xref: /openbmc/linux/drivers/tee/optee/rpc.c (revision e00a844a)
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 	getnstimeofday64(&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.ctx_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.ctx_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 {
205 	phys_addr_t pa;
206 	struct tee_shm *shm;
207 	size_t sz;
208 	size_t n;
209 
210 	arg->ret_origin = TEEC_ORIGIN_COMMS;
211 
212 	if (!arg->num_params ||
213 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
214 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
215 		return;
216 	}
217 
218 	for (n = 1; n < arg->num_params; n++) {
219 		if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
220 			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
221 			return;
222 		}
223 	}
224 
225 	sz = arg->params[0].u.value.b;
226 	switch (arg->params[0].u.value.a) {
227 	case OPTEE_MSG_RPC_SHM_TYPE_APPL:
228 		shm = cmd_alloc_suppl(ctx, sz);
229 		break;
230 	case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
231 		shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED);
232 		break;
233 	default:
234 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
235 		return;
236 	}
237 
238 	if (IS_ERR(shm)) {
239 		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
240 		return;
241 	}
242 
243 	if (tee_shm_get_pa(shm, 0, &pa)) {
244 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
245 		goto bad;
246 	}
247 
248 	arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
249 	arg->params[0].u.tmem.buf_ptr = pa;
250 	arg->params[0].u.tmem.size = sz;
251 	arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
252 	arg->ret = TEEC_SUCCESS;
253 	return;
254 bad:
255 	tee_shm_free(shm);
256 }
257 
258 static void cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
259 {
260 	struct tee_param param;
261 
262 	param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
263 	param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
264 	param.u.value.b = tee_shm_get_id(shm);
265 	param.u.value.c = 0;
266 
267 	/*
268 	 * Match the tee_shm_get_from_id() in cmd_alloc_suppl() as secure
269 	 * world has released its reference.
270 	 *
271 	 * It's better to do this before sending the request to supplicant
272 	 * as we'd like to let the process doing the initial allocation to
273 	 * do release the last reference too in order to avoid stacking
274 	 * many pending fput() on the client process. This could otherwise
275 	 * happen if secure world does many allocate and free in a single
276 	 * invoke.
277 	 */
278 	tee_shm_put(shm);
279 
280 	optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_FREE, 1, &param);
281 }
282 
283 static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
284 					 struct optee_msg_arg *arg)
285 {
286 	struct tee_shm *shm;
287 
288 	arg->ret_origin = TEEC_ORIGIN_COMMS;
289 
290 	if (arg->num_params != 1 ||
291 	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
292 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
293 		return;
294 	}
295 
296 	shm = (struct tee_shm *)(unsigned long)arg->params[0].u.value.b;
297 	switch (arg->params[0].u.value.a) {
298 	case OPTEE_MSG_RPC_SHM_TYPE_APPL:
299 		cmd_free_suppl(ctx, shm);
300 		break;
301 	case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
302 		tee_shm_free(shm);
303 		break;
304 	default:
305 		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
306 	}
307 	arg->ret = TEEC_SUCCESS;
308 }
309 
310 static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
311 				struct tee_shm *shm)
312 {
313 	struct optee_msg_arg *arg;
314 
315 	arg = tee_shm_get_va(shm, 0);
316 	if (IS_ERR(arg)) {
317 		pr_err("%s: tee_shm_get_va %p failed\n", __func__, shm);
318 		return;
319 	}
320 
321 	switch (arg->cmd) {
322 	case OPTEE_MSG_RPC_CMD_GET_TIME:
323 		handle_rpc_func_cmd_get_time(arg);
324 		break;
325 	case OPTEE_MSG_RPC_CMD_WAIT_QUEUE:
326 		handle_rpc_func_cmd_wq(optee, arg);
327 		break;
328 	case OPTEE_MSG_RPC_CMD_SUSPEND:
329 		handle_rpc_func_cmd_wait(arg);
330 		break;
331 	case OPTEE_MSG_RPC_CMD_SHM_ALLOC:
332 		handle_rpc_func_cmd_shm_alloc(ctx, arg);
333 		break;
334 	case OPTEE_MSG_RPC_CMD_SHM_FREE:
335 		handle_rpc_func_cmd_shm_free(ctx, arg);
336 		break;
337 	default:
338 		handle_rpc_supp_cmd(ctx, arg);
339 	}
340 }
341 
342 /**
343  * optee_handle_rpc() - handle RPC from secure world
344  * @ctx:	context doing the RPC
345  * @param:	value of registers for the RPC
346  *
347  * Result of RPC is written back into @param.
348  */
349 void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param)
350 {
351 	struct tee_device *teedev = ctx->teedev;
352 	struct optee *optee = tee_get_drvdata(teedev);
353 	struct tee_shm *shm;
354 	phys_addr_t pa;
355 
356 	switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
357 	case OPTEE_SMC_RPC_FUNC_ALLOC:
358 		shm = tee_shm_alloc(ctx, param->a1, TEE_SHM_MAPPED);
359 		if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
360 			reg_pair_from_64(&param->a1, &param->a2, pa);
361 			reg_pair_from_64(&param->a4, &param->a5,
362 					 (unsigned long)shm);
363 		} else {
364 			param->a1 = 0;
365 			param->a2 = 0;
366 			param->a4 = 0;
367 			param->a5 = 0;
368 		}
369 		break;
370 	case OPTEE_SMC_RPC_FUNC_FREE:
371 		shm = reg_pair_to_ptr(param->a1, param->a2);
372 		tee_shm_free(shm);
373 		break;
374 	case OPTEE_SMC_RPC_FUNC_FOREIGN_INTR:
375 		/*
376 		 * A foreign interrupt was raised while secure world was
377 		 * executing, since they are handled in Linux a dummy RPC is
378 		 * performed to let Linux take the interrupt through the normal
379 		 * vector.
380 		 */
381 		break;
382 	case OPTEE_SMC_RPC_FUNC_CMD:
383 		shm = reg_pair_to_ptr(param->a1, param->a2);
384 		handle_rpc_func_cmd(ctx, optee, shm);
385 		break;
386 	default:
387 		pr_warn("Unknown RPC func 0x%x\n",
388 			(u32)OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0));
389 		break;
390 	}
391 
392 	param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
393 }
394