| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Cristian Marussi | 7541 | 67.20% | 81 | 66.39% |
| Sudeep Holla | 3110 | 27.71% | 28 | 22.95% |
| Igor Skalkin | 182 | 1.62% | 2 | 1.64% |
| Lukasz Luba | 158 | 1.41% | 1 | 0.82% |
| Viresh Kumar | 117 | 1.04% | 1 | 0.82% |
| Rishabh Bhatnagar | 27 | 0.24% | 1 | 0.82% |
| Peter Hilber | 25 | 0.22% | 1 | 0.82% |
| Peng Fan | 25 | 0.22% | 1 | 0.82% |
| Etienne Carriere | 18 | 0.16% | 1 | 0.82% |
| Aditya Pakki | 10 | 0.09% | 1 | 0.82% |
| Nikunj Kela | 5 | 0.04% | 1 | 0.82% |
| Dan Carpenter | 2 | 0.02% | 1 | 0.82% |
| Alyssa Ross | 1 | 0.01% | 1 | 0.82% |
| Christophe Jaillet | 1 | 0.01% | 1 | 0.82% |
| Total | 11222 | 122 |
// 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) 2018-2021 ARM Ltd. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " 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_address.h> #include <linux/of_device.h> #include <linux/processor.h> #include <linux/refcount.h> #include <linux/slab.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_IDR(scmi_protocols); static DEFINE_SPINLOCK(protocol_lock); /* 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 { unsigned long *xfer_alloc_table; spinlock_t xfer_lock; int max_msg; struct hlist_head free_xfers; DECLARE_HASHTABLE(pending_xfers, SCMI_PENDING_XFERS_HT_ORDER_SZ); }; /** * 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. * @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 { const struct scmi_handle *handle; const struct scmi_protocol *proto; void *gid; refcount_t users; void *priv; struct scmi_protocol_handle ph; }; #define ph_to_pi(h) container_of(h, struct scmi_protocol_instance, ph) /** * 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 */ struct scmi_debug_info { struct dentry *top_dentry; const char *name; const char *type; bool is_atomic; }; /** * 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 { int id; struct device *dev; const struct scmi_desc *desc; struct scmi_revision_info version; struct scmi_handle handle; struct scmi_xfers_info tx_minfo; struct scmi_xfers_info rx_minfo; struct idr tx_idr; struct idr rx_idr; struct idr protocols; /* Ensure mutual exclusive access to protocols instance array */ struct mutex protocols_mtx; u8 *protocols_imp; struct idr active_protocols; unsigned int atomic_threshold; void *notify_priv; struct list_head node; int users; struct notifier_block bus_nb; struct notifier_block dev_req_nb; /* Serialize device creation process for this instance */ struct mutex devreq_mtx; struct scmi_debug_info *dbg; void *raw; }; #define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle) #define bus_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, bus_nb) #define req_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, dev_req_nb) static const struct scmi_protocol *scmi_protocol_get(int protocol_id) { const struct scmi_protocol *proto; proto = idr_find(&scmi_protocols, protocol_id); if (!proto || !try_module_get(proto->owner)) { pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id); return NULL; } pr_debug("Found SCMI Protocol 0x%x\n", protocol_id); return proto; } static void scmi_protocol_put(int protocol_id) { const struct scmi_protocol *proto; proto = idr_find(&scmi_protocols, protocol_id); if (proto) module_put(proto->owner); } int scmi_protocol_register(const struct scmi_protocol *proto) { int ret; if (!proto) { pr_err("invalid protocol\n"); return -EINVAL; } if (!proto->instance_init) { pr_err("missing init for protocol 0x%x\n", proto->id); return -EINVAL; } spin_lock(&protocol_lock); ret = idr_alloc(&scmi_protocols, (void *)proto, proto->id, proto->id + 1, GFP_ATOMIC); spin_unlock(&protocol_lock); if (ret != proto->id) { pr_err("unable to allocate SCMI idr slot for 0x%x - err %d\n", proto->id, ret); return ret; } pr_debug("Registered SCMI Protocol 0x%x\n", proto->id); return 0; } EXPORT_SYMBOL_GPL(scmi_protocol_register); void scmi_protocol_unregister(const struct scmi_protocol *proto) { spin_lock(&protocol_lock); idr_remove(&scmi_protocols, proto->id); spin_unlock(&protocol_lock); pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id); } EXPORT_SYMBOL_GPL(scmi_protocol_unregister); /** * 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) { struct scmi_device *sdev; mutex_lock(&info->devreq_mtx); sdev = scmi_device_create(np, info->dev, prot_id, name); if (name && !sdev) dev_err(info->dev, "failed to create device for protocol 0x%X (%s)\n", prot_id, name); mutex_unlock(&info->devreq_mtx); } static void scmi_destroy_protocol_devices(struct scmi_info *info, int prot_id, const char *name) { mutex_lock(&info->devreq_mtx); scmi_device_destroy(info->dev, prot_id, name); mutex_unlock(&info->devreq_mtx); } void scmi_notification_instance_data_set(const struct scmi_handle *handle, void *priv) { struct scmi_info *info = handle_to_scmi_info(handle); info->notify_priv = priv; /* Ensure updated protocol private date are visible */ smp_wmb(); } void *scmi_notification_instance_data_get(const struct scmi_handle *handle) { struct scmi_info *info = handle_to_scmi_info(handle); /* Ensure protocols_private_data has been updated */ smp_rmb(); return info->notify_priv; } /** * 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) { unsigned long xfer_id, next_token; /* * Pick a candidate monotonic token in range [0, MSG_TOKEN_MAX - 1] * using the pre-allocated transfer_id as a base. * Note that the global transfer_id is shared across all message types * so there could be holes in the allocated set of monotonic sequence * numbers, but that is going to limit the effectiveness of the * mitigation only in very rare limit conditions. */ next_token = (xfer->transfer_id & (MSG_TOKEN_MAX - 1)); /* Pick the next available xfer_id >= next_token */ xfer_id = find_next_zero_bit(minfo->xfer_alloc_table, MSG_TOKEN_MAX, next_token); if (xfer_id == MSG_TOKEN_MAX) { /* * After heavily out-of-order responses, there are no free * tokens ahead, but only at start of xfer_alloc_table so * try again from the beginning. */ xfer_id = find_next_zero_bit(minfo->xfer_alloc_table, MSG_TOKEN_MAX, 0); /* * Something is wrong if we got here since there can be a * maximum number of (MSG_TOKEN_MAX - 1) in-flight messages * but we have not found any free token [0, MSG_TOKEN_MAX - 1]. */ if (WARN_ON_ONCE(xfer_id == MSG_TOKEN_MAX)) return -ENOMEM; } /* Update +/- last_token accordingly if we skipped some hole */ if (xfer_id != next_token) atomic_add((int)(xfer_id - next_token), &transfer_last_id); xfer->hdr.seq = (u16)xfer_id; return 0; } /** * 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) { clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table); } /** * 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) { /* Set in-flight */ set_bit(xfer->hdr.seq, minfo->xfer_alloc_table); hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq); xfer->pending = true; } /** * 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) { int ret = 0; unsigned long flags; spin_lock_irqsave(&minfo->xfer_lock, flags); if (!test_bit(xfer->hdr.seq, minfo->xfer_alloc_table)) scmi_xfer_inflight_register_unlocked(xfer, minfo); else ret = -EBUSY; spin_unlock_irqrestore(&minfo->xfer_lock, flags); return ret; } /** * 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) { struct scmi_info *info = handle_to_scmi_info(handle); return scmi_xfer_inflight_register(xfer, &info->tx_minfo); } /** * 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) { int ret; unsigned long flags; spin_lock_irqsave(&minfo->xfer_lock, flags); /* Set a new monotonic token as the xfer sequence number */ ret = scmi_xfer_token_set(minfo, xfer); if (!ret) scmi_xfer_inflight_register_unlocked(xfer, minfo); spin_unlock_irqrestore(&minfo->xfer_lock, flags); return ret; } /** * 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) { unsigned long flags; struct scmi_xfer *xfer; spin_lock_irqsave(&minfo->xfer_lock, flags); if (hlist_empty(&minfo->free_xfers)) { spin_unlock_irqrestore(&minfo->xfer_lock, flags); return ERR_PTR(-ENOMEM); } /* grab an xfer from the free_list */ xfer = hlist_entry(minfo->free_xfers.first, struct scmi_xfer, node); hlist_del_init(&xfer->node); /* * Allocate transfer_id early so that can be used also as base for * monotonic sequence number generation if needed. */ xfer->transfer_id = atomic_inc_return(&transfer_last_id); refcount_set(&xfer->users, 1); atomic_set(&xfer->busy, SCMI_XFER_FREE); spin_unlock_irqrestore(&minfo->xfer_lock, flags); return xfer; } /** * 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) { struct scmi_xfer *xfer; struct scmi_info *info = handle_to_scmi_info(handle); xfer = scmi_xfer_get(handle, &info->tx_minfo); if (!IS_ERR(xfer)) xfer->flags |= SCMI_XFER_FLAG_IS_RAW; return xfer; } /** * 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) { struct scmi_chan_info *cinfo; struct scmi_info *info = handle_to_scmi_info(handle); cinfo = idr_find(&info->tx_idr, protocol_id); if (!cinfo) { if (protocol_id == SCMI_PROTOCOL_BASE) return ERR_PTR(-EINVAL); /* Use Base channel for protocols not defined for DT */ cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE); if (!cinfo) return ERR_PTR(-EINVAL); dev_warn_once(handle->dev, "Using Base channel for protocol 0x%X\n", protocol_id); } return cinfo; } /** * __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) { unsigned long flags; spin_lock_irqsave(&minfo->xfer_lock, flags); if (refcount_dec_and_test(&xfer->users)) { if (xfer->pending) { scmi_xfer_token_clear(minfo, xfer); hash_del(&xfer->node); xfer->pending = false; } hlist_add_head(&xfer->node, &minfo->free_xfers); } spin_unlock_irqrestore(&minfo->xfer_lock, flags); } /** * 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) { struct scmi_info *info = handle_to_scmi_info(handle); xfer->flags &= ~SCMI_XFER_FLAG_IS_RAW; xfer->flags &= ~SCMI_XFER_FLAG_CHAN_SET; return __scmi_xfer_put(&info->tx_minfo, 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) { struct scmi_xfer *xfer = NULL; if (test_bit(xfer_id, minfo->xfer_alloc_table)) xfer = XFER_FIND(minfo->pending_xfers, xfer_id); return xfer ?: ERR_PTR(-EINVAL); } /** * 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) { /* * Even if a response was indeed expected on this slot at this point, * a buggy platform could wrongly reply feeding us an unexpected * delayed response we're not prepared to handle: bail-out safely * blaming firmware. */ if (msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done) { dev_err(cinfo->dev, "Delayed Response for %d not expected! Buggy F/W ?\n", xfer->hdr.seq); return -EINVAL; } switch (xfer->state) { case SCMI_XFER_SENT_OK: if (msg_type == MSG_TYPE_DELAYED_RESP) { /* * Delayed Response expected but delivered earlier. * Assume message RESPONSE was OK and skip state. */ xfer->hdr.status = SCMI_SUCCESS; xfer->state = SCMI_XFER_RESP_OK; complete(&xfer->done); dev_warn(cinfo->dev, "Received valid OoO Delayed Response for %d\n", xfer->hdr.seq); } break; case SCMI_XFER_RESP_OK: if (msg_type != MSG_TYPE_DELAYED_RESP) return -EINVAL; break; case SCMI_XFER_DRESP_OK: /* No further message expected once in SCMI_XFER_DRESP_OK */ return -EINVAL; } return 0; } /** * 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) { xfer->hdr.type = msg_type; /* Unknown command types were already discarded earlier */ if (xfer->hdr.type == MSG_TYPE_COMMAND) xfer->state = SCMI_XFER_RESP_OK; else xfer->state = SCMI_XFER_DRESP_OK; } static bool scmi_xfer_acquired(struct scmi_xfer *xfer) { int ret; ret = atomic_cmpxchg(&xfer->busy, SCMI_XFER_FREE, SCMI_XFER_BUSY); return ret == SCMI_XFER_FREE; } /** * 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) { int ret; unsigned long flags; struct scmi_xfer *xfer; struct scmi_info *info = handle_to_scmi_info(cinfo->handle); struct scmi_xfers_info *minfo = &info->tx_minfo; u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr); /* Are we even expecting this? */ spin_lock_irqsave(&minfo->xfer_lock, flags); xfer = scmi_xfer_lookup_unlocked(minfo, xfer_id); if (IS_ERR(xfer)) { dev_err(cinfo->dev, "Message for %d type %d is not expected!\n", xfer_id, msg_type); spin_unlock_irqrestore(&minfo->xfer_lock, flags); return xfer; } refcount_inc(&xfer->users); spin_unlock_irqrestore(&minfo->xfer_lock, flags); spin_lock_irqsave(&xfer->lock, flags); ret = scmi_msg_response_validate(cinfo, msg_type, xfer); /* * If a pending xfer was found which was also in a congruent state with * the received message, acquire exclusive access to it setting the busy * flag. * Spins only on the rare limit condition of concurrent reception of * RESP and DRESP for the same xfer. */ if (!ret) { spin_until_cond(scmi_xfer_acquired(xfer)); scmi_xfer_state_update(xfer, msg_type); } spin_unlock_irqrestore(&xfer->lock, flags); if (ret) { dev_err(cinfo->dev, "Invalid message type:%d for %d - HDR:0x%X state:%d\n", msg_type, xfer_id, msg_hdr, xfer->state); /* On error the refcount incremented above has to be dropped */ __scmi_xfer_put(minfo, xfer); xfer = ERR_PTR(-EINVAL); } return xfer; } static inline void scmi_xfer_command_release(struct scmi_info *info, struct scmi_xfer *xfer) { atomic_set(&xfer->busy, SCMI_XFER_FREE); __scmi_xfer_put(&info->tx_minfo, xfer); } static inline void scmi_clear_channel(struct scmi_info *info, struct scmi_chan_info *cinfo) { if (info->desc->ops->clear_channel) info->desc->ops->clear_channel(cinfo); } static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { struct scmi_xfer *xfer; struct device *dev = cinfo->dev; struct scmi_info *info = handle_to_scmi_info(cinfo->handle); struct scmi_xfers_info *minfo = &info->rx_minfo; ktime_t ts; ts = ktime_get_boottime(); xfer = scmi_xfer_get(cinfo->handle, minfo); if (IS_ERR(xfer)) { dev_err(dev, "failed to get free message slot (%ld)\n", PTR_ERR(xfer)); scmi_clear_channel(info, cinfo); return; } unpack_scmi_header(msg_hdr, &xfer->hdr); if (priv) /* Ensure order between xfer->priv store and following ops */ smp_store_mb(xfer->priv, priv); info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size, xfer); trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, xfer->hdr.id, "NOTI", xfer->hdr.seq, xfer->hdr.status, xfer->rx.buf, xfer->rx.len); scmi_notify(cinfo->handle, xfer->hdr.protocol_id, xfer->hdr.id, xfer->rx.buf, xfer->rx.len, ts); trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, MSG_TYPE_NOTIFICATION); if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { xfer->hdr.seq = MSG_XTRACT_TOKEN(msg_hdr); scmi_raw_message_report(info->raw, xfer, SCMI_RAW_NOTIF_QUEUE, cinfo->id); } __scmi_xfer_put(minfo, xfer); scmi_clear_channel(info, cinfo); } static void scmi_handle_response(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { struct scmi_xfer *xfer; struct scmi_info *info = handle_to_scmi_info(cinfo->handle); xfer = scmi_xfer_command_acquire(cinfo, msg_hdr); if (IS_ERR(xfer)) { if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) scmi_raw_error_report(info->raw, cinfo, msg_hdr, priv); if (MSG_XTRACT_TYPE(msg_hdr) == MSG_TYPE_DELAYED_RESP) scmi_clear_channel(info, cinfo); return; } /* rx.len could be shrunk in the sync do_xfer, so reset to maxsz */ if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) xfer->rx.len = info->desc->max_msg_size; if (priv) /* Ensure order between xfer->priv store and following ops */ smp_store_mb(xfer->priv, priv); info->desc->ops->fetch_response(cinfo, xfer); trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, xfer->hdr.id, xfer->hdr.type == MSG_TYPE_DELAYED_RESP ? (!SCMI_XFER_IS_RAW(xfer) ? "DLYD" : "dlyd") : (!SCMI_XFER_IS_RAW(xfer) ? "RESP" : "resp"), xfer->hdr.seq, xfer->hdr.status, xfer->rx.buf, xfer->rx.len); trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.type); if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) { scmi_clear_channel(info, cinfo); complete(xfer->async_done); } else { complete(&xfer->done); } if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { /* * When in polling mode avoid to queue the Raw xfer on the IRQ * RX path since it will be already queued at the end of the TX * poll loop. */ if (!xfer->hdr.poll_completion) scmi_raw_message_report(info->raw, xfer, SCMI_RAW_REPLY_QUEUE, cinfo->id); } scmi_xfer_command_release(info, xfer); } /** * 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. */ void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, void *priv) { u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); switch (msg_type) { case MSG_TYPE_NOTIFICATION: scmi_handle_notification(cinfo, msg_hdr, priv); break; case MSG_TYPE_COMMAND: case MSG_TYPE_DELAYED_RESP: scmi_handle_response(cinfo, msg_hdr, priv); break; default: WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type); break; } } /** * 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) { const struct scmi_protocol_instance *pi = ph_to_pi(ph); struct scmi_info *info = handle_to_scmi_info(pi->handle); __scmi_xfer_put(&info->tx_minfo, xfer); } static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer, ktime_t stop) { struct scmi_info *info = handle_to_scmi_info(cinfo->handle); /* * Poll also on xfer->done so that polling can be forcibly terminated * in case of out-of-order receptions of delayed responses */ return info->desc->ops->poll_done(cinfo, xfer) || try_wait_for_completion(&xfer->done) || ktime_after(ktime_get(), 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) { int ret = 0; if (xfer->hdr.poll_completion) { /* * Real polling is needed only if transport has NOT declared * itself to support synchronous commands replies. */ if (!desc->sync_cmds_completed_on_ret) { /* * Poll on xfer using transport provided .poll_done(); * assumes no completion interrupt was available. */ ktime_t stop = ktime_add_ms(ktime_get(), timeout_ms); spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop)); if (ktime_after(ktime_get(), stop)) { dev_err(dev, "timed out in resp(caller: %pS) - polling\n", (void *)_RET_IP_); ret = -ETIMEDOUT; } } if (!ret) { unsigned long flags; struct scmi_info *info = handle_to_scmi_info(cinfo->handle); /* * Do not fetch_response if an out-of-order delayed * response is being processed. */ spin_lock_irqsave(&xfer->lock, flags); if (xfer->state == SCMI_XFER_SENT_OK) { desc->ops->fetch_response(cinfo, xfer); xfer->state = SCMI_XFER_RESP_OK; } spin_unlock_irqrestore(&xfer->lock, flags); /* Trace polled replies. */ trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, xfer->hdr.id, !SCMI_XFER_IS_RAW(xfer) ? "RESP" : "resp", xfer->hdr.seq, xfer->hdr.status, xfer->rx.buf, xfer->rx.len); if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { struct scmi_info *info = handle_to_scmi_info(cinfo->handle); scmi_raw_message_report(info->raw, xfer, SCMI_RAW_REPLY_QUEUE, cinfo->id); } } } else { /* And we wait for the response. */ if (!wait_for_completion_timeout(&xfer->done, msecs_to_jiffies(timeout_ms))) { dev_err(dev, "timed out in resp(caller: %pS)\n", (void *)_RET_IP_); ret = -ETIMEDOUT; } } return ret; } /** * 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) { struct scmi_info *info = handle_to_scmi_info(cinfo->handle); struct device *dev = info->dev; trace_scmi_xfer_response_wait(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, info->desc->max_rx_timeout_ms, xfer->hdr.poll_completion); return scmi_wait_for_reply(dev, info->desc, cinfo, xfer, info->desc->max_rx_timeout_ms); } /** * 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) { int ret; struct scmi_info *info = handle_to_scmi_info(cinfo->handle); struct device *dev = info->dev; ret = scmi_wait_for_reply(dev, info->desc, cinfo, xfer, timeout_ms); if (ret) dev_dbg(dev, "timed out in RAW response - HDR:%08X\n", pack_scmi_header(&xfer->hdr)); return ret; } /** * 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) { int ret; const struct scmi_protocol_instance *pi = ph_to_pi(ph); struct scmi_info *info = handle_to_scmi_info(pi->handle); struct device *dev = info->dev; struct scmi_chan_info *cinfo; /* Check for polling request on custom command xfers at first */ if (xfer->hdr.poll_completion && !is_transport_polling_capable(info->desc)) { dev_warn_once(dev, "Polling mode is not supported by transport.\n"); return -EINVAL; } cinfo = idr_find(&info->tx_idr, pi->proto->id); if (unlikely(!cinfo)) return -EINVAL; /* True ONLY if also supported by transport. */ if (is_polling_enabled(cinfo, info->desc)) xfer->hdr.poll_completion = true; /* * Initialise protocol id now from protocol handle to avoid it being * overridden by mistake (or malice) by the protocol code mangling with * the scmi_xfer structure prior to this. */ xfer->hdr.protocol_id = pi->proto->id; reinit_completion(&xfer->done); trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.poll_completion); /* Clear any stale status */ xfer->hdr.status = SCMI_SUCCESS; xfer->state = SCMI_XFER_SENT_OK; /* * Even though spinlocking is not needed here since no race is possible * on xfer->state due to the monotonically increasing tokens allocation, * we must anyway ensure xfer->state initialization is not re-ordered * after the .send_message() to be sure that on the RX path an early * ISR calling scmi_rx_callback() cannot see an old stale xfer->state. */ smp_mb(); ret = info->desc->ops->send_message(cinfo, xfer); if (ret < 0) { dev_dbg(dev, "Failed to send message %d\n", ret); return ret; } trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id, xfer->hdr.id, "CMND", xfer->hdr.seq, xfer->hdr.status, xfer->tx.buf, xfer->tx.len); ret = scmi_wait_for_message_response(cinfo, xfer); if (!ret && xfer->hdr.status) ret = scmi_to_linux_errno(xfer->hdr.status); if (info->desc->ops->mark_txdone) info->desc->ops->mark_txdone(cinfo, ret, xfer); trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, ret); return ret; } static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph, struct scmi_xfer *xfer) { const struct scmi_protocol_instance *pi = ph_to_pi(ph); struct scmi_info *info = handle_to_scmi_info(pi->handle); xfer->rx.len = info->desc->max_msg_size; } /** * 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) { int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT); DECLARE_COMPLETION_ONSTACK(async_response); xfer->async_done = &async_response; /* * Delayed responses should not be polled, so an async command should * not have been used when requiring an atomic/poll context; WARN and * perform instead a sleeping wait. * (Note Async + IgnoreDelayedResponses are sent via do_xfer) */ WARN_ON_ONCE(xfer->hdr.poll_completion); ret = do_xfer(ph, xfer); if (!ret) { if (!wait_for_completion_timeout(xfer->async_done, timeout)) { dev_err(ph->dev, "timed out in delayed resp(caller: %pS)\n", (void *)_RET_IP_); ret = -ETIMEDOUT; } else if (xfer->hdr.status) { ret = scmi_to_linux_errno(xfer->hdr.status); } } xfer->async_done = NULL; return ret; } /** * 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) { int ret; struct scmi_xfer *xfer; const struct scmi_protocol_instance *pi = ph_to_pi(ph); struct scmi_info *info = handle_to_scmi_info(pi->handle); struct scmi_xfers_info *minfo = &info->tx_minfo; struct device *dev = info->dev; /* Ensure we have sane transfer sizes */ if (rx_size > info->desc->max_msg_size || tx_size > info->desc->max_msg_size) return -ERANGE; xfer = scmi_xfer_get(pi->handle, minfo); if (IS_ERR(xfer)) { ret = PTR_ERR(xfer); dev_err(dev, "failed to get free message slot(%d)\n", ret); return ret; } /* Pick a sequence number and register this xfer as in-flight */ ret = scmi_xfer_pending_set(xfer, minfo); if (ret) { dev_err(pi->handle->dev, "Failed to get monotonic token %d\n", ret); __scmi_xfer_put(minfo, xfer); return ret; } xfer->tx.len = tx_size; xfer->rx.len = rx_size ? : info->desc->max_msg_size; xfer->hdr.type = MSG_TYPE_COMMAND; xfer->hdr.id = msg_id; xfer->hdr.poll_completion = false; *p = xfer; return 0; } /** * 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) { int ret; __le32 *rev_info; struct scmi_xfer *t; ret = xfer_get_init(ph, PROTOCOL_VERSION, 0, sizeof(*version), &t); if (ret) return ret; ret = do_xfer(ph, t); if (!ret) { rev_info = t->rx.buf; *version = le32_to_cpu(*rev_info); } xfer_put(ph, t); return ret; } /** * scmi_set_protocol_priv - Set protocol specific data at init time * * @ph: A reference to the protocol handle. * @priv: The private data to set. * * Return: 0 on Success */ static int scmi_set_protocol_priv(const struct scmi_protocol_handle *ph, void *priv) { struct scmi_protocol_instance *pi = ph_to_pi(ph); pi->priv = priv; return 0; } /** * 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) { const struct scmi_protocol_instance *pi = ph_to_pi(ph); return pi->priv; } static const struct scmi_xfer_ops xfer_ops = { .version_get = version_get, .xfer_get_init = xfer_get_init, .reset_rx_to_maxsz = reset_rx_to_maxsz, .do_xfer = do_xfer, .do_xfer_with_response = do_xfer_with_response, .xfer_put = xfer_put, }; struct scmi_msg_resp_domain_name_get { __le32 flags; u8 name[SCMI_MAX_STR_SIZE]; }; /** * 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. * @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, char *name, size_t len) { int ret; struct scmi_xfer *t; struct scmi_msg_resp_domain_name_get *resp; ret = ph->xops->xfer_get_init(ph, cmd_id, sizeof(res_id), sizeof(*resp), &t); if (ret) goto out; put_unaligned_le32(res_id, t->tx.buf); resp = t->rx.buf; ret = ph->xops->do_xfer(ph, t); if (!ret) strscpy(name, resp->name, len); ph->xops->xfer_put(ph, t); out: if (ret) dev_warn(ph->dev, "Failed to get extended name - id:%u (ret:%d). Using %s\n", res_id, ret, name); return ret; } /** * 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 { void *msg; void *resp; struct scmi_xfer *t; const struct scmi_protocol_handle *ph; struct scmi_iterator_ops *ops; struct scmi_iterator_state state; void *priv; }; 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) { int ret; struct scmi_iterator *i; i = devm_kzalloc(ph->dev, sizeof(*i), GFP_KERNEL); if (!i) return ERR_PTR(-ENOMEM); i->ph = ph; i->ops = ops; i->priv = priv; ret = ph->xops->xfer_get_init(ph, msg_id, tx_size, 0, &i->t); if (ret) { devm_kfree(ph->dev, i); return ERR_PTR(ret); } i->state.max_resources = max_resources; i->msg = i->t->tx.buf; i->resp = i->t->rx.buf; return i; } static int scmi_iterator_run(void *iter) { int ret = -EINVAL; struct scmi_iterator_ops *iops; const struct scmi_protocol_handle *ph; struct scmi_iterator_state *st; struct scmi_iterator *i = iter; if (!i || !i->ops || !i->ph) return ret; iops = i->ops; ph = i->ph; st = &i->state; do { iops->prepare_message(i->msg, st->desc_index, i->priv); ret = ph->xops->do_xfer(ph, i->t); if (ret) break; st->rx_len = i->t->rx.len; ret = iops->update_state(st, i->resp, i->priv); if (ret) break; if (st->num_returned > st->max_resources - st->desc_index) { dev_err(ph->dev, "No. of resources can't exceed %d\n", st->max_resources); ret = -EINVAL; break; } for (st->loop_idx = 0; st->loop_idx < st->num_returned; st->loop_idx++) { ret = iops->process_response(ph, i->resp, st, i->priv); if (ret) goto out; } st->desc_index += st->num_returned; ph->xops->reset_rx_to_maxsz(ph, i->t); /* * check for both returned and remaining to avoid infinite * loop due to buggy firmware */ } while (st->num_returned && st->num_remaining); out: /* Finalize and destroy iterator */ ph->xops->xfer_put(ph, i->t); devm_kfree(ph->dev, i); return ret; } struct scmi_msg_get_fc_info { __le32 domain; __le32 message_id; }; struct scmi_msg_resp_desc_fc { __le32 attr; #define SUPPORTS_DOORBELL(x) ((x) & BIT(0)) #define DOORBELL_REG_WIDTH(x) FIELD_GET(GENMASK(2, 1), (x)) __le32 rate_limit; __le32 chan_addr_low; __le32 chan_addr_high; __le32 chan_size; __le32 db_addr_low; __le32 db_addr_high; __le32 db_set_lmask; __le32 db_set_hmask; __le32 db_preserve_lmask; __le32 db_preserve_hmask; }; 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) { int ret; u32 flags; u64 phys_addr; u8 size; void __iomem *addr; struct scmi_xfer *t; struct scmi_fc_db_info *db = NULL; struct scmi_msg_get_fc_info *info; struct scmi_msg_resp_desc_fc *resp; const struct scmi_protocol_instance *pi = ph_to_pi(ph); if (!p_addr) { ret = -EINVAL; goto err_out; } ret = ph->xops->xfer_get_init(ph, describe_id, sizeof(*info), sizeof(*resp), &t); if (ret) goto err_out; info = t->tx.buf; info->domain = cpu_to_le32(domain); info->message_id = cpu_to_le32(message_id); /* * Bail out on error leaving fc_info addresses zeroed; this includes * the case in which the requested domain/message_id does NOT support * fastchannels at all. */ ret = ph->xops->do_xfer(ph, t); if (ret) goto err_xfer; resp = t->rx.buf; flags = le32_to_cpu(resp->attr); size = le32_to_cpu(resp->chan_size); if (size != valid_size) { ret = -EINVAL; goto err_xfer; } phys_addr = le32_to_cpu(resp->chan_addr_low); phys_addr |= (u64)le32_to_cpu(resp->chan_addr_high) << 32; addr = devm_ioremap(ph->dev, phys_addr, size); if (!addr) { ret = -EADDRNOTAVAIL; goto err_xfer; } *p_addr = addr; if (p_db && SUPPORTS_DOORBELL(flags)) { db = devm_kzalloc(ph->dev, sizeof(*db), GFP_KERNEL); if (!db) { ret = -ENOMEM; goto err_db; } size = 1 << DOORBELL_REG_WIDTH(flags); phys_addr = le32_to_cpu(resp->db_addr_low); phys_addr |= (u64)le32_to_cpu(resp->db_addr_high) << 32; addr = devm_ioremap(ph->dev, phys_addr, size); if (!addr) { ret = -EADDRNOTAVAIL; goto err_db_mem; } db->addr = addr; db->width = size; db->set = le32_to_cpu(resp->db_set_lmask); db->set |= (u64)le32_to_cpu(resp->db_set_hmask) << 32; db->mask = le32_to_cpu(resp->db_preserve_lmask); db->mask |= (u64)le32_to_cpu(resp->db_preserve_hmask) << 32; *p_db = db; } ph->xops->xfer_put(ph, t); dev_dbg(ph->dev, "Using valid FC for protocol %X [MSG_ID:%u / RES_ID:%u]\n", pi->proto->id, message_id, domain); return; err_db_mem: devm_kfree(ph->dev, db); err_db: *p_addr = NULL; err_xfer: ph->xops->xfer_put(ph, t); err_out: dev_warn(ph->dev, "Failed to get FC for protocol %X [MSG_ID:%u / RES_ID:%u] - ret:%d. Using regular messaging.\n", pi->proto->id, message_id, domain, ret); } #define SCMI_PROTO_FC_RING_DB(w) \ do { \ u##w val = 0; \ \ if (db->mask) \ val = ioread##w(db->addr) & db->mask; \ iowrite##w((u##w)db->set | val, db->addr); \ } while (0) static void scmi_common_fastchannel_db_ring(struct scmi_fc_db_info *db) { if (!db || !db->addr) return; if (db->width == 1) SCMI_PROTO_FC_RING_DB(8); else if (db->width == 2) SCMI_PROTO_FC_RING_DB(16); else if (db->width == 4) SCMI_PROTO_FC_RING_DB(32); else /* db->width == 8 */ #ifdef CONFIG_64BIT SCMI_PROTO_FC_RING_DB(64); #else { u64 val = 0; if (db->mask) val = ioread64_hi_lo(db->addr) & db->mask; iowrite64_hi_lo(db->set | val, db->addr); } #endif } static const struct scmi_proto_helpers_ops helpers_ops = { .extended_name_get = scmi_common_extended_name_get, .iter_response_init = scmi_iterator_init, .iter_response_run = scmi_iterator_run, .fastchannel_init = scmi_common_fastchannel_init, .fastchannel_db_ring = scmi_common_fastchannel_db_ring, }; /** * 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) { const struct scmi_protocol_instance *pi = ph_to_pi(ph); return pi->handle->version; } /** * 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) { int ret = -ENOMEM; void *gid; struct scmi_protocol_instance *pi; const struct scmi_handle *handle = &info->handle; /* Protocol specific devres group */ gid = devres_open_group(handle->dev, NULL, GFP_KERNEL); if (!gid) { scmi_protocol_put(proto->id); goto out; } pi = devm_kzalloc(handle->dev, sizeof(*pi), GFP_KERNEL); if (!pi) goto clean; pi->gid = gid; pi->proto = proto; pi->handle = handle; pi->ph.dev = handle->dev; pi->ph.xops = &xfer_ops; pi->ph.hops = &helpers_ops; pi->ph.set_priv = scmi_set_protocol_priv; pi->ph.get_priv = scmi_get_protocol_priv; refcount_set(&pi->users, 1); /* proto->init is assured NON NULL by scmi_protocol_register */ ret = pi->proto->instance_init(&pi->ph); if (ret) goto clean; ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1, GFP_KERNEL); if (ret != proto->id) goto clean; /* * Warn but ignore events registration errors since we do not want * to skip whole protocols if their notifications are messed up. */ if (pi->proto->events) { ret = scmi_register_protocol_events(handle, pi->proto->id, &pi->ph, pi->proto->events); if (ret) dev_warn(handle->dev, "Protocol:%X - Events Registration Failed - err:%d\n", pi->proto->id, ret); } devres_close_group(handle->dev, pi->gid); dev_dbg(handle->dev, "Initialized protocol: 0x%X\n", pi->proto->id); return pi; clean: /* Take care to put the protocol module's owner before releasing all */ scmi_protocol_put(proto->id); devres_release_group(handle->dev, gid); out: return ERR_PTR(ret); } /** * 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) { struct scmi_protocol_instance *pi; struct scmi_info *info = handle_to_scmi_info(handle); mutex_lock(&info->protocols_mtx); pi = idr_find(&info->protocols, protocol_id); if (pi) { refcount_inc(&pi->users); } else { const struct scmi_protocol *proto; /* Fails if protocol not registered on bus */ proto = scmi_protocol_get(protocol_id); if (proto) pi = scmi_alloc_init_protocol_instance(info, proto); else pi = ERR_PTR(-EPROBE_DEFER); } mutex_unlock(&info->protocols_mtx); return pi; } /** * 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) { return PTR_ERR_OR_ZERO(scmi_get_protocol_instance(handle, 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) { struct scmi_info *info = handle_to_scmi_info(handle); struct scmi_protocol_instance *pi; mutex_lock(&info->protocols_mtx); pi = idr_find(&info->protocols, protocol_id); if (WARN_ON(!pi)) goto out; if (refcount_dec_and_test(&pi->users)) { void *gid = pi->gid; if (pi->proto->events) scmi_deregister_protocol_events(handle, protocol_id); if (pi->proto->instance_deinit) pi->proto->instance_deinit(&pi->ph); idr_remove(&info->protocols, protocol_id); scmi_protocol_put(protocol_id); devres_release_group(handle->dev, gid); dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n", protocol_id); } out: mutex_unlock(&info->protocols_mtx); } void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, u8 *prot_imp) { const struct scmi_protocol_instance *pi = ph_to_pi(ph); struct scmi_info *info = handle_to_scmi_info(pi->handle); info->protocols_imp = prot_imp; } static bool scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) { int i; struct scmi_info *info = handle_to_scmi_info(handle); struct scmi_revision_info *rev = handle->version; if (!info->protocols_imp) return false; for (i = 0; i < rev->num_protocols; i++) if (info->protocols_imp[i] == prot_id) return true; return false; } struct scmi_protocol_devres { const struct scmi_handle *handle; u8 protocol_id; }; static void scmi_devm_release_protocol(struct device *dev, void *res) { struct scmi_protocol_devres *dres = res; scmi_protocol_release(dres->handle, dres->protocol_id); } static struct scmi_protocol_instance __must_check * scmi_devres_protocol_instance_get(struct scmi_device *sdev, u8 protocol_id) { struct scmi_protocol_instance *pi; struct scmi_protocol_devres *dres; dres = devres_alloc(scmi_devm_release_protocol, sizeof(*dres), GFP_KERNEL); if (!dres) return ERR_PTR(-ENOMEM); pi = scmi_get_protocol_instance(sdev->handle, protocol_id); if (IS_ERR(pi)) { devres_free(dres); return pi; } dres->handle = sdev->handle; dres->protocol_id = protocol_id; devres_add(&sdev->dev, dres); return pi; } /** * 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) { struct scmi_protocol_instance *pi; if (!ph) return ERR_PTR(-EINVAL); pi = scmi_devres_protocol_instance_get(sdev, protocol_id); if (IS_ERR(pi)) return pi; *ph = &pi->ph; return pi->proto->ops; } /** * 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) { struct scmi_protocol_instance *pi; pi = scmi_devres_protocol_instance_get(sdev, protocol_id); if (IS_ERR(pi)) return PTR_ERR(pi); return 0; } static int scmi_devm_protocol_match(struct device *dev, void *res, void *data) { struct scmi_protocol_devres *dres = res; if (WARN_ON(!dres || !data)) return 0; return dres->protocol_id == *((u8 *)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) { int ret; ret = devres_release(&sdev->dev, scmi_devm_release_protocol, scmi_devm_protocol_match, &protocol_id); WARN_ON(ret); } /** * 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) { bool ret; struct scmi_info *info = handle_to_scmi_info(handle); ret = info->desc->atomic_enabled && is_transport_polling_capable(info->desc); if (ret && atomic_threshold) *atomic_threshold = info->atomic_threshold; return ret; } /** * 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) { struct list_head *p; struct scmi_info *info; struct scmi_handle *handle = NULL; mutex_lock(&scmi_list_mutex); list_for_each(p, &scmi_list) { info = list_entry(p, struct scmi_info, node); if (dev->parent == info->dev) { info->users++; handle = &info->handle; break; } } mutex_unlock(&scmi_list_mutex); return handle; } /** * 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) { struct scmi_info *info; if (!handle) return -EINVAL; info = handle_to_scmi_info(handle); mutex_lock(&scmi_list_mutex); if (!WARN_ON(!info->users)) info->users--; mutex_unlock(&scmi_list_mutex); return 0; } static void scmi_device_link_add(struct device *consumer, struct device *supplier) { struct device_link *link; link = device_link_add(consumer, supplier, DL_FLAG_AUTOREMOVE_CONSUMER); WARN_ON(!link); } static void scmi_set_handle(struct scmi_device *scmi_dev) { scmi_dev->handle = scmi_handle_get(&scmi_dev->dev); if (scmi_dev->handle) scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev); } static int __scmi_xfer_info_init(struct scmi_info *sinfo, struct scmi_xfers_info *info) { int i; struct scmi_xfer *xfer; struct device *dev = sinfo->dev; const struct scmi_desc *desc = sinfo->desc; /* Pre-allocated messages, no more than what hdr.seq can support */ if (WARN_ON(!info->max_msg || info->max_msg > MSG_TOKEN_MAX)) { dev_err(dev, "Invalid maximum messages %d, not in range [1 - %lu]\n", info->max_msg, MSG_TOKEN_MAX); return -EINVAL; } hash_init(info->pending_xfers); /* Allocate a bitmask sized to hold MSG_TOKEN_MAX tokens */ info->xfer_alloc_table = devm_bitmap_zalloc(dev, MSG_TOKEN_MAX, GFP_KERNEL); if (!info->xfer_alloc_table) return -ENOMEM; /* * Preallocate a number of xfers equal to max inflight messages, * pre-initialize the buffer pointer to pre-allocated buffers and * attach all of them to the free list */ INIT_HLIST_HEAD(&info->free_xfers); for (i = 0; i < info->max_msg; i++) { xfer = devm_kzalloc(dev, sizeof(*xfer), GFP_KERNEL); if (!xfer) return -ENOMEM; xfer->rx.buf = devm_kcalloc(dev, sizeof(u8), desc->max_msg_size, GFP_KERNEL); if (!xfer->rx.buf) return -ENOMEM; xfer->tx.buf = xfer->rx.buf; init_completion(&xfer->done); spin_lock_init(&xfer->lock); /* Add initialized xfer to the free list */ hlist_add_head(&xfer->node, &info->free_xfers); } spin_lock_init(&info->xfer_lock); return 0; } static int scmi_channels_max_msg_configure(struct scmi_info *sinfo) { const struct scmi_desc *desc = sinfo->desc; if (!desc->ops->get_max_msg) { sinfo->tx_minfo.max_msg = desc->max_msg; sinfo->rx_minfo.max_msg = desc->max_msg; } else { struct scmi_chan_info *base_cinfo; base_cinfo = idr_find(&sinfo->tx_idr, SCMI_PROTOCOL_BASE); if (!base_cinfo) return -EINVAL; sinfo->tx_minfo.max_msg = desc->ops->get_max_msg(base_cinfo); /* RX channel is optional so can be skipped */ base_cinfo = idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE); if (base_cinfo) sinfo->rx_minfo.max_msg = desc->ops->get_max_msg(base_cinfo); } return 0; } static int scmi_xfer_info_init(struct scmi_info *sinfo) { int ret; ret = scmi_channels_max_msg_configure(sinfo); if (ret) return ret; ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo); if (!ret && !idr_is_empty(&sinfo->rx_idr)) ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo); return ret; } static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node, int prot_id, bool tx) { int ret, idx; char name[32]; struct scmi_chan_info *cinfo; struct idr *idr; struct scmi_device *tdev = NULL; /* Transmit channel is first entry i.e. index 0 */ idx = tx ? 0 : 1; idr = tx ? &info->tx_idr : &info->rx_idr; if (!info->desc->ops->chan_available(of_node, idx)) { cinfo = idr_find(idr, SCMI_PROTOCOL_BASE); if (unlikely(!cinfo)) /* Possible only if platform has no Rx */ return -EINVAL; goto idr_alloc; } cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL); if (!cinfo) return -ENOMEM; cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms; /* Create a unique name for this transport device */ snprintf(name, 32, "__scmi_transport_device_%s_%02X", idx ? "rx" : "tx", prot_id); /* Create a uniquely named, dedicated transport device for this chan */ tdev = scmi_device_create(of_node, info->dev, prot_id, name); if (!tdev) { dev_err(info->dev, "failed to create transport device (%s)\n", name); devm_kfree(info->dev, cinfo); return -EINVAL; } of_node_get(of_node); cinfo->id = prot_id; cinfo->dev = &tdev->dev; ret = info->desc->ops->chan_setup(cinfo, info->dev, tx); if (ret) { of_node_put(of_node); scmi_device_destroy(info->dev, prot_id, name); devm_kfree(info->dev, cinfo); return ret; } if (tx && is_polling_required(cinfo, info->desc)) { if (is_transport_polling_capable(info->desc)) dev_info(&tdev->dev, "Enabled polling mode TX channel - prot_id:%d\n", prot_id); else dev_warn(&tdev->dev, "Polling mode NOT supported by transport.\n"); } idr_alloc: ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); if (ret != prot_id) { dev_err(info->dev, "unable to allocate SCMI idr slot err %d\n", ret); /* Destroy channel and device only if created by this call. */ if (tdev) { of_node_put(of_node); scmi_device_destroy(info->dev, prot_id, name); devm_kfree(info->dev, cinfo); } return ret; } cinfo->handle = &info->handle; return 0; } static inline int scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node, int prot_id) { int ret = scmi_chan_setup(info, of_node, prot_id, true); if (!ret) { /* Rx is optional, report only memory errors */ ret = scmi_chan_setup(info, of_node, prot_id, false); if (ret && ret != -ENOMEM) ret = 0; } return ret; } /** * 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) { int ret; struct device_node *child, *top_np = info->dev->of_node; /* Initialize a common generic channel at first */ ret = scmi_txrx_setup(info, top_np, SCMI_PROTOCOL_BASE); if (ret) return ret; for_each_available_child_of_node(top_np, child) { u32 prot_id; if (of_property_read_u32(child, "reg", &prot_id)) continue; if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id)) dev_err(info->dev, "Out of range protocol %d\n", prot_id); ret = scmi_txrx_setup(info, child, prot_id); if (ret) { of_node_put(child); return ret; } } return 0; } static int scmi_chan_destroy(int id, void *p, void *idr) { struct scmi_chan_info *cinfo = p; if (cinfo->dev) { struct scmi_info *info = handle_to_scmi_info(cinfo->handle); struct scmi_device *sdev = to_scmi_dev(cinfo->dev); of_node_put(cinfo->dev->of_node); scmi_device_destroy(info->dev, id, sdev->name); cinfo->dev = NULL; } idr_remove(idr, id); return 0; } static void scmi_cleanup_channels(struct scmi_info *info, struct idr *idr) { /* At first free all channels at the transport layer ... */ idr_for_each(idr, info->desc->ops->chan_free, idr); /* ...then destroy all underlying devices */ idr_for_each(idr, scmi_chan_destroy, idr); idr_destroy(idr); } static void scmi_cleanup_txrx_channels(struct scmi_info *info) { scmi_cleanup_channels(info, &info->tx_idr); scmi_cleanup_channels(info, &info->rx_idr); } static int scmi_bus_notifier(struct notifier_block *nb, unsigned long action, void *data) { struct scmi_info *info = bus_nb_to_scmi_info(nb); struct scmi_device *sdev = to_scmi_dev(data); /* Skip transport devices and devices of different SCMI instances */ if (!strncmp(sdev->name, "__scmi_transport_device", 23) || sdev->dev.parent != info->dev) return NOTIFY_DONE; switch (action) { case BUS_NOTIFY_BIND_DRIVER: /* setup handle now as the transport is ready */ scmi_set_handle(sdev); break; case BUS_NOTIFY_UNBOUND_DRIVER: scmi_handle_put(sdev->handle); sdev->handle = NULL; break; default: return NOTIFY_DONE; } dev_dbg(info->dev, "Device %s (%s) is now %s\n", dev_name(&sdev->dev), sdev->name, action == BUS_NOTIFY_BIND_DRIVER ? "about to be BOUND." : "UNBOUND."); return NOTIFY_OK; } static int scmi_device_request_notifier(struct notifier_block *nb, unsigned long action, void *data) { struct device_node *np; struct scmi_device_id *id_table = data; struct scmi_info *info = req_nb_to_scmi_info(nb); np = idr_find(&info->active_protocols, id_table->protocol_id); if (!np) return NOTIFY_DONE; dev_dbg(info->dev, "%sRequested device (%s) for protocol 0x%x\n", action == SCMI_BUS_NOTIFY_DEVICE_REQUEST ? "" : "UN-", id_table->name, id_table->protocol_id); switch (action) { case SCMI_BUS_NOTIFY_DEVICE_REQUEST: scmi_create_protocol_devices(np, info, id_table->protocol_id, id_table->name); break; case SCMI_BUS_NOTIFY_DEVICE_UNREQUEST: scmi_destroy_protocol_devices(info, id_table->protocol_id, id_table->name); break; default: return NOTIFY_DONE; } return NOTIFY_OK; } static void scmi_debugfs_common_cleanup(void *d) { struct scmi_debug_info *dbg = d; if (!dbg) return; debugfs_remove_recursive(dbg->top_dentry); kfree(dbg->name); kfree(dbg->type); } static struct scmi_debug_info *scmi_debugfs_common_setup(struct scmi_info *info) { char top_dir[16]; struct dentry *trans, *top_dentry; struct scmi_debug_info *dbg; const char *c_ptr = NULL; dbg = devm_kzalloc(info->dev, sizeof(*dbg), GFP_KERNEL); if (!dbg) return NULL; dbg->name = kstrdup(of_node_full_name(info->dev->of_node), GFP_KERNEL); if (!dbg->name) { devm_kfree(info->dev, dbg); return NULL; } of_property_read_string(info->dev->of_node, "compatible", &c_ptr); dbg->type = kstrdup(c_ptr, GFP_KERNEL); if (!dbg->type) { kfree(dbg->name); devm_kfree(info->dev, dbg); return NULL; } snprintf(top_dir, 16, "%d", info->id); top_dentry = debugfs_create_dir(top_dir, scmi_top_dentry); trans = debugfs_create_dir("transport", top_dentry); dbg->is_atomic = info->desc->atomic_enabled && is_transport_polling_capable(info->desc); debugfs_create_str("instance_name", 0400, top_dentry, (char **)&dbg->name); debugfs_create_u32("atomic_threshold_us", 0400, top_dentry, &info->atomic_threshold); debugfs_create_str("type", 0400, trans, (char **)&dbg->type); debugfs_create_bool("is_atomic", 0400, trans, &dbg->is_atomic); debugfs_create_u32("max_rx_timeout_ms", 0400, trans, (u32 *)&info->desc->max_rx_timeout_ms); debugfs_create_u32("max_msg_size", 0400, trans, (u32 *)&info->desc->max_msg_size); debugfs_create_u32("tx_max_msg", 0400, trans, (u32 *)&info->tx_minfo.max_msg); debugfs_create_u32("rx_max_msg", 0400, trans, (u32 *)&info->rx_minfo.max_msg); dbg->top_dentry = top_dentry; if (devm_add_action_or_reset(info->dev, scmi_debugfs_common_cleanup, dbg)) { scmi_debugfs_common_cleanup(dbg); return NULL; } return dbg; } static int scmi_debugfs_raw_mode_setup(struct scmi_info *info) { int id, num_chans = 0, ret = 0; struct scmi_chan_info *cinfo; u8 channels[SCMI_MAX_CHANNELS] = {}; DECLARE_BITMAP(protos, SCMI_MAX_CHANNELS) = {}; if (!info->dbg) return -EINVAL; /* Enumerate all channels to collect their ids */ idr_for_each_entry(&info->tx_idr, cinfo, id) { /* * Cannot happen, but be defensive. * Zero as num_chans is ok, warn and carry on. */ if (num_chans >= SCMI_MAX_CHANNELS || !cinfo) { dev_warn(info->dev, "SCMI RAW - Error enumerating channels\n"); break; } if (!test_bit(cinfo->id, protos)) { channels[num_chans++] = cinfo->id; set_bit(cinfo->id, protos); } } info->raw = scmi_raw_mode_init(&info->handle, info->dbg->top_dentry, info->id, channels, num_chans, info->desc, info->tx_minfo.max_msg); if (IS_ERR(info->raw)) { dev_err(info->dev, "Failed to initialize SCMI RAW Mode !\n"); ret = PTR_ERR(info->raw); info->raw = NULL; } return ret; } static int scmi_probe(struct platform_device *pdev) { int ret; struct scmi_handle *handle; const struct scmi_desc *desc; struct scmi_info *info; bool coex = IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX); struct device *dev = &pdev->dev; struct device_node *child, *np = dev->of_node; desc = of_device_get_match_data(dev); if (!desc) return -EINVAL; info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL); if (!info) return -ENOMEM; info->id = ida_alloc_min(&scmi_id, 0, GFP_KERNEL); if (info->id < 0) return info->id; info->dev = dev; info->desc = desc; info->bus_nb.notifier_call = scmi_bus_notifier; info->dev_req_nb.notifier_call = scmi_device_request_notifier; INIT_LIST_HEAD(&info->node); idr_init(&info->protocols); mutex_init(&info->protocols_mtx); idr_init(&info->active_protocols); mutex_init(&info->devreq_mtx); platform_set_drvdata(pdev, info); idr_init(&info->tx_idr); idr_init(&info->rx_idr); handle = &info->handle; handle->dev = info->dev; handle->version = &info->version; handle->devm_protocol_acquire = scmi_devm_protocol_acquire; handle->devm_protocol_get = scmi_devm_protocol_get; handle->devm_protocol_put = scmi_devm_protocol_put; /* System wide atomic threshold for atomic ops .. if any */ if (!of_property_read_u32(np, "atomic-threshold-us", &info->atomic_threshold)) dev_info(dev, "SCMI System wide atomic threshold set to %d us\n", info->atomic_threshold); handle->is_transport_atomic = scmi_is_transport_atomic; if (desc->ops->link_supplier) { ret = desc->ops->link_supplier(dev); if (ret) goto clear_ida; } /* Setup all channels described in the DT at first */ ret = scmi_channels_setup(info); if (ret) goto clear_ida; ret = bus_register_notifier(&scmi_bus_type, &info->bus_nb); if (ret) goto clear_txrx_setup; ret = blocking_notifier_chain_register(&scmi_requested_devices_nh, &info->dev_req_nb); if (ret) goto clear_bus_notifier; ret = scmi_xfer_info_init(info); if (ret) goto clear_dev_req_notifier; if (scmi_top_dentry) { info->dbg = scmi_debugfs_common_setup(info); if (!info->dbg) dev_warn(dev, "Failed to setup SCMI debugfs.\n"); if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { ret = scmi_debugfs_raw_mode_setup(info); if (!coex) { if (ret) goto clear_dev_req_notifier; /* Bail out anyway when coex disabled. */ return 0; } /* Coex enabled, carry on in any case. */ dev_info(dev, "SCMI RAW Mode COEX enabled !\n"); } } if (scmi_notification_init(handle)) dev_err(dev, "SCMI Notifications NOT available.\n"); if (info->desc->atomic_enabled && !is_transport_polling_capable(info->desc)) dev_err(dev, "Transport is not polling capable. Atomic mode not supported.\n"); /* * Trigger SCMI Base protocol initialization. * It's mandatory and won't be ever released/deinit until the * SCMI stack is shutdown/unloaded as a whole. */ ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE); if (ret) { dev_err(dev, "unable to communicate with SCMI\n"); if (coex) return 0; goto notification_exit; } mutex_lock(&scmi_list_mutex); list_add_tail(&info->node, &scmi_list); mutex_unlock(&scmi_list_mutex); for_each_available_child_of_node(np, child) { u32 prot_id; if (of_property_read_u32(child, "reg", &prot_id)) continue; if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id)) dev_err(dev, "Out of range protocol %d\n", prot_id); if (!scmi_is_protocol_implemented(handle, prot_id)) { dev_err(dev, "SCMI protocol %d not implemented\n", prot_id); continue; } /* * Save this valid DT protocol descriptor amongst * @active_protocols for this SCMI instance/ */ ret = idr_alloc(&info->active_protocols, child, prot_id, prot_id + 1, GFP_KERNEL); if (ret != prot_id) { dev_err(dev, "SCMI protocol %d already activated. Skip\n", prot_id); continue; } of_node_get(child); scmi_create_protocol_devices(child, info, prot_id, NULL); } return 0; notification_exit: if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) scmi_raw_mode_cleanup(info->raw); scmi_notification_exit(&info->handle); clear_dev_req_notifier: blocking_notifier_chain_unregister(&scmi_requested_devices_nh, &info->dev_req_nb); clear_bus_notifier: bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); clear_txrx_setup: scmi_cleanup_txrx_channels(info); clear_ida: ida_free(&scmi_id, info->id); return ret; } static int scmi_remove(struct platform_device *pdev) { int id; struct scmi_info *info = platform_get_drvdata(pdev); struct device_node *child; if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) scmi_raw_mode_cleanup(info->raw); mutex_lock(&scmi_list_mutex); if (info->users) dev_warn(&pdev->dev, "Still active SCMI users will be forcibly unbound.\n"); list_del(&info->node); mutex_unlock(&scmi_list_mutex); scmi_notification_exit(&info->handle); mutex_lock(&info->protocols_mtx); idr_destroy(&info->protocols); mutex_unlock(&info->protocols_mtx); idr_for_each_entry(&info->active_protocols, child, id) of_node_put(child); idr_destroy(&info->active_protocols); blocking_notifier_chain_unregister(&scmi_requested_devices_nh, &info->dev_req_nb); bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); /* Safe to free channels since no more users */ scmi_cleanup_txrx_channels(info); ida_free(&scmi_id, info->id); return 0; } static ssize_t protocol_version_show(struct device *dev, struct device_attribute *attr, char *buf) { struct scmi_info *info = dev_get_drvdata(dev); return sprintf(buf, "%u.%u\n", info->version.major_ver, info->version.minor_ver); } static DEVICE_ATTR_RO(protocol_version); static ssize_t firmware_version_show(struct device *dev, struct device_attribute *attr, char *buf) { struct scmi_info *info = dev_get_drvdata(dev); return sprintf(buf, "0x%x\n", info->version.impl_ver); } static DEVICE_ATTR_RO(firmware_version); static ssize_t vendor_id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct scmi_info *info = dev_get_drvdata(dev); return sprintf(buf, "%s\n", info->version.vendor_id); } static DEVICE_ATTR_RO(vendor_id); static ssize_t sub_vendor_id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct scmi_info *info = dev_get_drvdata(dev); return sprintf(buf, "%s\n", info->version.sub_vendor_id); } static DEVICE_ATTR_RO(sub_vendor_id); static struct attribute *versions_attrs[] = { &dev_attr_firmware_version.attr, &dev_attr_protocol_version.attr, &dev_attr_vendor_id.attr, &dev_attr_sub_vendor_id.attr, NULL, }; ATTRIBUTE_GROUPS(versions); /* Each compatible listed below must have descriptor associated with it */ static const struct of_device_id scmi_of_match[] = { #ifdef CONFIG_ARM_SCMI_TRANSPORT_MAILBOX { .compatible = "arm,scmi", .data = &scmi_mailbox_desc }, #endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_OPTEE { .compatible = "linaro,scmi-optee", .data = &scmi_optee_desc }, #endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_SMC { .compatible = "arm,scmi-smc", .data = &scmi_smc_desc}, { .compatible = "arm,scmi-smc-param", .data = &scmi_smc_desc}, #endif #ifdef CONFIG_ARM_SCMI_TRANSPORT_VIRTIO { .compatible = "arm,scmi-virtio", .data = &scmi_virtio_desc}, #endif { /* Sentinel */ }, }; MODULE_DEVICE_TABLE(of, scmi_of_match); static struct platform_driver scmi_driver = { .driver = { .name = "arm-scmi", .suppress_bind_attrs = true, .of_match_table = scmi_of_match, .dev_groups = versions_groups, }, .probe = scmi_probe, .remove = scmi_remove, }; /** * __scmi_transports_setup - Common helper to call transport-specific * .init/.exit code if provided. * * @init: A flag to distinguish between init and exit. * * Note that, if provided, we invoke .init/.exit functions for all the * transports currently compiled in. * * Return: 0 on Success. */ static inline int __scmi_transports_setup(bool init) { int ret = 0; const struct of_device_id *trans; for (trans = scmi_of_match; trans->data; trans++) { const struct scmi_desc *tdesc = trans->data; if ((init && !tdesc->transport_init) || (!init && !tdesc->transport_exit)) continue; if (init) ret = tdesc->transport_init(); else tdesc->transport_exit(); if (ret) { pr_err("SCMI transport %s FAILED initialization!\n", trans->compatible); break; } } return ret; } static int __init scmi_transports_init(void) { return __scmi_transports_setup(true); } static void __exit scmi_transports_exit(void) { __scmi_transports_setup(false); } static struct dentry *scmi_debugfs_init(void) { struct dentry *d; d = debugfs_create_dir("scmi", NULL); if (IS_ERR(d)) { pr_err("Could NOT create SCMI top dentry.\n"); return NULL; } return d; } static int __init scmi_driver_init(void) { int ret; /* Bail out if no SCMI transport was configured */ if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT))) return -EINVAL; /* Initialize any compiled-in transport which provided an init/exit */ ret = scmi_transports_init(); if (ret) return ret; if (IS_ENABLED(CONFIG_ARM_SCMI_NEED_DEBUGFS)) scmi_top_dentry = scmi_debugfs_init(); scmi_base_register(); scmi_clock_register(); scmi_perf_register(); scmi_power_register(); scmi_reset_register(); scmi_sensors_register(); scmi_voltage_register(); scmi_system_register(); scmi_powercap_register(); return platform_driver_register(&scmi_driver); } module_init(scmi_driver_init); static void __exit scmi_driver_exit(void) { scmi_base_unregister(); scmi_clock_unregister(); scmi_perf_unregister(); scmi_power_unregister(); scmi_reset_unregister(); scmi_sensors_unregister(); scmi_voltage_unregister(); scmi_system_unregister(); scmi_powercap_unregister(); scmi_transports_exit(); platform_driver_unregister(&scmi_driver); debugfs_remove_recursive(scmi_top_dentry); } module_exit(scmi_driver_exit); MODULE_ALIAS("platform:arm-scmi"); MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); MODULE_DESCRIPTION("ARM SCMI protocol driver"); MODULE_LICENSE("GPL v2");
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