From e8aeb60c389c2aa48d345bcf717f8cb7edf67680 Mon Sep 17 00:00:00 2001 From: Jon Mason Date: Thu, 18 Apr 2013 17:59:44 -0700 Subject: [PATCH] NTB: Disable interrupts and poll under high load Disable interrupts and poll under high load Signed-off-by: Jon Mason --- drivers/ntb/ntb_hw.c | 42 ++++++++++++++++++++++++++++++++----- drivers/ntb/ntb_hw.h | 7 ++++--- drivers/ntb/ntb_transport.c | 25 +++++++--------------- 3 files changed, 48 insertions(+), 26 deletions(-) diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c index 80505aeecf9e..170e8e60cdb7 100644 --- a/drivers/ntb/ntb_hw.c +++ b/drivers/ntb/ntb_hw.c @@ -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 diff --git a/drivers/ntb/ntb_hw.h b/drivers/ntb/ntb_hw.h index 0a31cedae7d4..bbdb7edca10c 100644 --- a/drivers/ntb/ntb_hw.h +++ b/drivers/ntb/ntb_hw.h @@ -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 { @@ -228,8 +229,8 @@ 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, - int db_num)); + 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, void (*event_cb_func) (void *handle, diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index 172501d47600..676937bd679c 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -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 @@ err: 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); -- 2.34.1