kernel/drivers/s390/scsi/zfcp_ccw.c

   1 /*
   2  * zfcp device driver
   3  *
   4  * Registration and callback for the s390 common I/O layer.
   5  *
   6  * Copyright IBM Corp. 2002, 2010
   7  */
   8
   9 #define KMSG_COMPONENT "zfcp"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include <linux/module.h>
  13 #include "zfcp_ext.h"
  14 #include "zfcp_reqlist.h"
  15
  16 #define ZFCP_MODEL_PRIV 0x4
  17
  18 static DEFINE_SPINLOCK(zfcp_ccw_adapter_ref_lock);
  19
  20 struct zfcp_adapter *zfcp_ccw_adapter_by_cdev(struct ccw_device *cdev)
  21 {
  22         struct zfcp_adapter *adapter;
  23         unsigned long flags;
  24
  25         spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
  26         adapter = dev_get_drvdata(&cdev->dev);
  27         if (adapter)
  28                 kref_get(&adapter->ref);
  29         spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
  30         return adapter;
  31 }
  32
  33 void zfcp_ccw_adapter_put(struct zfcp_adapter *adapter)
  34 {
  35         unsigned long flags;
  36
  37         spin_lock_irqsave(&zfcp_ccw_adapter_ref_lock, flags);
  38         kref_put(&adapter->ref, zfcp_adapter_release);
  39         spin_unlock_irqrestore(&zfcp_ccw_adapter_ref_lock, flags);
  40 }
  41
  42 /**
  43  * zfcp_ccw_activate - activate adapter and wait for it to finish
  44  * @cdev: pointer to belonging ccw device
  45  * @clear: Status flags to clear.
  46  * @tag: s390dbf trace record tag
  47  */
  48 static int zfcp_ccw_activate(struct ccw_device *cdev, int clear, char *tag)
  49 {
  50         struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
  51
  52         if (!adapter)
  53                 return 0;
  54
  55         zfcp_erp_clear_adapter_status(adapter, clear);
  56         zfcp_erp_set_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING);
  57         zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
  58                                 tag);
  59
  60         /*
  61          * We want to scan ports here, with some random backoff and without
  62          * rate limit. Recovery has already scheduled a port scan for us,
  63          * but with both random delay and rate limit. Nevertheless we get
  64          * what we want here by flushing the scheduled work after sleeping
  65          * an equivalent random time.
  66          * Let the port scan random delay elapse first. If recovery finishes
  67          * up to that point in time, that would be perfect for both recovery
  68          * and port scan. If not, i.e. recovery takes ages, there was no
  69          * point in waiting a random delay on top of the time consumed by
  70          * recovery.
  71          */
  72         msleep(zfcp_fc_port_scan_backoff());
  73         zfcp_erp_wait(adapter);
  74         flush_delayed_work(&adapter->scan_work);
  75
  76         zfcp_ccw_adapter_put(adapter);
  77
  78         return 0;
  79 }
  80
  81 static struct ccw_device_id zfcp_ccw_device_id[] = {
  82         { CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, 0x3) },
  83         { CCW_DEVICE_DEVTYPE(0x1731, 0x3, 0x1732, ZFCP_MODEL_PRIV) },
  84         {},
  85 };
  86 MODULE_DEVICE_TABLE(ccw, zfcp_ccw_device_id);
  87
  88 /**
  89  * zfcp_ccw_probe - probe function of zfcp driver
  90  * @cdev: pointer to belonging ccw device
  91  *
  92  * This function gets called by the common i/o layer for each FCP
  93  * device found on the current system. This is only a stub to make cio
  94  * work: To only allocate adapter resources for devices actually used,
  95  * the allocation is deferred to the first call to ccw_set_online.
  96  */
  97 static int zfcp_ccw_probe(struct ccw_device *cdev)
  98 {
  99         return 0;
 100 }
 101
 102 /**
 103  * zfcp_ccw_remove - remove function of zfcp driver
 104  * @cdev: pointer to belonging ccw device
 105  *
 106  * This function gets called by the common i/o layer and removes an adapter
 107  * from the system. Task of this function is to get rid of all units and
 108  * ports that belong to this adapter. And in addition all resources of this
 109  * adapter will be freed too.
 110  */
 111 static void zfcp_ccw_remove(struct ccw_device *cdev)
 112 {
 113         struct zfcp_adapter *adapter;
 114         struct zfcp_port *port, *p;
 115         struct zfcp_unit *unit, *u;
 116         LIST_HEAD(unit_remove_lh);
 117         LIST_HEAD(port_remove_lh);
 118
 119         ccw_device_set_offline(cdev);
 120
 121         adapter = zfcp_ccw_adapter_by_cdev(cdev);
 122         if (!adapter)
 123                 return;
 124
 125         write_lock_irq(&adapter->port_list_lock);
 126         list_for_each_entry_safe(port, p, &adapter->port_list, list) {
 127                 write_lock(&port->unit_list_lock);
 128                 list_for_each_entry_safe(unit, u, &port->unit_list, list)
 129                         list_move(&unit->list, &unit_remove_lh);
 130                 write_unlock(&port->unit_list_lock);
 131                 list_move(&port->list, &port_remove_lh);
 132         }
 133         write_unlock_irq(&adapter->port_list_lock);
 134         zfcp_ccw_adapter_put(adapter); /* put from zfcp_ccw_adapter_by_cdev */
 135
 136         list_for_each_entry_safe(unit, u, &unit_remove_lh, list)
 137                 device_unregister(&unit->dev);
 138
 139         list_for_each_entry_safe(port, p, &port_remove_lh, list)
 140                 device_unregister(&port->dev);
 141
 142         zfcp_adapter_unregister(adapter);
 143 }
 144
 145 /**
 146  * zfcp_ccw_set_online - set_online function of zfcp driver
 147  * @cdev: pointer to belonging ccw device
 148  *
 149  * This function gets called by the common i/o layer and sets an
 150  * adapter into state online.  The first call will allocate all
 151  * adapter resources that will be retained until the device is removed
 152  * via zfcp_ccw_remove.
 153  *
 154  * Setting an fcp device online means that it will be registered with
 155  * the SCSI stack, that the QDIO queues will be set up and that the
 156  * adapter will be opened.
 157  */
 158 static int zfcp_ccw_set_online(struct ccw_device *cdev)
 159 {
 160         struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
 161
 162         if (!adapter) {
 163                 adapter = zfcp_adapter_enqueue(cdev);
 164
 165                 if (IS_ERR(adapter)) {
 166                         dev_err(&cdev->dev,
 167                                 "Setting up data structures for the "
 168                                 "FCP adapter failed\n");
 169                         return PTR_ERR(adapter);
 170                 }
 171                 kref_get(&adapter->ref);
 172         }
 173
 174         /* initialize request counter */
 175         BUG_ON(!zfcp_reqlist_isempty(adapter->req_list));
 176         adapter->req_no = 0;
 177
 178         zfcp_ccw_activate(cdev, 0, "ccsonl1");
 179
 180         /*
 181          * We want to scan ports here, always, with some random delay and
 182          * without rate limit - basically what zfcp_ccw_activate() has
 183          * achieved for us. Not quite! That port scan depended on
 184          * !no_auto_port_rescan. So let's cover the no_auto_port_rescan
 185          * case here to make sure a port scan is done unconditionally.
 186          * Since zfcp_ccw_activate() has waited the desired random time,
 187          * we can immediately schedule and flush a port scan for the
 188          * remaining cases.
 189          */
 190         zfcp_fc_inverse_conditional_port_scan(adapter);
 191         flush_delayed_work(&adapter->scan_work);
 192         zfcp_ccw_adapter_put(adapter);
 193         return 0;
 194 }
 195
 196 /**
 197  * zfcp_ccw_offline_sync - shut down adapter and wait for it to finish
 198  * @cdev: pointer to belonging ccw device
 199  * @set: Status flags to set.
 200  * @tag: s390dbf trace record tag
 201  *
 202  * This function gets called by the common i/o layer and sets an adapter
 203  * into state offline.
 204  */
 205 static int zfcp_ccw_offline_sync(struct ccw_device *cdev, int set, char *tag)
 206 {
 207         struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
 208
 209         if (!adapter)
 210                 return 0;
 211
 212         zfcp_erp_set_adapter_status(adapter, set);
 213         zfcp_erp_adapter_shutdown(adapter, 0, tag);
 214         zfcp_erp_wait(adapter);
 215
 216         zfcp_ccw_adapter_put(adapter);
 217         return 0;
 218 }
 219
 220 /**
 221  * zfcp_ccw_set_offline - set_offline function of zfcp driver
 222  * @cdev: pointer to belonging ccw device
 223  *
 224  * This function gets called by the common i/o layer and sets an adapter
 225  * into state offline.
 226  */
 227 static int zfcp_ccw_set_offline(struct ccw_device *cdev)
 228 {
 229         return zfcp_ccw_offline_sync(cdev, 0, "ccsoff1");
 230 }
 231
 232 /**
 233  * zfcp_ccw_notify - ccw notify function
 234  * @cdev: pointer to belonging ccw device
 235  * @event: indicates if adapter was detached or attached
 236  *
 237  * This function gets called by the common i/o layer if an adapter has gone
 238  * or reappeared.
 239  */
 240 static int zfcp_ccw_notify(struct ccw_device *cdev, int event)
 241 {
 242         struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
 243
 244         if (!adapter)
 245                 return 1;
 246
 247         switch (event) {
 248         case CIO_GONE:
 249                 if (atomic_read(&adapter->status) &
 250                     ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
 251                         zfcp_dbf_hba_basic("ccnigo1", adapter);
 252                         break;
 253                 }
 254                 dev_warn(&cdev->dev, "The FCP device has been detached\n");
 255                 zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti1");
 256                 break;
 257         case CIO_NO_PATH:
 258                 dev_warn(&cdev->dev,
 259                          "The CHPID for the FCP device is offline\n");
 260                 zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti2");
 261                 break;
 262         case CIO_OPER:
 263                 if (atomic_read(&adapter->status) &
 264                     ZFCP_STATUS_ADAPTER_SUSPENDED) { /* notification ignore */
 265                         zfcp_dbf_hba_basic("ccniop1", adapter);
 266                         break;
 267                 }
 268                 dev_info(&cdev->dev, "The FCP device is operational again\n");
 269                 zfcp_erp_set_adapter_status(adapter,
 270                                             ZFCP_STATUS_COMMON_RUNNING);
 271                 zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
 272                                         "ccnoti4");
 273                 break;
 274         case CIO_BOXED:
 275                 dev_warn(&cdev->dev, "The FCP device did not respond within "
 276                                      "the specified time\n");
 277                 zfcp_erp_adapter_shutdown(adapter, 0, "ccnoti5");
 278                 break;
 279         }
 280
 281         zfcp_ccw_adapter_put(adapter);
 282         return 1;
 283 }
 284
 285 /**
 286  * zfcp_ccw_shutdown - handle shutdown from cio
 287  * @cdev: device for adapter to shutdown.
 288  */
 289 static void zfcp_ccw_shutdown(struct ccw_device *cdev)
 290 {
 291         struct zfcp_adapter *adapter = zfcp_ccw_adapter_by_cdev(cdev);
 292
 293         if (!adapter)
 294                 return;
 295
 296         zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1");
 297         zfcp_erp_wait(adapter);
 298         zfcp_erp_thread_kill(adapter);
 299
 300         zfcp_ccw_adapter_put(adapter);
 301 }
 302
 303 static int zfcp_ccw_suspend(struct ccw_device *cdev)
 304 {
 305         zfcp_ccw_offline_sync(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccsusp1");
 306         return 0;
 307 }
 308
 309 static int zfcp_ccw_thaw(struct ccw_device *cdev)
 310 {
 311         /* trace records for thaw and final shutdown during suspend
 312            can only be found in system dump until the end of suspend
 313            but not after resume because it's based on the memory image
 314            right after the very first suspend (freeze) callback */
 315         zfcp_ccw_activate(cdev, 0, "ccthaw1");
 316         return 0;
 317 }
 318
 319 static int zfcp_ccw_resume(struct ccw_device *cdev)
 320 {
 321         zfcp_ccw_activate(cdev, ZFCP_STATUS_ADAPTER_SUSPENDED, "ccresu1");
 322         return 0;
 323 }
 324
 325 struct ccw_driver zfcp_ccw_driver = {
 326         .driver = {
 327                 .owner  = THIS_MODULE,
 328                 .name   = "zfcp",
 329         },
 330         .ids         = zfcp_ccw_device_id,
 331         .probe       = zfcp_ccw_probe,
 332         .remove      = zfcp_ccw_remove,
 333         .set_online  = zfcp_ccw_set_online,
 334         .set_offline = zfcp_ccw_set_offline,
 335         .notify      = zfcp_ccw_notify,
 336         .shutdown    = zfcp_ccw_shutdown,
 337         .freeze      = zfcp_ccw_suspend,
 338         .thaw        = zfcp_ccw_thaw,
 339         .restore     = zfcp_ccw_resume,
 340 };