xref: /openbmc/linux/drivers/tee/optee/rpc.c (revision 0c874100)
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) KBUILD_MODNAME ": " fmt
16 
17 #include <linux/delay.h>
18 #include <linux/device.h>
19 #include <linux/slab.h>
20 #include <linux/tee_drv.h>
21 #include "optee_private.h"
22 #include "optee_smc.h"
23 
24 struct wq_entry {
25 	struct list_head link;
26 	struct completion c;
27 	u32 key;
28 };
29 
30 void optee_wait_queue_init(struct optee_wait_queue *priv)
31 {
32 	mutex_init(&priv->mu);
33 	INIT_LIST_HEAD(&priv->db);
34 }
35 
36 void optee_wait_queue_exit(struct optee_wait_queue *priv)
37 {
38 	mutex_destroy(&priv->mu);
39 }
40 
41 static void handle_rpc_func_cmd_get_time(struct optee_msg_arg *arg)
42 {
43 	struct timespec64 ts;
44 
45 	if (arg->num_params != 1)
46 		goto bad;
47 	if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
48 			OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT)
49 		goto bad;
50 
51 	ktime_get_real_ts64(&ts);
52 	arg->params[0].u.value.a = ts.tv_sec;
53 	arg->params[0].u.value.b = ts.tv_nsec;
54 
55 	arg->ret = TEEC_SUCCESS;
56 	return;
57 bad:
58 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
59 }
60 
61 static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key)
62 {
63 	struct wq_entry *w;
64 
65 	mutex_lock(&wq->mu);
66 
67 	list_for_each_entry(w, &wq->db, link)
68 		if (w->key == key)
69 			goto out;
70 
71 	w = kmalloc(sizeof(*w), GFP_KERNEL);
72 	if (w) {
73 		init_completion(&w->c);
74 		w->key = key;
75 		list_add_tail(&w->link, &wq->db);
76 	}
77 out:
78 	mutex_unlock(&wq->mu);
79 	return w;
80 }
81 
82 static void wq_sleep(struct optee_wait_queue *wq, u32 key)
83 {
84 	struct wq_entry *w = wq_entry_get(wq, key);
85 
86 	if (w) {
87 		wait_for_completion(&w->c);
88 		mutex_lock(&wq->mu);
89 		list_del(&w->link);
90 		mutex_unlock(&wq->mu);
91 		kfree(w);
92 	}
93 }
94 
95 static void wq_wakeup(struct optee_wait_queue *wq, u32 key)
96 {
97 	struct wq_entry *w = wq_entry_get(wq, key);
98 
99 	if (w)
100 		complete(&w->c);
101 }
102 
103 static void handle_rpc_func_cmd_wq(struct optee *optee,
104 				   struct optee_msg_arg *arg)
105 {
106 	if (arg->num_params != 1)
107 		goto bad;
108 
109 	if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
110 			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
111 		goto bad;
112 
113 	switch (arg->params[0].u.value.a) {
114 	case OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP:
115 		wq_sleep(&optee->wait_queue, arg->params[0].u.value.b);
116 		break;
117 	case OPTEE_MSG_RPC_WAIT_QUEUE_WAKEUP:
118 		wq_wakeup(&optee->wait_queue, arg->params[0].u.value.b);
119 		break;
120 	default:
121 		goto bad;
122 	}
123 
124 	arg->ret = TEEC_SUCCESS;
125 	return;
126 bad:
127 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
128 }
129 
130 static void handle_rpc_func_cmd_wait(struct optee_msg_arg *arg)
131 {
132 	u32 msec_to_wait;
133 
134 	if (arg->num_params != 1)
135 		goto bad;
136 
137 	if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
138 			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
139 		goto bad;
140 
141 	msec_to_wait = arg->params[0].u.value.a;
142 
143 	/* Go to interruptible sleep */
144 	msleep_interruptible(msec_to_wait);
145 
146 	arg->ret = TEEC_SUCCESS;
147 	return;
148 bad:
149 	arg->ret = TEEC_ERROR_BAD_PARAMETERS;
150 }
151 
152 static void handle_rpc_supp_cmd(struct tee_context *ctx,
153 				struct optee_msg_arg *arg)
154 {
155 	struct tee_param *params;
156 
157 	arg->ret_origin = TEEC_ORIGIN_COMMS;
158 
159 	params = kmalloc_array(arg->num_params, sizeof(struct tee_param),
160 			       GFP_KERNEL);
161 	if (!params) {
162 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
163 		return;
164 	}
165 
166 	if (optee_from_msg_param(params, arg->num_params, arg->params)) {
167 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
168 		goto out;
169 	}
170 
171 	arg->ret = optee_supp_thrd_req(ctx, arg->cmd, arg->num_params, params);
172 
173 	if (optee_to_msg_param(arg->params, arg->num_params, params))
174 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
175 out:
176 	kfree(params);
177 }
178 
179 static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
180 {
181 	u32 ret;
182 	struct tee_param param;
183 	struct optee *optee = tee_get_drvdata(ctx->teedev);
184 	struct tee_shm *shm;
185 
186 	param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
187 	param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
188 	param.u.value.b = sz;
189 	param.u.value.c = 0;
190 
191 	ret = optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_ALLOC, 1, &param);
192 	if (ret)
193 		return ERR_PTR(-ENOMEM);
194 
195 	mutex_lock(&optee->supp.mutex);
196 	/* Increases count as secure world doesn't have a reference */
197 	shm = tee_shm_get_from_id(optee->supp.ctx, param.u.value.c);
198 	mutex_unlock(&optee->supp.mutex);
199 	return shm;
200 }
201 
202 static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
203 					  struct optee_msg_arg *arg,
204 					  struct optee_call_ctx *call_ctx)
205 {
206 	phys_addr_t pa;
207 	struct tee_shm *shm;
208 	size_t sz;
209 	size_t n;
210 
211 	arg->ret_origin = TEEC_ORIGIN_COMMS;
212 
213 	if (!arg->num_params ||
214 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
215 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
216 		return;
217 	}
218 
219 	for (n = 1; n < arg->num_params; n++) {
220 		if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
221 			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
222 			return;
223 		}
224 	}
225 
226 	sz = arg->params[0].u.value.b;
227 	switch (arg->params[0].u.value.a) {
228 	case OPTEE_MSG_RPC_SHM_TYPE_APPL:
229 		shm = cmd_alloc_suppl(ctx, sz);
230 		break;
231 	case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
232 		shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED);
233 		break;
234 	default:
235 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
236 		return;
237 	}
238 
239 	if (IS_ERR(shm)) {
240 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
241 		return;
242 	}
243 
244 	if (tee_shm_get_pa(shm, 0, &pa)) {
245 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
246 		goto bad;
247 	}
248 
249 	sz = tee_shm_get_size(shm);
250 
251 	if (tee_shm_is_registered(shm)) {
252 		struct page **pages;
253 		u64 *pages_list;
254 		size_t page_num;
255 
256 		pages = tee_shm_get_pages(shm, &page_num);
257 		if (!pages || !page_num) {
258 			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
259 			goto bad;
260 		}
261 
262 		pages_list = optee_allocate_pages_list(page_num);
263 		if (!pages_list) {
264 			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
265 			goto bad;
266 		}
267 
268 		call_ctx->pages_list = pages_list;
269 		call_ctx->num_entries = page_num;
270 
271 		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
272 				      OPTEE_MSG_ATTR_NONCONTIG;
273 		/*
274 		 * In the least bits of u.tmem.buf_ptr we store buffer offset
275 		 * from 4k page, as described in OP-TEE ABI.
276 		 */
277 		arg->params[0].u.tmem.buf_ptr = virt_to_phys(pages_list) |
278 			(tee_shm_get_page_offset(shm) &
279 			 (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
280 		arg->params[0].u.tmem.size = tee_shm_get_size(shm);
281 		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
282 
283 		optee_fill_pages_list(pages_list, pages, page_num,
284 				      tee_shm_get_page_offset(shm));
285 	} else {
286 		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
287 		arg->params[0].u.tmem.buf_ptr = pa;
288 		arg->params[0].u.tmem.size = sz;
289 		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
290 	}
291 
292 	arg->ret = TEEC_SUCCESS;
293 	return;
294 bad:
295 	tee_shm_free(shm);
296 }
297 
298 static void cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
299 {
300 	struct tee_param param;
301 
302 	param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
303 	param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
304 	param.u.value.b = tee_shm_get_id(shm);
305 	param.u.value.c = 0;
306 
307 	/*
308 	 * Match the tee_shm_get_from_id() in cmd_alloc_suppl() as secure
309 	 * world has released its reference.
310 	 *
311 	 * It's better to do this before sending the request to supplicant
312 	 * as we'd like to let the process doing the initial allocation to
313 	 * do release the last reference too in order to avoid stacking
314 	 * many pending fput() on the client process. This could otherwise
315 	 * happen if secure world does many allocate and free in a single
316 	 * invoke.
317 	 */
318 	tee_shm_put(shm);
319 
320 	optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_FREE, 1, &param);
321 }
322 
323 static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
324 					 struct optee_msg_arg *arg)
325 {
326 	struct tee_shm *shm;
327 
328 	arg->ret_origin = TEEC_ORIGIN_COMMS;
329 
330 	if (arg->num_params != 1 ||
331 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
332 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
333 		return;
334 	}
335 
336 	shm = (struct tee_shm *)(unsigned long)arg->params[0].u.value.b;
337 	switch (arg->params[0].u.value.a) {
338 	case OPTEE_MSG_RPC_SHM_TYPE_APPL:
339 		cmd_free_suppl(ctx, shm);
340 		break;
341 	case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
342 		tee_shm_free(shm);
343 		break;
344 	default:
345 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
346 	}
347 	arg->ret = TEEC_SUCCESS;
348 }
349 
350 static void free_pages_list(struct optee_call_ctx *call_ctx)
351 {
352 	if (call_ctx->pages_list) {
353 		optee_free_pages_list(call_ctx->pages_list,
354 				      call_ctx->num_entries);
355 		call_ctx->pages_list = NULL;
356 		call_ctx->num_entries = 0;
357 	}
358 }
359 
360 void optee_rpc_finalize_call(struct optee_call_ctx *call_ctx)
361 {
362 	free_pages_list(call_ctx);
363 }
364 
365 static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
366 				struct tee_shm *shm,
367 				struct optee_call_ctx *call_ctx)
368 {
369 	struct optee_msg_arg *arg;
370 
371 	arg = tee_shm_get_va(shm, 0);
372 	if (IS_ERR(arg)) {
373 		pr_err("%s: tee_shm_get_va %p failed\n", __func__, shm);
374 		return;
375 	}
376 
377 	switch (arg->cmd) {
378 	case OPTEE_MSG_RPC_CMD_GET_TIME:
379 		handle_rpc_func_cmd_get_time(arg);
380 		break;
381 	case OPTEE_MSG_RPC_CMD_WAIT_QUEUE:
382 		handle_rpc_func_cmd_wq(optee, arg);
383 		break;
384 	case OPTEE_MSG_RPC_CMD_SUSPEND:
385 		handle_rpc_func_cmd_wait(arg);
386 		break;
387 	case OPTEE_MSG_RPC_CMD_SHM_ALLOC:
388 		free_pages_list(call_ctx);
389 		handle_rpc_func_cmd_shm_alloc(ctx, arg, call_ctx);
390 		break;
391 	case OPTEE_MSG_RPC_CMD_SHM_FREE:
392 		handle_rpc_func_cmd_shm_free(ctx, arg);
393 		break;
394 	default:
395 		handle_rpc_supp_cmd(ctx, arg);
396 	}
397 }
398 
399 /**
400  * optee_handle_rpc() - handle RPC from secure world
401  * @ctx:	context doing the RPC
402  * @param:	value of registers for the RPC
403  * @call_ctx:	call context. Preserved during one OP-TEE invocation
404  *
405  * Result of RPC is written back into @param.
406  */
407 void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param,
408 		      struct optee_call_ctx *call_ctx)
409 {
410 	struct tee_device *teedev = ctx->teedev;
411 	struct optee *optee = tee_get_drvdata(teedev);
412 	struct tee_shm *shm;
413 	phys_addr_t pa;
414 
415 	switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
416 	case OPTEE_SMC_RPC_FUNC_ALLOC:
417 		shm = tee_shm_alloc(ctx, param->a1, TEE_SHM_MAPPED);
418 		if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
419 			reg_pair_from_64(&param->a1, &param->a2, pa);
420 			reg_pair_from_64(&param->a4, &param->a5,
421 					 (unsigned long)shm);
422 		} else {
423 			param->a1 = 0;
424 			param->a2 = 0;
425 			param->a4 = 0;
426 			param->a5 = 0;
427 		}
428 		break;
429 	case OPTEE_SMC_RPC_FUNC_FREE:
430 		shm = reg_pair_to_ptr(param->a1, param->a2);
431 		tee_shm_free(shm);
432 		break;
433 	case OPTEE_SMC_RPC_FUNC_FOREIGN_INTR:
434 		/*
435 		 * A foreign interrupt was raised while secure world was
436 		 * executing, since they are handled in Linux a dummy RPC is
437 		 * performed to let Linux take the interrupt through the normal
438 		 * vector.
439 		 */
440 		break;
441 	case OPTEE_SMC_RPC_FUNC_CMD:
442 		shm = reg_pair_to_ptr(param->a1, param->a2);
443 		handle_rpc_func_cmd(ctx, optee, shm, call_ctx);
444 		break;
445 	default:
446 		pr_warn("Unknown RPC func 0x%x\n",
447 			(u32)OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0));
448 		break;
449 	}
450 
451 	param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
452 }
453