xref: /openbmc/linux/include/rdma/uverbs_ioctl.h (revision 9b93eb47)
1 /*
2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #ifndef _UVERBS_IOCTL_
34 #define _UVERBS_IOCTL_
35 
36 #include <rdma/uverbs_types.h>
37 #include <linux/uaccess.h>
38 #include <rdma/rdma_user_ioctl.h>
39 #include <rdma/ib_user_ioctl_verbs.h>
40 #include <rdma/ib_user_ioctl_cmds.h>
41 
42 /*
43  * =======================================
44  *	Verbs action specifications
45  * =======================================
46  */
47 
48 enum uverbs_attr_type {
49 	UVERBS_ATTR_TYPE_NA,
50 	UVERBS_ATTR_TYPE_PTR_IN,
51 	UVERBS_ATTR_TYPE_PTR_OUT,
52 	UVERBS_ATTR_TYPE_IDR,
53 	UVERBS_ATTR_TYPE_FD,
54 	UVERBS_ATTR_TYPE_ENUM_IN,
55 	UVERBS_ATTR_TYPE_IDRS_ARRAY,
56 };
57 
58 enum uverbs_obj_access {
59 	UVERBS_ACCESS_READ,
60 	UVERBS_ACCESS_WRITE,
61 	UVERBS_ACCESS_NEW,
62 	UVERBS_ACCESS_DESTROY
63 };
64 
65 /* Specification of a single attribute inside the ioctl message */
66 /* good size 16 */
67 struct uverbs_attr_spec {
68 	u8 type;
69 
70 	/*
71 	 * Support extending attributes by length. Allow the user to provide
72 	 * more bytes than ptr.len, but check that everything after is zero'd
73 	 * by the user.
74 	 */
75 	u8 zero_trailing:1;
76 	/*
77 	 * Valid only for PTR_IN. Allocate and copy the data inside
78 	 * the parser
79 	 */
80 	u8 alloc_and_copy:1;
81 	u8 mandatory:1;
82 	/* True if this is from UVERBS_ATTR_UHW */
83 	u8 is_udata:1;
84 
85 	union {
86 		struct {
87 			/* Current known size to kernel */
88 			u16 len;
89 			/* User isn't allowed to provide something < min_len */
90 			u16 min_len;
91 		} ptr;
92 
93 		struct {
94 			/*
95 			 * higher bits mean the namespace and lower bits mean
96 			 * the type id within the namespace.
97 			 */
98 			u16 obj_type;
99 			u8 access;
100 		} obj;
101 
102 		struct {
103 			u8 num_elems;
104 		} enum_def;
105 	} u;
106 
107 	/* This weird split lets us remove some padding */
108 	union {
109 		struct {
110 			/*
111 			 * The enum attribute can select one of the attributes
112 			 * contained in the ids array. Currently only PTR_IN
113 			 * attributes are supported in the ids array.
114 			 */
115 			const struct uverbs_attr_spec *ids;
116 		} enum_def;
117 
118 		struct {
119 			/*
120 			 * higher bits mean the namespace and lower bits mean
121 			 * the type id within the namespace.
122 			 */
123 			u16				obj_type;
124 			u16				min_len;
125 			u16				max_len;
126 			u8				access;
127 		} objs_arr;
128 	} u2;
129 };
130 
131 /*
132  * Information about the API is loaded into a radix tree. For IOCTL we start
133  * with a tuple of:
134  *  object_id, attr_id, method_id
135  *
136  * Which is a 48 bit value, with most of the bits guaranteed to be zero. Based
137  * on the current kernel support this is compressed into 16 bit key for the
138  * radix tree. Since this compression is entirely internal to the kernel the
139  * below limits can be revised if the kernel gains additional data.
140  *
141  * With 64 leafs per node this is a 3 level radix tree.
142  *
143  * The tree encodes multiple types, and uses a scheme where OBJ_ID,0,0 returns
144  * the object slot, and OBJ_ID,METH_ID,0 and returns the method slot.
145  *
146  * This also encodes the tables for the write() and write() extended commands
147  * using the coding
148  *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE,command #
149  *   OBJ_ID,UVERBS_API_METHOD_IS_WRITE_EX,command_ex #
150  * ie the WRITE path is treated as a special method type in the ioctl
151  * framework.
152  */
153 enum uapi_radix_data {
154 	UVERBS_API_NS_FLAG = 1U << UVERBS_ID_NS_SHIFT,
155 
156 	UVERBS_API_ATTR_KEY_BITS = 6,
157 	UVERBS_API_ATTR_KEY_MASK = GENMASK(UVERBS_API_ATTR_KEY_BITS - 1, 0),
158 	UVERBS_API_ATTR_BKEY_LEN = (1 << UVERBS_API_ATTR_KEY_BITS) - 1,
159 	UVERBS_API_WRITE_KEY_NUM = 1 << UVERBS_API_ATTR_KEY_BITS,
160 
161 	UVERBS_API_METHOD_KEY_BITS = 5,
162 	UVERBS_API_METHOD_KEY_SHIFT = UVERBS_API_ATTR_KEY_BITS,
163 	UVERBS_API_METHOD_KEY_NUM_CORE = 22,
164 	UVERBS_API_METHOD_IS_WRITE = 30 << UVERBS_API_METHOD_KEY_SHIFT,
165 	UVERBS_API_METHOD_IS_WRITE_EX = 31 << UVERBS_API_METHOD_KEY_SHIFT,
166 	UVERBS_API_METHOD_KEY_NUM_DRIVER =
167 		(UVERBS_API_METHOD_IS_WRITE >> UVERBS_API_METHOD_KEY_SHIFT) -
168 		UVERBS_API_METHOD_KEY_NUM_CORE,
169 	UVERBS_API_METHOD_KEY_MASK = GENMASK(
170 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT - 1,
171 		UVERBS_API_METHOD_KEY_SHIFT),
172 
173 	UVERBS_API_OBJ_KEY_BITS = 5,
174 	UVERBS_API_OBJ_KEY_SHIFT =
175 		UVERBS_API_METHOD_KEY_BITS + UVERBS_API_METHOD_KEY_SHIFT,
176 	UVERBS_API_OBJ_KEY_NUM_CORE = 24,
177 	UVERBS_API_OBJ_KEY_NUM_DRIVER =
178 		(1 << UVERBS_API_OBJ_KEY_BITS) - UVERBS_API_OBJ_KEY_NUM_CORE,
179 	UVERBS_API_OBJ_KEY_MASK = GENMASK(31, UVERBS_API_OBJ_KEY_SHIFT),
180 
181 	/* This id guaranteed to not exist in the radix tree */
182 	UVERBS_API_KEY_ERR = 0xFFFFFFFF,
183 };
184 
185 static inline __attribute_const__ u32 uapi_key_obj(u32 id)
186 {
187 	if (id & UVERBS_API_NS_FLAG) {
188 		id &= ~UVERBS_API_NS_FLAG;
189 		if (id >= UVERBS_API_OBJ_KEY_NUM_DRIVER)
190 			return UVERBS_API_KEY_ERR;
191 		id = id + UVERBS_API_OBJ_KEY_NUM_CORE;
192 	} else {
193 		if (id >= UVERBS_API_OBJ_KEY_NUM_CORE)
194 			return UVERBS_API_KEY_ERR;
195 	}
196 
197 	return id << UVERBS_API_OBJ_KEY_SHIFT;
198 }
199 
200 static inline __attribute_const__ bool uapi_key_is_object(u32 key)
201 {
202 	return (key & ~UVERBS_API_OBJ_KEY_MASK) == 0;
203 }
204 
205 static inline __attribute_const__ u32 uapi_key_ioctl_method(u32 id)
206 {
207 	if (id & UVERBS_API_NS_FLAG) {
208 		id &= ~UVERBS_API_NS_FLAG;
209 		if (id >= UVERBS_API_METHOD_KEY_NUM_DRIVER)
210 			return UVERBS_API_KEY_ERR;
211 		id = id + UVERBS_API_METHOD_KEY_NUM_CORE;
212 	} else {
213 		id++;
214 		if (id >= UVERBS_API_METHOD_KEY_NUM_CORE)
215 			return UVERBS_API_KEY_ERR;
216 	}
217 
218 	return id << UVERBS_API_METHOD_KEY_SHIFT;
219 }
220 
221 static inline __attribute_const__ u32 uapi_key_write_method(u32 id)
222 {
223 	if (id >= UVERBS_API_WRITE_KEY_NUM)
224 		return UVERBS_API_KEY_ERR;
225 	return UVERBS_API_METHOD_IS_WRITE | id;
226 }
227 
228 static inline __attribute_const__ u32 uapi_key_write_ex_method(u32 id)
229 {
230 	if (id >= UVERBS_API_WRITE_KEY_NUM)
231 		return UVERBS_API_KEY_ERR;
232 	return UVERBS_API_METHOD_IS_WRITE_EX | id;
233 }
234 
235 static inline __attribute_const__ u32
236 uapi_key_attr_to_ioctl_method(u32 attr_key)
237 {
238 	return attr_key &
239 	       (UVERBS_API_OBJ_KEY_MASK | UVERBS_API_METHOD_KEY_MASK);
240 }
241 
242 static inline __attribute_const__ bool uapi_key_is_ioctl_method(u32 key)
243 {
244 	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
245 
246 	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
247 	       (key & UVERBS_API_ATTR_KEY_MASK) == 0;
248 }
249 
250 static inline __attribute_const__ bool uapi_key_is_write_method(u32 key)
251 {
252 	return (key & UVERBS_API_METHOD_KEY_MASK) == UVERBS_API_METHOD_IS_WRITE;
253 }
254 
255 static inline __attribute_const__ bool uapi_key_is_write_ex_method(u32 key)
256 {
257 	return (key & UVERBS_API_METHOD_KEY_MASK) ==
258 	       UVERBS_API_METHOD_IS_WRITE_EX;
259 }
260 
261 static inline __attribute_const__ u32 uapi_key_attrs_start(u32 ioctl_method_key)
262 {
263 	/* 0 is the method slot itself */
264 	return ioctl_method_key + 1;
265 }
266 
267 static inline __attribute_const__ u32 uapi_key_attr(u32 id)
268 {
269 	/*
270 	 * The attr is designed to fit in the typical single radix tree node
271 	 * of 64 entries. Since allmost all methods have driver attributes we
272 	 * organize things so that the driver and core attributes interleave to
273 	 * reduce the length of the attributes array in typical cases.
274 	 */
275 	if (id & UVERBS_API_NS_FLAG) {
276 		id &= ~UVERBS_API_NS_FLAG;
277 		id++;
278 		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
279 			return UVERBS_API_KEY_ERR;
280 		id = (id << 1) | 0;
281 	} else {
282 		if (id >= 1 << (UVERBS_API_ATTR_KEY_BITS - 1))
283 			return UVERBS_API_KEY_ERR;
284 		id = (id << 1) | 1;
285 	}
286 
287 	return id;
288 }
289 
290 /* Only true for ioctl methods */
291 static inline __attribute_const__ bool uapi_key_is_attr(u32 key)
292 {
293 	unsigned int method = key & UVERBS_API_METHOD_KEY_MASK;
294 
295 	return method != 0 && method < UVERBS_API_METHOD_IS_WRITE &&
296 	       (key & UVERBS_API_ATTR_KEY_MASK) != 0;
297 }
298 
299 /*
300  * This returns a value in the range [0 to UVERBS_API_ATTR_BKEY_LEN),
301  * basically it undoes the reservation of 0 in the ID numbering. attr_key
302  * must already be masked with UVERBS_API_ATTR_KEY_MASK, or be the output of
303  * uapi_key_attr().
304  */
305 static inline __attribute_const__ u32 uapi_bkey_attr(u32 attr_key)
306 {
307 	return attr_key - 1;
308 }
309 
310 static inline __attribute_const__ u32 uapi_bkey_to_key_attr(u32 attr_bkey)
311 {
312 	return attr_bkey + 1;
313 }
314 
315 /*
316  * =======================================
317  *	Verbs definitions
318  * =======================================
319  */
320 
321 struct uverbs_attr_def {
322 	u16                           id;
323 	struct uverbs_attr_spec       attr;
324 };
325 
326 struct uverbs_method_def {
327 	u16                                  id;
328 	/* Combination of bits from enum UVERBS_ACTION_FLAG_XXXX */
329 	u32				     flags;
330 	size_t				     num_attrs;
331 	const struct uverbs_attr_def * const (*attrs)[];
332 	int (*handler)(struct uverbs_attr_bundle *attrs);
333 };
334 
335 struct uverbs_object_def {
336 	u16					 id;
337 	const struct uverbs_obj_type	        *type_attrs;
338 	size_t				         num_methods;
339 	const struct uverbs_method_def * const (*methods)[];
340 };
341 
342 enum uapi_definition_kind {
343 	UAPI_DEF_END = 0,
344 	UAPI_DEF_OBJECT_START,
345 	UAPI_DEF_WRITE,
346 	UAPI_DEF_CHAIN_OBJ_TREE,
347 	UAPI_DEF_CHAIN,
348 	UAPI_DEF_IS_SUPPORTED_FUNC,
349 	UAPI_DEF_IS_SUPPORTED_DEV_FN,
350 };
351 
352 enum uapi_definition_scope {
353 	UAPI_SCOPE_OBJECT = 1,
354 	UAPI_SCOPE_METHOD = 2,
355 };
356 
357 struct uapi_definition {
358 	u8 kind;
359 	u8 scope;
360 	union {
361 		struct {
362 			u16 object_id;
363 		} object_start;
364 		struct {
365 			u16 command_num;
366 			u8 is_ex:1;
367 			u8 has_udata:1;
368 			u8 has_resp:1;
369 			u8 req_size;
370 			u8 resp_size;
371 		} write;
372 	};
373 
374 	union {
375 		bool (*func_is_supported)(struct ib_device *device);
376 		int (*func_write)(struct uverbs_attr_bundle *attrs);
377 		const struct uapi_definition *chain;
378 		const struct uverbs_object_def *chain_obj_tree;
379 		size_t needs_fn_offset;
380 	};
381 };
382 
383 /* Define things connected to object_id */
384 #define DECLARE_UVERBS_OBJECT(_object_id, ...)                                 \
385 	{                                                                      \
386 		.kind = UAPI_DEF_OBJECT_START,                                 \
387 		.object_start = { .object_id = _object_id },                   \
388 	},                                                                     \
389 		##__VA_ARGS__
390 
391 /* Use in a var_args of DECLARE_UVERBS_OBJECT */
392 #define DECLARE_UVERBS_WRITE(_command_num, _func, _cmd_desc, ...)              \
393 	{                                                                      \
394 		.kind = UAPI_DEF_WRITE,                                        \
395 		.scope = UAPI_SCOPE_OBJECT,                                    \
396 		.write = { .is_ex = 0, .command_num = _command_num },          \
397 		.func_write = _func,                                           \
398 		_cmd_desc,                                                     \
399 	},                                                                     \
400 		##__VA_ARGS__
401 
402 /* Use in a var_args of DECLARE_UVERBS_OBJECT */
403 #define DECLARE_UVERBS_WRITE_EX(_command_num, _func, _cmd_desc, ...)           \
404 	{                                                                      \
405 		.kind = UAPI_DEF_WRITE,                                        \
406 		.scope = UAPI_SCOPE_OBJECT,                                    \
407 		.write = { .is_ex = 1, .command_num = _command_num },          \
408 		.func_write = _func,                                           \
409 		_cmd_desc,                                                     \
410 	},                                                                     \
411 		##__VA_ARGS__
412 
413 /*
414  * Object is only supported if the function pointer named ibdev_fn in struct
415  * ib_device is not NULL.
416  */
417 #define UAPI_DEF_OBJ_NEEDS_FN(ibdev_fn)                                        \
418 	{                                                                      \
419 		.kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
420 		.scope = UAPI_SCOPE_OBJECT,                                    \
421 		.needs_fn_offset =                                             \
422 			offsetof(struct ib_device_ops, ibdev_fn) +             \
423 			BUILD_BUG_ON_ZERO(                                     \
424 			    sizeof(((struct ib_device_ops *)0)->ibdev_fn) !=   \
425 			    sizeof(void *)),				       \
426 	}
427 
428 /*
429  * Method is only supported if the function pointer named ibdev_fn in struct
430  * ib_device is not NULL.
431  */
432 #define UAPI_DEF_METHOD_NEEDS_FN(ibdev_fn)                                     \
433 	{                                                                      \
434 		.kind = UAPI_DEF_IS_SUPPORTED_DEV_FN,                          \
435 		.scope = UAPI_SCOPE_METHOD,                                    \
436 		.needs_fn_offset =                                             \
437 			offsetof(struct ib_device_ops, ibdev_fn) +             \
438 			BUILD_BUG_ON_ZERO(                                     \
439 			    sizeof(((struct ib_device_ops *)0)->ibdev_fn) !=   \
440 			    sizeof(void *)),                                   \
441 	}
442 
443 /* Call a function to determine if the entire object is supported or not */
444 #define UAPI_DEF_IS_OBJ_SUPPORTED(_func)                                       \
445 	{                                                                      \
446 		.kind = UAPI_DEF_IS_SUPPORTED_FUNC,                            \
447 		.scope = UAPI_SCOPE_OBJECT, .func_is_supported = _func,        \
448 	}
449 
450 /* Include another struct uapi_definition in this one */
451 #define UAPI_DEF_CHAIN(_def_var)                                               \
452 	{                                                                      \
453 		.kind = UAPI_DEF_CHAIN, .chain = _def_var,                     \
454 	}
455 
456 /* Temporary until the tree base description is replaced */
457 #define UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, _object_ptr, ...)                \
458 	{                                                                      \
459 		.kind = UAPI_DEF_CHAIN_OBJ_TREE,                               \
460 		.object_start = { .object_id = _object_enum },                 \
461 		.chain_obj_tree = _object_ptr,                                 \
462 	},								       \
463 		##__VA_ARGS__
464 #define UAPI_DEF_CHAIN_OBJ_TREE_NAMED(_object_enum, ...)                       \
465 	UAPI_DEF_CHAIN_OBJ_TREE(_object_enum, &UVERBS_OBJECT(_object_enum),    \
466 				##__VA_ARGS__)
467 
468 /*
469  * =======================================
470  *	Attribute Specifications
471  * =======================================
472  */
473 
474 #define UVERBS_ATTR_SIZE(_min_len, _len)			\
475 	.u.ptr.min_len = _min_len, .u.ptr.len = _len
476 
477 #define UVERBS_ATTR_NO_DATA() UVERBS_ATTR_SIZE(0, 0)
478 
479 /*
480  * Specifies a uapi structure that cannot be extended. The user must always
481  * supply the whole structure and nothing more. The structure must be declared
482  * in a header under include/uapi/rdma.
483  */
484 #define UVERBS_ATTR_TYPE(_type)					\
485 	.u.ptr.min_len = sizeof(_type), .u.ptr.len = sizeof(_type)
486 /*
487  * Specifies a uapi structure where the user must provide at least up to
488  * member 'last'.  Anything after last and up until the end of the structure
489  * can be non-zero, anything longer than the end of the structure must be
490  * zero. The structure must be declared in a header under include/uapi/rdma.
491  */
492 #define UVERBS_ATTR_STRUCT(_type, _last)                                       \
493 	.zero_trailing = 1,                                                    \
494 	UVERBS_ATTR_SIZE(((uintptr_t)(&((_type *)0)->_last + 1)),              \
495 			 sizeof(_type))
496 /*
497  * Specifies at least min_len bytes must be passed in, but the amount can be
498  * larger, up to the protocol maximum size. No check for zeroing is done.
499  */
500 #define UVERBS_ATTR_MIN_SIZE(_min_len) UVERBS_ATTR_SIZE(_min_len, USHRT_MAX)
501 
502 /* Must be used in the '...' of any UVERBS_ATTR */
503 #define UA_ALLOC_AND_COPY .alloc_and_copy = 1
504 #define UA_MANDATORY .mandatory = 1
505 #define UA_OPTIONAL .mandatory = 0
506 
507 /*
508  * min_len must be bigger than 0 and _max_len must be smaller than 4095.  Only
509  * READ\WRITE accesses are supported.
510  */
511 #define UVERBS_ATTR_IDRS_ARR(_attr_id, _idr_type, _access, _min_len, _max_len, \
512 			     ...)                                              \
513 	(&(const struct uverbs_attr_def){                                      \
514 		.id = (_attr_id) +                                             \
515 		      BUILD_BUG_ON_ZERO((_min_len) == 0 ||                     \
516 					(_max_len) >                           \
517 						PAGE_SIZE / sizeof(void *) ||  \
518 					(_min_len) > (_max_len) ||             \
519 					(_access) == UVERBS_ACCESS_NEW ||      \
520 					(_access) == UVERBS_ACCESS_DESTROY),   \
521 		.attr = { .type = UVERBS_ATTR_TYPE_IDRS_ARRAY,                 \
522 			  .u2.objs_arr.obj_type = _idr_type,                   \
523 			  .u2.objs_arr.access = _access,                       \
524 			  .u2.objs_arr.min_len = _min_len,                     \
525 			  .u2.objs_arr.max_len = _max_len,                     \
526 			  __VA_ARGS__ } })
527 
528 /*
529  * Only for use with UVERBS_ATTR_IDR, allows any uobject type to be accepted,
530  * the user must validate the type of the uobject instead.
531  */
532 #define UVERBS_IDR_ANY_OBJECT 0xFFFF
533 
534 #define UVERBS_ATTR_IDR(_attr_id, _idr_type, _access, ...)                     \
535 	(&(const struct uverbs_attr_def){                                      \
536 		.id = _attr_id,                                                \
537 		.attr = { .type = UVERBS_ATTR_TYPE_IDR,                        \
538 			  .u.obj.obj_type = _idr_type,                         \
539 			  .u.obj.access = _access,                             \
540 			  __VA_ARGS__ } })
541 
542 #define UVERBS_ATTR_FD(_attr_id, _fd_type, _access, ...)                       \
543 	(&(const struct uverbs_attr_def){                                      \
544 		.id = (_attr_id) +                                             \
545 		      BUILD_BUG_ON_ZERO((_access) != UVERBS_ACCESS_NEW &&      \
546 					(_access) != UVERBS_ACCESS_READ),      \
547 		.attr = { .type = UVERBS_ATTR_TYPE_FD,                         \
548 			  .u.obj.obj_type = _fd_type,                          \
549 			  .u.obj.access = _access,                             \
550 			  __VA_ARGS__ } })
551 
552 #define UVERBS_ATTR_PTR_IN(_attr_id, _type, ...)                               \
553 	(&(const struct uverbs_attr_def){                                      \
554 		.id = _attr_id,                                                \
555 		.attr = { .type = UVERBS_ATTR_TYPE_PTR_IN,                     \
556 			  _type,                                               \
557 			  __VA_ARGS__ } })
558 
559 #define UVERBS_ATTR_PTR_OUT(_attr_id, _type, ...)                              \
560 	(&(const struct uverbs_attr_def){                                      \
561 		.id = _attr_id,                                                \
562 		.attr = { .type = UVERBS_ATTR_TYPE_PTR_OUT,                    \
563 			  _type,                                               \
564 			  __VA_ARGS__ } })
565 
566 /* _enum_arry should be a 'static const union uverbs_attr_spec[]' */
567 #define UVERBS_ATTR_ENUM_IN(_attr_id, _enum_arr, ...)                          \
568 	(&(const struct uverbs_attr_def){                                      \
569 		.id = _attr_id,                                                \
570 		.attr = { .type = UVERBS_ATTR_TYPE_ENUM_IN,                    \
571 			  .u2.enum_def.ids = _enum_arr,                        \
572 			  .u.enum_def.num_elems = ARRAY_SIZE(_enum_arr),       \
573 			  __VA_ARGS__ },                                       \
574 	})
575 
576 /* An input value that is a member in the enum _enum_type. */
577 #define UVERBS_ATTR_CONST_IN(_attr_id, _enum_type, ...)                        \
578 	UVERBS_ATTR_PTR_IN(                                                    \
579 		_attr_id,                                                      \
580 		UVERBS_ATTR_SIZE(                                              \
581 			sizeof(u64) + BUILD_BUG_ON_ZERO(!sizeof(_enum_type)),  \
582 			sizeof(u64)),                                          \
583 		__VA_ARGS__)
584 
585 /*
586  * An input value that is a bitwise combination of values of _enum_type.
587  * This permits the flag value to be passed as either a u32 or u64, it must
588  * be retrieved via uverbs_get_flag().
589  */
590 #define UVERBS_ATTR_FLAGS_IN(_attr_id, _enum_type, ...)                        \
591 	UVERBS_ATTR_PTR_IN(                                                    \
592 		_attr_id,                                                      \
593 		UVERBS_ATTR_SIZE(sizeof(u32) + BUILD_BUG_ON_ZERO(              \
594 						       !sizeof(_enum_type *)), \
595 				 sizeof(u64)),                                 \
596 		__VA_ARGS__)
597 
598 /*
599  * This spec is used in order to pass information to the hardware driver in a
600  * legacy way. Every verb that could get driver specific data should get this
601  * spec.
602  */
603 #define UVERBS_ATTR_UHW()                                                      \
604 	UVERBS_ATTR_PTR_IN(UVERBS_ATTR_UHW_IN,                                 \
605 			   UVERBS_ATTR_MIN_SIZE(0),			       \
606 			   UA_OPTIONAL,                                        \
607 			   .is_udata = 1),				       \
608 	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_UHW_OUT,                               \
609 			    UVERBS_ATTR_MIN_SIZE(0),			       \
610 			    UA_OPTIONAL,                                       \
611 			    .is_udata = 1)
612 
613 /* =================================================
614  *              Parsing infrastructure
615  * =================================================
616  */
617 
618 
619 struct uverbs_ptr_attr {
620 	/*
621 	 * If UVERBS_ATTR_SPEC_F_ALLOC_AND_COPY is set then the 'ptr' is
622 	 * used.
623 	 */
624 	union {
625 		void *ptr;
626 		u64 data;
627 	};
628 	u16		len;
629 	u16		uattr_idx;
630 	u8		enum_id;
631 };
632 
633 struct uverbs_obj_attr {
634 	struct ib_uobject		*uobject;
635 	const struct uverbs_api_attr	*attr_elm;
636 };
637 
638 struct uverbs_objs_arr_attr {
639 	struct ib_uobject **uobjects;
640 	u16 len;
641 };
642 
643 struct uverbs_attr {
644 	union {
645 		struct uverbs_ptr_attr	ptr_attr;
646 		struct uverbs_obj_attr	obj_attr;
647 		struct uverbs_objs_arr_attr objs_arr_attr;
648 	};
649 };
650 
651 struct uverbs_attr_bundle {
652 	struct ib_udata driver_udata;
653 	struct ib_udata ucore;
654 	struct ib_uverbs_file *ufile;
655 	struct ib_ucontext *context;
656 	DECLARE_BITMAP(attr_present, UVERBS_API_ATTR_BKEY_LEN);
657 	struct uverbs_attr attrs[];
658 };
659 
660 static inline bool uverbs_attr_is_valid(const struct uverbs_attr_bundle *attrs_bundle,
661 					unsigned int idx)
662 {
663 	return test_bit(uapi_bkey_attr(uapi_key_attr(idx)),
664 			attrs_bundle->attr_present);
665 }
666 
667 /**
668  * rdma_udata_to_drv_context - Helper macro to get the driver's context out of
669  *                             ib_udata which is embedded in uverbs_attr_bundle.
670  *
671  * If udata is not NULL this cannot fail. Otherwise a NULL udata will result
672  * in a NULL ucontext pointer, as a safety precaution. Callers should be using
673  * 'udata' to determine if the driver call is in user or kernel mode, not
674  * 'ucontext'.
675  *
676  */
677 #define rdma_udata_to_drv_context(udata, drv_dev_struct, member)               \
678 	(udata ? container_of(container_of(udata, struct uverbs_attr_bundle,   \
679 					   driver_udata)                       \
680 				      ->context,                               \
681 			      drv_dev_struct, member) :                        \
682 		 (drv_dev_struct *)NULL)
683 
684 #define IS_UVERBS_COPY_ERR(_ret)		((_ret) && (_ret) != -ENOENT)
685 
686 static inline const struct uverbs_attr *uverbs_attr_get(const struct uverbs_attr_bundle *attrs_bundle,
687 							u16 idx)
688 {
689 	if (!uverbs_attr_is_valid(attrs_bundle, idx))
690 		return ERR_PTR(-ENOENT);
691 
692 	return &attrs_bundle->attrs[uapi_bkey_attr(uapi_key_attr(idx))];
693 }
694 
695 static inline int uverbs_attr_get_enum_id(const struct uverbs_attr_bundle *attrs_bundle,
696 					  u16 idx)
697 {
698 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
699 
700 	if (IS_ERR(attr))
701 		return PTR_ERR(attr);
702 
703 	return attr->ptr_attr.enum_id;
704 }
705 
706 static inline void *uverbs_attr_get_obj(const struct uverbs_attr_bundle *attrs_bundle,
707 					u16 idx)
708 {
709 	const struct uverbs_attr *attr;
710 
711 	attr = uverbs_attr_get(attrs_bundle, idx);
712 	if (IS_ERR(attr))
713 		return ERR_CAST(attr);
714 
715 	return attr->obj_attr.uobject->object;
716 }
717 
718 static inline struct ib_uobject *uverbs_attr_get_uobject(const struct uverbs_attr_bundle *attrs_bundle,
719 							 u16 idx)
720 {
721 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
722 
723 	if (IS_ERR(attr))
724 		return ERR_CAST(attr);
725 
726 	return attr->obj_attr.uobject;
727 }
728 
729 static inline int
730 uverbs_attr_get_len(const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
731 {
732 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
733 
734 	if (IS_ERR(attr))
735 		return PTR_ERR(attr);
736 
737 	return attr->ptr_attr.len;
738 }
739 
740 /*
741  * uverbs_attr_ptr_get_array_size() - Get array size pointer by a ptr
742  * attribute.
743  * @attrs: The attribute bundle
744  * @idx: The ID of the attribute
745  * @elem_size: The size of the element in the array
746  */
747 static inline int
748 uverbs_attr_ptr_get_array_size(struct uverbs_attr_bundle *attrs, u16 idx,
749 			       size_t elem_size)
750 {
751 	int size = uverbs_attr_get_len(attrs, idx);
752 
753 	if (size < 0)
754 		return size;
755 
756 	if (size % elem_size)
757 		return -EINVAL;
758 
759 	return size / elem_size;
760 }
761 
762 /**
763  * uverbs_attr_get_uobjs_arr() - Provides array's properties for attribute for
764  * UVERBS_ATTR_TYPE_IDRS_ARRAY.
765  * @arr: Returned pointer to array of pointers for uobjects or NULL if
766  *       the attribute isn't provided.
767  *
768  * Return: The array length or 0 if no attribute was provided.
769  */
770 static inline int uverbs_attr_get_uobjs_arr(
771 	const struct uverbs_attr_bundle *attrs_bundle, u16 attr_idx,
772 	struct ib_uobject ***arr)
773 {
774 	const struct uverbs_attr *attr =
775 			uverbs_attr_get(attrs_bundle, attr_idx);
776 
777 	if (IS_ERR(attr)) {
778 		*arr = NULL;
779 		return 0;
780 	}
781 
782 	*arr = attr->objs_arr_attr.uobjects;
783 
784 	return attr->objs_arr_attr.len;
785 }
786 
787 static inline bool uverbs_attr_ptr_is_inline(const struct uverbs_attr *attr)
788 {
789 	return attr->ptr_attr.len <= sizeof(attr->ptr_attr.data);
790 }
791 
792 static inline void *uverbs_attr_get_alloced_ptr(
793 	const struct uverbs_attr_bundle *attrs_bundle, u16 idx)
794 {
795 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
796 
797 	if (IS_ERR(attr))
798 		return (void *)attr;
799 
800 	return uverbs_attr_ptr_is_inline(attr) ? (void *)&attr->ptr_attr.data :
801 						 attr->ptr_attr.ptr;
802 }
803 
804 static inline int _uverbs_copy_from(void *to,
805 				    const struct uverbs_attr_bundle *attrs_bundle,
806 				    size_t idx,
807 				    size_t size)
808 {
809 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
810 
811 	if (IS_ERR(attr))
812 		return PTR_ERR(attr);
813 
814 	/*
815 	 * Validation ensures attr->ptr_attr.len >= size. If the caller is
816 	 * using UVERBS_ATTR_SPEC_F_MIN_SZ_OR_ZERO then it must call
817 	 * uverbs_copy_from_or_zero.
818 	 */
819 	if (unlikely(size < attr->ptr_attr.len))
820 		return -EINVAL;
821 
822 	if (uverbs_attr_ptr_is_inline(attr))
823 		memcpy(to, &attr->ptr_attr.data, attr->ptr_attr.len);
824 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
825 				attr->ptr_attr.len))
826 		return -EFAULT;
827 
828 	return 0;
829 }
830 
831 static inline int _uverbs_copy_from_or_zero(void *to,
832 					    const struct uverbs_attr_bundle *attrs_bundle,
833 					    size_t idx,
834 					    size_t size)
835 {
836 	const struct uverbs_attr *attr = uverbs_attr_get(attrs_bundle, idx);
837 	size_t min_size;
838 
839 	if (IS_ERR(attr))
840 		return PTR_ERR(attr);
841 
842 	min_size = min_t(size_t, size, attr->ptr_attr.len);
843 
844 	if (uverbs_attr_ptr_is_inline(attr))
845 		memcpy(to, &attr->ptr_attr.data, min_size);
846 	else if (copy_from_user(to, u64_to_user_ptr(attr->ptr_attr.data),
847 				min_size))
848 		return -EFAULT;
849 
850 	if (size > min_size)
851 		memset(to + min_size, 0, size - min_size);
852 
853 	return 0;
854 }
855 
856 #define uverbs_copy_from(to, attrs_bundle, idx)				      \
857 	_uverbs_copy_from(to, attrs_bundle, idx, sizeof(*to))
858 
859 #define uverbs_copy_from_or_zero(to, attrs_bundle, idx)			      \
860 	_uverbs_copy_from_or_zero(to, attrs_bundle, idx, sizeof(*to))
861 
862 static inline struct ib_ucontext *
863 ib_uverbs_get_ucontext(const struct uverbs_attr_bundle *attrs)
864 {
865 	return ib_uverbs_get_ucontext_file(attrs->ufile);
866 }
867 
868 #if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
869 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
870 		       size_t idx, u64 allowed_bits);
871 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
872 		       size_t idx, u64 allowed_bits);
873 int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle, size_t idx,
874 		   const void *from, size_t size);
875 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
876 			     gfp_t flags);
877 
878 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
879 					  size_t size)
880 {
881 	return _uverbs_alloc(bundle, size, GFP_KERNEL);
882 }
883 
884 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
885 					   size_t size)
886 {
887 	return _uverbs_alloc(bundle, size, GFP_KERNEL | __GFP_ZERO);
888 }
889 int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
890 		      size_t idx, s64 lower_bound, u64 upper_bound,
891 		      s64 *def_val);
892 int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
893 				  size_t idx, const void *from, size_t size);
894 #else
895 static inline int
896 uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
897 		   size_t idx, u64 allowed_bits)
898 {
899 	return -EINVAL;
900 }
901 static inline int
902 uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
903 		   size_t idx, u64 allowed_bits)
904 {
905 	return -EINVAL;
906 }
907 static inline int uverbs_copy_to(const struct uverbs_attr_bundle *attrs_bundle,
908 				 size_t idx, const void *from, size_t size)
909 {
910 	return -EINVAL;
911 }
912 static inline __malloc void *uverbs_alloc(struct uverbs_attr_bundle *bundle,
913 					  size_t size)
914 {
915 	return ERR_PTR(-EINVAL);
916 }
917 static inline __malloc void *uverbs_zalloc(struct uverbs_attr_bundle *bundle,
918 					   size_t size)
919 {
920 	return ERR_PTR(-EINVAL);
921 }
922 static inline int
923 _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
924 		  size_t idx, s64 lower_bound, u64 upper_bound,
925 		  s64 *def_val)
926 {
927 	return -EINVAL;
928 }
929 static inline int
930 uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
931 			      size_t idx, const void *from, size_t size)
932 {
933 	return -EINVAL;
934 }
935 #endif
936 
937 #define uverbs_get_const(_to, _attrs_bundle, _idx)                             \
938 	({                                                                     \
939 		s64 _val;                                                      \
940 		int _ret = _uverbs_get_const(&_val, _attrs_bundle, _idx,       \
941 					     type_min(typeof(*_to)),           \
942 					     type_max(typeof(*_to)), NULL);    \
943 		(*_to) = _val;                                                 \
944 		_ret;                                                          \
945 	})
946 
947 #define uverbs_get_const_default(_to, _attrs_bundle, _idx, _default)           \
948 	({                                                                     \
949 		s64 _val;                                                      \
950 		s64 _def_val = _default;                                       \
951 		int _ret =                                                     \
952 			_uverbs_get_const(&_val, _attrs_bundle, _idx,          \
953 					  type_min(typeof(*_to)),              \
954 					  type_max(typeof(*_to)), &_def_val);  \
955 		(*_to) = _val;                                                 \
956 		_ret;                                                          \
957 	})
958 #endif
959