[SCSI] bnx2i: update CQ arming algorith for 5771x chipsets
Only affects 5771x (10G chipsets) devices
This is an optimized CQ arming algoritm which takes into account the
number of outstanding tasks
Signed-off-by: Anil Veerabhadrappa <anilgv@broadcom.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/bnx2i/bnx2i.h b/drivers/scsi/bnx2i/bnx2i.h
index 2b973f3..6cf9dc3 100644
--- a/drivers/scsi/bnx2i/bnx2i.h
+++ b/drivers/scsi/bnx2i/bnx2i.h
@@ -684,6 +684,7 @@
extern u64 iscsi_error_mask;
extern unsigned int en_tcp_dack;
extern unsigned int event_coal_div;
+extern unsigned int event_coal_min;
extern struct scsi_transport_template *bnx2i_scsi_xport_template;
extern struct iscsi_transport bnx2i_iscsi_transport;
diff --git a/drivers/scsi/bnx2i/bnx2i_hwi.c b/drivers/scsi/bnx2i/bnx2i_hwi.c
index 5c8d763..bb69a14 100644
--- a/drivers/scsi/bnx2i/bnx2i_hwi.c
+++ b/drivers/scsi/bnx2i/bnx2i_hwi.c
@@ -133,20 +133,38 @@
{
struct bnx2i_5771x_cq_db *cq_db;
u16 cq_index;
+ u16 next_index;
+ u32 num_active_cmds;
+
+ /* Coalesce CQ entries only on 10G devices */
if (!test_bit(BNX2I_NX2_DEV_57710, &ep->hba->cnic_dev_type))
return;
+ /* Do not update CQ DB multiple times before firmware writes
+ * '0xFFFF' to CQDB->SQN field. Deviation may cause spurious
+ * interrupts and other unwanted results
+ */
+ cq_db = (struct bnx2i_5771x_cq_db *) ep->qp.cq_pgtbl_virt;
+ if (cq_db->sqn[0] && cq_db->sqn[0] != 0xFFFF)
+ return;
+
if (action == CNIC_ARM_CQE) {
- cq_index = ep->qp.cqe_exp_seq_sn +
- ep->num_active_cmds / event_coal_div;
- cq_index %= (ep->qp.cqe_size * 2 + 1);
- if (!cq_index) {
+ num_active_cmds = ep->num_active_cmds;
+ if (num_active_cmds <= event_coal_min)
+ next_index = 1;
+ else
+ next_index = event_coal_min +
+ (num_active_cmds - event_coal_min) / event_coal_div;
+ if (!next_index)
+ next_index = 1;
+ cq_index = ep->qp.cqe_exp_seq_sn + next_index - 1;
+ if (cq_index > ep->qp.cqe_size * 2)
+ cq_index -= ep->qp.cqe_size * 2;
+ if (!cq_index)
cq_index = 1;
- cq_db = (struct bnx2i_5771x_cq_db *)
- ep->qp.cq_pgtbl_virt;
- cq_db->sqn[0] = cq_index;
- }
+
+ cq_db->sqn[0] = cq_index;
}
}
diff --git a/drivers/scsi/bnx2i/bnx2i_init.c b/drivers/scsi/bnx2i/bnx2i_init.c
index 0307f85..465241d 100644
--- a/drivers/scsi/bnx2i/bnx2i_init.c
+++ b/drivers/scsi/bnx2i/bnx2i_init.c
@@ -32,6 +32,10 @@
static DEFINE_MUTEX(bnx2i_dev_lock);
+unsigned int event_coal_min = 24;
+module_param(event_coal_min, int, 0664);
+MODULE_PARM_DESC(event_coal_min, "Event Coalescing Minimum Commands");
+
unsigned int event_coal_div = 1;
module_param(event_coal_div, int, 0664);
MODULE_PARM_DESC(event_coal_div, "Event Coalescing Divide Factor");