[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>
This commit is contained in:
Anil Veerabhadrappa 2009-12-07 11:40:18 -08:00 committed by James Bottomley
parent f8c9abe797
commit 8776193bc3
3 changed files with 31 additions and 8 deletions

View file

@ -684,6 +684,7 @@ extern unsigned int error_mask1, error_mask2;
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;

View file

@ -133,20 +133,38 @@ void bnx2i_arm_cq_event_coalescing(struct bnx2i_endpoint *ep, u8 action)
{
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;
}
}

View file

@ -32,6 +32,10 @@ MODULE_VERSION(DRV_MODULE_VERSION);
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");