 printk(KERN_WARNING "i2o: max_drivers set to %d, but must be "
 331                        ">=2 and <= 64 and a power of 2\n", i2o_max_drivers);
 332                 i2o_max_drivers = I2O_MAX_DRIVERS;
 333         }
 334         printk(KERN_INFO "i2o: max_drivers=%d\n", i2o_max_drivers);
 335
 336         i2o_drivers =
 337             kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
 338         if (!i2o_drivers)
 339                 return -ENOMEM;
 340
 341         memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));
 342
 343         rc = bus_register(&i2o_bus_type);
 344
 345         if (rc < 0)
 346                 kfree(i2o_drivers);
 347
 348         return rc;
 349 };
 350
 351 /**
 352  *      i2o_driver_exit - clean up I2O drivers (OSMs)
 353  *
 354  *      Unregisters the I2O bus and free driver array.
 355  */
 356 void __exit i2o_driver_exit(void)
 357 {
 358         bus_unregister(&i2o_bus_type);
 359         kfree(i2o_drivers);
 360 };
 361
 362 EXPORT_SYMBOL(i2o_driver_register);
 363 EXPORT_SYMBOL(i2o_driver_unregister);
 364 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
 365 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
 366 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
 367 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);