[SCSI] zfcp: Dont clear reference from SCSI device to unit
[pandora-kernel.git] / drivers / s390 / scsi / zfcp_scsi.c
1 /*
2  * zfcp device driver
3  *
4  * Interface to Linux SCSI midlayer.
5  *
6  * Copyright IBM Corporation 2002, 2008
7  */
8
9 #include "zfcp_ext.h"
10 #include <asm/atomic.h>
11
12 /* Find start of Sense Information in FCP response unit*/
13 char *zfcp_get_fcp_sns_info_ptr(struct fcp_rsp_iu *fcp_rsp_iu)
14 {
15         char *fcp_sns_info_ptr;
16
17         fcp_sns_info_ptr = (unsigned char *) &fcp_rsp_iu[1];
18         if (fcp_rsp_iu->validity.bits.fcp_rsp_len_valid)
19                 fcp_sns_info_ptr += fcp_rsp_iu->fcp_rsp_len;
20
21         return fcp_sns_info_ptr;
22 }
23
24 static void zfcp_scsi_slave_destroy(struct scsi_device *sdpnt)
25 {
26         struct zfcp_unit *unit = (struct zfcp_unit *) sdpnt->hostdata;
27         atomic_clear_mask(ZFCP_STATUS_UNIT_REGISTERED, &unit->status);
28         unit->device = NULL;
29         zfcp_erp_unit_failed(unit, 12, NULL);
30         zfcp_unit_put(unit);
31 }
32
33 static int zfcp_scsi_slave_configure(struct scsi_device *sdp)
34 {
35         if (sdp->tagged_supported)
36                 scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, 32);
37         else
38                 scsi_adjust_queue_depth(sdp, 0, 1);
39         return 0;
40 }
41
42 static void zfcp_scsi_command_fail(struct scsi_cmnd *scpnt, int result)
43 {
44         set_host_byte(scpnt, result);
45         if ((scpnt->device != NULL) && (scpnt->device->host != NULL))
46                 zfcp_scsi_dbf_event_result("fail", 4,
47                         (struct zfcp_adapter*) scpnt->device->host->hostdata[0],
48                         scpnt, NULL);
49         /* return directly */
50         scpnt->scsi_done(scpnt);
51 }
52
53 static int zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
54                                   void (*done) (struct scsi_cmnd *))
55 {
56         struct zfcp_unit *unit;
57         struct zfcp_adapter *adapter;
58         int    status;
59         int    ret;
60
61         /* reset the status for this request */
62         scpnt->result = 0;
63         scpnt->host_scribble = NULL;
64         scpnt->scsi_done = done;
65
66         /*
67          * figure out adapter and target device
68          * (stored there by zfcp_scsi_slave_alloc)
69          */
70         adapter = (struct zfcp_adapter *) scpnt->device->host->hostdata[0];
71         unit = scpnt->device->hostdata;
72
73         BUG_ON(!adapter || (adapter != unit->port->adapter));
74         BUG_ON(!scpnt->scsi_done);
75
76         if (unlikely(!unit)) {
77                 zfcp_scsi_command_fail(scpnt, DID_NO_CONNECT);
78                 return 0;
79         }
80
81         status = atomic_read(&unit->status);
82         if (unlikely((status & ZFCP_STATUS_COMMON_ERP_FAILED) ||
83                      !(status & ZFCP_STATUS_COMMON_RUNNING))) {
84                 zfcp_scsi_command_fail(scpnt, DID_ERROR);
85                 return 0;;
86         }
87
88         ret = zfcp_fsf_send_fcp_command_task(adapter, unit, scpnt, 0,
89                                              ZFCP_REQ_AUTO_CLEANUP);
90         if (unlikely(ret == -EBUSY))
91                 zfcp_scsi_command_fail(scpnt, DID_NO_CONNECT);
92         else if (unlikely(ret < 0))
93                 return SCSI_MLQUEUE_HOST_BUSY;
94
95         return ret;
96 }
97
98 static struct zfcp_unit *zfcp_unit_lookup(struct zfcp_adapter *adapter,
99                                           int channel, unsigned int id,
100                                           unsigned int lun)
101 {
102         struct zfcp_port *port;
103         struct zfcp_unit *unit;
104         int scsi_lun;
105
106         list_for_each_entry(port, &adapter->port_list_head, list) {
107                 if (!port->rport || (id != port->rport->scsi_target_id))
108                         continue;
109                 list_for_each_entry(unit, &port->unit_list_head, list) {
110                         scsi_lun = scsilun_to_int(
111                                 (struct scsi_lun *)&unit->fcp_lun);
112                         if (lun == scsi_lun)
113                                 return unit;
114                 }
115         }
116
117         return NULL;
118 }
119
120 static int zfcp_scsi_slave_alloc(struct scsi_device *sdp)
121 {
122         struct zfcp_adapter *adapter;
123         struct zfcp_unit *unit;
124         unsigned long flags;
125         int retval = -ENXIO;
126
127         adapter = (struct zfcp_adapter *) sdp->host->hostdata[0];
128         if (!adapter)
129                 goto out;
130
131         read_lock_irqsave(&zfcp_data.config_lock, flags);
132         unit = zfcp_unit_lookup(adapter, sdp->channel, sdp->id, sdp->lun);
133         if (unit &&
134             (atomic_read(&unit->status) & ZFCP_STATUS_UNIT_REGISTERED)) {
135                 sdp->hostdata = unit;
136                 unit->device = sdp;
137                 zfcp_unit_get(unit);
138                 retval = 0;
139         }
140         read_unlock_irqrestore(&zfcp_data.config_lock, flags);
141 out:
142         return retval;
143 }
144
145 static int zfcp_scsi_eh_abort_handler(struct scsi_cmnd *scpnt)
146 {
147         struct Scsi_Host *scsi_host;
148         struct zfcp_adapter *adapter;
149         struct zfcp_unit *unit;
150         struct zfcp_fsf_req *fsf_req;
151         unsigned long flags;
152         unsigned long old_req_id = (unsigned long) scpnt->host_scribble;
153         int retval = SUCCESS;
154
155         scsi_host = scpnt->device->host;
156         adapter = (struct zfcp_adapter *) scsi_host->hostdata[0];
157         unit = scpnt->device->hostdata;
158
159         /* avoid race condition between late normal completion and abort */
160         write_lock_irqsave(&adapter->abort_lock, flags);
161
162         /* Check whether corresponding fsf_req is still pending */
163         spin_lock(&adapter->req_list_lock);
164         fsf_req = zfcp_reqlist_find(adapter, old_req_id);
165         spin_unlock(&adapter->req_list_lock);
166         if (!fsf_req) {
167                 write_unlock_irqrestore(&adapter->abort_lock, flags);
168                 zfcp_scsi_dbf_event_abort("lte1", adapter, scpnt, NULL, 0);
169                 return retval;
170         }
171         fsf_req->data = NULL;
172
173         /* don't access old fsf_req after releasing the abort_lock */
174         write_unlock_irqrestore(&adapter->abort_lock, flags);
175
176         fsf_req = zfcp_fsf_abort_fcp_command(old_req_id, adapter, unit, 0);
177         if (!fsf_req) {
178                 zfcp_scsi_dbf_event_abort("nres", adapter, scpnt, NULL,
179                                           old_req_id);
180                 retval = FAILED;
181                 return retval;
182         }
183
184         __wait_event(fsf_req->completion_wq,
185                      fsf_req->status & ZFCP_STATUS_FSFREQ_COMPLETED);
186
187         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ABORTSUCCEEDED) {
188                 zfcp_scsi_dbf_event_abort("okay", adapter, scpnt, fsf_req, 0);
189         } else if (fsf_req->status & ZFCP_STATUS_FSFREQ_ABORTNOTNEEDED) {
190                 zfcp_scsi_dbf_event_abort("lte2", adapter, scpnt, fsf_req, 0);
191         } else {
192                 zfcp_scsi_dbf_event_abort("fail", adapter, scpnt, fsf_req, 0);
193                 retval = FAILED;
194         }
195         zfcp_fsf_req_free(fsf_req);
196
197         return retval;
198 }
199
200 static int zfcp_task_mgmt_function(struct zfcp_unit *unit, u8 tm_flags,
201                                          struct scsi_cmnd *scpnt)
202 {
203         struct zfcp_adapter *adapter = unit->port->adapter;
204         struct zfcp_fsf_req *fsf_req;
205         int retval = SUCCESS;
206
207         /* issue task management function */
208         fsf_req = zfcp_fsf_send_fcp_ctm(adapter, unit, tm_flags, 0);
209         if (!fsf_req) {
210                 zfcp_scsi_dbf_event_devreset("nres", tm_flags, unit, scpnt);
211                 return FAILED;
212         }
213
214         __wait_event(fsf_req->completion_wq,
215                      fsf_req->status & ZFCP_STATUS_FSFREQ_COMPLETED);
216
217         /*
218          * check completion status of task management function
219          */
220         if (fsf_req->status & ZFCP_STATUS_FSFREQ_TMFUNCFAILED) {
221                 zfcp_scsi_dbf_event_devreset("fail", tm_flags, unit, scpnt);
222                 retval = FAILED;
223         } else if (fsf_req->status & ZFCP_STATUS_FSFREQ_TMFUNCNOTSUPP) {
224                 zfcp_scsi_dbf_event_devreset("nsup", tm_flags, unit, scpnt);
225                 retval = FAILED;
226         } else
227                 zfcp_scsi_dbf_event_devreset("okay", tm_flags, unit, scpnt);
228
229         zfcp_fsf_req_free(fsf_req);
230
231         return retval;
232 }
233
234 static int zfcp_scsi_eh_device_reset_handler(struct scsi_cmnd *scpnt)
235 {
236         struct zfcp_unit *unit = scpnt->device->hostdata;
237
238         if (!unit) {
239                 WARN_ON(1);
240                 return SUCCESS;
241         }
242         return zfcp_task_mgmt_function(unit, FCP_LOGICAL_UNIT_RESET, scpnt);
243 }
244
245 static int zfcp_scsi_eh_target_reset_handler(struct scsi_cmnd *scpnt)
246 {
247         struct zfcp_unit *unit = scpnt->device->hostdata;
248
249         if (!unit) {
250                 WARN_ON(1);
251                 return SUCCESS;
252         }
253         return zfcp_task_mgmt_function(unit, FCP_TARGET_RESET, scpnt);
254 }
255
256 static int zfcp_scsi_eh_host_reset_handler(struct scsi_cmnd *scpnt)
257 {
258         struct zfcp_unit *unit;
259         struct zfcp_adapter *adapter;
260
261         unit = scpnt->device->hostdata;
262         adapter = unit->port->adapter;
263         zfcp_erp_adapter_reopen(adapter, 0, 141, scpnt);
264         zfcp_erp_wait(adapter);
265
266         return SUCCESS;
267 }
268
269 int zfcp_adapter_scsi_register(struct zfcp_adapter *adapter)
270 {
271         struct ccw_dev_id dev_id;
272
273         if (adapter->scsi_host)
274                 return 0;
275
276         ccw_device_get_id(adapter->ccw_device, &dev_id);
277         /* register adapter as SCSI host with mid layer of SCSI stack */
278         adapter->scsi_host = scsi_host_alloc(&zfcp_data.scsi_host_template,
279                                              sizeof (struct zfcp_adapter *));
280         if (!adapter->scsi_host) {
281                 dev_err(&adapter->ccw_device->dev,
282                         "Registering the FCP device with the "
283                         "SCSI stack failed\n");
284                 return -EIO;
285         }
286
287         /* tell the SCSI stack some characteristics of this adapter */
288         adapter->scsi_host->max_id = 1;
289         adapter->scsi_host->max_lun = 1;
290         adapter->scsi_host->max_channel = 0;
291         adapter->scsi_host->unique_id = dev_id.devno;
292         adapter->scsi_host->max_cmd_len = 255;
293         adapter->scsi_host->transportt = zfcp_data.scsi_transport_template;
294
295         adapter->scsi_host->hostdata[0] = (unsigned long) adapter;
296
297         if (scsi_add_host(adapter->scsi_host, &adapter->ccw_device->dev)) {
298                 scsi_host_put(adapter->scsi_host);
299                 return -EIO;
300         }
301
302         return 0;
303 }
304
305 void zfcp_adapter_scsi_unregister(struct zfcp_adapter *adapter)
306 {
307         struct Scsi_Host *shost;
308         struct zfcp_port *port;
309
310         shost = adapter->scsi_host;
311         if (!shost)
312                 return;
313
314         read_lock_irq(&zfcp_data.config_lock);
315         list_for_each_entry(port, &adapter->port_list_head, list)
316                 if (port->rport)
317                         port->rport = NULL;
318
319         read_unlock_irq(&zfcp_data.config_lock);
320         fc_remove_host(shost);
321         scsi_remove_host(shost);
322         scsi_host_put(shost);
323         adapter->scsi_host = NULL;
324
325         return;
326 }
327
328 static struct fc_host_statistics*
329 zfcp_init_fc_host_stats(struct zfcp_adapter *adapter)
330 {
331         struct fc_host_statistics *fc_stats;
332
333         if (!adapter->fc_stats) {
334                 fc_stats = kmalloc(sizeof(*fc_stats), GFP_KERNEL);
335                 if (!fc_stats)
336                         return NULL;
337                 adapter->fc_stats = fc_stats; /* freed in adater_dequeue */
338         }
339         memset(adapter->fc_stats, 0, sizeof(*adapter->fc_stats));
340         return adapter->fc_stats;
341 }
342
343 static void zfcp_adjust_fc_host_stats(struct fc_host_statistics *fc_stats,
344                                       struct fsf_qtcb_bottom_port *data,
345                                       struct fsf_qtcb_bottom_port *old)
346 {
347         fc_stats->seconds_since_last_reset =
348                 data->seconds_since_last_reset - old->seconds_since_last_reset;
349         fc_stats->tx_frames = data->tx_frames - old->tx_frames;
350         fc_stats->tx_words = data->tx_words - old->tx_words;
351         fc_stats->rx_frames = data->rx_frames - old->rx_frames;
352         fc_stats->rx_words = data->rx_words - old->rx_words;
353         fc_stats->lip_count = data->lip - old->lip;
354         fc_stats->nos_count = data->nos - old->nos;
355         fc_stats->error_frames = data->error_frames - old->error_frames;
356         fc_stats->dumped_frames = data->dumped_frames - old->dumped_frames;
357         fc_stats->link_failure_count = data->link_failure - old->link_failure;
358         fc_stats->loss_of_sync_count = data->loss_of_sync - old->loss_of_sync;
359         fc_stats->loss_of_signal_count =
360                 data->loss_of_signal - old->loss_of_signal;
361         fc_stats->prim_seq_protocol_err_count =
362                 data->psp_error_counts - old->psp_error_counts;
363         fc_stats->invalid_tx_word_count =
364                 data->invalid_tx_words - old->invalid_tx_words;
365         fc_stats->invalid_crc_count = data->invalid_crcs - old->invalid_crcs;
366         fc_stats->fcp_input_requests =
367                 data->input_requests - old->input_requests;
368         fc_stats->fcp_output_requests =
369                 data->output_requests - old->output_requests;
370         fc_stats->fcp_control_requests =
371                 data->control_requests - old->control_requests;
372         fc_stats->fcp_input_megabytes = data->input_mb - old->input_mb;
373         fc_stats->fcp_output_megabytes = data->output_mb - old->output_mb;
374 }
375
376 static void zfcp_set_fc_host_stats(struct fc_host_statistics *fc_stats,
377                                    struct fsf_qtcb_bottom_port *data)
378 {
379         fc_stats->seconds_since_last_reset = data->seconds_since_last_reset;
380         fc_stats->tx_frames = data->tx_frames;
381         fc_stats->tx_words = data->tx_words;
382         fc_stats->rx_frames = data->rx_frames;
383         fc_stats->rx_words = data->rx_words;
384         fc_stats->lip_count = data->lip;
385         fc_stats->nos_count = data->nos;
386         fc_stats->error_frames = data->error_frames;
387         fc_stats->dumped_frames = data->dumped_frames;
388         fc_stats->link_failure_count = data->link_failure;
389         fc_stats->loss_of_sync_count = data->loss_of_sync;
390         fc_stats->loss_of_signal_count = data->loss_of_signal;
391         fc_stats->prim_seq_protocol_err_count = data->psp_error_counts;
392         fc_stats->invalid_tx_word_count = data->invalid_tx_words;
393         fc_stats->invalid_crc_count = data->invalid_crcs;
394         fc_stats->fcp_input_requests = data->input_requests;
395         fc_stats->fcp_output_requests = data->output_requests;
396         fc_stats->fcp_control_requests = data->control_requests;
397         fc_stats->fcp_input_megabytes = data->input_mb;
398         fc_stats->fcp_output_megabytes = data->output_mb;
399 }
400
401 static struct fc_host_statistics *zfcp_get_fc_host_stats(struct Scsi_Host *host)
402 {
403         struct zfcp_adapter *adapter;
404         struct fc_host_statistics *fc_stats;
405         struct fsf_qtcb_bottom_port *data;
406         int ret;
407
408         adapter = (struct zfcp_adapter *)host->hostdata[0];
409         fc_stats = zfcp_init_fc_host_stats(adapter);
410         if (!fc_stats)
411                 return NULL;
412
413         data = kzalloc(sizeof(*data), GFP_KERNEL);
414         if (!data)
415                 return NULL;
416
417         ret = zfcp_fsf_exchange_port_data_sync(adapter, data);
418         if (ret) {
419                 kfree(data);
420                 return NULL;
421         }
422
423         if (adapter->stats_reset &&
424             ((jiffies/HZ - adapter->stats_reset) <
425              data->seconds_since_last_reset))
426                 zfcp_adjust_fc_host_stats(fc_stats, data,
427                                           adapter->stats_reset_data);
428         else
429                 zfcp_set_fc_host_stats(fc_stats, data);
430
431         kfree(data);
432         return fc_stats;
433 }
434
435 static void zfcp_reset_fc_host_stats(struct Scsi_Host *shost)
436 {
437         struct zfcp_adapter *adapter;
438         struct fsf_qtcb_bottom_port *data;
439         int ret;
440
441         adapter = (struct zfcp_adapter *)shost->hostdata[0];
442         data = kzalloc(sizeof(*data), GFP_KERNEL);
443         if (!data)
444                 return;
445
446         ret = zfcp_fsf_exchange_port_data_sync(adapter, data);
447         if (ret)
448                 kfree(data);
449         else {
450                 adapter->stats_reset = jiffies/HZ;
451                 kfree(adapter->stats_reset_data);
452                 adapter->stats_reset_data = data; /* finally freed in
453                                                      adapter_dequeue */
454         }
455 }
456
457 static void zfcp_get_host_port_state(struct Scsi_Host *shost)
458 {
459         struct zfcp_adapter *adapter =
460                 (struct zfcp_adapter *)shost->hostdata[0];
461         int status = atomic_read(&adapter->status);
462
463         if ((status & ZFCP_STATUS_COMMON_RUNNING) &&
464             !(status & ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED))
465                 fc_host_port_state(shost) = FC_PORTSTATE_ONLINE;
466         else if (status & ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED)
467                 fc_host_port_state(shost) = FC_PORTSTATE_LINKDOWN;
468         else if (status & ZFCP_STATUS_COMMON_ERP_FAILED)
469                 fc_host_port_state(shost) = FC_PORTSTATE_ERROR;
470         else
471                 fc_host_port_state(shost) = FC_PORTSTATE_UNKNOWN;
472 }
473
474 static void zfcp_set_rport_dev_loss_tmo(struct fc_rport *rport, u32 timeout)
475 {
476         rport->dev_loss_tmo = timeout;
477 }
478
479 struct fc_function_template zfcp_transport_functions = {
480         .show_starget_port_id = 1,
481         .show_starget_port_name = 1,
482         .show_starget_node_name = 1,
483         .show_rport_supported_classes = 1,
484         .show_rport_maxframe_size = 1,
485         .show_rport_dev_loss_tmo = 1,
486         .show_host_node_name = 1,
487         .show_host_port_name = 1,
488         .show_host_permanent_port_name = 1,
489         .show_host_supported_classes = 1,
490         .show_host_supported_speeds = 1,
491         .show_host_maxframe_size = 1,
492         .show_host_serial_number = 1,
493         .get_fc_host_stats = zfcp_get_fc_host_stats,
494         .reset_fc_host_stats = zfcp_reset_fc_host_stats,
495         .set_rport_dev_loss_tmo = zfcp_set_rport_dev_loss_tmo,
496         .get_host_port_state = zfcp_get_host_port_state,
497         .show_host_port_state = 1,
498         /* no functions registered for following dynamic attributes but
499            directly set by LLDD */
500         .show_host_port_type = 1,
501         .show_host_speed = 1,
502         .show_host_port_id = 1,
503         .disable_target_scan = 1,
504 };
505
506 struct zfcp_data zfcp_data = {
507         .scsi_host_template = {
508                 .name                    = "zfcp",
509                 .module                  = THIS_MODULE,
510                 .proc_name               = "zfcp",
511                 .slave_alloc             = zfcp_scsi_slave_alloc,
512                 .slave_configure         = zfcp_scsi_slave_configure,
513                 .slave_destroy           = zfcp_scsi_slave_destroy,
514                 .queuecommand            = zfcp_scsi_queuecommand,
515                 .eh_abort_handler        = zfcp_scsi_eh_abort_handler,
516                 .eh_device_reset_handler = zfcp_scsi_eh_device_reset_handler,
517                 .eh_target_reset_handler = zfcp_scsi_eh_target_reset_handler,
518                 .eh_host_reset_handler   = zfcp_scsi_eh_host_reset_handler,
519                 .can_queue               = 4096,
520                 .this_id                 = -1,
521                 .sg_tablesize            = ZFCP_MAX_SBALES_PER_REQ,
522                 .cmd_per_lun             = 1,
523                 .use_clustering          = 1,
524                 .sdev_attrs              = zfcp_sysfs_sdev_attrs,
525                 .max_sectors             = (ZFCP_MAX_SBALES_PER_REQ * 8),
526                 .shost_attrs             = zfcp_sysfs_shost_attrs,
527         },
528 };