diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/protocols.h')
| -rw-r--r-- | drivers/firmware/arm_scmi/protocols.h | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h new file mode 100644 index 000000000..2f3bf691d --- /dev/null +++ b/drivers/firmware/arm_scmi/protocols.h @@ -0,0 +1,342 @@ +/* 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 */ |