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