// SPDX-License-Identifier: GPL-2.0 /* * System Control and Management Interface (SCMI) Message Protocol driver * * SCMI Message Protocol is used between the System Control Processor(SCP) * and the Application Processors(AP). The Message Handling Unit(MHU) * provides a mechanism for inter-processor communication between SCP's * Cortex M3 and AP. * * SCP offers control and management of the core/cluster power states, * various power domain DVFS including the core/cluster, certain system * clocks configuration, thermal sensors and many others. * * Copyright (C) 2018-2024 ARM Ltd. */ #define pr_fmt(fmt) … #include <linux/bitmap.h> #include <linux/debugfs.h> #include <linux/device.h> #include <linux/export.h> #include <linux/idr.h> #include <linux/io.h> #include <linux/io-64-nonatomic-hi-lo.h> #include <linux/kernel.h> #include <linux/ktime.h> #include <linux/hashtable.h> #include <linux/list.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/processor.h> #include <linux/refcount.h> #include <linux/slab.h> #include <linux/xarray.h> #include "common.h" #include "notify.h" #include "raw_mode.h" #define CREATE_TRACE_POINTS #include <trace/events/scmi.h> static DEFINE_IDA(scmi_id); static DEFINE_XARRAY(scmi_protocols); /* List of all SCMI devices active in system */ static LIST_HEAD(scmi_list); /* Protection for the entire list */ static DEFINE_MUTEX(scmi_list_mutex); /* Track the unique id for the transfers for debug & profiling purpose */ static atomic_t transfer_last_id; static struct dentry *scmi_top_dentry; /** * struct scmi_xfers_info - Structure to manage transfer information * * @xfer_alloc_table: Bitmap table for allocated messages. * Index of this bitmap table is also used for message * sequence identifier. * @xfer_lock: Protection for message allocation * @max_msg: Maximum number of messages that can be pending * @free_xfers: A free list for available to use xfers. It is initialized with * a number of xfers equal to the maximum allowed in-flight * messages. * @pending_xfers: An hashtable, indexed by msg_hdr.seq, used to keep all the * currently in-flight messages. */ struct scmi_xfers_info { … }; /** * struct scmi_protocol_instance - Describe an initialized protocol instance. * @handle: Reference to the SCMI handle associated to this protocol instance. * @proto: A reference to the protocol descriptor. * @gid: A reference for per-protocol devres management. * @users: A refcount to track effective users of this protocol. * @priv: Reference for optional protocol private data. * @version: Protocol version supported by the platform as detected at runtime. * @negotiated_version: When the platform supports a newer protocol version, * the agent will try to negotiate with the platform the * usage of the newest version known to it, since * backward compatibility is NOT automatically assured. * This field is NON-zero when a successful negotiation * has completed. * @ph: An embedded protocol handle that will be passed down to protocol * initialization code to identify this instance. * * Each protocol is initialized independently once for each SCMI platform in * which is defined by DT and implemented by the SCMI server fw. */ struct scmi_protocol_instance { … }; #define ph_to_pi(h) … /** * struct scmi_debug_info - Debug common info * @top_dentry: A reference to the top debugfs dentry * @name: Name of this SCMI instance * @type: Type of this SCMI instance * @is_atomic: Flag to state if the transport of this instance is atomic * @counters: An array of atomic_c's used for tracking statistics (if enabled) */ struct scmi_debug_info { … }; /** * struct scmi_info - Structure representing a SCMI instance * * @id: A sequence number starting from zero identifying this instance * @dev: Device pointer * @desc: SoC description for this instance * @version: SCMI revision information containing protocol version, * implementation version and (sub-)vendor identification. * @handle: Instance of SCMI handle to send to clients * @tx_minfo: Universal Transmit Message management info * @rx_minfo: Universal Receive Message management info * @tx_idr: IDR object to map protocol id to Tx channel info pointer * @rx_idr: IDR object to map protocol id to Rx channel info pointer * @protocols: IDR for protocols' instance descriptors initialized for * this SCMI instance: populated on protocol's first attempted * usage. * @protocols_mtx: A mutex to protect protocols instances initialization. * @protocols_imp: List of protocols implemented, currently maximum of * scmi_revision_info.num_protocols elements allocated by the * base protocol * @active_protocols: IDR storing device_nodes for protocols actually defined * in the DT and confirmed as implemented by fw. * @atomic_threshold: Optional system wide DT-configured threshold, expressed * in microseconds, for atomic operations. * Only SCMI synchronous commands reported by the platform * to have an execution latency lesser-equal to the threshold * should be considered for atomic mode operation: such * decision is finally left up to the SCMI drivers. * @notify_priv: Pointer to private data structure specific to notifications. * @node: List head * @users: Number of users of this instance * @bus_nb: A notifier to listen for device bind/unbind on the scmi bus * @dev_req_nb: A notifier to listen for device request/unrequest on the scmi * bus * @devreq_mtx: A mutex to serialize device creation for this SCMI instance * @dbg: A pointer to debugfs related data (if any) * @raw: An opaque reference handle used by SCMI Raw mode. */ struct scmi_info { … }; #define handle_to_scmi_info(h) … #define bus_nb_to_scmi_info(nb) … #define req_nb_to_scmi_info(nb) … static void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv); static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr, enum scmi_bad_msg err); static struct scmi_transport_core_operations scmi_trans_core_ops = …; static unsigned long scmi_vendor_protocol_signature(unsigned int protocol_id, char *vendor_id, char *sub_vendor_id, u32 impl_ver) { … } static unsigned long scmi_protocol_key_calculate(int protocol_id, char *vendor_id, char *sub_vendor_id, u32 impl_ver) { … } static const struct scmi_protocol * __scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, char *sub_vendor_id, u32 impl_ver) { … } static const struct scmi_protocol * scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, char *sub_vendor_id, u32 impl_ver) { … } static const struct scmi_protocol * scmi_protocol_get(int protocol_id, struct scmi_revision_info *version) { … } static void scmi_protocol_put(const struct scmi_protocol *proto) { … } static int scmi_vendor_protocol_check(const struct scmi_protocol *proto) { … } int scmi_protocol_register(const struct scmi_protocol *proto) { … } EXPORT_SYMBOL_GPL(…); void scmi_protocol_unregister(const struct scmi_protocol *proto) { … } EXPORT_SYMBOL_GPL(…); /** * scmi_create_protocol_devices - Create devices for all pending requests for * this SCMI instance. * * @np: The device node describing the protocol * @info: The SCMI instance descriptor * @prot_id: The protocol ID * @name: The optional name of the device to be created: if not provided this * call will lead to the creation of all the devices currently requested * for the specified protocol. */ static void scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info, int prot_id, const char *name) { … } static void scmi_destroy_protocol_devices(struct scmi_info *info, int prot_id, const char *name) { … } void scmi_notification_instance_data_set(const struct scmi_handle *handle, void *priv) { … } void *scmi_notification_instance_data_get(const struct scmi_handle *handle) { … } /** * scmi_xfer_token_set - Reserve and set new token for the xfer at hand * * @minfo: Pointer to Tx/Rx Message management info based on channel type * @xfer: The xfer to act upon * * Pick the next unused monotonically increasing token and set it into * xfer->hdr.seq: picking a monotonically increasing value avoids immediate * reuse of freshly completed or timed-out xfers, thus mitigating the risk * of incorrect association of a late and expired xfer with a live in-flight * transaction, both happening to re-use the same token identifier. * * Since platform is NOT required to answer our request in-order we should * account for a few rare but possible scenarios: * * - exactly 'next_token' may be NOT available so pick xfer_id >= next_token * using find_next_zero_bit() starting from candidate next_token bit * * - all tokens ahead upto (MSG_TOKEN_ID_MASK - 1) are used in-flight but we * are plenty of free tokens at start, so try a second pass using * find_next_zero_bit() and starting from 0. * * X = used in-flight * * Normal * ------ * * |- xfer_id picked * -----------+---------------------------------------------------------- * | | |X|X|X| | | | | | ... ... ... ... ... ... ... ... ... ... ...|X|X| * ---------------------------------------------------------------------- * ^ * |- next_token * * Out-of-order pending at start * ----------------------------- * * |- xfer_id picked, last_token fixed * -----+---------------------------------------------------------------- * |X|X| | | | |X|X| ... ... ... ... ... ... ... ... ... ... ... ...|X| | * ---------------------------------------------------------------------- * ^ * |- next_token * * * Out-of-order pending at end * --------------------------- * * |- xfer_id picked, last_token fixed * -----+---------------------------------------------------------------- * |X|X| | | | |X|X| ... ... ... ... ... ... ... ... ... ... |X|X|X||X|X| * ---------------------------------------------------------------------- * ^ * |- next_token * * Context: Assumes to be called with @xfer_lock already acquired. * * Return: 0 on Success or error */ static int scmi_xfer_token_set(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) { … } /** * scmi_xfer_token_clear - Release the token * * @minfo: Pointer to Tx/Rx Message management info based on channel type * @xfer: The xfer to act upon */ static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) { … } /** * scmi_xfer_inflight_register_unlocked - Register the xfer as in-flight * * @xfer: The xfer to register * @minfo: Pointer to Tx/Rx Message management info based on channel type * * Note that this helper assumes that the xfer to be registered as in-flight * had been built using an xfer sequence number which still corresponds to a * free slot in the xfer_alloc_table. * * Context: Assumes to be called with @xfer_lock already acquired. */ static inline void scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer, struct scmi_xfers_info *minfo) { … } /** * scmi_xfer_inflight_register - Try to register an xfer as in-flight * * @xfer: The xfer to register * @minfo: Pointer to Tx/Rx Message management info based on channel type * * Note that this helper does NOT assume anything about the sequence number * that was baked into the provided xfer, so it checks at first if it can * be mapped to a free slot and fails with an error if another xfer with the * same sequence number is currently still registered as in-flight. * * Return: 0 on Success or -EBUSY if sequence number embedded in the xfer * could not rbe mapped to a free slot in the xfer_alloc_table. */ static int scmi_xfer_inflight_register(struct scmi_xfer *xfer, struct scmi_xfers_info *minfo) { … } /** * scmi_xfer_raw_inflight_register - An helper to register the given xfer as in * flight on the TX channel, if possible. * * @handle: Pointer to SCMI entity handle * @xfer: The xfer to register * * Return: 0 on Success, error otherwise */ int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle, struct scmi_xfer *xfer) { … } /** * scmi_xfer_pending_set - Pick a proper sequence number and mark the xfer * as pending in-flight * * @xfer: The xfer to act upon * @minfo: Pointer to Tx/Rx Message management info based on channel type * * Return: 0 on Success or error otherwise */ static inline int scmi_xfer_pending_set(struct scmi_xfer *xfer, struct scmi_xfers_info *minfo) { … } /** * scmi_xfer_get() - Allocate one message * * @handle: Pointer to SCMI entity handle * @minfo: Pointer to Tx/Rx Message management info based on channel type * * Helper function which is used by various message functions that are * exposed to clients of this driver for allocating a message traffic event. * * Picks an xfer from the free list @free_xfers (if any available) and perform * a basic initialization. * * Note that, at this point, still no sequence number is assigned to the * allocated xfer, nor it is registered as a pending transaction. * * The successfully initialized xfer is refcounted. * * Context: Holds @xfer_lock while manipulating @free_xfers. * * Return: An initialized xfer if all went fine, else pointer error. */ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle, struct scmi_xfers_info *minfo) { … } /** * scmi_xfer_raw_get - Helper to get a bare free xfer from the TX channel * * @handle: Pointer to SCMI entity handle * * Note that xfer is taken from the TX channel structures. * * Return: A valid xfer on Success, or an error-pointer otherwise */ struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle) { … } /** * scmi_xfer_raw_channel_get - Helper to get a reference to the proper channel * to use for a specific protocol_id Raw transaction. * * @handle: Pointer to SCMI entity handle * @protocol_id: Identifier of the protocol * * Note that in a regular SCMI stack, usually, a protocol has to be defined in * the DT to have an associated channel and be usable; but in Raw mode any * protocol in range is allowed, re-using the Base channel, so as to enable * fuzzing on any protocol without the need of a fully compiled DT. * * Return: A reference to the channel to use, or an ERR_PTR */ struct scmi_chan_info * scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id) { … } /** * __scmi_xfer_put() - Release a message * * @minfo: Pointer to Tx/Rx Message management info based on channel type * @xfer: message that was reserved by scmi_xfer_get * * After refcount check, possibly release an xfer, clearing the token slot, * removing xfer from @pending_xfers and putting it back into free_xfers. * * This holds a spinlock to maintain integrity of internal data structures. */ static void __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer) { … } /** * scmi_xfer_raw_put - Release an xfer that was taken by @scmi_xfer_raw_get * * @handle: Pointer to SCMI entity handle * @xfer: A reference to the xfer to put * * Note that as with other xfer_put() handlers the xfer is really effectively * released only if there are no more users on the system. */ void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) { … } /** * scmi_xfer_lookup_unlocked - Helper to lookup an xfer_id * * @minfo: Pointer to Tx/Rx Message management info based on channel type * @xfer_id: Token ID to lookup in @pending_xfers * * Refcounting is untouched. * * Context: Assumes to be called with @xfer_lock already acquired. * * Return: A valid xfer on Success or error otherwise */ static struct scmi_xfer * scmi_xfer_lookup_unlocked(struct scmi_xfers_info *minfo, u16 xfer_id) { … } /** * scmi_bad_message_trace - A helper to trace weird messages * * @cinfo: A reference to the channel descriptor on which the message was * received * @msg_hdr: Message header to track * @err: A specific error code used as a status value in traces. * * This helper can be used to trace any kind of weird, incomplete, unexpected, * timed-out message that arrives and as such, can be traced only referring to * the header content, since the payload is missing/unreliable. */ static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr, enum scmi_bad_msg err) { … } /** * scmi_msg_response_validate - Validate message type against state of related * xfer * * @cinfo: A reference to the channel descriptor. * @msg_type: Message type to check * @xfer: A reference to the xfer to validate against @msg_type * * This function checks if @msg_type is congruent with the current state of * a pending @xfer; if an asynchronous delayed response is received before the * related synchronous response (Out-of-Order Delayed Response) the missing * synchronous response is assumed to be OK and completed, carrying on with the * Delayed Response: this is done to address the case in which the underlying * SCMI transport can deliver such out-of-order responses. * * Context: Assumes to be called with xfer->lock already acquired. * * Return: 0 on Success, error otherwise */ static inline int scmi_msg_response_validate(struct scmi_chan_info *cinfo, u8 msg_type, struct scmi_xfer *xfer) { … } /** * scmi_xfer_state_update - Update xfer state * * @xfer: A reference to the xfer to update * @msg_type: Type of message being processed. * * Note that this message is assumed to have been already successfully validated * by @scmi_msg_response_validate(), so here we just update the state. * * Context: Assumes to be called on an xfer exclusively acquired using the * busy flag. */ static inline void scmi_xfer_state_update(struct scmi_xfer *xfer, u8 msg_type) { … } static bool scmi_xfer_acquired(struct scmi_xfer *xfer) { … } /** * scmi_xfer_command_acquire - Helper to lookup and acquire a command xfer * * @cinfo: A reference to the channel descriptor. * @msg_hdr: A message header to use as lookup key * * When a valid xfer is found for the sequence number embedded in the provided * msg_hdr, reference counting is properly updated and exclusive access to this * xfer is granted till released with @scmi_xfer_command_release. * * Return: A valid @xfer on Success or error otherwise. */ static inline struct scmi_xfer * scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr) { … } static inline void scmi_xfer_command_release(struct scmi_info *info, struct scmi_xfer *xfer) { … } static inline void scmi_clear_channel(struct scmi_info *info, struct scmi_chan_info *cinfo) { … } static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { … } static void scmi_handle_response(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { … } /** * scmi_rx_callback() - callback for receiving messages * * @cinfo: SCMI channel info * @msg_hdr: Message header * @priv: Transport specific private data. * * Processes one received message to appropriate transfer information and * signals completion of the transfer. * * NOTE: This function will be invoked in IRQ context, hence should be * as optimal as possible. */ static void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { … } /** * xfer_put() - Release a transmit message * * @ph: Pointer to SCMI protocol handle * @xfer: message that was reserved by xfer_get_init */ static void xfer_put(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer) { … } static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, ktime_t stop) { … } static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc, struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, unsigned int timeout_ms) { … } /** * scmi_wait_for_message_response - An helper to group all the possible ways of * waiting for a synchronous message response. * * @cinfo: SCMI channel info * @xfer: Reference to the transfer being waited for. * * Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on * configuration flags like xfer->hdr.poll_completion. * * Return: 0 on Success, error otherwise. */ static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer) { … } /** * scmi_xfer_raw_wait_for_message_response - An helper to wait for a message * reply to an xfer raw request on a specific channel for the required timeout. * * @cinfo: SCMI channel info * @xfer: Reference to the transfer being waited for. * @timeout_ms: The maximum timeout in milliseconds * * Return: 0 on Success, error otherwise. */ int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, unsigned int timeout_ms) { … } /** * do_xfer() - Do one transfer * * @ph: Pointer to SCMI protocol handle * @xfer: Transfer to initiate and wait for response * * Return: -ETIMEDOUT in case of no response, if transmit error, * return corresponding error, else if all goes well, * return 0. */ static int do_xfer(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer) { … } static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer) { … } /** * do_xfer_with_response() - Do one transfer and wait until the delayed * response is received * * @ph: Pointer to SCMI protocol handle * @xfer: Transfer to initiate and wait for response * * Using asynchronous commands in atomic/polling mode should be avoided since * it could cause long busy-waiting here, so ignore polling for the delayed * response and WARN if it was requested for this command transaction since * upper layers should refrain from issuing such kind of requests. * * The only other option would have been to refrain from using any asynchronous * command even if made available, when an atomic transport is detected, and * instead forcibly use the synchronous version (thing that can be easily * attained at the protocol layer), but this would also have led to longer * stalls of the channel for synchronous commands and possibly timeouts. * (in other words there is usually a good reason if a platform provides an * asynchronous version of a command and we should prefer to use it...just not * when using atomic/polling mode) * * Return: -ETIMEDOUT in case of no delayed response, if transmit error, * return corresponding error, else if all goes well, return 0. */ static int do_xfer_with_response(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer) { … } /** * xfer_get_init() - Allocate and initialise one message for transmit * * @ph: Pointer to SCMI protocol handle * @msg_id: Message identifier * @tx_size: transmit message size * @rx_size: receive message size * @p: pointer to the allocated and initialised message * * This function allocates the message using @scmi_xfer_get and * initialise the header. * * Return: 0 if all went fine with @p pointing to message, else * corresponding error. */ static 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) { … } /** * version_get() - command to get the revision of the SCMI entity * * @ph: Pointer to SCMI protocol handle * @version: Holds returned version of protocol. * * Updates the SCMI information in the internal data structure. * * Return: 0 if all went fine, else return appropriate error. */ static int version_get(const struct scmi_protocol_handle *ph, u32 *version) { … } /** * scmi_set_protocol_priv - Set protocol specific data at init time * * @ph: A reference to the protocol handle. * @priv: The private data to set. * @version: The detected protocol version for the core to register. * * Return: 0 on Success */ static int scmi_set_protocol_priv(const struct scmi_protocol_handle *ph, void *priv, u32 version) { … } /** * scmi_get_protocol_priv - Set protocol specific data at init time * * @ph: A reference to the protocol handle. * * Return: Protocol private data if any was set. */ static void *scmi_get_protocol_priv(const struct scmi_protocol_handle *ph) { … } static const struct scmi_xfer_ops xfer_ops = …; struct scmi_msg_resp_domain_name_get { … }; /** * scmi_common_extended_name_get - Common helper to get extended resources name * @ph: A protocol handle reference. * @cmd_id: The specific command ID to use. * @res_id: The specific resource ID to use. * @flags: A pointer to specific flags to use, if any. * @name: A pointer to the preallocated area where the retrieved name will be * stored as a NULL terminated string. * @len: The len in bytes of the @name char array. * * Return: 0 on Succcess */ static int scmi_common_extended_name_get(const struct scmi_protocol_handle *ph, u8 cmd_id, u32 res_id, u32 *flags, char *name, size_t len) { … } /** * scmi_common_get_max_msg_size - Get maximum message size * @ph: A protocol handle reference. * * Return: Maximum message size for the current protocol. */ static int scmi_common_get_max_msg_size(const struct scmi_protocol_handle *ph) { … } /** * struct scmi_iterator - Iterator descriptor * @msg: A reference to the message TX buffer; filled by @prepare_message with * a proper custom command payload for each multi-part command request. * @resp: A reference to the response RX buffer; used by @update_state and * @process_response to parse the multi-part replies. * @t: A reference to the underlying xfer initialized and used transparently by * the iterator internal routines. * @ph: A reference to the associated protocol handle to be used. * @ops: A reference to the custom provided iterator operations. * @state: The current iterator state; used and updated in turn by the iterators * internal routines and by the caller-provided @scmi_iterator_ops. * @priv: A reference to optional private data as provided by the caller and * passed back to the @@scmi_iterator_ops. */ struct scmi_iterator { … }; static void *scmi_iterator_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) { … } static int scmi_iterator_run(void *iter) { … } struct scmi_msg_get_fc_info { … }; struct scmi_msg_resp_desc_fc { … }; static void scmi_common_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, u32 *rate_limit) { … } #define SCMI_PROTO_FC_RING_DB(w) … static void scmi_common_fastchannel_db_ring(struct scmi_fc_db_info *db) { … } /** * scmi_protocol_msg_check - Check protocol message attributes * * @ph: A reference to the protocol handle. * @message_id: The ID of the message to check. * @attributes: A parameter to optionally return the retrieved message * attributes, in case of Success. * * An helper to check protocol message attributes for a specific protocol * and message pair. * * Return: 0 on SUCCESS */ static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph, u32 message_id, u32 *attributes) { … } static const struct scmi_proto_helpers_ops helpers_ops = …; /** * scmi_revision_area_get - Retrieve version memory area. * * @ph: A reference to the protocol handle. * * A helper to grab the version memory area reference during SCMI Base protocol * initialization. * * Return: A reference to the version memory area associated to the SCMI * instance underlying this protocol handle. */ struct scmi_revision_info * scmi_revision_area_get(const struct scmi_protocol_handle *ph) { … } /** * scmi_protocol_version_negotiate - Negotiate protocol version * * @ph: A reference to the protocol handle. * * An helper to negotiate a protocol version different from the latest * advertised as supported from the platform: on Success backward * compatibility is assured by the platform. * * Return: 0 on Success */ static int scmi_protocol_version_negotiate(struct scmi_protocol_handle *ph) { … } /** * scmi_alloc_init_protocol_instance - Allocate and initialize a protocol * instance descriptor. * @info: The reference to the related SCMI instance. * @proto: The protocol descriptor. * * Allocate a new protocol instance descriptor, using the provided @proto * description, against the specified SCMI instance @info, and initialize it; * all resources management is handled via a dedicated per-protocol devres * group. * * Context: Assumes to be called with @protocols_mtx already acquired. * Return: A reference to a freshly allocated and initialized protocol instance * or ERR_PTR on failure. On failure the @proto reference is at first * put using @scmi_protocol_put() before releasing all the devres group. */ static struct scmi_protocol_instance * scmi_alloc_init_protocol_instance(struct scmi_info *info, const struct scmi_protocol *proto) { … } /** * scmi_get_protocol_instance - Protocol initialization helper. * @handle: A reference to the SCMI platform instance. * @protocol_id: The protocol being requested. * * In case the required protocol has never been requested before for this * instance, allocate and initialize all the needed structures while handling * resource allocation with a dedicated per-protocol devres subgroup. * * Return: A reference to an initialized protocol instance or error on failure: * in particular returns -EPROBE_DEFER when the desired protocol could * NOT be found. */ static struct scmi_protocol_instance * __must_check scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id) { … } /** * scmi_protocol_acquire - Protocol acquire * @handle: A reference to the SCMI platform instance. * @protocol_id: The protocol being requested. * * Register a new user for the requested protocol on the specified SCMI * platform instance, possibly triggering its initialization on first user. * * Return: 0 if protocol was acquired successfully. */ int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id) { … } /** * scmi_protocol_release - Protocol de-initialization helper. * @handle: A reference to the SCMI platform instance. * @protocol_id: The protocol being requested. * * Remove one user for the specified protocol and triggers de-initialization * and resources de-allocation once the last user has gone. */ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) { … } void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, u8 *prot_imp) { … } static bool scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) { … } struct scmi_protocol_devres { … }; static void scmi_devm_release_protocol(struct device *dev, void *res) { … } static struct scmi_protocol_instance __must_check * scmi_devres_protocol_instance_get(struct scmi_device *sdev, u8 protocol_id) { … } /** * scmi_devm_protocol_get - Devres managed get protocol operations and handle * @sdev: A reference to an scmi_device whose embedded struct device is to * be used for devres accounting. * @protocol_id: The protocol being requested. * @ph: A pointer reference used to pass back the associated protocol handle. * * Get hold of a protocol accounting for its usage, eventually triggering its * initialization, and returning the protocol specific operations and related * protocol handle which will be used as first argument in most of the * protocols operations methods. * Being a devres based managed method, protocol hold will be automatically * released, and possibly de-initialized on last user, once the SCMI driver * owning the scmi_device is unbound from it. * * Return: A reference to the requested protocol operations or error. * Must be checked for errors by caller. */ static const void __must_check * scmi_devm_protocol_get(struct scmi_device *sdev, u8 protocol_id, struct scmi_protocol_handle **ph) { … } /** * scmi_devm_protocol_acquire - Devres managed helper to get hold of a protocol * @sdev: A reference to an scmi_device whose embedded struct device is to * be used for devres accounting. * @protocol_id: The protocol being requested. * * Get hold of a protocol accounting for its usage, possibly triggering its * initialization but without getting access to its protocol specific operations * and handle. * * Being a devres based managed method, protocol hold will be automatically * released, and possibly de-initialized on last user, once the SCMI driver * owning the scmi_device is unbound from it. * * Return: 0 on SUCCESS */ static int __must_check scmi_devm_protocol_acquire(struct scmi_device *sdev, u8 protocol_id) { … } static int scmi_devm_protocol_match(struct device *dev, void *res, void *data) { … } /** * scmi_devm_protocol_put - Devres managed put protocol operations and handle * @sdev: A reference to an scmi_device whose embedded struct device is to * be used for devres accounting. * @protocol_id: The protocol being requested. * * Explicitly release a protocol hold previously obtained calling the above * @scmi_devm_protocol_get. */ static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id) { … } /** * scmi_is_transport_atomic - Method to check if underlying transport for an * SCMI instance is configured as atomic. * * @handle: A reference to the SCMI platform instance. * @atomic_threshold: An optional return value for the system wide currently * configured threshold for atomic operations. * * Return: True if transport is configured as atomic */ static bool scmi_is_transport_atomic(const struct scmi_handle *handle, unsigned int *atomic_threshold) { … } /** * scmi_handle_get() - Get the SCMI handle for a device * * @dev: pointer to device for which we want SCMI handle * * NOTE: The function does not track individual clients of the framework * and is expected to be maintained by caller of SCMI protocol library. * scmi_handle_put must be balanced with successful scmi_handle_get * * Return: pointer to handle if successful, NULL on error */ static struct scmi_handle *scmi_handle_get(struct device *dev) { … } /** * scmi_handle_put() - Release the handle acquired by scmi_handle_get * * @handle: handle acquired by scmi_handle_get * * NOTE: The function does not track individual clients of the framework * and is expected to be maintained by caller of SCMI protocol library. * scmi_handle_put must be balanced with successful scmi_handle_get * * Return: 0 is successfully released * if null was passed, it returns -EINVAL; */ static int scmi_handle_put(const struct scmi_handle *handle) { … } static void scmi_device_link_add(struct device *consumer, struct device *supplier) { … } static void scmi_set_handle(struct scmi_device *scmi_dev) { … } static int __scmi_xfer_info_init(struct scmi_info *sinfo, struct scmi_xfers_info *info) { … } static int scmi_channels_max_msg_configure(struct scmi_info *sinfo) { … } static int scmi_xfer_info_init(struct scmi_info *sinfo) { … } static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node, int prot_id, bool tx) { … } static inline int scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node, int prot_id) { … } /** * scmi_channels_setup - Helper to initialize all required channels * * @info: The SCMI instance descriptor. * * Initialize all the channels found described in the DT against the underlying * configured transport using custom defined dedicated devices instead of * borrowing devices from the SCMI drivers; this way channels are initialized * upfront during core SCMI stack probing and are no more coupled with SCMI * devices used by SCMI drivers. * * Note that, even though a pair of TX/RX channels is associated to each * protocol defined in the DT, a distinct freshly initialized channel is * created only if the DT node for the protocol at hand describes a dedicated * channel: in all the other cases the common BASE protocol channel is reused. * * Return: 0 on Success */ static int scmi_channels_setup(struct scmi_info *info) { … } static int scmi_chan_destroy(int id, void *p, void *idr) { … } static void scmi_cleanup_channels(struct scmi_info *info, struct idr *idr) { … } static void scmi_cleanup_txrx_channels(struct scmi_info *info) { … } static int scmi_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) { … } static int scmi_device_request_notifier(struct notifier_block *nb, unsigned long action, void *data) { … } static const char * const dbg_counter_strs[] = …; static ssize_t reset_all_on_write(struct file *filp, const char __user *buf, size_t count, loff_t *ppos) { … } static const struct file_operations fops_reset_counts = …; static void scmi_debugfs_counters_setup(struct scmi_debug_info *dbg, struct dentry *trans) { … } static void scmi_debugfs_common_cleanup(void *d) { … } static struct scmi_debug_info *scmi_debugfs_common_setup(struct scmi_info *info) { … } static int scmi_debugfs_raw_mode_setup(struct scmi_info *info) { … } static const struct scmi_desc *scmi_transport_setup(struct device *dev) { … } static int scmi_probe(struct platform_device *pdev) { … } static void scmi_remove(struct platform_device *pdev) { … } static ssize_t protocol_version_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static DEVICE_ATTR_RO(protocol_version); static ssize_t firmware_version_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static DEVICE_ATTR_RO(firmware_version); static ssize_t vendor_id_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static DEVICE_ATTR_RO(vendor_id); static ssize_t sub_vendor_id_show(struct device *dev, struct device_attribute *attr, char *buf) { … } static DEVICE_ATTR_RO(sub_vendor_id); static struct attribute *versions_attrs[] = …; ATTRIBUTE_GROUPS(…); static struct platform_driver scmi_driver = …; static struct dentry *scmi_debugfs_init(void) { … } static int __init scmi_driver_init(void) { … } module_init(…) …; static void __exit scmi_driver_exit(void) { … } module_exit(scmi_driver_exit); MODULE_ALIAS(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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