1 /*
2  * Aic94xx SAS/SATA Tasks
3  *
4  * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
5  * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
6  *
7  * This file is licensed under GPLv2.
8  *
9  * This file is part of the aic94xx driver.
10  *
11  * The aic94xx driver is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; version 2 of the
14  * License.
15  *
16  * The aic94xx driver is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with the aic94xx driver; if not, write to the Free Software
23  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
24  *
25  */
26 
27 #include <linux/spinlock.h>
28 #include "aic94xx.h"
29 #include "aic94xx_sas.h"
30 #include "aic94xx_hwi.h"
31 
32 static void asd_unbuild_ata_ascb(struct asd_ascb *a);
33 static void asd_unbuild_smp_ascb(struct asd_ascb *a);
34 static void asd_unbuild_ssp_ascb(struct asd_ascb *a);
35 
36 static void asd_can_dequeue(struct asd_ha_struct *asd_ha, int num)
37 {
38 	unsigned long flags;
39 
40 	spin_lock_irqsave(&asd_ha->seq.pend_q_lock, flags);
41 	asd_ha->seq.can_queue += num;
42 	spin_unlock_irqrestore(&asd_ha->seq.pend_q_lock, flags);
43 }
44 
45 /* PCI_DMA_... to our direction translation.
46  */
47 static const u8 data_dir_flags[] = {
48 	[PCI_DMA_BIDIRECTIONAL] = DATA_DIR_BYRECIPIENT,	/* UNSPECIFIED */
49 	[PCI_DMA_TODEVICE]      = DATA_DIR_OUT, /* OUTBOUND */
50 	[PCI_DMA_FROMDEVICE]    = DATA_DIR_IN, /* INBOUND */
51 	[PCI_DMA_NONE]          = DATA_DIR_NONE, /* NO TRANSFER */
52 };
53 
54 static int asd_map_scatterlist(struct sas_task *task,
55 			       struct sg_el *sg_arr,
56 			       gfp_t gfp_flags)
57 {
58 	struct asd_ascb *ascb = task->lldd_task;
59 	struct asd_ha_struct *asd_ha = ascb->ha;
60 	struct scatterlist *sc;
61 	int num_sg, res;
62 
63 	if (task->data_dir == PCI_DMA_NONE)
64 		return 0;
65 
66 	if (task->num_scatter == 0) {
67 		void *p = task->scatter;
68 		dma_addr_t dma = pci_map_single(asd_ha->pcidev, p,
69 						task->total_xfer_len,
70 						task->data_dir);
71 		sg_arr[0].bus_addr = cpu_to_le64((u64)dma);
72 		sg_arr[0].size = cpu_to_le32(task->total_xfer_len);
73 		sg_arr[0].flags |= ASD_SG_EL_LIST_EOL;
74 		return 0;
75 	}
76 
77 	/* STP tasks come from libata which has already mapped
78 	 * the SG list */
79 	if (sas_protocol_ata(task->task_proto))
80 		num_sg = task->num_scatter;
81 	else
82 		num_sg = pci_map_sg(asd_ha->pcidev, task->scatter,
83 				    task->num_scatter, task->data_dir);
84 	if (num_sg == 0)
85 		return -ENOMEM;
86 
87 	if (num_sg > 3) {
88 		int i;
89 
90 		ascb->sg_arr = asd_alloc_coherent(asd_ha,
91 						  num_sg*sizeof(struct sg_el),
92 						  gfp_flags);
93 		if (!ascb->sg_arr) {
94 			res = -ENOMEM;
95 			goto err_unmap;
96 		}
97 		for_each_sg(task->scatter, sc, num_sg, i) {
98 			struct sg_el *sg =
99 				&((struct sg_el *)ascb->sg_arr->vaddr)[i];
100 			sg->bus_addr = cpu_to_le64((u64)sg_dma_address(sc));
101 			sg->size = cpu_to_le32((u32)sg_dma_len(sc));
102 			if (i == num_sg-1)
103 				sg->flags |= ASD_SG_EL_LIST_EOL;
104 		}
105 
106 		for_each_sg(task->scatter, sc, 2, i) {
107 			sg_arr[i].bus_addr =
108 				cpu_to_le64((u64)sg_dma_address(sc));
109 			sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
110 		}
111 		sg_arr[1].next_sg_offs = 2 * sizeof(*sg_arr);
112 		sg_arr[1].flags |= ASD_SG_EL_LIST_EOS;
113 
114 		memset(&sg_arr[2], 0, sizeof(*sg_arr));
115 		sg_arr[2].bus_addr=cpu_to_le64((u64)ascb->sg_arr->dma_handle);
116 	} else {
117 		int i;
118 		for_each_sg(task->scatter, sc, num_sg, i) {
119 			sg_arr[i].bus_addr =
120 				cpu_to_le64((u64)sg_dma_address(sc));
121 			sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
122 		}
123 		sg_arr[i-1].flags |= ASD_SG_EL_LIST_EOL;
124 	}
125 
126 	return 0;
127 err_unmap:
128 	if (sas_protocol_ata(task->task_proto))
129 		pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
130 			     task->data_dir);
131 	return res;
132 }
133 
134 static void asd_unmap_scatterlist(struct asd_ascb *ascb)
135 {
136 	struct asd_ha_struct *asd_ha = ascb->ha;
137 	struct sas_task *task = ascb->uldd_task;
138 
139 	if (task->data_dir == PCI_DMA_NONE)
140 		return;
141 
142 	if (task->num_scatter == 0) {
143 		dma_addr_t dma = (dma_addr_t)
144 		       le64_to_cpu(ascb->scb->ssp_task.sg_element[0].bus_addr);
145 		pci_unmap_single(ascb->ha->pcidev, dma, task->total_xfer_len,
146 				 task->data_dir);
147 		return;
148 	}
149 
150 	asd_free_coherent(asd_ha, ascb->sg_arr);
151 	if (task->task_proto != SAS_PROTOCOL_STP)
152 		pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
153 			     task->data_dir);
154 }
155 
156 /* ---------- Task complete tasklet ---------- */
157 
158 static void asd_get_response_tasklet(struct asd_ascb *ascb,
159 				     struct done_list_struct *dl)
160 {
161 	struct asd_ha_struct *asd_ha = ascb->ha;
162 	struct sas_task *task = ascb->uldd_task;
163 	struct task_status_struct *ts = &task->task_status;
164 	unsigned long flags;
165 	struct tc_resp_sb_struct {
166 		__le16 index_escb;
167 		u8     len_lsb;
168 		u8     flags;
169 	} __attribute__ ((packed)) *resp_sb = (void *) dl->status_block;
170 
171 /* 	int  size   = ((resp_sb->flags & 7) << 8) | resp_sb->len_lsb; */
172 	int  edb_id = ((resp_sb->flags & 0x70) >> 4)-1;
173 	struct asd_ascb *escb;
174 	struct asd_dma_tok *edb;
175 	void *r;
176 
177 	spin_lock_irqsave(&asd_ha->seq.tc_index_lock, flags);
178 	escb = asd_tc_index_find(&asd_ha->seq,
179 				 (int)le16_to_cpu(resp_sb->index_escb));
180 	spin_unlock_irqrestore(&asd_ha->seq.tc_index_lock, flags);
181 
182 	if (!escb) {
183 		ASD_DPRINTK("Uh-oh! No escb for this dl?!\n");
184 		return;
185 	}
186 
187 	ts->buf_valid_size = 0;
188 	edb = asd_ha->seq.edb_arr[edb_id + escb->edb_index];
189 	r = edb->vaddr;
190 	if (task->task_proto == SAS_PROTOCOL_SSP) {
191 		struct ssp_response_iu *iu =
192 			r + 16 + sizeof(struct ssp_frame_hdr);
193 
194 		ts->residual = le32_to_cpu(*(__le32 *)r);
195 
196 		sas_ssp_task_response(&asd_ha->pcidev->dev, task, iu);
197 	}  else {
198 		struct ata_task_resp *resp = (void *) &ts->buf[0];
199 
200 		ts->residual = le32_to_cpu(*(__le32 *)r);
201 
202 		if (SAS_STATUS_BUF_SIZE >= sizeof(*resp)) {
203 			resp->frame_len = le16_to_cpu(*(__le16 *)(r+6));
204 			memcpy(&resp->ending_fis[0], r+16, ATA_RESP_FIS_SIZE);
205 			ts->buf_valid_size = sizeof(*resp);
206 		}
207 	}
208 
209 	asd_invalidate_edb(escb, edb_id);
210 }
211 
212 static void asd_task_tasklet_complete(struct asd_ascb *ascb,
213 				      struct done_list_struct *dl)
214 {
215 	struct sas_task *task = ascb->uldd_task;
216 	struct task_status_struct *ts = &task->task_status;
217 	unsigned long flags;
218 	u8 opcode = dl->opcode;
219 
220 	asd_can_dequeue(ascb->ha, 1);
221 
222 Again:
223 	switch (opcode) {
224 	case TC_NO_ERROR:
225 		ts->resp = SAS_TASK_COMPLETE;
226 		ts->stat = SAM_STAT_GOOD;
227 		break;
228 	case TC_UNDERRUN:
229 		ts->resp = SAS_TASK_COMPLETE;
230 		ts->stat = SAS_DATA_UNDERRUN;
231 		ts->residual = le32_to_cpu(*(__le32 *)dl->status_block);
232 		break;
233 	case TC_OVERRUN:
234 		ts->resp = SAS_TASK_COMPLETE;
235 		ts->stat = SAS_DATA_OVERRUN;
236 		ts->residual = 0;
237 		break;
238 	case TC_SSP_RESP:
239 	case TC_ATA_RESP:
240 		ts->resp = SAS_TASK_COMPLETE;
241 		ts->stat = SAS_PROTO_RESPONSE;
242 		asd_get_response_tasklet(ascb, dl);
243 		break;
244 	case TF_OPEN_REJECT:
245 		ts->resp = SAS_TASK_UNDELIVERED;
246 		ts->stat = SAS_OPEN_REJECT;
247 		if (dl->status_block[1] & 2)
248 			ts->open_rej_reason = 1 + dl->status_block[2];
249 		else if (dl->status_block[1] & 1)
250 			ts->open_rej_reason = (dl->status_block[2] >> 4)+10;
251 		else
252 			ts->open_rej_reason = SAS_OREJ_UNKNOWN;
253 		break;
254 	case TF_OPEN_TO:
255 		ts->resp = SAS_TASK_UNDELIVERED;
256 		ts->stat = SAS_OPEN_TO;
257 		break;
258 	case TF_PHY_DOWN:
259 	case TU_PHY_DOWN:
260 		ts->resp = SAS_TASK_UNDELIVERED;
261 		ts->stat = SAS_PHY_DOWN;
262 		break;
263 	case TI_PHY_DOWN:
264 		ts->resp = SAS_TASK_COMPLETE;
265 		ts->stat = SAS_PHY_DOWN;
266 		break;
267 	case TI_BREAK:
268 	case TI_PROTO_ERR:
269 	case TI_NAK:
270 	case TI_ACK_NAK_TO:
271 	case TF_SMP_XMIT_RCV_ERR:
272 	case TC_ATA_R_ERR_RECV:
273 		ts->resp = SAS_TASK_COMPLETE;
274 		ts->stat = SAS_INTERRUPTED;
275 		break;
276 	case TF_BREAK:
277 	case TU_BREAK:
278 	case TU_ACK_NAK_TO:
279 	case TF_SMPRSP_TO:
280 		ts->resp = SAS_TASK_UNDELIVERED;
281 		ts->stat = SAS_DEV_NO_RESPONSE;
282 		break;
283 	case TF_NAK_RECV:
284 		ts->resp = SAS_TASK_COMPLETE;
285 		ts->stat = SAS_NAK_R_ERR;
286 		break;
287 	case TA_I_T_NEXUS_LOSS:
288 		opcode = dl->status_block[0];
289 		goto Again;
290 		break;
291 	case TF_INV_CONN_HANDLE:
292 		ts->resp = SAS_TASK_UNDELIVERED;
293 		ts->stat = SAS_DEVICE_UNKNOWN;
294 		break;
295 	case TF_REQUESTED_N_PENDING:
296 		ts->resp = SAS_TASK_UNDELIVERED;
297 		ts->stat = SAS_PENDING;
298 		break;
299 	case TC_TASK_CLEARED:
300 	case TA_ON_REQ:
301 		ts->resp = SAS_TASK_COMPLETE;
302 		ts->stat = SAS_ABORTED_TASK;
303 		break;
304 
305 	case TF_NO_SMP_CONN:
306 	case TF_TMF_NO_CTX:
307 	case TF_TMF_NO_TAG:
308 	case TF_TMF_TAG_FREE:
309 	case TF_TMF_TASK_DONE:
310 	case TF_TMF_NO_CONN_HANDLE:
311 	case TF_IRTT_TO:
312 	case TF_IU_SHORT:
313 	case TF_DATA_OFFS_ERR:
314 		ts->resp = SAS_TASK_UNDELIVERED;
315 		ts->stat = SAS_DEV_NO_RESPONSE;
316 		break;
317 
318 	case TC_LINK_ADM_RESP:
319 	case TC_CONTROL_PHY:
320 	case TC_RESUME:
321 	case TC_PARTIAL_SG_LIST:
322 	default:
323 		ASD_DPRINTK("%s: dl opcode: 0x%x?\n", __func__, opcode);
324 		break;
325 	}
326 
327 	switch (task->task_proto) {
328 	case SAS_PROTOCOL_SATA:
329 	case SAS_PROTOCOL_STP:
330 		asd_unbuild_ata_ascb(ascb);
331 		break;
332 	case SAS_PROTOCOL_SMP:
333 		asd_unbuild_smp_ascb(ascb);
334 		break;
335 	case SAS_PROTOCOL_SSP:
336 		asd_unbuild_ssp_ascb(ascb);
337 	default:
338 		break;
339 	}
340 
341 	spin_lock_irqsave(&task->task_state_lock, flags);
342 	task->task_state_flags &= ~SAS_TASK_STATE_PENDING;
343 	task->task_state_flags &= ~SAS_TASK_AT_INITIATOR;
344 	task->task_state_flags |= SAS_TASK_STATE_DONE;
345 	if (unlikely((task->task_state_flags & SAS_TASK_STATE_ABORTED))) {
346 		struct completion *completion = ascb->completion;
347 		spin_unlock_irqrestore(&task->task_state_lock, flags);
348 		ASD_DPRINTK("task 0x%p done with opcode 0x%x resp 0x%x "
349 			    "stat 0x%x but aborted by upper layer!\n",
350 			    task, opcode, ts->resp, ts->stat);
351 		if (completion)
352 			complete(completion);
353 	} else {
354 		spin_unlock_irqrestore(&task->task_state_lock, flags);
355 		task->lldd_task = NULL;
356 		asd_ascb_free(ascb);
357 		mb();
358 		task->task_done(task);
359 	}
360 }
361 
362 /* ---------- ATA ---------- */
363 
364 static int asd_build_ata_ascb(struct asd_ascb *ascb, struct sas_task *task,
365 			      gfp_t gfp_flags)
366 {
367 	struct domain_device *dev = task->dev;
368 	struct scb *scb;
369 	u8     flags;
370 	int    res = 0;
371 
372 	scb = ascb->scb;
373 
374 	if (unlikely(task->ata_task.device_control_reg_update))
375 		scb->header.opcode = CONTROL_ATA_DEV;
376 	else if (dev->sata_dev.class == ATA_DEV_ATAPI)
377 		scb->header.opcode = INITIATE_ATAPI_TASK;
378 	else
379 		scb->header.opcode = INITIATE_ATA_TASK;
380 
381 	scb->ata_task.proto_conn_rate = (1 << 5); /* STP */
382 	if (dev->port->oob_mode == SAS_OOB_MODE)
383 		scb->ata_task.proto_conn_rate |= dev->linkrate;
384 
385 	scb->ata_task.total_xfer_len = cpu_to_le32(task->total_xfer_len);
386 	scb->ata_task.fis = task->ata_task.fis;
387 	if (likely(!task->ata_task.device_control_reg_update))
388 		scb->ata_task.fis.flags |= 0x80; /* C=1: update ATA cmd reg */
389 	scb->ata_task.fis.flags &= 0xF0; /* PM_PORT field shall be 0 */
390 	if (dev->sata_dev.class == ATA_DEV_ATAPI)
391 		memcpy(scb->ata_task.atapi_packet, task->ata_task.atapi_packet,
392 		       16);
393 	scb->ata_task.sister_scb = cpu_to_le16(0xFFFF);
394 	scb->ata_task.conn_handle = cpu_to_le16(
395 		(u16)(unsigned long)dev->lldd_dev);
396 
397 	if (likely(!task->ata_task.device_control_reg_update)) {
398 		flags = 0;
399 		if (task->ata_task.dma_xfer)
400 			flags |= DATA_XFER_MODE_DMA;
401 		if (task->ata_task.use_ncq &&
402 		    dev->sata_dev.class != ATA_DEV_ATAPI)
403 			flags |= ATA_Q_TYPE_NCQ;
404 		flags |= data_dir_flags[task->data_dir];
405 		scb->ata_task.ata_flags = flags;
406 
407 		scb->ata_task.retry_count = task->ata_task.retry_count;
408 
409 		flags = 0;
410 		if (task->ata_task.set_affil_pol)
411 			flags |= SET_AFFIL_POLICY;
412 		if (task->ata_task.stp_affil_pol)
413 			flags |= STP_AFFIL_POLICY;
414 		scb->ata_task.flags = flags;
415 	}
416 	ascb->tasklet_complete = asd_task_tasklet_complete;
417 
418 	if (likely(!task->ata_task.device_control_reg_update))
419 		res = asd_map_scatterlist(task, scb->ata_task.sg_element,
420 					  gfp_flags);
421 
422 	return res;
423 }
424 
425 static void asd_unbuild_ata_ascb(struct asd_ascb *a)
426 {
427 	asd_unmap_scatterlist(a);
428 }
429 
430 /* ---------- SMP ---------- */
431 
432 static int asd_build_smp_ascb(struct asd_ascb *ascb, struct sas_task *task,
433 			      gfp_t gfp_flags)
434 {
435 	struct asd_ha_struct *asd_ha = ascb->ha;
436 	struct domain_device *dev = task->dev;
437 	struct scb *scb;
438 
439 	pci_map_sg(asd_ha->pcidev, &task->smp_task.smp_req, 1,
440 		   PCI_DMA_TODEVICE);
441 	pci_map_sg(asd_ha->pcidev, &task->smp_task.smp_resp, 1,
442 		   PCI_DMA_FROMDEVICE);
443 
444 	scb = ascb->scb;
445 
446 	scb->header.opcode = INITIATE_SMP_TASK;
447 
448 	scb->smp_task.proto_conn_rate = dev->linkrate;
449 
450 	scb->smp_task.smp_req.bus_addr =
451 		cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_req));
452 	scb->smp_task.smp_req.size =
453 		cpu_to_le32((u32)sg_dma_len(&task->smp_task.smp_req)-4);
454 
455 	scb->smp_task.smp_resp.bus_addr =
456 		cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_resp));
457 	scb->smp_task.smp_resp.size =
458 		cpu_to_le32((u32)sg_dma_len(&task->smp_task.smp_resp)-4);
459 
460 	scb->smp_task.sister_scb = cpu_to_le16(0xFFFF);
461 	scb->smp_task.conn_handle = cpu_to_le16((u16)
462 						(unsigned long)dev->lldd_dev);
463 
464 	ascb->tasklet_complete = asd_task_tasklet_complete;
465 
466 	return 0;
467 }
468 
469 static void asd_unbuild_smp_ascb(struct asd_ascb *a)
470 {
471 	struct sas_task *task = a->uldd_task;
472 
473 	BUG_ON(!task);
474 	pci_unmap_sg(a->ha->pcidev, &task->smp_task.smp_req, 1,
475 		     PCI_DMA_TODEVICE);
476 	pci_unmap_sg(a->ha->pcidev, &task->smp_task.smp_resp, 1,
477 		     PCI_DMA_FROMDEVICE);
478 }
479 
480 /* ---------- SSP ---------- */
481 
482 static int asd_build_ssp_ascb(struct asd_ascb *ascb, struct sas_task *task,
483 			      gfp_t gfp_flags)
484 {
485 	struct domain_device *dev = task->dev;
486 	struct scb *scb;
487 	int    res = 0;
488 
489 	scb = ascb->scb;
490 
491 	scb->header.opcode = INITIATE_SSP_TASK;
492 
493 	scb->ssp_task.proto_conn_rate  = (1 << 4); /* SSP */
494 	scb->ssp_task.proto_conn_rate |= dev->linkrate;
495 	scb->ssp_task.total_xfer_len = cpu_to_le32(task->total_xfer_len);
496 	scb->ssp_task.ssp_frame.frame_type = SSP_DATA;
497 	memcpy(scb->ssp_task.ssp_frame.hashed_dest_addr, dev->hashed_sas_addr,
498 	       HASHED_SAS_ADDR_SIZE);
499 	memcpy(scb->ssp_task.ssp_frame.hashed_src_addr,
500 	       dev->port->ha->hashed_sas_addr, HASHED_SAS_ADDR_SIZE);
501 	scb->ssp_task.ssp_frame.tptt = cpu_to_be16(0xFFFF);
502 
503 	memcpy(scb->ssp_task.ssp_cmd.lun, task->ssp_task.LUN, 8);
504 	if (task->ssp_task.enable_first_burst)
505 		scb->ssp_task.ssp_cmd.efb_prio_attr |= EFB_MASK;
506 	scb->ssp_task.ssp_cmd.efb_prio_attr |= (task->ssp_task.task_prio << 3);
507 	scb->ssp_task.ssp_cmd.efb_prio_attr |= (task->ssp_task.task_attr & 7);
508 	memcpy(scb->ssp_task.ssp_cmd.cdb, task->ssp_task.cmd->cmnd,
509 	       task->ssp_task.cmd->cmd_len);
510 
511 	scb->ssp_task.sister_scb = cpu_to_le16(0xFFFF);
512 	scb->ssp_task.conn_handle = cpu_to_le16(
513 		(u16)(unsigned long)dev->lldd_dev);
514 	scb->ssp_task.data_dir = data_dir_flags[task->data_dir];
515 	scb->ssp_task.retry_count = scb->ssp_task.retry_count;
516 
517 	ascb->tasklet_complete = asd_task_tasklet_complete;
518 
519 	res = asd_map_scatterlist(task, scb->ssp_task.sg_element, gfp_flags);
520 
521 	return res;
522 }
523 
524 static void asd_unbuild_ssp_ascb(struct asd_ascb *a)
525 {
526 	asd_unmap_scatterlist(a);
527 }
528 
529 /* ---------- Execute Task ---------- */
530 
531 static int asd_can_queue(struct asd_ha_struct *asd_ha, int num)
532 {
533 	int res = 0;
534 	unsigned long flags;
535 
536 	spin_lock_irqsave(&asd_ha->seq.pend_q_lock, flags);
537 	if ((asd_ha->seq.can_queue - num) < 0)
538 		res = -SAS_QUEUE_FULL;
539 	else
540 		asd_ha->seq.can_queue -= num;
541 	spin_unlock_irqrestore(&asd_ha->seq.pend_q_lock, flags);
542 
543 	return res;
544 }
545 
546 int asd_execute_task(struct sas_task *task, gfp_t gfp_flags)
547 {
548 	int res = 0;
549 	LIST_HEAD(alist);
550 	struct sas_task *t = task;
551 	struct asd_ascb *ascb = NULL, *a;
552 	struct asd_ha_struct *asd_ha = task->dev->port->ha->lldd_ha;
553 	unsigned long flags;
554 
555 	res = asd_can_queue(asd_ha, 1);
556 	if (res)
557 		return res;
558 
559 	res = 1;
560 	ascb = asd_ascb_alloc_list(asd_ha, &res, gfp_flags);
561 	if (res) {
562 		res = -ENOMEM;
563 		goto out_err;
564 	}
565 
566 	__list_add(&alist, ascb->list.prev, &ascb->list);
567 	list_for_each_entry(a, &alist, list) {
568 		a->uldd_task = t;
569 		t->lldd_task = a;
570 		break;
571 	}
572 	list_for_each_entry(a, &alist, list) {
573 		t = a->uldd_task;
574 		a->uldd_timer = 1;
575 		if (t->task_proto & SAS_PROTOCOL_STP)
576 			t->task_proto = SAS_PROTOCOL_STP;
577 		switch (t->task_proto) {
578 		case SAS_PROTOCOL_SATA:
579 		case SAS_PROTOCOL_STP:
580 			res = asd_build_ata_ascb(a, t, gfp_flags);
581 			break;
582 		case SAS_PROTOCOL_SMP:
583 			res = asd_build_smp_ascb(a, t, gfp_flags);
584 			break;
585 		case SAS_PROTOCOL_SSP:
586 			res = asd_build_ssp_ascb(a, t, gfp_flags);
587 			break;
588 		default:
589 			asd_printk("unknown sas_task proto: 0x%x\n",
590 				   t->task_proto);
591 			res = -ENOMEM;
592 			break;
593 		}
594 		if (res)
595 			goto out_err_unmap;
596 
597 		spin_lock_irqsave(&t->task_state_lock, flags);
598 		t->task_state_flags |= SAS_TASK_AT_INITIATOR;
599 		spin_unlock_irqrestore(&t->task_state_lock, flags);
600 	}
601 	list_del_init(&alist);
602 
603 	res = asd_post_ascb_list(asd_ha, ascb, 1);
604 	if (unlikely(res)) {
605 		a = NULL;
606 		__list_add(&alist, ascb->list.prev, &ascb->list);
607 		goto out_err_unmap;
608 	}
609 
610 	return 0;
611 out_err_unmap:
612 	{
613 		struct asd_ascb *b = a;
614 		list_for_each_entry(a, &alist, list) {
615 			if (a == b)
616 				break;
617 			t = a->uldd_task;
618 			spin_lock_irqsave(&t->task_state_lock, flags);
619 			t->task_state_flags &= ~SAS_TASK_AT_INITIATOR;
620 			spin_unlock_irqrestore(&t->task_state_lock, flags);
621 			switch (t->task_proto) {
622 			case SAS_PROTOCOL_SATA:
623 			case SAS_PROTOCOL_STP:
624 				asd_unbuild_ata_ascb(a);
625 				break;
626 			case SAS_PROTOCOL_SMP:
627 				asd_unbuild_smp_ascb(a);
628 				break;
629 			case SAS_PROTOCOL_SSP:
630 				asd_unbuild_ssp_ascb(a);
631 			default:
632 				break;
633 			}
634 			t->lldd_task = NULL;
635 		}
636 	}
637 	list_del_init(&alist);
638 out_err:
639 	if (ascb)
640 		asd_ascb_free_list(ascb);
641 	asd_can_dequeue(asd_ha, 1);
642 	return res;
643 }
644