Pileus Git - ~andy/linux/blob - 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 <linux/log2.h>
  24 #include "core.h"
  25
  26 #define OSM_NAME        "i2o"
  27
  28 /* max_drivers - Maximum I2O drivers (OSMs) which could be registered */
  29 static unsigned int i2o_max_drivers = I2O_MAX_DRIVERS;
  30 module_param_named(max_drivers, i2o_max_drivers, uint, 0);
  31 MODULE_PARM_DESC(max_drivers, "maximum number of OSM's to support");
  32
  33 /* I2O drivers lock and array */
  34 static spinlock_t i2o_drivers_lock;
  35 static struct i2o_driver **i2o_drivers;
  36
  37 /**
  38  *      i2o_bus_match - Tell if I2O device class id matches the class ids of the I2O driver (OSM)
  39  *      @dev: device which should be verified
  40  *      @drv: the driver to match against
  41  *
  42  *      Used by the bus to check if the driver wants to handle the device.
  43  *
  44  *      Returns 1 if the class ids of the driver match the class id of the
  45  *      device, otherwise 0.
  46  */
  47 static int i2o_bus_match(struct device *dev, struct device_driver *drv)
  48 {
  49         struct i2o_device *i2o_dev = to_i2o_device(dev);
  50         struct i2o_driver *i2o_drv = to_i2o_driver(drv);
  51         struct i2o_class_id *ids = i2o_drv->classes;
  52
  53         if (ids)
  54                 while (ids->class_id != I2O_CLASS_END) {
  55                         if (ids->class_id == i2o_dev->lct_data.class_id)
  56                                 return 1;
  57                         ids++;
  58                 }
  59         return 0;
  60 };
  61
  62 /* I2O bus type */
  63 struct bus_type i2o_bus_type = {
  64         .name = "i2o",
  65         .match = i2o_bus_match,
  66         .dev_attrs = i2o_device_attrs
  67 };
  68
  69 /**
  70  *      i2o_driver_register - Register a I2O driver (OSM) in the I2O core
  71  *      @drv: I2O driver which should be registered
  72  *
  73  *      Registers the OSM drv in the I2O core and creates an event queues if
  74  *      necessary.
  75  *
  76  *      Returns 0 on success or negative error code on failure.
  77  */
  78 int i2o_driver_register(struct i2o_driver *drv)
  79 {
  80         struct i2o_controller *c;
  81         int i;
  82         int rc = 0;
  83         unsigned long flags;
  84
  85         osm_debug("Register driver %s\n", drv->name);
  86
  87         if (drv->event) {
  88                 drv->event_queue = create_workqueue(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  *      @msg: I2O message to be delivered
 178  *
 179  *      The reply is delivered to the driver from which the original message
 180  *      was. This function is only called from interrupt context.
 181  *
 182  *      Returns 0 on success and the message should not be flushed. Returns > 0
 183  *      on success and if the message should be flushed afterwords. Returns
 184  *      negative error code on failure (the message will be flushed too).
 185  */
 186 int i2o_driver_dispatch(struct i2o_controller *c, u32 m)
 187 {
 188         struct i2o_driver *drv;
 189         struct i2o_message *msg = i2o_msg_out_to_virt(c, m);
 190         u32 context = le32_to_cpu(msg->u.s.icntxt);
 191         unsigned long flags;
 192
 193         if (unlikely(context >= i2o_max_drivers)) {
 194                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 195                          context);
 196                 return -EIO;
 197         }
 198
 199         spin_lock_irqsave(&i2o_drivers_lock, flags);
 200         drv = i2o_drivers[context];
 201         spin_unlock_irqrestore(&i2o_drivers_lock, flags);
 202
 203         if (unlikely(!drv)) {
 204                 osm_warn("%s: Spurious reply to unknown driver %d\n", c->name,
 205                          context);
 206                 return -EIO;
 207         }
 208
 209         if ((le32_to_cpu(msg->u.head[1]) >> 24) == I2O_CMD_UTIL_EVT_REGISTER) {
 210                 struct i2o_device *dev, *tmp;
 211                 struct i2o_event *evt;
 212                 u16 size;
 213                 u16 tid = le32_to_cpu(msg->u.head[1]) & 0xfff;
 214
 215                 osm_debug("event received from device %d\n", tid);
 216
 217                 if (!drv->event)
 218                         return -EIO;
 219
 220                 /* cut of header from message size (in 32-bit words) */
 221                 size = (le32_to_cpu(msg->u.head[0]) >> 16) - 5;
 222
 223                 evt = kzalloc(size * 4 + sizeof(*evt), GFP_ATOMIC);
 224                 if (!evt)
 225                         return -ENOMEM;
 226
 227                 evt->size = size;
 228                 evt->tcntxt = le32_to_cpu(msg->u.s.tcntxt);
 229                 evt->event_indicator = le32_to_cpu(msg->body[0]);
 230                 memcpy(&evt->data, &msg->body[1], size * 4);
 231
 232                 list_for_each_entry_safe(dev, tmp, &c->devices, list)
 233                     if (dev->lct_data.tid == tid) {
 234                         evt->i2o_dev = dev;
 235                         break;
 236                 }
 237
 238                 INIT_WORK(&evt->work, drv->event);
 239                 queue_work(drv->event_queue, &evt->work);
 240                 return 1;
 241         }
 242
 243         if (unlikely(!drv->reply)) {
 244                 osm_debug("%s: Reply to driver %s, but no reply function"
 245                           " defined!\n", c->name, drv->name);
 246                 return -EIO;
 247         }
 248
 249         return drv->reply(c, m, msg);
 250 }
 251
 252 /**
 253  *      i2o_driver_notify_controller_add_all - Send notify of added controller
 254  *      @c: newly added controller
 255  *
 256  *      Send notifications to all registered drivers that a new controller was
 257  *      added.
 258  */
 259 void i2o_driver_notify_controller_add_all(struct i2o_controller *c)
 260 {
 261         int i;
 262         struct i2o_driver *drv;
 263
 264         for (i = 0; i < i2o_max_drivers; i++) {
 265                 drv = i2o_drivers[i];
 266
 267                 if (drv)
 268                         i2o_driver_notify_controller_add(drv, c);
 269         }
 270 }
 271
 272 /**
 273  *      i2o_driver_notify_controller_remove_all - Send notify of removed controller
 274  *      @c: controller that is being removed
 275  *
 276  *      Send notifications to all registered drivers that a controller was
 277  *      removed.
 278  */
 279 void i2o_driver_notify_controller_remove_all(struct i2o_controller *c)
 280 {
 281         int i;
 282         struct i2o_driver *drv;
 283
 284         for (i = 0; i < i2o_max_drivers; i++) {
 285                 drv = i2o_drivers[i];
 286
 287                 if (drv)
 288                         i2o_driver_notify_controller_remove(drv, c);
 289         }
 290 }
 291
 292 /**
 293  *      i2o_driver_notify_device_add_all - Send notify of added device
 294  *      @i2o_dev: newly added I2O device
 295  *
 296  *      Send notifications to all registered drivers that a device was added.
 297  */
 298 void i2o_driver_notify_device_add_all(struct i2o_device *i2o_dev)
 299 {
 300         int i;
 301         struct i2o_driver *drv;
 302
 303         for (i = 0; i < i2o_max_drivers; i++) {
 304                 drv = i2o_drivers[i];
 305
 306                 if (drv)
 307                         i2o_driver_notify_device_add(drv, i2o_dev);
 308         }
 309 }
 310
 311 /**
 312  *      i2o_driver_notify_device_remove_all - Send notify of removed device
 313  *      @i2o_dev: device that is being removed
 314  *
 315  *      Send notifications to all registered drivers that a device was removed.
 316  */
 317 void i2o_driver_notify_device_remove_all(struct i2o_device *i2o_dev)
 318 {
 319         int i;
 320         struct i2o_driver *drv;
 321
 322         for (i = 0; i < i2o_max_drivers; i++) {
 323                 drv = i2o_drivers[i];
 324
 325                 if (drv)
 326                         i2o_driver_notify_device_remove(drv, i2o_dev);
 327         }
 328 }
 329
 330 /**
 331  *      i2o_driver_init - initialize I2O drivers (OSMs)
 332  *
 333  *      Registers the I2O bus and allocate memory for the array of OSMs.
 334  *
 335  *      Returns 0 on success or negative error code on failure.
 336  */
 337 int __init i2o_driver_init(void)
 338 {
 339         int rc = 0;
 340
 341         spin_lock_init(&i2o_drivers_lock);
 342
 343         if ((i2o_max_drivers < 2) || (i2o_max_drivers > 64) ||
 344             !is_power_of_2(i2o_max_drivers)) {
 345                 osm_warn("max_drivers set to %d, but must be >=2 and <= 64 and "
 346                          "a power of 2\n", i2o_max_drivers);
 347                 i2o_max_drivers = I2O_MAX_DRIVERS;
 348         }
 349         osm_info("max drivers = %d\n", i2o_max_drivers);
 350
 351         i2o_drivers =
 352             kcalloc(i2o_max_drivers, sizeof(*i2o_drivers), GFP_KERNEL);
 353         if (!i2o_drivers)
 354                 return -ENOMEM;
 355
 356         rc = bus_register(&i2o_bus_type);
 357
 358         if (rc < 0)
 359                 kfree(i2o_drivers);
 360
 361         return rc;
 362 };
 363
 364 /**
 365  *      i2o_driver_exit - clean up I2O drivers (OSMs)
 366  *
 367  *      Unregisters the I2O bus and frees driver array.
 368  */
 369 void i2o_driver_exit(void)
 370 {
 371         bus_unregister(&i2o_bus_type);
 372         kfree(i2o_drivers);
 373 };
 374
 375 EXPORT_SYMBOL(i2o_driver_register);
 376 EXPORT_SYMBOL(i2o_driver_unregister);
 377 EXPORT_SYMBOL(i2o_driver_notify_controller_add_all);
 378 EXPORT_SYMBOL(i2o_driver_notify_controller_remove_all);
 379 EXPORT_SYMBOL(i2o_driver_notify_device_add_all);
 380 EXPORT_SYMBOL(i2o_driver_notify_device_remove_all);