Merge branch 'cxgb4-next'

Hariprasad Shenai says:

====================
Doorbell drop Avoidance Bug fix for iw_cxgb4

This patch series provides fixes for Chelsio T4/T5 adapters
related to DB Drop avoidance and other small fix related to keepalive on
iw-cxgb4.

The patches series is created against David Miller's 'net-next' tree.
And includes patches on cxgb4 and iw_cxgb4 driver.

We would like to request this patch series to get merged via David Miller's
'net-next' tree.

We have included all the maintainers of respective drivers. Kindly review the
change and let us know in case of any review comments.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/infiniband/hw/cxgb4/cm.c

@@ -1647,6 +1647,15 @@ static inline int act_open_has_tid(int status)
 	       status != CPL_ERR_ARP_MISS;
 }
 
+/* Returns whether a CPL status conveys negative advice.
+ */
+static int is_neg_adv(unsigned int status)
+{
+	return status == CPL_ERR_RTX_NEG_ADVICE ||
+	       status == CPL_ERR_PERSIST_NEG_ADVICE ||
+	       status == CPL_ERR_KEEPALV_NEG_ADVICE;
+}
+
 #define ACT_OPEN_RETRY_COUNT 2
 
 static int import_ep(struct c4iw_ep *ep, int iptype, __u8 *peer_ip,
@@ -1835,7 +1844,7 @@ static int act_open_rpl(struct c4iw_dev *dev, struct sk_buff *skb)
 	PDBG("%s ep %p atid %u status %u errno %d\n", __func__, ep, atid,
 	     status, status2errno(status));
 
-	if (status == CPL_ERR_RTX_NEG_ADVICE) {
+	if (is_neg_adv(status)) {
 		printk(KERN_WARNING MOD "Connection problems for atid %u\n",
 			atid);
 		return 0;
@@ -2265,15 +2274,6 @@ static int peer_close(struct c4iw_dev *dev, struct sk_buff *skb)
 	return 0;
 }
 
-/*
- * Returns whether an ABORT_REQ_RSS message is a negative advice.
- */
-static int is_neg_adv_abort(unsigned int status)
-{
-	return status == CPL_ERR_RTX_NEG_ADVICE ||
-	       status == CPL_ERR_PERSIST_NEG_ADVICE;
-}
-
 static int peer_abort(struct c4iw_dev *dev, struct sk_buff *skb)
 {
 	struct cpl_abort_req_rss *req = cplhdr(skb);
@@ -2287,7 +2287,7 @@ static int peer_abort(struct c4iw_dev *dev, struct sk_buff *skb)
 	unsigned int tid = GET_TID(req);
 
 	ep = lookup_tid(t, tid);
-	if (is_neg_adv_abort(req->status)) {
+	if (is_neg_adv(req->status)) {
 		PDBG("%s neg_adv_abort ep %p tid %u\n", __func__, ep,
 		     ep->hwtid);
 		return 0;
@@ -3570,7 +3570,7 @@ static int peer_abort_intr(struct c4iw_dev *dev, struct sk_buff *skb)
 		kfree_skb(skb);
 		return 0;
 	}
-	if (is_neg_adv_abort(req->status)) {
+	if (is_neg_adv(req->status)) {
 		PDBG("%s neg_adv_abort ep %p tid %u\n", __func__, ep,
 		     ep->hwtid);
 		kfree_skb(skb);

drivers/infiniband/hw/cxgb4/device.c

@@ -64,6 +64,10 @@ struct uld_ctx {
 static LIST_HEAD(uld_ctx_list);
 static DEFINE_MUTEX(dev_mutex);
 
+#define DB_FC_RESUME_SIZE 64
+#define DB_FC_RESUME_DELAY 1
+#define DB_FC_DRAIN_THRESH 0
+
 static struct dentry *c4iw_debugfs_root;
 
 struct c4iw_debugfs_data {
@@ -282,7 +286,7 @@ static const struct file_operations stag_debugfs_fops = {
 	.llseek  = default_llseek,
 };
 
-static char *db_state_str[] = {"NORMAL", "FLOW_CONTROL", "RECOVERY"};
+static char *db_state_str[] = {"NORMAL", "FLOW_CONTROL", "RECOVERY", "STOPPED"};
 
 static int stats_show(struct seq_file *seq, void *v)
 {
@@ -311,9 +315,10 @@ static int stats_show(struct seq_file *seq, void *v)
 	seq_printf(seq, "  DB FULL: %10llu\n", dev->rdev.stats.db_full);
 	seq_printf(seq, " DB EMPTY: %10llu\n", dev->rdev.stats.db_empty);
 	seq_printf(seq, "  DB DROP: %10llu\n", dev->rdev.stats.db_drop);
-	seq_printf(seq, " DB State: %s Transitions %llu\n",
+	seq_printf(seq, " DB State: %s Transitions %llu FC Interruptions %llu\n",
 		   db_state_str[dev->db_state],
-		   dev->rdev.stats.db_state_transitions);
+		   dev->rdev.stats.db_state_transitions,
+		   dev->rdev.stats.db_fc_interruptions);
 	seq_printf(seq, "TCAM_FULL: %10llu\n", dev->rdev.stats.tcam_full);
 	seq_printf(seq, "ACT_OFLD_CONN_FAILS: %10llu\n",
 		   dev->rdev.stats.act_ofld_conn_fails);
@@ -643,6 +648,12 @@ static int c4iw_rdev_open(struct c4iw_rdev *rdev)
 		printk(KERN_ERR MOD "error %d initializing ocqp pool\n", err);
 		goto err4;
 	}
+	rdev->status_page = (struct t4_dev_status_page *)
+			    __get_free_page(GFP_KERNEL);
+	if (!rdev->status_page) {
+		pr_err(MOD "error allocating status page\n");
+		goto err4;
+	}
 	return 0;
 err4:
 	c4iw_rqtpool_destroy(rdev);
@@ -656,6 +667,7 @@ static int c4iw_rdev_open(struct c4iw_rdev *rdev)
 
 static void c4iw_rdev_close(struct c4iw_rdev *rdev)
 {
+	free_page((unsigned long)rdev->status_page);
 	c4iw_pblpool_destroy(rdev);
 	c4iw_rqtpool_destroy(rdev);
 	c4iw_destroy_resource(&rdev->resource);
@@ -703,18 +715,6 @@ static struct c4iw_dev *c4iw_alloc(const struct cxgb4_lld_info *infop)
 		pr_info("%s: On-Chip Queues not supported on this device.\n",
 			pci_name(infop->pdev));
 
-	if (!is_t4(infop->adapter_type)) {
-		if (!allow_db_fc_on_t5) {
-			db_fc_threshold = 100000;
-			pr_info("DB Flow Control Disabled.\n");
-		}
-
-		if (!allow_db_coalescing_on_t5) {
-			db_coalescing_threshold = -1;
-			pr_info("DB Coalescing Disabled.\n");
-		}
-	}
-
 	devp = (struct c4iw_dev *)ib_alloc_device(sizeof(*devp));
 	if (!devp) {
 		printk(KERN_ERR MOD "Cannot allocate ib device\n");
@@ -749,6 +749,7 @@ static struct c4iw_dev *c4iw_alloc(const struct cxgb4_lld_info *infop)
 	spin_lock_init(&devp->lock);
 	mutex_init(&devp->rdev.stats.lock);
 	mutex_init(&devp->db_mutex);
+	INIT_LIST_HEAD(&devp->db_fc_list);
 
 	if (c4iw_debugfs_root) {
 		devp->debugfs_root = debugfs_create_dir(
@@ -977,13 +978,16 @@ static int disable_qp_db(int id, void *p, void *data)
 
 static void stop_queues(struct uld_ctx *ctx)
 {
-	spin_lock_irq(&ctx->dev->lock);
-	if (ctx->dev->db_state == NORMAL) {
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctx->dev->lock, flags);
 	ctx->dev->rdev.stats.db_state_transitions++;
-		ctx->dev->db_state = FLOW_CONTROL;
+	ctx->dev->db_state = STOPPED;
+	if (ctx->dev->rdev.flags & T4_STATUS_PAGE_DISABLED)
 		idr_for_each(&ctx->dev->qpidr, disable_qp_db, NULL);
-	}
-	spin_unlock_irq(&ctx->dev->lock);
+	else
+		ctx->dev->rdev.status_page->db_off = 1;
+	spin_unlock_irqrestore(&ctx->dev->lock, flags);
 }
 
 static int enable_qp_db(int id, void *p, void *data)
@@ -994,15 +998,70 @@ static int enable_qp_db(int id, void *p, void *data)
 	return 0;
 }
 
+static void resume_rc_qp(struct c4iw_qp *qp)
+{
+	spin_lock(&qp->lock);
+	t4_ring_sq_db(&qp->wq, qp->wq.sq.wq_pidx_inc);
+	qp->wq.sq.wq_pidx_inc = 0;
+	t4_ring_rq_db(&qp->wq, qp->wq.rq.wq_pidx_inc);
+	qp->wq.rq.wq_pidx_inc = 0;
+	spin_unlock(&qp->lock);
+}
+
+static void resume_a_chunk(struct uld_ctx *ctx)
+{
+	int i;
+	struct c4iw_qp *qp;
+
+	for (i = 0; i < DB_FC_RESUME_SIZE; i++) {
+		qp = list_first_entry(&ctx->dev->db_fc_list, struct c4iw_qp,
+				      db_fc_entry);
+		list_del_init(&qp->db_fc_entry);
+		resume_rc_qp(qp);
+		if (list_empty(&ctx->dev->db_fc_list))
+			break;
+	}
+}
+
 static void resume_queues(struct uld_ctx *ctx)
 {
 	spin_lock_irq(&ctx->dev->lock);
-	if (ctx->dev->qpcnt <= db_fc_threshold &&
-	    ctx->dev->db_state == FLOW_CONTROL) {
+	if (ctx->dev->db_state != STOPPED)
+		goto out;
+	ctx->dev->db_state = FLOW_CONTROL;
+	while (1) {
+		if (list_empty(&ctx->dev->db_fc_list)) {
+			WARN_ON(ctx->dev->db_state != FLOW_CONTROL);
 			ctx->dev->db_state = NORMAL;
 			ctx->dev->rdev.stats.db_state_transitions++;
-		idr_for_each(&ctx->dev->qpidr, enable_qp_db, NULL);
+			if (ctx->dev->rdev.flags & T4_STATUS_PAGE_DISABLED) {
+				idr_for_each(&ctx->dev->qpidr, enable_qp_db,
+					     NULL);
+			} else {
+				ctx->dev->rdev.status_page->db_off = 0;
+			}
+			break;
+		} else {
+			if (cxgb4_dbfifo_count(ctx->dev->rdev.lldi.ports[0], 1)
+			    < (ctx->dev->rdev.lldi.dbfifo_int_thresh <<
+			       DB_FC_DRAIN_THRESH)) {
+				resume_a_chunk(ctx);
+			}
+			if (!list_empty(&ctx->dev->db_fc_list)) {
+				spin_unlock_irq(&ctx->dev->lock);
+				if (DB_FC_RESUME_DELAY) {
+					set_current_state(TASK_UNINTERRUPTIBLE);
+					schedule_timeout(DB_FC_RESUME_DELAY);
+				}
+				spin_lock_irq(&ctx->dev->lock);
+				if (ctx->dev->db_state != FLOW_CONTROL)
+					break;
+			}
 		}
+	}
+out:
+	if (ctx->dev->db_state != NORMAL)
+		ctx->dev->rdev.stats.db_fc_interruptions++;
 	spin_unlock_irq(&ctx->dev->lock);
 }
 
@@ -1028,12 +1087,12 @@ static int count_qps(int id, void *p, void *data)
 	return 0;
 }
 
-static void deref_qps(struct qp_list qp_list)
+static void deref_qps(struct qp_list *qp_list)
 {
 	int idx;
 
-	for (idx = 0; idx < qp_list.idx; idx++)
-		c4iw_qp_rem_ref(&qp_list.qps[idx]->ibqp);
+	for (idx = 0; idx < qp_list->idx; idx++)
+		c4iw_qp_rem_ref(&qp_list->qps[idx]->ibqp);
 }
 
 static void recover_lost_dbs(struct uld_ctx *ctx, struct qp_list *qp_list)
@@ -1044,17 +1103,22 @@ static void recover_lost_dbs(struct uld_ctx *ctx, struct qp_list *qp_list)
 	for (idx = 0; idx < qp_list->idx; idx++) {
 		struct c4iw_qp *qp = qp_list->qps[idx];
 
+		spin_lock_irq(&qp->rhp->lock);
+		spin_lock(&qp->lock);
 		ret = cxgb4_sync_txq_pidx(qp->rhp->rdev.lldi.ports[0],
 					  qp->wq.sq.qid,
 					  t4_sq_host_wq_pidx(&qp->wq),
 					  t4_sq_wq_size(&qp->wq));
 		if (ret) {
-			printk(KERN_ERR MOD "%s: Fatal error - "
+			pr_err(KERN_ERR MOD "%s: Fatal error - "
 			       "DB overflow recovery failed - "
 			       "error syncing SQ qid %u\n",
 			       pci_name(ctx->lldi.pdev), qp->wq.sq.qid);
+			spin_unlock(&qp->lock);
+			spin_unlock_irq(&qp->rhp->lock);
 			return;
 		}
+		qp->wq.sq.wq_pidx_inc = 0;
 
 		ret = cxgb4_sync_txq_pidx(qp->rhp->rdev.lldi.ports[0],
 					  qp->wq.rq.qid,
@@ -1062,12 +1126,17 @@ static void recover_lost_dbs(struct uld_ctx *ctx, struct qp_list *qp_list)
 					  t4_rq_wq_size(&qp->wq));
 
 		if (ret) {
-			printk(KERN_ERR MOD "%s: Fatal error - "
+			pr_err(KERN_ERR MOD "%s: Fatal error - "
 			       "DB overflow recovery failed - "
 			       "error syncing RQ qid %u\n",
 			       pci_name(ctx->lldi.pdev), qp->wq.rq.qid);
+			spin_unlock(&qp->lock);
+			spin_unlock_irq(&qp->rhp->lock);
 			return;
 		}
+		qp->wq.rq.wq_pidx_inc = 0;
+		spin_unlock(&qp->lock);
+		spin_unlock_irq(&qp->rhp->lock);
 
 		/* Wait for the dbfifo to drain */
 		while (cxgb4_dbfifo_count(qp->rhp->rdev.lldi.ports[0], 1) > 0) {
@@ -1083,36 +1152,22 @@ static void recover_queues(struct uld_ctx *ctx)
 	struct qp_list qp_list;
 	int ret;
 
-	/* lock out kernel db ringers */
-	mutex_lock(&ctx->dev->db_mutex);
-
-	/* put all queues in to recovery mode */
-	spin_lock_irq(&ctx->dev->lock);
-	ctx->dev->db_state = RECOVERY;
-	ctx->dev->rdev.stats.db_state_transitions++;
-	idr_for_each(&ctx->dev->qpidr, disable_qp_db, NULL);
-	spin_unlock_irq(&ctx->dev->lock);
-
 	/* slow everybody down */
 	set_current_state(TASK_UNINTERRUPTIBLE);
 	schedule_timeout(usecs_to_jiffies(1000));
 
-	/* Wait for the dbfifo to completely drain. */
-	while (cxgb4_dbfifo_count(ctx->dev->rdev.lldi.ports[0], 1) > 0) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		schedule_timeout(usecs_to_jiffies(10));
-	}
-
 	/* flush the SGE contexts */
 	ret = cxgb4_flush_eq_cache(ctx->dev->rdev.lldi.ports[0]);
 	if (ret) {
 		printk(KERN_ERR MOD "%s: Fatal error - DB overflow recovery failed\n",
 		       pci_name(ctx->lldi.pdev));
-		goto out;
+		return;
 	}
 
 	/* Count active queues so we can build a list of queues to recover */
 	spin_lock_irq(&ctx->dev->lock);
+	WARN_ON(ctx->dev->db_state != STOPPED);
+	ctx->dev->db_state = RECOVERY;
 	idr_for_each(&ctx->dev->qpidr, count_qps, &count);
 
 	qp_list.qps = kzalloc(count * sizeof *qp_list.qps, GFP_ATOMIC);
@@ -1120,7 +1175,7 @@ static void recover_queues(struct uld_ctx *ctx)
 		printk(KERN_ERR MOD "%s: Fatal error - DB overflow recovery failed\n",
 		       pci_name(ctx->lldi.pdev));
 		spin_unlock_irq(&ctx->dev->lock);
-		goto out;
+		return;
 	}
 	qp_list.idx = 0;
 
@@ -1133,29 +1188,13 @@ static void recover_queues(struct uld_ctx *ctx)
 	recover_lost_dbs(ctx, &qp_list);
 
 	/* we're almost done!  deref the qps and clean up */
-	deref_qps(qp_list);
+	deref_qps(&qp_list);
 	kfree(qp_list.qps);
 
-	/* Wait for the dbfifo to completely drain again */
-	while (cxgb4_dbfifo_count(ctx->dev->rdev.lldi.ports[0], 1) > 0) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		schedule_timeout(usecs_to_jiffies(10));
-	}
-
-	/* resume the queues */
 	spin_lock_irq(&ctx->dev->lock);
-	if (ctx->dev->qpcnt > db_fc_threshold)
-		ctx->dev->db_state = FLOW_CONTROL;
-	else {
-		ctx->dev->db_state = NORMAL;
-		idr_for_each(&ctx->dev->qpidr, enable_qp_db, NULL);
-	}
-	ctx->dev->rdev.stats.db_state_transitions++;
+	WARN_ON(ctx->dev->db_state != RECOVERY);
+	ctx->dev->db_state = STOPPED;
 	spin_unlock_irq(&ctx->dev->lock);
-
-out:
-	/* start up kernel db ringers again */
-	mutex_unlock(&ctx->dev->db_mutex);
 }
 
 static int c4iw_uld_control(void *handle, enum cxgb4_control control, ...)
@@ -1165,9 +1204,7 @@ static int c4iw_uld_control(void *handle, enum cxgb4_control control, ...)
 	switch (control) {
 	case CXGB4_CONTROL_DB_FULL:
 		stop_queues(ctx);
-		mutex_lock(&ctx->dev->rdev.stats.lock);
 		ctx->dev->rdev.stats.db_full++;
-		mutex_unlock(&ctx->dev->rdev.stats.lock);
 		break;
 	case CXGB4_CONTROL_DB_EMPTY:
 		resume_queues(ctx);

drivers/infiniband/hw/cxgb4/iw_cxgb4.h

@@ -109,6 +109,7 @@ struct c4iw_dev_ucontext {
 
 enum c4iw_rdev_flags {
 	T4_FATAL_ERROR = (1<<0),
+	T4_STATUS_PAGE_DISABLED = (1<<1),
 };
 
 struct c4iw_stat {
@@ -130,6 +131,7 @@ struct c4iw_stats {
 	u64  db_empty;
 	u64  db_drop;
 	u64  db_state_transitions;
+	u64  db_fc_interruptions;
 	u64  tcam_full;
 	u64  act_ofld_conn_fails;
 	u64  pas_ofld_conn_fails;
@@ -150,6 +152,7 @@ struct c4iw_rdev {
 	unsigned long oc_mw_pa;
 	void __iomem *oc_mw_kva;
 	struct c4iw_stats stats;
+	struct t4_dev_status_page *status_page;
 };
 
 static inline int c4iw_fatal_error(struct c4iw_rdev *rdev)
@@ -211,7 +214,8 @@ static inline int c4iw_wait_for_reply(struct c4iw_rdev *rdev,
 enum db_state {
 	NORMAL = 0,
 	FLOW_CONTROL = 1,
-	RECOVERY = 2
+	RECOVERY = 2,
+	STOPPED = 3
 };
 
 struct c4iw_dev {
@@ -225,10 +229,10 @@ struct c4iw_dev {
 	struct mutex db_mutex;
 	struct dentry *debugfs_root;
 	enum db_state db_state;
-	int qpcnt;
 	struct idr hwtid_idr;
 	struct idr atid_idr;
 	struct idr stid_idr;
+	struct list_head db_fc_list;
 };
 
 static inline struct c4iw_dev *to_c4iw_dev(struct ib_device *ibdev)
@@ -432,6 +436,7 @@ struct c4iw_qp_attributes {
 
 struct c4iw_qp {
 	struct ib_qp ibqp;
+	struct list_head db_fc_entry;
 	struct c4iw_dev *rhp;
 	struct c4iw_ep *ep;
 	struct c4iw_qp_attributes attr;

drivers/infiniband/hw/cxgb4/provider.c

@@ -106,15 +106,54 @@ static struct ib_ucontext *c4iw_alloc_ucontext(struct ib_device *ibdev,
 {
 	struct c4iw_ucontext *context;
 	struct c4iw_dev *rhp = to_c4iw_dev(ibdev);
+	static int warned;
+	struct c4iw_alloc_ucontext_resp uresp;
+	int ret = 0;
+	struct c4iw_mm_entry *mm = NULL;
 
 	PDBG("%s ibdev %p\n", __func__, ibdev);
 	context = kzalloc(sizeof(*context), GFP_KERNEL);
-	if (!context)
-		return ERR_PTR(-ENOMEM);
+	if (!context) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
 	c4iw_init_dev_ucontext(&rhp->rdev, &context->uctx);
 	INIT_LIST_HEAD(&context->mmaps);
 	spin_lock_init(&context->mmap_lock);
+
+	if (udata->outlen < sizeof(uresp)) {
+		if (!warned++)
+			pr_err(MOD "Warning - downlevel libcxgb4 (non-fatal), device status page disabled.");
+		rhp->rdev.flags |= T4_STATUS_PAGE_DISABLED;
+	} else {
+		mm = kmalloc(sizeof(*mm), GFP_KERNEL);
+		if (!mm)
+			goto err_free;
+
+		uresp.status_page_size = PAGE_SIZE;
+
+		spin_lock(&context->mmap_lock);
+		uresp.status_page_key = context->key;
+		context->key += PAGE_SIZE;
+		spin_unlock(&context->mmap_lock);
+
+		ret = ib_copy_to_udata(udata, &uresp, sizeof(uresp));
+		if (ret)
+			goto err_mm;
+
+		mm->key = uresp.status_page_key;
+		mm->addr = virt_to_phys(rhp->rdev.status_page);
+		mm->len = PAGE_SIZE;
+		insert_mmap(context, mm);
+	}
 	return &context->ibucontext;
+err_mm:
+	kfree(mm);
+err_free:
+	kfree(context);
+err:
+	return ERR_PTR(ret);
 }
 
 static int c4iw_mmap(struct ib_ucontext *context, struct vm_area_struct *vma)

drivers/infiniband/hw/cxgb4/qp.c

@@ -638,6 +638,46 @@ void c4iw_qp_rem_ref(struct ib_qp *qp)
 		wake_up(&(to_c4iw_qp(qp)->wait));
 }
 
+static void add_to_fc_list(struct list_head *head, struct list_head *entry)
+{
+	if (list_empty(entry))
+		list_add_tail(entry, head);
+}
+
+static int ring_kernel_sq_db(struct c4iw_qp *qhp, u16 inc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&qhp->rhp->lock, flags);
+	spin_lock(&qhp->lock);
+	if (qhp->rhp->db_state == NORMAL) {
+		t4_ring_sq_db(&qhp->wq, inc);
+	} else {
+		add_to_fc_list(&qhp->rhp->db_fc_list, &qhp->db_fc_entry);
+		qhp->wq.sq.wq_pidx_inc += inc;
+	}
+	spin_unlock(&qhp->lock);
+	spin_unlock_irqrestore(&qhp->rhp->lock, flags);
+	return 0;
+}
+
+static int ring_kernel_rq_db(struct c4iw_qp *qhp, u16 inc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&qhp->rhp->lock, flags);
+	spin_lock(&qhp->lock);
+	if (qhp->rhp->db_state == NORMAL) {
+		t4_ring_rq_db(&qhp->wq, inc);
+	} else {
+		add_to_fc_list(&qhp->rhp->db_fc_list, &qhp->db_fc_entry);
+		qhp->wq.rq.wq_pidx_inc += inc;
+	}
+	spin_unlock(&qhp->lock);
+	spin_unlock_irqrestore(&qhp->rhp->lock, flags);
+	return 0;
+}
+
 int c4iw_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 		   struct ib_send_wr **bad_wr)
 {
@@ -750,9 +790,13 @@ int c4iw_post_send(struct ib_qp *ibqp, struct ib_send_wr *wr,
 		t4_sq_produce(&qhp->wq, len16);
 		idx += DIV_ROUND_UP(len16*16, T4_EQ_ENTRY_SIZE);
 	}
-	if (t4_wq_db_enabled(&qhp->wq))
+	if (!qhp->rhp->rdev.status_page->db_off) {
 		t4_ring_sq_db(&qhp->wq, idx);
 		spin_unlock_irqrestore(&qhp->lock, flag);
+	} else {
+		spin_unlock_irqrestore(&qhp->lock, flag);
+		ring_kernel_sq_db(qhp, idx);
+	}
 	return err;
 }
 
@@ -812,9 +856,13 @@ int c4iw_post_receive(struct ib_qp *ibqp, struct ib_recv_wr *wr,
 		wr = wr->next;
 		num_wrs--;
 	}
-	if (t4_wq_db_enabled(&qhp->wq))
+	if (!qhp->rhp->rdev.status_page->db_off) {
 		t4_ring_rq_db(&qhp->wq, idx);
 		spin_unlock_irqrestore(&qhp->lock, flag);
+	} else {
+		spin_unlock_irqrestore(&qhp->lock, flag);
+		ring_kernel_rq_db(qhp, idx);
+	}
 	return err;
 }
 
@@ -1200,35 +1248,6 @@ static int rdma_init(struct c4iw_dev *rhp, struct c4iw_qp *qhp)
 	return ret;
 }
 
-/*
- * Called by the library when the qp has user dbs disabled due to
- * a DB_FULL condition.  This function will single-thread all user
- * DB rings to avoid overflowing the hw db-fifo.
- */
-static int ring_kernel_db(struct c4iw_qp *qhp, u32 qid, u16 inc)
-{
-	int delay = db_delay_usecs;
-
-	mutex_lock(&qhp->rhp->db_mutex);
-	do {
-
-		/*
-		 * The interrupt threshold is dbfifo_int_thresh << 6. So
-		 * make sure we don't cross that and generate an interrupt.
-		 */
-		if (cxgb4_dbfifo_count(qhp->rhp->rdev.lldi.ports[0], 1) <
-		    (qhp->rhp->rdev.lldi.dbfifo_int_thresh << 5)) {
-			writel(QID(qid) | PIDX(inc), qhp->wq.db);
-			break;
-		}
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		schedule_timeout(usecs_to_jiffies(delay));
-		delay = min(delay << 1, 2000);
-	} while (1);
-	mutex_unlock(&qhp->rhp->db_mutex);
-	return 0;
-}
-
 int c4iw_modify_qp(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
 		   enum c4iw_qp_attr_mask mask,
 		   struct c4iw_qp_attributes *attrs,
@@ -1278,11 +1297,11 @@ int c4iw_modify_qp(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
 	}
 
 	if (mask & C4IW_QP_ATTR_SQ_DB) {
-		ret = ring_kernel_db(qhp, qhp->wq.sq.qid, attrs->sq_db_inc);
+		ret = ring_kernel_sq_db(qhp, attrs->sq_db_inc);
 		goto out;
 	}
 	if (mask & C4IW_QP_ATTR_RQ_DB) {
-		ret = ring_kernel_db(qhp, qhp->wq.rq.qid, attrs->rq_db_inc);
+		ret = ring_kernel_rq_db(qhp, attrs->rq_db_inc);
 		goto out;
 	}
 
@@ -1465,14 +1484,6 @@ int c4iw_modify_qp(struct c4iw_dev *rhp, struct c4iw_qp *qhp,
 	return ret;
 }
 
-static int enable_qp_db(int id, void *p, void *data)
-{
-	struct c4iw_qp *qp = p;
-
-	t4_enable_wq_db(&qp->wq);
-	return 0;
-}
-
 int c4iw_destroy_qp(struct ib_qp *ib_qp)
 {
 	struct c4iw_dev *rhp;
@@ -1490,22 +1501,15 @@ int c4iw_destroy_qp(struct ib_qp *ib_qp)
 		c4iw_modify_qp(rhp, qhp, C4IW_QP_ATTR_NEXT_STATE, &attrs, 0);
 	wait_event(qhp->wait, !qhp->ep);
 
-	spin_lock_irq(&rhp->lock);
-	remove_handle_nolock(rhp, &rhp->qpidr, qhp->wq.sq.qid);
-	rhp->qpcnt--;
-	BUG_ON(rhp->qpcnt < 0);
-	if (rhp->qpcnt <= db_fc_threshold && rhp->db_state == FLOW_CONTROL) {
-		rhp->rdev.stats.db_state_transitions++;
-		rhp->db_state = NORMAL;
-		idr_for_each(&rhp->qpidr, enable_qp_db, NULL);
-	}
-	if (db_coalescing_threshold >= 0)
-		if (rhp->qpcnt <= db_coalescing_threshold)
-			cxgb4_enable_db_coalescing(rhp->rdev.lldi.ports[0]);
-	spin_unlock_irq(&rhp->lock);
+	remove_handle(rhp, &rhp->qpidr, qhp->wq.sq.qid);
 	atomic_dec(&qhp->refcnt);
 	wait_event(qhp->wait, !atomic_read(&qhp->refcnt));
 
+	spin_lock_irq(&rhp->lock);
+	if (!list_empty(&qhp->db_fc_entry))
+		list_del_init(&qhp->db_fc_entry);
+	spin_unlock_irq(&rhp->lock);
+
 	ucontext = ib_qp->uobject ?
 		   to_c4iw_ucontext(ib_qp->uobject->context) : NULL;
 	destroy_qp(&rhp->rdev, &qhp->wq,
@@ -1516,14 +1520,6 @@ int c4iw_destroy_qp(struct ib_qp *ib_qp)
 	return 0;
 }
 
-static int disable_qp_db(int id, void *p, void *data)
-{
-	struct c4iw_qp *qp = p;
-
-	t4_disable_wq_db(&qp->wq);
-	return 0;
-}
-
 struct ib_qp *c4iw_create_qp(struct ib_pd *pd, struct ib_qp_init_attr *attrs,
 			     struct ib_udata *udata)
 {
@@ -1610,20 +1606,7 @@ struct ib_qp *c4iw_create_qp(struct ib_pd *pd, struct ib_qp_init_attr *attrs,
 	init_waitqueue_head(&qhp->wait);
 	atomic_set(&qhp->refcnt, 1);
 
-	spin_lock_irq(&rhp->lock);
-	if (rhp->db_state != NORMAL)
-		t4_disable_wq_db(&qhp->wq);
-	rhp->qpcnt++;
-	if (rhp->qpcnt > db_fc_threshold && rhp->db_state == NORMAL) {
-		rhp->rdev.stats.db_state_transitions++;
-		rhp->db_state = FLOW_CONTROL;
-		idr_for_each(&rhp->qpidr, disable_qp_db, NULL);
-	}
-	if (db_coalescing_threshold >= 0)
-		if (rhp->qpcnt > db_coalescing_threshold)
-			cxgb4_disable_db_coalescing(rhp->rdev.lldi.ports[0]);
-	ret = insert_handle_nolock(rhp, &rhp->qpidr, qhp, qhp->wq.sq.qid);
-	spin_unlock_irq(&rhp->lock);
+	ret = insert_handle(rhp, &rhp->qpidr, qhp, qhp->wq.sq.qid);
 	if (ret)
 		goto err2;
 
@@ -1709,6 +1692,7 @@ struct ib_qp *c4iw_create_qp(struct ib_pd *pd, struct ib_qp_init_attr *attrs,
 	}
 	qhp->ibqp.qp_num = qhp->wq.sq.qid;
 	init_timer(&(qhp->timer));
+	INIT_LIST_HEAD(&qhp->db_fc_entry);
 	PDBG("%s qhp %p sq_num_entries %d, rq_num_entries %d qpid 0x%0x\n",
 	     __func__, qhp, qhp->attr.sq_num_entries, qhp->attr.rq_num_entries,
 	     qhp->wq.sq.qid);

drivers/infiniband/hw/cxgb4/t4.h

@@ -300,6 +300,7 @@ struct t4_sq {
 	u16 cidx;
 	u16 pidx;
 	u16 wq_pidx;
+	u16 wq_pidx_inc;
 	u16 flags;
 	short flush_cidx;
 };
@@ -324,6 +325,7 @@ struct t4_rq {
 	u16 cidx;
 	u16 pidx;
 	u16 wq_pidx;
+	u16 wq_pidx_inc;
 };
 
 struct t4_wq {
@@ -609,3 +611,7 @@ static inline void t4_set_cq_in_error(struct t4_cq *cq)
 	((struct t4_status_page *)&cq->queue[cq->size])->qp_err = 1;
 }
 #endif
+
+struct t4_dev_status_page {
+	u8 db_off;
+};

drivers/infiniband/hw/cxgb4/user.h

@@ -70,4 +70,9 @@ struct c4iw_create_qp_resp {
 	__u32 qid_mask;
 	__u32 flags;
 };
+
+struct c4iw_alloc_ucontext_resp {
+	__u64 status_page_key;
+	__u32 status_page_size;
+};
 #endif

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -500,6 +500,7 @@ struct sge_txq {
 	spinlock_t db_lock;
 	int db_disabled;
 	unsigned short db_pidx;
+	unsigned short db_pidx_inc;
 	u64 udb;
 };
 

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c

@@ -3578,14 +3578,25 @@ static void drain_db_fifo(struct adapter *adap, int usecs)
 
 static void disable_txq_db(struct sge_txq *q)
 {
-	spin_lock_irq(&q->db_lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&q->db_lock, flags);
 	q->db_disabled = 1;
-	spin_unlock_irq(&q->db_lock);
+	spin_unlock_irqrestore(&q->db_lock, flags);
 }
 
-static void enable_txq_db(struct sge_txq *q)
+static void enable_txq_db(struct adapter *adap, struct sge_txq *q)
 {
 	spin_lock_irq(&q->db_lock);
+	if (q->db_pidx_inc) {
+		/* Make sure that all writes to the TX descriptors
+		 * are committed before we tell HW about them.
+		 */
+		wmb();
+		t4_write_reg(adap, MYPF_REG(SGE_PF_KDOORBELL),
+			     QID(q->cntxt_id) | PIDX(q->db_pidx_inc));
+		q->db_pidx_inc = 0;
+	}
 	q->db_disabled = 0;
 	spin_unlock_irq(&q->db_lock);
 }
@@ -3607,11 +3618,32 @@ static void enable_dbs(struct adapter *adap)
 	int i;
 
 	for_each_ethrxq(&adap->sge, i)
-		enable_txq_db(&adap->sge.ethtxq[i].q);
+		enable_txq_db(adap, &adap->sge.ethtxq[i].q);
 	for_each_ofldrxq(&adap->sge, i)
-		enable_txq_db(&adap->sge.ofldtxq[i].q);
+		enable_txq_db(adap, &adap->sge.ofldtxq[i].q);
 	for_each_port(adap, i)
-		enable_txq_db(&adap->sge.ctrlq[i].q);
+		enable_txq_db(adap, &adap->sge.ctrlq[i].q);
+}
+
+static void notify_rdma_uld(struct adapter *adap, enum cxgb4_control cmd)
+{
+	if (adap->uld_handle[CXGB4_ULD_RDMA])
+		ulds[CXGB4_ULD_RDMA].control(adap->uld_handle[CXGB4_ULD_RDMA],
+				cmd);
+}
+
+static void process_db_full(struct work_struct *work)
+{
+	struct adapter *adap;
+
+	adap = container_of(work, struct adapter, db_full_task);
+
+	drain_db_fifo(adap, dbfifo_drain_delay);
+	enable_dbs(adap);
+	notify_rdma_uld(adap, CXGB4_CONTROL_DB_EMPTY);
+	t4_set_reg_field(adap, SGE_INT_ENABLE3,
+			 DBFIFO_HP_INT | DBFIFO_LP_INT,
+			 DBFIFO_HP_INT | DBFIFO_LP_INT);
 }
 
 static void sync_txq_pidx(struct adapter *adap, struct sge_txq *q)
@@ -3619,7 +3651,7 @@ static void sync_txq_pidx(struct adapter *adap, struct sge_txq *q)
 	u16 hw_pidx, hw_cidx;
 	int ret;
 
-	spin_lock_bh(&q->db_lock);
+	spin_lock_irq(&q->db_lock);
 	ret = read_eq_indices(adap, (u16)q->cntxt_id, &hw_pidx, &hw_cidx);
 	if (ret)
 		goto out;
@@ -3636,7 +3668,8 @@ static void sync_txq_pidx(struct adapter *adap, struct sge_txq *q)
 	}
 out:
 	q->db_disabled = 0;
-	spin_unlock_bh(&q->db_lock);
+	q->db_pidx_inc = 0;
+	spin_unlock_irq(&q->db_lock);
 	if (ret)
 		CH_WARN(adap, "DB drop recovery failed.\n");
 }
@@ -3652,29 +3685,6 @@ static void recover_all_queues(struct adapter *adap)
 		sync_txq_pidx(adap, &adap->sge.ctrlq[i].q);
 }
 
-static void notify_rdma_uld(struct adapter *adap, enum cxgb4_control cmd)
-{
-	mutex_lock(&uld_mutex);
-	if (adap->uld_handle[CXGB4_ULD_RDMA])
-		ulds[CXGB4_ULD_RDMA].control(adap->uld_handle[CXGB4_ULD_RDMA],
-				cmd);
-	mutex_unlock(&uld_mutex);
-}
-
-static void process_db_full(struct work_struct *work)
-{
-	struct adapter *adap;
-
-	adap = container_of(work, struct adapter, db_full_task);
-
-	notify_rdma_uld(adap, CXGB4_CONTROL_DB_FULL);
-	drain_db_fifo(adap, dbfifo_drain_delay);
-	t4_set_reg_field(adap, SGE_INT_ENABLE3,
-			 DBFIFO_HP_INT | DBFIFO_LP_INT,
-			 DBFIFO_HP_INT | DBFIFO_LP_INT);
-	notify_rdma_uld(adap, CXGB4_CONTROL_DB_EMPTY);
-}
-
 static void process_db_drop(struct work_struct *work)
 {
 	struct adapter *adap;
@@ -3682,11 +3692,13 @@ static void process_db_drop(struct work_struct *work)
 	adap = container_of(work, struct adapter, db_drop_task);
 
 	if (is_t4(adap->params.chip)) {
-		disable_dbs(adap);
+		drain_db_fifo(adap, dbfifo_drain_delay);
 		notify_rdma_uld(adap, CXGB4_CONTROL_DB_DROP);
-		drain_db_fifo(adap, 1);
+		drain_db_fifo(adap, dbfifo_drain_delay);
 		recover_all_queues(adap);
+		drain_db_fifo(adap, dbfifo_drain_delay);
 		enable_dbs(adap);
+		notify_rdma_uld(adap, CXGB4_CONTROL_DB_EMPTY);
 	} else {
 		u32 dropped_db = t4_read_reg(adap, 0x010ac);
 		u16 qid = (dropped_db >> 15) & 0x1ffff;
@@ -3727,6 +3739,8 @@ static void process_db_drop(struct work_struct *work)
 void t4_db_full(struct adapter *adap)
 {
 	if (is_t4(adap->params.chip)) {
+		disable_dbs(adap);
+		notify_rdma_uld(adap, CXGB4_CONTROL_DB_FULL);
 		t4_set_reg_field(adap, SGE_INT_ENABLE3,
 				 DBFIFO_HP_INT | DBFIFO_LP_INT, 0);
 		queue_work(workq, &adap->db_full_task);
@@ -3735,7 +3749,10 @@ void t4_db_full(struct adapter *adap)
 
 void t4_db_dropped(struct adapter *adap)
 {
-	if (is_t4(adap->params.chip))
+	if (is_t4(adap->params.chip)) {
+		disable_dbs(adap);
+		notify_rdma_uld(adap, CXGB4_CONTROL_DB_FULL);
+	}
 	queue_work(workq, &adap->db_drop_task);
 }
 

drivers/net/ethernet/chelsio/cxgb4/sge.c

@@ -860,9 +860,10 @@ static void cxgb_pio_copy(u64 __iomem *dst, u64 *src)
 static inline void ring_tx_db(struct adapter *adap, struct sge_txq *q, int n)
 {
 	unsigned int *wr, index;
+	unsigned long flags;
 
 	wmb();            /* write descriptors before telling HW */
-	spin_lock(&q->db_lock);
+	spin_lock_irqsave(&q->db_lock, flags);
 	if (!q->db_disabled) {
 		if (is_t4(adap->params.chip)) {
 			t4_write_reg(adap, MYPF_REG(SGE_PF_KDOORBELL),
@@ -878,9 +879,10 @@ static inline void ring_tx_db(struct adapter *adap, struct sge_txq *q, int n)
 				writel(n,  adap->bar2 + q->udb + 8);
 			wmb();
 		}
-	}
+	} else
+		q->db_pidx_inc += n;
 	q->db_pidx = q->pidx;
-	spin_unlock(&q->db_lock);
+	spin_unlock_irqrestore(&q->db_lock, flags);
 }
 
 /**

drivers/net/ethernet/chelsio/cxgb4/t4_msg.h

@@ -116,6 +116,7 @@ enum CPL_error {
 	CPL_ERR_KEEPALIVE_TIMEDOUT = 34,
 	CPL_ERR_RTX_NEG_ADVICE     = 35,
 	CPL_ERR_PERSIST_NEG_ADVICE = 36,
+	CPL_ERR_KEEPALV_NEG_ADVICE = 37,
 	CPL_ERR_ABORT_FAILED       = 42,
 	CPL_ERR_IWARP_FLM          = 50,
 };