/* SPDX-License-Identifier: GPL-2.0 */ /* * System Control and Management Interface (SCMI) Message Protocol * protocols common header file containing some definitions, structures * and function prototypes used in all the different SCMI protocols. * * Copyright (C) 2022 ARM Ltd. */ #ifndef _SCMI_PROTOCOLS_H #define _SCMI_PROTOCOLS_H #include <linux/bitfield.h> #include <linux/completion.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/hashtable.h> #include <linux/list.h> #include <linux/module.h> #include <linux/refcount.h> #include <linux/scmi_protocol.h> #include <linux/spinlock.h> #include <linux/types.h> #include <linux/unaligned.h> #define PROTOCOL_REV_MINOR_MASK GENMASK(15, 0) #define PROTOCOL_REV_MAJOR_MASK GENMASK(31, 16) #define PROTOCOL_REV_MAJOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))) #define PROTOCOL_REV_MINOR(x) ((u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))) #define SCMI_PROTOCOL_VENDOR_BASE 0x80 #define MSG_SUPPORTS_FASTCHANNEL(x) ((x) & BIT(0)) enum scmi_common_cmd { PROTOCOL_VERSION = 0x0, PROTOCOL_ATTRIBUTES = 0x1, PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, NEGOTIATE_PROTOCOL_VERSION = 0x10, }; /** * struct scmi_msg_resp_prot_version - Response for a message * * @minor_version: Minor version of the ABI that firmware supports * @major_version: Major version of the ABI that firmware supports * * In general, ABI version changes follow the rule that minor version increments * are backward compatible. Major revision changes in ABI may not be * backward compatible. * * Response to a generic message with message type SCMI_MSG_VERSION */ struct scmi_msg_resp_prot_version { __le16 minor_version; __le16 major_version; }; /** * struct scmi_msg - Message(Tx/Rx) structure * * @buf: Buffer pointer * @len: Length of data in the Buffer */ struct scmi_msg { void *buf; size_t len; }; /** * struct scmi_msg_hdr - Message(Tx/Rx) header * * @id: The identifier of the message being sent * @protocol_id: The identifier of the protocol used to send @id message * @type: The SCMI type for this message * @seq: The token to identify the message. When a message returns, the * platform returns the whole message header unmodified including the * token * @status: Status of the transfer once it's complete * @poll_completion: Indicate if the transfer needs to be polled for * completion or interrupt mode is used */ struct scmi_msg_hdr { u8 id; u8 protocol_id; u8 type; u16 seq; u32 status; bool poll_completion; }; /** * struct scmi_xfer - Structure representing a message flow * * @transfer_id: Unique ID for debug & profiling purpose * @hdr: Transmit message header * @tx: Transmit message * @rx: Receive message, the buffer should be pre-allocated to store * message. If request-ACK protocol is used, we can reuse the same * buffer for the rx path as we use for the tx path. * @done: command message transmit completion event * @async_done: pointer to delayed response message received event completion * @pending: True for xfers added to @pending_xfers hashtable * @node: An hlist_node reference used to store this xfer, alternatively, on * the free list @free_xfers or in the @pending_xfers hashtable * @users: A refcount to track the active users for this xfer. * This is meant to protect against the possibility that, when a command * transaction times out concurrently with the reception of a valid * response message, the xfer could be finally put on the TX path, and * so vanish, while on the RX path scmi_rx_callback() is still * processing it: in such a case this refcounting will ensure that, even * though the timed-out transaction will anyway cause the command * request to be reported as failed by time-out, the underlying xfer * cannot be discarded and possibly reused until the last one user on * the RX path has released it. * @busy: An atomic flag to ensure exclusive write access to this xfer * @state: The current state of this transfer, with states transitions deemed * valid being: * - SCMI_XFER_SENT_OK -> SCMI_XFER_RESP_OK [ -> SCMI_XFER_DRESP_OK ] * - SCMI_XFER_SENT_OK -> SCMI_XFER_DRESP_OK * (Missing synchronous response is assumed OK and ignored) * @flags: Optional flags associated to this xfer. * @lock: A spinlock to protect state and busy fields. * @priv: A pointer for transport private usage. */ struct scmi_xfer { int transfer_id; struct scmi_msg_hdr hdr; struct scmi_msg tx; struct scmi_msg rx; struct completion done; struct completion *async_done; bool pending; struct hlist_node node; refcount_t users; #define SCMI_XFER_FREE 0 #define SCMI_XFER_BUSY 1 atomic_t busy; #define SCMI_XFER_SENT_OK 0 #define SCMI_XFER_RESP_OK 1 #define SCMI_XFER_DRESP_OK 2 int state; #define SCMI_XFER_FLAG_IS_RAW BIT(0) #define SCMI_XFER_IS_RAW(x) ((x)->flags & SCMI_XFER_FLAG_IS_RAW) #define SCMI_XFER_FLAG_CHAN_SET BIT(1) #define SCMI_XFER_IS_CHAN_SET(x) \ ((x)->flags & SCMI_XFER_FLAG_CHAN_SET) int flags; /* A lock to protect state and busy fields */ spinlock_t lock; void *priv; }; struct scmi_xfer_ops; struct scmi_proto_helpers_ops; /** * struct scmi_protocol_handle - Reference to an initialized protocol instance * * @dev: A reference to the associated SCMI instance device (handle->dev). * @version: The protocol version currently effectively in use by this * initialized instance of the protocol as determined at the end of * any possibly needed negotiations performed by the core. * @xops: A reference to a struct holding refs to the core xfer operations that * can be used by the protocol implementation to generate SCMI messages. * @set_priv: A method to set protocol private data for this instance. * @get_priv: A method to get protocol private data previously set. * * This structure represents a protocol initialized against specific SCMI * instance and it will be used as follows: * - as a parameter fed from the core to the protocol initialization code so * that it can access the core xfer operations to build and generate SCMI * messages exclusively for the specific underlying protocol instance. * - as an opaque handle fed by an SCMI driver user when it tries to access * this protocol through its own protocol operations. * In this case this handle will be returned as an opaque object together * with the related protocol operations when the SCMI driver tries to access * the protocol. */ struct scmi_protocol_handle { struct device *dev; unsigned int version; const struct scmi_xfer_ops *xops; const struct scmi_proto_helpers_ops *hops; int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv); void *(*get_priv)(const struct scmi_protocol_handle *ph); }; /** * struct scmi_iterator_state - Iterator current state descriptor * @desc_index: Starting index for the current multi-part request. * @num_returned: Number of returned items in the last multi-part reply. * @num_remaining: Number of remaining items in the multi-part message. * @max_resources: Maximum acceptable number of items, configured by the caller * depending on the underlying resources that it is querying. * @loop_idx: The iterator loop index in the current multi-part reply. * @rx_len: Size in bytes of the currently processed message; it can be used by * the user of the iterator to verify a reply size. * @priv: Optional pointer to some additional state-related private data setup * by the caller during the iterations. */ struct scmi_iterator_state { unsigned int desc_index; unsigned int num_returned; unsigned int num_remaining; unsigned int max_resources; unsigned int loop_idx; size_t rx_len; void *priv; }; /** * struct scmi_iterator_ops - Custom iterator operations * @prepare_message: An operation to provide the custom logic to fill in the * SCMI command request pointed by @message. @desc_index is * a reference to the next index to use in the multi-part * request. * @update_state: An operation to provide the custom logic to update the * iterator state from the actual message response. * @process_response: An operation to provide the custom logic needed to process * each chunk of the multi-part message. */ struct scmi_iterator_ops { void (*prepare_message)(void *message, unsigned int desc_index, const void *priv); int (*update_state)(struct scmi_iterator_state *st, const void *response, void *priv); int (*process_response)(const struct scmi_protocol_handle *ph, const void *response, struct scmi_iterator_state *st, void *priv); }; struct scmi_fc_db_info { int width; u64 set; u64 mask; void __iomem *addr; }; struct scmi_fc_info { void __iomem *set_addr; void __iomem *get_addr; struct scmi_fc_db_info *set_db; u32 rate_limit; }; /** * struct scmi_proto_helpers_ops - References to common protocol helpers * @extended_name_get: A common helper function to retrieve extended naming * for the specified resource using the specified command. * Result is returned as a NULL terminated string in the * pre-allocated area pointed to by @name with maximum * capacity of @len bytes. * @iter_response_init: A common helper to initialize a generic iterator to * parse multi-message responses: when run the iterator * will take care to send the initial command request as * specified by @msg_id and @tx_size and then to parse the * multi-part responses using the custom operations * provided in @ops. * @iter_response_run: A common helper to trigger the run of a previously * initialized iterator. * @protocol_msg_check: A common helper to check is a specific protocol message * is supported. * @fastchannel_init: A common helper used to initialize FC descriptors by * gathering FC descriptions from the SCMI platform server. * @fastchannel_db_ring: A common helper to ring a FC doorbell. * @get_max_msg_size: A common helper to get the maximum message size. */ struct scmi_proto_helpers_ops { int (*extended_name_get)(const struct scmi_protocol_handle *ph, u8 cmd_id, u32 res_id, u32 *flags, char *name, size_t len); void *(*iter_response_init)(const struct scmi_protocol_handle *ph, struct scmi_iterator_ops *ops, unsigned int max_resources, u8 msg_id, size_t tx_size, void *priv); int (*iter_response_run)(void *iter); int (*protocol_msg_check)(const struct scmi_protocol_handle *ph, u32 message_id, u32 *attributes); void (*fastchannel_init)(const struct scmi_protocol_handle *ph, u8 describe_id, u32 message_id, u32 valid_size, u32 domain, void __iomem **p_addr, struct scmi_fc_db_info **p_db, u32 *rate_limit); void (*fastchannel_db_ring)(struct scmi_fc_db_info *db); int (*get_max_msg_size)(const struct scmi_protocol_handle *ph); }; /** * struct scmi_xfer_ops - References to the core SCMI xfer operations. * @xfer_get_init: Initialize one struct xfer if any xfer slot is free. * @reset_rx_to_maxsz: Reset rx size to max transport size. * @do_xfer: Do the SCMI transfer. * @do_xfer_with_response: Do the SCMI transfer waiting for a response. * @xfer_put: Free the xfer slot. * * Note that all this operations expect a protocol handle as first parameter; * they then internally use it to infer the underlying protocol number: this * way is not possible for a protocol implementation to forge messages for * another protocol. */ struct scmi_xfer_ops { int (*xfer_get_init)(const struct scmi_protocol_handle *ph, u8 msg_id, size_t tx_size, size_t rx_size, struct scmi_xfer **p); void (*reset_rx_to_maxsz)(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer); int (*do_xfer)(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer); int (*do_xfer_with_response)(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer); void (*xfer_put)(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer); }; typedef int (*scmi_prot_init_ph_fn_t)(const struct scmi_protocol_handle *); /** * struct scmi_protocol - Protocol descriptor * @id: Protocol ID. * @owner: Module reference if any. * @instance_init: Mandatory protocol initialization function. * @instance_deinit: Optional protocol de-initialization function. * @ops: Optional reference to the operations provided by the protocol and * exposed in scmi_protocol.h. * @events: An optional reference to the events supported by this protocol. * @supported_version: The highest version currently supported for this * protocol by the agent. Each protocol implementation * in the agent is supposed to downgrade to match the * protocol version supported by the platform. * @vendor_id: A firmware vendor string for vendor protocols matching. * Ignored when @id identifies a standard protocol, cannot be NULL * otherwise. * @sub_vendor_id: A firmware sub_vendor string for vendor protocols matching. * Ignored if NULL or when @id identifies a standard protocol. * @impl_ver: A firmware implementation version for vendor protocols matching. * Ignored if zero or if @id identifies a standard protocol. * * Note that vendor protocols matching at load time is performed by attempting * the closest match first against the tuple (vendor, sub_vendor, impl_ver) */ struct scmi_protocol { const u8 id; struct module *owner; const scmi_prot_init_ph_fn_t instance_init; const scmi_prot_init_ph_fn_t instance_deinit; const void *ops; const struct scmi_protocol_events *events; unsigned int supported_version; char *vendor_id; char *sub_vendor_id; u32 impl_ver; }; #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(name, proto) \ static const struct scmi_protocol *__this_proto = &(proto); \ \ int __init scmi_##name##_register(void) \ { \ return scmi_protocol_register(__this_proto); \ } \ \ void __exit scmi_##name##_unregister(void) \ { \ scmi_protocol_unregister(__this_proto); \ } #define DECLARE_SCMI_REGISTER_UNREGISTER(func) \ int __init scmi_##func##_register(void); \ void __exit scmi_##func##_unregister(void) DECLARE_SCMI_REGISTER_UNREGISTER(base); DECLARE_SCMI_REGISTER_UNREGISTER(clock); DECLARE_SCMI_REGISTER_UNREGISTER(perf); DECLARE_SCMI_REGISTER_UNREGISTER(pinctrl); DECLARE_SCMI_REGISTER_UNREGISTER(power); DECLARE_SCMI_REGISTER_UNREGISTER(reset); DECLARE_SCMI_REGISTER_UNREGISTER(sensors); DECLARE_SCMI_REGISTER_UNREGISTER(voltage); DECLARE_SCMI_REGISTER_UNREGISTER(system); DECLARE_SCMI_REGISTER_UNREGISTER(powercap); #endif /* _SCMI_PROTOCOLS_H */
