Re: [PATCH v4 4/9] snic:Add snic target discovery

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Hi Hannes,

  Thank you for reviewing patches. Please find responses inline.



On 09/04/15 6:29 pm, "Hannes Reinecke" <hare@xxxxxxx> wrote:

>Hi Narsimhulu,
>
>please find some comments inline.
>
>On 04/09/2015 01:49 PM, Narsimhulu Musini wrote:
>> snic_disc.h contains snic target structure definition.
>> 
>> snic_disc.c contains target discovery, setup, lookup, and cleanup
>> 
>> snic_ctl.c contains retrieval of snic capabilities includes
>> max ios, size, SGs per request, and max concurrent requests.
>> 
>> Signed-off-by: Narsimhulu Musini <nmusini@xxxxxxxxx>
>> Signed-off-by: Sesidhar Baddela <sebaddel@xxxxxxxxx>
>> ---
>> * v3
>> - Cleaned up redundant comment.
>> 
>>  drivers/scsi/snic/snic_ctl.c  | 276 +++++++++++++++++++
>>  drivers/scsi/snic/snic_disc.c | 602
>>++++++++++++++++++++++++++++++++++++++++++
>>  drivers/scsi/snic/snic_disc.h | 124 +++++++++
>>  3 files changed, 1002 insertions(+)
>>  create mode 100644 drivers/scsi/snic/snic_ctl.c
>>  create mode 100644 drivers/scsi/snic/snic_disc.c
>>  create mode 100644 drivers/scsi/snic/snic_disc.h
>> 
>> diff --git a/drivers/scsi/snic/snic_ctl.c b/drivers/scsi/snic/snic_ctl.c
>> new file mode 100644
>> index 0000000..4bc55be
>> --- /dev/null
>> +++ b/drivers/scsi/snic/snic_ctl.c
>> @@ -0,0 +1,276 @@
>> +/*
>> + * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
>> + *
>> + * This program is free software; you may 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 SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>> + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>> + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
>> + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
>> + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
>> + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
>> + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
>> + * SOFTWARE.
>> + */
>> +
>> +#include <linux/errno.h>
>> +#include <linux/pci.h>
>> +#include <linux/slab.h>
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/workqueue.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/mempool.h>
>> +#include <scsi/scsi_tcq.h>
>> +#include <linux/ctype.h>
>> +
>> +#include "snic_io.h"
>> +#include "snic.h"
>> +#include "cq_enet_desc.h"
>> +#include "snic_fwint.h"
>> +
>> +/*
>> + * snic_handle_link : Handles link flaps.
>> + */
>> +void
>> +snic_handle_link(struct work_struct *work)
>> +{
>> +	struct snic *snic = container_of(work, struct snic, link_work);
>> +
>> +	if (snic->config.xpt_type != SNIC_DAS) {
>> +		SNIC_HOST_INFO(snic->shost, "Link Event Received.\n");
>> +		SNIC_ASSERT_NOT_IMPL(1);
>> +
>> +		return;
>> +	}
>> +
>> +	snic->link_status = vnic_dev_link_status(snic->vdev);
>> +	snic->link_down_cnt = vnic_dev_link_down_cnt(snic->vdev);
>> +	SNIC_HOST_INFO(snic->shost, "Link Event: Link %s.\n",
>> +		       ((snic->link_status) ? "Up" : "Down"));
>> +}
>> +
>> +
>> +/*
>> + * snic_ver_enc : Encodes version str to int
>> + * version string is similar to netmask string
>> + */
>> +static int
>> +snic_ver_enc(const char *s)
>> +{
>> +	int v[4] = {0};
>> +	int  i = 0, x = 0;
>> +	char c;
>> +	const char *p = s;
>> +
>> +	/* validate version string */
>> +	if ((strlen(s) > 15) || (strlen(s) < 7))
>> +		goto end;
>> +
>> +	while ((c = *p++)) {
>> +		if (c == '.') {
>> +			i++;
>> +			continue;
>> +		}
>> +
>> +		if (i > 4 || !isdigit(c))
>> +			goto end;
>> +
>> +		v[i] = v[i] * 10 + (c - '0');
>> +	}
>> +
>> +	/* validate sub version numbers */
>> +	for (i = 3; i >= 0; i--)
>> +		if (v[i] > 0xff)
>> +			goto end;
>> +
>> +	x |= (v[0] << 24) | v[1] << 16 | v[2] << 8 | v[3];
>> +
>> +end:
>> +	if (x == 0) {
>> +		SNIC_ERR("Invalid version string [%s].\n", s);
>> +
>> +		return -1;
>> +	}
>> +
>> +	return x;
>> +} /* end of snic_ver_enc */
>> +
>> +/*
>> + * snic_qeueue_exch_ver_req :
>> + *
>> + * Queues Exchange Version Request, to communicate host information
>> + * in return, it gets firmware version details
>> + */
>> +int
>> +snic_queue_exch_ver_req(struct snic *snic)
>> +{
>> +	struct snic_req_info *rqi = NULL;
>> +	struct snic_host_req *req = NULL;
>> +	int ret = 0;
>> +
>> +	SNIC_HOST_INFO(snic->shost, "Exch Ver Req Preparing...\n");
>> +
>> +	rqi = snic_req_init(snic, 0);
>> +	if (!rqi) {
>> +		SNIC_HOST_ERR(snic->shost,
>> +			      "Queuing Exch Ver Req failed, err = %d\n",
>> +			      ret);
>> +
>> +		ret = -ENOMEM;
>> +		goto error;
>> +	}
>> +
>> +	req = rqi_to_req(rqi);
>> +
>> +	/* Initialize snic_host_req */
>> +	snic_io_hdr_enc(&req->hdr, SNIC_REQ_EXCH_VER, 0, SCSI_NO_TAG,
>> +			snic->config.hid, 0, (u64)rqi);
>> +	req->u.exch_ver.drvr_ver = snic_ver_enc(SNIC_DRV_VERSION);
>> +	req->u.exch_ver.os_type = SNIC_OS_LINUX;
>> +
>> +	snic_handle_untagged_req(snic, rqi);
>> +
>> +	ret = snic_queue_wq_desc(snic, req, sizeof(*req));
>> +	if (ret) {
>> +		snic_release_untagged_req(snic, rqi);
>> +		SNIC_HOST_ERR(snic->shost,
>> +			      "Queuing Exch Ver Req failed, err = %d\n",
>> +			      ret);
>> +		goto error;
>> +	}
>> +
>> +	SNIC_HOST_INFO(snic->shost, "Exch Ver Req is issued. ret = %d\n",
>>ret);
>> +
>> +error:
>> +	return ret;
>> +} /* end of snic_queue_exch_ver_req */
>> +
>> +/*
>> + * snic_io_exch_ver_cmpl_handler
>> + */
>> +int
>> +snic_io_exch_ver_cmpl_handler(struct snic *snic, struct snic_fw_req
>>*fwreq)
>> +{
>> +	struct snic_req_info *rqi = NULL;
>> +	u8 typ, hdr_stat;
>> +	u32 cmnd_id, hid, max_sgs;
>> +	u64 ctx = 0;
>> +	unsigned long flags;
>> +	int ret = 0;
>> +
>> +	SNIC_HOST_INFO(snic->shost, "Exch Ver Compl Received.\n");
>> +	snic_io_hdr_dec(&fwreq->hdr, &typ, &hdr_stat, &cmnd_id, &hid, &ctx);
>> +	SNIC_BUG_ON(snic->config.hid != hid);
>> +	rqi = (struct snic_req_info *) ctx;
>> +
>> +	if (hdr_stat) {
>> +		SNIC_HOST_ERR(snic->shost,
>> +			      "Exch Ver Completed w/ err status %d\n",
>> +			      hdr_stat);
>> +
>> +		goto exch_cmpl_end;
>> +	}
>> +
>> +	spin_lock_irqsave(&snic->snic_lock, flags);
>> +	snic->fwinfo.fw_ver = fwreq->u.exch_ver_cmpl.version;
>> +	snic->fwinfo.hid = fwreq->u.exch_ver_cmpl.hid;
>> +	snic->fwinfo.max_concur_ios = fwreq->u.exch_ver_cmpl.max_concur_ios;
>> +	snic->fwinfo.max_sgs_per_cmd = fwreq->u.exch_ver_cmpl.max_sgs_per_cmd;
>> +	snic->fwinfo.max_io_sz = fwreq->u.exch_ver_cmpl.max_io_sz;
>> +	snic->fwinfo.max_tgts = fwreq->u.exch_ver_cmpl.max_tgts;
>> +	snic->fwinfo.io_tmo = fwreq->u.exch_ver_cmpl.io_timeout;
>> +
>> +	SNIC_HOST_INFO(snic->shost,
>> +		       "vers %u hid %u max_concur_ios %u max_sgs_per_cmd %u
>>max_io_sz %u max_tgts %u fw tmo %u\n",
>> +		       fwreq->u.exch_ver_cmpl.version,
>> +		       fwreq->u.exch_ver_cmpl.hid,
>> +		       fwreq->u.exch_ver_cmpl.max_concur_ios,
>> +		       fwreq->u.exch_ver_cmpl.max_sgs_per_cmd,
>> +		       fwreq->u.exch_ver_cmpl.max_io_sz,
>> +		       fwreq->u.exch_ver_cmpl.max_tgts,
>> +		       fwreq->u.exch_ver_cmpl.io_timeout);
>> +
>> +	SNIC_HOST_INFO(snic->shost,
>> +		       "HBA Capabilities = 0x%x\n",
>> +		       fwreq->u.exch_ver_cmpl.hba_cap);
>> +
>> +	/* Updating SGList size */
>> +	max_sgs = snic->fwinfo.max_sgs_per_cmd;
>> +	if (max_sgs && max_sgs < SNIC_MAX_SG_DESC_CNT) {
>> +		snic->shost->sg_tablesize = max_sgs;
>> +		SNIC_HOST_INFO(snic->shost, "Max SGs set to %d\n",
>> +			       snic->shost->sg_tablesize);
>> +	} else if (max_sgs > snic->shost->sg_tablesize) {
>> +		SNIC_HOST_INFO(snic->shost,
>> +			       "Target type %d Supports Larger Max SGList %d than driver's
>>Max SG List %d.\n",
>> +			       snic->config.xpt_type, max_sgs,
>> +			       snic->shost->sg_tablesize);
>> +	}
>> +
>> +	if (snic->shost->can_queue > snic->fwinfo.max_concur_ios)
>> +		snic->shost->can_queue = snic->fwinfo.max_concur_ios;
>> +
>> +	snic->shost->max_sectors = snic->fwinfo.max_io_sz >> 9;
>> +	if (snic->fwinfo.wait)
>> +		complete(snic->fwinfo.wait);
>> +
>> +	spin_unlock_irqrestore(&snic->snic_lock, flags);
>> +
>> +exch_cmpl_end:
>> +	snic_release_untagged_req(snic, rqi);
>> +
>> +	SNIC_HOST_INFO(snic->shost, "Exch_cmpl Done, hdr_stat %d.\n",
>>hdr_stat);
>> +
>> +	return ret;
>> +} /* end of snic_io_exch_ver_cmpl_handler */
>> +
>> +/*
>> + * snic_get_conf
>> + *
>> + * Synchronous call, and Retrieves snic params.
>> + */
>> +int
>> +snic_get_conf(struct snic *snic)
>> +{
>> +	DECLARE_COMPLETION_ONSTACK(wait);
>> +	unsigned long flags;
>> +	int ret;
>> +	int nr_retries = 3;
>> +
>> +	SNIC_HOST_INFO(snic->shost, "Retrieving snic params.\n");
>> +	spin_lock_irqsave(&snic->snic_lock, flags);
>> +	memset(&snic->fwinfo, 0, sizeof(snic->fwinfo));
>> +	snic->fwinfo.wait = &wait;
>> +	spin_unlock_irqrestore(&snic->snic_lock, flags);
>> +
>> +	/* Additional delay to handle HW Resource initialization. */
>> +	msleep(50);
>> +
>> +	/*
>> +	 * Exch ver req can be ignored by FW, if HW Resource initialization
>> +	 * is in progress, Hence retry.
>> +	 */
>> +	do {
>> +		ret = snic_queue_exch_ver_req(snic);
>> +		if (ret)
>> +			return ret;
>> +
>> +		wait_for_completion_timeout(&wait, msecs_to_jiffies(2000));
>> +		spin_lock_irqsave(&snic->snic_lock, flags);
>> +		ret = (snic->fwinfo.fw_ver != 0) ? 0 : -ETIMEDOUT;
>> +		if (ret)
>> +			SNIC_HOST_ERR(snic->shost,
>> +				      "Failed to retrieve snic params,\n");
>> +
>> +		/* Unset fwinfo.wait, on success or on last retry */
>> +		if (ret == 0 || nr_retries == 1)
>> +			snic->fwinfo.wait = NULL;
>> +
>> +		spin_unlock_irqrestore(&snic->snic_lock, flags);
>> +	} while (ret && --nr_retries);
>> +
>> +	return ret;
>> +} /* end of snic_get_info */
>> diff --git a/drivers/scsi/snic/snic_disc.c
>>b/drivers/scsi/snic/snic_disc.c
>> new file mode 100644
>> index 0000000..b6b6cca
>> --- /dev/null
>> +++ b/drivers/scsi/snic/snic_disc.c
>> @@ -0,0 +1,602 @@
>> +/*
>> + * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
>> + *
>> + * This program is free software; you may 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 SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
>> + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
>> + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
>> + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
>> + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
>> + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
>> + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
>> + * SOFTWARE.
>> + */
>> +
>> +#include <linux/errno.h>
>> +#include <linux/mempool.h>
>> +
>> +#include <scsi/scsi_tcq.h>
>> +
>> +#include "snic_disc.h"
>> +#include "snic.h"
>> +#include "snic_io.h"
>> +
>> +
>> +/* snic target types */
>> +static const char * const snic_tgt_type_str[] = {
>> +	[SNIC_TGT_DAS] = "DAS",
>> +	[SNIC_TGT_SAN] = "SAN",
>> +};
>> +
>> +static inline const char *
>> +snic_tgt_type_to_str(int typ)
>> +{
>> +	return ((typ > SNIC_TGT_NONE && typ <= SNIC_TGT_SAN) ?
>> +		 snic_tgt_type_str[typ] : "Unknown");
>> +}
>> +
>> +static const char * const snic_tgt_state_str[] = {
>> +	[SNIC_TGT_STAT_INIT]	= "INIT",
>> +	[SNIC_TGT_STAT_ONLINE]	= "ONLINE",
>> +	[SNIC_TGT_STAT_OFFLINE]	= "OFFLINE",
>> +	[SNIC_TGT_STAT_DEL]	= "DELETION IN PROGRESS",
>> +};
>> +
>> +const char *
>> +snic_tgt_state_to_str(int state)
>> +{
>> +	return ((state >= SNIC_TGT_STAT_INIT && state <= SNIC_TGT_STAT_DEL) ?
>> +		snic_tgt_state_str[state] : "UNKNOWN");
>> +}
>> +
>> +/*
>> + * Initiate report_tgt req desc
>> + */
>> +static void
>> +snic_report_tgt_init(struct snic_host_req *req, u32 hid, u8 *buf, u32
>>len,
>> +		     u64 rsp_buf_pa, u64 ctx)
>> +{
>> +	struct snic_sg_desc *sgd = NULL;
>> +
>> +
>> +	snic_io_hdr_enc(&req->hdr, SNIC_REQ_REPORT_TGTS, 0, SCSI_NO_TAG, hid,
>> +			1, ctx);
>> +
>> +	req->u.rpt_tgts.sg_cnt = 1;
>> +	sgd = req_to_sgl(req);
>> +	sgd[0].addr = cpu_to_le64(rsp_buf_pa);
>> +	sgd[0].len = cpu_to_le32(len);
>> +	sgd[0]._resvd = 0;
>> +	req->u.rpt_tgts.sg_addr = (u64) sgd;
>> +}
>> +
>> +/*
>> + * snic_queue_report_tgt_req: Queues report target request.
>> + */
>> +static int
>> +snic_queue_report_tgt_req(struct snic *snic)
>> +{
>> +	struct snic_req_info *rqi = NULL;
>> +	u32 ntgts, buf_len = 0;
>> +	u8 *buf = NULL;
>> +	dma_addr_t pa = 0;
>> +	int ret = 0;
>> +
>> +	rqi = snic_req_init(snic, 1);
>> +	if (!rqi) {
>> +		ret = -ENOMEM;
>> +		goto error;
>> +	}
>> +
>> +	if (snic->fwinfo.max_tgts)
>> +		ntgts = min_t(u32, snic->fwinfo.max_tgts, snic->shost->max_id);
>> +	else
>> +		ntgts = snic->shost->max_id;
>> +
>> +	/* Allocate Response Buffer */
>> +	SNIC_BUG_ON(ntgts == 0);
>> +	buf_len = ntgts * sizeof(struct snic_tgt_id) + SNIC_SG_DESC_ALIGN;
>> +
>> +	buf = kzalloc(buf_len, GFP_KERNEL|GFP_DMA);
>> +	if (!buf) {
>> +		snic_req_free(snic, rqi);
>> +		SNIC_HOST_ERR(snic->shost, "Resp Buf Alloc Failed.\n");
>> +
>> +		ret = -ENOMEM;
>> +		goto error;
>> +	}
>> +
>> +	SNIC_BUG_ON((((unsigned long)buf) % SNIC_SG_DESC_ALIGN) != 0);
>> +
>> +	pa = pci_map_single(snic->pdev, buf, buf_len, PCI_DMA_FROMDEVICE);
>> +	if (pci_dma_mapping_error(snic->pdev, pa)) {
>> +		kfree(buf);
>> +		snic_req_free(snic, rqi);
>> +		SNIC_HOST_ERR(snic->shost,
>> +			      "Rpt-tgt rspbuf %p: PCI DMA Mapping Failed\n",
>> +			      buf);
>> +		ret = -EINVAL;
>> +
>> +		goto error;
>> +	}
>> +
>> +
>> +	SNIC_BUG_ON(pa == 0);
>> +	rqi->sge_va = (u64) buf;
>> +
>> +	snic_report_tgt_init(rqi->req,
>> +			     snic->config.hid,
>> +			     buf,
>> +			     buf_len,
>> +			     (u64)pa,
>> +			     (u64)rqi);
>> +
>> +	snic_handle_untagged_req(snic, rqi);
>> +
>> +	ret = snic_queue_wq_desc(snic, rqi->req, rqi->req_len);
>> +	if (ret) {
>> +		pci_unmap_single(snic->pdev, pa, buf_len, PCI_DMA_FROMDEVICE);
>> +		kfree(buf);
>> +		rqi->sge_va = 0;
>> +		snic_release_untagged_req(snic, rqi);
>> +		SNIC_HOST_ERR(snic->shost, "Queuing Report Tgts Failed.\n");
>> +
>> +		goto error;
>> +	}
>> +
>> +	SNIC_DISC_DBG(snic->shost, "Report Targets Issued.\n");
>> +
>> +	return ret;
>> +
>> +error:
>> +	SNIC_HOST_ERR(snic->shost,
>> +		      "Queuing Report Targets Failed, err = %d\n",
>> +		      ret);
>> +	return ret;
>> +} /* end of snic_queue_report_tgt_req */
>> +
>> +/* call into SML */
>> +static void
>> +snic_scsi_scan_tgt(struct work_struct *work)
>> +{
>> +	struct snic_tgt *tgt = container_of(work, struct snic_tgt, scan_work);
>> +	struct Scsi_Host *shost = dev_to_shost(&tgt->dev);
>> +	unsigned long flags;
>> +
>> +	SNIC_HOST_INFO(shost, "Scanning Target id 0x%x\n", tgt->id);
>> +	scsi_scan_target(&tgt->dev,
>> +			 tgt->channel,
>> +			 tgt->scsi_tgt_id,
>> +			 SCAN_WILD_CARD,
>> +			 1);
>> +
>> +	spin_lock_irqsave(shost->host_lock, flags);
>> +	tgt->flags &= ~SNIC_TGT_SCAN_PENDING;
>> +	spin_unlock_irqrestore(shost->host_lock, flags);
>> +} /* end of snic_scsi_scan_tgt */
>> +
>> +/*
>> + * snic_tgt_lookup :
>> + */
>> +static struct snic_tgt *
>> +snic_tgt_lookup(struct snic *snic, struct snic_tgt_id *tgtid)
>> +{
>> +	struct list_head *cur, *nxt;
>> +	struct snic_tgt *tgt = NULL;
>> +
>> +	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
>> +		tgt = list_entry(cur, struct snic_tgt, list);
>> +		if (tgt->id == tgtid->tgt_id)
>> +			return tgt;
>> +		tgt = NULL;
>> +	}
>> +
>> +	return tgt;
>> +} /* end of snic_tgt_lookup */
>> +
>> +/*
>> + * snic_tgt_dev_release : Called on dropping last ref for snic_tgt
>>object
>> + */
>> +void
>> +snic_tgt_dev_release(struct device *dev)
>> +{
>> +	struct snic_tgt *tgt = dev_to_tgt(dev);
>> +
>> +	SNIC_HOST_INFO(snic_tgt_to_shost(tgt),
>> +		       "Target Device ID %d (%s) Permanently Deleted.\n",
>> +		       tgt->id,
>> +		       dev_name(dev));
>> +
>> +	SNIC_BUG_ON(!list_empty(&tgt->list));
>> +	kfree(tgt);
>> +}
>> +
>> +/*
>> + * snic_tgt_del : work function to delete snic_tgt
>> + */
>> +static void
>> +snic_tgt_del(struct work_struct *work)
>> +{
>> +	struct snic_tgt *tgt = container_of(work, struct snic_tgt, del_work);
>> +	struct Scsi_Host *shost = snic_tgt_to_shost(tgt);
>> +
>> +	if (tgt->flags & SNIC_TGT_SCAN_PENDING)
>> +		scsi_flush_work(shost);
>> +
>> +	/* Block IOs on child devices, stops new IOs */
>> +	scsi_target_block(&tgt->dev);
>> +
>> +	/* Cleanup IOs */
>> +	snic_tgt_scsi_abort_io(tgt);
>> +
>> +	/* Unblock IOs now, to flush if there are any. */
>> +	scsi_target_unblock(&tgt->dev, SDEV_TRANSPORT_OFFLINE);
>> +
>> +	/* Delete SCSI Target and sdevs */
>> +	scsi_remove_target(&tgt->dev);  /* ?? */
>> +	device_del(&tgt->dev);
>> +	put_device(&tgt->dev);
>> +} /* end of snic_tgt_del */
>> +
>> +/* snic_tgt_create: checks for existence of snic_tgt, if it doesn't
>> + * it creates one.
>> + */
>> +static struct snic_tgt *
>> +snic_tgt_create(struct snic *snic, struct snic_tgt_id *tgtid)
>> +{
>> +	struct snic_tgt *tgt = NULL;
>> +	unsigned long flags;
>> +	int ret;
>> +
>> +	tgt = snic_tgt_lookup(snic, tgtid);
>> +	if (tgt) {
>> +		/* update the information if required */
>> +		return tgt;
>> +	}
>> +
>> +	tgt = kzalloc(sizeof(*tgt), GFP_KERNEL);
>> +	if (!tgt) {
>> +		SNIC_HOST_ERR(snic->shost, "Failure to allocate snic_tgt.\n");
>> +		ret = -ENOMEM;
>> +
>> +		return tgt;
>> +	}
>> +
>> +	INIT_LIST_HEAD(&tgt->list);
>> +	tgt->id = tgtid->tgt_id;
>> +	tgt->channel = 0;
>> +
>> +	SNIC_BUG_ON(tgtid->tgt_type > SNIC_TGT_SAN);
>> +	tgt->tdata.typ = tgtid->tgt_type;
>> +
>> +	/*
>> +	 * Plugging into SML Device Tree
>> +	 */
>> +	tgt->tdata.disc_id = 0;
>> +	tgt->state = SNIC_TGT_STAT_INIT;
>> +	device_initialize(&tgt->dev);
>> +	tgt->dev.parent = get_device(&snic->shost->shost_gendev);
>> +	tgt->dev.release = snic_tgt_dev_release;
>Why do you use your own scsi target instantiation here?
>If it's equivalent to the scsi target than you should rather use the
>'scsi_target' structure here and attach driver-specific information
>to either hostdata or starget_data.
I got your idea, we followed an approach similar to fc (fc_rport_create()
in scsi_transport_fc.c).
Both are valid approaches. We opted for current approach, and gone through
good amount of testing.
I would like to keep the way it is. Please share your thoughts.
>
>Cheers,
>
>Hannes
>-- 
>Dr. Hannes Reinecke		      zSeries & Storage
>hare@xxxxxxx			      +49 911 74053 688
>SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
>GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
Thanks
Narsimhulu
>

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