/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */

  /*
   * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.

   */
  
  #ifndef _UVERBS_IOCTL_
  #define _UVERBS_IOCTL_
  
  #include <rdma/uverbs_types.h>

  #include <linux/uaccess.h>
  #include <rdma/rdma_user_ioctl.h>

  #include <rdma/ib_user_ioctl_verbs.h>

  #include <rdma/ib_user_ioctl_cmds.h>

  
  /*
   * =======================================
   *	Verbs action specifications
   * =======================================
   */

  enum uverbs_attr_type {
  	UVERBS_ATTR_TYPE_NA,

  	UVERBS_ATTR_TYPE_PTR_IN,
  	UVERBS_ATTR_TYPE_PTR_OUT,

  	UVERBS_ATTR_TYPE_IDR,
  	UVERBS_ATTR_TYPE_FD,

  	UVERBS_ATTR_TYPE_ENUM_IN,

  	UVERBS_ATTR_TYPE_IDRS_ARRAY,

  };

  enum uverbs_obj_access {
  	UVERBS_ACCESS_READ,
  	UVERBS_ACCESS_WRITE,
  	UVERBS_ACCESS_NEW,
  	UVERBS_ACCESS_DESTROY
  };

  /* Specification of a single attribute inside the ioctl message */

  /* good size 16 */

  struct uverbs_attr_spec {

  	u8 type;

  
  	/*

  	 * Support extending attributes by length. Allow the user to provide
  	 * more bytes than ptr.len, but check that everything after is zero'd
  	 * by the user.

  	 */

  	u8 zero_trailing:1;

  	/*
  	 * Valid only for PTR_IN. Allocate and copy the data inside
  	 * the parser
  	 */
  	u8 alloc_and_copy:1;
  	u8 mandatory:1;

  	/* True if this is from UVERBS_ATTR_UHW */
  	u8 is_udata:1;

  	union {

  		struct {

  			/* Current known size to kernel */

  			u16 len;

  			/* User isn't allowed to provide something < min_len */

  			u16 min_len;

  		} ptr;

  		struct {

  			/*
  			 * higher bits mean the namespace and lower bits mean
  			 * the type id within the namespace.
  			 */

  			u16 obj_type;
  			u8 access;

  		} obj;

  
  		struct {
  			u8 num_elems;
  		} enum_def;
  	} u;

  	/* This weird split lets us remove some padding */

  	union {

  		struct {

  			/*
  			 * The enum attribute can select one of the attributes
  			 * contained in the ids array. Currently only PTR_IN
  			 * attributes are supported in the ids array.
  			 */

  			const struct uverbs_attr_spec *ids;

  		} enum_def;

  
  		struct {
  			/*
  			 * higher bits mean the namespace and lower bits mean
  			 * the type id within the namespace.
  			 */
  			u16				obj_type;
  			u16				min_len;
  			u16				max_len;
  			u8				access;
  		} objs_arr;

  	} u2;

  };

  /*

   * Information about the API is loaded into a radix tree. For IOCTL we start
   * with a tuple of:
   *  object_id, attr_id, method_id
   *
   * Which is a 48 bit value, with most of the bits guaranteed to be zero. Based
   * on the current kernel support this is compressed into 16 bit key for the
   * radix tree. Since this compression is entirely internal to the kernel the
   * below limits can be revised if the kernel gains additional data.
   *
   * With 64 leafs per node this is a 3 level radix tree.
   *
   * The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
   * the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.

   *
   * This also encodes the tables for the write() and write() extended commands
   * using the coding
   *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE,command #
   *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE_EX,command_ex #
   * ie the WRITE path is treated as a special method type in the ioctl
   * framework.

   */
  enum uapi_radix_data {
  	UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
  
  	UVERBS_API_ATTR_KEY_BITS = 6,
  	UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
  	UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,

  	UVERBS_API_WRITE_KEY_NUM = 1 << UVERBS_API_ATTR_KEY_BITS,

  
  	UVERBS_API_METHOD_KEY_BITS = 5,
  	UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,

  	UVERBS_API_METHOD_KEY_NUM_CORE = 22,
  	UVERBS_API_METHOD_IS_WRITE = 30 << UVERBS_API_METHOD_KEY_SHIFT,
  	UVERBS_API_METHOD_IS_WRITE_EX = 31 << UVERBS_API_METHOD_KEY_SHIFT,
  	UVERBS_API_METHOD_KEY_NUM_DRIVER =
  		(UVERBS_API_METHOD_IS_WRITE >> UVERBS_API_METHOD_KEY_SHIFT) -
  		UVERBS_API_METHOD_KEY_NUM_CORE,

  	UVERBS_API_METHOD_KEY_MASK = GENMASK(
  		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
  		UVERBS_API_METHOD_KEY_SHIFT),
  
  	UVERBS_API_OBJ_KEY_BITS = 5,
  	UVERBS_API_OBJ_KEY_SHIFT =
  		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT,

  	UVERBS_API_OBJ_KEY_NUM_CORE = 20,

  	UVERBS_API_OBJ_KEY_NUM_DRIVER =
  		(1 << UVERBS_API_OBJ_KEY_BITS) - UVERBS_API_OBJ_KEY_NUM_CORE,
  	UVERBS_API_OBJ_KEY_MASK = GENMASK(31, UVERBS_API_OBJ_KEY_SHIFT),
  
  	/* This id guaranteed to not exist in the radix tree */
  	UVERBS_API_KEY_ERR = 0xFFFFFFFF,
  };
  
  static inline __attribute_const__ u32 uapi_key_obj(u32 id)
  {
  	if (id & UVERBS_API_NS_FLAG) {
  		id &= ~UVERBS_API_NS_FLAG;
  		if (id >= UVERBS_API_OBJ_KEY_NUM_DRIVER)
  			return UVERBS_API_KEY_ERR;
  		id = id + UVERBS_API_OBJ_KEY_NUM_CORE;
  	} else {
  		if (id >= UVERBS_API_OBJ_KEY_NUM_CORE)
  			return UVERBS_API_KEY_ERR;
  	}
  
  	return id << UVERBS_API_OBJ_KEY_SHIFT;
  }
  
  static inline __attribute_const__ bool uapi_key_is_object(u32 key)
  {
  	return (key & ~UVERBS_API_OBJ_KEY_MASK) == 0;
  }
  
  static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
  {
  	if (id & UVERBS_API_NS_FLAG) {
  		id &= ~UVERBS_API_NS_FLAG;
  		if (id >= UVERBS_API_METHOD_KEY_NUM_DRIVER)
  			return UVERBS_API_KEY_ERR;
  		id = id + UVERBS_API_METHOD_KEY_NUM_CORE;
  	} else {
  		id++;
  		if (id >= UVERBS_API_METHOD_KEY_NUM_CORE)
  			return UVERBS_API_KEY_ERR;
  	}
  
  	return id << UVERBS_API_METHOD_KEY_SHIFT;
  }

  static inline __attribute_const__ u32 uapi_key_write_method(u32 id)
  {
  	if (id >= UVERBS_API_WRITE_KEY_NUM)
  		return UVERBS_API_KEY_ERR;
  	return UVERBS_API_METHOD_IS_WRITE | id;
  }
  
  static inline __attribute_const__ u32 uapi_key_write_ex_method(u32 id)
  {
  	if (id >= UVERBS_API_WRITE_KEY_NUM)
  		return UVERBS_API_KEY_ERR;
  	return UVERBS_API_METHOD_IS_WRITE_EX | id;
  }
  
  static inline __attribute_const__ u32
  uapi_key_attr_to_ioctl_method(u32 attr_key)

  {
  	return attr_key &
  	       (UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
  }
  
  static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
  {

  	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
  
  	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&

  	       (key & UVERBS_API_ATTR_KEY_MASK) == 0;
  }

  static inline __attribute_const__ bool uapi_key_is_write_method(u32 key)
  {
  	return (key & UVERBS_API_METHOD_KEY_MASK) == UVERBS_API_METHOD_IS_WRITE;
  }
  
  static inline __attribute_const__ bool uapi_key_is_write_ex_method(u32 key)
  {
  	return (key & UVERBS_API_METHOD_KEY_MASK) ==
  	       UVERBS_API_METHOD_IS_WRITE_EX;
  }

  static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
  {
  	/* 0 is the method slot itself */
  	return ioctl_method_key + 1;
  }
  
  static inline __attribute_const__ u32 uapi_key_attr(u32 id)
  {
  	/*
  	 * The attr is designed to fit in the typical single radix tree node
  	 * of 64 entries. Since allmost all methods have driver attributes we
  	 * organize things so that the driver and core attributes interleave to
  	 * reduce the length of the attributes array in typical cases.
  	 */
  	if (id & UVERBS_API_NS_FLAG) {
  		id &= ~UVERBS_API_NS_FLAG;
  		id++;
  		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
  			return UVERBS_API_KEY_ERR;
  		id = (id << 1) | 0;
  	} else {
  		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
  			return UVERBS_API_KEY_ERR;
  		id = (id << 1) | 1;
  	}
  
  	return id;
  }

  /* Only true for ioctl methods */

  static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
  {

  	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
  
  	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&

  	       (key & UVERBS_API_ATTR_KEY_MASK) != 0;
  }
  
  /*
   * This returns a value in the range [0 to UVERBS_API_ATTR_BKEY_LEN),
   * basically it undoes the reservation of 0 in the ID numbering. attr_key
   * must already be masked with UVERBS_API_ATTR_KEY_MASK, or be the output of
   * uapi_key_attr().
   */
  static inline __attribute_const__ u32 uapi_bkey_attr(u32 attr_key)
  {
  	return attr_key - 1;
  }

  static inline __attribute_const__ u32 uapi_bkey_to_key_attr(u32 attr_bkey)
  {
  	return attr_bkey + 1;
  }

  /*

   * =======================================
   *	Verbs definitions
   * =======================================
   */

  struct uverbs_attr_def {
  	u16                           id;
  	struct uverbs_attr_spec       attr;
  };
  
  struct uverbs_method_def {
  	u16                                  id;
  	/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
  	u32				     flags;
  	size_t				     num_attrs;
  	const struct uverbs_attr_def * const (*attrs)[];

  	int (*handler)(struct uverbs_attr_bundle *attrs);

  };

  struct uverbs_object_def {

  	u16					 id;

  	const struct uverbs_obj_type	        *type_attrs;

  	size_t				         num_methods;
  	const struct uverbs_method_def * const (*methods)[];
  };

  enum uapi_definition_kind {
  	UAPI_DEF_END = 0,

  	UAPI_DEF_OBJECT_START,
  	UAPI_DEF_WRITE,

  	UAPI_DEF_CHAIN_OBJ_TREE,
  	UAPI_DEF_CHAIN,

  	UAPI_DEF_IS_SUPPORTED_FUNC,
  	UAPI_DEF_IS_SUPPORTED_DEV_FN,
  };
  
  enum uapi_definition_scope {
  	UAPI_SCOPE_OBJECT = 1,

  	UAPI_SCOPE_METHOD = 2,

  };

  struct uapi_definition {
  	u8 kind;

  	u8 scope;

  	union {
  		struct {
  			u16 object_id;
  		} object_start;

  		struct {

  			u16 command_num;

  			u8 is_ex:1;
  			u8 has_udata:1;
  			u8 has_resp:1;
  			u8 req_size;
  			u8 resp_size;

  		} write;

  	};
  
  	union {

  		bool (*func_is_supported)(struct ib_device *device);

  		int (*func_write)(struct uverbs_attr_bundle *attrs);

  		const struct uapi_definition *chain;
  		const struct uverbs_object_def *chain_obj_tree;

  		size_t needs_fn_offset;

  	};
  };

  /* Define things connected to object_id */
  #define DECLARE_UVERBS_OBJECT(_object_id, ...)                                 \
  	{                                                                      \
  		.kind = UAPI_DEF_OBJECT_START,                                 \
  		.object_start = { .object_id = _object_id },                   \
  	},                                                                     \
  		##__VA_ARGS__
  
  /* Use in a var_args of DECLARE_UVERBS_OBJECT */

  #define DECLARE_UVERBS_WRITE(_command_num, _func, _cmd_desc, ...)              \

  	{                                                                      \
  		.kind = UAPI_DEF_WRITE,                                        \
  		.scope = UAPI_SCOPE_OBJECT,                                    \
  		.write = { .is_ex = 0, .command_num = _command_num },          \
  		.func_write = _func,                                           \

  		_cmd_desc,                                                     \

  	},                                                                     \
  		##__VA_ARGS__
  
  /* Use in a var_args of DECLARE_UVERBS_OBJECT */

  #define DECLARE_UVERBS_WRITE_EX(_command_num, _func, _cmd_desc, ...)           \

  	{                                                                      \
  		.kind = UAPI_DEF_WRITE,                                        \
  		.scope = UAPI_SCOPE_OBJECT,                                    \
  		.write = { .is_ex = 1, .command_num = _command_num },          \

  		.func_write = _func,                                           \

  		_cmd_desc,                                                     \

  	},                                                                     \
  		##__VA_ARGS__

  /*
   * Object is only supported if the function pointer named ibdev_fn in struct
   * ib_device is not NULL.
   */
  #define UAPI_DEF_OBJ_NEEDS_FN(ibdev_fn)                                        \
  	{                                                                      \
  		.kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
  		.scope = UAPI_SCOPE_OBJECT,                                    \
  		.needs_fn_offset =                                             \

  			offsetof(struct ib_device_ops, ibdev_fn) +             \

  			BUILD_BUG_ON_ZERO(sizeof_field(struct ib_device_ops,   \
  						       ibdev_fn) !=            \
  					  sizeof(void *)),                     \

  	}

  /*
   * Method is only supported if the function pointer named ibdev_fn in struct
   * ib_device is not NULL.
   */
  #define UAPI_DEF_METHOD_NEEDS_FN(ibdev_fn)                                     \
  	{                                                                      \
  		.kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
  		.scope = UAPI_SCOPE_METHOD,                                    \
  		.needs_fn_offset =                                             \

  			offsetof(struct ib_device_ops, ibdev_fn) +             \

  			BUILD_BUG_ON_ZERO(sizeof_field(struct ib_device_ops,   \
  						       ibdev_fn) !=            \
  					  sizeof(void *)),                     \

  	}

  /* Call a function to determine if the entire object is supported or not */
  #define UAPI_DEF_IS_OBJ_SUPPORTED(_func)                                       \
  	{                                                                      \
  		.kind = UAPI_DEF_IS_SUPPORTED_FUNC,                            \
  		.scope = UAPI_SCOPE_OBJECT, .func_is_supported = _func,        \
  	}

  /* Include another struct uapi_definition in this one */
  #define UAPI_DEF_CHAIN(_def_var)                                               \
  	{                                                                      \
  		.kind = UAPI_DEF_CHAIN, .chain = _def_var,                     \
  	}
  
  /* Temporary until the tree base description is replaced */

  #define UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, _object_ptr, ...)                \

  	{                                                                      \
  		.kind = UAPI_DEF_CHAIN_OBJ_TREE,                               \
  		.object_start = { .object_id = _object_enum },                 \
  		.chain_obj_tree = _object_ptr,                                 \

  	},								       \

  		##__VA_ARGS__

  #define UAPI_DEF_CHAIN_OBJ_TREE_NAMED(_object_enum, ...)                       \
  	UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, &UVERBS_OBJECT(_object_enum),    \
  				##__VA_ARGS__)

  /*
   * =======================================
   *	Attribute Specifications
   * =======================================
   */

  #define UVERBS_ATTR_SIZE(_min_len, _len)			\

  	.u.ptr.min_len = _min_len, .u.ptr.len = _len

  #define UVERBS_ATTR_NO_DATA() UVERBS_ATTR_SIZE(0, 0)

  /*
   * Specifies a uapi structure that cannot be extended. The user must always
   * supply the whole structure and nothing more. The structure must be declared
   * in a header under include/uapi/rdma.
   */
  #define UVERBS_ATTR_TYPE(_type)					\
  	.u.ptr.min_len = sizeof(_type), .u.ptr.len = sizeof(_type)
  /*
   * Specifies a uapi structure where the user must provide at least up to
   * member 'last'.  Anything after last and up until the end of the structure
   * can be non-zero, anything longer than the end of the structure must be
   * zero. The structure must be declared in a header under include/uapi/rdma.
   */
  #define UVERBS_ATTR_STRUCT(_type, _last)                                       \
  	.zero_trailing = 1,                                                    \

  	UVERBS_ATTR_SIZE(offsetofend(_type, _last), sizeof(_type))

  /*
   * Specifies at least min_len bytes must be passed in, but the amount can be
   * larger, up to the protocol maximum size. No check for zeroing is done.
   */
  #define UVERBS_ATTR_MIN_SIZE(_min_len) UVERBS_ATTR_SIZE(_min_len, USHRT_MAX)

  /* Must be used in the '...' of any UVERBS_ATTR */

  #define UA_ALLOC_AND_COPY .alloc_and_copy = 1
  #define UA_MANDATORY .mandatory = 1

  #define UA_OPTIONAL .mandatory = 0

  /*
   * min_len must be bigger than 0 and _max_len must be smaller than 4095.  Only
   * READ\WRITE accesses are supported.
   */
  #define UVERBS_ATTR_IDRS_ARR(_attr_id, _idr_type, _access, _min_len, _max_len, \
  			     ...)                                              \
  	(&(const struct uverbs_attr_def){                                      \
  		.id = (_attr_id) +                                             \
  		      BUILD_BUG_ON_ZERO((_min_len) == 0 ||                     \
  					(_max_len) >                           \
  						PAGE_SIZE / sizeof(void *) ||  \
  					(_min_len) > (_max_len) ||             \
  					(_access) == UVERBS_ACCESS_NEW ||      \
  					(_access) == UVERBS_ACCESS_DESTROY),   \
  		.attr = { .type = UVERBS_ATTR_TYPE_IDRS_ARRAY,                 \
  			  .u2.objs_arr.obj_type = _idr_type,                   \
  			  .u2.objs_arr.access = _access,                       \
  			  .u2.objs_arr.min_len = _min_len,                     \
  			  .u2.objs_arr.max_len = _max_len,                     \
  			  __VA_ARGS__ } })

  /*
   * Only for use with UVERBS_ATTR_IDR, allows any uobject type to be accepted,
   * the user must validate the type of the uobject instead.
   */
  #define UVERBS_IDR_ANY_OBJECT 0xFFFF

  #define UVERBS_ATTR_IDR(_attr_id, _idr_type, _access, ...)                     \

  	(&(const struct uverbs_attr_def){                                      \

  		.id = _attr_id,                                                \
  		.attr = { .type = UVERBS_ATTR_TYPE_IDR,                        \
  			  .u.obj.obj_type = _idr_type,                         \
  			  .u.obj.access = _access,                             \
  			  __VA_ARGS__ } })
  
  #define UVERBS_ATTR_FD(_attr_id, _fd_type, _access, ...)                       \

  	(&(const struct uverbs_attr_def){                                      \

  		.id = (_attr_id) +                                             \
  		      BUILD_BUG_ON_ZERO((_access) != UVERBS_ACCESS_NEW &&      \
  					(_access) != UVERBS_ACCESS_READ),      \
  		.attr = { .type = UVERBS_ATTR_TYPE_FD,                         \
  			  .u.obj.obj_type = _fd_type,                          \
  			  .u.obj.access = _access,                             \
  			  __VA_ARGS__ } })
  
  #define UVERBS_ATTR_PTR_IN(_attr_id, _type, ...)                               \

  	(&(const struct uverbs_attr_def){                                      \

  		.id = _attr_id,                                                \
  		.attr = { .type = UVERBS_ATTR_TYPE_PTR_IN,                     \
  			  _type,                                               \
  			  __VA_ARGS__ } })
  
  #define UVERBS_ATTR_PTR_OUT(_attr_id, _type, ...)                              \

  	(&(const struct uverbs_attr_def){                                      \

  		.id = _attr_id,                                                \
  		.attr = { .type = UVERBS_ATTR_TYPE_PTR_OUT,                    \
  			  _type,                                               \
  			  __VA_ARGS__ } })
  
  /* _enum_arry should be a 'static const union uverbs_attr_spec[]' */
  #define UVERBS_ATTR_ENUM_IN(_attr_id, _enum_arr, ...)                          \

  	(&(const struct uverbs_attr_def){                                      \

  		.id = _attr_id,                                                \
  		.attr = { .type = UVERBS_ATTR_TYPE_ENUM_IN,                    \
  			  .u2.enum_def.ids = _enum_arr,                        \
  			  .u.enum_def.num_elems = ARRAY_SIZE(_enum_arr),       \
  			  __VA_ARGS__ },                                       \
  	})

  /* An input value that is a member in the enum _enum_type. */
  #define UVERBS_ATTR_CONST_IN(_attr_id, _enum_type, ...)                        \
  	UVERBS_ATTR_PTR_IN(                                                    \
  		_attr_id,                                                      \
  		UVERBS_ATTR_SIZE(                                              \
  			sizeof(u64) + BUILD_BUG_ON_ZERO(!sizeof(_enum_type)),  \
  			sizeof(u64)),                                          \
  		__VA_ARGS__)

  /*

   * An input value that is a bitwise combination of values of _enum_type.
   * This permits the flag value to be passed as either a u32 or u64, it must
   * be retrieved via uverbs_get_flag().
   */
  #define UVERBS_ATTR_FLAGS_IN(_attr_id, _enum_type, ...)                        \
  	UVERBS_ATTR_PTR_IN(                                                    \
  		_attr_id,                                                      \
  		UVERBS_ATTR_SIZE(sizeof(u32) + BUILD_BUG_ON_ZERO(              \
  						       !sizeof(_enum_type *)), \
  				 sizeof(u64)),                                 \
  		__VA_ARGS__)
  
  /*

   * This spec is used in order to pass information to the hardware driver in a
   * legacy way. Every verb that could get driver specific data should get this
   * spec.
   */
  #define UVERBS_ATTR_UHW()                                                      \

  	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_UHW_IN,                                 \

  			   UVERBS_ATTR_MIN_SIZE(0),			       \

  			   UA_OPTIONAL,                                        \
  			   .is_udata = 1),				       \

  	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_UHW_OUT,                               \

  			    UVERBS_ATTR_MIN_SIZE(0),			       \

  			    UA_OPTIONAL,                                       \
  			    .is_udata = 1)

  /* =================================================
   *              Parsing infrastructure
   * =================================================
   */

  struct uverbs_ptr_attr {

  	/*
  	 * If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
  	 * used.
  	 */
  	union {
  		void *ptr;
  		u64 data;
  	};

  	u16		len;

  	u16		uattr_idx;

  	u8		enum_id;

  };

  struct uverbs_obj_attr {
  	struct ib_uobject		*uobject;

  	const struct uverbs_api_attr	*attr_elm;

  };

  struct uverbs_objs_arr_attr {
  	struct ib_uobject **uobjects;
  	u16 len;
  };

  struct uverbs_attr {

  	union {
  		struct uverbs_ptr_attr	ptr_attr;
  		struct uverbs_obj_attr	obj_attr;

  		struct uverbs_objs_arr_attr objs_arr_attr;

  	};

  };

  struct uverbs_attr_bundle {

  	struct ib_udata driver_udata;

  	struct ib_udata ucore;

  	struct ib_uverbs_file *ufile;

  	struct ib_ucontext *context;

  	struct ib_uobject *uobject;

  	DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
  	struct uverbs_attr attrs[];

  };

  static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
  					unsigned int idx)
  {

  	return test_bit(uapi_bkey_attr(uapi_key_attr(idx)),
  			attrs_bundle->attr_present);

  }

  /**
   * rdma_udata_to_drv_context - Helper macro to get the driver's context out of
   *                             ib_udata which is embedded in uverbs_attr_bundle.
   *
   * If udata is not NULL this cannot fail. Otherwise a NULL udata will result
   * in a NULL ucontext pointer, as a safety precaution. Callers should be using
   * 'udata' to determine if the driver call is in user or kernel mode, not
   * 'ucontext'.
   *
   */
  #define rdma_udata_to_drv_context(udata, drv_dev_struct, member)               \
  	(udata ? container_of(container_of(udata, struct uverbs_attr_bundle,   \
  					   driver_udata)                       \
  				      ->context,                               \
  			      drv_dev_struct, member) :                        \
  		 (drv_dev_struct *)NULL)

  #define IS_UVERBS_COPY_ERR(_ret)		((_ret) && (_ret) != -ENOENT)

  static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
  							u16 idx)
  {

  	if (!uverbs_attr_is_valid(attrs_bundle, idx))
  		return ERR_PTR(-ENOENT);

  	return &attrs_bundle->attrs[uapi_bkey_attr(uapi_key_attr(idx))];

  }

  static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs_bundle,
  					  u16 idx)
  {
  	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
  
  	if (IS_ERR(attr))
  		return PTR_ERR(attr);
  
  	return attr->ptr_attr.enum_id;
  }

  static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
  					u16 idx)
  {

  	const struct uverbs_attr *attr;

  	attr = uverbs_attr_get(attrs_bundle, idx);
  	if (IS_ERR(attr))
  		return ERR_CAST(attr);

  	return attr->obj_attr.uobject->object;

  }

  static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_attr_bundle *attrs_bundle,
  							 u16 idx)
  {
  	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
  
  	if (IS_ERR(attr))
  		return ERR_CAST(attr);
  
  	return attr->obj_attr.uobject;
  }

  static inline int
  uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
  {
  	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
  
  	if (IS_ERR(attr))
  		return PTR_ERR(attr);
  
  	return attr->ptr_attr.len;
  }

  void uverbs_finalize_uobj_create(const struct uverbs_attr_bundle *attrs_bundle,
  				 u16 idx);

  /*
   * uverbs_attr_ptr_get_array_size() - Get array size pointer by a ptr
   * attribute.
   * @attrs: The attribute bundle
   * @idx: The ID of the attribute
   * @elem_size: The size of the element in the array
   */
  static inline int
  uverbs_attr_ptr_get_array_size(struct uverbs_attr_bundle *attrs, u16 idx,
  			       size_t elem_size)
  {
  	int size = uverbs_attr_get_len(attrs, idx);
  
  	if (size < 0)
  		return size;
  
  	if (size % elem_size)
  		return -EINVAL;
  
  	return size / elem_size;
  }

  /**
   * uverbs_attr_get_uobjs_arr() - Provides array's properties for attribute for
   * UVERBS_ATTR_TYPE_IDRS_ARRAY.
   * @arr: Returned pointer to array of pointers for uobjects or NULL if
   *       the attribute isn't provided.
   *
   * Return: The array length or 0 if no attribute was provided.
   */
  static inline int uverbs_attr_get_uobjs_arr(
  	const struct uverbs_attr_bundle *attrs_bundle, u16 attr_idx,
  	struct ib_uobject ***arr)
  {
  	const struct uverbs_attr *attr =
  			uverbs_attr_get(attrs_bundle, attr_idx);
  
  	if (IS_ERR(attr)) {
  		*arr = NULL;
  		return 0;
  	}
  
  	*arr = attr->objs_arr_attr.uobjects;
  
  	return attr->objs_arr_attr.len;
  }

  static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
  {
  	return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
  }

  static inline void *uverbs_attr_get_alloced_ptr(
  	const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
  {
  	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
  
  	if (IS_ERR(attr))
  		return (void *)attr;
  
  	return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
  						 attr->ptr_attr.ptr;
  }

  static inline int _uverbs_copy_from(void *to,

  				    const struct uverbs_attr_bundle *attrs_bundle,

  				    size_t idx,
  				    size_t size)

  {
  	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
  
  	if (IS_ERR(attr))
  		return PTR_ERR(attr);

  	/*
  	 * Validation ensures attr->ptr_attr.len >= size. If the caller is

  	 * using UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO then it must call
  	 * uverbs_copy_from_or_zero.

  	 */
  	if (unlikely(size < attr->ptr_attr.len))
  		return -EINVAL;
  
  	if (uverbs_attr_ptr_is_inline(attr))

  		memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);

  	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
  				attr->ptr_attr.len))

  		return -EFAULT;
  
  	return 0;
  }

  static inline int _uverbs_copy_from_or_zero(void *to,
  					    const struct uverbs_attr_bundle *attrs_bundle,
  					    size_t idx,
  					    size_t size)
  {
  	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
  	size_t min_size;
  
  	if (IS_ERR(attr))
  		return PTR_ERR(attr);
  
  	min_size = min_t(size_t, size, attr->ptr_attr.len);
  
  	if (uverbs_attr_ptr_is_inline(attr))
  		memcpy(to, &attr->ptr_attr.data, min_size);
  	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
  				min_size))
  		return -EFAULT;
  
  	if (size > min_size)
  		memset(to + min_size, 0, size - min_size);
  
  	return 0;
  }

  #define uverbs_copy_from(to, attrs_bundle, idx)				      \

  	_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))

  #define uverbs_copy_from_or_zero(to, attrs_bundle, idx)			      \
  	_uverbs_copy_from_or_zero(to, attrs_bundle, idx, sizeof(*to))

  static inline struct ib_ucontext *
  ib_uverbs_get_ucontext(const struct uverbs_attr_bundle *attrs)
  {
  	return ib_uverbs_get_ucontext_file(attrs->ufile);
  }

  #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
  int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
  		       size_t idx, u64 allowed_bits);
  int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
  		       size_t idx, u64 allowed_bits);

  int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
  		   const void *from, size_t size);

  __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
  			     gfp_t flags);
  
  static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
  					  size_t size)
  {
  	return _uverbs_alloc(bundle, size, GFP_KERNEL);
  }
  
  static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
  					   size_t size)
  {
  	return _uverbs_alloc(bundle, size, GFP_KERNEL | __GFP_ZERO);
  }

  
  static inline __malloc void *uverbs_kcalloc(struct uverbs_attr_bundle *bundle,
  					    size_t n, size_t size)
  {
  	size_t bytes;
  
  	if (unlikely(check_mul_overflow(n, size, &bytes)))
  		return ERR_PTR(-EOVERFLOW);
  	return uverbs_zalloc(bundle, bytes);
  }

  int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
  		      size_t idx, s64 lower_bound, u64 upper_bound,
  		      s64 *def_val);

  int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
  				  size_t idx, const void *from, size_t size);

  #else
  static inline int
  uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
  		   size_t idx, u64 allowed_bits)
  {
  	return -EINVAL;
  }
  static inline int
  uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
  		   size_t idx, u64 allowed_bits)
  {
  	return -EINVAL;
  }

  static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
  				 size_t idx, const void *from, size_t size)
  {
  	return -EINVAL;
  }

  static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
  					  size_t size)
  {
  	return ERR_PTR(-EINVAL);
  }
  static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
  					   size_t size)
  {
  	return ERR_PTR(-EINVAL);
  }

  static inline int
  _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
  		  size_t idx, s64 lower_bound, u64 upper_bound,
  		  s64 *def_val)
  {
  	return -EINVAL;
  }

  static inline int
  uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
  			      size_t idx, const void *from, size_t size)
  {
  	return -EINVAL;
  }

  #endif

  #define uverbs_get_const(_to, _attrs_bundle, _idx)                             \
  	({                                                                     \
  		s64 _val;                                                      \
  		int _ret = _uverbs_get_const(&_val, _attrs_bundle, _idx,       \
  					     type_min(typeof(*_to)),           \
  					     type_max(typeof(*_to)), NULL);    \
  		(*_to) = _val;                                                 \
  		_ret;                                                          \
  	})
  
  #define uverbs_get_const_default(_to, _attrs_bundle, _idx, _default)           \
  	({                                                                     \
  		s64 _val;                                                      \
  		s64 _def_val = _default;                                       \
  		int _ret =                                                     \
  			_uverbs_get_const(&_val, _attrs_bundle, _idx,          \
  					  type_min(typeof(*_to)),              \
  					  type_max(typeof(*_to)), &_def_val);  \
  		(*_to) = _val;                                                 \
  		_ret;                                                          \
  	})

  #endif