net/mlx4_core: Add basic support for QP max-rate limiting

Add the low-level device commands and definitions used for QP max-rate limiting.

This is done through the following elements:

  - read rate-limit device caps in QUERY_DEV_CAP: number of different
    rates and the min/max rates in Kbs/Mbs/Gbs units

  - enhance the QP context struct to contain rate limit units and value

  - allow to do run time rate-limit setting to QPs through the
    update-qp firmware command

  - QP rate-limiting is disallowed for VFs

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h
index 1cc5482..4550c67 100644
--- a/include/linux/mlx4/device.h
+++ b/include/linux/mlx4/device.h
@@ -205,6 +205,7 @@
 	MLX4_DEV_CAP_FLAG2_RECOVERABLE_ERROR_EVENT = 1LL << 20,
 	MLX4_DEV_CAP_FLAG2_PORT_REMAP		= 1LL <<  21,
 	MLX4_DEV_CAP_FLAG2_QCN			= 1LL <<  22,
+	MLX4_DEV_CAP_FLAG2_QP_RATE_LIMIT	= 1LL <<  23
 };
 
 enum {
@@ -450,6 +451,21 @@
 	MLX4_MODULE_ID_QSFP28           = 0x11,
 };
 
+enum { /* rl */
+	MLX4_QP_RATE_LIMIT_NONE		= 0,
+	MLX4_QP_RATE_LIMIT_KBS		= 1,
+	MLX4_QP_RATE_LIMIT_MBS		= 2,
+	MLX4_QP_RATE_LIMIT_GBS		= 3
+};
+
+struct mlx4_rate_limit_caps {
+	u16	num_rates; /* Number of different rates */
+	u8	min_unit;
+	u16	min_val;
+	u8	max_unit;
+	u16	max_val;
+};
+
 static inline u64 mlx4_fw_ver(u64 major, u64 minor, u64 subminor)
 {
 	return (major << 32) | (minor << 16) | subminor;
@@ -565,6 +581,7 @@
 	u32			dmfs_high_rate_qpn_base;
 	u32			dmfs_high_rate_qpn_range;
 	u32			vf_caps;
+	struct mlx4_rate_limit_caps rl_caps;
 };
 
 struct mlx4_buf_list {