[PATCH net 1/1] net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled

[PATCH net 1/1] net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled

[Saeed Mahameed]

From: Huy Nguyen <huyn@mellanox.com>

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@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx4/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index 09b9bc17bce9..5fe5cdc51357 100644
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -432,7 +432,7 @@ static int mlx4_dev_cap(struct mlx4_dev *dev, struct mlx4_dev_cap *dev_cap)
 		/* 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;
@@ -2277,7 +2277,7 @@ static int mlx4_init_hca(struct mlx4_dev *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;
-- 
2.13.0

Re: [PATCH net 1/1] net/mlx4_core: Enable 4K UAR if SRIOV module parameter is not enabled

[David Miller]

From: Saeed Mahameed <saeedm@mellanox.com>
Date: Thu, 17 Aug 2017 18:29:52 +0300

> From: Huy Nguyen <huyn@mellanox.com>
> 
> 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@mellanox.com>
> Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Applied and queued up for -stable, thanks.