485 lines
18 KiB
C
485 lines
18 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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* driver 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) 2018-2021 ARM Ltd.
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*/
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#ifndef _SCMI_COMMON_H
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#define _SCMI_COMMON_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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#include "notify.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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#define MAX_PROTOCOLS_IMP 16
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#define MAX_OPPS 16
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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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#define MSG_ID_MASK GENMASK(7, 0)
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#define MSG_XTRACT_ID(hdr) FIELD_GET(MSG_ID_MASK, (hdr))
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#define MSG_TYPE_MASK GENMASK(9, 8)
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#define MSG_XTRACT_TYPE(hdr) FIELD_GET(MSG_TYPE_MASK, (hdr))
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#define MSG_TYPE_COMMAND 0
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#define MSG_TYPE_DELAYED_RESP 2
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#define MSG_TYPE_NOTIFICATION 3
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#define MSG_PROTOCOL_ID_MASK GENMASK(17, 10)
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#define MSG_XTRACT_PROT_ID(hdr) FIELD_GET(MSG_PROTOCOL_ID_MASK, (hdr))
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#define MSG_TOKEN_ID_MASK GENMASK(27, 18)
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#define MSG_XTRACT_TOKEN(hdr) FIELD_GET(MSG_TOKEN_ID_MASK, (hdr))
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#define MSG_TOKEN_MAX (MSG_XTRACT_TOKEN(MSG_TOKEN_ID_MASK) + 1)
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/*
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* Size of @pending_xfers hashtable included in @scmi_xfers_info; ideally, in
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* order to minimize space and collisions, this should equal max_msg, i.e. the
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* maximum number of in-flight messages on a specific platform, but such value
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* is only available at runtime while kernel hashtables are statically sized:
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* pick instead as a fixed static size the maximum number of entries that can
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* fit the whole table into one 4k page.
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*/
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#define SCMI_PENDING_XFERS_HT_ORDER_SZ 9
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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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* pack_scmi_header() - packs and returns 32-bit header
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*
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* @hdr: pointer to header containing all the information on message id,
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* protocol id, sequence id and type.
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*
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* Return: 32-bit packed message header to be sent to the platform.
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*/
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static inline u32 pack_scmi_header(struct scmi_msg_hdr *hdr)
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{
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return FIELD_PREP(MSG_ID_MASK, hdr->id) |
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FIELD_PREP(MSG_TYPE_MASK, hdr->type) |
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FIELD_PREP(MSG_TOKEN_ID_MASK, hdr->seq) |
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FIELD_PREP(MSG_PROTOCOL_ID_MASK, hdr->protocol_id);
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}
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/**
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* unpack_scmi_header() - unpacks and records message and protocol id
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*
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* @msg_hdr: 32-bit packed message header sent from the platform
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* @hdr: pointer to header to fetch message and protocol id.
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*/
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static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
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{
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hdr->id = MSG_XTRACT_ID(msg_hdr);
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hdr->protocol_id = MSG_XTRACT_PROT_ID(msg_hdr);
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hdr->type = MSG_XTRACT_TYPE(msg_hdr);
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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_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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* @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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/* 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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/*
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* An helper macro to lookup an xfer from the @pending_xfers hashtable
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* using the message sequence number token as a key.
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*/
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#define XFER_FIND(__ht, __k) \
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({ \
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typeof(__k) k_ = __k; \
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struct scmi_xfer *xfer_ = NULL; \
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\
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hash_for_each_possible((__ht), xfer_, node, k_) \
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if (xfer_->hdr.seq == k_) \
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break; \
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xfer_; \
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})
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struct scmi_xfer_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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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_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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struct scmi_revision_info *
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scmi_revision_area_get(const struct scmi_protocol_handle *ph);
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int scmi_handle_put(const struct scmi_handle *handle);
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struct scmi_handle *scmi_handle_get(struct device *dev);
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void scmi_set_handle(struct scmi_device *scmi_dev);
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void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph,
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u8 *prot_imp);
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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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int __init scmi_bus_init(void);
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void __exit scmi_bus_exit(void);
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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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#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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const struct scmi_protocol *scmi_protocol_get(int protocol_id);
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void scmi_protocol_put(int protocol_id);
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int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id);
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void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id);
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/* SCMI Transport */
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/**
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* struct scmi_chan_info - Structure representing a SCMI channel information
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*
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* @dev: Reference to device in the SCMI hierarchy corresponding to this
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* channel
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* @handle: Pointer to SCMI entity handle
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* @no_completion_irq: Flag to indicate that this channel has no completion
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* interrupt mechanism for synchronous commands.
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* This can be dynamically set by transports at run-time
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* inside their provided .chan_setup().
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* @transport_info: Transport layer related information
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*/
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struct scmi_chan_info {
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struct device *dev;
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struct scmi_handle *handle;
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bool no_completion_irq;
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void *transport_info;
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};
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/**
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* struct scmi_transport_ops - Structure representing a SCMI transport ops
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*
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* @link_supplier: Optional callback to add link to a supplier device
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* @chan_available: Callback to check if channel is available or not
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* @chan_setup: Callback to allocate and setup a channel
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* @chan_free: Callback to free a channel
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* @get_max_msg: Optional callback to provide max_msg dynamically
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* Returns the maximum number of messages for the channel type
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* (tx or rx) that can be pending simultaneously in the system
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* @send_message: Callback to send a message
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* @mark_txdone: Callback to mark tx as done
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* @fetch_response: Callback to fetch response
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* @fetch_notification: Callback to fetch notification
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* @clear_channel: Callback to clear a channel
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* @poll_done: Callback to poll transfer status
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*/
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struct scmi_transport_ops {
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int (*link_supplier)(struct device *dev);
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bool (*chan_available)(struct device *dev, int idx);
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int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,
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bool tx);
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int (*chan_free)(int id, void *p, void *data);
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unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);
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int (*send_message)(struct scmi_chan_info *cinfo,
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struct scmi_xfer *xfer);
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void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret,
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struct scmi_xfer *xfer);
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void (*fetch_response)(struct scmi_chan_info *cinfo,
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struct scmi_xfer *xfer);
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void (*fetch_notification)(struct scmi_chan_info *cinfo,
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size_t max_len, struct scmi_xfer *xfer);
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void (*clear_channel)(struct scmi_chan_info *cinfo);
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bool (*poll_done)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
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};
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int scmi_protocol_device_request(const struct scmi_device_id *id_table);
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void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table);
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struct scmi_device *scmi_child_dev_find(struct device *parent,
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int prot_id, const char *name);
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/**
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* struct scmi_desc - Description of SoC integration
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*
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* @transport_init: An optional function that a transport can provide to
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* initialize some transport-specific setup during SCMI core
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* initialization, so ahead of SCMI core probing.
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* @transport_exit: An optional function that a transport can provide to
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* de-initialize some transport-specific setup during SCMI core
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* de-initialization, so after SCMI core removal.
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* @ops: Pointer to the transport specific ops structure
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* @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
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* @max_msg: Maximum number of messages for a channel type (tx or rx) that can
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* be pending simultaneously in the system. May be overridden by the
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* get_max_msg op.
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* @max_msg_size: Maximum size of data per message that can be handled.
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* @force_polling: Flag to force this whole transport to use SCMI core polling
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* mechanism instead of completion interrupts even if available.
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* @sync_cmds_completed_on_ret: Flag to indicate that the transport assures
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* synchronous-command messages are atomically
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* completed on .send_message: no need to poll
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* actively waiting for a response.
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* Used by core internally only when polling is
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* selected as a waiting for reply method: i.e.
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* if a completion irq was found use that anyway.
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* @atomic_enabled: Flag to indicate that this transport, which is assured not
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* to sleep anywhere on the TX path, can be used in atomic mode
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* when requested.
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*/
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struct scmi_desc {
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int (*transport_init)(void);
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void (*transport_exit)(void);
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const struct scmi_transport_ops *ops;
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int max_rx_timeout_ms;
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int max_msg;
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int max_msg_size;
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const bool force_polling;
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const bool sync_cmds_completed_on_ret;
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const bool atomic_enabled;
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};
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#ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX
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extern const struct scmi_desc scmi_mailbox_desc;
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#endif
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#ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC
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extern const struct scmi_desc scmi_smc_desc;
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#endif
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#ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO
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extern const struct scmi_desc scmi_virtio_desc;
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#endif
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#ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE
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extern const struct scmi_desc scmi_optee_desc;
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#endif
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void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv);
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void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
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/* shmem related declarations */
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struct scmi_shared_mem;
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void shmem_tx_prepare(struct scmi_shared_mem __iomem *shmem,
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struct scmi_xfer *xfer);
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u32 shmem_read_header(struct scmi_shared_mem __iomem *shmem);
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void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem,
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struct scmi_xfer *xfer);
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void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem,
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size_t max_len, struct scmi_xfer *xfer);
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void shmem_clear_channel(struct scmi_shared_mem __iomem *shmem);
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bool shmem_poll_done(struct scmi_shared_mem __iomem *shmem,
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struct scmi_xfer *xfer);
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/* declarations for message passing transports */
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struct scmi_msg_payld;
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/* Maximum overhead of message w.r.t. struct scmi_desc.max_msg_size */
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#define SCMI_MSG_MAX_PROT_OVERHEAD (2 * sizeof(__le32))
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size_t msg_response_size(struct scmi_xfer *xfer);
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size_t msg_command_size(struct scmi_xfer *xfer);
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void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer);
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u32 msg_read_header(struct scmi_msg_payld *msg);
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void msg_fetch_response(struct scmi_msg_payld *msg, size_t len,
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struct scmi_xfer *xfer);
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void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,
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size_t max_len, struct scmi_xfer *xfer);
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void scmi_notification_instance_data_set(const struct scmi_handle *handle,
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void *priv);
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void *scmi_notification_instance_data_get(const struct scmi_handle *handle);
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#endif /* _SCMI_COMMON_H */
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