NTB: Disable interrupts and poll under high load
Disable interrupts and poll under high load
Signed-off-by: Jon Mason <jon.mason@intel.com>
diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index 80505ae..170e8e6 100644
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -141,6 +141,24 @@
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 @@
* 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 @@
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 @@
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 @@
{
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 @@
{
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