xref: /linux/drivers/tee/optee/ffa_abi.c (revision f858cc9eed5b05cbe38d7ffd2787c21e3718eb7d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2021, 2023 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/rpmb.h>
11 #include <linux/scatterlist.h>
12 #include <linux/sched.h>
13 #include <linux/slab.h>
14 #include <linux/string.h>
15 #include <linux/tee_core.h>
16 #include <linux/types.h>
17 #include "optee_private.h"
18 #include "optee_ffa.h"
19 #include "optee_rpc_cmd.h"
20 
21 /*
22  * This file implement the FF-A ABI used when communicating with secure world
23  * OP-TEE OS via FF-A.
24  * This file is divided into the following sections:
25  * 1. Maintain a hash table for lookup of a global FF-A memory handle
26  * 2. Convert between struct tee_param and struct optee_msg_param
27  * 3. Low level support functions to register shared memory in secure world
28  * 4. Dynamic shared memory pool based on alloc_pages()
29  * 5. Do a normal scheduled call into secure world
30  * 6. Driver initialization.
31  */
32 
33 /*
34  * 1. Maintain a hash table for lookup of a global FF-A memory handle
35  *
36  * FF-A assigns a global memory handle for each piece shared memory.
37  * This handle is then used when communicating with secure world.
38  *
39  * Main functions are optee_shm_add_ffa_handle() and optee_shm_rem_ffa_handle()
40  */
41 struct shm_rhash {
42 	struct tee_shm *shm;
43 	u64 global_id;
44 	struct rhash_head linkage;
45 };
46 
47 static void rh_free_fn(void *ptr, void *arg)
48 {
49 	kfree(ptr);
50 }
51 
52 static const struct rhashtable_params shm_rhash_params = {
53 	.head_offset = offsetof(struct shm_rhash, linkage),
54 	.key_len     = sizeof(u64),
55 	.key_offset  = offsetof(struct shm_rhash, global_id),
56 	.automatic_shrinking = true,
57 };
58 
59 static struct tee_shm *optee_shm_from_ffa_handle(struct optee *optee,
60 						 u64 global_id)
61 {
62 	struct tee_shm *shm = NULL;
63 	struct shm_rhash *r;
64 
65 	mutex_lock(&optee->ffa.mutex);
66 	r = rhashtable_lookup_fast(&optee->ffa.global_ids, &global_id,
67 				   shm_rhash_params);
68 	if (r)
69 		shm = r->shm;
70 	mutex_unlock(&optee->ffa.mutex);
71 
72 	return shm;
73 }
74 
75 static int optee_shm_add_ffa_handle(struct optee *optee, struct tee_shm *shm,
76 				    u64 global_id)
77 {
78 	struct shm_rhash *r;
79 	int rc;
80 
81 	r = kmalloc(sizeof(*r), GFP_KERNEL);
82 	if (!r)
83 		return -ENOMEM;
84 	r->shm = shm;
85 	r->global_id = global_id;
86 
87 	mutex_lock(&optee->ffa.mutex);
88 	rc = rhashtable_lookup_insert_fast(&optee->ffa.global_ids, &r->linkage,
89 					   shm_rhash_params);
90 	mutex_unlock(&optee->ffa.mutex);
91 
92 	if (rc)
93 		kfree(r);
94 
95 	return rc;
96 }
97 
98 static int optee_shm_rem_ffa_handle(struct optee *optee, u64 global_id)
99 {
100 	struct shm_rhash *r;
101 	int rc = -ENOENT;
102 
103 	mutex_lock(&optee->ffa.mutex);
104 	r = rhashtable_lookup_fast(&optee->ffa.global_ids, &global_id,
105 				   shm_rhash_params);
106 	if (r)
107 		rc = rhashtable_remove_fast(&optee->ffa.global_ids,
108 					    &r->linkage, shm_rhash_params);
109 	mutex_unlock(&optee->ffa.mutex);
110 
111 	if (!rc)
112 		kfree(r);
113 
114 	return rc;
115 }
116 
117 /*
118  * 2. Convert between struct tee_param and struct optee_msg_param
119  *
120  * optee_ffa_from_msg_param() and optee_ffa_to_msg_param() are the main
121  * functions.
122  */
123 
124 static void from_msg_param_ffa_mem(struct optee *optee, struct tee_param *p,
125 				   u32 attr, const struct optee_msg_param *mp)
126 {
127 	struct tee_shm *shm = NULL;
128 	u64 offs_high = 0;
129 	u64 offs_low = 0;
130 
131 	p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
132 		  attr - OPTEE_MSG_ATTR_TYPE_FMEM_INPUT;
133 	p->u.memref.size = mp->u.fmem.size;
134 
135 	if (mp->u.fmem.global_id != OPTEE_MSG_FMEM_INVALID_GLOBAL_ID)
136 		shm = optee_shm_from_ffa_handle(optee, mp->u.fmem.global_id);
137 	p->u.memref.shm = shm;
138 
139 	if (shm) {
140 		offs_low = mp->u.fmem.offs_low;
141 		offs_high = mp->u.fmem.offs_high;
142 	}
143 	p->u.memref.shm_offs = offs_low | offs_high << 32;
144 }
145 
146 /**
147  * optee_ffa_from_msg_param() - convert from OPTEE_MSG parameters to
148  *				struct tee_param
149  * @optee:	main service struct
150  * @params:	subsystem internal parameter representation
151  * @num_params:	number of elements in the parameter arrays
152  * @msg_params:	OPTEE_MSG parameters
153  *
154  * Returns 0 on success or <0 on failure
155  */
156 static int optee_ffa_from_msg_param(struct optee *optee,
157 				    struct tee_param *params, size_t num_params,
158 				    const struct optee_msg_param *msg_params)
159 {
160 	size_t n;
161 
162 	for (n = 0; n < num_params; n++) {
163 		struct tee_param *p = params + n;
164 		const struct optee_msg_param *mp = msg_params + n;
165 		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
166 
167 		switch (attr) {
168 		case OPTEE_MSG_ATTR_TYPE_NONE:
169 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
170 			memset(&p->u, 0, sizeof(p->u));
171 			break;
172 		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
173 		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
174 		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
175 			optee_from_msg_param_value(p, attr, mp);
176 			break;
177 		case OPTEE_MSG_ATTR_TYPE_FMEM_INPUT:
178 		case OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT:
179 		case OPTEE_MSG_ATTR_TYPE_FMEM_INOUT:
180 			from_msg_param_ffa_mem(optee, p, attr, mp);
181 			break;
182 		default:
183 			return -EINVAL;
184 		}
185 	}
186 
187 	return 0;
188 }
189 
190 static int to_msg_param_ffa_mem(struct optee_msg_param *mp,
191 				const struct tee_param *p)
192 {
193 	struct tee_shm *shm = p->u.memref.shm;
194 
195 	mp->attr = OPTEE_MSG_ATTR_TYPE_FMEM_INPUT + p->attr -
196 		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
197 
198 	if (shm) {
199 		u64 shm_offs = p->u.memref.shm_offs;
200 
201 		mp->u.fmem.internal_offs = shm->offset;
202 
203 		mp->u.fmem.offs_low = shm_offs;
204 		mp->u.fmem.offs_high = shm_offs >> 32;
205 		/* Check that the entire offset could be stored. */
206 		if (mp->u.fmem.offs_high != shm_offs >> 32)
207 			return -EINVAL;
208 
209 		mp->u.fmem.global_id = shm->sec_world_id;
210 	} else {
211 		memset(&mp->u, 0, sizeof(mp->u));
212 		mp->u.fmem.global_id = OPTEE_MSG_FMEM_INVALID_GLOBAL_ID;
213 	}
214 	mp->u.fmem.size = p->u.memref.size;
215 
216 	return 0;
217 }
218 
219 /**
220  * optee_ffa_to_msg_param() - convert from struct tee_params to OPTEE_MSG
221  *			      parameters
222  * @optee:	main service struct
223  * @msg_params:	OPTEE_MSG parameters
224  * @num_params:	number of elements in the parameter arrays
225  * @params:	subsystem itnernal parameter representation
226  * Returns 0 on success or <0 on failure
227  */
228 static int optee_ffa_to_msg_param(struct optee *optee,
229 				  struct optee_msg_param *msg_params,
230 				  size_t num_params,
231 				  const struct tee_param *params)
232 {
233 	size_t n;
234 
235 	for (n = 0; n < num_params; n++) {
236 		const struct tee_param *p = params + n;
237 		struct optee_msg_param *mp = msg_params + n;
238 
239 		switch (p->attr) {
240 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
241 			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
242 			memset(&mp->u, 0, sizeof(mp->u));
243 			break;
244 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
245 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
246 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
247 			optee_to_msg_param_value(mp, p);
248 			break;
249 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
250 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
251 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
252 			if (to_msg_param_ffa_mem(mp, p))
253 				return -EINVAL;
254 			break;
255 		default:
256 			return -EINVAL;
257 		}
258 	}
259 
260 	return 0;
261 }
262 
263 /*
264  * 3. Low level support functions to register shared memory in secure world
265  *
266  * Functions to register and unregister shared memory both for normal
267  * clients and for tee-supplicant.
268  */
269 
270 static int optee_ffa_shm_register(struct tee_context *ctx, struct tee_shm *shm,
271 				  struct page **pages, size_t num_pages,
272 				  unsigned long start)
273 {
274 	struct optee *optee = tee_get_drvdata(ctx->teedev);
275 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
276 	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
277 	struct ffa_mem_region_attributes mem_attr = {
278 		.receiver = ffa_dev->vm_id,
279 		.attrs = FFA_MEM_RW,
280 	};
281 	struct ffa_mem_ops_args args = {
282 		.use_txbuf = true,
283 		.attrs = &mem_attr,
284 		.nattrs = 1,
285 	};
286 	struct sg_table sgt;
287 	int rc;
288 
289 	rc = optee_check_mem_type(start, num_pages);
290 	if (rc)
291 		return rc;
292 
293 	rc = sg_alloc_table_from_pages(&sgt, pages, num_pages, 0,
294 				       num_pages * PAGE_SIZE, GFP_KERNEL);
295 	if (rc)
296 		return rc;
297 	args.sg = sgt.sgl;
298 	rc = mem_ops->memory_share(&args);
299 	sg_free_table(&sgt);
300 	if (rc)
301 		return rc;
302 
303 	rc = optee_shm_add_ffa_handle(optee, shm, args.g_handle);
304 	if (rc) {
305 		mem_ops->memory_reclaim(args.g_handle, 0);
306 		return rc;
307 	}
308 
309 	shm->sec_world_id = args.g_handle;
310 
311 	return 0;
312 }
313 
314 static int optee_ffa_shm_unregister(struct tee_context *ctx,
315 				    struct tee_shm *shm)
316 {
317 	struct optee *optee = tee_get_drvdata(ctx->teedev);
318 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
319 	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
320 	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
321 	u64 global_handle = shm->sec_world_id;
322 	struct ffa_send_direct_data data = {
323 		.data0 = OPTEE_FFA_UNREGISTER_SHM,
324 		.data1 = (u32)global_handle,
325 		.data2 = (u32)(global_handle >> 32)
326 	};
327 	int rc;
328 
329 	optee_shm_rem_ffa_handle(optee, global_handle);
330 	shm->sec_world_id = 0;
331 
332 	rc = msg_ops->sync_send_receive(ffa_dev, &data);
333 	if (rc)
334 		pr_err("Unregister SHM id 0x%llx rc %d\n", global_handle, rc);
335 
336 	rc = mem_ops->memory_reclaim(global_handle, 0);
337 	if (rc)
338 		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
339 
340 	return rc;
341 }
342 
343 static int optee_ffa_shm_unregister_supp(struct tee_context *ctx,
344 					 struct tee_shm *shm)
345 {
346 	struct optee *optee = tee_get_drvdata(ctx->teedev);
347 	const struct ffa_mem_ops *mem_ops;
348 	u64 global_handle = shm->sec_world_id;
349 	int rc;
350 
351 	/*
352 	 * We're skipping the OPTEE_FFA_YIELDING_CALL_UNREGISTER_SHM call
353 	 * since this is OP-TEE freeing via RPC so it has already retired
354 	 * this ID.
355 	 */
356 
357 	optee_shm_rem_ffa_handle(optee, global_handle);
358 	mem_ops = optee->ffa.ffa_dev->ops->mem_ops;
359 	rc = mem_ops->memory_reclaim(global_handle, 0);
360 	if (rc)
361 		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
362 
363 	shm->sec_world_id = 0;
364 
365 	return rc;
366 }
367 
368 /*
369  * 4. Dynamic shared memory pool based on alloc_pages()
370  *
371  * Implements an OP-TEE specific shared memory pool.
372  * The main function is optee_ffa_shm_pool_alloc_pages().
373  */
374 
375 static int pool_ffa_op_alloc(struct tee_shm_pool *pool,
376 			     struct tee_shm *shm, size_t size, size_t align)
377 {
378 	return tee_dyn_shm_alloc_helper(shm, size, align,
379 					optee_ffa_shm_register);
380 }
381 
382 static void pool_ffa_op_free(struct tee_shm_pool *pool,
383 			     struct tee_shm *shm)
384 {
385 	tee_dyn_shm_free_helper(shm, optee_ffa_shm_unregister);
386 }
387 
388 static void pool_ffa_op_destroy_pool(struct tee_shm_pool *pool)
389 {
390 	kfree(pool);
391 }
392 
393 static const struct tee_shm_pool_ops pool_ffa_ops = {
394 	.alloc = pool_ffa_op_alloc,
395 	.free = pool_ffa_op_free,
396 	.destroy_pool = pool_ffa_op_destroy_pool,
397 };
398 
399 /**
400  * optee_ffa_shm_pool_alloc_pages() - create page-based allocator pool
401  *
402  * This pool is used with OP-TEE over FF-A. In this case command buffers
403  * and such are allocated from kernel's own memory.
404  */
405 static struct tee_shm_pool *optee_ffa_shm_pool_alloc_pages(void)
406 {
407 	struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
408 
409 	if (!pool)
410 		return ERR_PTR(-ENOMEM);
411 
412 	pool->ops = &pool_ffa_ops;
413 
414 	return pool;
415 }
416 
417 /*
418  * 5. Do a normal scheduled call into secure world
419  *
420  * The function optee_ffa_do_call_with_arg() performs a normal scheduled
421  * call into secure world. During this call may normal world request help
422  * from normal world using RPCs, Remote Procedure Calls. This includes
423  * delivery of non-secure interrupts to for instance allow rescheduling of
424  * the current task.
425  */
426 
427 static void handle_ffa_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
428 					      struct optee *optee,
429 					      struct optee_msg_arg *arg)
430 {
431 	struct tee_shm *shm;
432 
433 	if (arg->num_params != 1 ||
434 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
435 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
436 		return;
437 	}
438 
439 	switch (arg->params[0].u.value.a) {
440 	case OPTEE_RPC_SHM_TYPE_APPL:
441 		shm = optee_rpc_cmd_alloc_suppl(ctx, arg->params[0].u.value.b);
442 		break;
443 	case OPTEE_RPC_SHM_TYPE_KERNEL:
444 		shm = tee_shm_alloc_priv_buf(optee->ctx,
445 					     arg->params[0].u.value.b);
446 		break;
447 	default:
448 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
449 		return;
450 	}
451 
452 	if (IS_ERR(shm)) {
453 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
454 		return;
455 	}
456 
457 	arg->params[0] = (struct optee_msg_param){
458 		.attr = OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT,
459 		.u.fmem.size = tee_shm_get_size(shm),
460 		.u.fmem.global_id = shm->sec_world_id,
461 		.u.fmem.internal_offs = shm->offset,
462 	};
463 
464 	arg->ret = TEEC_SUCCESS;
465 }
466 
467 static void handle_ffa_rpc_func_cmd_shm_free(struct tee_context *ctx,
468 					     struct optee *optee,
469 					     struct optee_msg_arg *arg)
470 {
471 	struct tee_shm *shm;
472 
473 	if (arg->num_params != 1 ||
474 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
475 		goto err_bad_param;
476 
477 	shm = optee_shm_from_ffa_handle(optee, arg->params[0].u.value.b);
478 	if (!shm)
479 		goto err_bad_param;
480 	switch (arg->params[0].u.value.a) {
481 	case OPTEE_RPC_SHM_TYPE_APPL:
482 		optee_rpc_cmd_free_suppl(ctx, shm);
483 		break;
484 	case OPTEE_RPC_SHM_TYPE_KERNEL:
485 		tee_shm_free(shm);
486 		break;
487 	default:
488 		goto err_bad_param;
489 	}
490 	arg->ret = TEEC_SUCCESS;
491 	return;
492 
493 err_bad_param:
494 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
495 }
496 
497 static void handle_ffa_rpc_func_cmd(struct tee_context *ctx,
498 				    struct optee *optee,
499 				    struct optee_msg_arg *arg)
500 {
501 	arg->ret_origin = TEEC_ORIGIN_COMMS;
502 	switch (arg->cmd) {
503 	case OPTEE_RPC_CMD_SHM_ALLOC:
504 		handle_ffa_rpc_func_cmd_shm_alloc(ctx, optee, arg);
505 		break;
506 	case OPTEE_RPC_CMD_SHM_FREE:
507 		handle_ffa_rpc_func_cmd_shm_free(ctx, optee, arg);
508 		break;
509 	default:
510 		optee_rpc_cmd(ctx, optee, arg);
511 	}
512 }
513 
514 static void optee_handle_ffa_rpc(struct tee_context *ctx, struct optee *optee,
515 				 u32 cmd, struct optee_msg_arg *arg)
516 {
517 	switch (cmd) {
518 	case OPTEE_FFA_YIELDING_CALL_RETURN_RPC_CMD:
519 		handle_ffa_rpc_func_cmd(ctx, optee, arg);
520 		break;
521 	case OPTEE_FFA_YIELDING_CALL_RETURN_INTERRUPT:
522 		/* Interrupt delivered by now */
523 		break;
524 	default:
525 		pr_warn("Unknown RPC func 0x%x\n", cmd);
526 		break;
527 	}
528 }
529 
530 static int optee_ffa_yielding_call(struct tee_context *ctx,
531 				   struct ffa_send_direct_data *data,
532 				   struct optee_msg_arg *rpc_arg,
533 				   bool system_thread)
534 {
535 	struct optee *optee = tee_get_drvdata(ctx->teedev);
536 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
537 	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
538 	struct optee_call_waiter w;
539 	u32 cmd = data->data0;
540 	u32 w4 = data->data1;
541 	u32 w5 = data->data2;
542 	u32 w6 = data->data3;
543 	int rc;
544 
545 	/* Initialize waiter */
546 	optee_cq_wait_init(&optee->call_queue, &w, system_thread);
547 	while (true) {
548 		rc = msg_ops->sync_send_receive(ffa_dev, data);
549 		if (rc)
550 			goto done;
551 
552 		switch ((int)data->data0) {
553 		case TEEC_SUCCESS:
554 			break;
555 		case TEEC_ERROR_BUSY:
556 			if (cmd == OPTEE_FFA_YIELDING_CALL_RESUME) {
557 				rc = -EIO;
558 				goto done;
559 			}
560 
561 			/*
562 			 * Out of threads in secure world, wait for a thread
563 			 * become available.
564 			 */
565 			optee_cq_wait_for_completion(&optee->call_queue, &w);
566 			data->data0 = cmd;
567 			data->data1 = w4;
568 			data->data2 = w5;
569 			data->data3 = w6;
570 			continue;
571 		default:
572 			rc = -EIO;
573 			goto done;
574 		}
575 
576 		if (data->data1 == OPTEE_FFA_YIELDING_CALL_RETURN_DONE)
577 			goto done;
578 
579 		/*
580 		 * OP-TEE has returned with a RPC request.
581 		 *
582 		 * Note that data->data4 (passed in register w7) is already
583 		 * filled in by ffa_mem_ops->sync_send_receive() returning
584 		 * above.
585 		 */
586 		cond_resched();
587 		optee_handle_ffa_rpc(ctx, optee, data->data1, rpc_arg);
588 		cmd = OPTEE_FFA_YIELDING_CALL_RESUME;
589 		data->data0 = cmd;
590 		data->data1 = 0;
591 		data->data2 = 0;
592 		data->data3 = 0;
593 	}
594 done:
595 	/*
596 	 * We're done with our thread in secure world, if there's any
597 	 * thread waiters wake up one.
598 	 */
599 	optee_cq_wait_final(&optee->call_queue, &w);
600 
601 	return rc;
602 }
603 
604 /**
605  * optee_ffa_do_call_with_arg() - Do a FF-A call to enter OP-TEE in secure world
606  * @ctx:	calling context
607  * @shm:	shared memory holding the message to pass to secure world
608  * @offs:	offset of the message in @shm
609  * @system_thread: true if caller requests TEE system thread support
610  *
611  * Does a FF-A call to OP-TEE in secure world and handles eventual resulting
612  * Remote Procedure Calls (RPC) from OP-TEE.
613  *
614  * Returns return code from FF-A, 0 is OK
615  */
616 
617 static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
618 				      struct tee_shm *shm, u_int offs,
619 				      bool system_thread)
620 {
621 	struct ffa_send_direct_data data = {
622 		.data0 = OPTEE_FFA_YIELDING_CALL_WITH_ARG,
623 		.data1 = (u32)shm->sec_world_id,
624 		.data2 = (u32)(shm->sec_world_id >> 32),
625 		.data3 = offs,
626 	};
627 	struct optee_msg_arg *arg;
628 	unsigned int rpc_arg_offs;
629 	struct optee_msg_arg *rpc_arg;
630 
631 	/*
632 	 * The shared memory object has to start on a page when passed as
633 	 * an argument struct. This is also what the shm pool allocator
634 	 * returns, but check this before calling secure world to catch
635 	 * eventual errors early in case something changes.
636 	 */
637 	if (shm->offset)
638 		return -EINVAL;
639 
640 	arg = tee_shm_get_va(shm, offs);
641 	if (IS_ERR(arg))
642 		return PTR_ERR(arg);
643 
644 	rpc_arg_offs = OPTEE_MSG_GET_ARG_SIZE(arg->num_params);
645 	rpc_arg = tee_shm_get_va(shm, offs + rpc_arg_offs);
646 	if (IS_ERR(rpc_arg))
647 		return PTR_ERR(rpc_arg);
648 
649 	return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
650 }
651 
652 /*
653  * 6. Driver initialization
654  *
655  * During driver inititialization is the OP-TEE Secure Partition is probed
656  * to find out which features it supports so the driver can be initialized
657  * with a matching configuration.
658  */
659 
660 static bool optee_ffa_api_is_compatbile(struct ffa_device *ffa_dev,
661 					const struct ffa_ops *ops)
662 {
663 	const struct ffa_msg_ops *msg_ops = ops->msg_ops;
664 	struct ffa_send_direct_data data = {
665 		.data0 = OPTEE_FFA_GET_API_VERSION,
666 	};
667 	int rc;
668 
669 	msg_ops->mode_32bit_set(ffa_dev);
670 
671 	rc = msg_ops->sync_send_receive(ffa_dev, &data);
672 	if (rc) {
673 		pr_err("Unexpected error %d\n", rc);
674 		return false;
675 	}
676 	if (data.data0 != OPTEE_FFA_VERSION_MAJOR ||
677 	    data.data1 < OPTEE_FFA_VERSION_MINOR) {
678 		pr_err("Incompatible OP-TEE API version %lu.%lu",
679 		       data.data0, data.data1);
680 		return false;
681 	}
682 
683 	data = (struct ffa_send_direct_data){
684 		.data0 = OPTEE_FFA_GET_OS_VERSION,
685 	};
686 	rc = msg_ops->sync_send_receive(ffa_dev, &data);
687 	if (rc) {
688 		pr_err("Unexpected error %d\n", rc);
689 		return false;
690 	}
691 	if (data.data2)
692 		pr_info("revision %lu.%lu (%08lx)",
693 			data.data0, data.data1, data.data2);
694 	else
695 		pr_info("revision %lu.%lu", data.data0, data.data1);
696 
697 	return true;
698 }
699 
700 static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
701 				    const struct ffa_ops *ops,
702 				    u32 *sec_caps,
703 				    unsigned int *rpc_param_count,
704 				    unsigned int *max_notif_value)
705 {
706 	struct ffa_send_direct_data data = {
707 		.data0 = OPTEE_FFA_EXCHANGE_CAPABILITIES,
708 	};
709 	int rc;
710 
711 	rc = ops->msg_ops->sync_send_receive(ffa_dev, &data);
712 	if (rc) {
713 		pr_err("Unexpected error %d", rc);
714 		return false;
715 	}
716 	if (data.data0) {
717 		pr_err("Unexpected exchange error %lu", data.data0);
718 		return false;
719 	}
720 
721 	*rpc_param_count = (u8)data.data1;
722 	*sec_caps = data.data2;
723 	if (data.data3)
724 		*max_notif_value = data.data3;
725 	else
726 		*max_notif_value = OPTEE_DEFAULT_MAX_NOTIF_VALUE;
727 
728 	return true;
729 }
730 
731 static void notif_callback(int notify_id, void *cb_data)
732 {
733 	struct optee *optee = cb_data;
734 
735 	if (notify_id == optee->ffa.bottom_half_value)
736 		optee_do_bottom_half(optee->ctx);
737 	else
738 		optee_notif_send(optee, notify_id);
739 }
740 
741 static int enable_async_notif(struct optee *optee)
742 {
743 	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
744 	struct ffa_send_direct_data data = {
745 		.data0 = OPTEE_FFA_ENABLE_ASYNC_NOTIF,
746 		.data1 = optee->ffa.bottom_half_value,
747 	};
748 	int rc;
749 
750 	rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &data);
751 	if (rc)
752 		return rc;
753 	return data.data0;
754 }
755 
756 static void optee_ffa_get_version(struct tee_device *teedev,
757 				  struct tee_ioctl_version_data *vers)
758 {
759 	struct tee_ioctl_version_data v = {
760 		.impl_id = TEE_IMPL_ID_OPTEE,
761 		.impl_caps = TEE_OPTEE_CAP_TZ,
762 		.gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
763 			    TEE_GEN_CAP_MEMREF_NULL,
764 	};
765 
766 	*vers = v;
767 }
768 
769 static int optee_ffa_open(struct tee_context *ctx)
770 {
771 	return optee_open(ctx, true);
772 }
773 
774 static const struct tee_driver_ops optee_ffa_clnt_ops = {
775 	.get_version = optee_ffa_get_version,
776 	.open = optee_ffa_open,
777 	.release = optee_release,
778 	.open_session = optee_open_session,
779 	.close_session = optee_close_session,
780 	.invoke_func = optee_invoke_func,
781 	.cancel_req = optee_cancel_req,
782 	.shm_register = optee_ffa_shm_register,
783 	.shm_unregister = optee_ffa_shm_unregister,
784 };
785 
786 static const struct tee_desc optee_ffa_clnt_desc = {
787 	.name = DRIVER_NAME "-ffa-clnt",
788 	.ops = &optee_ffa_clnt_ops,
789 	.owner = THIS_MODULE,
790 };
791 
792 static const struct tee_driver_ops optee_ffa_supp_ops = {
793 	.get_version = optee_ffa_get_version,
794 	.open = optee_ffa_open,
795 	.release = optee_release_supp,
796 	.supp_recv = optee_supp_recv,
797 	.supp_send = optee_supp_send,
798 	.shm_register = optee_ffa_shm_register, /* same as for clnt ops */
799 	.shm_unregister = optee_ffa_shm_unregister_supp,
800 };
801 
802 static const struct tee_desc optee_ffa_supp_desc = {
803 	.name = DRIVER_NAME "-ffa-supp",
804 	.ops = &optee_ffa_supp_ops,
805 	.owner = THIS_MODULE,
806 	.flags = TEE_DESC_PRIVILEGED,
807 };
808 
809 static const struct optee_ops optee_ffa_ops = {
810 	.do_call_with_arg = optee_ffa_do_call_with_arg,
811 	.to_msg_param = optee_ffa_to_msg_param,
812 	.from_msg_param = optee_ffa_from_msg_param,
813 };
814 
815 static void optee_ffa_remove(struct ffa_device *ffa_dev)
816 {
817 	struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
818 	u32 bottom_half_id = optee->ffa.bottom_half_value;
819 
820 	if (bottom_half_id != U32_MAX)
821 		ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev,
822 							      bottom_half_id);
823 	optee_remove_common(optee);
824 
825 	mutex_destroy(&optee->ffa.mutex);
826 	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
827 
828 	kfree(optee);
829 }
830 
831 static int optee_ffa_async_notif_init(struct ffa_device *ffa_dev,
832 				      struct optee *optee)
833 {
834 	bool is_per_vcpu = false;
835 	u32 notif_id = 0;
836 	int rc;
837 
838 	while (true) {
839 		rc = ffa_dev->ops->notifier_ops->notify_request(ffa_dev,
840 								is_per_vcpu,
841 								notif_callback,
842 								optee,
843 								notif_id);
844 		if (!rc)
845 			break;
846 		/*
847 		 * -EACCES means that the notification ID was
848 		 * already bound, try the next one as long as we
849 		 * haven't reached the max. Any other error is a
850 		 * permanent error, so skip asynchronous
851 		 * notifications in that case.
852 		 */
853 		if (rc != -EACCES)
854 			return rc;
855 		notif_id++;
856 		if (notif_id >= OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE)
857 			return rc;
858 	}
859 	optee->ffa.bottom_half_value = notif_id;
860 
861 	rc = enable_async_notif(optee);
862 	if (rc < 0) {
863 		ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev,
864 							      notif_id);
865 		optee->ffa.bottom_half_value = U32_MAX;
866 	}
867 
868 	return rc;
869 }
870 
871 static int optee_ffa_probe(struct ffa_device *ffa_dev)
872 {
873 	const struct ffa_notifier_ops *notif_ops;
874 	const struct ffa_ops *ffa_ops;
875 	unsigned int max_notif_value;
876 	unsigned int rpc_param_count;
877 	struct tee_shm_pool *pool;
878 	struct tee_device *teedev;
879 	struct tee_context *ctx;
880 	u32 arg_cache_flags = 0;
881 	struct optee *optee;
882 	u32 sec_caps;
883 	int rc;
884 
885 	ffa_ops = ffa_dev->ops;
886 	notif_ops = ffa_ops->notifier_ops;
887 
888 	if (!optee_ffa_api_is_compatbile(ffa_dev, ffa_ops))
889 		return -EINVAL;
890 
891 	if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
892 				     &rpc_param_count, &max_notif_value))
893 		return -EINVAL;
894 	if (sec_caps & OPTEE_FFA_SEC_CAP_ARG_OFFSET)
895 		arg_cache_flags |= OPTEE_SHM_ARG_SHARED;
896 
897 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
898 	if (!optee)
899 		return -ENOMEM;
900 
901 	pool = optee_ffa_shm_pool_alloc_pages();
902 	if (IS_ERR(pool)) {
903 		rc = PTR_ERR(pool);
904 		goto err_free_optee;
905 	}
906 	optee->pool = pool;
907 
908 	optee->ops = &optee_ffa_ops;
909 	optee->ffa.ffa_dev = ffa_dev;
910 	optee->ffa.bottom_half_value = U32_MAX;
911 	optee->rpc_param_count = rpc_param_count;
912 
913 	if (IS_REACHABLE(CONFIG_RPMB) &&
914 	    (sec_caps & OPTEE_FFA_SEC_CAP_RPMB_PROBE))
915 		optee->in_kernel_rpmb_routing = true;
916 
917 	teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
918 				  optee);
919 	if (IS_ERR(teedev)) {
920 		rc = PTR_ERR(teedev);
921 		goto err_free_pool;
922 	}
923 	optee->teedev = teedev;
924 
925 	teedev = tee_device_alloc(&optee_ffa_supp_desc, NULL, optee->pool,
926 				  optee);
927 	if (IS_ERR(teedev)) {
928 		rc = PTR_ERR(teedev);
929 		goto err_unreg_teedev;
930 	}
931 	optee->supp_teedev = teedev;
932 
933 	optee_set_dev_group(optee);
934 
935 	rc = tee_device_register(optee->teedev);
936 	if (rc)
937 		goto err_unreg_supp_teedev;
938 
939 	rc = tee_device_register(optee->supp_teedev);
940 	if (rc)
941 		goto err_unreg_supp_teedev;
942 
943 	rc = rhashtable_init(&optee->ffa.global_ids, &shm_rhash_params);
944 	if (rc)
945 		goto err_unreg_supp_teedev;
946 	mutex_init(&optee->ffa.mutex);
947 	optee_cq_init(&optee->call_queue, 0);
948 	optee_supp_init(&optee->supp);
949 	optee_shm_arg_cache_init(optee, arg_cache_flags);
950 	mutex_init(&optee->rpmb_dev_mutex);
951 	ffa_dev_set_drvdata(ffa_dev, optee);
952 	ctx = teedev_open(optee->teedev);
953 	if (IS_ERR(ctx)) {
954 		rc = PTR_ERR(ctx);
955 		goto err_rhashtable_free;
956 	}
957 	optee->ctx = ctx;
958 	rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
959 	if (rc)
960 		goto err_close_ctx;
961 	if (sec_caps & OPTEE_FFA_SEC_CAP_ASYNC_NOTIF) {
962 		rc = optee_ffa_async_notif_init(ffa_dev, optee);
963 		if (rc < 0)
964 			pr_err("Failed to initialize async notifications: %d",
965 			       rc);
966 	}
967 
968 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
969 	if (rc)
970 		goto err_unregister_devices;
971 
972 	INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
973 	optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
974 	blocking_notifier_chain_register(&optee_rpmb_intf_added,
975 					 &optee->rpmb_intf);
976 	pr_info("initialized driver\n");
977 	return 0;
978 
979 err_unregister_devices:
980 	optee_unregister_devices();
981 	if (optee->ffa.bottom_half_value != U32_MAX)
982 		notif_ops->notify_relinquish(ffa_dev,
983 					     optee->ffa.bottom_half_value);
984 	optee_notif_uninit(optee);
985 err_close_ctx:
986 	teedev_close_context(ctx);
987 err_rhashtable_free:
988 	rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
989 	rpmb_dev_put(optee->rpmb_dev);
990 	mutex_destroy(&optee->rpmb_dev_mutex);
991 	optee_supp_uninit(&optee->supp);
992 	mutex_destroy(&optee->call_queue.mutex);
993 	mutex_destroy(&optee->ffa.mutex);
994 err_unreg_supp_teedev:
995 	tee_device_unregister(optee->supp_teedev);
996 err_unreg_teedev:
997 	tee_device_unregister(optee->teedev);
998 err_free_pool:
999 	tee_shm_pool_free(pool);
1000 err_free_optee:
1001 	kfree(optee);
1002 	return rc;
1003 }
1004 
1005 static const struct ffa_device_id optee_ffa_device_id[] = {
1006 	/* 486178e0-e7f8-11e3-bc5e0002a5d5c51b */
1007 	{ UUID_INIT(0x486178e0, 0xe7f8, 0x11e3,
1008 		    0xbc, 0x5e, 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b) },
1009 	{}
1010 };
1011 
1012 static struct ffa_driver optee_ffa_driver = {
1013 	.name = "optee",
1014 	.probe = optee_ffa_probe,
1015 	.remove = optee_ffa_remove,
1016 	.id_table = optee_ffa_device_id,
1017 };
1018 
1019 int optee_ffa_abi_register(void)
1020 {
1021 	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
1022 		return ffa_register(&optee_ffa_driver);
1023 	else
1024 		return -EOPNOTSUPP;
1025 }
1026 
1027 void optee_ffa_abi_unregister(void)
1028 {
1029 	if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
1030 		ffa_unregister(&optee_ffa_driver);
1031 }
1032