| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Cristian Marussi | 3797 | 51.91% | 33 | 48.53% |
| Sudeep Holla | 2975 | 40.67% | 27 | 39.71% |
| Igor Skalkin | 175 | 2.39% | 2 | 2.94% |
| Rishabh Bhatnagar | 112 | 1.53% | 1 | 1.47% |
| Viresh Kumar | 103 | 1.41% | 1 | 1.47% |
| Lukasz Luba | 98 | 1.34% | 1 | 1.47% |
| Peter Hilber | 28 | 0.38% | 1 | 1.47% |
| Peng Fan | 17 | 0.23% | 1 | 1.47% |
| Aditya Pakki | 10 | 0.14% | 1 | 1.47% |
| Total | 7315 | 68 |
// 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. */ #include <linux/bitmap.h> #include <linux/device.h> #include <linux/export.h> #include <linux/idr.h> #include <linux/io.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" #define CREATE_TRACE_POINTS #include <trace/events/scmi.h> enum scmi_error_codes { SCMI_SUCCESS = 0, /* Success */ SCMI_ERR_SUPPORT = -1, /* Not supported */ SCMI_ERR_PARAMS = -2, /* Invalid Parameters */ SCMI_ERR_ACCESS = -3, /* Invalid access/permission denied */ SCMI_ERR_ENTRY = -4, /* Not found */ SCMI_ERR_RANGE = -5, /* Value out of range */ SCMI_ERR_BUSY = -6, /* Device busy */ SCMI_ERR_COMMS = -7, /* Communication Error */ SCMI_ERR_GENERIC = -8, /* Generic Error */ SCMI_ERR_HARDWARE = -9, /* Hardware Error */ SCMI_ERR_PROTOCOL = -10,/* Protocol Error */ }; /* 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 DEFINE_IDR(scmi_requested_devices); static DEFINE_MUTEX(scmi_requested_devices_mtx); struct scmi_requested_dev { const struct scmi_device_id *id_table; struct list_head node; }; /** * 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_info - Structure representing a SCMI 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 * MAX_PROTOCOLS_IMP 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. * @notify_priv: Pointer to private data structure specific to notifications. * @node: List head * @users: Number of users of this instance */ struct scmi_info { 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; void *notify_priv; struct list_head node; int users; }; #define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle) static const int scmi_linux_errmap[] = { /* better than switch case as long as return value is continuous */ 0, /* SCMI_SUCCESS */ -EOPNOTSUPP, /* SCMI_ERR_SUPPORT */ -EINVAL, /* SCMI_ERR_PARAM */ -EACCES, /* SCMI_ERR_ACCESS */ -ENOENT, /* SCMI_ERR_ENTRY */ -ERANGE, /* SCMI_ERR_RANGE */ -EBUSY, /* SCMI_ERR_BUSY */ -ECOMM, /* SCMI_ERR_COMMS */ -EIO, /* SCMI_ERR_GENERIC */ -EREMOTEIO, /* SCMI_ERR_HARDWARE */ -EPROTO, /* SCMI_ERR_PROTOCOL */ }; static inline int scmi_to_linux_errno(int errno) { int err_idx = -errno; if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap)) return scmi_linux_errmap[err_idx]; return -EIO; } 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); /* Set in-flight */ set_bit(xfer_id, minfo->xfer_alloc_table); 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_get() - Allocate one message * * @handle: Pointer to SCMI entity handle * @minfo: Pointer to Tx/Rx Message management info based on channel type * @set_pending: If true a monotonic token is picked and the xfer is added to * the pending hash table. * * 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, if * required, sets a monotonically increasing token and stores the inflight xfer * into the @pending_xfers hashtable for later retrieval. * * The successfully initialized xfer is refcounted. * * Context: Holds @xfer_lock while manipulating @xfer_alloc_table and * @free_xfers. * * Return: 0 if all went fine, else corresponding error. */ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle, struct scmi_xfers_info *minfo, bool set_pending) { int ret; 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); if (set_pending) { /* Pick and set monotonic token */ ret = scmi_xfer_token_set(minfo, xfer); if (!ret) { hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq); xfer->pending = true; } else { dev_err(handle->dev, "Failed to get monotonic token %d\n", ret); hlist_add_head(&xfer->node, &minfo->free_xfers); xfer = ERR_PTR(ret); } } if (!IS_ERR(xfer)) { refcount_set(&xfer->users, 1); atomic_set(&xfer->busy, SCMI_XFER_FREE); } spin_unlock_irqrestore(&minfo->xfer_lock, flags); return xfer; } /** * __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_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, false); 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) xfer->priv = priv; info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size, xfer); 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); __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)) { 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) xfer->priv = priv; info->desc->ops->fetch_response(cinfo, xfer); 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); } 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); } #define SCMI_MAX_POLL_TO_NS (100 * NSEC_PER_USEC) 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); } /** * 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; int timeout; 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; if (xfer->hdr.poll_completion && !info->desc->ops->poll_done) { dev_warn_once(dev, "Polling mode is not supported by transport.\n"); return -EINVAL; } /* * 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); cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id); if (unlikely(!cinfo)) return -EINVAL; trace_scmi_xfer_begin(xfer->transfer_id, xfer->hdr.id, xfer->hdr.protocol_id, xfer->hdr.seq, xfer->hdr.poll_completion); 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; } if (xfer->hdr.poll_completion) { ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS); spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop)); if (ktime_before(ktime_get(), stop)) { unsigned long flags; /* * 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) { info->desc->ops->fetch_response(cinfo, xfer); xfer->state = SCMI_XFER_RESP_OK; } spin_unlock_irqrestore(&xfer->lock, flags); } else { ret = -ETIMEDOUT; } } else { /* And we wait for the response. */ timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms); if (!wait_for_completion_timeout(&xfer->done, timeout)) { dev_err(dev, "timed out in resp(caller: %pS)\n", (void *)_RET_IP_); ret = -ETIMEDOUT; } } 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); 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; } #define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC) /** * 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 * * 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; ret = do_xfer(ph, xfer); if (!ret) { if (!wait_for_completion_timeout(xfer->async_done, timeout)) 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, true); if (IS_ERR(xfer)) { ret = PTR_ERR(xfer); dev_err(dev, "failed to get free message slot(%d)\n", ret); 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, }; /** * 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.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); if (!info->protocols_imp) return false; for (i = 0; i < MAX_PROTOCOLS_IMP; 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); } /** * 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; struct scmi_protocol_devres *dres; struct scmi_handle *handle = sdev->handle; if (!ph) return ERR_PTR(-EINVAL); dres = devres_alloc(scmi_devm_release_protocol, sizeof(*dres), GFP_KERNEL); if (!dres) return ERR_PTR(-ENOMEM); pi = scmi_get_protocol_instance(handle, protocol_id); if (IS_ERR(pi)) { devres_free(dres); return pi; } dres->handle = handle; dres->protocol_id = protocol_id; devres_add(&sdev->dev, dres); *ph = &pi->ph; return pi->proto->ops; } 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); } static inline struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info) { info->users++; return &info->handle; } /** * 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 */ 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) { handle = scmi_handle_get_from_info_unlocked(info); 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; */ 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 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_kcalloc(dev, BITS_TO_LONGS(MSG_TOKEN_MAX), sizeof(long), 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_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE)) ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo); return ret; } static int scmi_chan_setup(struct scmi_info *info, struct device *dev, int prot_id, bool tx) { int ret, idx; struct scmi_chan_info *cinfo; struct idr *idr; /* Transmit channel is first entry i.e. index 0 */ idx = tx ? 0 : 1; idr = tx ? &info->tx_idr : &info->rx_idr; /* check if already allocated, used for multiple device per protocol */ cinfo = idr_find(idr, prot_id); if (cinfo) return 0; if (!info->desc->ops->chan_available(dev, 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->dev = dev; ret = info->desc->ops->chan_setup(cinfo, info->dev, tx); if (ret) return ret; idr_alloc: ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL); if (ret != prot_id) { dev_err(dev, "unable to allocate SCMI idr slot err %d\n", ret); return ret; } cinfo->handle = &info->handle; return 0; } static inline int scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) { int ret = scmi_chan_setup(info, dev, prot_id, true); if (!ret) /* Rx is optional, hence no error check */ scmi_chan_setup(info, dev, prot_id, false); return ret; } /** * scmi_get_protocol_device - Helper to get/create an SCMI device. * * @np: A device node representing a valid active protocols for the referred * SCMI instance. * @info: The referred SCMI instance for which we are getting/creating this * device. * @prot_id: The protocol ID. * @name: The device name. * * Referring to the specific SCMI instance identified by @info, this helper * takes care to return a properly initialized device matching the requested * @proto_id and @name: if device was still not existent it is created as a * child of the specified SCMI instance @info and its transport properly * initialized as usual. * * Return: A properly initialized scmi device, NULL otherwise. */ static inline struct scmi_device * scmi_get_protocol_device(struct device_node *np, struct scmi_info *info, int prot_id, const char *name) { struct scmi_device *sdev; /* Already created for this parent SCMI instance ? */ sdev = scmi_child_dev_find(info->dev, prot_id, name); if (sdev) return sdev; pr_debug("Creating SCMI device (%s) for protocol %x\n", name, prot_id); sdev = scmi_device_create(np, info->dev, prot_id, name); if (!sdev) { dev_err(info->dev, "failed to create %d protocol device\n", prot_id); return NULL; } if (scmi_txrx_setup(info, &sdev->dev, prot_id)) { dev_err(&sdev->dev, "failed to setup transport\n"); scmi_device_destroy(sdev); return NULL; } return sdev; } static inline void scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, int prot_id, const char *name) { struct scmi_device *sdev; sdev = scmi_get_protocol_device(np, info, prot_id, name); if (!sdev) return; /* setup handle now as the transport is ready */ scmi_set_handle(sdev); } /** * 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 * * All devices previously requested for this instance (if any) are found and * created by scanning the proper @&scmi_requested_devices entry. */ static void scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info, int prot_id) { struct list_head *phead; mutex_lock(&scmi_requested_devices_mtx); phead = idr_find(&scmi_requested_devices, prot_id); if (phead) { struct scmi_requested_dev *rdev; list_for_each_entry(rdev, phead, node) scmi_create_protocol_device(np, info, prot_id, rdev->id_table->name); } mutex_unlock(&scmi_requested_devices_mtx); } /** * scmi_protocol_device_request - Helper to request a device * * @id_table: A protocol/name pair descriptor for the device to be created. * * This helper let an SCMI driver request specific devices identified by the * @id_table to be created for each active SCMI instance. * * The requested device name MUST NOT be already existent for any protocol; * at first the freshly requested @id_table is annotated in the IDR table * @scmi_requested_devices, then a matching device is created for each already * active SCMI instance. (if any) * * This way the requested device is created straight-away for all the already * initialized(probed) SCMI instances (handles) and it remains also annotated * as pending creation if the requesting SCMI driver was loaded before some * SCMI instance and related transports were available: when such late instance * is probed, its probe will take care to scan the list of pending requested * devices and create those on its own (see @scmi_create_protocol_devices and * its enclosing loop) * * Return: 0 on Success */ int scmi_protocol_device_request(const struct scmi_device_id *id_table) { int ret = 0; unsigned int id = 0; struct list_head *head, *phead = NULL; struct scmi_requested_dev *rdev; struct scmi_info *info; pr_debug("Requesting SCMI device (%s) for protocol %x\n", id_table->name, id_table->protocol_id); /* * Search for the matching protocol rdev list and then search * of any existent equally named device...fails if any duplicate found. */ mutex_lock(&scmi_requested_devices_mtx); idr_for_each_entry(&scmi_requested_devices, head, id) { if (!phead) { /* A list found registered in the IDR is never empty */ rdev = list_first_entry(head, struct scmi_requested_dev, node); if (rdev->id_table->protocol_id == id_table->protocol_id) phead = head; } list_for_each_entry(rdev, head, node) { if (!strcmp(rdev->id_table->name, id_table->name)) { pr_err("Ignoring duplicate request [%d] %s\n", rdev->id_table->protocol_id, rdev->id_table->name); ret = -EINVAL; goto out; } } } /* * No duplicate found for requested id_table, so let's create a new * requested device entry for this new valid request. */ rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); if (!rdev) { ret = -ENOMEM; goto out; } rdev->id_table = id_table; /* * Append the new requested device table descriptor to the head of the * related protocol list, eventually creating such head if not already * there. */ if (!phead) { phead = kzalloc(sizeof(*phead), GFP_KERNEL); if (!phead) { kfree(rdev); ret = -ENOMEM; goto out; } INIT_LIST_HEAD(phead); ret = idr_alloc(&scmi_requested_devices, (void *)phead, id_table->protocol_id, id_table->protocol_id + 1, GFP_KERNEL); if (ret != id_table->protocol_id) { pr_err("Failed to save SCMI device - ret:%d\n", ret); kfree(rdev); kfree(phead); ret = -EINVAL; goto out; } ret = 0; } list_add(&rdev->node, phead); /* * Now effectively create and initialize the requested device for every * already initialized SCMI instance which has registered the requested * protocol as a valid active one: i.e. defined in DT and supported by * current platform FW. */ mutex_lock(&scmi_list_mutex); list_for_each_entry(info, &scmi_list, node) { struct device_node *child; child = idr_find(&info->active_protocols, id_table->protocol_id); if (child) { struct scmi_device *sdev; sdev = scmi_get_protocol_device(child, info, id_table->protocol_id, id_table->name); /* Set handle if not already set: device existed */ if (sdev && !sdev->handle) sdev->handle = scmi_handle_get_from_info_unlocked(info); } else { dev_err(info->dev, "Failed. SCMI protocol %d not active.\n", id_table->protocol_id); } } mutex_unlock(&scmi_list_mutex); out: mutex_unlock(&scmi_requested_devices_mtx); return ret; } /** * scmi_protocol_device_unrequest - Helper to unrequest a device * * @id_table: A protocol/name pair descriptor for the device to be unrequested. * * An helper to let an SCMI driver release its request about devices; note that * devices are created and initialized once the first SCMI driver request them * but they destroyed only on SCMI core unloading/unbinding. * * The current SCMI transport layer uses such devices as internal references and * as such they could be shared as same transport between multiple drivers so * that cannot be safely destroyed till the whole SCMI stack is removed. * (unless adding further burden of refcounting.) */ void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table) { struct list_head *phead; pr_debug("Unrequesting SCMI device (%s) for protocol %x\n", id_table->name, id_table->protocol_id); mutex_lock(&scmi_requested_devices_mtx); phead = idr_find(&scmi_requested_devices, id_table->protocol_id); if (phead) { struct scmi_requested_dev *victim, *tmp; list_for_each_entry_safe(victim, tmp, phead, node) { if (!strcmp(victim->id_table->name, id_table->name)) { list_del(&victim->node); kfree(victim); break; } } if (list_empty(phead)) { idr_remove(&scmi_requested_devices, id_table->protocol_id); kfree(phead); } } mutex_unlock(&scmi_requested_devices_mtx); } static int scmi_cleanup_txrx_channels(struct scmi_info *info) { int ret; struct idr *idr = &info->tx_idr; ret = idr_for_each(idr, info->desc->ops->chan_free, idr); idr_destroy(&info->tx_idr); idr = &info->rx_idr; ret = idr_for_each(idr, info->desc->ops->chan_free, idr); idr_destroy(&info->rx_idr); 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; 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->dev = dev; info->desc = desc; INIT_LIST_HEAD(&info->node); idr_init(&info->protocols); mutex_init(&info->protocols_mtx); idr_init(&info->active_protocols); 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_get = scmi_devm_protocol_get; handle->devm_protocol_put = scmi_devm_protocol_put; if (desc->ops->link_supplier) { ret = desc->ops->link_supplier(dev); if (ret) return ret; } ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE); if (ret) return ret; ret = scmi_xfer_info_init(info); if (ret) goto clear_txrx_setup; if (scmi_notification_init(handle)) dev_err(dev, "SCMI Notifications NOT available.\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"); 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); } return 0; notification_exit: scmi_notification_exit(&info->handle); clear_txrx_setup: scmi_cleanup_txrx_channels(info); return ret; } void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) { idr_remove(idr, id); } static int scmi_remove(struct platform_device *pdev) { int ret = 0, id; struct scmi_info *info = platform_get_drvdata(pdev); struct device_node *child; mutex_lock(&scmi_list_mutex); if (info->users) ret = -EBUSY; else list_del(&info->node); mutex_unlock(&scmi_list_mutex); if (ret) return ret; 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); /* Safe to free channels since no more users */ return scmi_cleanup_txrx_channels(info); } 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_SMC { .compatible = "arm,scmi-smc", .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", .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 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; scmi_bus_init(); /* Initialize any compiled-in transport which provided an init/exit */ ret = scmi_transports_init(); if (ret) return ret; scmi_base_register(); scmi_clock_register(); scmi_perf_register(); scmi_power_register(); scmi_reset_register(); scmi_sensors_register(); scmi_voltage_register(); scmi_system_register(); return platform_driver_register(&scmi_driver); } subsys_initcall(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_bus_exit(); scmi_transports_exit(); platform_driver_unregister(&scmi_driver); } 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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