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