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 "core.h"
  21
  22 #define OSM_NAME        "i2o"
  23
  24 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
  25 static unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
  26 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
  27 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
  28
  29 /* I2O drivers lock and array */
  30 static spinlock_t i2o_drivers_lock;
  31 static struct i2o_driver **i2o_drivers;
  32
  33 /**
  34  *      i2o_bus_match - Tell if a I2O device class id match the class ids of
  35  *                      the I2O driver (OSM)
  36  *
  37  *      @dev: device which should be verified
  38  *      @drv: the driver to match against
  39  *
  40  *      Used by the bus to check if the driver wants to handle the device.
  41  *
  42  *      Returns 1 if the class ids of the driver match the class id of the
  43  *      device, otherwise 0.
  44  */
  45 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
  46 {
  47         struct i2o_device *i2o_dev = to_i2o_device(dev);
  48         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
  49         struct i2o_class_id *ids = i2o_drv->classes;
  50
  51         if (ids)
  52                 while (ids->class_id != I2O_CLASS_END) {
  53                         if (ids->class_id == i2o_dev->lct_data.class_id)
  54                                 return 1;
  55                         ids++;
  56                 }
  57         return 0;
  58 };
  59
  60 /* I2O bus type */
  61 struct bus_type i2o_bus_type = {
  62         .name = "i2o",
  63         .match = i2o_bus_match,
  64 };
  65
  66 /**
  67  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
  68  *      @drv: I2O driver which should be registered
  69  *
  70  *      Registers the OSM drv in the I2O core and creates an event queues if
  71  *      necessary.
  72  *
  73  *      Returns 0 on success or negative error code on failure.
  74  */
  75 int i2o_driver_register(struct i2o_driver *drv)
  76 {
  77         struct i2o_controller *c;
  78         int i;
  79         int rc = 0;
  80         unsigned long flags;
  81
  82         osm_debug("Register driver %s\n", drv->name);
  83
  84         if (drv->event) {
  85                 drv->event_queue = create_workqueue(drv->name);
  86                 if (!drv->event_queue) {
  87                         osm_err("Could not initialize event queue for driver "
  88                                 "%s\n", drv->name);
  89                         return -EFAULT;
  90                 }
  91                 osm_debug("Event queue initialized for driver %s\n", drv->name);
  92         } else
  93                 drv->event_queue = NULL;
  94
  95         drv->driver.name = drv->name;
  96         drv->driver.bus = &i2o_bus_type;
  97
  98         spin_lock_irqsave(&i2o_drivers_lock, flags);
  99
 100         for (i = 0; i2o_drivers[i]; i++)
 101                 if (i >= i2o_max_drivers) {
 102                         osm_err("too many drivers registered, increase "
 103                                 "max_drivers\n");
 104                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 105                         return -EFAULT;
 106                 }
 107
 108         drv->context = i;
 109         i2o_drivers[i] = drv;
 110
 111         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 112
 113         osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
 114
 115         list_for_each_entry(c, &i2o_controllers, list) {
 116                 struct i2o_device *i2o_dev;
 117
 118                 i2o_driver_notify_controller_add(drv, c);
 119                 list_for_each_entry(i2o_dev, &c->devices, list)
 120                     i2o_driver_notify_device_add(drv, i2o_dev);
 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         osm_debug("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                 osm_debug("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 {
 181         struct i2o_driver *drv;
 182         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
 183         u32 context = le32_to_cpu(msg->u.s.icntxt);
 184         unsigned long flags;
 185
 186         if (unlikely(context >= i2o_max_drivers)) {
 187                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 188                          context);
 189                 return -EIO;
 190         }
 191
 192         spin_lock_irqsave(&i2o_drivers_lock, flags);
 193         drv = i2o_drivers[context];
 194         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 195
 196         if (unlikely(!drv)) {
 197                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 198                          context);
 199                 return -EIO;
 200         }
 201
 202         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 203                 struct i2o_device *dev, *tmp;
 204                 struct i2o_event *evt;
 205                 u16 size;
 206                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
 207
 208                 osm_debug("event received from device %d\n", tid);
 209
 210                 if (!drv->event)
 211                         return -EIO;
 212
 213                 /* cut of header from message size (in 32-bit words) */
 214                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
 215
 216                 evt = kmalloc(size * 4 + sizeof(*evt), GFP_ATOMIC | __GFP_ZERO);
 217                 if (!evt)
 218                         return -ENOMEM;
 219
 220                 evt->size = size;
 221                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
 222                 evt->event_indicator = le32_to_cpu(msg->body[0]);
 223                 memcpy(&evt->tcntxt, &msg->u.s.tcntxt, size * 4);
 224
 225                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
 226                     if (dev->lct_data.tid == tid) {
 227                         evt->i2o_dev = dev;
 228                         break;
 229                 }
 230
 231                 INIT_WORK(&evt->work, (void (*)(void *))drv->event, evt);
 232                 queue_work(drv->event_queue, &evt->work);
 233                 return 1;
 234         }
 235
 236         if (unlikely(!drv->reply)) {
 237                 osm_debug("%s: Reply to driver %s, but no reply function"
 238                           " defined!\n", c->name, drv->name);
 239                 return -EIO;
 240         }
 241
 242         return drv->reply(c, m, msg);
 243 }
 244
 245 /**
 246  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 247  *                                             to all I2O drivers
 248  *
 249  *      Send notifications to all registered drivers that a new controller was
 250  *      added.
 251  */
 252 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 253 {
 254         int i;
 255         struct i2o_driver *drv;
 256
 257         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 258                 drv = i2o_drivers[i];
 259
 260                 if (drv)
 261                         i2o_driver_notify_controller_add(drv, c);
 262         }
 263 }
 264
 265 /**
 266  *      i2o_driver_notify_controller_remove_all - Send notify of removed
 267  *                                                controller to all I2O drivers
 268  *
 269  *      Send notifications to all registered drivers that a controller was
 270  *      removed.
 271  */
 272 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 273 {
 274         int i;
 275         struct i2o_driver *drv;
 276
 277         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 278                 drv = i2o_drivers[i];
 279
 280                 if (drv)
 281                         i2o_driver_notify_controller_remove(drv, c);
 282         }
 283 }
 284
 285 /**
 286  *      i2o_driver_notify_device_add_all - Send notify of added device to all
 287  *                                         I2O drivers
 288  *
 289  *      Send notifications to all registered drivers that a device was added.
 290  */
 291 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 292 {
 293         int i;
 294         struct i2o_driver *drv;
 295
 296         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 297                 drv = i2o_drivers[i];
 298
 299                 if (drv)
 300                         i2o_driver_notify_device_add(drv, i2o_dev);
 301         }
 302 }
 303
 304 /**
 305  *      i2o_driver_notify_device_remove_all - Send notify of removed device to
 306  *                                            all I2O drivers
 307  *
 308  *      Send notifications to all registered drivers that a device was removed.
 309  */
 310 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 311 {
 312         int i;
 313         struct i2o_driver *drv;
 314
 315         for (i = 0; i < I2O_MAX_DRIVERS; i++) {
 316                 drv = i2o_drivers[i];
 317
 318                 if (drv)
 319                         i2o_driver_notify_device_remove(drv, i2o_dev);
 320         }
 321 }
 322
 323 /**
 324  *      i2o_driver_init - initialize I2O drivers (OSMs)
 325  *
 326  *      Registers the I2O bus and allocate memory for the array of OSMs.
 327  *
 328  *      Returns 0 on success or negative error code on failure.
 329  */
 330 int __init i2o_driver_init(void)
 331 {
 332         int rc = 0;
 333
 334         spin_lock_init(&i2o_drivers_lock);
 335
 336         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
 337             ((i2o_max_drivers ^ (i2o_max_drivers - 1)) !=
 338              (2 * i2o_max_drivers - 1))) {
 339                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
 340                          "a power of 2\n", i2o_max_drivers);
 341                 i2o_max_drivers = I2O_MAX_DRIVERS;
 342         }
 343         osm_info("max drivers = %d\n", i2o_max_drivers);
 344
 345         i2o_drivers =
 346             kmalloc(i2o_max_drivers * sizeof(*i2o_drivers), GFP_KERNEL);
 347         if (!i2o_drivers)
 348                 return -ENOMEM;
 349
 350         memset(i2o_drivers, 0, i2o_max_drivers * sizeof(*i2o_drivers));
 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 free driver array.
 364  */
 365 void __exit 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);