[PATCH 16/20] snic: reserve tag for TMF

[Hannes Reinecke <hare@suse.de>]

Rather than re-using the failed command the snic driver should
reserve one command for TMFs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 drivers/scsi/snic/snic.h      |  2 +-
 drivers/scsi/snic/snic_main.c |  8 +++++++
 drivers/scsi/snic/snic_scsi.c | 44 +++++++++++++++++------------------
 3 files changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/snic/snic.h b/drivers/scsi/snic/snic.h
index 4ec7e30678e1..28059b66f191 100644
--- a/drivers/scsi/snic/snic.h
+++ b/drivers/scsi/snic/snic.h
@@ -380,7 +380,7 @@ int snic_queuecommand(struct Scsi_Host *, struct scsi_cmnd *);
 int snic_abort_cmd(struct scsi_cmnd *);
 int snic_device_reset(struct scsi_cmnd *);
 int snic_host_reset(struct scsi_cmnd *);
-int snic_reset(struct Scsi_Host *, struct scsi_cmnd *);
+int snic_reset(struct Scsi_Host *);
 void snic_shutdown_scsi_cleanup(struct snic *);
 
 
diff --git a/drivers/scsi/snic/snic_main.c b/drivers/scsi/snic/snic_main.c
index 29d56396058c..3375153dd636 100644
--- a/drivers/scsi/snic/snic_main.c
+++ b/drivers/scsi/snic/snic_main.c
@@ -663,6 +663,14 @@ snic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_get_conf;
 	}
 
+	/*
+	 * Hack alert: reduce can_queue by one after scsi_add_host()
+	 * had been called.
+	 * This essentially reserves the topmost request for TMF.
+	 * Should be replaced by reserved command
+	 * once support is being added.
+	 */
+	shost->can_queue--;
 	snic_set_state(snic, SNIC_ONLINE);
 
 	ret = snic_disc_start(snic);
diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
index 5f17666f3e1d..e69bed855a39 100644
--- a/drivers/scsi/snic/snic_scsi.c
+++ b/drivers/scsi/snic/snic_scsi.c
@@ -1018,17 +1018,6 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
 		      "reset_cmpl: type = %x, hdr_stat = %x, cmnd_id = %x, hid = %x, ctx = %lx\n",
 		      typ, hdr_stat, cmnd_id, hid, ctx);
 
-	/* spl case, host reset issued through ioctl */
-	if (cmnd_id == SCSI_NO_TAG) {
-		rqi = (struct snic_req_info *) ctx;
-		SNIC_HOST_INFO(snic->shost,
-			       "reset_cmpl:Tag %d ctx %lx cmpl stat %s\n",
-			       cmnd_id, ctx, snic_io_status_to_str(hdr_stat));
-		sc = rqi->sc;
-
-		goto ioctl_hba_rst;
-	}
-
 	if (cmnd_id >= snic->max_tag_id) {
 		SNIC_HOST_ERR(snic->shost,
 			      "reset_cmpl: Tag 0x%x out of Range,HdrStat %s\n",
@@ -1039,7 +1028,6 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
 	}
 
 	sc = scsi_host_find_tag(snic->shost, cmnd_id);
-ioctl_hba_rst:
 	if (!sc) {
 		atomic64_inc(&snic->s_stats.io.sc_null);
 		SNIC_HOST_ERR(snic->shost,
@@ -1725,7 +1713,7 @@ snic_dr_clean_single_req(struct snic *snic,
 {
 	struct snic_req_info *rqi = NULL;
 	struct snic_tgt *tgt = NULL;
-	struct scsi_cmnd *sc = NULL;
+	struct scsi_cmnd *sc;
 	spinlock_t *io_lock = NULL;
 	u32 sv_state = 0, tmf = 0;
 	DECLARE_COMPLETION_ONSTACK(tm_done);
@@ -2238,13 +2226,6 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 		goto hba_rst_end;
 	}
 
-	if (snic_cmd_tag(sc) == SCSI_NO_TAG) {
-		memset(scsi_cmd_priv(sc), 0,
-			sizeof(struct snic_internal_io_state));
-		SNIC_HOST_INFO(snic->shost, "issu_hr:Host reset thru ioctl.\n");
-		rqi->sc = sc;
-	}
-
 	req = rqi_to_req(rqi);
 
 	io_lock = snic_io_lock_hash(snic, sc);
@@ -2319,11 +2300,13 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
 } /* end of snic_issue_hba_reset */
 
 int
-snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
+snic_reset(struct Scsi_Host *shost)
 {
 	struct snic *snic = shost_priv(shost);
+	struct scsi_cmnd *sc = NULL;
 	enum snic_state sv_state;
 	unsigned long flags;
+	u32 start_time  = jiffies;
 	int ret = FAILED;
 
 	/* Set snic state as SNIC_FWRESET*/
@@ -2348,6 +2331,19 @@ snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
 	while (atomic_read(&snic->ios_inflight))
 		schedule_timeout(msecs_to_jiffies(1));
 
+	/* The topmost command is reserved for TMF */
+	sc = scsi_host_find_tag(shost, snic->max_tag_id - 1);
+	if (!sc) {
+		SNIC_HOST_ERR(shost,
+			      "reset:Host Reset Failed to allocate sc.\n");
+		spin_lock_irqsave(&snic->snic_lock, flags);
+		snic_set_state(snic, sv_state);
+		spin_unlock_irqrestore(&snic->snic_lock, flags);
+		atomic64_inc(&snic->s_stats.reset.hba_reset_fail);
+		ret = FAILED;
+
+		goto reset_end;
+	}
 	ret = snic_issue_hba_reset(snic, sc);
 	if (ret) {
 		SNIC_HOST_ERR(shost,
@@ -2365,6 +2361,10 @@ snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
 	ret = SUCCESS;
 
 reset_end:
+	SNIC_TRC(shost->host_no, sc ? snic_cmd_tag(sc) : SCSI_NO_TAG,
+		 (ulong) sc, jiffies_to_msecs(jiffies - start_time),
+		 0, 0, 0);
+
 	return ret;
 } /* end of snic_reset */
 
@@ -2387,7 +2387,7 @@ snic_host_reset(struct scsi_cmnd *sc)
 		      sc, sc->cmnd[0], scsi_cmd_to_rq(sc),
 		      snic_cmd_tag(sc), CMD_FLAGS(sc));
 
-	ret = snic_reset(shost, sc);
+	ret = snic_reset(shost);
 
 	SNIC_TRC(shost->host_no, snic_cmd_tag(sc), (ulong) sc,
 		 jiffies_to_msecs(jiffies - start_time),
-- 
2.29.2