diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/dcbnl.h b/drivers/net/ethernet/mellanox/mlx5/core/en/dcbnl.h
index 7be6b2d36b60..9976de8b9047 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/dcbnl.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/dcbnl.h
@@ -29,6 +29,7 @@ struct mlx5e_dcbx {
 	bool                       manual_buffer;
 	u32                        cable_len;
 	u32                        xoff;
+	u16                        port_buff_cell_sz;
 };
 
 #define MLX5E_MAX_DSCP (64)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
index ae99fac08b53..673f1c82d381 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
@@ -34,6 +34,7 @@
 int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
 			    struct mlx5e_port_buffer *port_buffer)
 {
+	u16 port_buff_cell_sz = priv->dcbx.port_buff_cell_sz;
 	struct mlx5_core_dev *mdev = priv->mdev;
 	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
 	u32 total_used = 0;
@@ -57,11 +58,11 @@ int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
 		port_buffer->buffer[i].epsb =
 			MLX5_GET(bufferx_reg, buffer, epsb);
 		port_buffer->buffer[i].size =
-			MLX5_GET(bufferx_reg, buffer, size) << MLX5E_BUFFER_CELL_SHIFT;
+			MLX5_GET(bufferx_reg, buffer, size) * port_buff_cell_sz;
 		port_buffer->buffer[i].xon =
-			MLX5_GET(bufferx_reg, buffer, xon_threshold) << MLX5E_BUFFER_CELL_SHIFT;
+			MLX5_GET(bufferx_reg, buffer, xon_threshold) * port_buff_cell_sz;
 		port_buffer->buffer[i].xoff =
-			MLX5_GET(bufferx_reg, buffer, xoff_threshold) << MLX5E_BUFFER_CELL_SHIFT;
+			MLX5_GET(bufferx_reg, buffer, xoff_threshold) * port_buff_cell_sz;
 		total_used += port_buffer->buffer[i].size;
 
 		mlx5e_dbg(HW, priv, "buffer %d: size=%d, xon=%d, xoff=%d, epsb=%d, lossy=%d\n", i,
@@ -73,7 +74,7 @@ int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
 	}
 
 	port_buffer->port_buffer_size =
-		MLX5_GET(pbmc_reg, out, port_buffer_size) << MLX5E_BUFFER_CELL_SHIFT;
+		MLX5_GET(pbmc_reg, out, port_buffer_size) * port_buff_cell_sz;
 	port_buffer->spare_buffer_size =
 		port_buffer->port_buffer_size - total_used;
 
@@ -88,9 +89,9 @@ int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
 static int port_set_buffer(struct mlx5e_priv *priv,
 			   struct mlx5e_port_buffer *port_buffer)
 {
+	u16 port_buff_cell_sz = priv->dcbx.port_buff_cell_sz;
 	struct mlx5_core_dev *mdev = priv->mdev;
 	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
-	void *buffer;
 	void *in;
 	int err;
 	int i;
@@ -104,16 +105,18 @@ static int port_set_buffer(struct mlx5e_priv *priv,
 		goto out;
 
 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
-		buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);
-
-		MLX5_SET(bufferx_reg, buffer, size,
-			 port_buffer->buffer[i].size >> MLX5E_BUFFER_CELL_SHIFT);
-		MLX5_SET(bufferx_reg, buffer, lossy,
-			 port_buffer->buffer[i].lossy);
-		MLX5_SET(bufferx_reg, buffer, xoff_threshold,
-			 port_buffer->buffer[i].xoff >> MLX5E_BUFFER_CELL_SHIFT);
-		MLX5_SET(bufferx_reg, buffer, xon_threshold,
-			 port_buffer->buffer[i].xon >> MLX5E_BUFFER_CELL_SHIFT);
+		void *buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);
+		u64 size = port_buffer->buffer[i].size;
+		u64 xoff = port_buffer->buffer[i].xoff;
+		u64 xon = port_buffer->buffer[i].xon;
+
+		do_div(size, port_buff_cell_sz);
+		do_div(xoff, port_buff_cell_sz);
+		do_div(xon, port_buff_cell_sz);
+		MLX5_SET(bufferx_reg, buffer, size, size);
+		MLX5_SET(bufferx_reg, buffer, lossy, port_buffer->buffer[i].lossy);
+		MLX5_SET(bufferx_reg, buffer, xoff_threshold, xoff);
+		MLX5_SET(bufferx_reg, buffer, xon_threshold, xon);
 	}
 
 	err = mlx5e_port_set_pbmc(mdev, in);
@@ -143,7 +146,7 @@ static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
 }
 
 static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
-				 u32 xoff, unsigned int max_mtu)
+				 u32 xoff, unsigned int max_mtu, u16 port_buff_cell_sz)
 {
 	int i;
 
@@ -155,7 +158,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
 		}
 
 		if (port_buffer->buffer[i].size <
-		    (xoff + max_mtu + (1 << MLX5E_BUFFER_CELL_SHIFT))) {
+		    (xoff + max_mtu + port_buff_cell_sz)) {
 			pr_err("buffer_size[%d]=%d is not enough for lossless buffer\n",
 			       i, port_buffer->buffer[i].size);
 			return -ENOMEM;
@@ -175,6 +178,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
  *	@pfc_en: <input> current pfc configuration
  *	@buffer: <input> current prio to buffer mapping
  *	@xoff:   <input> xoff value
+ *	@port_buff_cell_sz: <input> port buffer cell_size
  *	@port_buffer: <output> port receive buffer configuration
  *	@change: <output>
  *
@@ -189,7 +193,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
  *	sets change to true if buffer configuration was modified.
  */
 static int update_buffer_lossy(unsigned int max_mtu,
-			       u8 pfc_en, u8 *buffer, u32 xoff,
+			       u8 pfc_en, u8 *buffer, u32 xoff, u16 port_buff_cell_sz,
 			       struct mlx5e_port_buffer *port_buffer,
 			       bool *change)
 {
@@ -225,7 +229,7 @@ static int update_buffer_lossy(unsigned int max_mtu,
 	}
 
 	if (changed) {
-		err = update_xoff_threshold(port_buffer, xoff, max_mtu);
+		err = update_xoff_threshold(port_buffer, xoff, max_mtu, port_buff_cell_sz);
 		if (err)
 			return err;
 
@@ -262,6 +266,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 				    u32 *buffer_size,
 				    u8 *prio2buffer)
 {
+	u16 port_buff_cell_sz = priv->dcbx.port_buff_cell_sz;
 	struct mlx5e_port_buffer port_buffer;
 	u32 xoff = calculate_xoff(priv, mtu);
 	bool update_prio2buffer = false;
@@ -282,7 +287,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 
 	if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
 		update_buffer = true;
-		err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
+		err = update_xoff_threshold(&port_buffer, xoff, max_mtu, port_buff_cell_sz);
 		if (err)
 			return err;
 	}
@@ -292,7 +297,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 		if (err)
 			return err;
 
-		err = update_buffer_lossy(max_mtu, pfc->pfc_en, buffer, xoff,
+		err = update_buffer_lossy(max_mtu, pfc->pfc_en, buffer, xoff, port_buff_cell_sz,
 					  &port_buffer, &update_buffer);
 		if (err)
 			return err;
@@ -304,7 +309,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 		if (err)
 			return err;
 
-		err = update_buffer_lossy(max_mtu, curr_pfc_en, prio2buffer,
+		err = update_buffer_lossy(max_mtu, curr_pfc_en, prio2buffer, port_buff_cell_sz,
 					  xoff, &port_buffer, &update_buffer);
 		if (err)
 			return err;
@@ -329,7 +334,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 			return -EINVAL;
 
 		update_buffer = true;
-		err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
+		err = update_xoff_threshold(&port_buffer, xoff, max_mtu, port_buff_cell_sz);
 		if (err)
 			return err;
 	}
@@ -337,7 +342,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 	/* Need to update buffer configuration if xoff value is changed */
 	if (!update_buffer && xoff != priv->dcbx.xoff) {
 		update_buffer = true;
-		err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
+		err = update_xoff_threshold(&port_buffer, xoff, max_mtu, port_buff_cell_sz);
 		if (err)
 			return err;
 	}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.h b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.h
index 34f55b81a0de..80af7a5ac604 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.h
@@ -36,7 +36,6 @@
 #include "port.h"
 
 #define MLX5E_MAX_BUFFER 8
-#define MLX5E_BUFFER_CELL_SHIFT 7
 #define MLX5E_DEFAULT_CABLE_LEN 7 /* 7 meters */
 
 #define MLX5_BUFFER_SUPPORTED(mdev) (MLX5_CAP_GEN(mdev, pcam_reg) && \
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
index bc102d094bbd..d20243d6a032 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_dcbnl.c
@@ -1217,6 +1217,24 @@ static int mlx5e_trust_initialize(struct mlx5e_priv *priv)
 	return 0;
 }
 
+#define MLX5E_BUFFER_CELL_SHIFT 7
+
+static u16 mlx5e_query_port_buffers_cell_size(struct mlx5e_priv *priv)
+{
+	struct mlx5_core_dev *mdev = priv->mdev;
+	u32 out[MLX5_ST_SZ_DW(sbcam_reg)] = {};
+	u32 in[MLX5_ST_SZ_DW(sbcam_reg)] = {};
+
+	if (!MLX5_CAP_GEN(mdev, sbcam_reg))
+		return (1 << MLX5E_BUFFER_CELL_SHIFT);
+
+	if (mlx5_core_access_reg(mdev, in, sizeof(in), out, sizeof(out),
+				 MLX5_REG_SBCAM, 0, 0))
+		return (1 << MLX5E_BUFFER_CELL_SHIFT);
+
+	return MLX5_GET(sbcam_reg, out, cap_cell_size);
+}
+
 void mlx5e_dcbnl_initialize(struct mlx5e_priv *priv)
 {
 	struct mlx5e_dcbx *dcbx = &priv->dcbx;
@@ -1234,6 +1252,7 @@ void mlx5e_dcbnl_initialize(struct mlx5e_priv *priv)
 	if (priv->dcbx.mode == MLX5E_DCBX_PARAM_VER_OPER_HOST)
 		priv->dcbx.cap |= DCB_CAP_DCBX_HOST;
 
+	priv->dcbx.port_buff_cell_sz = mlx5e_query_port_buffers_cell_size(priv);
 	priv->dcbx.manual_buffer = false;
 	priv->dcbx.cable_len = MLX5E_DEFAULT_CABLE_LEN;
 
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 13c0e4556eda..1e6ca716635a 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -147,6 +147,7 @@ enum {
 	MLX5_REG_MCDA		 = 0x9063,
 	MLX5_REG_MCAM		 = 0x907f,
 	MLX5_REG_MIRC		 = 0x9162,
+	MLX5_REG_SBCAM		 = 0xB01F,
 	MLX5_REG_RESOURCE_DUMP   = 0xC000,
 };
 
diff --git a/include/linux/mlx5/mlx5_ifc.h b/include/linux/mlx5/mlx5_ifc.h
index ca1887dd0423..073b79eacc99 100644
--- a/include/linux/mlx5/mlx5_ifc.h
+++ b/include/linux/mlx5/mlx5_ifc.h
@@ -9960,6 +9960,34 @@ struct mlx5_ifc_pptb_reg_bits {
 	u8         untagged_buff[0x4];
 };
 
+struct mlx5_ifc_sbcam_reg_bits {
+	u8         reserved_at_0[0x8];
+	u8         feature_group[0x8];
+	u8         reserved_at_10[0x8];
+	u8         access_reg_group[0x8];
+
+	u8         reserved_at_20[0x20];
+
+	u8         sb_access_reg_cap_mask[4][0x20];
+
+	u8         reserved_at_c0[0x80];
+
+	u8         sb_feature_cap_mask[4][0x20];
+
+	u8         reserved_at_1c0[0x40];
+
+	u8         cap_total_buffer_size[0x20];
+
+	u8         cap_cell_size[0x10];
+	u8         cap_max_pg_buffers[0x8];
+	u8         cap_num_pool_supported[0x8];
+
+	u8         reserved_at_240[0x8];
+	u8         cap_sbsr_stat_size[0x8];
+	u8         cap_max_tclass_data[0x8];
+	u8         cap_max_cpu_ingress_tclass_sb[0x8];
+};
+
 struct mlx5_ifc_pbmc_reg_bits {
 	u8         reserved_at_0[0x8];
 	u8         local_port[0x8];
