net/mlx4_core: Flexible (asymmetric) allocation of EQs and MSI-X vectors for PF/VFs

Previously, the driver queried the firmware in order to get the number
of supported EQs. Under SRIOV, since this was done before the driver
notified the firmware how many VFs it actually needs, the firmware had
to take into account a worst case scenario and always allocated four EQs
per VF, where one was used for events while the others were used for completions.

Now, when the firmware supports the asymmetric allocation scheme, denoted
by exposing num_sys_eqs > 0 (--> MLX4_DEV_CAP_FLAG2_SYS_EQS), we use the
QUERY_FUNC command to query the firmware before enabling SRIOV. Thus we
can get more EQs and MSI-X vectors per function.

Moreover, when running in the new firmware/driver mode, the limitation
that the number of EQs should be a power of two is lifted.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index 3d9bff00f24a..1c560eb870ad 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -189,7 +189,8 @@ enum {
         MLX4_DEV_CAP_FLAG2_EQE_STRIDE           = 1LL <<  13,
         MLX4_DEV_CAP_FLAG2_ETH_PROT_CTRL        = 1LL <<  14,
         MLX4_DEV_CAP_FLAG2_ETH_BACKPL_AN_REP    = 1LL <<  15,
-        MLX4_DEV_CAP_FLAG2_CONFIG_DEV           = 1LL <<  16
+        MLX4_DEV_CAP_FLAG2_CONFIG_DEV           = 1LL <<  16,
+        MLX4_DEV_CAP_FLAG2_SYS_EQS              = 1LL <<  17
 };
 
 enum {
@@ -443,6 +444,7 @@ struct mlx4_caps {
         int                     num_cqs;
         int                     max_cqes;
         int                     reserved_cqs;
+        int                     num_sys_eqs;
         int                     num_eqs;
         int                     reserved_eqs;
         int                     num_comp_vectors;