xref: /openbmc/linux/drivers/tee/optee/rpc.c (revision 2f61c664) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015-2016, Linaro Limited
4  */
5 
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7 
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/i2c.h>
11 #include <linux/slab.h>
12 #include <linux/tee_drv.h>
13 #include "optee_private.h"
14 #include "optee_smc.h"
15 #include "optee_rpc_cmd.h"
16 
17 struct wq_entry {
18 	struct list_head link;
19 	struct completion c;
20 	u32 key;
21 };
22 
23 void optee_wait_queue_init(struct optee_wait_queue *priv)
24 {
25 	mutex_init(&priv->mu);
26 	INIT_LIST_HEAD(&priv->db);
27 }
28 
29 void optee_wait_queue_exit(struct optee_wait_queue *priv)
30 {
31 	mutex_destroy(&priv->mu);
32 }
33 
34 static void handle_rpc_func_cmd_get_time(struct optee_msg_arg *arg)
35 {
36 	struct timespec64 ts;
37 
38 	if (arg->num_params != 1)
39 		goto bad;
40 	if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
41 			OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT)
42 		goto bad;
43 
44 	ktime_get_real_ts64(&ts);
45 	arg->params[0].u.value.a = ts.tv_sec;
46 	arg->params[0].u.value.b = ts.tv_nsec;
47 
48 	arg->ret = TEEC_SUCCESS;
49 	return;
50 bad:
51 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
52 }
53 
54 #if IS_REACHABLE(CONFIG_I2C)
55 static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx,
56 					     struct optee_msg_arg *arg)
57 {
58 	struct tee_param *params;
59 	struct i2c_adapter *adapter;
60 	struct i2c_msg msg = { };
61 	size_t i;
62 	int ret = -EOPNOTSUPP;
63 	u8 attr[] = {
64 		TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
65 		TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT,
66 		TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
67 		TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT,
68 	};
69 
70 	if (arg->num_params != ARRAY_SIZE(attr)) {
71 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
72 		return;
73 	}
74 
75 	params = kmalloc_array(arg->num_params, sizeof(struct tee_param),
76 			       GFP_KERNEL);
77 	if (!params) {
78 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
79 		return;
80 	}
81 
82 	if (optee_from_msg_param(params, arg->num_params, arg->params))
83 		goto bad;
84 
85 	for (i = 0; i < arg->num_params; i++) {
86 		if (params[i].attr != attr[i])
87 			goto bad;
88 	}
89 
90 	adapter = i2c_get_adapter(params[0].u.value.b);
91 	if (!adapter)
92 		goto bad;
93 
94 	if (params[1].u.value.a & OPTEE_RPC_I2C_FLAGS_TEN_BIT) {
95 		if (!i2c_check_functionality(adapter,
96 					     I2C_FUNC_10BIT_ADDR)) {
97 			i2c_put_adapter(adapter);
98 			goto bad;
99 		}
100 
101 		msg.flags = I2C_M_TEN;
102 	}
103 
104 	msg.addr = params[0].u.value.c;
105 	msg.buf  = params[2].u.memref.shm->kaddr;
106 	msg.len  = params[2].u.memref.size;
107 
108 	switch (params[0].u.value.a) {
109 	case OPTEE_RPC_I2C_TRANSFER_RD:
110 		msg.flags |= I2C_M_RD;
111 		break;
112 	case OPTEE_RPC_I2C_TRANSFER_WR:
113 		break;
114 	default:
115 		i2c_put_adapter(adapter);
116 		goto bad;
117 	}
118 
119 	ret = i2c_transfer(adapter, &msg, 1);
120 
121 	if (ret < 0) {
122 		arg->ret = TEEC_ERROR_COMMUNICATION;
123 	} else {
124 		params[3].u.value.a = msg.len;
125 		if (optee_to_msg_param(arg->params, arg->num_params, params))
126 			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
127 		else
128 			arg->ret = TEEC_SUCCESS;
129 	}
130 
131 	i2c_put_adapter(adapter);
132 	kfree(params);
133 	return;
134 bad:
135 	kfree(params);
136 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
137 }
138 #else
139 static void handle_rpc_func_cmd_i2c_transfer(struct tee_context *ctx,
140 					     struct optee_msg_arg *arg)
141 {
142 	arg->ret = TEEC_ERROR_NOT_SUPPORTED;
143 }
144 #endif
145 
146 static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key)
147 {
148 	struct wq_entry *w;
149 
150 	mutex_lock(&wq->mu);
151 
152 	list_for_each_entry(w, &wq->db, link)
153 		if (w->key == key)
154 			goto out;
155 
156 	w = kmalloc(sizeof(*w), GFP_KERNEL);
157 	if (w) {
158 		init_completion(&w->c);
159 		w->key = key;
160 		list_add_tail(&w->link, &wq->db);
161 	}
162 out:
163 	mutex_unlock(&wq->mu);
164 	return w;
165 }
166 
167 static void wq_sleep(struct optee_wait_queue *wq, u32 key)
168 {
169 	struct wq_entry *w = wq_entry_get(wq, key);
170 
171 	if (w) {
172 		wait_for_completion(&w->c);
173 		mutex_lock(&wq->mu);
174 		list_del(&w->link);
175 		mutex_unlock(&wq->mu);
176 		kfree(w);
177 	}
178 }
179 
180 static void wq_wakeup(struct optee_wait_queue *wq, u32 key)
181 {
182 	struct wq_entry *w = wq_entry_get(wq, key);
183 
184 	if (w)
185 		complete(&w->c);
186 }
187 
188 static void handle_rpc_func_cmd_wq(struct optee *optee,
189 				   struct optee_msg_arg *arg)
190 {
191 	if (arg->num_params != 1)
192 		goto bad;
193 
194 	if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
195 			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
196 		goto bad;
197 
198 	switch (arg->params[0].u.value.a) {
199 	case OPTEE_RPC_WAIT_QUEUE_SLEEP:
200 		wq_sleep(&optee->wait_queue, arg->params[0].u.value.b);
201 		break;
202 	case OPTEE_RPC_WAIT_QUEUE_WAKEUP:
203 		wq_wakeup(&optee->wait_queue, arg->params[0].u.value.b);
204 		break;
205 	default:
206 		goto bad;
207 	}
208 
209 	arg->ret = TEEC_SUCCESS;
210 	return;
211 bad:
212 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
213 }
214 
215 static void handle_rpc_func_cmd_wait(struct optee_msg_arg *arg)
216 {
217 	u32 msec_to_wait;
218 
219 	if (arg->num_params != 1)
220 		goto bad;
221 
222 	if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
223 			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
224 		goto bad;
225 
226 	msec_to_wait = arg->params[0].u.value.a;
227 
228 	/* Go to interruptible sleep */
229 	msleep_interruptible(msec_to_wait);
230 
231 	arg->ret = TEEC_SUCCESS;
232 	return;
233 bad:
234 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
235 }
236 
237 static void handle_rpc_supp_cmd(struct tee_context *ctx,
238 				struct optee_msg_arg *arg)
239 {
240 	struct tee_param *params;
241 
242 	arg->ret_origin = TEEC_ORIGIN_COMMS;
243 
244 	params = kmalloc_array(arg->num_params, sizeof(struct tee_param),
245 			       GFP_KERNEL);
246 	if (!params) {
247 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
248 		return;
249 	}
250 
251 	if (optee_from_msg_param(params, arg->num_params, arg->params)) {
252 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
253 		goto out;
254 	}
255 
256 	arg->ret = optee_supp_thrd_req(ctx, arg->cmd, arg->num_params, params);
257 
258 	if (optee_to_msg_param(arg->params, arg->num_params, params))
259 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
260 out:
261 	kfree(params);
262 }
263 
264 static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
265 {
266 	u32 ret;
267 	struct tee_param param;
268 	struct optee *optee = tee_get_drvdata(ctx->teedev);
269 	struct tee_shm *shm;
270 
271 	param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
272 	param.u.value.a = OPTEE_RPC_SHM_TYPE_APPL;
273 	param.u.value.b = sz;
274 	param.u.value.c = 0;
275 
276 	ret = optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_ALLOC, 1, &param);
277 	if (ret)
278 		return ERR_PTR(-ENOMEM);
279 
280 	mutex_lock(&optee->supp.mutex);
281 	/* Increases count as secure world doesn't have a reference */
282 	shm = tee_shm_get_from_id(optee->supp.ctx, param.u.value.c);
283 	mutex_unlock(&optee->supp.mutex);
284 	return shm;
285 }
286 
287 static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
288 					  struct optee_msg_arg *arg,
289 					  struct optee_call_ctx *call_ctx)
290 {
291 	phys_addr_t pa;
292 	struct tee_shm *shm;
293 	size_t sz;
294 	size_t n;
295 
296 	arg->ret_origin = TEEC_ORIGIN_COMMS;
297 
298 	if (!arg->num_params ||
299 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
300 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
301 		return;
302 	}
303 
304 	for (n = 1; n < arg->num_params; n++) {
305 		if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
306 			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
307 			return;
308 		}
309 	}
310 
311 	sz = arg->params[0].u.value.b;
312 	switch (arg->params[0].u.value.a) {
313 	case OPTEE_RPC_SHM_TYPE_APPL:
314 		shm = cmd_alloc_suppl(ctx, sz);
315 		break;
316 	case OPTEE_RPC_SHM_TYPE_KERNEL:
317 		shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED);
318 		break;
319 	default:
320 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
321 		return;
322 	}
323 
324 	if (IS_ERR(shm)) {
325 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
326 		return;
327 	}
328 
329 	if (tee_shm_get_pa(shm, 0, &pa)) {
330 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
331 		goto bad;
332 	}
333 
334 	sz = tee_shm_get_size(shm);
335 
336 	if (tee_shm_is_registered(shm)) {
337 		struct page **pages;
338 		u64 *pages_list;
339 		size_t page_num;
340 
341 		pages = tee_shm_get_pages(shm, &page_num);
342 		if (!pages || !page_num) {
343 			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
344 			goto bad;
345 		}
346 
347 		pages_list = optee_allocate_pages_list(page_num);
348 		if (!pages_list) {
349 			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
350 			goto bad;
351 		}
352 
353 		call_ctx->pages_list = pages_list;
354 		call_ctx->num_entries = page_num;
355 
356 		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
357 				      OPTEE_MSG_ATTR_NONCONTIG;
358 		/*
359 		 * In the least bits of u.tmem.buf_ptr we store buffer offset
360 		 * from 4k page, as described in OP-TEE ABI.
361 		 */
362 		arg->params[0].u.tmem.buf_ptr = virt_to_phys(pages_list) |
363 			(tee_shm_get_page_offset(shm) &
364 			 (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
365 		arg->params[0].u.tmem.size = tee_shm_get_size(shm);
366 		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
367 
368 		optee_fill_pages_list(pages_list, pages, page_num,
369 				      tee_shm_get_page_offset(shm));
370 	} else {
371 		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
372 		arg->params[0].u.tmem.buf_ptr = pa;
373 		arg->params[0].u.tmem.size = sz;
374 		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
375 	}
376 
377 	arg->ret = TEEC_SUCCESS;
378 	return;
379 bad:
380 	tee_shm_free(shm);
381 }
382 
383 static void cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
384 {
385 	struct tee_param param;
386 
387 	param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
388 	param.u.value.a = OPTEE_RPC_SHM_TYPE_APPL;
389 	param.u.value.b = tee_shm_get_id(shm);
390 	param.u.value.c = 0;
391 
392 	/*
393 	 * Match the tee_shm_get_from_id() in cmd_alloc_suppl() as secure
394 	 * world has released its reference.
395 	 *
396 	 * It's better to do this before sending the request to supplicant
397 	 * as we'd like to let the process doing the initial allocation to
398 	 * do release the last reference too in order to avoid stacking
399 	 * many pending fput() on the client process. This could otherwise
400 	 * happen if secure world does many allocate and free in a single
401 	 * invoke.
402 	 */
403 	tee_shm_put(shm);
404 
405 	optee_supp_thrd_req(ctx, OPTEE_RPC_CMD_SHM_FREE, 1, &param);
406 }
407 
408 static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
409 					 struct optee_msg_arg *arg)
410 {
411 	struct tee_shm *shm;
412 
413 	arg->ret_origin = TEEC_ORIGIN_COMMS;
414 
415 	if (arg->num_params != 1 ||
416 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
417 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
418 		return;
419 	}
420 
421 	shm = (struct tee_shm *)(unsigned long)arg->params[0].u.value.b;
422 	switch (arg->params[0].u.value.a) {
423 	case OPTEE_RPC_SHM_TYPE_APPL:
424 		cmd_free_suppl(ctx, shm);
425 		break;
426 	case OPTEE_RPC_SHM_TYPE_KERNEL:
427 		tee_shm_free(shm);
428 		break;
429 	default:
430 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
431 	}
432 	arg->ret = TEEC_SUCCESS;
433 }
434 
435 static void free_pages_list(struct optee_call_ctx *call_ctx)
436 {
437 	if (call_ctx->pages_list) {
438 		optee_free_pages_list(call_ctx->pages_list,
439 				      call_ctx->num_entries);
440 		call_ctx->pages_list = NULL;
441 		call_ctx->num_entries = 0;
442 	}
443 }
444 
445 void optee_rpc_finalize_call(struct optee_call_ctx *call_ctx)
446 {
447 	free_pages_list(call_ctx);
448 }
449 
450 static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
451 				struct tee_shm *shm,
452 				struct optee_call_ctx *call_ctx)
453 {
454 	struct optee_msg_arg *arg;
455 
456 	arg = tee_shm_get_va(shm, 0);
457 	if (IS_ERR(arg)) {
458 		pr_err("%s: tee_shm_get_va %p failed\n", __func__, shm);
459 		return;
460 	}
461 
462 	switch (arg->cmd) {
463 	case OPTEE_RPC_CMD_GET_TIME:
464 		handle_rpc_func_cmd_get_time(arg);
465 		break;
466 	case OPTEE_RPC_CMD_WAIT_QUEUE:
467 		handle_rpc_func_cmd_wq(optee, arg);
468 		break;
469 	case OPTEE_RPC_CMD_SUSPEND:
470 		handle_rpc_func_cmd_wait(arg);
471 		break;
472 	case OPTEE_RPC_CMD_SHM_ALLOC:
473 		free_pages_list(call_ctx);
474 		handle_rpc_func_cmd_shm_alloc(ctx, arg, call_ctx);
475 		break;
476 	case OPTEE_RPC_CMD_SHM_FREE:
477 		handle_rpc_func_cmd_shm_free(ctx, arg);
478 		break;
479 	case OPTEE_RPC_CMD_I2C_TRANSFER:
480 		handle_rpc_func_cmd_i2c_transfer(ctx, arg);
481 		break;
482 	default:
483 		handle_rpc_supp_cmd(ctx, arg);
484 	}
485 }
486 
487 /**
488  * optee_handle_rpc() - handle RPC from secure world
489  * @ctx:	context doing the RPC
490  * @param:	value of registers for the RPC
491  * @call_ctx:	call context. Preserved during one OP-TEE invocation
492  *
493  * Result of RPC is written back into @param.
494  */
495 void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param,
496 		      struct optee_call_ctx *call_ctx)
497 {
498 	struct tee_device *teedev = ctx->teedev;
499 	struct optee *optee = tee_get_drvdata(teedev);
500 	struct tee_shm *shm;
501 	phys_addr_t pa;
502 
503 	switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
504 	case OPTEE_SMC_RPC_FUNC_ALLOC:
505 		shm = tee_shm_alloc(ctx, param->a1, TEE_SHM_MAPPED);
506 		if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
507 			reg_pair_from_64(&param->a1, &param->a2, pa);
508 			reg_pair_from_64(&param->a4, &param->a5,
509 					 (unsigned long)shm);
510 		} else {
511 			param->a1 = 0;
512 			param->a2 = 0;
513 			param->a4 = 0;
514 			param->a5 = 0;
515 		}
516 		break;
517 	case OPTEE_SMC_RPC_FUNC_FREE:
518 		shm = reg_pair_to_ptr(param->a1, param->a2);
519 		tee_shm_free(shm);
520 		break;
521 	case OPTEE_SMC_RPC_FUNC_FOREIGN_INTR:
522 		/*
523 		 * A foreign interrupt was raised while secure world was
524 		 * executing, since they are handled in Linux a dummy RPC is
525 		 * performed to let Linux take the interrupt through the normal
526 		 * vector.
527 		 */
528 		break;
529 	case OPTEE_SMC_RPC_FUNC_CMD:
530 		shm = reg_pair_to_ptr(param->a1, param->a2);
531 		handle_rpc_func_cmd(ctx, optee, shm, call_ctx);
532 		break;
533 	default:
534 		pr_warn("Unknown RPC func 0x%x\n",
535 			(u32)OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0));
536 		break;
537 	}
538 
539 	param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
540 }
541