xref: /linux/drivers/tee/qcomtee/qcomtee_msg.h (revision 38057e323657695ec8f814aff0cdd1c7e00d3e9b)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
4  */
5 
6 #ifndef QCOMTEE_MSG_H
7 #define QCOMTEE_MSG_H
8 
9 #include <linux/bitfield.h>
10 
11 /**
12  * DOC: ''Qualcomm TEE'' (QTEE) Transport Message
13  *
14  * There are two buffers shared with QTEE: inbound and outbound buffers.
15  * The inbound buffer is used for direct object invocation, and the outbound
16  * buffer is used to make a request from QTEE to the kernel; i.e., a callback
17  * request.
18  *
19  * The unused tail of the outbound buffer is also used for sending and
20  * receiving asynchronous messages. An asynchronous message is independent of
21  * the current object invocation (i.e., contents of the inbound buffer) or
22  * callback request (i.e., the head of the outbound buffer); see
23  * qcomtee_get_async_buffer(). It is used by endpoints (QTEE or kernel) as an
24  * optimization to reduce the number of context switches between the secure and
25  * non-secure worlds.
26  *
27  * For instance, QTEE never sends an explicit callback request to release an
28  * object in the kernel. Instead, it sends asynchronous release messages in the
29  * outbound buffer when QTEE returns from the previous direct object invocation,
30  * or appends asynchronous release messages after the current callback request.
31  *
32  * QTEE supports two types of arguments in a message: buffer and object
33  * arguments. Depending on the direction of data flow, they could be input
34  * buffer (IO) to QTEE, output buffer (OB) from QTEE, input object (IO) to QTEE,
35  * or output object (OO) from QTEE. Object arguments hold object IDs. Buffer
36  * arguments hold (offset, size) pairs into the inbound or outbound buffers.
37  *
38  * QTEE holds an object table for objects it hosts and exposes to the kernel.
39  * An object ID is an index to the object table in QTEE.
40  *
41  * For the direct object invocation message format in the inbound buffer, see
42  * &struct qcomtee_msg_object_invoke. For the callback request message format
43  * in the outbound buffer, see &struct qcomtee_msg_callback. For the message
44  * format for asynchronous messages in the outbound buffer, see
45  * &struct qcomtee_async_msg_hdr.
46  */
47 
48 /**
49  * define QCOMTEE_MSG_OBJECT_NS_BIT - Non-secure bit
50  *
51  * Object ID is a globally unique 32-bit number. IDs referencing objects
52  * in the kernel should have %QCOMTEE_MSG_OBJECT_NS_BIT set.
53  */
54 #define QCOMTEE_MSG_OBJECT_NS_BIT BIT(31)
55 
56 /* Static object IDs recognized by QTEE. */
57 #define QCOMTEE_MSG_OBJECT_NULL (0U)
58 #define QCOMTEE_MSG_OBJECT_ROOT (1U)
59 
60 /* Definitions from QTEE as part of the transport protocol. */
61 
62 /* qcomtee_msg_arg is an argument as recognized by QTEE. */
63 union qcomtee_msg_arg {
64 	struct {
65 		u32 offset;
66 		u32 size;
67 	} b;
68 	u32 o;
69 };
70 
71 /* BI and BO payloads in QTEE messages should be at 64-bit boundaries. */
72 #define qcomtee_msg_offset_align(o) ALIGN((o), sizeof(u64))
73 
74 /* Operations for objects are 32-bit. Transport uses the upper 16 bits. */
75 #define QCOMTEE_MSG_OBJECT_OP_MASK GENMASK(15, 0)
76 
77 /* Reserved Operation IDs sent to QTEE: */
78 /* QCOMTEE_MSG_OBJECT_OP_RELEASE - Reduces the refcount and releases the object.
79  * QCOMTEE_MSG_OBJECT_OP_RETAIN  - Increases the refcount.
80  *
81  * These operation IDs are valid for all objects.
82  */
83 
84 #define QCOMTEE_MSG_OBJECT_OP_RELEASE (QCOMTEE_MSG_OBJECT_OP_MASK - 0)
85 #define QCOMTEE_MSG_OBJECT_OP_RETAIN  (QCOMTEE_MSG_OBJECT_OP_MASK - 1)
86 
87 /* Subset of operations supported by QTEE root object. */
88 
89 #define QCOMTEE_ROOT_OP_REG_WITH_CREDENTIALS	5
90 #define QCOMTEE_ROOT_OP_NOTIFY_DOMAIN_CHANGE	4
91 #define QCOMTEE_ROOT_OP_ADCI_ACCEPT		8
92 #define QCOMTEE_ROOT_OP_ADCI_SHUTDOWN		9
93 
94 /* Subset of operations supported by client_env object. */
95 
96 #define QCOMTEE_CLIENT_ENV_OPEN 0
97 
98 /* List of available QTEE service UIDs and subset of operations. */
99 
100 #define QCOMTEE_FEATURE_VER_UID		2033
101 #define QCOMTEE_FEATURE_VER_OP_GET	0
102 /* Get QTEE version number. */
103 #define QCOMTEE_FEATURE_VER_OP_GET_QTEE_ID 10
104 #define QTEE_VERSION_GET_MAJOR(x) (((x) >> 22) & 0xffU)
105 #define QTEE_VERSION_GET_MINOR(x) (((x) >> 12) & 0xffU)
106 #define QTEE_VERSION_GET_PATCH(x) ((x) >> 0 & 0xfffU)
107 
108 /* Response types as returned from qcomtee_object_invoke_ctx_invoke(). */
109 
110 /* The message contains a callback request. */
111 #define QCOMTEE_RESULT_INBOUND_REQ_NEEDED 3
112 
113 /**
114  * struct qcomtee_msg_object_invoke - Direct object invocation message.
115  * @ctx: object ID hosted in QTEE.
116  * @op: operation for the object.
117  * @counts: number of different types of arguments in @args.
118  * @args: array of arguments.
119  *
120  * @counts consists of 4 * 4-bit fields. Bits 0 - 3 represent the number of
121  * input buffers, bits 4 - 7 represent the number of output buffers,
122  * bits 8 - 11 represent the number of input objects, and bits 12 - 15
123  * represent the number of output objects. The remaining bits should be zero.
124  *
125  *    15            12 11             8 7              4 3              0
126  *   +----------------+----------------+----------------+----------------+
127  *   |  #OO objects   |  #IO objects   |  #OB buffers   |  #IB buffers   |
128  *   +----------------+----------------+----------------+----------------+
129  *
130  * The maximum number of arguments of each type is defined by
131  * %QCOMTEE_ARGS_PER_TYPE.
132  */
133 struct qcomtee_msg_object_invoke {
134 	u32 cxt;
135 	u32 op;
136 	u32 counts;
137 	union qcomtee_msg_arg args[];
138 };
139 
140 /* Bit masks for the four 4-bit nibbles holding the counts. */
141 #define QCOMTEE_MASK_IB GENMASK(3, 0)
142 #define QCOMTEE_MASK_OB GENMASK(7, 4)
143 #define QCOMTEE_MASK_IO GENMASK(11, 8)
144 #define QCOMTEE_MASK_OO GENMASK(15, 12)
145 
146 /**
147  * struct qcomtee_msg_callback - Callback request message.
148  * @result: result of operation @op on the object referenced by @cxt.
149  * @cxt: object ID hosted in the kernel.
150  * @op: operation for the object.
151  * @counts: number of different types of arguments in @args.
152  * @args: array of arguments.
153  *
154  * For details of @counts, see &qcomtee_msg_object_invoke.counts.
155  */
156 struct qcomtee_msg_callback {
157 	u32 result;
158 	u32 cxt;
159 	u32 op;
160 	u32 counts;
161 	union qcomtee_msg_arg args[];
162 };
163 
164 /* Offset in the message for the beginning of the buffer argument's contents. */
165 #define qcomtee_msg_buffer_args(t, n) \
166 	qcomtee_msg_offset_align(struct_size_t(t, args, n))
167 /* Pointer to the beginning of a buffer argument's content at an offset. */
168 #define qcomtee_msg_offset_to_ptr(m, off) ((void *)&((char *)(m))[(off)])
169 
170 /* Some helpers to manage msg.counts. */
171 
172 static inline unsigned int qcomtee_msg_num_ib(u32 counts)
173 {
174 	return FIELD_GET(QCOMTEE_MASK_IB, counts);
175 }
176 
177 static inline unsigned int qcomtee_msg_num_ob(u32 counts)
178 {
179 	return FIELD_GET(QCOMTEE_MASK_OB, counts);
180 }
181 
182 static inline unsigned int qcomtee_msg_num_io(u32 counts)
183 {
184 	return FIELD_GET(QCOMTEE_MASK_IO, counts);
185 }
186 
187 static inline unsigned int qcomtee_msg_num_oo(u32 counts)
188 {
189 	return FIELD_GET(QCOMTEE_MASK_OO, counts);
190 }
191 
192 static inline unsigned int qcomtee_msg_idx_ib(u32 counts)
193 {
194 	return 0;
195 }
196 
197 static inline unsigned int qcomtee_msg_idx_ob(u32 counts)
198 {
199 	return qcomtee_msg_num_ib(counts);
200 }
201 
202 static inline unsigned int qcomtee_msg_idx_io(u32 counts)
203 {
204 	return qcomtee_msg_idx_ob(counts) + qcomtee_msg_num_ob(counts);
205 }
206 
207 static inline unsigned int qcomtee_msg_idx_oo(u32 counts)
208 {
209 	return qcomtee_msg_idx_io(counts) + qcomtee_msg_num_io(counts);
210 }
211 
212 #define qcomtee_msg_for_each(i, first, num) \
213 	for ((i) = (first); (i) < (first) + (num); (i)++)
214 
215 #define qcomtee_msg_for_each_input_buffer(i, m)                  \
216 	qcomtee_msg_for_each(i, qcomtee_msg_idx_ib((m)->counts), \
217 			     qcomtee_msg_num_ib((m)->counts))
218 
219 #define qcomtee_msg_for_each_output_buffer(i, m)                 \
220 	qcomtee_msg_for_each(i, qcomtee_msg_idx_ob((m)->counts), \
221 			     qcomtee_msg_num_ob((m)->counts))
222 
223 #define qcomtee_msg_for_each_input_object(i, m)                  \
224 	qcomtee_msg_for_each(i, qcomtee_msg_idx_io((m)->counts), \
225 			     qcomtee_msg_num_io((m)->counts))
226 
227 #define qcomtee_msg_for_each_output_object(i, m)                 \
228 	qcomtee_msg_for_each(i, qcomtee_msg_idx_oo((m)->counts), \
229 			     qcomtee_msg_num_oo((m)->counts))
230 
231 /* Sum of arguments in a message. */
232 #define qcomtee_msg_args(m) \
233 	(qcomtee_msg_idx_oo((m)->counts) + qcomtee_msg_num_oo((m)->counts))
234 
235 static inline void qcomtee_msg_init(struct qcomtee_msg_object_invoke *msg,
236 				    u32 cxt, u32 op, int in_buffer,
237 				    int out_buffer, int in_object,
238 				    int out_object)
239 {
240 	u32 counts = 0;
241 
242 	counts |= (in_buffer & 0xfU);
243 	counts |= ((out_buffer - in_buffer) & 0xfU) << 4;
244 	counts |= ((in_object - out_buffer) & 0xfU) << 8;
245 	counts |= ((out_object - in_object) & 0xfU) << 12;
246 
247 	msg->cxt = cxt;
248 	msg->op = op;
249 	msg->counts = counts;
250 }
251 
252 /* Generic error codes. */
253 #define QCOMTEE_MSG_OK			0 /* non-specific success code. */
254 #define QCOMTEE_MSG_ERROR		1 /* non-specific error. */
255 #define QCOMTEE_MSG_ERROR_INVALID	2 /* unsupported/unrecognized request. */
256 #define QCOMTEE_MSG_ERROR_SIZE_IN	3 /* supplied buffer/string too large. */
257 #define QCOMTEE_MSG_ERROR_SIZE_OUT	4 /* supplied output buffer too small. */
258 #define QCOMTEE_MSG_ERROR_USERBASE	10 /* start of user-defined error range. */
259 
260 /* Transport layer error codes. */
261 #define QCOMTEE_MSG_ERROR_DEFUNCT	-90 /* object no longer exists. */
262 #define QCOMTEE_MSG_ERROR_ABORT		-91 /* calling thread must exit. */
263 #define QCOMTEE_MSG_ERROR_BADOBJ	-92 /* invalid object context. */
264 #define QCOMTEE_MSG_ERROR_NOSLOTS	-93 /* caller's object table full. */
265 #define QCOMTEE_MSG_ERROR_MAXARGS	-94 /* too many args. */
266 #define QCOMTEE_MSG_ERROR_MAXDATA	-95 /* buffers too large. */
267 #define QCOMTEE_MSG_ERROR_UNAVAIL	-96 /* the request could not be processed. */
268 #define QCOMTEE_MSG_ERROR_KMEM		-97 /* kernel out of memory. */
269 #define QCOMTEE_MSG_ERROR_REMOTE	-98 /* local method sent to remote object. */
270 #define QCOMTEE_MSG_ERROR_BUSY		-99 /* Object is busy. */
271 #define QCOMTEE_MSG_ERROR_TIMEOUT	-103 /* Call Back Object invocation timed out. */
272 
273 static inline void qcomtee_msg_set_result(struct qcomtee_msg_callback *cb_msg,
274 					  int err)
275 {
276 	if (!err) {
277 		cb_msg->result = QCOMTEE_MSG_OK;
278 	} else if (err < 0) {
279 		/* If err < 0, then it is a transport error. */
280 		switch (err) {
281 		case -ENOMEM:
282 			cb_msg->result = QCOMTEE_MSG_ERROR_KMEM;
283 			break;
284 		case -ENODEV:
285 			cb_msg->result = QCOMTEE_MSG_ERROR_DEFUNCT;
286 			break;
287 		case -ENOSPC:
288 		case -EBUSY:
289 			cb_msg->result = QCOMTEE_MSG_ERROR_BUSY;
290 			break;
291 		case -EBADF:
292 		case -EINVAL:
293 			cb_msg->result = QCOMTEE_MSG_ERROR_UNAVAIL;
294 			break;
295 		default:
296 			cb_msg->result = QCOMTEE_MSG_ERROR;
297 		}
298 	} else {
299 		/* If err > 0, then it is user defined error, pass it as is. */
300 		cb_msg->result = err;
301 	}
302 }
303 
304 #endif /* QCOMTEE_MSG_H */
305