When creating a new user context, query device for
    
various limits, for use in sanity checks and
other resource limitation needs.
    
Passing needed info back to userspace in this manner is
preferable to breaking the ABI.
(OFED 1.3 commit 43ca5e9225658b22ef8180bf0eff4faa7f5940cf)
    
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>

Index: libmlx4/src/mlx4.c
===================================================================
--- libmlx4.orig/src/mlx4.c	2008-06-03 15:45:18.000000000 +0300
+++ libmlx4/src/mlx4.c	2008-06-04 08:24:10.000000000 +0300
@@ -104,6 +104,7 @@ static struct ibv_context *mlx4_alloc_co
 	struct ibv_get_context		cmd;
 	struct mlx4_alloc_ucontext_resp resp;
 	int				i;
+	struct ibv_device_attr		dev_attrs;
 
 	context = calloc(1, sizeof *context);
 	if (!context)
@@ -156,8 +157,20 @@ static struct ibv_context *mlx4_alloc_co
 
 	context->ibv_ctx.ops = mlx4_ctx_ops;
 
+	if (mlx4_query_device(&context->ibv_ctx, &dev_attrs))
+		goto query_free;
+
+	context->max_qp_wr = dev_attrs.max_qp_wr;
+	context->max_sge = dev_attrs.max_sge;
+	context->max_cqe = dev_attrs.max_cqe;
+
 	return &context->ibv_ctx;
 
+query_free:
+	munmap(context->uar, to_mdev(ibdev)->page_size);
+	if (context->bf_page)
+		munmap(context->bf_page, to_mdev(ibdev)->page_size);
+
 err_free:
 	free(context);
 	return NULL;
Index: libmlx4/src/mlx4.h
===================================================================
--- libmlx4.orig/src/mlx4.h	2008-06-03 15:45:18.000000000 +0300
+++ libmlx4/src/mlx4.h	2008-06-04 08:24:10.000000000 +0300
@@ -83,6 +83,20 @@
 
 #define PFX		"mlx4: "
 
+#ifndef max
+#define max(a,b) \
+	({ typeof (a) _a = (a); \
+	   typeof (b) _b = (b); \
+	   _a > _b ? _a : _b; })
+#endif
+
+#ifndef min
+#define min(a,b) \
+	({ typeof (a) _a = (a); \
+	   typeof (b) _b = (b); \
+	   _a < _b ? _a : _b; })
+#endif
+
 enum {
 	MLX4_CQ_ENTRY_SIZE		= 0x20
 };
@@ -156,6 +170,9 @@ struct mlx4_context {
 	int				num_qps;
 	int				qp_table_shift;
 	int				qp_table_mask;
+	int				max_qp_wr;
+	int				max_sge;
+	int				max_cqe;
 
 	struct mlx4_db_page	       *db_list[MLX4_NUM_DB_TYPE];
 	pthread_mutex_t			db_list_mutex;