xref: /openbmc/u-boot/drivers/tee/optee/core.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2018 Linaro Limited
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <log.h>
9 #include <tee.h>
10 #include <linux/arm-smccc.h>
11 #include <linux/io.h>
12 
13 #include "optee_smc.h"
14 #include "optee_msg.h"
15 #include "optee_private.h"
16 
17 #define PAGELIST_ENTRIES_PER_PAGE \
18 	((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)
19 
20 typedef void (optee_invoke_fn)(unsigned long, unsigned long, unsigned long,
21 			       unsigned long, unsigned long, unsigned long,
22 			       unsigned long, unsigned long,
23 			       struct arm_smccc_res *);
24 
25 struct optee_pdata {
26 	optee_invoke_fn *invoke_fn;
27 };
28 
29 struct rpc_param {
30 	u32	a0;
31 	u32	a1;
32 	u32	a2;
33 	u32	a3;
34 	u32	a4;
35 	u32	a5;
36 	u32	a6;
37 	u32	a7;
38 };
39 
40 /**
41  * reg_pair_to_ptr() - Make a pointer of 2 32-bit values
42  * @reg0:	High bits of the pointer
43  * @reg1:	Low bits of the pointer
44  *
45  * Returns the combined result, note that if a pointer is 32-bit wide @reg0
46  * will be discarded.
47  */
48 static void *reg_pair_to_ptr(u32 reg0, u32 reg1)
49 {
50 	return (void *)(ulong)(((u64)reg0 << 32) | reg1);
51 }
52 
53 /**
54  * reg_pair_from_64() - Split a 64-bit value into two 32-bit values
55  * @reg0:	High bits of @val
56  * @reg1:	Low bits of @val
57  * @val:	The value to split
58  */
59 static void reg_pair_from_64(u32 *reg0, u32 *reg1, u64 val)
60 {
61 	*reg0 = val >> 32;
62 	*reg1 = val;
63 }
64 
65 /**
66  * optee_alloc_and_init_page_list() - Provide page list of memory buffer
67  * @buf:		Start of buffer
68  * @len:		Length of buffer
69  * @phys_buf_ptr	Physical pointer with coded offset to page list
70  *
71  * Secure world doesn't share mapping with Normal world (U-Boot in this case)
72  * so physical pointers are needed when sharing pointers.
73  *
74  * Returns a pointer page list on success or NULL on failure
75  */
76 void *optee_alloc_and_init_page_list(void *buf, ulong len, u64 *phys_buf_ptr)
77 {
78 	const unsigned int page_size = OPTEE_MSG_NONCONTIG_PAGE_SIZE;
79 	const phys_addr_t page_mask = page_size - 1;
80 	u8 *buf_base;
81 	unsigned int page_offset;
82 	unsigned int num_pages;
83 	unsigned int list_size;
84 	unsigned int n;
85 	void *page_list;
86 	struct {
87 		u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];
88 		u64 next_page_data;
89 	} *pages_data;
90 
91 	/*
92 	 * A Memory buffer is described in chunks of 4k. The list of
93 	 * physical addresses has to be represented by a physical pointer
94 	 * too and a single list has to start at a 4k page and fit into
95 	 * that page. In order to be able to describe large memory buffers
96 	 * these 4k pages carrying physical addresses are linked together
97 	 * in a list. See OPTEE_MSG_ATTR_NONCONTIG in
98 	 * drivers/tee/optee/optee_msg.h for more information.
99 	 */
100 
101 	page_offset = (ulong)buf & page_mask;
102 	num_pages = roundup(page_offset + len, page_size) / page_size;
103 	list_size = DIV_ROUND_UP(num_pages, PAGELIST_ENTRIES_PER_PAGE) *
104 		    page_size;
105 	page_list = memalign(page_size, list_size);
106 	if (!page_list)
107 		return NULL;
108 
109 	pages_data = page_list;
110 	buf_base = (u8 *)rounddown((ulong)buf, page_size);
111 	n = 0;
112 	while (num_pages) {
113 		pages_data->pages_list[n] = virt_to_phys(buf_base);
114 		n++;
115 		buf_base += page_size;
116 		num_pages--;
117 
118 		if (n == PAGELIST_ENTRIES_PER_PAGE) {
119 			pages_data->next_page_data =
120 				virt_to_phys(pages_data + 1);
121 			pages_data++;
122 			n = 0;
123 		}
124 	}
125 
126 	*phys_buf_ptr = virt_to_phys(page_list) | page_offset;
127 	return page_list;
128 }
129 
130 static void optee_get_version(struct udevice *dev,
131 			      struct tee_version_data *vers)
132 {
133 	struct tee_version_data v = {
134 		.gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM,
135 	};
136 
137 	*vers = v;
138 }
139 
140 static int get_msg_arg(struct udevice *dev, uint num_params,
141 		       struct tee_shm **shmp, struct optee_msg_arg **msg_arg)
142 {
143 	int rc;
144 	struct optee_msg_arg *ma;
145 
146 	rc = __tee_shm_add(dev, OPTEE_MSG_NONCONTIG_PAGE_SIZE, NULL,
147 			   OPTEE_MSG_GET_ARG_SIZE(num_params), TEE_SHM_ALLOC,
148 			   shmp);
149 	if (rc)
150 		return rc;
151 
152 	ma = (*shmp)->addr;
153 	memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
154 	ma->num_params = num_params;
155 	*msg_arg = ma;
156 
157 	return 0;
158 }
159 
160 static int to_msg_param(struct optee_msg_param *msg_params, uint num_params,
161 			const struct tee_param *params)
162 {
163 	uint n;
164 
165 	for (n = 0; n < num_params; n++) {
166 		const struct tee_param *p = params + n;
167 		struct optee_msg_param *mp = msg_params + n;
168 
169 		switch (p->attr) {
170 		case TEE_PARAM_ATTR_TYPE_NONE:
171 			mp->attr = OPTEE_MSG_ATTR_TYPE_NONE;
172 			memset(&mp->u, 0, sizeof(mp->u));
173 			break;
174 		case TEE_PARAM_ATTR_TYPE_VALUE_INPUT:
175 		case TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT:
176 		case TEE_PARAM_ATTR_TYPE_VALUE_INOUT:
177 			mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
178 				   TEE_PARAM_ATTR_TYPE_VALUE_INPUT;
179 			mp->u.value.a = p->u.value.a;
180 			mp->u.value.b = p->u.value.b;
181 			mp->u.value.c = p->u.value.c;
182 			break;
183 		case TEE_PARAM_ATTR_TYPE_MEMREF_INPUT:
184 		case TEE_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
185 		case TEE_PARAM_ATTR_TYPE_MEMREF_INOUT:
186 			mp->attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT + p->attr -
187 				   TEE_PARAM_ATTR_TYPE_MEMREF_INPUT;
188 			mp->u.rmem.shm_ref = (ulong)p->u.memref.shm;
189 			mp->u.rmem.size = p->u.memref.size;
190 			mp->u.rmem.offs = p->u.memref.shm_offs;
191 			break;
192 		default:
193 			return -EINVAL;
194 		}
195 	}
196 	return 0;
197 }
198 
199 static int from_msg_param(struct tee_param *params, uint num_params,
200 			  const struct optee_msg_param *msg_params)
201 {
202 	uint n;
203 	struct tee_shm *shm;
204 
205 	for (n = 0; n < num_params; n++) {
206 		struct tee_param *p = params + n;
207 		const struct optee_msg_param *mp = msg_params + n;
208 		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
209 
210 		switch (attr) {
211 		case OPTEE_MSG_ATTR_TYPE_NONE:
212 			p->attr = TEE_PARAM_ATTR_TYPE_NONE;
213 			memset(&p->u, 0, sizeof(p->u));
214 			break;
215 		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
216 		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
217 		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
218 			p->attr = TEE_PARAM_ATTR_TYPE_VALUE_INPUT + attr -
219 				  OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
220 			p->u.value.a = mp->u.value.a;
221 			p->u.value.b = mp->u.value.b;
222 			p->u.value.c = mp->u.value.c;
223 			break;
224 		case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
225 		case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
226 		case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
227 			p->attr = TEE_PARAM_ATTR_TYPE_MEMREF_INPUT + attr -
228 				  OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
229 			p->u.memref.size = mp->u.rmem.size;
230 			shm = (struct tee_shm *)(ulong)mp->u.rmem.shm_ref;
231 
232 			if (!shm) {
233 				p->u.memref.shm_offs = 0;
234 				p->u.memref.shm = NULL;
235 				break;
236 			}
237 			p->u.memref.shm_offs = mp->u.rmem.offs;
238 			p->u.memref.shm = shm;
239 			break;
240 		default:
241 			return -EINVAL;
242 		}
243 	}
244 	return 0;
245 }
246 
247 static void handle_rpc(struct udevice *dev, struct rpc_param *param,
248 		       void *page_list)
249 {
250 	struct tee_shm *shm;
251 
252 	switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
253 	case OPTEE_SMC_RPC_FUNC_ALLOC:
254 		if (!__tee_shm_add(dev, OPTEE_MSG_NONCONTIG_PAGE_SIZE, NULL,
255 				   param->a1, TEE_SHM_ALLOC | TEE_SHM_REGISTER,
256 				   &shm)) {
257 			reg_pair_from_64(&param->a1, &param->a2,
258 					 virt_to_phys(shm->addr));
259 			/* "cookie" */
260 			reg_pair_from_64(&param->a4, &param->a5, (ulong)shm);
261 		} else {
262 			param->a1 = 0;
263 			param->a2 = 0;
264 			param->a4 = 0;
265 			param->a5 = 0;
266 		}
267 		break;
268 	case OPTEE_SMC_RPC_FUNC_FREE:
269 		shm = reg_pair_to_ptr(param->a1, param->a2);
270 		tee_shm_free(shm);
271 		break;
272 	case OPTEE_SMC_RPC_FUNC_FOREIGN_INTR:
273 		break;
274 	case OPTEE_SMC_RPC_FUNC_CMD:
275 		shm = reg_pair_to_ptr(param->a1, param->a2);
276 		optee_suppl_cmd(dev, shm, page_list);
277 		break;
278 	default:
279 		break;
280 	}
281 
282 	param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
283 }
284 
285 static u32 call_err_to_res(u32 call_err)
286 {
287 	switch (call_err) {
288 	case OPTEE_SMC_RETURN_OK:
289 		return TEE_SUCCESS;
290 	default:
291 		return TEE_ERROR_BAD_PARAMETERS;
292 	}
293 }
294 
295 static u32 do_call_with_arg(struct udevice *dev, struct optee_msg_arg *arg)
296 {
297 	struct optee_pdata *pdata = dev_get_platdata(dev);
298 	struct rpc_param param = { .a0 = OPTEE_SMC_CALL_WITH_ARG };
299 	void *page_list = NULL;
300 
301 	reg_pair_from_64(&param.a1, &param.a2, virt_to_phys(arg));
302 	while (true) {
303 		struct arm_smccc_res res;
304 
305 		pdata->invoke_fn(param.a0, param.a1, param.a2, param.a3,
306 				 param.a4, param.a5, param.a6, param.a7, &res);
307 
308 		free(page_list);
309 		page_list = NULL;
310 
311 		if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) {
312 			param.a0 = res.a0;
313 			param.a1 = res.a1;
314 			param.a2 = res.a2;
315 			param.a3 = res.a3;
316 			handle_rpc(dev, &param, &page_list);
317 		} else {
318 			/*
319 			 * In case we've accessed RPMB to serve an RPC
320 			 * request we need to restore the previously
321 			 * selected partition as the caller may expect it
322 			 * to remain unchanged.
323 			 */
324 			optee_suppl_rpmb_release(dev);
325 			return call_err_to_res(res.a0);
326 		}
327 	}
328 }
329 
330 static int optee_close_session(struct udevice *dev, u32 session)
331 {
332 	int rc;
333 	struct tee_shm *shm;
334 	struct optee_msg_arg *msg_arg;
335 
336 	rc = get_msg_arg(dev, 0, &shm, &msg_arg);
337 	if (rc)
338 		return rc;
339 
340 	msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
341 	msg_arg->session = session;
342 	do_call_with_arg(dev, msg_arg);
343 
344 	tee_shm_free(shm);
345 
346 	return 0;
347 }
348 
349 static int optee_open_session(struct udevice *dev,
350 			      struct tee_open_session_arg *arg,
351 			      uint num_params, struct tee_param *params)
352 {
353 	int rc;
354 	struct tee_shm *shm;
355 	struct optee_msg_arg *msg_arg;
356 
357 	rc = get_msg_arg(dev, num_params + 2, &shm, &msg_arg);
358 	if (rc)
359 		return rc;
360 
361 	msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
362 	/*
363 	 * Initialize and add the meta parameters needed when opening a
364 	 * session.
365 	 */
366 	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
367 				  OPTEE_MSG_ATTR_META;
368 	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
369 				  OPTEE_MSG_ATTR_META;
370 	memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
371 	memcpy(&msg_arg->params[1].u.value, arg->uuid, sizeof(arg->clnt_uuid));
372 	msg_arg->params[1].u.value.c = arg->clnt_login;
373 
374 	rc = to_msg_param(msg_arg->params + 2, num_params, params);
375 	if (rc)
376 		goto out;
377 
378 	arg->ret = do_call_with_arg(dev, msg_arg);
379 	if (arg->ret) {
380 		arg->ret_origin = TEE_ORIGIN_COMMS;
381 		goto out;
382 	}
383 
384 	if (from_msg_param(params, num_params, msg_arg->params + 2)) {
385 		arg->ret = TEE_ERROR_COMMUNICATION;
386 		arg->ret_origin = TEE_ORIGIN_COMMS;
387 		/* Close session again to avoid leakage */
388 		optee_close_session(dev, msg_arg->session);
389 		goto out;
390 	}
391 
392 	arg->session = msg_arg->session;
393 	arg->ret = msg_arg->ret;
394 	arg->ret_origin = msg_arg->ret_origin;
395 out:
396 	tee_shm_free(shm);
397 
398 	return rc;
399 }
400 
401 static int optee_invoke_func(struct udevice *dev, struct tee_invoke_arg *arg,
402 			     uint num_params, struct tee_param *params)
403 {
404 	struct tee_shm *shm;
405 	struct optee_msg_arg *msg_arg;
406 	int rc;
407 
408 	rc = get_msg_arg(dev, num_params, &shm, &msg_arg);
409 	if (rc)
410 		return rc;
411 	msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
412 	msg_arg->func = arg->func;
413 	msg_arg->session = arg->session;
414 
415 	rc = to_msg_param(msg_arg->params, num_params, params);
416 	if (rc)
417 		goto out;
418 
419 	arg->ret = do_call_with_arg(dev, msg_arg);
420 	if (arg->ret) {
421 		arg->ret_origin = TEE_ORIGIN_COMMS;
422 		goto out;
423 	}
424 
425 	if (from_msg_param(params, num_params, msg_arg->params)) {
426 		arg->ret = TEE_ERROR_COMMUNICATION;
427 		arg->ret_origin = TEE_ORIGIN_COMMS;
428 		goto out;
429 	}
430 
431 	arg->ret = msg_arg->ret;
432 	arg->ret_origin = msg_arg->ret_origin;
433 out:
434 	tee_shm_free(shm);
435 	return rc;
436 }
437 
438 static int optee_shm_register(struct udevice *dev, struct tee_shm *shm)
439 {
440 	struct tee_shm *shm_arg;
441 	struct optee_msg_arg *msg_arg;
442 	void *pl;
443 	u64 ph_ptr;
444 	int rc;
445 
446 	rc = get_msg_arg(dev, 1, &shm_arg, &msg_arg);
447 	if (rc)
448 		return rc;
449 
450 	pl = optee_alloc_and_init_page_list(shm->addr, shm->size, &ph_ptr);
451 	if (!pl) {
452 		rc = -ENOMEM;
453 		goto out;
454 	}
455 
456 	msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
457 	msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
458 				OPTEE_MSG_ATTR_NONCONTIG;
459 	msg_arg->params->u.tmem.buf_ptr = ph_ptr;
460 	msg_arg->params->u.tmem.shm_ref = (ulong)shm;
461 	msg_arg->params->u.tmem.size = shm->size;
462 
463 	if (do_call_with_arg(dev, msg_arg) || msg_arg->ret)
464 		rc = -EINVAL;
465 
466 	free(pl);
467 out:
468 	tee_shm_free(shm_arg);
469 
470 	return rc;
471 }
472 
473 static int optee_shm_unregister(struct udevice *dev, struct tee_shm *shm)
474 {
475 	struct tee_shm *shm_arg;
476 	struct optee_msg_arg *msg_arg;
477 	int rc;
478 
479 	rc = get_msg_arg(dev, 1, &shm_arg, &msg_arg);
480 	if (rc)
481 		return rc;
482 
483 	msg_arg->cmd = OPTEE_MSG_CMD_UNREGISTER_SHM;
484 	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
485 	msg_arg->params[0].u.rmem.shm_ref = (ulong)shm;
486 
487 	if (do_call_with_arg(dev, msg_arg) || msg_arg->ret)
488 		rc = -EINVAL;
489 	tee_shm_free(shm_arg);
490 
491 	return rc;
492 }
493 
494 static const struct tee_driver_ops optee_ops = {
495 	.get_version = optee_get_version,
496 	.open_session = optee_open_session,
497 	.close_session = optee_close_session,
498 	.invoke_func = optee_invoke_func,
499 	.shm_register = optee_shm_register,
500 	.shm_unregister = optee_shm_unregister,
501 };
502 
503 static bool is_optee_api(optee_invoke_fn *invoke_fn)
504 {
505 	struct arm_smccc_res res;
506 
507 	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);
508 
509 	return res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
510 	       res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3;
511 }
512 
513 static void print_os_revision(optee_invoke_fn *invoke_fn)
514 {
515 	union {
516 		struct arm_smccc_res smccc;
517 		struct optee_smc_call_get_os_revision_result result;
518 	} res = {
519 		.result = {
520 		.build_id = 0
521 		}
522 	};
523 
524 	invoke_fn(OPTEE_SMC_CALL_GET_OS_REVISION, 0, 0, 0, 0, 0, 0, 0,
525 		  &res.smccc);
526 
527 	if (res.result.build_id)
528 		debug("OP-TEE revision %lu.%lu (%08lx)\n", res.result.major,
529 		      res.result.minor, res.result.build_id);
530 	else
531 		debug("OP-TEE revision %lu.%lu\n", res.result.major,
532 		      res.result.minor);
533 }
534 
535 static bool api_revision_is_compatible(optee_invoke_fn *invoke_fn)
536 {
537 	union {
538 		struct arm_smccc_res smccc;
539 		struct optee_smc_calls_revision_result result;
540 	} res;
541 
542 	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
543 
544 	return res.result.major == OPTEE_MSG_REVISION_MAJOR &&
545 	       (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR;
546 }
547 
548 static bool exchange_capabilities(optee_invoke_fn *invoke_fn, u32 *sec_caps)
549 {
550 	union {
551 		struct arm_smccc_res smccc;
552 		struct optee_smc_exchange_capabilities_result result;
553 	} res;
554 
555 	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES,
556 		  OPTEE_SMC_NSEC_CAP_UNIPROCESSOR, 0, 0, 0, 0, 0, 0,
557 		  &res.smccc);
558 
559 	if (res.result.status != OPTEE_SMC_RETURN_OK)
560 		return false;
561 
562 	*sec_caps = res.result.capabilities;
563 
564 	return true;
565 }
566 
567 /* Simple wrapper functions to be able to use a function pointer */
568 static void optee_smccc_smc(unsigned long a0, unsigned long a1,
569 			    unsigned long a2, unsigned long a3,
570 			    unsigned long a4, unsigned long a5,
571 			    unsigned long a6, unsigned long a7,
572 			    struct arm_smccc_res *res)
573 {
574 	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
575 }
576 
577 static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
578 			    unsigned long a2, unsigned long a3,
579 			    unsigned long a4, unsigned long a5,
580 			    unsigned long a6, unsigned long a7,
581 			    struct arm_smccc_res *res)
582 {
583 	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
584 }
585 
586 static optee_invoke_fn *get_invoke_func(struct udevice *dev)
587 {
588 	const char *method;
589 
590 	debug("optee: looking for conduit method in DT.\n");
591 	method = ofnode_get_property(dev->node, "method", NULL);
592 	if (!method) {
593 		debug("optee: missing \"method\" property\n");
594 		return ERR_PTR(-ENXIO);
595 	}
596 
597 	if (!strcmp("hvc", method))
598 		return optee_smccc_hvc;
599 	else if (!strcmp("smc", method))
600 		return optee_smccc_smc;
601 
602 	debug("optee: invalid \"method\" property: %s\n", method);
603 	return ERR_PTR(-EINVAL);
604 }
605 
606 static int optee_ofdata_to_platdata(struct udevice *dev)
607 {
608 	struct optee_pdata *pdata = dev_get_platdata(dev);
609 
610 	pdata->invoke_fn = get_invoke_func(dev);
611 	if (IS_ERR(pdata->invoke_fn))
612 		return PTR_ERR(pdata->invoke_fn);
613 
614 	return 0;
615 }
616 
617 static int optee_probe(struct udevice *dev)
618 {
619 	struct optee_pdata *pdata = dev_get_platdata(dev);
620 	u32 sec_caps;
621 
622 	if (!is_optee_api(pdata->invoke_fn)) {
623 		debug("%s: OP-TEE api uid mismatch\n", __func__);
624 		return -ENOENT;
625 	}
626 
627 	print_os_revision(pdata->invoke_fn);
628 
629 	if (!api_revision_is_compatible(pdata->invoke_fn)) {
630 		debug("%s: OP-TEE api revision mismatch\n", __func__);
631 		return -ENOENT;
632 	}
633 
634 	/*
635 	 * OP-TEE can use both shared memory via predefined pool or as
636 	 * dynamic shared memory provided by normal world. To keep things
637 	 * simple we're only using dynamic shared memory in this driver.
638 	 */
639 	if (!exchange_capabilities(pdata->invoke_fn, &sec_caps) ||
640 	    !(sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)) {
641 		debug("%s: OP-TEE capabilities mismatch\n", __func__);
642 		return -ENOENT;
643 	}
644 
645 	return 0;
646 }
647 
648 static const struct udevice_id optee_match[] = {
649 	{ .compatible = "linaro,optee-tz" },
650 	{},
651 };
652 
653 U_BOOT_DRIVER(optee) = {
654 	.name = "optee",
655 	.id = UCLASS_TEE,
656 	.of_match = optee_match,
657 	.ofdata_to_platdata = optee_ofdata_to_platdata,
658 	.probe = optee_probe,
659 	.ops = &optee_ops,
660 	.platdata_auto_alloc_size = sizeof(struct optee_pdata),
661 	.priv_auto_alloc_size = sizeof(struct optee_private),
662 };
663