xref: /openbmc/linux/drivers/tee/optee/ffa_abi.c (revision d47a97bd)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2021, Linaro Limited
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/arm_ffa.h>
9 #include <linux/errno.h>
10 #include <linux/scatterlist.h>
11 #include <linux/sched.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
14 #include <linux/tee_drv.h>
15 #include <linux/types.h>
16 #include "optee_private.h"
17 #include "optee_ffa.h"
18 #include "optee_rpc_cmd.h"
19 
20 /*
21  * This file implement the FF-A ABI used when communicating with secure world
22  * OP-TEE OS via FF-A.
23  * This file is divided into the following sections:
24  * 1. Maintain a hash table for lookup of a global FF-A memory handle
25  * 2. Convert between struct tee_param and struct optee_msg_param
26  * 3. Low level support functions to register shared memory in secure world
27  * 4. Dynamic shared memory pool based on alloc_pages()
28  * 5. Do a normal scheduled call into secure world
29  * 6. Driver initialization.
30  */
31 
32 /*
33  * 1. Maintain a hash table for lookup of a global FF-A memory handle
34  *
35  * FF-A assigns a global memory handle for each piece shared memory.
36  * This handle is then used when communicating with secure world.
37  *
38  * Main functions are optee_shm_add_ffa_handle() and optee_shm_rem_ffa_handle()
39  */
40 struct shm_rhash {
41 	struct tee_shm *shm;
42 	u64 global_id;
43 	struct rhash_head linkage;
44 };
45 
46 static void rh_free_fn(void *ptr, void *arg)
47 {
48 	kfree(ptr);
49 }
50 
51 static const struct rhashtable_params shm_rhash_params = {
52 	.head_offset = offsetof(struct shm_rhash, linkage),
53 	.key_len     = sizeof(u64),
54 	.key_offset  = offsetof(struct shm_rhash, global_id),
55 	.automatic_shrinking = true,
56 };
57 
58 static struct tee_shm *optee_shm_from_ffa_handle(struct optee *optee,
59 						 u64 global_id)
60 {
61 	struct tee_shm *shm = NULL;
62 	struct shm_rhash *r;
63 
64 	mutex_lock(&optee->ffa.mutex);
65 	r = rhashtable_lookup_fast(&optee->ffa.global_ids, &global_id,
66 				   shm_rhash_params);
67 	if (r)
68 		shm = r->shm;
69 	mutex_unlock(&optee->ffa.mutex);
70 
71 	return shm;
72 }
73 
74 static int optee_shm_add_ffa_handle(struct optee *optee, struct tee_shm *shm,
75 				    u64 global_id)
76 {
77 	struct shm_rhash *r;
78 	int rc;
79 
80 	r = kmalloc(sizeof(*r), GFP_KERNEL);
81 	if (!r)
82 		return -ENOMEM;
83 	r->shm = shm;
84 	r->global_id = global_id;
85 
86 	mutex_lock(&optee->ffa.mutex);
87 	rc = rhashtable_lookup_insert_fast(&optee->ffa.global_ids, &r->linkage,
88 					   shm_rhash_params);
89 	mutex_unlock(&optee->ffa.mutex);
90 
91 	if (rc)
92 		kfree(r);
93 
94 	return rc;
95 }
96 
97 static int optee_shm_rem_ffa_handle(struct optee *optee, u64 global_id)
98 {
99 	struct shm_rhash *r;
100 	int rc = -ENOENT;
101 
102 	mutex_lock(&optee->ffa.mutex);
103 	r = rhashtable_lookup_fast(&optee->ffa.global_ids, &global_id,
104 				   shm_rhash_params);
105 	if (r)
106 		rc = rhashtable_remove_fast(&optee->ffa.global_ids,
107 					    &r->linkage, shm_rhash_params);
108 	mutex_unlock(&optee->ffa.mutex);
109 
110 	if (!rc)
111 		kfree(r);
112 
113 	return rc;
114 }
115 
116 /*
117  * 2. Convert between struct tee_param and struct optee_msg_param
118  *
119  * optee_ffa_from_msg_param() and optee_ffa_to_msg_param() are the main
120  * functions.
121  */
122 
123 static void from_msg_param_ffa_mem(struct optee *optee, struct tee_param *p,
124 				   u32 attr, const struct optee_msg_param *mp)
125 {
126 	struct tee_shm *shm = NULL;
127 	u64 offs_high = 0;
128 	u64 offs_low = 0;
129 
130 	p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
131 		  attr - OPTEE_MSG_ATTR_TYPE_FMEM_INPUT;
132 	p->u.memref.size = mp->u.fmem.size;
133 
134 	if (mp->u.fmem.global_id != OPTEE_MSG_FMEM_INVALID_GLOBAL_ID)
135 		shm = optee_shm_from_ffa_handle(optee, mp->u.fmem.global_id);
136 	p->u.memref.shm = shm;
137 
138 	if (shm) {
139 		offs_low = mp->u.fmem.offs_low;
140 		offs_high = mp->u.fmem.offs_high;
141 	}
142 	p->u.memref.shm_offs = offs_low | offs_high << 32;
143 }
144 
145 /**
146  * optee_ffa_from_msg_param() - convert from OPTEE_MSG parameters to
147  *				struct tee_param
148  * @optee:	main service struct
149  * @params:	subsystem internal parameter representation
150  * @num_params:	number of elements in the parameter arrays
151  * @msg_params:	OPTEE_MSG parameters
152  *
153  * Returns 0 on success or <0 on failure
154  */
155 static int optee_ffa_from_msg_param(struct optee *optee,
156 				    struct tee_param *params, size_t num_params,
157 				    const struct optee_msg_param *msg_params)
158 {
159 	size_t n;
160 
161 	for (n = 0; n < num_params; n++) {
162 		struct tee_param *p = params + n;
163 		const struct optee_msg_param *mp = msg_params + n;
164 		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
165 
166 		switch (attr) {
167 		case OPTEE_MSG_ATTR_TYPE_NONE:
168 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
169 			memset(&p->u, 0, sizeof(p->u));
170 			break;
171 		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
172 		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
173 		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
174 			optee_from_msg_param_value(p, attr, mp);
175 			break;
176 		case OPTEE_MSG_ATTR_TYPE_FMEM_INPUT:
177 		case OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT:
178 		case OPTEE_MSG_ATTR_TYPE_FMEM_INOUT:
179 			from_msg_param_ffa_mem(optee, p, attr, mp);
180 			break;
181 		default:
182 			return -EINVAL;
183 		}
184 	}
185 
186 	return 0;
187 }
188 
189 static int to_msg_param_ffa_mem(struct optee_msg_param *mp,
190 				const struct tee_param *p)
191 {
192 	struct tee_shm *shm = p->u.memref.shm;
193 
194 	mp->attr = OPTEE_MSG_ATTR_TYPE_FMEM_INPUT + p->attr -
195 		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
196 
197 	if (shm) {
198 		u64 shm_offs = p->u.memref.shm_offs;
199 
200 		mp->u.fmem.internal_offs = shm->offset;
201 
202 		mp->u.fmem.offs_low = shm_offs;
203 		mp->u.fmem.offs_high = shm_offs >> 32;
204 		/* Check that the entire offset could be stored. */
205 		if (mp->u.fmem.offs_high != shm_offs >> 32)
206 			return -EINVAL;
207 
208 		mp->u.fmem.global_id = shm->sec_world_id;
209 	} else {
210 		memset(&mp->u, 0, sizeof(mp->u));
211 		mp->u.fmem.global_id = OPTEE_MSG_FMEM_INVALID_GLOBAL_ID;
212 	}
213 	mp->u.fmem.size = p->u.memref.size;
214 
215 	return 0;
216 }
217 
218 /**
219  * optee_ffa_to_msg_param() - convert from struct tee_params to OPTEE_MSG
220  *			      parameters
221  * @optee:	main service struct
222  * @msg_params:	OPTEE_MSG parameters
223  * @num_params:	number of elements in the parameter arrays
224  * @params:	subsystem itnernal parameter representation
225  * Returns 0 on success or <0 on failure
226  */
227 static int optee_ffa_to_msg_param(struct optee *optee,
228 				  struct optee_msg_param *msg_params,
229 				  size_t num_params,
230 				  const struct tee_param *params)
231 {
232 	size_t n;
233 
234 	for (n = 0; n < num_params; n++) {
235 		const struct tee_param *p = params + n;
236 		struct optee_msg_param *mp = msg_params + n;
237 
238 		switch (p->attr) {
239 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
240 			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
241 			memset(&mp->u, 0, sizeof(mp->u));
242 			break;
243 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
244 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
245 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
246 			optee_to_msg_param_value(mp, p);
247 			break;
248 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
249 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
250 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
251 			if (to_msg_param_ffa_mem(mp, p))
252 				return -EINVAL;
253 			break;
254 		default:
255 			return -EINVAL;
256 		}
257 	}
258 
259 	return 0;
260 }
261 
262 /*
263  * 3. Low level support functions to register shared memory in secure world
264  *
265  * Functions to register and unregister shared memory both for normal
266  * clients and for tee-supplicant.
267  */
268 
269 static int optee_ffa_shm_register(struct tee_context *ctx, struct tee_shm *shm,
270 				  struct page **pages, size_t num_pages,
271 				  unsigned long start)
272 {
273 	struct optee *optee = tee_get_drvdata(ctx->teedev);
274 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
275 	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
276 	struct ffa_mem_region_attributes mem_attr = {
277 		.receiver = ffa_dev->vm_id,
278 		.attrs = FFA_MEM_RW,
279 	};
280 	struct ffa_mem_ops_args args = {
281 		.use_txbuf = true,
282 		.attrs = &mem_attr,
283 		.nattrs = 1,
284 	};
285 	struct sg_table sgt;
286 	int rc;
287 
288 	rc = optee_check_mem_type(start, num_pages);
289 	if (rc)
290 		return rc;
291 
292 	rc = sg_alloc_table_from_pages(&sgt, pages, num_pages, 0,
293 				       num_pages * PAGE_SIZE, GFP_KERNEL);
294 	if (rc)
295 		return rc;
296 	args.sg = sgt.sgl;
297 	rc = mem_ops->memory_share(&args);
298 	sg_free_table(&sgt);
299 	if (rc)
300 		return rc;
301 
302 	rc = optee_shm_add_ffa_handle(optee, shm, args.g_handle);
303 	if (rc) {
304 		mem_ops->memory_reclaim(args.g_handle, 0);
305 		return rc;
306 	}
307 
308 	shm->sec_world_id = args.g_handle;
309 
310 	return 0;
311 }
312 
313 static int optee_ffa_shm_unregister(struct tee_context *ctx,
314 				    struct tee_shm *shm)
315 {
316 	struct optee *optee = tee_get_drvdata(ctx->teedev);
317 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
318 	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
319 	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
320 	u64 global_handle = shm->sec_world_id;
321 	struct ffa_send_direct_data data = {
322 		.data0 = OPTEE_FFA_UNREGISTER_SHM,
323 		.data1 = (u32)global_handle,
324 		.data2 = (u32)(global_handle >> 32)
325 	};
326 	int rc;
327 
328 	optee_shm_rem_ffa_handle(optee, global_handle);
329 	shm->sec_world_id = 0;
330 
331 	rc = msg_ops->sync_send_receive(ffa_dev, &data);
332 	if (rc)
333 		pr_err("Unregister SHM id 0x%llx rc %d\n", global_handle, rc);
334 
335 	rc = mem_ops->memory_reclaim(global_handle, 0);
336 	if (rc)
337 		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
338 
339 	return rc;
340 }
341 
342 static int optee_ffa_shm_unregister_supp(struct tee_context *ctx,
343 					 struct tee_shm *shm)
344 {
345 	struct optee *optee = tee_get_drvdata(ctx->teedev);
346 	const struct ffa_mem_ops *mem_ops;
347 	u64 global_handle = shm->sec_world_id;
348 	int rc;
349 
350 	/*
351 	 * We're skipping the OPTEE_FFA_YIELDING_CALL_UNREGISTER_SHM call
352 	 * since this is OP-TEE freeing via RPC so it has already retired
353 	 * this ID.
354 	 */
355 
356 	optee_shm_rem_ffa_handle(optee, global_handle);
357 	mem_ops = optee->ffa.ffa_dev->ops->mem_ops;
358 	rc = mem_ops->memory_reclaim(global_handle, 0);
359 	if (rc)
360 		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
361 
362 	shm->sec_world_id = 0;
363 
364 	return rc;
365 }
366 
367 /*
368  * 4. Dynamic shared memory pool based on alloc_pages()
369  *
370  * Implements an OP-TEE specific shared memory pool.
371  * The main function is optee_ffa_shm_pool_alloc_pages().
372  */
373 
374 static int pool_ffa_op_alloc(struct tee_shm_pool *pool,
375 			     struct tee_shm *shm, size_t size, size_t align)
376 {
377 	return optee_pool_op_alloc_helper(pool, shm, size, align,
378 					  optee_ffa_shm_register);
379 }
380 
381 static void pool_ffa_op_free(struct tee_shm_pool *pool,
382 			     struct tee_shm *shm)
383 {
384 	optee_pool_op_free_helper(pool, shm, optee_ffa_shm_unregister);
385 }
386 
387 static void pool_ffa_op_destroy_pool(struct tee_shm_pool *pool)
388 {
389 	kfree(pool);
390 }
391 
392 static const struct tee_shm_pool_ops pool_ffa_ops = {
393 	.alloc = pool_ffa_op_alloc,
394 	.free = pool_ffa_op_free,
395 	.destroy_pool = pool_ffa_op_destroy_pool,
396 };
397 
398 /**
399  * optee_ffa_shm_pool_alloc_pages() - create page-based allocator pool
400  *
401  * This pool is used with OP-TEE over FF-A. In this case command buffers
402  * and such are allocated from kernel's own memory.
403  */
404 static struct tee_shm_pool *optee_ffa_shm_pool_alloc_pages(void)
405 {
406 	struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
407 
408 	if (!pool)
409 		return ERR_PTR(-ENOMEM);
410 
411 	pool->ops = &pool_ffa_ops;
412 
413 	return pool;
414 }
415 
416 /*
417  * 5. Do a normal scheduled call into secure world
418  *
419  * The function optee_ffa_do_call_with_arg() performs a normal scheduled
420  * call into secure world. During this call may normal world request help
421  * from normal world using RPCs, Remote Procedure Calls. This includes
422  * delivery of non-secure interrupts to for instance allow rescheduling of
423  * the current task.
424  */
425 
426 static void handle_ffa_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
427 					      struct optee *optee,
428 					      struct optee_msg_arg *arg)
429 {
430 	struct tee_shm *shm;
431 
432 	if (arg->num_params != 1 ||
433 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
434 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
435 		return;
436 	}
437 
438 	switch (arg->params[0].u.value.a) {
439 	case OPTEE_RPC_SHM_TYPE_APPL:
440 		shm = optee_rpc_cmd_alloc_suppl(ctx, arg->params[0].u.value.b);
441 		break;
442 	case OPTEE_RPC_SHM_TYPE_KERNEL:
443 		shm = tee_shm_alloc_priv_buf(optee->ctx,
444 					     arg->params[0].u.value.b);
445 		break;
446 	default:
447 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
448 		return;
449 	}
450 
451 	if (IS_ERR(shm)) {
452 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
453 		return;
454 	}
455 
456 	arg->params[0] = (struct optee_msg_param){
457 		.attr = OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT,
458 		.u.fmem.size = tee_shm_get_size(shm),
459 		.u.fmem.global_id = shm->sec_world_id,
460 		.u.fmem.internal_offs = shm->offset,
461 	};
462 
463 	arg->ret = TEEC_SUCCESS;
464 }
465 
466 static void handle_ffa_rpc_func_cmd_shm_free(struct tee_context *ctx,
467 					     struct optee *optee,
468 					     struct optee_msg_arg *arg)
469 {
470 	struct tee_shm *shm;
471 
472 	if (arg->num_params != 1 ||
473 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
474 		goto err_bad_param;
475 
476 	shm = optee_shm_from_ffa_handle(optee, arg->params[0].u.value.b);
477 	if (!shm)
478 		goto err_bad_param;
479 	switch (arg->params[0].u.value.a) {
480 	case OPTEE_RPC_SHM_TYPE_APPL:
481 		optee_rpc_cmd_free_suppl(ctx, shm);
482 		break;
483 	case OPTEE_RPC_SHM_TYPE_KERNEL:
484 		tee_shm_free(shm);
485 		break;
486 	default:
487 		goto err_bad_param;
488 	}
489 	arg->ret = TEEC_SUCCESS;
490 	return;
491 
492 err_bad_param:
493 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
494 }
495 
496 static void handle_ffa_rpc_func_cmd(struct tee_context *ctx,
497 				    struct optee *optee,
498 				    struct optee_msg_arg *arg)
499 {
500 	arg->ret_origin = TEEC_ORIGIN_COMMS;
501 	switch (arg->cmd) {
502 	case OPTEE_RPC_CMD_SHM_ALLOC:
503 		handle_ffa_rpc_func_cmd_shm_alloc(ctx, optee, arg);
504 		break;
505 	case OPTEE_RPC_CMD_SHM_FREE:
506 		handle_ffa_rpc_func_cmd_shm_free(ctx, optee, arg);
507 		break;
508 	default:
509 		optee_rpc_cmd(ctx, optee, arg);
510 	}
511 }
512 
513 static void optee_handle_ffa_rpc(struct tee_context *ctx, struct optee *optee,
514 				 u32 cmd, struct optee_msg_arg *arg)
515 {
516 	switch (cmd) {
517 	case OPTEE_FFA_YIELDING_CALL_RETURN_RPC_CMD:
518 		handle_ffa_rpc_func_cmd(ctx, optee, arg);
519 		break;
520 	case OPTEE_FFA_YIELDING_CALL_RETURN_INTERRUPT:
521 		/* Interrupt delivered by now */
522 		break;
523 	default:
524 		pr_warn("Unknown RPC func 0x%x\n", cmd);
525 		break;
526 	}
527 }
528 
529 static int optee_ffa_yielding_call(struct tee_context *ctx,
530 				   struct ffa_send_direct_data *data,
531 				   struct optee_msg_arg *rpc_arg)
532 {
533 	struct optee *optee = tee_get_drvdata(ctx->teedev);
534 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
535 	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
536 	struct optee_call_waiter w;
537 	u32 cmd = data->data0;
538 	u32 w4 = data->data1;
539 	u32 w5 = data->data2;
540 	u32 w6 = data->data3;
541 	int rc;
542 
543 	/* Initialize waiter */
544 	optee_cq_wait_init(&optee->call_queue, &w);
545 	while (true) {
546 		rc = msg_ops->sync_send_receive(ffa_dev, data);
547 		if (rc)
548 			goto done;
549 
550 		switch ((int)data->data0) {
551 		case TEEC_SUCCESS:
552 			break;
553 		case TEEC_ERROR_BUSY:
554 			if (cmd == OPTEE_FFA_YIELDING_CALL_RESUME) {
555 				rc = -EIO;
556 				goto done;
557 			}
558 
559 			/*
560 			 * Out of threads in secure world, wait for a thread
561 			 * become available.
562 			 */
563 			optee_cq_wait_for_completion(&optee->call_queue, &w);
564 			data->data0 = cmd;
565 			data->data1 = w4;
566 			data->data2 = w5;
567 			data->data3 = w6;
568 			continue;
569 		default:
570 			rc = -EIO;
571 			goto done;
572 		}
573 
574 		if (data->data1 == OPTEE_FFA_YIELDING_CALL_RETURN_DONE)
575 			goto done;
576 
577 		/*
578 		 * OP-TEE has returned with a RPC request.
579 		 *
580 		 * Note that data->data4 (passed in register w7) is already
581 		 * filled in by ffa_mem_ops->sync_send_receive() returning
582 		 * above.
583 		 */
584 		cond_resched();
585 		optee_handle_ffa_rpc(ctx, optee, data->data1, rpc_arg);
586 		cmd = OPTEE_FFA_YIELDING_CALL_RESUME;
587 		data->data0 = cmd;
588 		data->data1 = 0;
589 		data->data2 = 0;
590 		data->data3 = 0;
591 	}
592 done:
593 	/*
594 	 * We're done with our thread in secure world, if there's any
595 	 * thread waiters wake up one.
596 	 */
597 	optee_cq_wait_final(&optee->call_queue, &w);
598 
599 	return rc;
600 }
601 
602 /**
603  * optee_ffa_do_call_with_arg() - Do a FF-A call to enter OP-TEE in secure world
604  * @ctx:	calling context
605  * @shm:	shared memory holding the message to pass to secure world
606  * @offs:	offset of the message in @shm
607  *
608  * Does a FF-A call to OP-TEE in secure world and handles eventual resulting
609  * Remote Procedure Calls (RPC) from OP-TEE.
610  *
611  * Returns return code from FF-A, 0 is OK
612  */
613 
614 static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
615 				      struct tee_shm *shm, u_int offs)
616 {
617 	struct ffa_send_direct_data data = {
618 		.data0 = OPTEE_FFA_YIELDING_CALL_WITH_ARG,
619 		.data1 = (u32)shm->sec_world_id,
620 		.data2 = (u32)(shm->sec_world_id >> 32),
621 		.data3 = offs,
622 	};
623 	struct optee_msg_arg *arg;
624 	unsigned int rpc_arg_offs;
625 	struct optee_msg_arg *rpc_arg;
626 
627 	/*
628 	 * The shared memory object has to start on a page when passed as
629 	 * an argument struct. This is also what the shm pool allocator
630 	 * returns, but check this before calling secure world to catch
631 	 * eventual errors early in case something changes.
632 	 */
633 	if (shm->offset)
634 		return -EINVAL;
635 
636 	arg = tee_shm_get_va(shm, offs);
637 	if (IS_ERR(arg))
638 		return PTR_ERR(arg);
639 
640 	rpc_arg_offs = OPTEE_MSG_GET_ARG_SIZE(arg->num_params);
641 	rpc_arg = tee_shm_get_va(shm, offs + rpc_arg_offs);
642 	if (IS_ERR(rpc_arg))
643 		return PTR_ERR(rpc_arg);
644 
645 	return optee_ffa_yielding_call(ctx, &data, rpc_arg);
646 }
647 
648 /*
649  * 6. Driver initialization
650  *
651  * During driver inititialization is the OP-TEE Secure Partition is probed
652  * to find out which features it supports so the driver can be initialized
653  * with a matching configuration.
654  */
655 
656 static bool optee_ffa_api_is_compatbile(struct ffa_device *ffa_dev,
657 					const struct ffa_ops *ops)
658 {
659 	const struct ffa_msg_ops *msg_ops = ops->msg_ops;
660 	struct ffa_send_direct_data data = { OPTEE_FFA_GET_API_VERSION };
661 	int rc;
662 
663 	msg_ops->mode_32bit_set(ffa_dev);
664 
665 	rc = msg_ops->sync_send_receive(ffa_dev, &data);
666 	if (rc) {
667 		pr_err("Unexpected error %d\n", rc);
668 		return false;
669 	}
670 	if (data.data0 != OPTEE_FFA_VERSION_MAJOR ||
671 	    data.data1 < OPTEE_FFA_VERSION_MINOR) {
672 		pr_err("Incompatible OP-TEE API version %lu.%lu",
673 		       data.data0, data.data1);
674 		return false;
675 	}
676 
677 	data = (struct ffa_send_direct_data){ OPTEE_FFA_GET_OS_VERSION };
678 	rc = msg_ops->sync_send_receive(ffa_dev, &data);
679 	if (rc) {
680 		pr_err("Unexpected error %d\n", rc);
681 		return false;
682 	}
683 	if (data.data2)
684 		pr_info("revision %lu.%lu (%08lx)",
685 			data.data0, data.data1, data.data2);
686 	else
687 		pr_info("revision %lu.%lu", data.data0, data.data1);
688 
689 	return true;
690 }
691 
692 static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
693 				    const struct ffa_ops *ops,
694 				    u32 *sec_caps,
695 				    unsigned int *rpc_param_count)
696 {
697 	struct ffa_send_direct_data data = { OPTEE_FFA_EXCHANGE_CAPABILITIES };
698 	int rc;
699 
700 	rc = ops->msg_ops->sync_send_receive(ffa_dev, &data);
701 	if (rc) {
702 		pr_err("Unexpected error %d", rc);
703 		return false;
704 	}
705 	if (data.data0) {
706 		pr_err("Unexpected exchange error %lu", data.data0);
707 		return false;
708 	}
709 
710 	*rpc_param_count = (u8)data.data1;
711 	*sec_caps = data.data2;
712 
713 	return true;
714 }
715 
716 static void optee_ffa_get_version(struct tee_device *teedev,
717 				  struct tee_ioctl_version_data *vers)
718 {
719 	struct tee_ioctl_version_data v = {
720 		.impl_id = TEE_IMPL_ID_OPTEE,
721 		.impl_caps = TEE_OPTEE_CAP_TZ,
722 		.gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
723 			    TEE_GEN_CAP_MEMREF_NULL,
724 	};
725 
726 	*vers = v;
727 }
728 
729 static int optee_ffa_open(struct tee_context *ctx)
730 {
731 	return optee_open(ctx, true);
732 }
733 
734 static const struct tee_driver_ops optee_ffa_clnt_ops = {
735 	.get_version = optee_ffa_get_version,
736 	.open = optee_ffa_open,
737 	.release = optee_release,
738 	.open_session = optee_open_session,
739 	.close_session = optee_close_session,
740 	.invoke_func = optee_invoke_func,
741 	.cancel_req = optee_cancel_req,
742 	.shm_register = optee_ffa_shm_register,
743 	.shm_unregister = optee_ffa_shm_unregister,
744 };
745 
746 static const struct tee_desc optee_ffa_clnt_desc = {
747 	.name = DRIVER_NAME "-ffa-clnt",
748 	.ops = &optee_ffa_clnt_ops,
749 	.owner = THIS_MODULE,
750 };
751 
752 static const struct tee_driver_ops optee_ffa_supp_ops = {
753 	.get_version = optee_ffa_get_version,
754 	.open = optee_ffa_open,
755 	.release = optee_release_supp,
756 	.supp_recv = optee_supp_recv,
757 	.supp_send = optee_supp_send,
758 	.shm_register = optee_ffa_shm_register, /* same as for clnt ops */
759 	.shm_unregister = optee_ffa_shm_unregister_supp,
760 };
761 
762 static const struct tee_desc optee_ffa_supp_desc = {
763 	.name = DRIVER_NAME "-ffa-supp",
764 	.ops = &optee_ffa_supp_ops,
765 	.owner = THIS_MODULE,
766 	.flags = TEE_DESC_PRIVILEGED,
767 };
768 
769 static const struct optee_ops optee_ffa_ops = {
770 	.do_call_with_arg = optee_ffa_do_call_with_arg,
771 	.to_msg_param = optee_ffa_to_msg_param,
772 	.from_msg_param = optee_ffa_from_msg_param,
773 };
774 
775 static void optee_ffa_remove(struct ffa_device *ffa_dev)
776 {
777 	struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
778 
779 	optee_remove_common(optee);
780 
781 	mutex_destroy(&optee->ffa.mutex);
782 	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
783 
784 	kfree(optee);
785 }
786 
787 static int optee_ffa_probe(struct ffa_device *ffa_dev)
788 {
789 	const struct ffa_ops *ffa_ops;
790 	unsigned int rpc_param_count;
791 	struct tee_shm_pool *pool;
792 	struct tee_device *teedev;
793 	struct tee_context *ctx;
794 	u32 arg_cache_flags = 0;
795 	struct optee *optee;
796 	u32 sec_caps;
797 	int rc;
798 
799 	ffa_ops = ffa_dev->ops;
800 
801 	if (!optee_ffa_api_is_compatbile(ffa_dev, ffa_ops))
802 		return -EINVAL;
803 
804 	if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
805 				     &rpc_param_count))
806 		return -EINVAL;
807 	if (sec_caps & OPTEE_FFA_SEC_CAP_ARG_OFFSET)
808 		arg_cache_flags |= OPTEE_SHM_ARG_SHARED;
809 
810 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
811 	if (!optee)
812 		return -ENOMEM;
813 
814 	pool = optee_ffa_shm_pool_alloc_pages();
815 	if (IS_ERR(pool)) {
816 		rc = PTR_ERR(pool);
817 		goto err_free_optee;
818 	}
819 	optee->pool = pool;
820 
821 	optee->ops = &optee_ffa_ops;
822 	optee->ffa.ffa_dev = ffa_dev;
823 	optee->rpc_param_count = rpc_param_count;
824 
825 	teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
826 				  optee);
827 	if (IS_ERR(teedev)) {
828 		rc = PTR_ERR(teedev);
829 		goto err_free_pool;
830 	}
831 	optee->teedev = teedev;
832 
833 	teedev = tee_device_alloc(&optee_ffa_supp_desc, NULL, optee->pool,
834 				  optee);
835 	if (IS_ERR(teedev)) {
836 		rc = PTR_ERR(teedev);
837 		goto err_unreg_teedev;
838 	}
839 	optee->supp_teedev = teedev;
840 
841 	rc = tee_device_register(optee->teedev);
842 	if (rc)
843 		goto err_unreg_supp_teedev;
844 
845 	rc = tee_device_register(optee->supp_teedev);
846 	if (rc)
847 		goto err_unreg_supp_teedev;
848 
849 	rc = rhashtable_init(&optee->ffa.global_ids, &shm_rhash_params);
850 	if (rc)
851 		goto err_unreg_supp_teedev;
852 	mutex_init(&optee->ffa.mutex);
853 	mutex_init(&optee->call_queue.mutex);
854 	INIT_LIST_HEAD(&optee->call_queue.waiters);
855 	optee_supp_init(&optee->supp);
856 	optee_shm_arg_cache_init(optee, arg_cache_flags);
857 	ffa_dev_set_drvdata(ffa_dev, optee);
858 	ctx = teedev_open(optee->teedev);
859 	if (IS_ERR(ctx)) {
860 		rc = PTR_ERR(ctx);
861 		goto err_rhashtable_free;
862 	}
863 	optee->ctx = ctx;
864 	rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
865 	if (rc)
866 		goto err_close_ctx;
867 
868 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
869 	if (rc)
870 		goto err_unregister_devices;
871 
872 	pr_info("initialized driver\n");
873 	return 0;
874 
875 err_unregister_devices:
876 	optee_unregister_devices();
877 	optee_notif_uninit(optee);
878 err_close_ctx:
879 	teedev_close_context(ctx);
880 err_rhashtable_free:
881 	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
882 	optee_supp_uninit(&optee->supp);
883 	mutex_destroy(&optee->call_queue.mutex);
884 	mutex_destroy(&optee->ffa.mutex);
885 err_unreg_supp_teedev:
886 	tee_device_unregister(optee->supp_teedev);
887 err_unreg_teedev:
888 	tee_device_unregister(optee->teedev);
889 err_free_pool:
890 	tee_shm_pool_free(pool);
891 err_free_optee:
892 	kfree(optee);
893 	return rc;
894 }
895 
896 static const struct ffa_device_id optee_ffa_device_id[] = {
897 	/* 486178e0-e7f8-11e3-bc5e0002a5d5c51b */
898 	{ UUID_INIT(0x486178e0, 0xe7f8, 0x11e3,
899 		    0xbc, 0x5e, 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b) },
900 	{}
901 };
902 
903 static struct ffa_driver optee_ffa_driver = {
904 	.name = "optee",
905 	.probe = optee_ffa_probe,
906 	.remove = optee_ffa_remove,
907 	.id_table = optee_ffa_device_id,
908 };
909 
910 int optee_ffa_abi_register(void)
911 {
912 	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
913 		return ffa_register(&optee_ffa_driver);
914 	else
915 		return -EOPNOTSUPP;
916 }
917 
918 void optee_ffa_abi_unregister(void)
919 {
920 	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
921 		ffa_unregister(&optee_ffa_driver);
922 }
923