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authorJon Mason <jon.mason@intel.com>2013-04-18 17:59:44 -0700
committerJon Mason <jon.mason@intel.com>2013-11-20 09:57:34 -0700
commite8aeb60c389c2aa48d345bcf717f8cb7edf67680 (patch)
tree3610f55a47e8f0bc722397ec8063c9a4f4091f9b /drivers/ntb
parent78958433db077b339f3a039890148561086574e4 (diff)
downloadlinux-e8aeb60c389c2aa48d345bcf717f8cb7edf67680.tar.gz
NTB: Disable interrupts and poll under high load
Disable interrupts and poll under high load Signed-off-by: Jon Mason <jon.mason@intel.com>
Diffstat (limited to 'drivers/ntb')
-rw-r--r--drivers/ntb/ntb_hw.c42
-rw-r--r--drivers/ntb/ntb_hw.h7
-rw-r--r--drivers/ntb/ntb_transport.c25
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);