xref: /openbmc/linux/drivers/tee/tee_core.c (revision ba61bb17)
1 /*
2  * Copyright (c) 2015-2016, 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) "%s: " fmt, __func__
16 
17 #include <linux/cdev.h>
18 #include <linux/device.h>
19 #include <linux/fs.h>
20 #include <linux/idr.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/tee_drv.h>
24 #include <linux/uaccess.h>
25 #include "tee_private.h"
26 
27 #define TEE_NUM_DEVICES	32
28 
29 #define TEE_IOCTL_PARAM_SIZE(x) (sizeof(struct tee_param) * (x))
30 
31 /*
32  * Unprivileged devices in the lower half range and privileged devices in
33  * the upper half range.
34  */
35 static DECLARE_BITMAP(dev_mask, TEE_NUM_DEVICES);
36 static DEFINE_SPINLOCK(driver_lock);
37 
38 static struct class *tee_class;
39 static dev_t tee_devt;
40 
41 static int tee_open(struct inode *inode, struct file *filp)
42 {
43 	int rc;
44 	struct tee_device *teedev;
45 	struct tee_context *ctx;
46 
47 	teedev = container_of(inode->i_cdev, struct tee_device, cdev);
48 	if (!tee_device_get(teedev))
49 		return -EINVAL;
50 
51 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
52 	if (!ctx) {
53 		rc = -ENOMEM;
54 		goto err;
55 	}
56 
57 	kref_init(&ctx->refcount);
58 	ctx->teedev = teedev;
59 	INIT_LIST_HEAD(&ctx->list_shm);
60 	filp->private_data = ctx;
61 	rc = teedev->desc->ops->open(ctx);
62 	if (rc)
63 		goto err;
64 
65 	return 0;
66 err:
67 	kfree(ctx);
68 	tee_device_put(teedev);
69 	return rc;
70 }
71 
72 void teedev_ctx_get(struct tee_context *ctx)
73 {
74 	if (ctx->releasing)
75 		return;
76 
77 	kref_get(&ctx->refcount);
78 }
79 
80 static void teedev_ctx_release(struct kref *ref)
81 {
82 	struct tee_context *ctx = container_of(ref, struct tee_context,
83 					       refcount);
84 	ctx->releasing = true;
85 	ctx->teedev->desc->ops->release(ctx);
86 	kfree(ctx);
87 }
88 
89 void teedev_ctx_put(struct tee_context *ctx)
90 {
91 	if (ctx->releasing)
92 		return;
93 
94 	kref_put(&ctx->refcount, teedev_ctx_release);
95 }
96 
97 static void teedev_close_context(struct tee_context *ctx)
98 {
99 	tee_device_put(ctx->teedev);
100 	teedev_ctx_put(ctx);
101 }
102 
103 static int tee_release(struct inode *inode, struct file *filp)
104 {
105 	teedev_close_context(filp->private_data);
106 	return 0;
107 }
108 
109 static int tee_ioctl_version(struct tee_context *ctx,
110 			     struct tee_ioctl_version_data __user *uvers)
111 {
112 	struct tee_ioctl_version_data vers;
113 
114 	ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
115 
116 	if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
117 		vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
118 
119 	if (copy_to_user(uvers, &vers, sizeof(vers)))
120 		return -EFAULT;
121 
122 	return 0;
123 }
124 
125 static int tee_ioctl_shm_alloc(struct tee_context *ctx,
126 			       struct tee_ioctl_shm_alloc_data __user *udata)
127 {
128 	long ret;
129 	struct tee_ioctl_shm_alloc_data data;
130 	struct tee_shm *shm;
131 
132 	if (copy_from_user(&data, udata, sizeof(data)))
133 		return -EFAULT;
134 
135 	/* Currently no input flags are supported */
136 	if (data.flags)
137 		return -EINVAL;
138 
139 	shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
140 	if (IS_ERR(shm))
141 		return PTR_ERR(shm);
142 
143 	data.id = shm->id;
144 	data.flags = shm->flags;
145 	data.size = shm->size;
146 
147 	if (copy_to_user(udata, &data, sizeof(data)))
148 		ret = -EFAULT;
149 	else
150 		ret = tee_shm_get_fd(shm);
151 
152 	/*
153 	 * When user space closes the file descriptor the shared memory
154 	 * should be freed or if tee_shm_get_fd() failed then it will
155 	 * be freed immediately.
156 	 */
157 	tee_shm_put(shm);
158 	return ret;
159 }
160 
161 static int
162 tee_ioctl_shm_register(struct tee_context *ctx,
163 		       struct tee_ioctl_shm_register_data __user *udata)
164 {
165 	long ret;
166 	struct tee_ioctl_shm_register_data data;
167 	struct tee_shm *shm;
168 
169 	if (copy_from_user(&data, udata, sizeof(data)))
170 		return -EFAULT;
171 
172 	/* Currently no input flags are supported */
173 	if (data.flags)
174 		return -EINVAL;
175 
176 	shm = tee_shm_register(ctx, data.addr, data.length,
177 			       TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
178 	if (IS_ERR(shm))
179 		return PTR_ERR(shm);
180 
181 	data.id = shm->id;
182 	data.flags = shm->flags;
183 	data.length = shm->size;
184 
185 	if (copy_to_user(udata, &data, sizeof(data)))
186 		ret = -EFAULT;
187 	else
188 		ret = tee_shm_get_fd(shm);
189 	/*
190 	 * When user space closes the file descriptor the shared memory
191 	 * should be freed or if tee_shm_get_fd() failed then it will
192 	 * be freed immediately.
193 	 */
194 	tee_shm_put(shm);
195 	return ret;
196 }
197 
198 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
199 			    size_t num_params,
200 			    struct tee_ioctl_param __user *uparams)
201 {
202 	size_t n;
203 
204 	for (n = 0; n < num_params; n++) {
205 		struct tee_shm *shm;
206 		struct tee_ioctl_param ip;
207 
208 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
209 			return -EFAULT;
210 
211 		/* All unused attribute bits has to be zero */
212 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
213 			return -EINVAL;
214 
215 		params[n].attr = ip.attr;
216 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
217 		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
218 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
219 			break;
220 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
221 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
222 			params[n].u.value.a = ip.a;
223 			params[n].u.value.b = ip.b;
224 			params[n].u.value.c = ip.c;
225 			break;
226 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
227 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
228 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
229 			/*
230 			 * If we fail to get a pointer to a shared memory
231 			 * object (and increase the ref count) from an
232 			 * identifier we return an error. All pointers that
233 			 * has been added in params have an increased ref
234 			 * count. It's the callers responibility to do
235 			 * tee_shm_put() on all resolved pointers.
236 			 */
237 			shm = tee_shm_get_from_id(ctx, ip.c);
238 			if (IS_ERR(shm))
239 				return PTR_ERR(shm);
240 
241 			/*
242 			 * Ensure offset + size does not overflow offset
243 			 * and does not overflow the size of the referred
244 			 * shared memory object.
245 			 */
246 			if ((ip.a + ip.b) < ip.a ||
247 			    (ip.a + ip.b) > shm->size) {
248 				tee_shm_put(shm);
249 				return -EINVAL;
250 			}
251 
252 			params[n].u.memref.shm_offs = ip.a;
253 			params[n].u.memref.size = ip.b;
254 			params[n].u.memref.shm = shm;
255 			break;
256 		default:
257 			/* Unknown attribute */
258 			return -EINVAL;
259 		}
260 	}
261 	return 0;
262 }
263 
264 static int params_to_user(struct tee_ioctl_param __user *uparams,
265 			  size_t num_params, struct tee_param *params)
266 {
267 	size_t n;
268 
269 	for (n = 0; n < num_params; n++) {
270 		struct tee_ioctl_param __user *up = uparams + n;
271 		struct tee_param *p = params + n;
272 
273 		switch (p->attr) {
274 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
275 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
276 			if (put_user(p->u.value.a, &up->a) ||
277 			    put_user(p->u.value.b, &up->b) ||
278 			    put_user(p->u.value.c, &up->c))
279 				return -EFAULT;
280 			break;
281 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
282 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
283 			if (put_user((u64)p->u.memref.size, &up->b))
284 				return -EFAULT;
285 		default:
286 			break;
287 		}
288 	}
289 	return 0;
290 }
291 
292 static int tee_ioctl_open_session(struct tee_context *ctx,
293 				  struct tee_ioctl_buf_data __user *ubuf)
294 {
295 	int rc;
296 	size_t n;
297 	struct tee_ioctl_buf_data buf;
298 	struct tee_ioctl_open_session_arg __user *uarg;
299 	struct tee_ioctl_open_session_arg arg;
300 	struct tee_ioctl_param __user *uparams = NULL;
301 	struct tee_param *params = NULL;
302 	bool have_session = false;
303 
304 	if (!ctx->teedev->desc->ops->open_session)
305 		return -EINVAL;
306 
307 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
308 		return -EFAULT;
309 
310 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
311 	    buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
312 		return -EINVAL;
313 
314 	uarg = u64_to_user_ptr(buf.buf_ptr);
315 	if (copy_from_user(&arg, uarg, sizeof(arg)))
316 		return -EFAULT;
317 
318 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
319 		return -EINVAL;
320 
321 	if (arg.num_params) {
322 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
323 				 GFP_KERNEL);
324 		if (!params)
325 			return -ENOMEM;
326 		uparams = uarg->params;
327 		rc = params_from_user(ctx, params, arg.num_params, uparams);
328 		if (rc)
329 			goto out;
330 	}
331 
332 	rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
333 	if (rc)
334 		goto out;
335 	have_session = true;
336 
337 	if (put_user(arg.session, &uarg->session) ||
338 	    put_user(arg.ret, &uarg->ret) ||
339 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
340 		rc = -EFAULT;
341 		goto out;
342 	}
343 	rc = params_to_user(uparams, arg.num_params, params);
344 out:
345 	/*
346 	 * If we've succeeded to open the session but failed to communicate
347 	 * it back to user space, close the session again to avoid leakage.
348 	 */
349 	if (rc && have_session && ctx->teedev->desc->ops->close_session)
350 		ctx->teedev->desc->ops->close_session(ctx, arg.session);
351 
352 	if (params) {
353 		/* Decrease ref count for all valid shared memory pointers */
354 		for (n = 0; n < arg.num_params; n++)
355 			if (tee_param_is_memref(params + n) &&
356 			    params[n].u.memref.shm)
357 				tee_shm_put(params[n].u.memref.shm);
358 		kfree(params);
359 	}
360 
361 	return rc;
362 }
363 
364 static int tee_ioctl_invoke(struct tee_context *ctx,
365 			    struct tee_ioctl_buf_data __user *ubuf)
366 {
367 	int rc;
368 	size_t n;
369 	struct tee_ioctl_buf_data buf;
370 	struct tee_ioctl_invoke_arg __user *uarg;
371 	struct tee_ioctl_invoke_arg arg;
372 	struct tee_ioctl_param __user *uparams = NULL;
373 	struct tee_param *params = NULL;
374 
375 	if (!ctx->teedev->desc->ops->invoke_func)
376 		return -EINVAL;
377 
378 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
379 		return -EFAULT;
380 
381 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
382 	    buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
383 		return -EINVAL;
384 
385 	uarg = u64_to_user_ptr(buf.buf_ptr);
386 	if (copy_from_user(&arg, uarg, sizeof(arg)))
387 		return -EFAULT;
388 
389 	if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
390 		return -EINVAL;
391 
392 	if (arg.num_params) {
393 		params = kcalloc(arg.num_params, sizeof(struct tee_param),
394 				 GFP_KERNEL);
395 		if (!params)
396 			return -ENOMEM;
397 		uparams = uarg->params;
398 		rc = params_from_user(ctx, params, arg.num_params, uparams);
399 		if (rc)
400 			goto out;
401 	}
402 
403 	rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
404 	if (rc)
405 		goto out;
406 
407 	if (put_user(arg.ret, &uarg->ret) ||
408 	    put_user(arg.ret_origin, &uarg->ret_origin)) {
409 		rc = -EFAULT;
410 		goto out;
411 	}
412 	rc = params_to_user(uparams, arg.num_params, params);
413 out:
414 	if (params) {
415 		/* Decrease ref count for all valid shared memory pointers */
416 		for (n = 0; n < arg.num_params; n++)
417 			if (tee_param_is_memref(params + n) &&
418 			    params[n].u.memref.shm)
419 				tee_shm_put(params[n].u.memref.shm);
420 		kfree(params);
421 	}
422 	return rc;
423 }
424 
425 static int tee_ioctl_cancel(struct tee_context *ctx,
426 			    struct tee_ioctl_cancel_arg __user *uarg)
427 {
428 	struct tee_ioctl_cancel_arg arg;
429 
430 	if (!ctx->teedev->desc->ops->cancel_req)
431 		return -EINVAL;
432 
433 	if (copy_from_user(&arg, uarg, sizeof(arg)))
434 		return -EFAULT;
435 
436 	return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
437 						  arg.session);
438 }
439 
440 static int
441 tee_ioctl_close_session(struct tee_context *ctx,
442 			struct tee_ioctl_close_session_arg __user *uarg)
443 {
444 	struct tee_ioctl_close_session_arg arg;
445 
446 	if (!ctx->teedev->desc->ops->close_session)
447 		return -EINVAL;
448 
449 	if (copy_from_user(&arg, uarg, sizeof(arg)))
450 		return -EFAULT;
451 
452 	return ctx->teedev->desc->ops->close_session(ctx, arg.session);
453 }
454 
455 static int params_to_supp(struct tee_context *ctx,
456 			  struct tee_ioctl_param __user *uparams,
457 			  size_t num_params, struct tee_param *params)
458 {
459 	size_t n;
460 
461 	for (n = 0; n < num_params; n++) {
462 		struct tee_ioctl_param ip;
463 		struct tee_param *p = params + n;
464 
465 		ip.attr = p->attr;
466 		switch (p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
467 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
468 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
469 			ip.a = p->u.value.a;
470 			ip.b = p->u.value.b;
471 			ip.c = p->u.value.c;
472 			break;
473 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
474 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
475 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
476 			ip.b = p->u.memref.size;
477 			if (!p->u.memref.shm) {
478 				ip.a = 0;
479 				ip.c = (u64)-1; /* invalid shm id */
480 				break;
481 			}
482 			ip.a = p->u.memref.shm_offs;
483 			ip.c = p->u.memref.shm->id;
484 			break;
485 		default:
486 			ip.a = 0;
487 			ip.b = 0;
488 			ip.c = 0;
489 			break;
490 		}
491 
492 		if (copy_to_user(uparams + n, &ip, sizeof(ip)))
493 			return -EFAULT;
494 	}
495 
496 	return 0;
497 }
498 
499 static int tee_ioctl_supp_recv(struct tee_context *ctx,
500 			       struct tee_ioctl_buf_data __user *ubuf)
501 {
502 	int rc;
503 	struct tee_ioctl_buf_data buf;
504 	struct tee_iocl_supp_recv_arg __user *uarg;
505 	struct tee_param *params;
506 	u32 num_params;
507 	u32 func;
508 
509 	if (!ctx->teedev->desc->ops->supp_recv)
510 		return -EINVAL;
511 
512 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
513 		return -EFAULT;
514 
515 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
516 	    buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
517 		return -EINVAL;
518 
519 	uarg = u64_to_user_ptr(buf.buf_ptr);
520 	if (get_user(num_params, &uarg->num_params))
521 		return -EFAULT;
522 
523 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
524 		return -EINVAL;
525 
526 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
527 	if (!params)
528 		return -ENOMEM;
529 
530 	rc = params_from_user(ctx, params, num_params, uarg->params);
531 	if (rc)
532 		goto out;
533 
534 	rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
535 	if (rc)
536 		goto out;
537 
538 	if (put_user(func, &uarg->func) ||
539 	    put_user(num_params, &uarg->num_params)) {
540 		rc = -EFAULT;
541 		goto out;
542 	}
543 
544 	rc = params_to_supp(ctx, uarg->params, num_params, params);
545 out:
546 	kfree(params);
547 	return rc;
548 }
549 
550 static int params_from_supp(struct tee_param *params, size_t num_params,
551 			    struct tee_ioctl_param __user *uparams)
552 {
553 	size_t n;
554 
555 	for (n = 0; n < num_params; n++) {
556 		struct tee_param *p = params + n;
557 		struct tee_ioctl_param ip;
558 
559 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
560 			return -EFAULT;
561 
562 		/* All unused attribute bits has to be zero */
563 		if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_MASK)
564 			return -EINVAL;
565 
566 		p->attr = ip.attr;
567 		switch (ip.attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
568 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
569 		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
570 			/* Only out and in/out values can be updated */
571 			p->u.value.a = ip.a;
572 			p->u.value.b = ip.b;
573 			p->u.value.c = ip.c;
574 			break;
575 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
576 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
577 			/*
578 			 * Only the size of the memref can be updated.
579 			 * Since we don't have access to the original
580 			 * parameters here, only store the supplied size.
581 			 * The driver will copy the updated size into the
582 			 * original parameters.
583 			 */
584 			p->u.memref.shm = NULL;
585 			p->u.memref.shm_offs = 0;
586 			p->u.memref.size = ip.b;
587 			break;
588 		default:
589 			memset(&p->u, 0, sizeof(p->u));
590 			break;
591 		}
592 	}
593 	return 0;
594 }
595 
596 static int tee_ioctl_supp_send(struct tee_context *ctx,
597 			       struct tee_ioctl_buf_data __user *ubuf)
598 {
599 	long rc;
600 	struct tee_ioctl_buf_data buf;
601 	struct tee_iocl_supp_send_arg __user *uarg;
602 	struct tee_param *params;
603 	u32 num_params;
604 	u32 ret;
605 
606 	/* Not valid for this driver */
607 	if (!ctx->teedev->desc->ops->supp_send)
608 		return -EINVAL;
609 
610 	if (copy_from_user(&buf, ubuf, sizeof(buf)))
611 		return -EFAULT;
612 
613 	if (buf.buf_len > TEE_MAX_ARG_SIZE ||
614 	    buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
615 		return -EINVAL;
616 
617 	uarg = u64_to_user_ptr(buf.buf_ptr);
618 	if (get_user(ret, &uarg->ret) ||
619 	    get_user(num_params, &uarg->num_params))
620 		return -EFAULT;
621 
622 	if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
623 		return -EINVAL;
624 
625 	params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
626 	if (!params)
627 		return -ENOMEM;
628 
629 	rc = params_from_supp(params, num_params, uarg->params);
630 	if (rc)
631 		goto out;
632 
633 	rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
634 out:
635 	kfree(params);
636 	return rc;
637 }
638 
639 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
640 {
641 	struct tee_context *ctx = filp->private_data;
642 	void __user *uarg = (void __user *)arg;
643 
644 	switch (cmd) {
645 	case TEE_IOC_VERSION:
646 		return tee_ioctl_version(ctx, uarg);
647 	case TEE_IOC_SHM_ALLOC:
648 		return tee_ioctl_shm_alloc(ctx, uarg);
649 	case TEE_IOC_SHM_REGISTER:
650 		return tee_ioctl_shm_register(ctx, uarg);
651 	case TEE_IOC_OPEN_SESSION:
652 		return tee_ioctl_open_session(ctx, uarg);
653 	case TEE_IOC_INVOKE:
654 		return tee_ioctl_invoke(ctx, uarg);
655 	case TEE_IOC_CANCEL:
656 		return tee_ioctl_cancel(ctx, uarg);
657 	case TEE_IOC_CLOSE_SESSION:
658 		return tee_ioctl_close_session(ctx, uarg);
659 	case TEE_IOC_SUPPL_RECV:
660 		return tee_ioctl_supp_recv(ctx, uarg);
661 	case TEE_IOC_SUPPL_SEND:
662 		return tee_ioctl_supp_send(ctx, uarg);
663 	default:
664 		return -EINVAL;
665 	}
666 }
667 
668 static const struct file_operations tee_fops = {
669 	.owner = THIS_MODULE,
670 	.open = tee_open,
671 	.release = tee_release,
672 	.unlocked_ioctl = tee_ioctl,
673 	.compat_ioctl = tee_ioctl,
674 };
675 
676 static void tee_release_device(struct device *dev)
677 {
678 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
679 
680 	spin_lock(&driver_lock);
681 	clear_bit(teedev->id, dev_mask);
682 	spin_unlock(&driver_lock);
683 	mutex_destroy(&teedev->mutex);
684 	idr_destroy(&teedev->idr);
685 	kfree(teedev);
686 }
687 
688 /**
689  * tee_device_alloc() - Allocate a new struct tee_device instance
690  * @teedesc:	Descriptor for this driver
691  * @dev:	Parent device for this device
692  * @pool:	Shared memory pool, NULL if not used
693  * @driver_data: Private driver data for this device
694  *
695  * Allocates a new struct tee_device instance. The device is
696  * removed by tee_device_unregister().
697  *
698  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
699  */
700 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
701 				    struct device *dev,
702 				    struct tee_shm_pool *pool,
703 				    void *driver_data)
704 {
705 	struct tee_device *teedev;
706 	void *ret;
707 	int rc, max_id;
708 	int offs = 0;
709 
710 	if (!teedesc || !teedesc->name || !teedesc->ops ||
711 	    !teedesc->ops->get_version || !teedesc->ops->open ||
712 	    !teedesc->ops->release || !pool)
713 		return ERR_PTR(-EINVAL);
714 
715 	teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
716 	if (!teedev) {
717 		ret = ERR_PTR(-ENOMEM);
718 		goto err;
719 	}
720 
721 	max_id = TEE_NUM_DEVICES / 2;
722 
723 	if (teedesc->flags & TEE_DESC_PRIVILEGED) {
724 		offs = TEE_NUM_DEVICES / 2;
725 		max_id = TEE_NUM_DEVICES;
726 	}
727 
728 	spin_lock(&driver_lock);
729 	teedev->id = find_next_zero_bit(dev_mask, max_id, offs);
730 	if (teedev->id < max_id)
731 		set_bit(teedev->id, dev_mask);
732 	spin_unlock(&driver_lock);
733 
734 	if (teedev->id >= max_id) {
735 		ret = ERR_PTR(-ENOMEM);
736 		goto err;
737 	}
738 
739 	snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
740 		 teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
741 		 teedev->id - offs);
742 
743 	teedev->dev.class = tee_class;
744 	teedev->dev.release = tee_release_device;
745 	teedev->dev.parent = dev;
746 
747 	teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
748 
749 	rc = dev_set_name(&teedev->dev, "%s", teedev->name);
750 	if (rc) {
751 		ret = ERR_PTR(rc);
752 		goto err_devt;
753 	}
754 
755 	cdev_init(&teedev->cdev, &tee_fops);
756 	teedev->cdev.owner = teedesc->owner;
757 	teedev->cdev.kobj.parent = &teedev->dev.kobj;
758 
759 	dev_set_drvdata(&teedev->dev, driver_data);
760 	device_initialize(&teedev->dev);
761 
762 	/* 1 as tee_device_unregister() does one final tee_device_put() */
763 	teedev->num_users = 1;
764 	init_completion(&teedev->c_no_users);
765 	mutex_init(&teedev->mutex);
766 	idr_init(&teedev->idr);
767 
768 	teedev->desc = teedesc;
769 	teedev->pool = pool;
770 
771 	return teedev;
772 err_devt:
773 	unregister_chrdev_region(teedev->dev.devt, 1);
774 err:
775 	pr_err("could not register %s driver\n",
776 	       teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
777 	if (teedev && teedev->id < TEE_NUM_DEVICES) {
778 		spin_lock(&driver_lock);
779 		clear_bit(teedev->id, dev_mask);
780 		spin_unlock(&driver_lock);
781 	}
782 	kfree(teedev);
783 	return ret;
784 }
785 EXPORT_SYMBOL_GPL(tee_device_alloc);
786 
787 static ssize_t implementation_id_show(struct device *dev,
788 				      struct device_attribute *attr, char *buf)
789 {
790 	struct tee_device *teedev = container_of(dev, struct tee_device, dev);
791 	struct tee_ioctl_version_data vers;
792 
793 	teedev->desc->ops->get_version(teedev, &vers);
794 	return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
795 }
796 static DEVICE_ATTR_RO(implementation_id);
797 
798 static struct attribute *tee_dev_attrs[] = {
799 	&dev_attr_implementation_id.attr,
800 	NULL
801 };
802 
803 static const struct attribute_group tee_dev_group = {
804 	.attrs = tee_dev_attrs,
805 };
806 
807 /**
808  * tee_device_register() - Registers a TEE device
809  * @teedev:	Device to register
810  *
811  * tee_device_unregister() need to be called to remove the @teedev if
812  * this function fails.
813  *
814  * @returns < 0 on failure
815  */
816 int tee_device_register(struct tee_device *teedev)
817 {
818 	int rc;
819 
820 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
821 		dev_err(&teedev->dev, "attempt to register twice\n");
822 		return -EINVAL;
823 	}
824 
825 	rc = cdev_add(&teedev->cdev, teedev->dev.devt, 1);
826 	if (rc) {
827 		dev_err(&teedev->dev,
828 			"unable to cdev_add() %s, major %d, minor %d, err=%d\n",
829 			teedev->name, MAJOR(teedev->dev.devt),
830 			MINOR(teedev->dev.devt), rc);
831 		return rc;
832 	}
833 
834 	rc = device_add(&teedev->dev);
835 	if (rc) {
836 		dev_err(&teedev->dev,
837 			"unable to device_add() %s, major %d, minor %d, err=%d\n",
838 			teedev->name, MAJOR(teedev->dev.devt),
839 			MINOR(teedev->dev.devt), rc);
840 		goto err_device_add;
841 	}
842 
843 	rc = sysfs_create_group(&teedev->dev.kobj, &tee_dev_group);
844 	if (rc) {
845 		dev_err(&teedev->dev,
846 			"failed to create sysfs attributes, err=%d\n", rc);
847 		goto err_sysfs_create_group;
848 	}
849 
850 	teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
851 	return 0;
852 
853 err_sysfs_create_group:
854 	device_del(&teedev->dev);
855 err_device_add:
856 	cdev_del(&teedev->cdev);
857 	return rc;
858 }
859 EXPORT_SYMBOL_GPL(tee_device_register);
860 
861 void tee_device_put(struct tee_device *teedev)
862 {
863 	mutex_lock(&teedev->mutex);
864 	/* Shouldn't put in this state */
865 	if (!WARN_ON(!teedev->desc)) {
866 		teedev->num_users--;
867 		if (!teedev->num_users) {
868 			teedev->desc = NULL;
869 			complete(&teedev->c_no_users);
870 		}
871 	}
872 	mutex_unlock(&teedev->mutex);
873 }
874 
875 bool tee_device_get(struct tee_device *teedev)
876 {
877 	mutex_lock(&teedev->mutex);
878 	if (!teedev->desc) {
879 		mutex_unlock(&teedev->mutex);
880 		return false;
881 	}
882 	teedev->num_users++;
883 	mutex_unlock(&teedev->mutex);
884 	return true;
885 }
886 
887 /**
888  * tee_device_unregister() - Removes a TEE device
889  * @teedev:	Device to unregister
890  *
891  * This function should be called to remove the @teedev even if
892  * tee_device_register() hasn't been called yet. Does nothing if
893  * @teedev is NULL.
894  */
895 void tee_device_unregister(struct tee_device *teedev)
896 {
897 	if (!teedev)
898 		return;
899 
900 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
901 		sysfs_remove_group(&teedev->dev.kobj, &tee_dev_group);
902 		cdev_del(&teedev->cdev);
903 		device_del(&teedev->dev);
904 	}
905 
906 	tee_device_put(teedev);
907 	wait_for_completion(&teedev->c_no_users);
908 
909 	/*
910 	 * No need to take a mutex any longer now since teedev->desc was
911 	 * set to NULL before teedev->c_no_users was completed.
912 	 */
913 
914 	teedev->pool = NULL;
915 
916 	put_device(&teedev->dev);
917 }
918 EXPORT_SYMBOL_GPL(tee_device_unregister);
919 
920 /**
921  * tee_get_drvdata() - Return driver_data pointer
922  * @teedev:	Device containing the driver_data pointer
923  * @returns the driver_data pointer supplied to tee_register().
924  */
925 void *tee_get_drvdata(struct tee_device *teedev)
926 {
927 	return dev_get_drvdata(&teedev->dev);
928 }
929 EXPORT_SYMBOL_GPL(tee_get_drvdata);
930 
931 static int __init tee_init(void)
932 {
933 	int rc;
934 
935 	tee_class = class_create(THIS_MODULE, "tee");
936 	if (IS_ERR(tee_class)) {
937 		pr_err("couldn't create class\n");
938 		return PTR_ERR(tee_class);
939 	}
940 
941 	rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
942 	if (rc) {
943 		pr_err("failed to allocate char dev region\n");
944 		class_destroy(tee_class);
945 		tee_class = NULL;
946 	}
947 
948 	return rc;
949 }
950 
951 static void __exit tee_exit(void)
952 {
953 	class_destroy(tee_class);
954 	tee_class = NULL;
955 	unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
956 }
957 
958 subsys_initcall(tee_init);
959 module_exit(tee_exit);
960 
961 MODULE_AUTHOR("Linaro");
962 MODULE_DESCRIPTION("TEE Driver");
963 MODULE_VERSION("1.0");
964 MODULE_LICENSE("GPL v2");
965