aic94xx: aic94xx_task.c Implements the Execute Task SCSI RPC

diff -X linux-2.6.13/Documentation/dontdiff -Naur linux-2.6.13-orig/drivers/scsi/aic94xx/aic94xx_task.c linux-2.6.13/drivers/scsi/aic94xx/aic94xx_task.c
@@ -0,0 +1,645 @@
+/*
+ * Aic94xx SAS/SATA Tasks
+ *
+ * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
+ * Copyright (C) 2005 Luben Tuikov <[email protected]>
+ *
+ * This file is licensed under GPLv2.
+ * 
+ * This file is part of the aic94xx driver.
+ *
+ * The aic94xx driver is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of the
+ * License.
+ *
+ * The aic94xx driver is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the aic94xx driver; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * $Id: //depot/aic94xx/aic94xx_task.c#50 $
+ */
+
+#include <linux/spinlock.h>
+#include <scsi/sas/sas_task.h>
+#include <scsi/sas/sas_frames.h>
+#include "aic94xx.h"
+#include "aic94xx_sas.h"
+#include "aic94xx_hwi.h"
+
+static void asd_unbuild_ata_ascb(struct asd_ascb *a);
+static void asd_unbuild_smp_ascb(struct asd_ascb *a);
+static void asd_unbuild_ssp_ascb(struct asd_ascb *a);
+
+static inline void asd_can_dequeue(struct asd_ha_struct *asd_ha, int num)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&asd_ha->seq.pend_q_lock, flags);
+	asd_ha->seq.can_queue += num;
+	spin_unlock_irqrestore(&asd_ha->seq.pend_q_lock, flags);
+}
+
+/* PCI_DMA_... to our direction translation.
+ */
+static const u8 data_dir_flags[] = {
+	[PCI_DMA_BIDIRECTIONAL] = DATA_DIR_BYRECIPIENT,	/* UNSPECIFIED */
+	[PCI_DMA_TODEVICE]      = DATA_DIR_OUT, /* OUTBOUND */
+	[PCI_DMA_FROMDEVICE]    = DATA_DIR_IN, /* INBOUND */
+	[PCI_DMA_NONE]          = DATA_DIR_NONE, /* NO TRANSFER */
+};
+
+static inline int asd_map_scatterlist(struct sas_task *task,
+				      struct sg_el *sg_arr,
+				      unsigned long gfp_flags)
+{
+	struct asd_ascb *ascb = task->lldd_task;
+	struct asd_ha_struct *asd_ha = ascb->ha;
+	struct scatterlist *sc;
+	int num_sg, res;
+
+	if (task->data_dir == PCI_DMA_NONE)
+		return 0;
+
+	if (task->num_scatter == 0) {
+		void *p = task->scatter;
+		dma_addr_t dma = pci_map_single(asd_ha->pcidev, p,
+						task->total_xfer_len,
+						task->data_dir);
+		sg_arr[0].bus_addr = cpu_to_le64((u64)dma);
+		sg_arr[0].size = cpu_to_le32(task->total_xfer_len);
+		sg_arr[0].flags |= ASD_SG_EL_LIST_EOL;
+		return 0;
+	}
+
+	num_sg = pci_map_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
+			    task->data_dir);
+	if (num_sg == 0)
+		return -ENOMEM;
+
+	if (num_sg > 3) {
+		int i;
+
+		ascb->sg_arr = asd_alloc_coherent(asd_ha,
+						  num_sg*sizeof(struct sg_el),
+						  gfp_flags);
+		if (!ascb->sg_arr) {
+			res = -ENOMEM;
+			goto err_unmap;
+		}
+		for (sc = task->scatter, i = 0; i < num_sg; i++, sc++) {
+			struct sg_el *sg =
+				&((struct sg_el *)ascb->sg_arr->vaddr)[i];
+			sg->bus_addr = cpu_to_le64((u64)sg_dma_address(sc));
+			sg->size = cpu_to_le32((u32)sg_dma_len(sc));
+			if (i == num_sg-1)
+				sg->flags |= ASD_SG_EL_LIST_EOL;
+		}
+
+		for (sc = task->scatter, i = 0; i < 2; i++, sc++) {
+			sg_arr[i].bus_addr =
+				cpu_to_le64((u64)sg_dma_address(sc));
+			sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
+		}
+		sg_arr[1].next_sg_offs = 2 * sizeof(*sg_arr);
+		sg_arr[1].flags |= ASD_SG_EL_LIST_EOS;
+
+		memset(&sg_arr[2], 0, sizeof(*sg_arr));
+		sg_arr[2].bus_addr=cpu_to_le64((u64)ascb->sg_arr->dma_handle);
+	} else {
+		int i;
+		for (sc = task->scatter, i = 0; i < num_sg; i++, sc++) {
+			sg_arr[i].bus_addr =
+				cpu_to_le64((u64)sg_dma_address(sc));
+			sg_arr[i].size = cpu_to_le32((u32)sg_dma_len(sc));
+		}
+		sg_arr[i-1].flags |= ASD_SG_EL_LIST_EOL;
+	}
+	
+	return 0;
+err_unmap:
+	pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
+		     task->data_dir);
+	return res;
+}
+
+static inline void asd_unmap_scatterlist(struct asd_ascb *ascb)
+{
+	struct asd_ha_struct *asd_ha = ascb->ha;
+	struct sas_task *task = ascb->uldd_task;
+
+	if (task->data_dir == PCI_DMA_NONE)
+		return;
+
+	if (task->num_scatter == 0) {
+		dma_addr_t dma = (dma_addr_t)
+		       le64_to_cpu(ascb->scb->ssp_task.sg_element[0].bus_addr);
+		pci_unmap_single(ascb->ha->pcidev, dma, task->total_xfer_len,
+				 task->data_dir);
+		return;
+	}
+	
+	asd_free_coherent(asd_ha, ascb->sg_arr);
+	pci_unmap_sg(asd_ha->pcidev, task->scatter, task->num_scatter,
+		     task->data_dir);
+}
+
+/* ---------- Task complete tasklet ---------- */
+
+static void asd_get_response_tasklet(struct asd_ascb *ascb,
+				     struct done_list_struct *dl)
+{
+	struct asd_ha_struct *asd_ha = ascb->ha;
+	struct sas_task *task = ascb->uldd_task;
+	struct task_status_struct *ts = &task->task_status;
+	unsigned long flags;
+	struct tc_resp_sb_struct {
+		__le16 index_escb;
+		u8     len_lsb;
+		u8     flags;
+	} __attribute__ ((packed)) *resp_sb = (void *) dl->status_block;
+
+/* 	int  size   = ((resp_sb->flags & 7) << 8) | resp_sb->len_lsb; */
+	int  edb_id = ((resp_sb->flags & 0x70) >> 4)-1;
+	struct asd_ascb *escb;
+	struct asd_dma_tok *edb;
+	void *r;
+
+	spin_lock_irqsave(&asd_ha->seq.tc_index_lock, flags);
+	escb = asd_tc_index_find(&asd_ha->seq,
+				 (int)le16_to_cpu(resp_sb->index_escb));
+	spin_unlock_irqrestore(&asd_ha->seq.tc_index_lock, flags);
+
+	if (!escb) {
+		ASD_DPRINTK("Uh-oh! No escb for this dl?!\n");
+		return;
+	}
+	
+	ts->buf_valid_size = 0;
+	edb = asd_ha->seq.edb_arr[edb_id + escb->edb_index];
+	r = edb->vaddr;
+	if (task->task_proto == SAS_PROTO_SSP) {
+		struct ssp_response_iu *iu =
+			r + 16 + sizeof(struct ssp_frame_hdr);
+
+		ts->residual = le32_to_cpu(*(__le32 *)r);
+		ts->resp = SAS_TASK_COMPLETE;
+		if (iu->datapres == 0)
+			ts->stat = iu->status;
+		else if (iu->datapres == 1)
+			ts->stat = iu->resp_data[3];
+		else if (iu->datapres == 2) {
+			ts->stat = SAM_CHECK_COND;
+			ts->buf_valid_size = min((u32) SAS_STATUS_BUF_SIZE,
+					 be32_to_cpu(iu->sense_data_len));
+			memcpy(ts->buf, iu->sense_data, ts->buf_valid_size);
+			if (iu->status != SAM_CHECK_COND) {
+				ASD_DPRINTK("device %llx sent sense data, but "
+					    "stat(0x%x) is not CHECK_CONDITION"
+					    "\n",
+					    SAS_ADDR(task->dev->sas_addr),
+					    ts->stat);
+			}
+		}
+	}  else {
+		struct ata_task_resp *resp = (void *) &ts->buf[0];
+		
+		ts->residual = le32_to_cpu(*(__le32 *)r);
+
+		if (SAS_STATUS_BUF_SIZE >= sizeof(*resp)) {
+			resp->frame_len = le16_to_cpu(*(__le16 *)(r+6));
+			memcpy(&resp->ending_fis[0], r+16, 24);
+			ts->buf_valid_size = sizeof(*resp);
+		}
+	}
+
+	asd_invalidate_edb(escb, edb_id);
+}
+
+static void asd_task_tasklet_complete(struct asd_ascb *ascb,
+				      struct done_list_struct *dl)
+{
+	struct sas_task *task = ascb->uldd_task;
+	struct task_status_struct *ts = &task->task_status;
+	unsigned long flags;
+	u8 opcode = dl->opcode;
+
+	asd_can_dequeue(ascb->ha, 1);
+
+Again:
+	switch (opcode) {
+	case TC_NO_ERROR:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAM_GOOD;
+		break;
+	case TC_UNDERRUN:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_DATA_UNDERRUN;
+		ts->residual = le32_to_cpu(*(__le32 *)dl->status_block);
+		break;
+	case TC_OVERRUN:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_DATA_OVERRUN;
+		ts->residual = 0;
+		break;
+	case TC_SSP_RESP:
+	case TC_ATA_RESP:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_PROTO_RESPONSE;
+		asd_get_response_tasklet(ascb, dl);
+		break;
+	case TF_OPEN_REJECT:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_OPEN_REJECT;
+		if (dl->status_block[1] & 2)
+			ts->open_rej_reason = 1 + dl->status_block[2];
+		else if (dl->status_block[1] & 1)
+			ts->open_rej_reason = (dl->status_block[2] >> 4)+10;
+		else
+			ts->open_rej_reason = SAS_OREJ_UNKNOWN;
+		break;
+	case TF_OPEN_TO:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_OPEN_TO;
+		break;
+	case TF_PHY_DOWN:
+	case TU_PHY_DOWN:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_PHY_DOWN;
+		break;
+	case TI_PHY_DOWN:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_PHY_DOWN;
+		break;
+	case TI_BREAK:
+	case TI_PROTO_ERR:
+	case TI_NAK:
+	case TI_ACK_NAK_TO:
+	case TF_SMP_XMIT_RCV_ERR:
+	case TC_ATA_R_ERR_RECV:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_INTERRUPTED;
+		break;
+	case TF_BREAK:
+	case TU_BREAK:		
+	case TU_ACK_NAK_TO:
+	case TF_SMPRSP_TO:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_DEV_NO_RESPONSE;
+		break;
+	case TF_NAK_RECV:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_NAK_R_ERR;
+		break;
+	case TA_I_T_NEXUS_LOSS:
+		opcode = dl->status_block[0];
+		goto Again;
+		break;
+	case TF_INV_CONN_HANDLE:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_DEVICE_UNKNOWN;
+		break;
+	case TF_REQUESTED_N_PENDING:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_PENDING;
+		break;
+	case TC_TASK_CLEARED:
+	case TA_ON_REQ:
+		ts->resp = SAS_TASK_COMPLETE;
+		ts->stat = SAS_ABORTED_TASK;
+		break;
+
+	case TF_NO_SMP_CONN:
+	case TF_TMF_NO_CTX:
+	case TF_TMF_NO_TAG:
+	case TF_TMF_TAG_FREE:
+	case TF_TMF_TASK_DONE:
+	case TF_TMF_NO_CONN_HANDLE:
+	case TF_IRTT_TO:
+	case TF_IU_SHORT:
+	case TF_DATA_OFFS_ERR:
+		ts->resp = SAS_TASK_UNDELIVERED;
+		ts->stat = SAS_DEV_NO_RESPONSE;
+		break;
+
+	case TC_LINK_ADM_RESP:
+	case TC_CONTROL_PHY:
+	case TC_RESUME:
+	case TC_PARTIAL_SG_LIST:
+	default:
+		ASD_DPRINTK("%s: dl opcode: 0x%x?\n", __FUNCTION__, opcode);
+		break;
+	}
+
+	switch (task->task_proto) {
+	case SATA_PROTO:
+	case SAS_PROTO_STP:
+		asd_unbuild_ata_ascb(ascb);
+		break;
+	case SAS_PROTO_SMP:
+		asd_unbuild_smp_ascb(ascb);
+		break;
+	case SAS_PROTO_SSP:
+		asd_unbuild_ssp_ascb(ascb);
+	default:
+		break;
+	}
+
+	spin_lock_irqsave(&task->task_state_lock, flags);
+	task->task_state_flags &= ~SAS_TASK_STATE_PENDING;
+	task->task_state_flags |= SAS_TASK_STATE_DONE;
+	if (unlikely((task->task_state_flags & SAS_TASK_STATE_ABORTED))) {
+		spin_unlock_irqrestore(&task->task_state_lock, flags);
+		ASD_DPRINTK("task 0x%p done with opcode 0x%x resp 0x%x "
+			    "stat 0x%x but aborted by upper layer!\n",
+			    task, opcode, ts->resp, ts->stat);
+		complete(&ascb->completion);
+	} else {
+		spin_unlock_irqrestore(&task->task_state_lock, flags);
+		task->lldd_task = NULL;
+		asd_ascb_free(ascb);
+		mb();
+		task->task_done(task);
+	}
+}
+
+/* ---------- ATA ---------- */
+
+static int asd_build_ata_ascb(struct asd_ascb *ascb, struct sas_task *task,
+			      unsigned long gfp_flags)
+{
+	struct domain_device *dev = task->dev;
+	struct scb *scb;
+	u8     flags;
+	int    res = 0;
+	
+	scb = ascb->scb;
+
+	if (unlikely(task->ata_task.device_control_reg_update))
+		scb->header.opcode = CONTROL_ATA_DEV;
+	else if (dev->sata_dev.command_set == ATA_COMMAND_SET)
+		scb->header.opcode = INITIATE_ATA_TASK;
+	else
+		scb->header.opcode = INITIATE_ATAPI_TASK;
+	
+	scb->ata_task.proto_conn_rate = (1 << 5); /* STP */
+	if (dev->port->oob_mode == SAS_OOB_MODE)
+		scb->ata_task.proto_conn_rate |= dev->linkrate;
+
+	scb->ata_task.total_xfer_len = cpu_to_le32(task->total_xfer_len);
+	scb->ata_task.fis = task->ata_task.fis;
+	scb->ata_task.fis.fis_type = 0x27;
+	if (likely(!task->ata_task.device_control_reg_update))
+		scb->ata_task.fis.flags |= 0x80; /* C=1: update ATA cmd reg */
+	scb->ata_task.fis.flags &= 0xF0; /* PM_PORT field shall be 0 */
+	if (dev->sata_dev.command_set == ATAPI_COMMAND_SET)
+		memcpy(scb->ata_task.atapi_packet, task->ata_task.atapi_packet,
+		       16);
+	scb->ata_task.sister_scb = cpu_to_le16(0xFFFF);
+	scb->ata_task.conn_handle = cpu_to_le16(
+		(u16)(unsigned long)dev->lldd_dev);
+
+	if (likely(!task->ata_task.device_control_reg_update)) {
+		flags = 0;
+		if (task->ata_task.dma_xfer)
+			flags |= DATA_XFER_MODE_DMA;
+		if (task->ata_task.use_ncq &&
+		    dev->sata_dev.command_set != ATAPI_COMMAND_SET)
+			flags |= ATA_Q_TYPE_NCQ;
+		flags |= data_dir_flags[task->data_dir];
+		scb->ata_task.ata_flags = flags;
+	
+		scb->ata_task.retry_count = task->ata_task.retry_count;
+
+		flags = 0;
+		if (task->ata_task.set_affil_pol)
+			flags |= SET_AFFIL_POLICY;
+		if (task->ata_task.stp_affil_pol)
+			flags |= STP_AFFIL_POLICY;
+		scb->ata_task.flags = flags;
+	}
+	ascb->tasklet_complete = asd_task_tasklet_complete;
+
+	if (likely(!task->ata_task.device_control_reg_update))
+		res = asd_map_scatterlist(task, scb->ata_task.sg_element,
+					  gfp_flags);
+
+	return res;
+}
+
+static void asd_unbuild_ata_ascb(struct asd_ascb *a)
+{
+	asd_unmap_scatterlist(a);
+}
+
+/* ---------- SMP ---------- */
+
+static int asd_build_smp_ascb(struct asd_ascb *ascb, struct sas_task *task,
+			      unsigned long gfp_flags)
+{
+	struct asd_ha_struct *asd_ha = ascb->ha;
+	struct domain_device *dev = task->dev;
+	struct scb *scb;
+
+	pci_map_sg(asd_ha->pcidev, &task->smp_task.smp_req, 1,
+		   PCI_DMA_FROMDEVICE);
+	pci_map_sg(asd_ha->pcidev, &task->smp_task.smp_resp, 1,
+		   PCI_DMA_FROMDEVICE);
+
+	scb = ascb->scb;
+
+	scb->header.opcode = INITIATE_SMP_TASK;
+
+	scb->smp_task.proto_conn_rate = dev->linkrate;
+	
+	scb->smp_task.smp_req.bus_addr =
+		cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_req));
+	scb->smp_task.smp_req.size =
+		cpu_to_le32((u32)sg_dma_len(&task->smp_task.smp_req)-4);
+
+	scb->smp_task.smp_resp.bus_addr =
+		cpu_to_le64((u64)sg_dma_address(&task->smp_task.smp_resp));
+	scb->smp_task.smp_resp.size =
+		cpu_to_le32((u32)sg_dma_len(&task->smp_task.smp_resp)-4);
+
+	scb->smp_task.sister_scb = cpu_to_le16(0xFFFF);
+	scb->smp_task.conn_handle = cpu_to_le16((u16)
+						(unsigned long)dev->lldd_dev);
+
+	ascb->tasklet_complete = asd_task_tasklet_complete;
+	
+	return 0;
+}
+
+static void asd_unbuild_smp_ascb(struct asd_ascb *a)
+{
+	struct sas_task *task = a->uldd_task;
+
+	BUG_ON(!task);
+	pci_unmap_sg(a->ha->pcidev, &task->smp_task.smp_req, 1,
+		     PCI_DMA_FROMDEVICE);
+	pci_unmap_sg(a->ha->pcidev, &task->smp_task.smp_resp, 1,
+		     PCI_DMA_FROMDEVICE);
+}
+
+/* ---------- SSP ---------- */
+
+static int asd_build_ssp_ascb(struct asd_ascb *ascb, struct sas_task *task,
+			      unsigned long gfp_flags)
+{
+	struct domain_device *dev = task->dev;
+	struct scb *scb;
+	int    res = 0;
+	
+	scb = ascb->scb;
+
+	scb->header.opcode = INITIATE_SSP_TASK;
+
+	scb->ssp_task.proto_conn_rate  = (1 << 4); /* SSP */
+	scb->ssp_task.proto_conn_rate |= dev->linkrate;
+	scb->ssp_task.total_xfer_len = cpu_to_le32(task->total_xfer_len);
+	scb->ssp_task.ssp_frame.frame_type = SSP_DATA;
+	memcpy(scb->ssp_task.ssp_frame.hashed_dest_addr, dev->hashed_sas_addr,
+	       HASHED_SAS_ADDR_SIZE);
+	memcpy(scb->ssp_task.ssp_frame.hashed_src_addr,
+	       dev->port->ha->hashed_sas_addr, HASHED_SAS_ADDR_SIZE);
+	scb->ssp_task.ssp_frame.tptt = cpu_to_be16(0xFFFF);
+
+	memcpy(scb->ssp_task.ssp_cmd.lun, task->ssp_task.LUN, 8);
+	if (task->ssp_task.enable_first_burst)
+		scb->ssp_task.ssp_cmd.efb_prio_attr |= EFB_MASK;
+	scb->ssp_task.ssp_cmd.efb_prio_attr |= (task->ssp_task.task_prio << 3);
+	scb->ssp_task.ssp_cmd.efb_prio_attr |= (task->ssp_task.task_attr & 7);
+	memcpy(scb->ssp_task.ssp_cmd.cdb, task->ssp_task.cdb, 16);
+
+	scb->ssp_task.sister_scb = cpu_to_le16(0xFFFF);
+	scb->ssp_task.conn_handle = cpu_to_le16(
+		(u16)(unsigned long)dev->lldd_dev);
+	scb->ssp_task.data_dir = data_dir_flags[task->data_dir];
+	scb->ssp_task.retry_count = scb->ssp_task.retry_count;
+
+	ascb->tasklet_complete = asd_task_tasklet_complete;
+
+	res = asd_map_scatterlist(task, scb->ssp_task.sg_element, gfp_flags);
+
+	return res;
+}
+
+static void asd_unbuild_ssp_ascb(struct asd_ascb *a)
+{
+	asd_unmap_scatterlist(a);
+}
+
+/* ---------- Execute Task ---------- */
+
+static inline int asd_can_queue(struct asd_ha_struct *asd_ha, int num)
+{
+	int res = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&asd_ha->seq.pend_q_lock, flags);
+	if ((asd_ha->seq.can_queue - num) < 0)
+		res = -SAS_QUEUE_FULL;
+	else
+		asd_ha->seq.can_queue -= num;
+	spin_unlock_irqrestore(&asd_ha->seq.pend_q_lock, flags);
+	
+	return res;
+}
+
+int asd_execute_task(struct sas_task *task, const int num,
+		     unsigned long gfp_flags)
+{
+	int res = 0;
+	LIST_HEAD(alist);
+	struct sas_task *t = task;
+	struct asd_ascb *ascb = NULL, *a;
+	struct asd_ha_struct *asd_ha = task->dev->port->ha->lldd_ha;
+
+	res = asd_can_queue(asd_ha, num);
+	if (res)
+		return res;
+
+	res = num;
+	ascb = asd_ascb_alloc_list(asd_ha, &res, gfp_flags);
+	if (res) {
+		res = -ENOMEM;
+		goto out_err;
+	}
+
+	__list_add(&alist, ascb->list.prev, &ascb->list);
+	list_for_each_entry(a, &alist, list) {
+		a->uldd_task = t;
+		t->lldd_task = a;
+		t = list_entry(t->list.next, struct sas_task, list);
+	}
+	list_for_each_entry(a, &alist, list) {
+		t = a->uldd_task;
+		a->uldd_timer = 1;
+		if (t->task_proto & SAS_PROTO_STP)
+			t->task_proto = SAS_PROTO_STP;
+		switch (t->task_proto) {
+		case SATA_PROTO:
+		case SAS_PROTO_STP:
+			res = asd_build_ata_ascb(a, t, gfp_flags);
+			break;
+		case SAS_PROTO_SMP:
+			res = asd_build_smp_ascb(a, t, gfp_flags);
+			break;
+		case SAS_PROTO_SSP:
+			res = asd_build_ssp_ascb(a, t, gfp_flags);
+			break;
+		default:
+			asd_printk("unknown sas_task proto: 0x%x\n",
+				   t->task_proto);
+			res = -ENOMEM;
+			break;
+		}
+		if (res)
+			goto out_err_unmap;
+	}
+	list_del_init(&alist);
+
+	res = asd_post_ascb_list(asd_ha, ascb, num);
+	if (unlikely(res)) {
+		a = NULL;
+		__list_add(&alist, ascb->list.prev, &ascb->list);
+		goto out_err_unmap;
+	}
+
+	return 0;
+out_err_unmap:
+	{
+		struct asd_ascb *b = a;
+		list_for_each_entry(a, &alist, list) {
+			if (a == b)
+				break;
+			t = a->uldd_task;
+			switch (t->task_proto) {
+			case SATA_PROTO:
+			case SAS_PROTO_STP:
+				asd_unbuild_ata_ascb(a);
+				break;
+			case SAS_PROTO_SMP:
+				asd_unbuild_smp_ascb(a);
+				break;
+			case SAS_PROTO_SSP:
+				asd_unbuild_ssp_ascb(a);
+			default:
+				break;
+			}
+			t->lldd_task = NULL;
+		}
+	}			
+	list_del_init(&alist);
+out_err:
+	if (ascb)
+		asd_ascb_free_list(ascb);
+	asd_can_dequeue(asd_ha, num);
+	return res;
+}