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                 if (drv->event) {
 128                         destroy_workqueue(drv->event_queue);
 129                         drv->event_queue = NULL;
 130                 }
 131         }
 132
 133         return rc;
 134 };
 135
 136 /**
 137  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 138  *      @drv: I2O driver which should be unregistered
 139  *
 140  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 141  *      necessary.
 142  */
 143 void i2o_driver_unregister(struct i2o_driver *drv)
 144 {
 145         struct i2o_controller *c;
 146         unsigned long flags;
 147
 148         osm_debug("unregister driver %s\n", drv->name);
 149
 150         driver_unregister(&drv->driver);
 151
 152         list_for_each_entry(c, &i2o_controllers, list) {
 153                 struct i2o_device *i2o_dev;
 154
 155                 list_for_each_entry(i2o_dev, &c->devices, list)
 156                     i2o_driver_notify_device_remove(drv, i2o_dev);
 157
 158                 i2o_driver_notify_controller_remove(drv, c);
 159         }
 160
 161         spin_lock_irqsave(&i2o_drivers_lock, flags);
 162         i2o_drivers[drv->context] = NULL;
 163         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 164
 165         if (drv->event_queue) {
 166                 destroy_workqueue(drv->event_queue);
 167                 drv->event_queue = NULL;
 168                 osm_debug("event queue removed for %s\n", drv->name);
 169         }
 170 };
 171
 172 /**
 173  *      i2o_driver_dispatch - dispatch an I2O reply message
 174  *      @c: I2O controller of the message
 175  *      @m: I2O message number
 176  *
 177  *      The reply is delivered to the driver from which the original message
 178  *      was. This function is only called from interrupt context.
 179  *
 180  *      Returns 0 on success and the message should not be flushed. Returns > 0
 181  *      on success and if the message should be flushed afterwords. Returns
 182  *      negative error code on failure (the message will be flushed too).
 183  */
 184 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
 185 {
 186         struct i2o_driver *drv;
 187         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
 188         u32 context = le32_to_cpu(msg->u.s.icntxt);
 189         unsigned long flags;
 190
 191         if (unlikely(context >= i2o_max_drivers)) {
 192                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 193                          context);
 194                 return -EIO;
 195         }
 196
 197         spin_lock_irqsave(&i2o_drivers_lock, flags);
 198         drv = i2o_drivers[context];
 199         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 200
 201         if (unlikely(!drv)) {
 202                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 203                          context);
 204                 return -EIO;
 205         }
 206
 207         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 208                 struct i2o_device *dev, *tmp;
 209                 struct i2o_event *evt;
 210                 u16 size;
 211                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
 212
 213                 osm_debug("event received from device %d\n", tid);
 214
 215                 if (!drv->event)
 216                         return -EIO;
 217
 218                 /* cut of header from message size (in 32-bit words) */
 219                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
 220
 221                 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 222                 if (!evt)
 223                         return -ENOMEM;
 224
 225                 evt->size = size;
 226                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
 227                 evt->event_indicator = le32_to_cpu(msg->body[0]);
 228                 memcpy(&evt->data, &msg->body[1], size * 4);
 229
 230                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
 231                     if (dev->lct_data.tid == tid) {
 232                         evt->i2o_dev = dev;
 233                         break;
 234                 }
 235
 236                 INIT_WORK(&evt->work, drv->event);
 237                 queue_work(drv->event_queue, &evt->work);
 238                 return 1;
 239         }
 240
 241         if (unlikely(!drv->reply)) {
 242                 osm_debug("%s: Reply to driver %s, but no reply function"
 243                           " defined!\n", c->name, drv->name);
 244                 return -EIO;
 245         }
 246
 247         return drv->reply(c, m, msg);
 248 }
 249
 250 /**
 251  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 252  *      @c: newly added controller
 253  *
 254  *      Send notifications to all registered drivers that a new controller was
 255  *      added.
 256  */
 257 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 258 {
 259         int i;
 260         struct i2o_driver *drv;
 261
 262         for (i = 0; i < i2o_max_drivers; i++) {
 263                 drv = i2o_drivers[i];
 264
 265                 if (drv)
 266                         i2o_driver_notify_controller_add(drv, c);
 267         }
 268 }
 269
 270 /**
 271  *      i2o_driver_notify_controller_remove_all - Send notify of removed controller
 272  *      @c: controller that is being removed
 273  *
 274  *      Send notifications to all registered drivers that a controller was
 275  *      removed.
 276  */
 277 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 278 {
 279         int i;
 280         struct i2o_driver *drv;
 281
 282         for (i = 0; i < i2o_max_drivers; i++) {
 283                 drv = i2o_drivers[i];
 284
 285                 if (drv)
 286                         i2o_driver_notify_controller_remove(drv, c);
 287         }
 288 }
 289
 290 /**
 291  *      i2o_driver_notify_device_add_all - Send notify of added device
 292  *      @i2o_dev: newly added I2O device
 293  *
 294  *      Send notifications to all registered drivers that a device was added.
 295  */
 296 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 297 {
 298         int i;
 299         struct i2o_driver *drv;
 300
 301         for (i = 0; i < i2o_max_drivers; i++) {
 302                 drv = i2o_drivers[i];
 303
 304                 if (drv)
 305                         i2o_driver_notify_device_add(drv, i2o_dev);
 306         }
 307 }
 308
 309 /**
 310  *      i2o_driver_notify_device_remove_all - Send notify of removed device
 311  *      @i2o_dev: device that is being removed
 312  *
 313  *      Send notifications to all registered drivers that a device was removed.
 314  */
 315 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 316 {
 317         int i;
 318         struct i2o_driver *drv;
 319
 320         for (i = 0; i < i2o_max_drivers; i++) {
 321                 drv = i2o_drivers[i];
 322
 323                 if (drv)
 324                         i2o_driver_notify_device_remove(drv, i2o_dev);
 325         }
 326 }
 327
 328 /**
 329  *      i2o_driver_init - initialize I2O drivers (OSMs)
 330  *
 331  *      Registers the I2O bus and allocate memory for the array of OSMs.
 332  *
 333  *      Returns 0 on success or negative error code on failure.
 334  */
 335 int __init i2o_driver_init(void)
 336 {
 337         int rc = 0;
 338
 339         spin_lock_init(&i2o_drivers_lock);
 340
 341         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
 342                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
 343                          i2o_max_drivers);
 344                 i2o_max_drivers = I2O_MAX_DRIVERS;
 345         }
 346         osm_info("max drivers = %d\n", i2o_max_drivers);
 347
 348         i2o_drivers =
 349             kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
 350         if (!i2o_drivers)
 351                 return -ENOMEM;
 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 frees driver array.
 365  */
 366 void 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);