IB/core: Add macros for declaring methods and attributes

This patch adds macros for declaring objects, methods and
attributes. These definitions are later used by downstream patches
to declare some of the default types.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

include/rdma/uverbs_ioctl.h

@@ -34,6 +34,8 @@
 #define _UVERBS_IOCTL_
 
 #include <rdma/uverbs_types.h>
+#include <linux/uaccess.h>
+#include <rdma/rdma_user_ioctl.h>
 
 /*
  * =======================================
@@ -160,10 +162,99 @@ struct uverbs_object_tree_def {
 	const struct uverbs_object_def * const (*objects)[];
 };
 
+#define UA_FLAGS(_flags)  .flags = _flags
+#define __UVERBS_ATTR0(_id, _len, _type, ...)                           \
+	((const struct uverbs_attr_def)				  \
+	 {.id = _id, .attr = {.type = _type, {.len = _len}, .flags = 0, } })
+#define __UVERBS_ATTR1(_id, _len, _type, _flags)                        \
+	((const struct uverbs_attr_def)				  \
+	 {.id = _id, .attr = {.type = _type, {.len = _len}, _flags, } })
+#define __UVERBS_ATTR(_id, _len, _type, _flags, _n, ...)		\
+	__UVERBS_ATTR##_n(_id, _len, _type, _flags)
+/*
+ * In new compiler, UVERBS_ATTR could be simplified by declaring it as
+ * [_id] = {.type = _type, .len = _len, ##__VA_ARGS__}
+ * But since we support older compilers too, we need the more complex code.
+ */
+#define UVERBS_ATTR(_id, _len, _type, ...)				\
+	__UVERBS_ATTR(_id, _len, _type, ##__VA_ARGS__, 1, 0)
+#define UVERBS_ATTR_PTR_IN_SZ(_id, _len, ...)				\
+	UVERBS_ATTR(_id, _len, UVERBS_ATTR_TYPE_PTR_IN, ##__VA_ARGS__)
+/* If sizeof(_type) <= sizeof(u64), this will be inlined rather than a pointer */
+#define UVERBS_ATTR_PTR_IN(_id, _type, ...)				\
+	UVERBS_ATTR_PTR_IN_SZ(_id, sizeof(_type), ##__VA_ARGS__)
+#define UVERBS_ATTR_PTR_OUT_SZ(_id, _len, ...)				\
+	UVERBS_ATTR(_id, _len, UVERBS_ATTR_TYPE_PTR_OUT, ##__VA_ARGS__)
+#define UVERBS_ATTR_PTR_OUT(_id, _type, ...)				\
+	UVERBS_ATTR_PTR_OUT_SZ(_id, sizeof(_type), ##__VA_ARGS__)
+
+/*
+ * In new compiler, UVERBS_ATTR_IDR (and FD) could be simplified by declaring
+ * it as
+ * {.id = _id,								\
+ *  .attr {.type = __obj_class,						\
+ *         .obj = {.obj_type = _idr_type,				\
+ *                       .access = _access                              \
+ *                }, ##__VA_ARGS__ } }
+ * But since we support older compilers too, we need the more complex code.
+ */
+#define ___UVERBS_ATTR_OBJ0(_id, _obj_class, _obj_type, _access, ...)\
+	((const struct uverbs_attr_def)					\
+	{.id = _id,							\
+	 .attr = {.type = _obj_class,					\
+		  {.obj = {.obj_type = _obj_type, .access = _access } },\
+		  .flags = 0} })
+#define ___UVERBS_ATTR_OBJ1(_id, _obj_class, _obj_type, _access, _flags)\
+	((const struct uverbs_attr_def)					\
+	{.id = _id,							\
+	.attr = {.type = _obj_class,					\
+		 {.obj = {.obj_type = _obj_type, .access = _access} },	\
+		  _flags} })
+#define ___UVERBS_ATTR_OBJ(_id, _obj_class, _obj_type, _access, _flags, \
+			   _n, ...)					\
+	___UVERBS_ATTR_OBJ##_n(_id, _obj_class, _obj_type, _access, _flags)
+#define __UVERBS_ATTR_OBJ(_id, _obj_class, _obj_type, _access, ...)	\
+	___UVERBS_ATTR_OBJ(_id, _obj_class, _obj_type, _access,		\
+			   ##__VA_ARGS__, 1, 0)
+#define UVERBS_ATTR_IDR(_id, _idr_type, _access, ...)			 \
+	__UVERBS_ATTR_OBJ(_id, UVERBS_ATTR_TYPE_IDR, _idr_type, _access,\
+			  ##__VA_ARGS__)
+#define UVERBS_ATTR_FD(_id, _fd_type, _access, ...)			\
+	__UVERBS_ATTR_OBJ(_id, UVERBS_ATTR_TYPE_FD, _fd_type,		\
+			  (_access) + BUILD_BUG_ON_ZERO(		\
+				(_access) != UVERBS_ACCESS_NEW &&	\
+				(_access) != UVERBS_ACCESS_READ),	\
+			  ##__VA_ARGS__)
+#define DECLARE_UVERBS_ATTR_SPEC(_name, ...)				\
+	const struct uverbs_attr_def _name = __VA_ARGS__
+
+#define _UVERBS_METHOD_ATTRS_SZ(...)					\
+	(sizeof((const struct uverbs_attr_def * const []){__VA_ARGS__}) /\
+	 sizeof(const struct uverbs_attr_def *))
+#define _UVERBS_METHOD(_id, _handler, _flags, ...)			\
+	((const struct uverbs_method_def) {				\
+	 .id = _id,							\
+	 .flags = _flags,						\
+	 .handler = _handler,						\
+	 .num_attrs = _UVERBS_METHOD_ATTRS_SZ(__VA_ARGS__),		\
+	 .attrs = &(const struct uverbs_attr_def * const []){__VA_ARGS__} })
+#define DECLARE_UVERBS_METHOD(_name, _id, _handler, ...)		\
+	const struct uverbs_method_def _name =				\
+		_UVERBS_METHOD(_id, _handler, 0, ##__VA_ARGS__)
+#define DECLARE_UVERBS_CTX_METHOD(_name, _id, _handler, _flags, ...)	\
+	const struct uverbs_method_def _name =				\
+		_UVERBS_METHOD(_id, _handler,				\
+			       UVERBS_ACTION_FLAG_CREATE_ROOT,		\
+			       ##__VA_ARGS__)
+#define _UVERBS_OBJECT_METHODS_SZ(...)					\
+	(sizeof((const struct uverbs_method_def * const []){__VA_ARGS__}) / \
+	 sizeof(const struct uverbs_method_def *))
 #define _UVERBS_OBJECT(_id, _type_attrs, ...)				\
 	((const struct uverbs_object_def) {				\
 	 .id = _id,							\
-	 .type_attrs = _type_attrs})
+	 .type_attrs = _type_attrs,					\
+	 .num_methods = _UVERBS_OBJECT_METHODS_SZ(__VA_ARGS__),		\
+	 .methods = &(const struct uverbs_method_def * const []){__VA_ARGS__} })
 #define DECLARE_UVERBS_OBJECT(_name, _id, _type_attrs, ...)		\
 	const struct uverbs_object_def _name =				\
 		_UVERBS_OBJECT(_id, _type_attrs, ##__VA_ARGS__)
@@ -235,6 +326,18 @@ static inline bool uverbs_attr_is_valid_in_hash(const struct uverbs_attr_bundle_
 	return test_bit(idx, attrs_hash->valid_bitmap);
 }
 
+static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
+					unsigned int idx)
+{
+	u16 idx_bucket = idx >>	UVERBS_ID_NS_SHIFT;
+
+	if (attrs_bundle->num_buckets <= idx_bucket)
+		return false;
+
+	return uverbs_attr_is_valid_in_hash(&attrs_bundle->hash[idx_bucket],
+					    idx & ~UVERBS_ID_NS_MASK);
+}
+
 /* =================================================
  *	 Definitions -> Specs infrastructure
  * =================================================