xref: /openbmc/linux/drivers/tee/optee/core.c (revision 93707cbabcc8baf2b2b5f4a99c1f08ee83eb7abd)
1 /*
2  * Copyright (c) 2015, Linaro Limited
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 
17 #include <linux/arm-smccc.h>
18 #include <linux/errno.h>
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/of_platform.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/string.h>
26 #include <linux/tee_drv.h>
27 #include <linux/types.h>
28 #include <linux/uaccess.h>
29 #include "optee_private.h"
30 #include "optee_smc.h"
31 #include "shm_pool.h"
32 
33 #define DRIVER_NAME "optee"
34 
35 #define OPTEE_SHM_NUM_PRIV_PAGES	1
36 
37 /**
38  * optee_from_msg_param() - convert from OPTEE_MSG parameters to
39  *			    struct tee_param
40  * @params:	subsystem internal parameter representation
41  * @num_params:	number of elements in the parameter arrays
42  * @msg_params:	OPTEE_MSG parameters
43  * Returns 0 on success or <0 on failure
44  */
45 int optee_from_msg_param(struct tee_param *params, size_t num_params,
46 			 const struct optee_msg_param *msg_params)
47 {
48 	int rc;
49 	size_t n;
50 	struct tee_shm *shm;
51 	phys_addr_t pa;
52 
53 	for (n = 0; n < num_params; n++) {
54 		struct tee_param *p = params + n;
55 		const struct optee_msg_param *mp = msg_params + n;
56 		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
57 
58 		switch (attr) {
59 		case OPTEE_MSG_ATTR_TYPE_NONE:
60 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
61 			memset(&p->u, 0, sizeof(p->u));
62 			break;
63 		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
64 		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
65 		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
66 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
67 				  attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
68 			p->u.value.a = mp->u.value.a;
69 			p->u.value.b = mp->u.value.b;
70 			p->u.value.c = mp->u.value.c;
71 			break;
72 		case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
73 		case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
74 		case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
75 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
76 				  attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
77 			p->u.memref.size = mp->u.tmem.size;
78 			shm = (struct tee_shm *)(unsigned long)
79 				mp->u.tmem.shm_ref;
80 			if (!shm) {
81 				p->u.memref.shm_offs = 0;
82 				p->u.memref.shm = NULL;
83 				break;
84 			}
85 			rc = tee_shm_get_pa(shm, 0, &pa);
86 			if (rc)
87 				return rc;
88 			p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
89 			p->u.memref.shm = shm;
90 
91 			/* Check that the memref is covered by the shm object */
92 			if (p->u.memref.size) {
93 				size_t o = p->u.memref.shm_offs +
94 					   p->u.memref.size - 1;
95 
96 				rc = tee_shm_get_pa(shm, o, NULL);
97 				if (rc)
98 					return rc;
99 			}
100 			break;
101 		case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
102 		case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
103 		case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
104 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
105 				  attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
106 			p->u.memref.size = mp->u.rmem.size;
107 			shm = (struct tee_shm *)(unsigned long)
108 				mp->u.rmem.shm_ref;
109 
110 			if (!shm) {
111 				p->u.memref.shm_offs = 0;
112 				p->u.memref.shm = NULL;
113 				break;
114 			}
115 			p->u.memref.shm_offs = mp->u.rmem.offs;
116 			p->u.memref.shm = shm;
117 
118 			break;
119 
120 		default:
121 			return -EINVAL;
122 		}
123 	}
124 	return 0;
125 }
126 
127 static int to_msg_param_tmp_mem(struct optee_msg_param *mp,
128 				const struct tee_param *p)
129 {
130 	int rc;
131 	phys_addr_t pa;
132 
133 	mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT + p->attr -
134 		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
135 
136 	mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
137 	mp->u.tmem.size = p->u.memref.size;
138 
139 	if (!p->u.memref.shm) {
140 		mp->u.tmem.buf_ptr = 0;
141 		return 0;
142 	}
143 
144 	rc = tee_shm_get_pa(p->u.memref.shm, p->u.memref.shm_offs, &pa);
145 	if (rc)
146 		return rc;
147 
148 	mp->u.tmem.buf_ptr = pa;
149 	mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
150 		    OPTEE_MSG_ATTR_CACHE_SHIFT;
151 
152 	return 0;
153 }
154 
155 static int to_msg_param_reg_mem(struct optee_msg_param *mp,
156 				const struct tee_param *p)
157 {
158 	mp->attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT + p->attr -
159 		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
160 
161 	mp->u.rmem.shm_ref = (unsigned long)p->u.memref.shm;
162 	mp->u.rmem.size = p->u.memref.size;
163 	mp->u.rmem.offs = p->u.memref.shm_offs;
164 	return 0;
165 }
166 
167 /**
168  * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
169  * @msg_params:	OPTEE_MSG parameters
170  * @num_params:	number of elements in the parameter arrays
171  * @params:	subsystem itnernal parameter representation
172  * Returns 0 on success or <0 on failure
173  */
174 int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
175 		       const struct tee_param *params)
176 {
177 	int rc;
178 	size_t n;
179 
180 	for (n = 0; n < num_params; n++) {
181 		const struct tee_param *p = params + n;
182 		struct optee_msg_param *mp = msg_params + n;
183 
184 		switch (p->attr) {
185 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
186 			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
187 			memset(&mp->u, 0, sizeof(mp->u));
188 			break;
189 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
190 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
191 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
192 			mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
193 				   TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
194 			mp->u.value.a = p->u.value.a;
195 			mp->u.value.b = p->u.value.b;
196 			mp->u.value.c = p->u.value.c;
197 			break;
198 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
199 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
200 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
201 			if (tee_shm_is_registered(p->u.memref.shm))
202 				rc = to_msg_param_reg_mem(mp, p);
203 			else
204 				rc = to_msg_param_tmp_mem(mp, p);
205 			if (rc)
206 				return rc;
207 			break;
208 		default:
209 			return -EINVAL;
210 		}
211 	}
212 	return 0;
213 }
214 
215 static void optee_get_version(struct tee_device *teedev,
216 			      struct tee_ioctl_version_data *vers)
217 {
218 	struct tee_ioctl_version_data v = {
219 		.impl_id = TEE_IMPL_ID_OPTEE,
220 		.impl_caps = TEE_OPTEE_CAP_TZ,
221 		.gen_caps = TEE_GEN_CAP_GP,
222 	};
223 	struct optee *optee = tee_get_drvdata(teedev);
224 
225 	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
226 		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
227 	*vers = v;
228 }
229 
230 static int optee_open(struct tee_context *ctx)
231 {
232 	struct optee_context_data *ctxdata;
233 	struct tee_device *teedev = ctx->teedev;
234 	struct optee *optee = tee_get_drvdata(teedev);
235 
236 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
237 	if (!ctxdata)
238 		return -ENOMEM;
239 
240 	if (teedev == optee->supp_teedev) {
241 		bool busy = true;
242 
243 		mutex_lock(&optee->supp.mutex);
244 		if (!optee->supp.ctx) {
245 			busy = false;
246 			optee->supp.ctx = ctx;
247 		}
248 		mutex_unlock(&optee->supp.mutex);
249 		if (busy) {
250 			kfree(ctxdata);
251 			return -EBUSY;
252 		}
253 	}
254 
255 	mutex_init(&ctxdata->mutex);
256 	INIT_LIST_HEAD(&ctxdata->sess_list);
257 
258 	ctx->data = ctxdata;
259 	return 0;
260 }
261 
262 static void optee_release(struct tee_context *ctx)
263 {
264 	struct optee_context_data *ctxdata = ctx->data;
265 	struct tee_device *teedev = ctx->teedev;
266 	struct optee *optee = tee_get_drvdata(teedev);
267 	struct tee_shm *shm;
268 	struct optee_msg_arg *arg = NULL;
269 	phys_addr_t parg;
270 	struct optee_session *sess;
271 	struct optee_session *sess_tmp;
272 
273 	if (!ctxdata)
274 		return;
275 
276 	shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), TEE_SHM_MAPPED);
277 	if (!IS_ERR(shm)) {
278 		arg = tee_shm_get_va(shm, 0);
279 		/*
280 		 * If va2pa fails for some reason, we can't call into
281 		 * secure world, only free the memory. Secure OS will leak
282 		 * sessions and finally refuse more sessions, but we will
283 		 * at least let normal world reclaim its memory.
284 		 */
285 		if (!IS_ERR(arg))
286 			if (tee_shm_va2pa(shm, arg, &parg))
287 				arg = NULL; /* prevent usage of parg below */
288 	}
289 
290 	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
291 				 list_node) {
292 		list_del(&sess->list_node);
293 		if (!IS_ERR_OR_NULL(arg)) {
294 			memset(arg, 0, sizeof(*arg));
295 			arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
296 			arg->session = sess->session_id;
297 			optee_do_call_with_arg(ctx, parg);
298 		}
299 		kfree(sess);
300 	}
301 	kfree(ctxdata);
302 
303 	if (!IS_ERR(shm))
304 		tee_shm_free(shm);
305 
306 	ctx->data = NULL;
307 
308 	if (teedev == optee->supp_teedev)
309 		optee_supp_release(&optee->supp);
310 }
311 
312 static const struct tee_driver_ops optee_ops = {
313 	.get_version = optee_get_version,
314 	.open = optee_open,
315 	.release = optee_release,
316 	.open_session = optee_open_session,
317 	.close_session = optee_close_session,
318 	.invoke_func = optee_invoke_func,
319 	.cancel_req = optee_cancel_req,
320 	.shm_register = optee_shm_register,
321 	.shm_unregister = optee_shm_unregister,
322 };
323 
324 static const struct tee_desc optee_desc = {
325 	.name = DRIVER_NAME "-clnt",
326 	.ops = &optee_ops,
327 	.owner = THIS_MODULE,
328 };
329 
330 static const struct tee_driver_ops optee_supp_ops = {
331 	.get_version = optee_get_version,
332 	.open = optee_open,
333 	.release = optee_release,
334 	.supp_recv = optee_supp_recv,
335 	.supp_send = optee_supp_send,
336 	.shm_register = optee_shm_register_supp,
337 	.shm_unregister = optee_shm_unregister_supp,
338 };
339 
340 static const struct tee_desc optee_supp_desc = {
341 	.name = DRIVER_NAME "-supp",
342 	.ops = &optee_supp_ops,
343 	.owner = THIS_MODULE,
344 	.flags = TEE_DESC_PRIVILEGED,
345 };
346 
347 static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
348 {
349 	struct arm_smccc_res res;
350 
351 	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);
352 
353 	if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
354 	    res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
355 		return true;
356 	return false;
357 }
358 
359 static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
360 {
361 	union {
362 		struct arm_smccc_res smccc;
363 		struct optee_smc_calls_revision_result result;
364 	} res;
365 
366 	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
367 
368 	if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
369 	    (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
370 		return true;
371 	return false;
372 }
373 
374 static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
375 					    u32 *sec_caps)
376 {
377 	union {
378 		struct arm_smccc_res smccc;
379 		struct optee_smc_exchange_capabilities_result result;
380 	} res;
381 	u32 a1 = 0;
382 
383 	/*
384 	 * TODO This isn't enough to tell if it's UP system (from kernel
385 	 * point of view) or not, is_smp() returns the the information
386 	 * needed, but can't be called directly from here.
387 	 */
388 	if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
389 		a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;
390 
391 	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
392 		  &res.smccc);
393 
394 	if (res.result.status != OPTEE_SMC_RETURN_OK)
395 		return false;
396 
397 	*sec_caps = res.result.capabilities;
398 	return true;
399 }
400 
401 static struct tee_shm_pool *
402 optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm,
403 			  u32 sec_caps)
404 {
405 	union {
406 		struct arm_smccc_res smccc;
407 		struct optee_smc_get_shm_config_result result;
408 	} res;
409 	unsigned long vaddr;
410 	phys_addr_t paddr;
411 	size_t size;
412 	phys_addr_t begin;
413 	phys_addr_t end;
414 	void *va;
415 	struct tee_shm_pool_mgr *priv_mgr;
416 	struct tee_shm_pool_mgr *dmabuf_mgr;
417 	void *rc;
418 
419 	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
420 	if (res.result.status != OPTEE_SMC_RETURN_OK) {
421 		pr_info("shm service not available\n");
422 		return ERR_PTR(-ENOENT);
423 	}
424 
425 	if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
426 		pr_err("only normal cached shared memory supported\n");
427 		return ERR_PTR(-EINVAL);
428 	}
429 
430 	begin = roundup(res.result.start, PAGE_SIZE);
431 	end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
432 	paddr = begin;
433 	size = end - begin;
434 
435 	if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
436 		pr_err("too small shared memory area\n");
437 		return ERR_PTR(-EINVAL);
438 	}
439 
440 	va = memremap(paddr, size, MEMREMAP_WB);
441 	if (!va) {
442 		pr_err("shared memory ioremap failed\n");
443 		return ERR_PTR(-EINVAL);
444 	}
445 	vaddr = (unsigned long)va;
446 
447 	/*
448 	 * If OP-TEE can work with unregistered SHM, we will use own pool
449 	 * for private shm
450 	 */
451 	if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) {
452 		rc = optee_shm_pool_alloc_pages();
453 		if (IS_ERR(rc))
454 			goto err_memunmap;
455 		priv_mgr = rc;
456 	} else {
457 		const size_t sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
458 
459 		rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, sz,
460 						    3 /* 8 bytes aligned */);
461 		if (IS_ERR(rc))
462 			goto err_memunmap;
463 		priv_mgr = rc;
464 
465 		vaddr += sz;
466 		paddr += sz;
467 		size -= sz;
468 	}
469 
470 	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, size, PAGE_SHIFT);
471 	if (IS_ERR(rc))
472 		goto err_free_priv_mgr;
473 	dmabuf_mgr = rc;
474 
475 	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
476 	if (IS_ERR(rc))
477 		goto err_free_dmabuf_mgr;
478 
479 	*memremaped_shm = va;
480 
481 	return rc;
482 
483 err_free_dmabuf_mgr:
484 	tee_shm_pool_mgr_destroy(dmabuf_mgr);
485 err_free_priv_mgr:
486 	tee_shm_pool_mgr_destroy(priv_mgr);
487 err_memunmap:
488 	memunmap(va);
489 	return rc;
490 }
491 
492 /* Simple wrapper functions to be able to use a function pointer */
493 static void optee_smccc_smc(unsigned long a0, unsigned long a1,
494 			    unsigned long a2, unsigned long a3,
495 			    unsigned long a4, unsigned long a5,
496 			    unsigned long a6, unsigned long a7,
497 			    struct arm_smccc_res *res)
498 {
499 	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
500 }
501 
502 static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
503 			    unsigned long a2, unsigned long a3,
504 			    unsigned long a4, unsigned long a5,
505 			    unsigned long a6, unsigned long a7,
506 			    struct arm_smccc_res *res)
507 {
508 	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
509 }
510 
511 static optee_invoke_fn *get_invoke_func(struct device_node *np)
512 {
513 	const char *method;
514 
515 	pr_info("probing for conduit method from DT.\n");
516 
517 	if (of_property_read_string(np, "method", &method)) {
518 		pr_warn("missing \"method\" property\n");
519 		return ERR_PTR(-ENXIO);
520 	}
521 
522 	if (!strcmp("hvc", method))
523 		return optee_smccc_hvc;
524 	else if (!strcmp("smc", method))
525 		return optee_smccc_smc;
526 
527 	pr_warn("invalid \"method\" property: %s\n", method);
528 	return ERR_PTR(-EINVAL);
529 }
530 
531 static struct optee *optee_probe(struct device_node *np)
532 {
533 	optee_invoke_fn *invoke_fn;
534 	struct tee_shm_pool *pool;
535 	struct optee *optee = NULL;
536 	void *memremaped_shm = NULL;
537 	struct tee_device *teedev;
538 	u32 sec_caps;
539 	int rc;
540 
541 	invoke_fn = get_invoke_func(np);
542 	if (IS_ERR(invoke_fn))
543 		return (void *)invoke_fn;
544 
545 	if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
546 		pr_warn("api uid mismatch\n");
547 		return ERR_PTR(-EINVAL);
548 	}
549 
550 	if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
551 		pr_warn("api revision mismatch\n");
552 		return ERR_PTR(-EINVAL);
553 	}
554 
555 	if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) {
556 		pr_warn("capabilities mismatch\n");
557 		return ERR_PTR(-EINVAL);
558 	}
559 
560 	/*
561 	 * We have no other option for shared memory, if secure world
562 	 * doesn't have any reserved memory we can use we can't continue.
563 	 */
564 	if (!(sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
565 		return ERR_PTR(-EINVAL);
566 
567 	pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm, sec_caps);
568 	if (IS_ERR(pool))
569 		return (void *)pool;
570 
571 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
572 	if (!optee) {
573 		rc = -ENOMEM;
574 		goto err;
575 	}
576 
577 	optee->invoke_fn = invoke_fn;
578 	optee->sec_caps = sec_caps;
579 
580 	teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
581 	if (IS_ERR(teedev)) {
582 		rc = PTR_ERR(teedev);
583 		goto err;
584 	}
585 	optee->teedev = teedev;
586 
587 	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
588 	if (IS_ERR(teedev)) {
589 		rc = PTR_ERR(teedev);
590 		goto err;
591 	}
592 	optee->supp_teedev = teedev;
593 
594 	rc = tee_device_register(optee->teedev);
595 	if (rc)
596 		goto err;
597 
598 	rc = tee_device_register(optee->supp_teedev);
599 	if (rc)
600 		goto err;
601 
602 	mutex_init(&optee->call_queue.mutex);
603 	INIT_LIST_HEAD(&optee->call_queue.waiters);
604 	optee_wait_queue_init(&optee->wait_queue);
605 	optee_supp_init(&optee->supp);
606 	optee->memremaped_shm = memremaped_shm;
607 	optee->pool = pool;
608 
609 	optee_enable_shm_cache(optee);
610 
611 	pr_info("initialized driver\n");
612 	return optee;
613 err:
614 	if (optee) {
615 		/*
616 		 * tee_device_unregister() is safe to call even if the
617 		 * devices hasn't been registered with
618 		 * tee_device_register() yet.
619 		 */
620 		tee_device_unregister(optee->supp_teedev);
621 		tee_device_unregister(optee->teedev);
622 		kfree(optee);
623 	}
624 	if (pool)
625 		tee_shm_pool_free(pool);
626 	if (memremaped_shm)
627 		memunmap(memremaped_shm);
628 	return ERR_PTR(rc);
629 }
630 
631 static void optee_remove(struct optee *optee)
632 {
633 	/*
634 	 * Ask OP-TEE to free all cached shared memory objects to decrease
635 	 * reference counters and also avoid wild pointers in secure world
636 	 * into the old shared memory range.
637 	 */
638 	optee_disable_shm_cache(optee);
639 
640 	/*
641 	 * The two devices has to be unregistered before we can free the
642 	 * other resources.
643 	 */
644 	tee_device_unregister(optee->supp_teedev);
645 	tee_device_unregister(optee->teedev);
646 
647 	tee_shm_pool_free(optee->pool);
648 	if (optee->memremaped_shm)
649 		memunmap(optee->memremaped_shm);
650 	optee_wait_queue_exit(&optee->wait_queue);
651 	optee_supp_uninit(&optee->supp);
652 	mutex_destroy(&optee->call_queue.mutex);
653 
654 	kfree(optee);
655 }
656 
657 static const struct of_device_id optee_match[] = {
658 	{ .compatible = "linaro,optee-tz" },
659 	{},
660 };
661 
662 static struct optee *optee_svc;
663 
664 static int __init optee_driver_init(void)
665 {
666 	struct device_node *fw_np;
667 	struct device_node *np;
668 	struct optee *optee;
669 
670 	/* Node is supposed to be below /firmware */
671 	fw_np = of_find_node_by_name(NULL, "firmware");
672 	if (!fw_np)
673 		return -ENODEV;
674 
675 	np = of_find_matching_node(fw_np, optee_match);
676 	if (!np)
677 		return -ENODEV;
678 
679 	optee = optee_probe(np);
680 	of_node_put(np);
681 
682 	if (IS_ERR(optee))
683 		return PTR_ERR(optee);
684 
685 	optee_svc = optee;
686 
687 	return 0;
688 }
689 module_init(optee_driver_init);
690 
691 static void __exit optee_driver_exit(void)
692 {
693 	struct optee *optee = optee_svc;
694 
695 	optee_svc = NULL;
696 	if (optee)
697 		optee_remove(optee);
698 }
699 module_exit(optee_driver_exit);
700 
701 MODULE_AUTHOR("Linaro");
702 MODULE_DESCRIPTION("OP-TEE driver");
703 MODULE_SUPPORTED_DEVICE("");
704 MODULE_VERSION("1.0");
705 MODULE_LICENSE("GPL v2");
706