Patch "IB/hfi1: Fix softlockup issue" has been added to the 4.9-stable tree

@@ -6379,18 +6379,17 @@ static void lcb_shutdown(struct hfi1_dev
  *
  * The expectation is that the caller of this routine would have taken
  * care of properly transitioning the link into the correct state.
+ * NOTE: the caller needs to acquire the dd->dc8051_lock lock
+ *       before calling this function.
  */
-static void dc_shutdown(struct hfi1_devdata *dd)
+static void _dc_shutdown(struct hfi1_devdata *dd)
 {
-	unsigned long flags;
+	lockdep_assert_held(&dd->dc8051_lock);
 
-	spin_lock_irqsave(&dd->dc8051_lock, flags);
-	if (dd->dc_shutdown) {
-		spin_unlock_irqrestore(&dd->dc8051_lock, flags);
+	if (dd->dc_shutdown)
 		return;
-	}
+
 	dd->dc_shutdown = 1;
-	spin_unlock_irqrestore(&dd->dc8051_lock, flags);
 	/* Shutdown the LCB */
 	lcb_shutdown(dd, 1);
 	/*

@@ -6401,35 +6400,45 @@ static void dc_shutdown(struct hfi1_devd
 	write_csr(dd, DC_DC8051_CFG_RST, 0x1);
 }
 
+static void dc_shutdown(struct hfi1_devdata *dd)
+{
+	mutex_lock(&dd->dc8051_lock);
+	_dc_shutdown(dd);
+	mutex_unlock(&dd->dc8051_lock);
+}
+
 /*
  * Calling this after the DC has been brought out of reset should not
  * do any damage.
+ * NOTE: the caller needs to acquire the dd->dc8051_lock lock
+ *       before calling this function.
  */
-static void dc_start(struct hfi1_devdata *dd)
+static void _dc_start(struct hfi1_devdata *dd)
 {
-	unsigned long flags;
-	int ret;
+	lockdep_assert_held(&dd->dc8051_lock);
 
-	spin_lock_irqsave(&dd->dc8051_lock, flags);
 	if (!dd->dc_shutdown)
-		goto done;
-	spin_unlock_irqrestore(&dd->dc8051_lock, flags);
+		return;
+
 	/* Take the 8051 out of reset */
 	write_csr(dd, DC_DC8051_CFG_RST, 0ull);
 	/* Wait until 8051 is ready */
-	ret = wait_fm_ready(dd, TIMEOUT_8051_START);
-	if (ret) {
+	if (wait_fm_ready(dd, TIMEOUT_8051_START))
 		dd_dev_err(dd, "%s: timeout starting 8051 firmware\n",
 			   __func__);
-	}
+
 	/* Take away reset for LCB and RX FPE (set in lcb_shutdown). */
 	write_csr(dd, DCC_CFG_RESET, 0x10);
 	/* lcb_shutdown() with abort=1 does not restore these */
 	write_csr(dd, DC_LCB_ERR_EN, dd->lcb_err_en);
-	spin_lock_irqsave(&dd->dc8051_lock, flags);
 	dd->dc_shutdown = 0;
-done:
-	spin_unlock_irqrestore(&dd->dc8051_lock, flags);
+}
+
+static void dc_start(struct hfi1_devdata *dd)
+{
+	mutex_lock(&dd->dc8051_lock);
+	_dc_start(dd);
+	mutex_unlock(&dd->dc8051_lock);
 }
 
 /*

@@ -8418,16 +8427,11 @@ static int do_8051_command(
 {
 	u64 reg, completed;
 	int return_code;
-	unsigned long flags;
 	unsigned long timeout;
 
 	hfi1_cdbg(DC8051, "type %d, data 0x%012llx", type, in_data);
 
-	/*
-	 * Alternative to holding the lock for a long time:
-	 * - keep busy wait - have other users bounce off
-	 */
-	spin_lock_irqsave(&dd->dc8051_lock, flags);
+	mutex_lock(&dd->dc8051_lock);
 
 	/* We can't send any commands to the 8051 if it's in reset */
 	if (dd->dc_shutdown) {

@@ -8453,10 +8457,8 @@ static int do_8051_command(
 			return_code = -ENXIO;
 			goto fail;
 		}
-		spin_unlock_irqrestore(&dd->dc8051_lock, flags);
-		dc_shutdown(dd);
-		dc_start(dd);
-		spin_lock_irqsave(&dd->dc8051_lock, flags);
+		_dc_shutdown(dd);
+		_dc_start(dd);
 	}
 
 	/*

@@ -8534,8 +8536,7 @@ static int do_8051_command(
 	write_csr(dd, DC_DC8051_CFG_HOST_CMD_0, 0);
 
 fail:
-	spin_unlock_irqrestore(&dd->dc8051_lock, flags);
-
+	mutex_unlock(&dd->dc8051_lock);
 	return return_code;
 }
 

@@ -11849,6 +11850,10 @@ static void free_cntrs(struct hfi1_devda
 	dd->scntrs = NULL;
 	kfree(dd->cntrnames);
 	dd->cntrnames = NULL;
+	if (dd->update_cntr_wq) {
+		destroy_workqueue(dd->update_cntr_wq);
+		dd->update_cntr_wq = NULL;
+	}
 }
 
 static u64 read_dev_port_cntr(struct hfi1_devdata *dd, struct cntr_entry *entry,

@@ -12004,7 +12009,7 @@ u64 write_port_cntr(struct hfi1_pportdat
 	return write_dev_port_cntr(ppd->dd, entry, sval, ppd, vl, data);
 }
 
-static void update_synth_timer(unsigned long opaque)
+static void do_update_synth_timer(struct work_struct *work)
 {
 	u64 cur_tx;
 	u64 cur_rx;

@@ -12013,8 +12018,8 @@ static void update_synth_timer(unsigned
 	int i, j, vl;
 	struct hfi1_pportdata *ppd;
 	struct cntr_entry *entry;
-
-	struct hfi1_devdata *dd = (struct hfi1_devdata *)opaque;
+	struct hfi1_devdata *dd = container_of(work, struct hfi1_devdata,
+					       update_cntr_work);
 
 	/*
 	 * Rather than keep beating on the CSRs pick a minimal set that we can

@@ -12097,7 +12102,13 @@ static void update_synth_timer(unsigned
 	} else {
 		hfi1_cdbg(CNTR, "[%d] No update necessary", dd->unit);
 	}
+}
+
+static void update_synth_timer(unsigned long opaque)
+{
+	struct hfi1_devdata *dd = (struct hfi1_devdata *)opaque;
 
+	queue_work(dd->update_cntr_wq, &dd->update_cntr_work);
 	mod_timer(&dd->synth_stats_timer, jiffies + HZ * SYNTH_CNT_TIME);
 }
 

@@ -12333,6 +12344,13 @@ static int init_cntrs(struct hfi1_devdat
 	if (init_cpu_counters(dd))
 		goto bail;
 
+	dd->update_cntr_wq = alloc_ordered_workqueue("hfi1_update_cntr_%d",
+						     WQ_MEM_RECLAIM, dd->unit);
+	if (!dd->update_cntr_wq)
+		goto bail;
+
+	INIT_WORK(&dd->update_cntr_work, do_update_synth_timer);
+
 	mod_timer(&dd->synth_stats_timer, jiffies + HZ * SYNTH_CNT_TIME);
 	return 0;
 bail:

@@ -475,7 +475,7 @@ struct rvt_sge_state;
 #define HFI1_PART_ENFORCE_OUT	0x2
 
 /* how often we check for synthetic counter wrap around */
-#define SYNTH_CNT_TIME 2
+#define SYNTH_CNT_TIME 3
 
 /* Counter flags */
 #define CNTR_NORMAL		0x0 /* Normal counters, just read register */

@@ -929,8 +929,9 @@ struct hfi1_devdata {
 	spinlock_t rcvctrl_lock; /* protect changes to RcvCtrl */
 	/* around rcd and (user ctxts) ctxt_cnt use (intr vs free) */
 	spinlock_t uctxt_lock; /* rcd and user context changes */
-	/* exclusive access to 8051 */
-	spinlock_t dc8051_lock;
+	struct mutex dc8051_lock; /* exclusive access to 8051 */
+	struct workqueue_struct *update_cntr_wq;
+	struct work_struct update_cntr_work;
 	/* exclusive access to 8051 memory */
 	spinlock_t dc8051_memlock;
 	int dc8051_timed_out;	/* remember if the 8051 timed out */

@@ -1078,11 +1078,11 @@ struct hfi1_devdata *hfi1_alloc_devdata(
 	spin_lock_init(&dd->uctxt_lock);
 	spin_lock_init(&dd->hfi1_diag_trans_lock);
 	spin_lock_init(&dd->sc_init_lock);
-	spin_lock_init(&dd->dc8051_lock);
 	spin_lock_init(&dd->dc8051_memlock);
 	seqlock_init(&dd->sc2vl_lock);
 	spin_lock_init(&dd->sde_map_lock);
 	spin_lock_init(&dd->pio_map_lock);
+	mutex_init(&dd->dc8051_lock);
 	init_waitqueue_head(&dd->event_queue);
 
 	dd->int_counter = alloc_percpu(u64);