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1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * System Control and Management Interface (SCMI) Message Protocol4 * protocols common header file containing some definitions, structures5 * and function prototypes used in all the different SCMI protocols.6 *7 * Copyright (C) 2022 ARM Ltd.8 */9#ifndef _SCMI_PROTOCOLS_H10#define _SCMI_PROTOCOLS_H11 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 <linux/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#define SCMI_PROTOCOL_VENDOR_BASE 0x8033 34enum scmi_common_cmd {35 PROTOCOL_VERSION = 0x0,36 PROTOCOL_ATTRIBUTES = 0x1,37 PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,38 NEGOTIATE_PROTOCOL_VERSION = 0x10,39};40 41/**42 * struct scmi_msg_resp_prot_version - Response for a message43 *44 * @minor_version: Minor version of the ABI that firmware supports45 * @major_version: Major version of the ABI that firmware supports46 *47 * In general, ABI version changes follow the rule that minor version increments48 * are backward compatible. Major revision changes in ABI may not be49 * backward compatible.50 *51 * Response to a generic message with message type SCMI_MSG_VERSION52 */53struct scmi_msg_resp_prot_version {54 __le16 minor_version;55 __le16 major_version;56};57 58/**59 * struct scmi_msg - Message(Tx/Rx) structure60 *61 * @buf: Buffer pointer62 * @len: Length of data in the Buffer63 */64struct scmi_msg {65 void *buf;66 size_t len;67};68 69/**70 * struct scmi_msg_hdr - Message(Tx/Rx) header71 *72 * @id: The identifier of the message being sent73 * @protocol_id: The identifier of the protocol used to send @id message74 * @type: The SCMI type for this message75 * @seq: The token to identify the message. When a message returns, the76 * platform returns the whole message header unmodified including the77 * token78 * @status: Status of the transfer once it's complete79 * @poll_completion: Indicate if the transfer needs to be polled for80 * completion or interrupt mode is used81 */82struct scmi_msg_hdr {83 u8 id;84 u8 protocol_id;85 u8 type;86 u16 seq;87 u32 status;88 bool poll_completion;89};90 91/**92 * struct scmi_xfer - Structure representing a message flow93 *94 * @transfer_id: Unique ID for debug & profiling purpose95 * @hdr: Transmit message header96 * @tx: Transmit message97 * @rx: Receive message, the buffer should be pre-allocated to store98 * message. If request-ACK protocol is used, we can reuse the same99 * buffer for the rx path as we use for the tx path.100 * @done: command message transmit completion event101 * @async_done: pointer to delayed response message received event completion102 * @pending: True for xfers added to @pending_xfers hashtable103 * @node: An hlist_node reference used to store this xfer, alternatively, on104 * the free list @free_xfers or in the @pending_xfers hashtable105 * @users: A refcount to track the active users for this xfer.106 * This is meant to protect against the possibility that, when a command107 * transaction times out concurrently with the reception of a valid108 * response message, the xfer could be finally put on the TX path, and109 * so vanish, while on the RX path scmi_rx_callback() is still110 * processing it: in such a case this refcounting will ensure that, even111 * though the timed-out transaction will anyway cause the command112 * request to be reported as failed by time-out, the underlying xfer113 * cannot be discarded and possibly reused until the last one user on114 * the RX path has released it.115 * @busy: An atomic flag to ensure exclusive write access to this xfer116 * @state: The current state of this transfer, with states transitions deemed117 * valid being:118 * - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ]119 * - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK120 * (Missing synchronous response is assumed OK and ignored)121 * @flags: Optional flags associated to this xfer.122 * @lock: A spinlock to protect state and busy fields.123 * @priv: A pointer for transport private usage.124 */125struct scmi_xfer {126 int transfer_id;127 struct scmi_msg_hdr hdr;128 struct scmi_msg tx;129 struct scmi_msg rx;130 struct completion done;131 struct completion *async_done;132 bool pending;133 struct hlist_node node;134 refcount_t users;135#define SCMI_XFER_FREE 0136#define SCMI_XFER_BUSY 1137 atomic_t busy;138#define SCMI_XFER_SENT_OK 0139#define SCMI_XFER_RESP_OK 1140#define SCMI_XFER_DRESP_OK 2141 int state;142#define SCMI_XFER_FLAG_IS_RAW BIT(0)143#define SCMI_XFER_IS_RAW(x) ((x)->flags & SCMI_XFER_FLAG_IS_RAW)144#define SCMI_XFER_FLAG_CHAN_SET BIT(1)145#define SCMI_XFER_IS_CHAN_SET(x) \146 ((x)->flags & SCMI_XFER_FLAG_CHAN_SET)147 int flags;148 /* A lock to protect state and busy fields */149 spinlock_t lock;150 void *priv;151};152 153struct scmi_xfer_ops;154struct scmi_proto_helpers_ops;155 156/**157 * struct scmi_protocol_handle - Reference to an initialized protocol instance158 *159 * @dev: A reference to the associated SCMI instance device (handle->dev).160 * @xops: A reference to a struct holding refs to the core xfer operations that161 * can be used by the protocol implementation to generate SCMI messages.162 * @set_priv: A method to set protocol private data for this instance.163 * @get_priv: A method to get protocol private data previously set.164 *165 * This structure represents a protocol initialized against specific SCMI166 * instance and it will be used as follows:167 * - as a parameter fed from the core to the protocol initialization code so168 * that it can access the core xfer operations to build and generate SCMI169 * messages exclusively for the specific underlying protocol instance.170 * - as an opaque handle fed by an SCMI driver user when it tries to access171 * this protocol through its own protocol operations.172 * In this case this handle will be returned as an opaque object together173 * with the related protocol operations when the SCMI driver tries to access174 * the protocol.175 */176struct scmi_protocol_handle {177 struct device *dev;178 const struct scmi_xfer_ops *xops;179 const struct scmi_proto_helpers_ops *hops;180 int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv,181 u32 version);182 void *(*get_priv)(const struct scmi_protocol_handle *ph);183};184 185/**186 * struct scmi_iterator_state - Iterator current state descriptor187 * @desc_index: Starting index for the current mulit-part request.188 * @num_returned: Number of returned items in the last multi-part reply.189 * @num_remaining: Number of remaining items in the multi-part message.190 * @max_resources: Maximum acceptable number of items, configured by the caller191 * depending on the underlying resources that it is querying.192 * @loop_idx: The iterator loop index in the current multi-part reply.193 * @rx_len: Size in bytes of the currenly processed message; it can be used by194 * the user of the iterator to verify a reply size.195 * @priv: Optional pointer to some additional state-related private data setup196 * by the caller during the iterations.197 */198struct scmi_iterator_state {199 unsigned int desc_index;200 unsigned int num_returned;201 unsigned int num_remaining;202 unsigned int max_resources;203 unsigned int loop_idx;204 size_t rx_len;205 void *priv;206};207 208/**209 * struct scmi_iterator_ops - Custom iterator operations210 * @prepare_message: An operation to provide the custom logic to fill in the211 * SCMI command request pointed by @message. @desc_index is212 * a reference to the next index to use in the multi-part213 * request.214 * @update_state: An operation to provide the custom logic to update the215 * iterator state from the actual message response.216 * @process_response: An operation to provide the custom logic needed to process217 * each chunk of the multi-part message.218 */219struct scmi_iterator_ops {220 void (*prepare_message)(void *message, unsigned int desc_index,221 const void *priv);222 int (*update_state)(struct scmi_iterator_state *st,223 const void *response, void *priv);224 int (*process_response)(const struct scmi_protocol_handle *ph,225 const void *response,226 struct scmi_iterator_state *st, void *priv);227};228 229struct scmi_fc_db_info {230 int width;231 u64 set;232 u64 mask;233 void __iomem *addr;234};235 236struct scmi_fc_info {237 void __iomem *set_addr;238 void __iomem *get_addr;239 struct scmi_fc_db_info *set_db;240 u32 rate_limit;241};242 243/**244 * struct scmi_proto_helpers_ops - References to common protocol helpers245 * @extended_name_get: A common helper function to retrieve extended naming246 * for the specified resource using the specified command.247 * Result is returned as a NULL terminated string in the248 * pre-allocated area pointed to by @name with maximum249 * capacity of @len bytes.250 * @iter_response_init: A common helper to initialize a generic iterator to251 * parse multi-message responses: when run the iterator252 * will take care to send the initial command request as253 * specified by @msg_id and @tx_size and then to parse the254 * multi-part responses using the custom operations255 * provided in @ops.256 * @iter_response_run: A common helper to trigger the run of a previously257 * initialized iterator.258 * @protocol_msg_check: A common helper to check is a specific protocol message259 * is supported.260 * @fastchannel_init: A common helper used to initialize FC descriptors by261 * gathering FC descriptions from the SCMI platform server.262 * @fastchannel_db_ring: A common helper to ring a FC doorbell.263 * @get_max_msg_size: A common helper to get the maximum message size.264 */265struct scmi_proto_helpers_ops {266 int (*extended_name_get)(const struct scmi_protocol_handle *ph,267 u8 cmd_id, u32 res_id, u32 *flags, char *name,268 size_t len);269 void *(*iter_response_init)(const struct scmi_protocol_handle *ph,270 struct scmi_iterator_ops *ops,271 unsigned int max_resources, u8 msg_id,272 size_t tx_size, void *priv);273 int (*iter_response_run)(void *iter);274 int (*protocol_msg_check)(const struct scmi_protocol_handle *ph,275 u32 message_id, u32 *attributes);276 void (*fastchannel_init)(const struct scmi_protocol_handle *ph,277 u8 describe_id, u32 message_id,278 u32 valid_size, u32 domain,279 void __iomem **p_addr,280 struct scmi_fc_db_info **p_db,281 u32 *rate_limit);282 void (*fastchannel_db_ring)(struct scmi_fc_db_info *db);283 int (*get_max_msg_size)(const struct scmi_protocol_handle *ph);284};285 286/**287 * struct scmi_xfer_ops - References to the core SCMI xfer operations.288 * @version_get: Get this version protocol.289 * @xfer_get_init: Initialize one struct xfer if any xfer slot is free.290 * @reset_rx_to_maxsz: Reset rx size to max transport size.291 * @do_xfer: Do the SCMI transfer.292 * @do_xfer_with_response: Do the SCMI transfer waiting for a response.293 * @xfer_put: Free the xfer slot.294 *295 * Note that all this operations expect a protocol handle as first parameter;296 * they then internally use it to infer the underlying protocol number: this297 * way is not possible for a protocol implementation to forge messages for298 * another protocol.299 */300struct scmi_xfer_ops {301 int (*version_get)(const struct scmi_protocol_handle *ph, u32 *version);302 int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id,303 size_t tx_size, size_t rx_size,304 struct scmi_xfer **p);305 void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph,306 struct scmi_xfer *xfer);307 int (*do_xfer)(const struct scmi_protocol_handle *ph,308 struct scmi_xfer *xfer);309 int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph,310 struct scmi_xfer *xfer);311 void (*xfer_put)(const struct scmi_protocol_handle *ph,312 struct scmi_xfer *xfer);313};314 315typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *);316 317/**318 * struct scmi_protocol - Protocol descriptor319 * @id: Protocol ID.320 * @owner: Module reference if any.321 * @instance_init: Mandatory protocol initialization function.322 * @instance_deinit: Optional protocol de-initialization function.323 * @ops: Optional reference to the operations provided by the protocol and324 * exposed in scmi_protocol.h.325 * @events: An optional reference to the events supported by this protocol.326 * @supported_version: The highest version currently supported for this327 * protocol by the agent. Each protocol implementation328 * in the agent is supposed to downgrade to match the329 * protocol version supported by the platform.330 * @vendor_id: A firmware vendor string for vendor protocols matching.331 * Ignored when @id identifies a standard protocol, cannot be NULL332 * otherwise.333 * @sub_vendor_id: A firmware sub_vendor string for vendor protocols matching.334 * Ignored if NULL or when @id identifies a standard protocol.335 * @impl_ver: A firmware implementation version for vendor protocols matching.336 * Ignored if zero or if @id identifies a standard protocol.337 *338 * Note that vendor protocols matching at load time is performed by attempting339 * the closest match first against the tuple (vendor, sub_vendor, impl_ver)340 */341struct scmi_protocol {342 const u8 id;343 struct module *owner;344 const scmi_prot_init_ph_fn_t instance_init;345 const scmi_prot_init_ph_fn_t instance_deinit;346 const void *ops;347 const struct scmi_protocol_events *events;348 unsigned int supported_version;349 char *vendor_id;350 char *sub_vendor_id;351 u32 impl_ver;352};353 354#define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \355static const struct scmi_protocol *__this_proto = &(proto); \356 \357int __init scmi_##name##_register(void) \358{ \359 return scmi_protocol_register(__this_proto); \360} \361 \362void __exit scmi_##name##_unregister(void) \363{ \364 scmi_protocol_unregister(__this_proto); \365}366 367#define DECLARE_SCMI_REGISTER_UNREGISTER(func) \368 int __init scmi_##func##_register(void); \369 void __exit scmi_##func##_unregister(void)370DECLARE_SCMI_REGISTER_UNREGISTER(base);371DECLARE_SCMI_REGISTER_UNREGISTER(clock);372DECLARE_SCMI_REGISTER_UNREGISTER(perf);373DECLARE_SCMI_REGISTER_UNREGISTER(pinctrl);374DECLARE_SCMI_REGISTER_UNREGISTER(power);375DECLARE_SCMI_REGISTER_UNREGISTER(reset);376DECLARE_SCMI_REGISTER_UNREGISTER(sensors);377DECLARE_SCMI_REGISTER_UNREGISTER(voltage);378DECLARE_SCMI_REGISTER_UNREGISTER(system);379DECLARE_SCMI_REGISTER_UNREGISTER(powercap);380 381#endif /* _SCMI_PROTOCOLS_H */382