kernel/drivers/staging/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 "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_groups = i2o_device_groups,
  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 = alloc_workqueue("%s", WQ_MEM_RECLAIM, 1,
  88                                                    drv->name);
  89                 if (!drv->event_queue) {
  90                         osm_err("Could not initialize event queue for driver "
  91                                 "%s\n", drv->name);
  92                         return -EFAULT;
  93                 }
  94                 osm_debug("Event queue initialized for driver %s\n", drv->name);
  95         } else
  96                 drv->event_queue = NULL;
  97
  98         drv->driver.name = drv->name;
  99         drv->driver.bus = &i2o_bus_type;
 100
 101         spin_lock_irqsave(&i2o_drivers_lock, flags);
 102
 103         for (i = 0; i2o_drivers[i]; i++)
 104                 if (i >= i2o_max_drivers) {
 105                         osm_err("too many drivers registered, increase max_drivers\n");
 106                         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 107                         rc = -EFAULT;
 108                         goto out;
 109                 }
 110
 111         drv->context = i;
 112         i2o_drivers[i] = drv;
 113
 114         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 115
 116         osm_debug("driver %s gets context id %d\n", drv->name, drv->context);
 117
 118         list_for_each_entry(c, &i2o_controllers, list) {
 119                 struct i2o_device *i2o_dev;
 120
 121                 i2o_driver_notify_controller_add(drv, c);
 122                 list_for_each_entry(i2o_dev, &c->devices, list)
 123                     i2o_driver_notify_device_add(drv, i2o_dev);
 124         }
 125
 126         rc = driver_register(&drv->driver);
 127         if (rc)
 128                 goto out;
 129
 130         return 0;
 131 out:
 132         if (drv->event_queue) {
 133                 destroy_workqueue(drv->event_queue);
 134                 drv->event_queue = NULL;
 135         }
 136
 137         return rc;
 138 };
 139
 140 /**
 141  *      i2o_driver_unregister - Unregister a I2O driver (OSM) from the I2O core
 142  *      @drv: I2O driver which should be unregistered
 143  *
 144  *      Unregisters the OSM drv from the I2O core and cleanup event queues if
 145  *      necessary.
 146  */
 147 void i2o_driver_unregister(struct i2o_driver *drv)
 148 {
 149         struct i2o_controller *c;
 150         unsigned long flags;
 151
 152         osm_debug("unregister driver %s\n", drv->name);
 153
 154         driver_unregister(&drv->driver);
 155
 156         list_for_each_entry(c, &i2o_controllers, list) {
 157                 struct i2o_device *i2o_dev;
 158
 159                 list_for_each_entry(i2o_dev, &c->devices, list)
 160                     i2o_driver_notify_device_remove(drv, i2o_dev);
 161
 162                 i2o_driver_notify_controller_remove(drv, c);
 163         }
 164
 165         spin_lock_irqsave(&i2o_drivers_lock, flags);
 166         i2o_drivers[drv->context] = NULL;
 167         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 168
 169         if (drv->event_queue) {
 170                 destroy_workqueue(drv->event_queue);
 171                 drv->event_queue = NULL;
 172                 osm_debug("event queue removed for %s\n", drv->name);
 173         }
 174 };
 175
 176 /**
 177  *      i2o_driver_dispatch - dispatch an I2O reply message
 178  *      @c: I2O controller of the message
 179  *      @m: I2O message number
 180  *
 181  *      The reply is delivered to the driver from which the original message
 182  *      was. This function is only called from interrupt context.
 183  *
 184  *      Returns 0 on success and the message should not be flushed. Returns > 0
 185  *      on success and if the message should be flushed afterwords. Returns
 186  *      negative error code on failure (the message will be flushed too).
 187  */
 188 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
 189 {
 190         struct i2o_driver *drv;
 191         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
 192         u32 context = le32_to_cpu(msg->u.s.icntxt);
 193         unsigned long flags;
 194
 195         if (unlikely(context >= i2o_max_drivers)) {
 196                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 197                          context);
 198                 return -EIO;
 199         }
 200
 201         spin_lock_irqsave(&i2o_drivers_lock, flags);
 202         drv = i2o_drivers[context];
 203         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 204
 205         if (unlikely(!drv)) {
 206                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 207                          context);
 208                 return -EIO;
 209         }
 210
 211         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 212                 struct i2o_device *dev, *tmp;
 213                 struct i2o_event *evt;
 214                 u16 size;
 215                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
 216
 217                 osm_debug("event received from device %d\n", tid);
 218
 219                 if (!drv->event)
 220                         return -EIO;
 221
 222                 /* cut of header from message size (in 32-bit words) */
 223                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
 224
 225                 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 226                 if (!evt)
 227                         return -ENOMEM;
 228
 229                 evt->size = size;
 230                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
 231                 evt->event_indicator = le32_to_cpu(msg->body[0]);
 232                 memcpy(&evt->data, &msg->body[1], size * 4);
 233
 234                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
 235                     if (dev->lct_data.tid == tid) {
 236                         evt->i2o_dev = dev;
 237                         break;
 238                 }
 239
 240                 INIT_WORK(&evt->work, drv->event);
 241                 queue_work(drv->event_queue, &evt->work);
 242                 return 1;
 243         }
 244
 245         if (unlikely(!drv->reply)) {
 246                 osm_debug("%s: Reply to driver %s, but no reply function defined!\n",
 247                         c->name, drv->name);
 248                 return -EIO;
 249         }
 250
 251         return drv->reply(c, m, msg);
 252 }
 253
 254 /**
 255  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 256  *      @c: newly added controller
 257  *
 258  *      Send notifications to all registered drivers that a new controller was
 259  *      added.
 260  */
 261 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 262 {
 263         int i;
 264         struct i2o_driver *drv;
 265
 266         for (i = 0; i < i2o_max_drivers; i++) {
 267                 drv = i2o_drivers[i];
 268
 269                 if (drv)
 270                         i2o_driver_notify_controller_add(drv, c);
 271         }
 272 }
 273
 274 /**
 275  *      i2o_driver_notify_controller_remove_all - Send notify of removed controller
 276  *      @c: controller that is being removed
 277  *
 278  *      Send notifications to all registered drivers that a controller was
 279  *      removed.
 280  */
 281 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 282 {
 283         int i;
 284         struct i2o_driver *drv;
 285
 286         for (i = 0; i < i2o_max_drivers; i++) {
 287                 drv = i2o_drivers[i];
 288
 289                 if (drv)
 290                         i2o_driver_notify_controller_remove(drv, c);
 291         }
 292 }
 293
 294 /**
 295  *      i2o_driver_notify_device_add_all - Send notify of added device
 296  *      @i2o_dev: newly added I2O device
 297  *
 298  *      Send notifications to all registered drivers that a device was added.
 299  */
 300 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 301 {
 302         int i;
 303         struct i2o_driver *drv;
 304
 305         for (i = 0; i < i2o_max_drivers; i++) {
 306                 drv = i2o_drivers[i];
 307
 308                 if (drv)
 309                         i2o_driver_notify_device_add(drv, i2o_dev);
 310         }
 311 }
 312
 313 /**
 314  *      i2o_driver_notify_device_remove_all - Send notify of removed device
 315  *      @i2o_dev: device that is being removed
 316  *
 317  *      Send notifications to all registered drivers that a device was removed.
 318  */
 319 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 320 {
 321         int i;
 322         struct i2o_driver *drv;
 323
 324         for (i = 0; i < i2o_max_drivers; i++) {
 325                 drv = i2o_drivers[i];
 326
 327                 if (drv)
 328                         i2o_driver_notify_device_remove(drv, i2o_dev);
 329         }
 330 }
 331
 332 /**
 333  *      i2o_driver_init - initialize I2O drivers (OSMs)
 334  *
 335  *      Registers the I2O bus and allocate memory for the array of OSMs.
 336  *
 337  *      Returns 0 on success or negative error code on failure.
 338  */
 339 int __init i2o_driver_init(void)
 340 {
 341         int rc = 0;
 342
 343         spin_lock_init(&i2o_drivers_lock);
 344
 345         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64)) {
 346                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64\n",
 347                          i2o_max_drivers);
 348                 i2o_max_drivers = I2O_MAX_DRIVERS;
 349         }
 350         osm_info("max drivers = %d\n", i2o_max_drivers);
 351
 352         i2o_drivers =
 353             kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
 354         if (!i2o_drivers)
 355                 return -ENOMEM;
 356
 357         rc = bus_register(&i2o_bus_type);
 358
 359         if (rc < 0)
 360                 kfree(i2o_drivers);
 361
 362         return rc;
 363 };
 364
 365 /**
 366  *      i2o_driver_exit - clean up I2O drivers (OSMs)
 367  *
 368  *      Unregisters the I2O bus and frees driver array.
 369  */
 370 void i2o_driver_exit(void)
 371 {
 372         bus_unregister(&i2o_bus_type);
 373         kfree(i2o_drivers);
 374 };
 375
 376 EXPORT_SYMBOL(i2o_driver_register);
 377 EXPORT_SYMBOL(i2o_driver_unregister);
 378 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
 379 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
 380 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
 381 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);