[PATCH 4.12 22/99] net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Huy Nguyen <huyn@xxxxxxxxxxxx>


[ Upstream commit ca3d89a3ebe79367bd41b6b8ba37664478ae2dba ]

enable_4k_uar module parameter was added in patch cited below to
address the backward compatibility issue in SRIOV when the VM has
system's PAGE_SIZE uar implementation and the Hypervisor has 4k uar
implementation.

The above compatibility issue does not exist in the non SRIOV case.
In this patch, we always enable 4k uar implementation if SRIOV
is not enabled on mlx4's supported cards.

Fixes: 76e39ccf9c36 ("net/mlx4_core: Fix backward compatibility on VFs")
Signed-off-by: Huy Nguyen <huyn@xxxxxxxxxxxx>
Reviewed-by: Daniel Jurgens <danielj@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx4/main.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -430,7 +430,7 @@ static int mlx4_dev_cap(struct mlx4_dev
 		/* Virtual PCI function needs to determine UAR page size from
 		 * firmware. Only master PCI function can set the uar page size
 		 */
-		if (enable_4k_uar)
+		if (enable_4k_uar || !dev->persist->num_vfs)
 			dev->uar_page_shift = DEFAULT_UAR_PAGE_SHIFT;
 		else
 			dev->uar_page_shift = PAGE_SHIFT;
@@ -2275,7 +2275,7 @@ static int mlx4_init_hca(struct mlx4_dev
 
 		dev->caps.max_fmr_maps = (1 << (32 - ilog2(dev->caps.num_mpts))) - 1;
 
-		if (enable_4k_uar) {
+		if (enable_4k_uar || !dev->persist->num_vfs) {
 			init_hca.log_uar_sz = ilog2(dev->caps.num_uars) +
 						    PAGE_SHIFT - DEFAULT_UAR_PAGE_SHIFT;
 			init_hca.uar_page_sz = DEFAULT_UAR_PAGE_SHIFT - 12;