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Commit e8aeb60c authored by Jon Mason's avatar Jon Mason
Browse files

NTB: Disable interrupts and poll under high load 



Disable interrupts and poll under high load

Signed-off-by: default avatarJon Mason <jon.mason@intel.com>
parent 78958433

drivers/ntb/ntb_hw.c

+37 −5
Original line number Diff line number Diff line
@@ -141,6 +141,24 @@ void ntb_unregister_event_callback(struct ntb_device *ndev) 
	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

 * @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.

 */

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;
@@ -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].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 */

	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);

	writew(mask, ndev->reg_ofs.ldb_mask);



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



	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_device *ndev = db_cb->ndev;

	unsigned long mask;



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

		db_cb->db_num);



	if (db_cb->callback)

		db_cb->callback(db_cb->data, db_cb->db_num);

	mask = readw(ndev->reg_ofs.ldb_mask);

	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

	 * 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_device *ndev = db_cb->ndev;

	unsigned long mask;



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

		db_cb->db_num);



	if (db_cb->callback)

		db_cb->callback(db_cb->data, db_cb->db_num);

	mask = readw(ndev->reg_ofs.ldb_mask);

	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

	 * but only 4 vectors.  So, 5 bits are assigned to the first 3

drivers/ntb/ntb_hw.h

+4 −3
Original line number Diff line number Diff line
@@ -106,10 +106,11 @@ struct ntb_mw { 
};



struct ntb_db_cb {

	void (*callback) (void *data, int db_num);

	int (*callback)(void *data, int db_num);

	unsigned int db_num;

	void *data;

	struct ntb_device *ndev;

	struct tasklet_struct irq_work;

};



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_set_mw_addr(struct ntb_device *ndev, unsigned int mw, u64 addr);

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));

void ntb_unregister_db_callback(struct ntb_device *ndev, unsigned int idx);

int ntb_register_event_callback(struct ntb_device *ndev,

drivers/ntb/ntb_transport.c

+7 −18
Original line number 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 *data, int len);

	struct tasklet_struct rx_work;

	struct list_head rx_pend_q;

	struct list_head rx_free_q;

	spinlock_t ntb_rx_pend_q_lock;
@@ -1188,11 +1187,14 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp) 
	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;



	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

	 * provide fairness to others

	 */
@@ -1204,16 +1206,8 @@ static void ntb_transport_rx(unsigned long data) 


	if (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",

		__func__, db_num);



	tasklet_schedule(&qp->rx_work);

	return i;

}



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);

	}



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



	rc = ntb_register_db_callback(qp->ndev, free_queue, qp,

				      ntb_transport_rxc_db);

	if (rc)

		goto err3;

		goto err2;



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



	return qp;



err3:

	tasklet_disable(&qp->rx_work);

err2:

	while ((entry = ntb_list_rm(&qp->ntb_tx_free_q_lock, &qp->tx_free_q)))

		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);

	tasklet_disable(&qp->rx_work);



	cancel_delayed_work_sync(&qp->link_work);