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diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h
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+/* 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 <asm/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))))
+
+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;
+};
+
+/**
+ * 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)
+ * @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;
+};
+
+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).
+ * @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;
+ 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 mulit-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 currenly 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;
+};
+
+/**
+ * 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.
+ * @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.
+ */
+struct scmi_proto_helpers_ops {
+ int (*extended_name_get)(const struct scmi_protocol_handle *ph,
+ u8 cmd_id, u32 res_id, 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);
+ 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);
+ void (*fastchannel_db_ring)(struct scmi_fc_db_info *db);
+};
+
+/**
+ * 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);
+};
+
+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;
+};
+
+#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(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 */