1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * System Control and Management Interface (SCMI) Message Protocol |
4 | * protocols common header file containing some definitions, structures |
5 | * and function prototypes used in all the different SCMI protocols. |
6 | * |
7 | * Copyright (C) 2022 ARM Ltd. |
8 | */ |
9 | #ifndef _SCMI_PROTOCOLS_H |
10 | #define _SCMI_PROTOCOLS_H |
11 | |
12 | #include <linux/bitfield.h> |
13 | #include <linux/completion.h> |
14 | #include <linux/device.h> |
15 | #include <linux/errno.h> |
16 | #include <linux/kernel.h> |
17 | #include <linux/hashtable.h> |
18 | #include <linux/list.h> |
19 | #include <linux/module.h> |
20 | #include <linux/refcount.h> |
21 | #include <linux/scmi_protocol.h> |
22 | #include <linux/spinlock.h> |
23 | #include <linux/types.h> |
24 | |
25 | #include <asm/unaligned.h> |
26 | |
27 | #define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0) |
28 | #define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16) |
29 | #define PROTOCOL_REV_MAJOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))) |
30 | #define PROTOCOL_REV_MINOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))) |
31 | |
32 | enum scmi_common_cmd { |
33 | PROTOCOL_VERSION = 0x0, |
34 | PROTOCOL_ATTRIBUTES = 0x1, |
35 | PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, |
36 | NEGOTIATE_PROTOCOL_VERSION = 0x10, |
37 | }; |
38 | |
39 | /** |
40 | * struct scmi_msg_resp_prot_version - Response for a message |
41 | * |
42 | * @minor_version: Minor version of the ABI that firmware supports |
43 | * @major_version: Major version of the ABI that firmware supports |
44 | * |
45 | * In general, ABI version changes follow the rule that minor version increments |
46 | * are backward compatible. Major revision changes in ABI may not be |
47 | * backward compatible. |
48 | * |
49 | * Response to a generic message with message type SCMI_MSG_VERSION |
50 | */ |
51 | struct scmi_msg_resp_prot_version { |
52 | __le16 minor_version; |
53 | __le16 major_version; |
54 | }; |
55 | |
56 | /** |
57 | * struct scmi_msg - Message(Tx/Rx) structure |
58 | * |
59 | * @buf: Buffer pointer |
60 | * @len: Length of data in the Buffer |
61 | */ |
62 | struct scmi_msg { |
63 | void *buf; |
64 | size_t len; |
65 | }; |
66 | |
67 | /** |
68 | * struct scmi_msg_hdr - Message(Tx/Rx) header |
69 | * |
70 | * @id: The identifier of the message being sent |
71 | * @protocol_id: The identifier of the protocol used to send @id message |
72 | * @type: The SCMI type for this message |
73 | * @seq: The token to identify the message. When a message returns, the |
74 | * platform returns the whole message header unmodified including the |
75 | * token |
76 | * @status: Status of the transfer once it's complete |
77 | * @poll_completion: Indicate if the transfer needs to be polled for |
78 | * completion or interrupt mode is used |
79 | */ |
80 | struct scmi_msg_hdr { |
81 | u8 id; |
82 | u8 protocol_id; |
83 | u8 type; |
84 | u16 seq; |
85 | u32 status; |
86 | bool poll_completion; |
87 | }; |
88 | |
89 | /** |
90 | * struct scmi_xfer - Structure representing a message flow |
91 | * |
92 | * @transfer_id: Unique ID for debug & profiling purpose |
93 | * @hdr: Transmit message header |
94 | * @tx: Transmit message |
95 | * @rx: Receive message, the buffer should be pre-allocated to store |
96 | * message. If request-ACK protocol is used, we can reuse the same |
97 | * buffer for the rx path as we use for the tx path. |
98 | * @done: command message transmit completion event |
99 | * @async_done: pointer to delayed response message received event completion |
100 | * @pending: True for xfers added to @pending_xfers hashtable |
101 | * @node: An hlist_node reference used to store this xfer, alternatively, on |
102 | * the free list @free_xfers or in the @pending_xfers hashtable |
103 | * @users: A refcount to track the active users for this xfer. |
104 | * This is meant to protect against the possibility that, when a command |
105 | * transaction times out concurrently with the reception of a valid |
106 | * response message, the xfer could be finally put on the TX path, and |
107 | * so vanish, while on the RX path scmi_rx_callback() is still |
108 | * processing it: in such a case this refcounting will ensure that, even |
109 | * though the timed-out transaction will anyway cause the command |
110 | * request to be reported as failed by time-out, the underlying xfer |
111 | * cannot be discarded and possibly reused until the last one user on |
112 | * the RX path has released it. |
113 | * @busy: An atomic flag to ensure exclusive write access to this xfer |
114 | * @state: The current state of this transfer, with states transitions deemed |
115 | * valid being: |
116 | * - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ] |
117 | * - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK |
118 | * (Missing synchronous response is assumed OK and ignored) |
119 | * @flags: Optional flags associated to this xfer. |
120 | * @lock: A spinlock to protect state and busy fields. |
121 | * @priv: A pointer for transport private usage. |
122 | */ |
123 | struct scmi_xfer { |
124 | int transfer_id; |
125 | struct scmi_msg_hdr hdr; |
126 | struct scmi_msg tx; |
127 | struct scmi_msg rx; |
128 | struct completion done; |
129 | struct completion *async_done; |
130 | bool pending; |
131 | struct hlist_node node; |
132 | refcount_t users; |
133 | #define SCMI_XFER_FREE 0 |
134 | #define SCMI_XFER_BUSY 1 |
135 | atomic_t busy; |
136 | #define SCMI_XFER_SENT_OK 0 |
137 | #define SCMI_XFER_RESP_OK 1 |
138 | #define SCMI_XFER_DRESP_OK 2 |
139 | int state; |
140 | #define SCMI_XFER_FLAG_IS_RAW BIT(0) |
141 | #define SCMI_XFER_IS_RAW(x) ((x)->flags & SCMI_XFER_FLAG_IS_RAW) |
142 | #define SCMI_XFER_FLAG_CHAN_SET BIT(1) |
143 | #define SCMI_XFER_IS_CHAN_SET(x) \ |
144 | ((x)->flags & SCMI_XFER_FLAG_CHAN_SET) |
145 | int flags; |
146 | /* A lock to protect state and busy fields */ |
147 | spinlock_t lock; |
148 | void *priv; |
149 | }; |
150 | |
151 | struct scmi_xfer_ops; |
152 | struct scmi_proto_helpers_ops; |
153 | |
154 | /** |
155 | * struct scmi_protocol_handle - Reference to an initialized protocol instance |
156 | * |
157 | * @dev: A reference to the associated SCMI instance device (handle->dev). |
158 | * @xops: A reference to a struct holding refs to the core xfer operations that |
159 | * can be used by the protocol implementation to generate SCMI messages. |
160 | * @set_priv: A method to set protocol private data for this instance. |
161 | * @get_priv: A method to get protocol private data previously set. |
162 | * |
163 | * This structure represents a protocol initialized against specific SCMI |
164 | * instance and it will be used as follows: |
165 | * - as a parameter fed from the core to the protocol initialization code so |
166 | * that it can access the core xfer operations to build and generate SCMI |
167 | * messages exclusively for the specific underlying protocol instance. |
168 | * - as an opaque handle fed by an SCMI driver user when it tries to access |
169 | * this protocol through its own protocol operations. |
170 | * In this case this handle will be returned as an opaque object together |
171 | * with the related protocol operations when the SCMI driver tries to access |
172 | * the protocol. |
173 | */ |
174 | struct scmi_protocol_handle { |
175 | struct device *dev; |
176 | const struct scmi_xfer_ops *xops; |
177 | const struct scmi_proto_helpers_ops *hops; |
178 | int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv, |
179 | u32 version); |
180 | void *(*get_priv)(const struct scmi_protocol_handle *ph); |
181 | }; |
182 | |
183 | /** |
184 | * struct scmi_iterator_state - Iterator current state descriptor |
185 | * @desc_index: Starting index for the current mulit-part request. |
186 | * @num_returned: Number of returned items in the last multi-part reply. |
187 | * @num_remaining: Number of remaining items in the multi-part message. |
188 | * @max_resources: Maximum acceptable number of items, configured by the caller |
189 | * depending on the underlying resources that it is querying. |
190 | * @loop_idx: The iterator loop index in the current multi-part reply. |
191 | * @rx_len: Size in bytes of the currenly processed message; it can be used by |
192 | * the user of the iterator to verify a reply size. |
193 | * @priv: Optional pointer to some additional state-related private data setup |
194 | * by the caller during the iterations. |
195 | */ |
196 | struct scmi_iterator_state { |
197 | unsigned int desc_index; |
198 | unsigned int num_returned; |
199 | unsigned int num_remaining; |
200 | unsigned int max_resources; |
201 | unsigned int loop_idx; |
202 | size_t rx_len; |
203 | void *priv; |
204 | }; |
205 | |
206 | /** |
207 | * struct scmi_iterator_ops - Custom iterator operations |
208 | * @prepare_message: An operation to provide the custom logic to fill in the |
209 | * SCMI command request pointed by @message. @desc_index is |
210 | * a reference to the next index to use in the multi-part |
211 | * request. |
212 | * @update_state: An operation to provide the custom logic to update the |
213 | * iterator state from the actual message response. |
214 | * @process_response: An operation to provide the custom logic needed to process |
215 | * each chunk of the multi-part message. |
216 | */ |
217 | struct scmi_iterator_ops { |
218 | void (*prepare_message)(void *message, unsigned int desc_index, |
219 | const void *priv); |
220 | int (*update_state)(struct scmi_iterator_state *st, |
221 | const void *response, void *priv); |
222 | int (*process_response)(const struct scmi_protocol_handle *ph, |
223 | const void *response, |
224 | struct scmi_iterator_state *st, void *priv); |
225 | }; |
226 | |
227 | struct scmi_fc_db_info { |
228 | int width; |
229 | u64 set; |
230 | u64 mask; |
231 | void __iomem *addr; |
232 | }; |
233 | |
234 | struct scmi_fc_info { |
235 | void __iomem *set_addr; |
236 | void __iomem *get_addr; |
237 | struct scmi_fc_db_info *set_db; |
238 | u32 rate_limit; |
239 | }; |
240 | |
241 | /** |
242 | * struct scmi_proto_helpers_ops - References to common protocol helpers |
243 | * @extended_name_get: A common helper function to retrieve extended naming |
244 | * for the specified resource using the specified command. |
245 | * Result is returned as a NULL terminated string in the |
246 | * pre-allocated area pointed to by @name with maximum |
247 | * capacity of @len bytes. |
248 | * @iter_response_init: A common helper to initialize a generic iterator to |
249 | * parse multi-message responses: when run the iterator |
250 | * will take care to send the initial command request as |
251 | * specified by @msg_id and @tx_size and then to parse the |
252 | * multi-part responses using the custom operations |
253 | * provided in @ops. |
254 | * @iter_response_run: A common helper to trigger the run of a previously |
255 | * initialized iterator. |
256 | * @protocol_msg_check: A common helper to check is a specific protocol message |
257 | * is supported. |
258 | * @fastchannel_init: A common helper used to initialize FC descriptors by |
259 | * gathering FC descriptions from the SCMI platform server. |
260 | * @fastchannel_db_ring: A common helper to ring a FC doorbell. |
261 | */ |
262 | struct scmi_proto_helpers_ops { |
263 | int (*extended_name_get)(const struct scmi_protocol_handle *ph, |
264 | u8 cmd_id, u32 res_id, u32 *flags, char *name, |
265 | size_t len); |
266 | void *(*iter_response_init)(const struct scmi_protocol_handle *ph, |
267 | struct scmi_iterator_ops *ops, |
268 | unsigned int max_resources, u8 msg_id, |
269 | size_t tx_size, void *priv); |
270 | int (*iter_response_run)(void *iter); |
271 | int (*protocol_msg_check)(const struct scmi_protocol_handle *ph, |
272 | u32 message_id, u32 *attributes); |
273 | void (*fastchannel_init)(const struct scmi_protocol_handle *ph, |
274 | u8 describe_id, u32 message_id, |
275 | u32 valid_size, u32 domain, |
276 | void __iomem **p_addr, |
277 | struct scmi_fc_db_info **p_db, |
278 | u32 *rate_limit); |
279 | void (*fastchannel_db_ring)(struct scmi_fc_db_info *db); |
280 | }; |
281 | |
282 | /** |
283 | * struct scmi_xfer_ops - References to the core SCMI xfer operations. |
284 | * @version_get: Get this version protocol. |
285 | * @xfer_get_init: Initialize one struct xfer if any xfer slot is free. |
286 | * @reset_rx_to_maxsz: Reset rx size to max transport size. |
287 | * @do_xfer: Do the SCMI transfer. |
288 | * @do_xfer_with_response: Do the SCMI transfer waiting for a response. |
289 | * @xfer_put: Free the xfer slot. |
290 | * |
291 | * Note that all this operations expect a protocol handle as first parameter; |
292 | * they then internally use it to infer the underlying protocol number: this |
293 | * way is not possible for a protocol implementation to forge messages for |
294 | * another protocol. |
295 | */ |
296 | struct scmi_xfer_ops { |
297 | int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version); |
298 | int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id, |
299 | size_t tx_size, size_t rx_size, |
300 | struct scmi_xfer **p); |
301 | void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph, |
302 | struct scmi_xfer *xfer); |
303 | int (*do_xfer)(const struct scmi_protocol_handle *ph, |
304 | struct scmi_xfer *xfer); |
305 | int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph, |
306 | struct scmi_xfer *xfer); |
307 | void (*xfer_put)(const struct scmi_protocol_handle *ph, |
308 | struct scmi_xfer *xfer); |
309 | }; |
310 | |
311 | typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *); |
312 | |
313 | /** |
314 | * struct scmi_protocol - Protocol descriptor |
315 | * @id: Protocol ID. |
316 | * @owner: Module reference if any. |
317 | * @instance_init: Mandatory protocol initialization function. |
318 | * @instance_deinit: Optional protocol de-initialization function. |
319 | * @ops: Optional reference to the operations provided by the protocol and |
320 | * exposed in scmi_protocol.h. |
321 | * @events: An optional reference to the events supported by this protocol. |
322 | * @supported_version: The highest version currently supported for this |
323 | * protocol by the agent. Each protocol implementation |
324 | * in the agent is supposed to downgrade to match the |
325 | * protocol version supported by the platform. |
326 | */ |
327 | struct scmi_protocol { |
328 | const u8 id; |
329 | struct module *owner; |
330 | const scmi_prot_init_ph_fn_t instance_init; |
331 | const scmi_prot_init_ph_fn_t instance_deinit; |
332 | const void *ops; |
333 | const struct scmi_protocol_events *events; |
334 | unsigned int supported_version; |
335 | }; |
336 | |
337 | #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \ |
338 | static const struct scmi_protocol *__this_proto = &(proto); \ |
339 | \ |
340 | int __init scmi_##name##_register(void) \ |
341 | { \ |
342 | return scmi_protocol_register(__this_proto); \ |
343 | } \ |
344 | \ |
345 | void __exit scmi_##name##_unregister(void) \ |
346 | { \ |
347 | scmi_protocol_unregister(__this_proto); \ |
348 | } |
349 | |
350 | #define DECLARE_SCMI_REGISTER_UNREGISTER(func) \ |
351 | int __init scmi_##func##_register(void); \ |
352 | void __exit scmi_##func##_unregister(void) |
353 | DECLARE_SCMI_REGISTER_UNREGISTER(base); |
354 | DECLARE_SCMI_REGISTER_UNREGISTER(clock); |
355 | DECLARE_SCMI_REGISTER_UNREGISTER(perf); |
356 | DECLARE_SCMI_REGISTER_UNREGISTER(power); |
357 | DECLARE_SCMI_REGISTER_UNREGISTER(reset); |
358 | DECLARE_SCMI_REGISTER_UNREGISTER(sensors); |
359 | DECLARE_SCMI_REGISTER_UNREGISTER(voltage); |
360 | DECLARE_SCMI_REGISTER_UNREGISTER(system); |
361 | DECLARE_SCMI_REGISTER_UNREGISTER(powercap); |
362 | |
363 | #endif /* _SCMI_PROTOCOLS_H */ |
364 | |