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