xref: /openbmc/linux/drivers/tee/optee/core.c (revision b8b350af)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015, Linaro Limited
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/arm-smccc.h>
9 #include <linux/crash_dump.h>
10 #include <linux/errno.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/of.h>
14 #include <linux/of_platform.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/tee_drv.h>
19 #include <linux/types.h>
20 #include <linux/uaccess.h>
21 #include <linux/workqueue.h>
22 #include "optee_private.h"
23 #include "optee_smc.h"
24 #include "shm_pool.h"
25 
26 #define DRIVER_NAME "optee"
27 
28 #define OPTEE_SHM_NUM_PRIV_PAGES	CONFIG_OPTEE_SHM_NUM_PRIV_PAGES
29 
30 /**
31  * optee_from_msg_param() - convert from OPTEE_MSG parameters to
32  *			    struct tee_param
33  * @params:	subsystem internal parameter representation
34  * @num_params:	number of elements in the parameter arrays
35  * @msg_params:	OPTEE_MSG parameters
36  * Returns 0 on success or <0 on failure
37  */
38 int optee_from_msg_param(struct tee_param *params, size_t num_params,
39 			 const struct optee_msg_param *msg_params)
40 {
41 	int rc;
42 	size_t n;
43 	struct tee_shm *shm;
44 	phys_addr_t pa;
45 
46 	for (n = 0; n < num_params; n++) {
47 		struct tee_param *p = params + n;
48 		const struct optee_msg_param *mp = msg_params + n;
49 		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
50 
51 		switch (attr) {
52 		case OPTEE_MSG_ATTR_TYPE_NONE:
53 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
54 			memset(&p->u, 0, sizeof(p->u));
55 			break;
56 		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
57 		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
58 		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
59 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
60 				  attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
61 			p->u.value.a = mp->u.value.a;
62 			p->u.value.b = mp->u.value.b;
63 			p->u.value.c = mp->u.value.c;
64 			break;
65 		case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
66 		case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
67 		case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
68 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
69 				  attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
70 			p->u.memref.size = mp->u.tmem.size;
71 			shm = (struct tee_shm *)(unsigned long)
72 				mp->u.tmem.shm_ref;
73 			if (!shm) {
74 				p->u.memref.shm_offs = 0;
75 				p->u.memref.shm = NULL;
76 				break;
77 			}
78 			rc = tee_shm_get_pa(shm, 0, &pa);
79 			if (rc)
80 				return rc;
81 			p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
82 			p->u.memref.shm = shm;
83 			break;
84 		case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
85 		case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
86 		case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
87 			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
88 				  attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
89 			p->u.memref.size = mp->u.rmem.size;
90 			shm = (struct tee_shm *)(unsigned long)
91 				mp->u.rmem.shm_ref;
92 
93 			if (!shm) {
94 				p->u.memref.shm_offs = 0;
95 				p->u.memref.shm = NULL;
96 				break;
97 			}
98 			p->u.memref.shm_offs = mp->u.rmem.offs;
99 			p->u.memref.shm = shm;
100 
101 			break;
102 
103 		default:
104 			return -EINVAL;
105 		}
106 	}
107 	return 0;
108 }
109 
110 static int to_msg_param_tmp_mem(struct optee_msg_param *mp,
111 				const struct tee_param *p)
112 {
113 	int rc;
114 	phys_addr_t pa;
115 
116 	mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT + p->attr -
117 		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
118 
119 	mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
120 	mp->u.tmem.size = p->u.memref.size;
121 
122 	if (!p->u.memref.shm) {
123 		mp->u.tmem.buf_ptr = 0;
124 		return 0;
125 	}
126 
127 	rc = tee_shm_get_pa(p->u.memref.shm, p->u.memref.shm_offs, &pa);
128 	if (rc)
129 		return rc;
130 
131 	mp->u.tmem.buf_ptr = pa;
132 	mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
133 		    OPTEE_MSG_ATTR_CACHE_SHIFT;
134 
135 	return 0;
136 }
137 
138 static int to_msg_param_reg_mem(struct optee_msg_param *mp,
139 				const struct tee_param *p)
140 {
141 	mp->attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT + p->attr -
142 		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
143 
144 	mp->u.rmem.shm_ref = (unsigned long)p->u.memref.shm;
145 	mp->u.rmem.size = p->u.memref.size;
146 	mp->u.rmem.offs = p->u.memref.shm_offs;
147 	return 0;
148 }
149 
150 /**
151  * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
152  * @msg_params:	OPTEE_MSG parameters
153  * @num_params:	number of elements in the parameter arrays
154  * @params:	subsystem itnernal parameter representation
155  * Returns 0 on success or <0 on failure
156  */
157 int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
158 		       const struct tee_param *params)
159 {
160 	int rc;
161 	size_t n;
162 
163 	for (n = 0; n < num_params; n++) {
164 		const struct tee_param *p = params + n;
165 		struct optee_msg_param *mp = msg_params + n;
166 
167 		switch (p->attr) {
168 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
169 			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
170 			memset(&mp->u, 0, sizeof(mp->u));
171 			break;
172 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
173 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
174 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
175 			mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
176 				   TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
177 			mp->u.value.a = p->u.value.a;
178 			mp->u.value.b = p->u.value.b;
179 			mp->u.value.c = p->u.value.c;
180 			break;
181 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
182 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
183 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
184 			if (tee_shm_is_registered(p->u.memref.shm))
185 				rc = to_msg_param_reg_mem(mp, p);
186 			else
187 				rc = to_msg_param_tmp_mem(mp, p);
188 			if (rc)
189 				return rc;
190 			break;
191 		default:
192 			return -EINVAL;
193 		}
194 	}
195 	return 0;
196 }
197 
198 static void optee_get_version(struct tee_device *teedev,
199 			      struct tee_ioctl_version_data *vers)
200 {
201 	struct tee_ioctl_version_data v = {
202 		.impl_id = TEE_IMPL_ID_OPTEE,
203 		.impl_caps = TEE_OPTEE_CAP_TZ,
204 		.gen_caps = TEE_GEN_CAP_GP,
205 	};
206 	struct optee *optee = tee_get_drvdata(teedev);
207 
208 	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
209 		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
210 	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
211 		v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
212 	*vers = v;
213 }
214 
215 static void optee_bus_scan(struct work_struct *work)
216 {
217 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
218 }
219 
220 static int optee_open(struct tee_context *ctx)
221 {
222 	struct optee_context_data *ctxdata;
223 	struct tee_device *teedev = ctx->teedev;
224 	struct optee *optee = tee_get_drvdata(teedev);
225 
226 	ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
227 	if (!ctxdata)
228 		return -ENOMEM;
229 
230 	if (teedev == optee->supp_teedev) {
231 		bool busy = true;
232 
233 		mutex_lock(&optee->supp.mutex);
234 		if (!optee->supp.ctx) {
235 			busy = false;
236 			optee->supp.ctx = ctx;
237 		}
238 		mutex_unlock(&optee->supp.mutex);
239 		if (busy) {
240 			kfree(ctxdata);
241 			return -EBUSY;
242 		}
243 
244 		if (!optee->scan_bus_done) {
245 			INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
246 			optee->scan_bus_wq = create_workqueue("optee_bus_scan");
247 			if (!optee->scan_bus_wq) {
248 				kfree(ctxdata);
249 				return -ECHILD;
250 			}
251 			queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
252 			optee->scan_bus_done = true;
253 		}
254 	}
255 	mutex_init(&ctxdata->mutex);
256 	INIT_LIST_HEAD(&ctxdata->sess_list);
257 
258 	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
259 		ctx->cap_memref_null  = true;
260 	else
261 		ctx->cap_memref_null = false;
262 
263 	ctx->data = ctxdata;
264 	return 0;
265 }
266 
267 static void optee_release(struct tee_context *ctx)
268 {
269 	struct optee_context_data *ctxdata = ctx->data;
270 	struct tee_device *teedev = ctx->teedev;
271 	struct optee *optee = tee_get_drvdata(teedev);
272 	struct tee_shm *shm;
273 	struct optee_msg_arg *arg = NULL;
274 	phys_addr_t parg;
275 	struct optee_session *sess;
276 	struct optee_session *sess_tmp;
277 
278 	if (!ctxdata)
279 		return;
280 
281 	shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg),
282 			    TEE_SHM_MAPPED | TEE_SHM_PRIV);
283 	if (!IS_ERR(shm)) {
284 		arg = tee_shm_get_va(shm, 0);
285 		/*
286 		 * If va2pa fails for some reason, we can't call into
287 		 * secure world, only free the memory. Secure OS will leak
288 		 * sessions and finally refuse more sessions, but we will
289 		 * at least let normal world reclaim its memory.
290 		 */
291 		if (!IS_ERR(arg))
292 			if (tee_shm_va2pa(shm, arg, &parg))
293 				arg = NULL; /* prevent usage of parg below */
294 	}
295 
296 	list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
297 				 list_node) {
298 		list_del(&sess->list_node);
299 		if (!IS_ERR_OR_NULL(arg)) {
300 			memset(arg, 0, sizeof(*arg));
301 			arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
302 			arg->session = sess->session_id;
303 			optee_do_call_with_arg(ctx, parg);
304 		}
305 		kfree(sess);
306 	}
307 	kfree(ctxdata);
308 
309 	if (!IS_ERR(shm))
310 		tee_shm_free(shm);
311 
312 	ctx->data = NULL;
313 
314 	if (teedev == optee->supp_teedev) {
315 		if (optee->scan_bus_wq) {
316 			destroy_workqueue(optee->scan_bus_wq);
317 			optee->scan_bus_wq = NULL;
318 		}
319 		optee_supp_release(&optee->supp);
320 	}
321 }
322 
323 static const struct tee_driver_ops optee_ops = {
324 	.get_version = optee_get_version,
325 	.open = optee_open,
326 	.release = optee_release,
327 	.open_session = optee_open_session,
328 	.close_session = optee_close_session,
329 	.invoke_func = optee_invoke_func,
330 	.cancel_req = optee_cancel_req,
331 	.shm_register = optee_shm_register,
332 	.shm_unregister = optee_shm_unregister,
333 };
334 
335 static const struct tee_desc optee_desc = {
336 	.name = DRIVER_NAME "-clnt",
337 	.ops = &optee_ops,
338 	.owner = THIS_MODULE,
339 };
340 
341 static const struct tee_driver_ops optee_supp_ops = {
342 	.get_version = optee_get_version,
343 	.open = optee_open,
344 	.release = optee_release,
345 	.supp_recv = optee_supp_recv,
346 	.supp_send = optee_supp_send,
347 	.shm_register = optee_shm_register_supp,
348 	.shm_unregister = optee_shm_unregister_supp,
349 };
350 
351 static const struct tee_desc optee_supp_desc = {
352 	.name = DRIVER_NAME "-supp",
353 	.ops = &optee_supp_ops,
354 	.owner = THIS_MODULE,
355 	.flags = TEE_DESC_PRIVILEGED,
356 };
357 
358 static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
359 {
360 	struct arm_smccc_res res;
361 
362 	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);
363 
364 	if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
365 	    res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
366 		return true;
367 	return false;
368 }
369 
370 static void optee_msg_get_os_revision(optee_invoke_fn *invoke_fn)
371 {
372 	union {
373 		struct arm_smccc_res smccc;
374 		struct optee_smc_call_get_os_revision_result result;
375 	} res = {
376 		.result = {
377 			.build_id = 0
378 		}
379 	};
380 
381 	invoke_fn(OPTEE_SMC_CALL_GET_OS_REVISION, 0, 0, 0, 0, 0, 0, 0,
382 		  &res.smccc);
383 
384 	if (res.result.build_id)
385 		pr_info("revision %lu.%lu (%08lx)", res.result.major,
386 			res.result.minor, res.result.build_id);
387 	else
388 		pr_info("revision %lu.%lu", res.result.major, res.result.minor);
389 }
390 
391 static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
392 {
393 	union {
394 		struct arm_smccc_res smccc;
395 		struct optee_smc_calls_revision_result result;
396 	} res;
397 
398 	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
399 
400 	if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
401 	    (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
402 		return true;
403 	return false;
404 }
405 
406 static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
407 					    u32 *sec_caps)
408 {
409 	union {
410 		struct arm_smccc_res smccc;
411 		struct optee_smc_exchange_capabilities_result result;
412 	} res;
413 	u32 a1 = 0;
414 
415 	/*
416 	 * TODO This isn't enough to tell if it's UP system (from kernel
417 	 * point of view) or not, is_smp() returns the the information
418 	 * needed, but can't be called directly from here.
419 	 */
420 	if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
421 		a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;
422 
423 	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
424 		  &res.smccc);
425 
426 	if (res.result.status != OPTEE_SMC_RETURN_OK)
427 		return false;
428 
429 	*sec_caps = res.result.capabilities;
430 	return true;
431 }
432 
433 static struct tee_shm_pool *optee_config_dyn_shm(void)
434 {
435 	struct tee_shm_pool_mgr *priv_mgr;
436 	struct tee_shm_pool_mgr *dmabuf_mgr;
437 	void *rc;
438 
439 	rc = optee_shm_pool_alloc_pages();
440 	if (IS_ERR(rc))
441 		return rc;
442 	priv_mgr = rc;
443 
444 	rc = optee_shm_pool_alloc_pages();
445 	if (IS_ERR(rc)) {
446 		tee_shm_pool_mgr_destroy(priv_mgr);
447 		return rc;
448 	}
449 	dmabuf_mgr = rc;
450 
451 	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
452 	if (IS_ERR(rc)) {
453 		tee_shm_pool_mgr_destroy(priv_mgr);
454 		tee_shm_pool_mgr_destroy(dmabuf_mgr);
455 	}
456 
457 	return rc;
458 }
459 
460 static struct tee_shm_pool *
461 optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
462 {
463 	union {
464 		struct arm_smccc_res smccc;
465 		struct optee_smc_get_shm_config_result result;
466 	} res;
467 	unsigned long vaddr;
468 	phys_addr_t paddr;
469 	size_t size;
470 	phys_addr_t begin;
471 	phys_addr_t end;
472 	void *va;
473 	struct tee_shm_pool_mgr *priv_mgr;
474 	struct tee_shm_pool_mgr *dmabuf_mgr;
475 	void *rc;
476 	const int sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
477 
478 	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
479 	if (res.result.status != OPTEE_SMC_RETURN_OK) {
480 		pr_err("static shm service not available\n");
481 		return ERR_PTR(-ENOENT);
482 	}
483 
484 	if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
485 		pr_err("only normal cached shared memory supported\n");
486 		return ERR_PTR(-EINVAL);
487 	}
488 
489 	begin = roundup(res.result.start, PAGE_SIZE);
490 	end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
491 	paddr = begin;
492 	size = end - begin;
493 
494 	if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
495 		pr_err("too small shared memory area\n");
496 		return ERR_PTR(-EINVAL);
497 	}
498 
499 	va = memremap(paddr, size, MEMREMAP_WB);
500 	if (!va) {
501 		pr_err("shared memory ioremap failed\n");
502 		return ERR_PTR(-EINVAL);
503 	}
504 	vaddr = (unsigned long)va;
505 
506 	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, sz,
507 					    3 /* 8 bytes aligned */);
508 	if (IS_ERR(rc))
509 		goto err_memunmap;
510 	priv_mgr = rc;
511 
512 	vaddr += sz;
513 	paddr += sz;
514 	size -= sz;
515 
516 	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, size, PAGE_SHIFT);
517 	if (IS_ERR(rc))
518 		goto err_free_priv_mgr;
519 	dmabuf_mgr = rc;
520 
521 	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
522 	if (IS_ERR(rc))
523 		goto err_free_dmabuf_mgr;
524 
525 	*memremaped_shm = va;
526 
527 	return rc;
528 
529 err_free_dmabuf_mgr:
530 	tee_shm_pool_mgr_destroy(dmabuf_mgr);
531 err_free_priv_mgr:
532 	tee_shm_pool_mgr_destroy(priv_mgr);
533 err_memunmap:
534 	memunmap(va);
535 	return rc;
536 }
537 
538 /* Simple wrapper functions to be able to use a function pointer */
539 static void optee_smccc_smc(unsigned long a0, unsigned long a1,
540 			    unsigned long a2, unsigned long a3,
541 			    unsigned long a4, unsigned long a5,
542 			    unsigned long a6, unsigned long a7,
543 			    struct arm_smccc_res *res)
544 {
545 	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
546 }
547 
548 static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
549 			    unsigned long a2, unsigned long a3,
550 			    unsigned long a4, unsigned long a5,
551 			    unsigned long a6, unsigned long a7,
552 			    struct arm_smccc_res *res)
553 {
554 	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
555 }
556 
557 static optee_invoke_fn *get_invoke_func(struct device *dev)
558 {
559 	const char *method;
560 
561 	pr_info("probing for conduit method.\n");
562 
563 	if (device_property_read_string(dev, "method", &method)) {
564 		pr_warn("missing \"method\" property\n");
565 		return ERR_PTR(-ENXIO);
566 	}
567 
568 	if (!strcmp("hvc", method))
569 		return optee_smccc_hvc;
570 	else if (!strcmp("smc", method))
571 		return optee_smccc_smc;
572 
573 	pr_warn("invalid \"method\" property: %s\n", method);
574 	return ERR_PTR(-EINVAL);
575 }
576 
577 /* optee_remove - Device Removal Routine
578  * @pdev: platform device information struct
579  *
580  * optee_remove is called by platform subsystem to alert the driver
581  * that it should release the device
582  */
583 
584 static int optee_remove(struct platform_device *pdev)
585 {
586 	struct optee *optee = platform_get_drvdata(pdev);
587 
588 	/*
589 	 * Ask OP-TEE to free all cached shared memory objects to decrease
590 	 * reference counters and also avoid wild pointers in secure world
591 	 * into the old shared memory range.
592 	 */
593 	optee_disable_shm_cache(optee);
594 
595 	/*
596 	 * The two devices have to be unregistered before we can free the
597 	 * other resources.
598 	 */
599 	tee_device_unregister(optee->supp_teedev);
600 	tee_device_unregister(optee->teedev);
601 
602 	tee_shm_pool_free(optee->pool);
603 	if (optee->memremaped_shm)
604 		memunmap(optee->memremaped_shm);
605 	optee_wait_queue_exit(&optee->wait_queue);
606 	optee_supp_uninit(&optee->supp);
607 	mutex_destroy(&optee->call_queue.mutex);
608 
609 	kfree(optee);
610 
611 	return 0;
612 }
613 
614 /* optee_shutdown - Device Removal Routine
615  * @pdev: platform device information struct
616  *
617  * platform_shutdown is called by the platform subsystem to alert
618  * the driver that a shutdown, reboot, or kexec is happening and
619  * device must be disabled.
620  */
621 static void optee_shutdown(struct platform_device *pdev)
622 {
623 	optee_disable_shm_cache(platform_get_drvdata(pdev));
624 }
625 
626 static int optee_probe(struct platform_device *pdev)
627 {
628 	optee_invoke_fn *invoke_fn;
629 	struct tee_shm_pool *pool = ERR_PTR(-EINVAL);
630 	struct optee *optee = NULL;
631 	void *memremaped_shm = NULL;
632 	struct tee_device *teedev;
633 	u32 sec_caps;
634 	int rc;
635 
636 	/*
637 	 * The kernel may have crashed at the same time that all available
638 	 * secure world threads were suspended and we cannot reschedule the
639 	 * suspended threads without access to the crashed kernel's wait_queue.
640 	 * Therefore, we cannot reliably initialize the OP-TEE driver in the
641 	 * kdump kernel.
642 	 */
643 	if (is_kdump_kernel())
644 		return -ENODEV;
645 
646 	invoke_fn = get_invoke_func(&pdev->dev);
647 	if (IS_ERR(invoke_fn))
648 		return PTR_ERR(invoke_fn);
649 
650 	if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
651 		pr_warn("api uid mismatch\n");
652 		return -EINVAL;
653 	}
654 
655 	optee_msg_get_os_revision(invoke_fn);
656 
657 	if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
658 		pr_warn("api revision mismatch\n");
659 		return -EINVAL;
660 	}
661 
662 	if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) {
663 		pr_warn("capabilities mismatch\n");
664 		return -EINVAL;
665 	}
666 
667 	/*
668 	 * Try to use dynamic shared memory if possible
669 	 */
670 	if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
671 		pool = optee_config_dyn_shm();
672 
673 	/*
674 	 * If dynamic shared memory is not available or failed - try static one
675 	 */
676 	if (IS_ERR(pool) && (sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
677 		pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
678 
679 	if (IS_ERR(pool))
680 		return PTR_ERR(pool);
681 
682 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
683 	if (!optee) {
684 		rc = -ENOMEM;
685 		goto err;
686 	}
687 
688 	optee->invoke_fn = invoke_fn;
689 	optee->sec_caps = sec_caps;
690 
691 	teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
692 	if (IS_ERR(teedev)) {
693 		rc = PTR_ERR(teedev);
694 		goto err;
695 	}
696 	optee->teedev = teedev;
697 
698 	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
699 	if (IS_ERR(teedev)) {
700 		rc = PTR_ERR(teedev);
701 		goto err;
702 	}
703 	optee->supp_teedev = teedev;
704 
705 	rc = tee_device_register(optee->teedev);
706 	if (rc)
707 		goto err;
708 
709 	rc = tee_device_register(optee->supp_teedev);
710 	if (rc)
711 		goto err;
712 
713 	mutex_init(&optee->call_queue.mutex);
714 	INIT_LIST_HEAD(&optee->call_queue.waiters);
715 	optee_wait_queue_init(&optee->wait_queue);
716 	optee_supp_init(&optee->supp);
717 	optee->memremaped_shm = memremaped_shm;
718 	optee->pool = pool;
719 
720 	/*
721 	 * Ensure that there are no pre-existing shm objects before enabling
722 	 * the shm cache so that there's no chance of receiving an invalid
723 	 * address during shutdown. This could occur, for example, if we're
724 	 * kexec booting from an older kernel that did not properly cleanup the
725 	 * shm cache.
726 	 */
727 	optee_disable_unmapped_shm_cache(optee);
728 
729 	optee_enable_shm_cache(optee);
730 
731 	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
732 		pr_info("dynamic shared memory is enabled\n");
733 
734 	platform_set_drvdata(pdev, optee);
735 
736 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
737 	if (rc) {
738 		optee_remove(pdev);
739 		return rc;
740 	}
741 
742 	pr_info("initialized driver\n");
743 	return 0;
744 err:
745 	if (optee) {
746 		/*
747 		 * tee_device_unregister() is safe to call even if the
748 		 * devices hasn't been registered with
749 		 * tee_device_register() yet.
750 		 */
751 		tee_device_unregister(optee->supp_teedev);
752 		tee_device_unregister(optee->teedev);
753 		kfree(optee);
754 	}
755 	if (pool)
756 		tee_shm_pool_free(pool);
757 	if (memremaped_shm)
758 		memunmap(memremaped_shm);
759 	return rc;
760 }
761 
762 static const struct of_device_id optee_dt_match[] = {
763 	{ .compatible = "linaro,optee-tz" },
764 	{},
765 };
766 MODULE_DEVICE_TABLE(of, optee_dt_match);
767 
768 static struct platform_driver optee_driver = {
769 	.probe  = optee_probe,
770 	.remove = optee_remove,
771 	.shutdown = optee_shutdown,
772 	.driver = {
773 		.name = "optee",
774 		.of_match_table = optee_dt_match,
775 	},
776 };
777 module_platform_driver(optee_driver);
778 
779 MODULE_AUTHOR("Linaro");
780 MODULE_DESCRIPTION("OP-TEE driver");
781 MODULE_VERSION("1.0");
782 MODULE_LICENSE("GPL v2");
783 MODULE_ALIAS("platform:optee");
784