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