[SRU][Xenial][PATCH 1/2] net/mlx4_core: Use cq quota in SRIOV when creating completion EQs

[Joseph Salisbury]

From: Jack Morgenstein <jackm at dev.mellanox.co.il>

BugLink: http://bugs.launchpad.net/bugs/1667527

When creating EQs to handle CQ completion events for the PF
or for VFs, we create enough EQE entries to handle completions
for the max number of CQs that can use that EQ.

When SRIOV is activated, the max number of CQs a VF (or the PF) can
obtain is its CQ quota (determined by the Hypervisor resource tracker).
Therefore, when creating an EQ, the number of EQE entries that the VF
should request for that EQ is the CQ quota value (and not the total
number of CQs available in the FW).

Under SRIOV, the PF, also must use its CQ quota, because
the resource tracker also controls how many CQs the PF can obtain.

Using the FW total CQs instead of the CQ quota when creating EQs resulted
wasting MTT entries, due to allocating more EQEs than were needed.

Fixes: 5a0d0a6161ae ("mlx4: Structures and init/teardown for VF resource quotas")
Signed-off-by: Jack Morgenstein <jackm at dev.mellanox.co.il>
Reported-by: Dexuan Ciu <decui at microsoft.com>
(cherry picked from linux-next commit 6ed63d845e7866ff1a0eac9f0fa554fdf2c64e1d)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>

---
 drivers/net/ethernet/mellanox/mlx4/eq.c   | 5 ++---
 drivers/net/ethernet/mellanox/mlx4/main.c | 3 ++-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/eq.c b/drivers/net/ethernet/mellanox/mlx4/eq.c
index ad6240e..64bf2d3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx4/eq.c
@@ -1235,9 +1235,8 @@ int mlx4_init_eq_table(struct mlx4_dev *dev)
 					mlx4_warn(dev, "Failed adding irq rmap\n");
 			}
 #endif
-			err = mlx4_create_eq(dev, dev->caps.num_cqs -
-						  dev->caps.reserved_cqs +
-						  MLX4_NUM_SPARE_EQE,
+			err = mlx4_create_eq(dev, dev->quotas.cq +
+					     MLX4_NUM_SPARE_EQE,
 					     (dev->flags & MLX4_FLAG_MSI_X) ?
 					     i + 1 - !!(i > MLX4_EQ_ASYNC) : 0,
 					     eq);
diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index b0cff8a..58ea7d5 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3343,6 +3343,8 @@ slave_start:
 			goto err_disable_msix;
 	}
 
+	mlx4_init_quotas(dev);
+
 	err = mlx4_setup_hca(dev);
 	if (err == -EBUSY && (dev->flags & MLX4_FLAG_MSI_X) &&
 	    !mlx4_is_mfunc(dev)) {
@@ -3355,7 +3357,6 @@ slave_start:
 	if (err)
 		goto err_steer;
 
-	mlx4_init_quotas(dev);
 	/* When PF resources are ready arm its comm channel to enable
 	 * getting commands
 	 */
-- 
2.7.4