Merge tag 's390-6.6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
[linux-2.6-microblaze.git] / drivers / scsi / aic94xx / aic94xx_task.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Aic94xx SAS/SATA Tasks
4  *
5  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
6  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
7  */
8
9 #include <linux/spinlock.h>
10 #include "aic94xx.h"
11 #include "aic94xx_sas.h"
12 #include "aic94xx_hwi.h"
13
14 static void asd_unbuild_ata_ascb(struct asd_ascb *a);
15 static void asd_unbuild_smp_ascb(struct asd_ascb *a);
16 static void asd_unbuild_ssp_ascb(struct asd_ascb *a);
17
18 static void asd_can_dequeue(struct asd_ha_struct *asd_ha, int num)
19 {
20         unsigned long flags;
21
22         spin_lock_irqsave(&asd_ha->seq.pend_q_lock, flags);
23         asd_ha->seq.can_queue += num;
24         spin_unlock_irqrestore(&asd_ha->seq.pend_q_lock, flags);
25 }
26
27 /* DMA_... to our direction translation.
28  */
29 static const u8 data_dir_flags[] = {
30         [DMA_BIDIRECTIONAL]     = DATA_DIR_BYRECIPIENT, /* UNSPECIFIED */
31         [DMA_TO_DEVICE]         = DATA_DIR_OUT,         /* OUTBOUND */
32         [DMA_FROM_DEVICE]       = DATA_DIR_IN,          /* INBOUND */
33         [DMA_NONE]              = DATA_DIR_NONE,        /* NO TRANSFER */
34 };
35
36 static int asd_map_scatterlist(struct sas_task *task,
37                                struct sg_el *sg_arr,
38                                gfp_t gfp_flags)
39 {
40         struct asd_ascb *ascb = task->lldd_task;
41         struct asd_ha_struct *asd_ha = ascb->ha;
42         struct scatterlist *sc;
43         int num_sg, res;
44
45         if (task->data_dir == DMA_NONE)
46                 return 0;
47
48         if (task->num_scatter == 0) {
49                 void *p = task->scatter;
50                 dma_addr_t dma = dma_map_single(&asd_ha->pcidev->dev, p,
51                                                 task->total_xfer_len,
52                                                 task->data_dir);
53                 if (dma_mapping_error(&asd_ha->pcidev->dev, dma))
54                         return -ENOMEM;
55
56                 sg_arr[0].bus_addr = cpu_to_le64((u64)dma);
57                 sg_arr[0].size = cpu_to_le32(task->total_xfer_len);
58                 sg_arr[0].flags |= ASD_SG_EL_LIST_EOL;
59                 return 0;
60         }
61
62         /* STP tasks come from libata which has already mapped
63          * the SG list */
64         if (sas_protocol_ata(task->task_proto))
65                 num_sg = task->num_scatter;
66         else
67                 num_sg = dma_map_sg(&asd_ha->pcidev->dev, task->scatter,
68                                     task->num_scatter, task->data_dir);
69         if (num_sg == 0)
70                 return -ENOMEM;
71
72         if (num_sg > 3) {
73                 int i;
74
75                 ascb->sg_arr = asd_alloc_coherent(asd_ha,
76                                                   num_sg*sizeof(struct sg_el),
77                                                   gfp_flags);
78                 if (!ascb->sg_arr) {
79                         res = -ENOMEM;
80                         goto err_unmap;
81                 }
82                 for_each_sg(task->scatter, sc, num_sg, i) {
83                         struct sg_el *sg =
84                                 &((struct sg_el *)ascb->sg_arr->vaddr)[i];
85                         sg->bus_addr = cpu_to_le64((u64)sg_dma_address(sc));
86                         sg->size = cpu_to_le32((u32)sg_dma_len(sc));
87                         if (i == num_sg-1)
88                                 sg->flags |= ASD_SG_EL_LIST_EOL;
89                 }
90
91                 for_each_sg(task->scatter, sc, 2, i) {
92                         sg_arr[i].bus_addr =
93                                 cpu_to_le64((u64)sg_dma_address(sc));
94                         sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
95                 }
96                 sg_arr[1].next_sg_offs = 2 * sizeof(*sg_arr);
97                 sg_arr[1].flags |= ASD_SG_EL_LIST_EOS;
98
99                 memset(&sg_arr[2], 0, sizeof(*sg_arr));
100                 sg_arr[2].bus_addr=cpu_to_le64((u64)ascb->sg_arr->dma_handle);
101         } else {
102                 int i;
103                 for_each_sg(task->scatter, sc, num_sg, i) {
104                         sg_arr[i].bus_addr =
105                                 cpu_to_le64((u64)sg_dma_address(sc));
106                         sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
107                 }
108                 sg_arr[i-1].flags |= ASD_SG_EL_LIST_EOL;
109         }
110
111         return 0;
112 err_unmap:
113         if (sas_protocol_ata(task->task_proto))
114                 dma_unmap_sg(&asd_ha->pcidev->dev, task->scatter,
115                              task->num_scatter, task->data_dir);
116         return res;
117 }
118
119 static void asd_unmap_scatterlist(struct asd_ascb *ascb)
120 {
121         struct asd_ha_struct *asd_ha = ascb->ha;
122         struct sas_task *task = ascb->uldd_task;
123
124         if (task->data_dir == DMA_NONE)
125                 return;
126
127         if (task->num_scatter == 0) {
128                 dma_addr_t dma = (dma_addr_t)
129                        le64_to_cpu(ascb->scb->ssp_task.sg_element[0].bus_addr);
130                 dma_unmap_single(&ascb->ha->pcidev->dev, dma,
131                                  task->total_xfer_len, task->data_dir);
132                 return;
133         }
134
135         asd_free_coherent(asd_ha, ascb->sg_arr);
136         if (task->task_proto != SAS_PROTOCOL_STP)
137                 dma_unmap_sg(&asd_ha->pcidev->dev, task->scatter,
138                              task->num_scatter, task->data_dir);
139 }
140
141 /* ---------- Task complete tasklet ---------- */
142
143 static void asd_get_response_tasklet(struct asd_ascb *ascb,
144                                      struct done_list_struct *dl)
145 {
146         struct asd_ha_struct *asd_ha = ascb->ha;
147         struct sas_task *task = ascb->uldd_task;
148         struct task_status_struct *ts = &task->task_status;
149         unsigned long flags;
150         struct tc_resp_sb_struct {
151                 __le16 index_escb;
152                 u8     len_lsb;
153                 u8     flags;
154         } __attribute__ ((packed)) *resp_sb = (void *) dl->status_block;
155
156 /*      int  size   = ((resp_sb->flags & 7) << 8) | resp_sb->len_lsb; */
157         int  edb_id = ((resp_sb->flags & 0x70) >> 4)-1;
158         struct asd_ascb *escb;
159         struct asd_dma_tok *edb;
160         void *r;
161
162         spin_lock_irqsave(&asd_ha->seq.tc_index_lock, flags);
163         escb = asd_tc_index_find(&asd_ha->seq,
164                                  (int)le16_to_cpu(resp_sb->index_escb));
165         spin_unlock_irqrestore(&asd_ha->seq.tc_index_lock, flags);
166
167         if (!escb) {
168                 ASD_DPRINTK("Uh-oh! No escb for this dl?!\n");
169                 return;
170         }
171
172         ts->buf_valid_size = 0;
173         edb = asd_ha->seq.edb_arr[edb_id + escb->edb_index];
174         r = edb->vaddr;
175         if (task->task_proto == SAS_PROTOCOL_SSP) {
176                 struct ssp_response_iu *iu =
177                         r + 16 + sizeof(struct ssp_frame_hdr);
178
179                 ts->residual = le32_to_cpu(*(__le32 *)r);
180
181                 sas_ssp_task_response(&asd_ha->pcidev->dev, task, iu);
182         }  else {
183                 struct ata_task_resp *resp = (void *) &ts->buf[0];
184
185                 ts->residual = le32_to_cpu(*(__le32 *)r);
186
187                 if (SAS_STATUS_BUF_SIZE >= sizeof(*resp)) {
188                         resp->frame_len = le16_to_cpu(*(__le16 *)(r+6));
189                         memcpy(&resp->ending_fis[0], r+16, ATA_RESP_FIS_SIZE);
190                         ts->buf_valid_size = sizeof(*resp);
191                 }
192         }
193
194         asd_invalidate_edb(escb, edb_id);
195 }
196
197 static void asd_task_tasklet_complete(struct asd_ascb *ascb,
198                                       struct done_list_struct *dl)
199 {
200         struct sas_task *task = ascb->uldd_task;
201         struct task_status_struct *ts = &task->task_status;
202         unsigned long flags;
203         u8 opcode = dl->opcode;
204
205         asd_can_dequeue(ascb->ha, 1);
206
207 Again:
208         switch (opcode) {
209         case TC_NO_ERROR:
210                 ts->resp = SAS_TASK_COMPLETE;
211                 ts->stat = SAS_SAM_STAT_GOOD;
212                 break;
213         case TC_UNDERRUN:
214                 ts->resp = SAS_TASK_COMPLETE;
215                 ts->stat = SAS_DATA_UNDERRUN;
216                 ts->residual = le32_to_cpu(*(__le32 *)dl->status_block);
217                 break;
218         case TC_OVERRUN:
219                 ts->resp = SAS_TASK_COMPLETE;
220                 ts->stat = SAS_DATA_OVERRUN;
221                 ts->residual = 0;
222                 break;
223         case TC_SSP_RESP:
224         case TC_ATA_RESP:
225                 ts->resp = SAS_TASK_COMPLETE;
226                 ts->stat = SAS_PROTO_RESPONSE;
227                 asd_get_response_tasklet(ascb, dl);
228                 break;
229         case TF_OPEN_REJECT:
230                 ts->resp = SAS_TASK_UNDELIVERED;
231                 ts->stat = SAS_OPEN_REJECT;
232                 if (dl->status_block[1] & 2)
233                         ts->open_rej_reason = 1 + dl->status_block[2];
234                 else if (dl->status_block[1] & 1)
235                         ts->open_rej_reason = (dl->status_block[2] >> 4)+10;
236                 else
237                         ts->open_rej_reason = SAS_OREJ_UNKNOWN;
238                 break;
239         case TF_OPEN_TO:
240                 ts->resp = SAS_TASK_UNDELIVERED;
241                 ts->stat = SAS_OPEN_TO;
242                 break;
243         case TF_PHY_DOWN:
244         case TU_PHY_DOWN:
245                 ts->resp = SAS_TASK_UNDELIVERED;
246                 ts->stat = SAS_PHY_DOWN;
247                 break;
248         case TI_PHY_DOWN:
249                 ts->resp = SAS_TASK_COMPLETE;
250                 ts->stat = SAS_PHY_DOWN;
251                 break;
252         case TI_BREAK:
253         case TI_PROTO_ERR:
254         case TI_NAK:
255         case TI_ACK_NAK_TO:
256         case TF_SMP_XMIT_RCV_ERR:
257         case TC_ATA_R_ERR_RECV:
258                 ts->resp = SAS_TASK_COMPLETE;
259                 ts->stat = SAS_INTERRUPTED;
260                 break;
261         case TF_BREAK:
262         case TU_BREAK:
263         case TU_ACK_NAK_TO:
264         case TF_SMPRSP_TO:
265                 ts->resp = SAS_TASK_UNDELIVERED;
266                 ts->stat = SAS_DEV_NO_RESPONSE;
267                 break;
268         case TF_NAK_RECV:
269                 ts->resp = SAS_TASK_COMPLETE;
270                 ts->stat = SAS_NAK_R_ERR;
271                 break;
272         case TA_I_T_NEXUS_LOSS:
273                 opcode = dl->status_block[0];
274                 goto Again;
275         case TF_INV_CONN_HANDLE:
276                 ts->resp = SAS_TASK_UNDELIVERED;
277                 ts->stat = SAS_DEVICE_UNKNOWN;
278                 break;
279         case TF_REQUESTED_N_PENDING:
280                 ts->resp = SAS_TASK_UNDELIVERED;
281                 ts->stat = SAS_PENDING;
282                 break;
283         case TC_TASK_CLEARED:
284         case TA_ON_REQ:
285                 ts->resp = SAS_TASK_COMPLETE;
286                 ts->stat = SAS_ABORTED_TASK;
287                 break;
288
289         case TF_NO_SMP_CONN:
290         case TF_TMF_NO_CTX:
291         case TF_TMF_NO_TAG:
292         case TF_TMF_TAG_FREE:
293         case TF_TMF_TASK_DONE:
294         case TF_TMF_NO_CONN_HANDLE:
295         case TF_IRTT_TO:
296         case TF_IU_SHORT:
297         case TF_DATA_OFFS_ERR:
298                 ts->resp = SAS_TASK_UNDELIVERED;
299                 ts->stat = SAS_DEV_NO_RESPONSE;
300                 break;
301
302         case TC_LINK_ADM_RESP:
303         case TC_CONTROL_PHY:
304         case TC_RESUME:
305         case TC_PARTIAL_SG_LIST:
306         default:
307                 ASD_DPRINTK("%s: dl opcode: 0x%x?\n", __func__, opcode);
308                 break;
309         }
310
311         switch (task->task_proto) {
312         case SAS_PROTOCOL_SATA:
313         case SAS_PROTOCOL_STP:
314                 asd_unbuild_ata_ascb(ascb);
315                 break;
316         case SAS_PROTOCOL_SMP:
317                 asd_unbuild_smp_ascb(ascb);
318                 break;
319         case SAS_PROTOCOL_SSP:
320                 asd_unbuild_ssp_ascb(ascb);
321                 break;
322         default:
323                 break;
324         }
325
326         spin_lock_irqsave(&task->task_state_lock, flags);
327         task->task_state_flags &= ~SAS_TASK_STATE_PENDING;
328         task->task_state_flags |= SAS_TASK_STATE_DONE;
329         if (unlikely((task->task_state_flags & SAS_TASK_STATE_ABORTED))) {
330                 struct completion *completion = ascb->completion;
331                 spin_unlock_irqrestore(&task->task_state_lock, flags);
332                 ASD_DPRINTK("task 0x%p done with opcode 0x%x resp 0x%x "
333                             "stat 0x%x but aborted by upper layer!\n",
334                             task, opcode, ts->resp, ts->stat);
335                 if (completion)
336                         complete(completion);
337         } else {
338                 spin_unlock_irqrestore(&task->task_state_lock, flags);
339                 task->lldd_task = NULL;
340                 asd_ascb_free(ascb);
341                 mb();
342                 task->task_done(task);
343         }
344 }
345
346 /* ---------- ATA ---------- */
347
348 static int asd_build_ata_ascb(struct asd_ascb *ascb, struct sas_task *task,
349                               gfp_t gfp_flags)
350 {
351         struct domain_device *dev = task->dev;
352         struct scb *scb;
353         u8     flags;
354         int    res = 0;
355
356         scb = ascb->scb;
357
358         if (unlikely(task->ata_task.device_control_reg_update))
359                 scb->header.opcode = CONTROL_ATA_DEV;
360         else if (dev->sata_dev.class == ATA_DEV_ATAPI)
361                 scb->header.opcode = INITIATE_ATAPI_TASK;
362         else
363                 scb->header.opcode = INITIATE_ATA_TASK;
364
365         scb->ata_task.proto_conn_rate = (1 << 5); /* STP */
366         if (dev->port->oob_mode == SAS_OOB_MODE)
367                 scb->ata_task.proto_conn_rate |= dev->linkrate;
368
369         scb->ata_task.total_xfer_len = cpu_to_le32(task->total_xfer_len);
370         scb->ata_task.fis = task->ata_task.fis;
371         if (likely(!task->ata_task.device_control_reg_update))
372                 scb->ata_task.fis.flags |= 0x80; /* C=1: update ATA cmd reg */
373         scb->ata_task.fis.flags &= 0xF0; /* PM_PORT field shall be 0 */
374         if (dev->sata_dev.class == ATA_DEV_ATAPI)
375                 memcpy(scb->ata_task.atapi_packet, task->ata_task.atapi_packet,
376                        16);
377         scb->ata_task.sister_scb = cpu_to_le16(0xFFFF);
378         scb->ata_task.conn_handle = cpu_to_le16(
379                 (u16)(unsigned long)dev->lldd_dev);
380
381         if (likely(!task->ata_task.device_control_reg_update)) {
382                 flags = 0;
383                 if (task->ata_task.dma_xfer)
384                         flags |= DATA_XFER_MODE_DMA;
385                 if (task->ata_task.use_ncq &&
386                     dev->sata_dev.class != ATA_DEV_ATAPI)
387                         flags |= ATA_Q_TYPE_NCQ;
388                 flags |= data_dir_flags[task->data_dir];
389                 scb->ata_task.ata_flags = flags;
390
391                 scb->ata_task.retry_count = 0;
392
393                 scb->ata_task.flags = 0;
394         }
395         ascb->tasklet_complete = asd_task_tasklet_complete;
396
397         if (likely(!task->ata_task.device_control_reg_update))
398                 res = asd_map_scatterlist(task, scb->ata_task.sg_element,
399                                           gfp_flags);
400
401         return res;
402 }
403
404 static void asd_unbuild_ata_ascb(struct asd_ascb *a)
405 {
406         asd_unmap_scatterlist(a);
407 }
408
409 /* ---------- SMP ---------- */
410
411 static int asd_build_smp_ascb(struct asd_ascb *ascb, struct sas_task *task,
412                               gfp_t gfp_flags)
413 {
414         struct asd_ha_struct *asd_ha = ascb->ha;
415         struct domain_device *dev = task->dev;
416         struct scb *scb;
417
418         dma_map_sg(&asd_ha->pcidev->dev, &task->smp_task.smp_req, 1,
419                    DMA_TO_DEVICE);
420         dma_map_sg(&asd_ha->pcidev->dev, &task->smp_task.smp_resp, 1,
421                    DMA_FROM_DEVICE);
422
423         scb = ascb->scb;
424
425         scb->header.opcode = INITIATE_SMP_TASK;
426
427         scb->smp_task.proto_conn_rate = dev->linkrate;
428
429         scb->smp_task.smp_req.bus_addr =
430                 cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_req));
431         scb->smp_task.smp_req.size =
432                 cpu_to_le32((u32)sg_dma_len(&task->smp_task.smp_req)-4);
433
434         scb->smp_task.smp_resp.bus_addr =
435                 cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_resp));
436         scb->smp_task.smp_resp.size =
437                 cpu_to_le32((u32)sg_dma_len(&task->smp_task.smp_resp)-4);
438
439         scb->smp_task.sister_scb = cpu_to_le16(0xFFFF);
440         scb->smp_task.conn_handle = cpu_to_le16((u16)
441                                                 (unsigned long)dev->lldd_dev);
442
443         ascb->tasklet_complete = asd_task_tasklet_complete;
444
445         return 0;
446 }
447
448 static void asd_unbuild_smp_ascb(struct asd_ascb *a)
449 {
450         struct sas_task *task = a->uldd_task;
451
452         BUG_ON(!task);
453         dma_unmap_sg(&a->ha->pcidev->dev, &task->smp_task.smp_req, 1,
454                      DMA_TO_DEVICE);
455         dma_unmap_sg(&a->ha->pcidev->dev, &task->smp_task.smp_resp, 1,
456                      DMA_FROM_DEVICE);
457 }
458
459 /* ---------- SSP ---------- */
460
461 static int asd_build_ssp_ascb(struct asd_ascb *ascb, struct sas_task *task,
462                               gfp_t gfp_flags)
463 {
464         struct domain_device *dev = task->dev;
465         struct scb *scb;
466         int    res = 0;
467
468         scb = ascb->scb;
469
470         scb->header.opcode = INITIATE_SSP_TASK;
471
472         scb->ssp_task.proto_conn_rate  = (1 << 4); /* SSP */
473         scb->ssp_task.proto_conn_rate |= dev->linkrate;
474         scb->ssp_task.total_xfer_len = cpu_to_le32(task->total_xfer_len);
475         scb->ssp_task.ssp_frame.frame_type = SSP_DATA;
476         memcpy(scb->ssp_task.ssp_frame.hashed_dest_addr, dev->hashed_sas_addr,
477                HASHED_SAS_ADDR_SIZE);
478         memcpy(scb->ssp_task.ssp_frame.hashed_src_addr,
479                dev->port->ha->hashed_sas_addr, HASHED_SAS_ADDR_SIZE);
480         scb->ssp_task.ssp_frame.tptt = cpu_to_be16(0xFFFF);
481
482         memcpy(scb->ssp_task.ssp_cmd.lun, task->ssp_task.LUN, 8);
483         scb->ssp_task.ssp_cmd.efb_prio_attr |= (task->ssp_task.task_attr & 7);
484         memcpy(scb->ssp_task.ssp_cmd.cdb, task->ssp_task.cmd->cmnd,
485                task->ssp_task.cmd->cmd_len);
486
487         scb->ssp_task.sister_scb = cpu_to_le16(0xFFFF);
488         scb->ssp_task.conn_handle = cpu_to_le16(
489                 (u16)(unsigned long)dev->lldd_dev);
490         scb->ssp_task.data_dir = data_dir_flags[task->data_dir];
491         scb->ssp_task.retry_count = scb->ssp_task.retry_count;
492
493         ascb->tasklet_complete = asd_task_tasklet_complete;
494
495         res = asd_map_scatterlist(task, scb->ssp_task.sg_element, gfp_flags);
496
497         return res;
498 }
499
500 static void asd_unbuild_ssp_ascb(struct asd_ascb *a)
501 {
502         asd_unmap_scatterlist(a);
503 }
504
505 /* ---------- Execute Task ---------- */
506
507 static int asd_can_queue(struct asd_ha_struct *asd_ha, int num)
508 {
509         int res = 0;
510         unsigned long flags;
511
512         spin_lock_irqsave(&asd_ha->seq.pend_q_lock, flags);
513         if ((asd_ha->seq.can_queue - num) < 0)
514                 res = -SAS_QUEUE_FULL;
515         else
516                 asd_ha->seq.can_queue -= num;
517         spin_unlock_irqrestore(&asd_ha->seq.pend_q_lock, flags);
518
519         return res;
520 }
521
522 int asd_execute_task(struct sas_task *task, gfp_t gfp_flags)
523 {
524         int res = 0;
525         LIST_HEAD(alist);
526         struct sas_task *t = task;
527         struct asd_ascb *ascb = NULL, *a;
528         struct asd_ha_struct *asd_ha = task->dev->port->ha->lldd_ha;
529
530         res = asd_can_queue(asd_ha, 1);
531         if (res)
532                 return res;
533
534         res = 1;
535         ascb = asd_ascb_alloc_list(asd_ha, &res, gfp_flags);
536         if (res) {
537                 res = -ENOMEM;
538                 goto out_err;
539         }
540
541         __list_add(&alist, ascb->list.prev, &ascb->list);
542         list_for_each_entry(a, &alist, list) {
543                 a->uldd_task = t;
544                 t->lldd_task = a;
545                 break;
546         }
547         list_for_each_entry(a, &alist, list) {
548                 t = a->uldd_task;
549                 a->uldd_timer = 1;
550                 if (t->task_proto & SAS_PROTOCOL_STP)
551                         t->task_proto = SAS_PROTOCOL_STP;
552                 switch (t->task_proto) {
553                 case SAS_PROTOCOL_SATA:
554                 case SAS_PROTOCOL_STP:
555                         res = asd_build_ata_ascb(a, t, gfp_flags);
556                         break;
557                 case SAS_PROTOCOL_SMP:
558                         res = asd_build_smp_ascb(a, t, gfp_flags);
559                         break;
560                 case SAS_PROTOCOL_SSP:
561                         res = asd_build_ssp_ascb(a, t, gfp_flags);
562                         break;
563                 default:
564                         asd_printk("unknown sas_task proto: 0x%x\n",
565                                    t->task_proto);
566                         res = -ENOMEM;
567                         break;
568                 }
569                 if (res)
570                         goto out_err_unmap;
571         }
572         list_del_init(&alist);
573
574         res = asd_post_ascb_list(asd_ha, ascb, 1);
575         if (unlikely(res)) {
576                 a = NULL;
577                 __list_add(&alist, ascb->list.prev, &ascb->list);
578                 goto out_err_unmap;
579         }
580
581         return 0;
582 out_err_unmap:
583         {
584                 struct asd_ascb *b = a;
585                 list_for_each_entry(a, &alist, list) {
586                         if (a == b)
587                                 break;
588                         t = a->uldd_task;
589                         switch (t->task_proto) {
590                         case SAS_PROTOCOL_SATA:
591                         case SAS_PROTOCOL_STP:
592                                 asd_unbuild_ata_ascb(a);
593                                 break;
594                         case SAS_PROTOCOL_SMP:
595                                 asd_unbuild_smp_ascb(a);
596                                 break;
597                         case SAS_PROTOCOL_SSP:
598                                 asd_unbuild_ssp_ascb(a);
599                                 break;
600                         default:
601                                 break;
602                         }
603                         t->lldd_task = NULL;
604                 }
605         }
606         list_del_init(&alist);
607 out_err:
608         if (ascb)
609                 asd_ascb_free_list(ascb);
610         asd_can_dequeue(asd_ha, 1);
611         return res;
612 }