NTB: Disable interrupts and poll under high load (e8aeb60c) · Commits · jan.koester / Linux

drivers/ntb/ntb_hw.c

+37 −5

Original line number	Original line	Diff line number	Diff line
	@@ -141,6 +141,24 @@ void ntb_unregister_event_callback(struct ntb_device *ndev)
	ndev->event_cb = NULL;		ndev->event_cb = NULL;
	}		}

			static void ntb_irq_work(unsigned long data)
			{
			struct ntb_db_cb db_cb = (struct ntb_db_cb )data;
			int rc;

			rc = db_cb->callback(db_cb->data, db_cb->db_num);
			if (rc)
			tasklet_schedule(&db_cb->irq_work);
			else {
			struct ntb_device *ndev = db_cb->ndev;
			unsigned long mask;

			mask = readw(ndev->reg_ofs.ldb_mask);
			clear_bit(db_cb->db_num * ndev->bits_per_vector, &mask);
			writew(mask, ndev->reg_ofs.ldb_mask);
			}
			}

	/**		/**
	* ntb_register_db_callback() - register a callback for doorbell interrupt		* ntb_register_db_callback() - register a callback for doorbell interrupt
	* @ndev: pointer to ntb_device instance		* @ndev: pointer to ntb_device instance
	@@ -155,7 +173,7 @@ void ntb_unregister_event_callback(struct ntb_device *ndev)
	* RETURNS: An appropriate -ERRNO error value on error, or zero for success.		* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
	*/		*/
	int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,		int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,
	void data, void (func)(void *data, int db_num))		void data, int (func)(void *data, int db_num))
	{		{
	unsigned long mask;		unsigned long mask;

	@@ -166,6 +184,10 @@ int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,

	ndev->db_cb[idx].callback = func;		ndev->db_cb[idx].callback = func;
	ndev->db_cb[idx].data = data;		ndev->db_cb[idx].data = data;
			ndev->db_cb[idx].ndev = ndev;

			tasklet_init(&ndev->db_cb[idx].irq_work, ntb_irq_work,
			(unsigned long) &ndev->db_cb[idx]);

	/* unmask interrupt */		/* unmask interrupt */
	mask = readw(ndev->reg_ofs.ldb_mask);		mask = readw(ndev->reg_ofs.ldb_mask);
	@@ -194,6 +216,8 @@ void ntb_unregister_db_callback(struct ntb_device *ndev, unsigned int idx)
	set_bit(idx * ndev->bits_per_vector, &mask);		set_bit(idx * ndev->bits_per_vector, &mask);
	writew(mask, ndev->reg_ofs.ldb_mask);		writew(mask, ndev->reg_ofs.ldb_mask);

			tasklet_disable(&ndev->db_cb[idx].irq_work);

	ndev->db_cb[idx].callback = NULL;		ndev->db_cb[idx].callback = NULL;
	}		}

	@@ -955,12 +979,16 @@ static irqreturn_t bwd_callback_msix_irq(int irq, void *data)
	{		{
	struct ntb_db_cb *db_cb = data;		struct ntb_db_cb *db_cb = data;
	struct ntb_device *ndev = db_cb->ndev;		struct ntb_device *ndev = db_cb->ndev;
			unsigned long mask;

	dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for DB %d\n", irq,		dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for DB %d\n", irq,
	db_cb->db_num);		db_cb->db_num);

	if (db_cb->callback)		mask = readw(ndev->reg_ofs.ldb_mask);
	db_cb->callback(db_cb->data, db_cb->db_num);		set_bit(db_cb->db_num * ndev->bits_per_vector, &mask);
			writew(mask, ndev->reg_ofs.ldb_mask);

			tasklet_schedule(&db_cb->irq_work);

	/* No need to check for the specific HB irq, any interrupt means		/* No need to check for the specific HB irq, any interrupt means
	* we're connected.		* we're connected.
	@@ -976,12 +1004,16 @@ static irqreturn_t xeon_callback_msix_irq(int irq, void *data)
	{		{
	struct ntb_db_cb *db_cb = data;		struct ntb_db_cb *db_cb = data;
	struct ntb_device *ndev = db_cb->ndev;		struct ntb_device *ndev = db_cb->ndev;
			unsigned long mask;

	dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for DB %d\n", irq,		dev_dbg(&ndev->pdev->dev, "MSI-X irq %d received for DB %d\n", irq,
	db_cb->db_num);		db_cb->db_num);

	if (db_cb->callback)		mask = readw(ndev->reg_ofs.ldb_mask);
	db_cb->callback(db_cb->data, db_cb->db_num);		set_bit(db_cb->db_num * ndev->bits_per_vector, &mask);
			writew(mask, ndev->reg_ofs.ldb_mask);

			tasklet_schedule(&db_cb->irq_work);

	/* On Sandybridge, there are 16 bits in the interrupt register		/* On Sandybridge, there are 16 bits in the interrupt register
	* but only 4 vectors. So, 5 bits are assigned to the first 3		* but only 4 vectors. So, 5 bits are assigned to the first 3

drivers/ntb/ntb_hw.h

+4 −3

Original line number	Original line	Diff line number	Diff line
	@@ -106,10 +106,11 @@ struct ntb_mw {
	};		};

	struct ntb_db_cb {		struct ntb_db_cb {
	void (callback) (void data, int db_num);		int (callback)(void data, int db_num);
	unsigned int db_num;		unsigned int db_num;
	void *data;		void *data;
	struct ntb_device *ndev;		struct ntb_device *ndev;
			struct tasklet_struct irq_work;
	};		};

	struct ntb_device {		struct ntb_device {
	@@ -228,7 +229,7 @@ struct ntb_device ntb_register_transport(struct pci_dev pdev,
	void ntb_unregister_transport(struct ntb_device *ndev);		void ntb_unregister_transport(struct ntb_device *ndev);
	void ntb_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr);		void ntb_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr);
	int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,		int ntb_register_db_callback(struct ntb_device *ndev, unsigned int idx,
	void data, void (db_cb_func) (void *data,		void data, int (db_cb_func)(void *data,
	int db_num));		int db_num));
	void ntb_unregister_db_callback(struct ntb_device *ndev, unsigned int idx);		void ntb_unregister_db_callback(struct ntb_device *ndev, unsigned int idx);
	int ntb_register_event_callback(struct ntb_device *ndev,		int ntb_register_event_callback(struct ntb_device *ndev,

drivers/ntb/ntb_transport.c

+7 −18

Original line number	Original line	Diff line number	Diff line
	@@ -119,7 +119,6 @@ struct ntb_transport_qp {

	void (rx_handler) (struct ntb_transport_qp qp, void *qp_data,		void (rx_handler) (struct ntb_transport_qp qp, void *qp_data,
	void *data, int len);		void *data, int len);
	struct tasklet_struct rx_work;
	struct list_head rx_pend_q;		struct list_head rx_pend_q;
	struct list_head rx_free_q;		struct list_head rx_free_q;
	spinlock_t ntb_rx_pend_q_lock;		spinlock_t ntb_rx_pend_q_lock;
	@@ -1188,11 +1187,14 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
	goto out;		goto out;
	}		}

	static void ntb_transport_rx(unsigned long data)		static int ntb_transport_rxc_db(void *data, int db_num)
	{		{
	struct ntb_transport_qp qp = (struct ntb_transport_qp )data;		struct ntb_transport_qp *qp = data;
	int rc, i;		int rc, i;

			dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",
			__func__, db_num);

	/* Limit the number of packets processed in a single interrupt to		/* Limit the number of packets processed in a single interrupt to
	* provide fairness to others		* provide fairness to others
	*/		*/
	@@ -1204,16 +1206,8 @@ static void ntb_transport_rx(unsigned long data)

	if (qp->dma_chan)		if (qp->dma_chan)
	dma_async_issue_pending(qp->dma_chan);		dma_async_issue_pending(qp->dma_chan);
	}

	static void ntb_transport_rxc_db(void *data, int db_num)
	{
	struct ntb_transport_qp *qp = data;

	dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%s: doorbell %d received\n",		return i;
	__func__, db_num);

	tasklet_schedule(&qp->rx_work);
	}		}

	static void ntb_tx_copy_callback(void *data)		static void ntb_tx_copy_callback(void *data)
	@@ -1446,19 +1440,15 @@ ntb_transport_create_queue(void data, struct pci_dev pdev,
	&qp->tx_free_q);		&qp->tx_free_q);
	}		}

	tasklet_init(&qp->rx_work, ntb_transport_rx, (unsigned long) qp);

	rc = ntb_register_db_callback(qp->ndev, free_queue, qp,		rc = ntb_register_db_callback(qp->ndev, free_queue, qp,
	ntb_transport_rxc_db);		ntb_transport_rxc_db);
	if (rc)		if (rc)
	goto err3;		goto err2;

	dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);		dev_info(&pdev->dev, "NTB Transport QP %d created\n", qp->qp_num);

	return qp;		return qp;

	err3:
	tasklet_disable(&qp->rx_work);
	err2:		err2:
	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))		while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))
	kfree(entry);		kfree(entry);
	@@ -1505,7 +1495,6 @@ void ntb_transport_free_queue(struct ntb_transport_qp *qp)
	}		}

	ntb_unregister_db_callback(qp->ndev, qp->qp_num);		ntb_unregister_db_callback(qp->ndev, qp->qp_num);
	tasklet_disable(&qp->rx_work);

	cancel_delayed_work_sync(&qp->link_work);		cancel_delayed_work_sync(&qp->link_work);