xref: /openbmc/linux/drivers/tee/optee/ffa_abi.c (revision 62257638)
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 	const struct ffa_dev_ops *ffa_ops = optee->ffa.ffa_ops;
275 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
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 = ffa_ops->memory_share(ffa_dev, &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 		ffa_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 	const struct ffa_dev_ops *ffa_ops = optee->ffa.ffa_ops;
318 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
319 	u64 global_handle = shm->sec_world_id;
320 	struct ffa_send_direct_data data = {
321 		.data0 = OPTEE_FFA_UNREGISTER_SHM,
322 		.data1 = (u32)global_handle,
323 		.data2 = (u32)(global_handle >> 32)
324 	};
325 	int rc;
326 
327 	optee_shm_rem_ffa_handle(optee, global_handle);
328 	shm->sec_world_id = 0;
329 
330 	rc = ffa_ops->sync_send_receive(ffa_dev, &data);
331 	if (rc)
332 		pr_err("Unregister SHM id 0x%llx rc %d\n", global_handle, rc);
333 
334 	rc = ffa_ops->memory_reclaim(global_handle, 0);
335 	if (rc)
336 		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
337 
338 	return rc;
339 }
340 
341 static int optee_ffa_shm_unregister_supp(struct tee_context *ctx,
342 					 struct tee_shm *shm)
343 {
344 	struct optee *optee = tee_get_drvdata(ctx->teedev);
345 	const struct ffa_dev_ops *ffa_ops = optee->ffa.ffa_ops;
346 	u64 global_handle = shm->sec_world_id;
347 	int rc;
348 
349 	/*
350 	 * We're skipping the OPTEE_FFA_YIELDING_CALL_UNREGISTER_SHM call
351 	 * since this is OP-TEE freeing via RPC so it has already retired
352 	 * this ID.
353 	 */
354 
355 	optee_shm_rem_ffa_handle(optee, global_handle);
356 	rc = ffa_ops->memory_reclaim(global_handle, 0);
357 	if (rc)
358 		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
359 
360 	shm->sec_world_id = 0;
361 
362 	return rc;
363 }
364 
365 /*
366  * 4. Dynamic shared memory pool based on alloc_pages()
367  *
368  * Implements an OP-TEE specific shared memory pool.
369  * The main function is optee_ffa_shm_pool_alloc_pages().
370  */
371 
372 static int pool_ffa_op_alloc(struct tee_shm_pool *pool,
373 			     struct tee_shm *shm, size_t size, size_t align)
374 {
375 	return optee_pool_op_alloc_helper(pool, shm, size, align,
376 					  optee_ffa_shm_register);
377 }
378 
379 static void pool_ffa_op_free(struct tee_shm_pool *pool,
380 			     struct tee_shm *shm)
381 {
382 	optee_pool_op_free_helper(pool, shm, optee_ffa_shm_unregister);
383 }
384 
385 static void pool_ffa_op_destroy_pool(struct tee_shm_pool *pool)
386 {
387 	kfree(pool);
388 }
389 
390 static const struct tee_shm_pool_ops pool_ffa_ops = {
391 	.alloc = pool_ffa_op_alloc,
392 	.free = pool_ffa_op_free,
393 	.destroy_pool = pool_ffa_op_destroy_pool,
394 };
395 
396 /**
397  * optee_ffa_shm_pool_alloc_pages() - create page-based allocator pool
398  *
399  * This pool is used with OP-TEE over FF-A. In this case command buffers
400  * and such are allocated from kernel's own memory.
401  */
402 static struct tee_shm_pool *optee_ffa_shm_pool_alloc_pages(void)
403 {
404 	struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
405 
406 	if (!pool)
407 		return ERR_PTR(-ENOMEM);
408 
409 	pool->ops = &pool_ffa_ops;
410 
411 	return pool;
412 }
413 
414 /*
415  * 5. Do a normal scheduled call into secure world
416  *
417  * The function optee_ffa_do_call_with_arg() performs a normal scheduled
418  * call into secure world. During this call may normal world request help
419  * from normal world using RPCs, Remote Procedure Calls. This includes
420  * delivery of non-secure interrupts to for instance allow rescheduling of
421  * the current task.
422  */
423 
424 static void handle_ffa_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
425 					      struct optee *optee,
426 					      struct optee_msg_arg *arg)
427 {
428 	struct tee_shm *shm;
429 
430 	if (arg->num_params != 1 ||
431 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
432 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
433 		return;
434 	}
435 
436 	switch (arg->params[0].u.value.a) {
437 	case OPTEE_RPC_SHM_TYPE_APPL:
438 		shm = optee_rpc_cmd_alloc_suppl(ctx, arg->params[0].u.value.b);
439 		break;
440 	case OPTEE_RPC_SHM_TYPE_KERNEL:
441 		shm = tee_shm_alloc_priv_buf(optee->ctx,
442 					     arg->params[0].u.value.b);
443 		break;
444 	default:
445 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
446 		return;
447 	}
448 
449 	if (IS_ERR(shm)) {
450 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
451 		return;
452 	}
453 
454 	arg->params[0] = (struct optee_msg_param){
455 		.attr = OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT,
456 		.u.fmem.size = tee_shm_get_size(shm),
457 		.u.fmem.global_id = shm->sec_world_id,
458 		.u.fmem.internal_offs = shm->offset,
459 	};
460 
461 	arg->ret = TEEC_SUCCESS;
462 }
463 
464 static void handle_ffa_rpc_func_cmd_shm_free(struct tee_context *ctx,
465 					     struct optee *optee,
466 					     struct optee_msg_arg *arg)
467 {
468 	struct tee_shm *shm;
469 
470 	if (arg->num_params != 1 ||
471 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
472 		goto err_bad_param;
473 
474 	shm = optee_shm_from_ffa_handle(optee, arg->params[0].u.value.b);
475 	if (!shm)
476 		goto err_bad_param;
477 	switch (arg->params[0].u.value.a) {
478 	case OPTEE_RPC_SHM_TYPE_APPL:
479 		optee_rpc_cmd_free_suppl(ctx, shm);
480 		break;
481 	case OPTEE_RPC_SHM_TYPE_KERNEL:
482 		tee_shm_free(shm);
483 		break;
484 	default:
485 		goto err_bad_param;
486 	}
487 	arg->ret = TEEC_SUCCESS;
488 	return;
489 
490 err_bad_param:
491 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
492 }
493 
494 static void handle_ffa_rpc_func_cmd(struct tee_context *ctx,
495 				    struct optee *optee,
496 				    struct optee_msg_arg *arg)
497 {
498 	arg->ret_origin = TEEC_ORIGIN_COMMS;
499 	switch (arg->cmd) {
500 	case OPTEE_RPC_CMD_SHM_ALLOC:
501 		handle_ffa_rpc_func_cmd_shm_alloc(ctx, optee, arg);
502 		break;
503 	case OPTEE_RPC_CMD_SHM_FREE:
504 		handle_ffa_rpc_func_cmd_shm_free(ctx, optee, arg);
505 		break;
506 	default:
507 		optee_rpc_cmd(ctx, optee, arg);
508 	}
509 }
510 
511 static void optee_handle_ffa_rpc(struct tee_context *ctx, struct optee *optee,
512 				 u32 cmd, struct optee_msg_arg *arg)
513 {
514 	switch (cmd) {
515 	case OPTEE_FFA_YIELDING_CALL_RETURN_RPC_CMD:
516 		handle_ffa_rpc_func_cmd(ctx, optee, arg);
517 		break;
518 	case OPTEE_FFA_YIELDING_CALL_RETURN_INTERRUPT:
519 		/* Interrupt delivered by now */
520 		break;
521 	default:
522 		pr_warn("Unknown RPC func 0x%x\n", cmd);
523 		break;
524 	}
525 }
526 
527 static int optee_ffa_yielding_call(struct tee_context *ctx,
528 				   struct ffa_send_direct_data *data,
529 				   struct optee_msg_arg *rpc_arg)
530 {
531 	struct optee *optee = tee_get_drvdata(ctx->teedev);
532 	const struct ffa_dev_ops *ffa_ops = optee->ffa.ffa_ops;
533 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
534 	struct optee_call_waiter w;
535 	u32 cmd = data->data0;
536 	u32 w4 = data->data1;
537 	u32 w5 = data->data2;
538 	u32 w6 = data->data3;
539 	int rc;
540 
541 	/* Initialize waiter */
542 	optee_cq_wait_init(&optee->call_queue, &w);
543 	while (true) {
544 		rc = ffa_ops->sync_send_receive(ffa_dev, data);
545 		if (rc)
546 			goto done;
547 
548 		switch ((int)data->data0) {
549 		case TEEC_SUCCESS:
550 			break;
551 		case TEEC_ERROR_BUSY:
552 			if (cmd == OPTEE_FFA_YIELDING_CALL_RESUME) {
553 				rc = -EIO;
554 				goto done;
555 			}
556 
557 			/*
558 			 * Out of threads in secure world, wait for a thread
559 			 * become available.
560 			 */
561 			optee_cq_wait_for_completion(&optee->call_queue, &w);
562 			data->data0 = cmd;
563 			data->data1 = w4;
564 			data->data2 = w5;
565 			data->data3 = w6;
566 			continue;
567 		default:
568 			rc = -EIO;
569 			goto done;
570 		}
571 
572 		if (data->data1 == OPTEE_FFA_YIELDING_CALL_RETURN_DONE)
573 			goto done;
574 
575 		/*
576 		 * OP-TEE has returned with a RPC request.
577 		 *
578 		 * Note that data->data4 (passed in register w7) is already
579 		 * filled in by ffa_ops->sync_send_receive() returning
580 		 * above.
581 		 */
582 		cond_resched();
583 		optee_handle_ffa_rpc(ctx, optee, data->data1, rpc_arg);
584 		cmd = OPTEE_FFA_YIELDING_CALL_RESUME;
585 		data->data0 = cmd;
586 		data->data1 = 0;
587 		data->data2 = 0;
588 		data->data3 = 0;
589 	}
590 done:
591 	/*
592 	 * We're done with our thread in secure world, if there's any
593 	 * thread waiters wake up one.
594 	 */
595 	optee_cq_wait_final(&optee->call_queue, &w);
596 
597 	return rc;
598 }
599 
600 /**
601  * optee_ffa_do_call_with_arg() - Do a FF-A call to enter OP-TEE in secure world
602  * @ctx:	calling context
603  * @shm:	shared memory holding the message to pass to secure world
604  * @offs:	offset of the message in @shm
605  *
606  * Does a FF-A call to OP-TEE in secure world and handles eventual resulting
607  * Remote Procedure Calls (RPC) from OP-TEE.
608  *
609  * Returns return code from FF-A, 0 is OK
610  */
611 
612 static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
613 				      struct tee_shm *shm, u_int offs)
614 {
615 	struct ffa_send_direct_data data = {
616 		.data0 = OPTEE_FFA_YIELDING_CALL_WITH_ARG,
617 		.data1 = (u32)shm->sec_world_id,
618 		.data2 = (u32)(shm->sec_world_id >> 32),
619 		.data3 = offs,
620 	};
621 	struct optee_msg_arg *arg;
622 	unsigned int rpc_arg_offs;
623 	struct optee_msg_arg *rpc_arg;
624 
625 	/*
626 	 * The shared memory object has to start on a page when passed as
627 	 * an argument struct. This is also what the shm pool allocator
628 	 * returns, but check this before calling secure world to catch
629 	 * eventual errors early in case something changes.
630 	 */
631 	if (shm->offset)
632 		return -EINVAL;
633 
634 	arg = tee_shm_get_va(shm, offs);
635 	if (IS_ERR(arg))
636 		return PTR_ERR(arg);
637 
638 	rpc_arg_offs = OPTEE_MSG_GET_ARG_SIZE(arg->num_params);
639 	rpc_arg = tee_shm_get_va(shm, offs + rpc_arg_offs);
640 	if (IS_ERR(rpc_arg))
641 		return PTR_ERR(rpc_arg);
642 
643 	return optee_ffa_yielding_call(ctx, &data, rpc_arg);
644 }
645 
646 /*
647  * 6. Driver initialization
648  *
649  * During driver inititialization is the OP-TEE Secure Partition is probed
650  * to find out which features it supports so the driver can be initialized
651  * with a matching configuration.
652  */
653 
654 static bool optee_ffa_api_is_compatbile(struct ffa_device *ffa_dev,
655 					const struct ffa_dev_ops *ops)
656 {
657 	struct ffa_send_direct_data data = { OPTEE_FFA_GET_API_VERSION };
658 	int rc;
659 
660 	ops->mode_32bit_set(ffa_dev);
661 
662 	rc = ops->sync_send_receive(ffa_dev, &data);
663 	if (rc) {
664 		pr_err("Unexpected error %d\n", rc);
665 		return false;
666 	}
667 	if (data.data0 != OPTEE_FFA_VERSION_MAJOR ||
668 	    data.data1 < OPTEE_FFA_VERSION_MINOR) {
669 		pr_err("Incompatible OP-TEE API version %lu.%lu",
670 		       data.data0, data.data1);
671 		return false;
672 	}
673 
674 	data = (struct ffa_send_direct_data){ OPTEE_FFA_GET_OS_VERSION };
675 	rc = ops->sync_send_receive(ffa_dev, &data);
676 	if (rc) {
677 		pr_err("Unexpected error %d\n", rc);
678 		return false;
679 	}
680 	if (data.data2)
681 		pr_info("revision %lu.%lu (%08lx)",
682 			data.data0, data.data1, data.data2);
683 	else
684 		pr_info("revision %lu.%lu", data.data0, data.data1);
685 
686 	return true;
687 }
688 
689 static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
690 				    const struct ffa_dev_ops *ops,
691 				    u32 *sec_caps,
692 				    unsigned int *rpc_param_count)
693 {
694 	struct ffa_send_direct_data data = { OPTEE_FFA_EXCHANGE_CAPABILITIES };
695 	int rc;
696 
697 	rc = ops->sync_send_receive(ffa_dev, &data);
698 	if (rc) {
699 		pr_err("Unexpected error %d", rc);
700 		return false;
701 	}
702 	if (data.data0) {
703 		pr_err("Unexpected exchange error %lu", data.data0);
704 		return false;
705 	}
706 
707 	*rpc_param_count = (u8)data.data1;
708 	*sec_caps = data.data2;
709 
710 	return true;
711 }
712 
713 static void optee_ffa_get_version(struct tee_device *teedev,
714 				  struct tee_ioctl_version_data *vers)
715 {
716 	struct tee_ioctl_version_data v = {
717 		.impl_id = TEE_IMPL_ID_OPTEE,
718 		.impl_caps = TEE_OPTEE_CAP_TZ,
719 		.gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
720 			    TEE_GEN_CAP_MEMREF_NULL,
721 	};
722 
723 	*vers = v;
724 }
725 
726 static int optee_ffa_open(struct tee_context *ctx)
727 {
728 	return optee_open(ctx, true);
729 }
730 
731 static const struct tee_driver_ops optee_ffa_clnt_ops = {
732 	.get_version = optee_ffa_get_version,
733 	.open = optee_ffa_open,
734 	.release = optee_release,
735 	.open_session = optee_open_session,
736 	.close_session = optee_close_session,
737 	.invoke_func = optee_invoke_func,
738 	.cancel_req = optee_cancel_req,
739 	.shm_register = optee_ffa_shm_register,
740 	.shm_unregister = optee_ffa_shm_unregister,
741 };
742 
743 static const struct tee_desc optee_ffa_clnt_desc = {
744 	.name = DRIVER_NAME "-ffa-clnt",
745 	.ops = &optee_ffa_clnt_ops,
746 	.owner = THIS_MODULE,
747 };
748 
749 static const struct tee_driver_ops optee_ffa_supp_ops = {
750 	.get_version = optee_ffa_get_version,
751 	.open = optee_ffa_open,
752 	.release = optee_release_supp,
753 	.supp_recv = optee_supp_recv,
754 	.supp_send = optee_supp_send,
755 	.shm_register = optee_ffa_shm_register, /* same as for clnt ops */
756 	.shm_unregister = optee_ffa_shm_unregister_supp,
757 };
758 
759 static const struct tee_desc optee_ffa_supp_desc = {
760 	.name = DRIVER_NAME "-ffa-supp",
761 	.ops = &optee_ffa_supp_ops,
762 	.owner = THIS_MODULE,
763 	.flags = TEE_DESC_PRIVILEGED,
764 };
765 
766 static const struct optee_ops optee_ffa_ops = {
767 	.do_call_with_arg = optee_ffa_do_call_with_arg,
768 	.to_msg_param = optee_ffa_to_msg_param,
769 	.from_msg_param = optee_ffa_from_msg_param,
770 };
771 
772 static void optee_ffa_remove(struct ffa_device *ffa_dev)
773 {
774 	struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
775 
776 	optee_remove_common(optee);
777 
778 	mutex_destroy(&optee->ffa.mutex);
779 	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
780 
781 	kfree(optee);
782 }
783 
784 static int optee_ffa_probe(struct ffa_device *ffa_dev)
785 {
786 	const struct ffa_dev_ops *ffa_ops;
787 	unsigned int rpc_param_count;
788 	struct tee_shm_pool *pool;
789 	struct tee_device *teedev;
790 	struct tee_context *ctx;
791 	u32 arg_cache_flags = 0;
792 	struct optee *optee;
793 	u32 sec_caps;
794 	int rc;
795 
796 	ffa_ops = ffa_dev_ops_get(ffa_dev);
797 	if (!ffa_ops) {
798 		pr_warn("failed \"method\" init: ffa\n");
799 		return -ENOENT;
800 	}
801 
802 	if (!optee_ffa_api_is_compatbile(ffa_dev, ffa_ops))
803 		return -EINVAL;
804 
805 	if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
806 				     &rpc_param_count))
807 		return -EINVAL;
808 	if (sec_caps & OPTEE_FFA_SEC_CAP_ARG_OFFSET)
809 		arg_cache_flags |= OPTEE_SHM_ARG_SHARED;
810 
811 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
812 	if (!optee)
813 		return -ENOMEM;
814 
815 	pool = optee_ffa_shm_pool_alloc_pages();
816 	if (IS_ERR(pool)) {
817 		rc = PTR_ERR(pool);
818 		goto err_free_optee;
819 	}
820 	optee->pool = pool;
821 
822 	optee->ops = &optee_ffa_ops;
823 	optee->ffa.ffa_dev = ffa_dev;
824 	optee->ffa.ffa_ops = ffa_ops;
825 	optee->rpc_param_count = rpc_param_count;
826 
827 	teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
828 				  optee);
829 	if (IS_ERR(teedev)) {
830 		rc = PTR_ERR(teedev);
831 		goto err_free_pool;
832 	}
833 	optee->teedev = teedev;
834 
835 	teedev = tee_device_alloc(&optee_ffa_supp_desc, NULL, optee->pool,
836 				  optee);
837 	if (IS_ERR(teedev)) {
838 		rc = PTR_ERR(teedev);
839 		goto err_unreg_teedev;
840 	}
841 	optee->supp_teedev = teedev;
842 
843 	rc = tee_device_register(optee->teedev);
844 	if (rc)
845 		goto err_unreg_supp_teedev;
846 
847 	rc = tee_device_register(optee->supp_teedev);
848 	if (rc)
849 		goto err_unreg_supp_teedev;
850 
851 	rc = rhashtable_init(&optee->ffa.global_ids, &shm_rhash_params);
852 	if (rc)
853 		goto err_unreg_supp_teedev;
854 	mutex_init(&optee->ffa.mutex);
855 	mutex_init(&optee->call_queue.mutex);
856 	INIT_LIST_HEAD(&optee->call_queue.waiters);
857 	optee_supp_init(&optee->supp);
858 	optee_shm_arg_cache_init(optee, arg_cache_flags);
859 	ffa_dev_set_drvdata(ffa_dev, optee);
860 	ctx = teedev_open(optee->teedev);
861 	if (IS_ERR(ctx)) {
862 		rc = PTR_ERR(ctx);
863 		goto err_rhashtable_free;
864 	}
865 	optee->ctx = ctx;
866 	rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
867 	if (rc)
868 		goto err_close_ctx;
869 
870 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
871 	if (rc)
872 		goto err_unregister_devices;
873 
874 	pr_info("initialized driver\n");
875 	return 0;
876 
877 err_unregister_devices:
878 	optee_unregister_devices();
879 	optee_notif_uninit(optee);
880 err_close_ctx:
881 	teedev_close_context(ctx);
882 err_rhashtable_free:
883 	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
884 	optee_supp_uninit(&optee->supp);
885 	mutex_destroy(&optee->call_queue.mutex);
886 	mutex_destroy(&optee->ffa.mutex);
887 err_unreg_supp_teedev:
888 	tee_device_unregister(optee->supp_teedev);
889 err_unreg_teedev:
890 	tee_device_unregister(optee->teedev);
891 err_free_pool:
892 	tee_shm_pool_free(pool);
893 err_free_optee:
894 	kfree(optee);
895 	return rc;
896 }
897 
898 static const struct ffa_device_id optee_ffa_device_id[] = {
899 	/* 486178e0-e7f8-11e3-bc5e0002a5d5c51b */
900 	{ UUID_INIT(0x486178e0, 0xe7f8, 0x11e3,
901 		    0xbc, 0x5e, 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b) },
902 	{}
903 };
904 
905 static struct ffa_driver optee_ffa_driver = {
906 	.name = "optee",
907 	.probe = optee_ffa_probe,
908 	.remove = optee_ffa_remove,
909 	.id_table = optee_ffa_device_id,
910 };
911 
912 int optee_ffa_abi_register(void)
913 {
914 	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
915 		return ffa_register(&optee_ffa_driver);
916 	else
917 		return -EOPNOTSUPP;
918 }
919 
920 void optee_ffa_abi_unregister(void)
921 {
922 	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
923 		ffa_unregister(&optee_ffa_driver);
924 }
925