5 files changed, 316 insertions, 8 deletions

diff --git a/drivers/scsi/qla2xxx/qla_dbg.c b/drivers/scsi/qla2xxx/qla_dbg.c
index 83d47ab3fd1e..d77fe43793b6 100644
--- a/drivers/scsi/qla2xxx/qla_dbg.c
+++ b/drivers/scsi/qla2xxx/qla_dbg.c
@@ -19,7 +19,7 @@
  * | Device Discovery             |       0x2016       | 0x2020-0x2022, |
  * |                              |                    | 0x2011-0x2012, |
  * |                              |                    | 0x2099-0x20a4  |
- * | Queue Command and IO tracing |       0x3059       | 0x3006-0x300b  |
+ * | Queue Command and IO tracing |       0x3059       | 0x300b         |
  * |                              |                    | 0x3027-0x3028  |
  * |                              |                    | 0x303d-0x3041  |
  * |                              |                    | 0x302d,0x3033  |
@@ -67,7 +67,7 @@
  * |                              |                    | 0xd031-0xd0ff	|
  * |                              |                    | 0xd101-0xd1fe	|
  * |                              |                    | 0xd214-0xd2fe	|
- * | Target Mode		  |	  0xe078       |		|
+ * | Target Mode		  |	  0xe079       |		|
  * | Target Mode Management	  |	  0xf072       | 0xf002		|
  * |                              |                    | 0xf046-0xf049  |
  * | Target Mode Task Management  |	  0x1000b      |		|
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index b048841a5360..5f6b2960cccb 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2776,6 +2776,9 @@ struct qla_statistics {
 	uint32_t control_requests;
 
 	uint64_t jiffies_at_last_reset;
+	uint32_t stat_max_pend_cmds;
+	uint32_t stat_max_qfull_cmds_alloc;
+	uint32_t stat_max_qfull_cmds_dropped;
 };
 
 struct bidi_statistics {
@@ -2898,8 +2901,22 @@ struct qlt_hw_data {
 	uint8_t saved_add_firmware_options[2];
 
 	uint8_t tgt_node_name[WWN_SIZE];
+
+	struct list_head q_full_list;
+	uint32_t num_pend_cmds;
+	uint32_t num_qfull_cmds_alloc;
+	uint32_t num_qfull_cmds_dropped;
+	spinlock_t q_full_lock;
+	uint32_t leak_exchg_thresh_hold;
 };
 
+#define MAX_QFULL_CMDS_ALLOC	8192
+#define Q_FULL_THRESH_HOLD_PERCENT 90
+#define Q_FULL_THRESH_HOLD(ha) \
+	((ha->fw_xcb_count/100) * Q_FULL_THRESH_HOLD_PERCENT)
+
+#define LEAK_EXCHG_THRESH_HOLD_PERCENT 75	/* 75 percent */
+
 /*
  * Qlogic host adapter specific data structure.
 */
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 34e56e2faa0e..dabd25429c58 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -2398,6 +2398,8 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	    "Memory allocated for ha=%p.\n", ha);
 	ha->pdev = pdev;
 	ha->tgt.enable_class_2 = ql2xenableclass2;
+	INIT_LIST_HEAD(&ha->tgt.q_full_list);
+	spin_lock_init(&ha->tgt.q_full_lock);
 
 	/* Clear our data area */
 	ha->bars = bars;
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index ccd0ca25db54..9f248e7505ff 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -59,6 +59,8 @@ MODULE_PARM_DESC(qlini_mode,
 
 int ql2x_ini_mode = QLA2XXX_INI_MODE_EXCLUSIVE;
 
+static int temp_sam_status = SAM_STAT_BUSY;
+
 /*
  * From scsi/fc/fc_fcp.h
  */
@@ -108,6 +110,8 @@ static void qlt_reject_free_srr_imm(struct scsi_qla_host *ha,
 	struct qla_tgt_srr_imm *imm, int ha_lock);
 static void qlt_abort_cmd_on_host_reset(struct scsi_qla_host *vha,
 	struct qla_tgt_cmd *cmd);
+static void qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
+	struct atio_from_isp *atio, uint16_t status, int qfull);
 /*
  * Global Variables
  */
@@ -185,6 +189,27 @@ struct scsi_qla_host *qlt_find_host_by_vp_idx(struct scsi_qla_host *vha,
 	return NULL;
 }
 
+static inline void qlt_incr_num_pend_cmds(struct scsi_qla_host *vha)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&vha->hw->tgt.q_full_lock, flags);
+
+	vha->hw->tgt.num_pend_cmds++;
+	if (vha->hw->tgt.num_pend_cmds > vha->hw->qla_stats.stat_max_pend_cmds)
+		vha->hw->qla_stats.stat_max_pend_cmds =
+			vha->hw->tgt.num_pend_cmds;
+	spin_unlock_irqrestore(&vha->hw->tgt.q_full_lock, flags);
+}
+static inline void qlt_decr_num_pend_cmds(struct scsi_qla_host *vha)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&vha->hw->tgt.q_full_lock, flags);
+	vha->hw->tgt.num_pend_cmds--;
+	spin_unlock_irqrestore(&vha->hw->tgt.q_full_lock, flags);
+}
+
 void qlt_24xx_atio_pkt_all_vps(struct scsi_qla_host *vha,
 	struct atio_from_isp *atio)
 {
@@ -2683,10 +2708,14 @@ static void qlt_send_term_exchange(struct scsi_qla_host *vha,
 
 	if (ha_locked) {
 		rc = __qlt_send_term_exchange(vha, cmd, atio);
+		if (rc == -ENOMEM)
+			qlt_alloc_qfull_cmd(vha, atio, 0, 0);
 		goto done;
 	}
 	spin_lock_irqsave(&vha->hw->hardware_lock, flags);
 	rc = __qlt_send_term_exchange(vha, cmd, atio);
+	if (rc == -ENOMEM)
+		qlt_alloc_qfull_cmd(vha, atio, 0, 0);
 	spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);
 done:
 	/*
@@ -2711,6 +2740,53 @@ done:
 	return;
 }
 
+static void qlt_init_term_exchange(struct scsi_qla_host *vha)
+{
+	struct list_head free_list;
+	struct qla_tgt_cmd *cmd, *tcmd;
+
+	vha->hw->tgt.leak_exchg_thresh_hold =
+	    (vha->hw->fw_xcb_count/100) * LEAK_EXCHG_THRESH_HOLD_PERCENT;
+
+	cmd = tcmd = NULL;
+	if (!list_empty(&vha->hw->tgt.q_full_list)) {
+		INIT_LIST_HEAD(&free_list);
+		list_splice_init(&vha->hw->tgt.q_full_list, &free_list);
+
+		list_for_each_entry_safe(cmd, tcmd, &free_list, cmd_list) {
+			list_del(&cmd->cmd_list);
+			/* This cmd was never sent to TCM.  There is no need
+			 * to schedule free or call free_cmd
+			 */
+			qlt_free_cmd(cmd);
+			vha->hw->tgt.num_qfull_cmds_alloc--;
+		}
+	}
+	vha->hw->tgt.num_qfull_cmds_dropped = 0;
+}
+
+static void qlt_chk_exch_leak_thresh_hold(struct scsi_qla_host *vha)
+{
+	uint32_t total_leaked;
+
+	total_leaked = vha->hw->tgt.num_qfull_cmds_dropped;
+
+	if (vha->hw->tgt.leak_exchg_thresh_hold &&
+	    (total_leaked > vha->hw->tgt.leak_exchg_thresh_hold)) {
+
+		ql_dbg(ql_dbg_tgt, vha, 0xe079,
+		    "Chip reset due to exchange starvation: %d/%d.\n",
+		    total_leaked, vha->hw->fw_xcb_count);
+
+		if (IS_P3P_TYPE(vha->hw))
+			set_bit(FCOE_CTX_RESET_NEEDED, &vha->dpc_flags);
+		else
+			set_bit(ISP_ABORT_NEEDED, &vha->dpc_flags);
+		qla2xxx_wake_dpc(vha);
+	}
+
+}
+
 void qlt_free_cmd(struct qla_tgt_cmd *cmd)
 {
 	struct qla_tgt_sess *sess = cmd->sess;
@@ -2720,6 +2796,9 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd)
 	    __func__, &cmd->se_cmd,
 	    be16_to_cpu(cmd->atio.u.isp24.fcp_hdr.ox_id));
 
+	if (!cmd->q_full)
+		qlt_decr_num_pend_cmds(cmd->vha);
+
 	BUG_ON(cmd->sg_mapped);
 	if (unlikely(cmd->free_sg))
 		kfree(cmd->sg);
@@ -3078,7 +3157,7 @@ static void qlt_do_ctio_completion(struct scsi_qla_host *vha, uint32_t handle,
 		 * level.
 		 */
 		if ((cmd->state != QLA_TGT_STATE_NEED_DATA) &&
-			(cmd->state != QLA_TGT_STATE_ABORTED)) {
+		    (cmd->state != QLA_TGT_STATE_ABORTED)) {
 			if (qlt_term_ctio_exchange(vha, ctio, cmd, status))
 				return;
 		}
@@ -3114,6 +3193,7 @@ skip_term:
 		dump_stack();
 	}
 
+
 	ha->tgt.tgt_ops->free_cmd(cmd);
 }
 
@@ -3211,6 +3291,8 @@ out_term:
 	 */
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	qlt_send_term_exchange(vha, NULL, &cmd->atio, 1);
+
+	qlt_decr_num_pend_cmds(vha);
 	percpu_ida_free(&sess->se_sess->sess_tag_pool, cmd->se_cmd.map_tag);
 	ha->tgt.tgt_ops->put_sess(sess);
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
@@ -3241,6 +3323,7 @@ static struct qla_tgt_cmd *qlt_get_tag(scsi_qla_host_t *vha,
 	memcpy(&cmd->atio, atio, sizeof(*atio));
 	cmd->state = QLA_TGT_STATE_NEW;
 	cmd->tgt = vha->vha_tgt.qla_tgt;
+	qlt_incr_num_pend_cmds(vha);
 	cmd->vha = vha;
 	cmd->se_cmd.map_tag = tag;
 	cmd->sess = sess;
@@ -4184,7 +4267,7 @@ static void qlt_handle_imm_notify(struct scsi_qla_host *vha,
  * ha->hardware_lock supposed to be held on entry. Might drop it, then reaquire
  * This function sends busy to ISP 2xxx or 24xx.
  */
-static void qlt_send_busy(struct scsi_qla_host *vha,
+static int __qlt_send_busy(struct scsi_qla_host *vha,
 	struct atio_from_isp *atio, uint16_t status)
 {
 	struct ctio7_to_24xx *ctio24;
@@ -4196,7 +4279,7 @@ static void qlt_send_busy(struct scsi_qla_host *vha,
 	    atio->u.isp24.fcp_hdr.s_id);
 	if (!sess) {
 		qlt_send_term_exchange(vha, NULL, atio, 1);
-		return;
+		return 0;
 	}
 	/* Sending marker isn't necessary, since we called from ISR */
 
@@ -4205,7 +4288,7 @@ static void qlt_send_busy(struct scsi_qla_host *vha,
 		ql_dbg(ql_dbg_io, vha, 0x3063,
 		    "qla_target(%d): %s failed: unable to allocate "
 		    "request packet", vha->vp_idx, __func__);
-		return;
+		return -ENOMEM;
 	}
 
 	pkt->entry_count = 1;
@@ -4237,6 +4320,189 @@ static void qlt_send_busy(struct scsi_qla_host *vha,
 		ctio24->u.status1.scsi_status |= SS_RESIDUAL_UNDER;
 
 	qla2x00_start_iocbs(vha, vha->req);
+	return 0;
+}
+
+/*
+ * This routine is used to allocate a command for either a QFull condition
+ * (ie reply SAM_STAT_BUSY) or to terminate an exchange that did not go
+ * out previously.
+ */
+static void
+qlt_alloc_qfull_cmd(struct scsi_qla_host *vha,
+	struct atio_from_isp *atio, uint16_t status, int qfull)
+{
+	struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
+	struct qla_hw_data *ha = vha->hw;
+	struct qla_tgt_sess *sess;
+	struct se_session *se_sess;
+	struct qla_tgt_cmd *cmd;
+	int tag;
+
+	if (unlikely(tgt->tgt_stop)) {
+		ql_dbg(ql_dbg_io, vha, 0x300a,
+			"New command while device %p is shutting down\n", tgt);
+		return;
+	}
+
+	if ((vha->hw->tgt.num_qfull_cmds_alloc + 1) > MAX_QFULL_CMDS_ALLOC) {
+		vha->hw->tgt.num_qfull_cmds_dropped++;
+		if (vha->hw->tgt.num_qfull_cmds_dropped >
+			vha->hw->qla_stats.stat_max_qfull_cmds_dropped)
+			vha->hw->qla_stats.stat_max_qfull_cmds_dropped =
+				vha->hw->tgt.num_qfull_cmds_dropped;
+
+		ql_dbg(ql_dbg_io, vha, 0x3068,
+			"qla_target(%d): %s: QFull CMD dropped[%d]\n",
+			vha->vp_idx, __func__,
+			vha->hw->tgt.num_qfull_cmds_dropped);
+
+		qlt_chk_exch_leak_thresh_hold(vha);
+		return;
+	}
+
+	sess = ha->tgt.tgt_ops->find_sess_by_s_id
+		(vha, atio->u.isp24.fcp_hdr.s_id);
+	if (!sess)
+		return;
+
+	se_sess = sess->se_sess;
+
+	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, TASK_RUNNING);
+	if (tag < 0)
+		return;
+
+	cmd = &((struct qla_tgt_cmd *)se_sess->sess_cmd_map)[tag];
+	if (!cmd) {
+		ql_dbg(ql_dbg_io, vha, 0x3009,
+			"qla_target(%d): %s: Allocation of cmd failed\n",
+			vha->vp_idx, __func__);
+
+		vha->hw->tgt.num_qfull_cmds_dropped++;
+		if (vha->hw->tgt.num_qfull_cmds_dropped >
+			vha->hw->qla_stats.stat_max_qfull_cmds_dropped)
+			vha->hw->qla_stats.stat_max_qfull_cmds_dropped =
+				vha->hw->tgt.num_qfull_cmds_dropped;
+
+		qlt_chk_exch_leak_thresh_hold(vha);
+		return;
+	}
+
+	memset(cmd, 0, sizeof(struct qla_tgt_cmd));
+
+	qlt_incr_num_pend_cmds(vha);
+	INIT_LIST_HEAD(&cmd->cmd_list);
+	memcpy(&cmd->atio, atio, sizeof(*atio));
+
+	cmd->tgt = vha->vha_tgt.qla_tgt;
+	cmd->vha = vha;
+	cmd->reset_count = vha->hw->chip_reset;
+	cmd->q_full = 1;
+
+	if (qfull) {
+		cmd->q_full = 1;
+		/* NOTE: borrowing the state field to carry the status */
+		cmd->state = status;
+	} else
+		cmd->term_exchg = 1;
+
+	list_add_tail(&cmd->cmd_list, &vha->hw->tgt.q_full_list);
+
+	vha->hw->tgt.num_qfull_cmds_alloc++;
+	if (vha->hw->tgt.num_qfull_cmds_alloc >
+		vha->hw->qla_stats.stat_max_qfull_cmds_alloc)
+		vha->hw->qla_stats.stat_max_qfull_cmds_alloc =
+			vha->hw->tgt.num_qfull_cmds_alloc;
+}
+
+int
+qlt_free_qfull_cmds(struct scsi_qla_host *vha)
+{
+	struct qla_hw_data *ha = vha->hw;
+	unsigned long flags;
+	struct qla_tgt_cmd *cmd, *tcmd;
+	struct list_head free_list;
+	int rc = 0;
+
+	if (list_empty(&ha->tgt.q_full_list))
+		return 0;
+
+	INIT_LIST_HEAD(&free_list);
+
+	spin_lock_irqsave(&vha->hw->hardware_lock, flags);
+
+	if (list_empty(&ha->tgt.q_full_list)) {
+		spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);
+		return 0;
+	}
+
+	list_for_each_entry_safe(cmd, tcmd, &ha->tgt.q_full_list, cmd_list) {
+		if (cmd->q_full)
+			/* cmd->state is a borrowed field to hold status */
+			rc = __qlt_send_busy(vha, &cmd->atio, cmd->state);
+		else if (cmd->term_exchg)
+			rc = __qlt_send_term_exchange(vha, NULL, &cmd->atio);
+
+		if (rc == -ENOMEM)
+			break;
+
+		if (cmd->q_full)
+			ql_dbg(ql_dbg_io, vha, 0x3006,
+			    "%s: busy sent for ox_id[%04x]\n", __func__,
+			    be16_to_cpu(cmd->atio.u.isp24.fcp_hdr.ox_id));
+		else if (cmd->term_exchg)
+			ql_dbg(ql_dbg_io, vha, 0x3007,
+			    "%s: Term exchg sent for ox_id[%04x]\n", __func__,
+			    be16_to_cpu(cmd->atio.u.isp24.fcp_hdr.ox_id));
+		else
+			ql_dbg(ql_dbg_io, vha, 0x3008,
+			    "%s: Unexpected cmd in QFull list %p\n", __func__,
+			    cmd);
+
+		list_del(&cmd->cmd_list);
+		list_add_tail(&cmd->cmd_list, &free_list);
+
+		/* piggy back on hardware_lock for protection */
+		vha->hw->tgt.num_qfull_cmds_alloc--;
+	}
+	spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);
+
+	cmd = NULL;
+
+	list_for_each_entry_safe(cmd, tcmd, &free_list, cmd_list) {
+		list_del(&cmd->cmd_list);
+		/* This cmd was never sent to TCM.  There is no need
+		 * to schedule free or call free_cmd
+		 */
+		qlt_free_cmd(cmd);
+	}
+	return rc;
+}
+
+static void
+qlt_send_busy(struct scsi_qla_host *vha,
+	struct atio_from_isp *atio, uint16_t status)
+{
+	int rc = 0;
+
+	rc = __qlt_send_busy(vha, atio, status);
+	if (rc == -ENOMEM)
+		qlt_alloc_qfull_cmd(vha, atio, status, 1);
+}
+
+static int
+qlt_chk_qfull_thresh_hold(struct scsi_qla_host *vha,
+	struct atio_from_isp *atio)
+{
+	struct qla_hw_data *ha = vha->hw;
+	uint16_t status;
+
+	if (ha->tgt.num_pend_cmds < Q_FULL_THRESH_HOLD(ha))
+		return 0;
+
+	status = temp_sam_status;
+	qlt_send_busy(vha, atio, status);
+	return 1;
 }
 
 /* ha->hardware_lock supposed to be held on entry */
@@ -4271,10 +4537,19 @@ static void qlt_24xx_atio_pkt(struct scsi_qla_host *vha,
 			qlt_send_busy(vha, atio, SAM_STAT_TASK_SET_FULL);
 			break;
 		}
-		if (likely(atio->u.isp24.fcp_cmnd.task_mgmt_flags == 0))
+
+
+
+		if (likely(atio->u.isp24.fcp_cmnd.task_mgmt_flags == 0)) {
+			rc = qlt_chk_qfull_thresh_hold(vha, atio);
+			if (rc != 0) {
+				tgt->irq_cmd_count--;
+				return;
+			}
 			rc = qlt_handle_cmd_for_atio(vha, atio);
-		else
+		} else {
 			rc = qlt_handle_task_mgmt(vha, atio);
+		}
 		if (unlikely(rc != 0)) {
 			if (rc == -ESRCH) {
 #if 1 /* With TERM EXCHANGE some FC cards refuse to boot */
@@ -4369,6 +4644,12 @@ static void qlt_response_pkt(struct scsi_qla_host *vha, response_t *pkt)
 			break;
 		}
 
+		rc = qlt_chk_qfull_thresh_hold(vha, atio);
+		if (rc != 0) {
+			tgt->irq_cmd_count--;
+			return;
+		}
+
 		rc = qlt_handle_cmd_for_atio(vha, atio);
 		if (unlikely(rc != 0)) {
 			if (rc == -ESRCH) {
@@ -4906,6 +5187,10 @@ int qlt_remove_target(struct qla_hw_data *ha, struct scsi_qla_host *vha)
 		qlt_release(vha->vha_tgt.qla_tgt);
 		return 0;
 	}
+
+	/* free left over qfull cmds */
+	qlt_init_term_exchange(vha);
+
 	mutex_lock(&qla_tgt_mutex);
 	list_del(&vha->vha_tgt.qla_tgt->tgt_list_entry);
 	mutex_unlock(&qla_tgt_mutex);
diff --git a/drivers/scsi/qla2xxx/qla_target.h b/drivers/scsi/qla2xxx/qla_target.h
index 20e42bdb6b0f..0c768f5e885a 100644
--- a/drivers/scsi/qla2xxx/qla_target.h
+++ b/drivers/scsi/qla2xxx/qla_target.h
@@ -915,6 +915,8 @@ struct qla_tgt_cmd {
 	unsigned int aborted:1; /* Needed in case of SRR */
 	unsigned int write_data_transferred:1;
 	unsigned int ctx_dsd_alloced:1;
+	unsigned int q_full:1;
+	unsigned int term_exchg:1;
 
 	struct scatterlist *sg;	/* cmd data buffer SG vector */
 	int sg_cnt;		/* SG segments count */
@@ -928,6 +930,7 @@ struct qla_tgt_cmd {
 	uint16_t loop_id;	/* to save extra sess dereferences */
 	struct qla_tgt *tgt;	/* to save extra sess dereferences */
 	struct scsi_qla_host *vha;
+	struct list_head cmd_list;
 
 	struct atio_from_isp atio;
 	/* t10dif */
@@ -1091,5 +1094,6 @@ extern int qlt_stop_phase1(struct qla_tgt *);
 extern void qlt_stop_phase2(struct qla_tgt *);
 extern irqreturn_t qla83xx_msix_atio_q(int, void *);
 extern void qlt_83xx_iospace_config(struct qla_hw_data *);
+extern int qlt_free_qfull_cmds(struct scsi_qla_host *);
 
 #endif /* __QLA_TARGET_H */