/* SPDX-License-Identifier: GPL-2.0 */ /* * System Control and Management Interface (SCMI) Message Protocol * driver common header file containing some definitions, structures * and function prototypes used in all the different SCMI protocols. * * Copyright (C) 2018-2021 ARM Ltd. */ #ifndef _SCMI_COMMON_H #define _SCMI_COMMON_H #include #include #include #include #include #include #include #include #include #include #include #include #include #include "notify.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 MAX_PROTOCOLS_IMP 16 #define MAX_OPPS 16 enum scmi_common_cmd { PROTOCOL_VERSION = 0x0, PROTOCOL_ATTRIBUTES = 0x1, PROTOCOL_MESSAGE_ATTRIBUTES = 0x2, }; /** * 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; }; #define MSG_ID_MASK GENMASK(7, 0) #define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr)) #define MSG_TYPE_MASK GENMASK(9, 8) #define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr)) #define MSG_TYPE_COMMAND 0 #define MSG_TYPE_DELAYED_RESP 2 #define MSG_TYPE_NOTIFICATION 3 #define MSG_PROTOCOL_ID_MASK GENMASK(17, 10) #define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr)) #define MSG_TOKEN_ID_MASK GENMASK(27, 18) #define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr)) #define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1) /* * Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in * order to minimize space and collisions, this should equal max_msg, i.e. the * maximum number of in-flight messages on a specific platform, but such value * is only available at runtime while kernel hashtables are statically sized: * pick instead as a fixed static size the maximum number of entries that can * fit the whole table into one 4k page. */ #define SCMI_PENDING_XFERS_HT_ORDER_SZ 9 /** * 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; }; /** * pack_scmi_header() - packs and returns 32-bit header * * @hdr: pointer to header containing all the information on message id, * protocol id, sequence id and type. * * Return: 32-bit packed message header to be sent to the platform. */ static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr) { return FIELD_PREP(MSG_ID_MASK, hdr->id) | FIELD_PREP(MSG_TYPE_MASK, hdr->type) | FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) | FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id); } /** * unpack_scmi_header() - unpacks and records message and protocol id * * @msg_hdr: 32-bit packed message header sent from the platform * @hdr: pointer to header to fetch message and protocol id. */ static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr) { hdr->id = MSG_XTRACT_ID(msg_hdr); hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr); hdr->type = MSG_XTRACT_TYPE(msg_hdr); } /** * 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_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) * @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; /* A lock to protect state and busy fields */ spinlock_t lock; void *priv; }; /* * An helper macro to lookup an xfer from the @pending_xfers hashtable * using the message sequence number token as a key. */ #define XFER_FIND(__ht, __k) \ ({ \ typeof(__k) k_ = __k; \ struct scmi_xfer *xfer_ = NULL; \ \ hash_for_each_possible((__ht), xfer_, node, k_) \ if (xfer_->hdr.seq == k_) \ break; \ xfer_; \ }) struct scmi_xfer_ops; /** * struct scmi_protocol_handle - Reference to an initialized protocol instance * * @dev: A reference to the associated SCMI instance device (handle->dev). * @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; const struct scmi_xfer_ops *xops; int (*set_priv)(const struct scmi_protocol_handle *ph, void *priv); void *(*get_priv)(const struct scmi_protocol_handle *ph); }; /** * struct scmi_xfer_ops - References to the core SCMI xfer operations. * @version_get: Get this version protocol. * @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 (*version_get)(const struct scmi_protocol_handle *ph, u32 *version); 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); }; struct scmi_revision_info * scmi_revision_area_get(const struct scmi_protocol_handle *ph); int scmi_handle_put(const struct scmi_handle *handle); void scmi_device_link_add(struct device *consumer, struct device *supplier); struct scmi_handle *scmi_handle_get(struct device *dev); void scmi_set_handle(struct scmi_device *scmi_dev); void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, u8 *prot_imp); 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. */ 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; }; int __init scmi_bus_init(void); void __exit scmi_bus_exit(void); #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(power); DECLARE_SCMI_REGISTER_UNREGISTER(reset); DECLARE_SCMI_REGISTER_UNREGISTER(sensors); DECLARE_SCMI_REGISTER_UNREGISTER(voltage); DECLARE_SCMI_REGISTER_UNREGISTER(system); #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); \ } const struct scmi_protocol *scmi_protocol_get(int protocol_id); void scmi_protocol_put(int protocol_id); int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id); void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id); /* SCMI Transport */ /** * struct scmi_chan_info - Structure representing a SCMI channel information * * @dev: Reference to device in the SCMI hierarchy corresponding to this * channel * @handle: Pointer to SCMI entity handle * @transport_info: Transport layer related information */ struct scmi_chan_info { struct device *dev; struct scmi_handle *handle; void *transport_info; }; /** * struct scmi_transport_ops - Structure representing a SCMI transport ops * * @link_supplier: Optional callback to add link to a supplier device * @chan_available: Callback to check if channel is available or not * @chan_setup: Callback to allocate and setup a channel * @chan_free: Callback to free a channel * @get_max_msg: Optional callback to provide max_msg dynamically * Returns the maximum number of messages for the channel type * (tx or rx) that can be pending simultaneously in the system * @send_message: Callback to send a message * @mark_txdone: Callback to mark tx as done * @fetch_response: Callback to fetch response * @fetch_notification: Callback to fetch notification * @clear_channel: Callback to clear a channel * @poll_done: Callback to poll transfer status */ struct scmi_transport_ops { int (*link_supplier)(struct device *dev); bool (*chan_available)(struct device *dev, int idx); int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, bool tx); int (*chan_free)(int id, void *p, void *data); unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo); int (*send_message)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret); void (*fetch_response)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); void (*fetch_notification)(struct scmi_chan_info *cinfo, size_t max_len, struct scmi_xfer *xfer); void (*clear_channel)(struct scmi_chan_info *cinfo); bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer); }; int scmi_protocol_device_request(const struct scmi_device_id *id_table); void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table); struct scmi_device *scmi_child_dev_find(struct device *parent, int prot_id, const char *name); /** * struct scmi_desc - Description of SoC integration * * @transport_init: An optional function that a transport can provide to * initialize some transport-specific setup during SCMI core * initialization, so ahead of SCMI core probing. * @transport_exit: An optional function that a transport can provide to * de-initialize some transport-specific setup during SCMI core * de-initialization, so after SCMI core removal. * @ops: Pointer to the transport specific ops structure * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds) * @max_msg: Maximum number of messages for a channel type (tx or rx) that can * be pending simultaneously in the system. May be overridden by the * get_max_msg op. * @max_msg_size: Maximum size of data per message that can be handled. */ struct scmi_desc { int (*transport_init)(void); void (*transport_exit)(void); const struct scmi_transport_ops *ops; int max_rx_timeout_ms; int max_msg; int max_msg_size; }; #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX extern const struct scmi_desc scmi_mailbox_desc; #endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC extern const struct scmi_desc scmi_smc_desc; #endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO extern const struct scmi_desc scmi_virtio_desc; #endif void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id); /* shmem related declarations */ struct scmi_shared_mem; void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem, struct scmi_xfer *xfer); u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem); void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem, struct scmi_xfer *xfer); void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem, size_t max_len, struct scmi_xfer *xfer); void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem); bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem, struct scmi_xfer *xfer); /* declarations for message passing transports */ struct scmi_msg_payld; /* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */ #define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32)) size_t msg_response_size(struct scmi_xfer *xfer); size_t msg_command_size(struct scmi_xfer *xfer); void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer); u32 msg_read_header(struct scmi_msg_payld *msg); void msg_fetch_response(struct scmi_msg_payld *msg, size_t len, struct scmi_xfer *xfer); void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len, size_t max_len, struct scmi_xfer *xfer); void scmi_notification_instance_data_set(const struct scmi_handle *handle, void *priv); void *scmi_notification_instance_data_get(const struct scmi_handle *handle); #endif /* _SCMI_COMMON_H */