mlx5: Clear reserved area in set_hca_cap()

Firmware spec requires reserved fields to be cleared when calling
set_hca_cap.  Current code queries and copy to the set area, possibly
resulting in reserved bits not cleared. This patch copies only
writable fields to the set area.

Fix also typo - msx => max
Signed-off-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

drivers/net/ethernet/mellanox/mlx5/core/main.c

@@ -159,6 +159,36 @@ struct mlx5_reg_host_endianess {
 	u8      rsvd[15];
 };
 
+
+#define CAP_MASK(pos, size) ((u64)((1 << (size)) - 1) << (pos))
+
+enum {
+	MLX5_CAP_BITS_RW_MASK	= CAP_MASK(MLX5_CAP_OFF_CMDIF_CSUM, 2) |
+				  CAP_MASK(MLX5_CAP_OFF_DCT, 1),
+};
+
+/* selectively copy writable fields clearing any reserved area
+ */
+static void copy_rw_fields(struct mlx5_hca_cap *to, struct mlx5_hca_cap *from)
+{
+	u64 v64;
+
+	to->log_max_qp = from->log_max_qp & 0x1f;
+	to->log_max_ra_req_dc = from->log_max_ra_req_dc & 0x3f;
+	to->log_max_ra_res_dc = from->log_max_ra_res_dc & 0x3f;
+	to->log_max_ra_req_qp = from->log_max_ra_req_qp & 0x3f;
+	to->log_max_ra_res_qp = from->log_max_ra_res_qp & 0x3f;
+	to->log_max_atomic_size_qp = from->log_max_atomic_size_qp;
+	to->log_max_atomic_size_dc = from->log_max_atomic_size_dc;
+	v64 = be64_to_cpu(from->flags) & MLX5_CAP_BITS_RW_MASK;
+	to->flags = cpu_to_be64(v64);
+}
+
+enum {
+	HCA_CAP_OPMOD_GET_MAX	= 0,
+	HCA_CAP_OPMOD_GET_CUR	= 1,
+};
+
 static int handle_hca_cap(struct mlx5_core_dev *dev)
 {
 	struct mlx5_cmd_query_hca_cap_mbox_out *query_out = NULL;
@@ -180,7 +210,7 @@ static int handle_hca_cap(struct mlx5_core_dev *dev)
 	}
 
 	query_ctx.hdr.opcode = cpu_to_be16(MLX5_CMD_OP_QUERY_HCA_CAP);
-	query_ctx.hdr.opmod  = cpu_to_be16(0x1);
+	query_ctx.hdr.opmod  = cpu_to_be16(HCA_CAP_OPMOD_GET_CUR);
 	err = mlx5_cmd_exec(dev, &query_ctx, sizeof(query_ctx),
 				 query_out, sizeof(*query_out));
 	if (err)
@@ -192,8 +222,7 @@ static int handle_hca_cap(struct mlx5_core_dev *dev)
 		goto query_ex;
 	}
 
-	memcpy(&set_ctx->hca_cap, &query_out->hca_cap,
-	       sizeof(set_ctx->hca_cap));
+	copy_rw_fields(&set_ctx->hca_cap, &query_out->hca_cap);
 
 	if (dev->profile->mask & MLX5_PROF_MASK_QP_SIZE)
 		set_ctx->hca_cap.log_max_qp = dev->profile->log_max_qp;

include/linux/mlx5/device.h

@@ -230,6 +230,11 @@ enum {
 	MLX5_MAX_PAGE_SHIFT		= 31
 };
 
+enum {
+	MLX5_CAP_OFF_DCT		= 41,
+	MLX5_CAP_OFF_CMDIF_CSUM		= 46,
+};
+
 struct mlx5_inbox_hdr {
 	__be16		opcode;
 	u8		rsvd[4];
@@ -319,9 +324,9 @@ struct mlx5_hca_cap {
 	u8	rsvd25[42];
 	__be16  log_uar_page_sz;
 	u8	rsvd26[28];
-	u8	log_msx_atomic_size_qp;
+	u8	log_max_atomic_size_qp;
 	u8	rsvd27[2];
-	u8	log_msx_atomic_size_dc;
+	u8	log_max_atomic_size_dc;
 	u8	rsvd28[76];
 };