diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/driver.c')
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 3102 |
1 files changed, 2823 insertions, 279 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 7483cacf63f9..5caa9191a8d1 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -11,39 +11,45 @@ * various power domain DVFS including the core/cluster, certain system * clocks configuration, thermal sensors and many others. * - * Copyright (C) 2018 ARM Ltd. + * Copyright (C) 2018-2025 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/kmod.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/of.h> +#include <linux/platform_device.h> #include <linux/processor.h> +#include <linux/refcount.h> #include <linux/slab.h> +#include <linux/xarray.h> #include "common.h" +#include "notify.h" +#include "quirks.h" + +#include "raw_mode.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 */ - SCMI_ERR_MAX -}; +#define SCMI_VENDOR_MODULE_ALIAS_FMT "scmi-protocol-0x%02x-%s" + +static DEFINE_IDA(scmi_id); + +static DEFINE_XARRAY(scmi_protocols); /* List of all SCMI devices active in system */ static LIST_HEAD(scmi_list); @@ -52,24 +58,67 @@ 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_block: Preallocated Message array * @xfer_alloc_table: Bitmap table for allocated messages. * Index of this bitmap table is also used for message * sequence identifier. * @xfer_lock: Protection for message allocation + * @max_msg: Maximum number of messages that can be pending + * @free_xfers: A free list for available to use xfers. It is initialized with + * a number of xfers equal to the maximum allowed in-flight + * messages. + * @pending_xfers: An hashtable, indexed by msg_hdr.seq, used to keep all the + * currently in-flight messages. */ struct scmi_xfers_info { - struct scmi_xfer *xfer_block; 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. + * @version: Protocol version supported by the platform as detected at runtime. + * @negotiated_version: When the platform supports a newer protocol version, + * the agent will try to negotiate with the platform the + * usage of the newest version known to it, since + * backward compatibility is NOT automatically assured. + * This field is NON-zero when a successful negotiation + * has completed. + * @ph: An embedded protocol handle that will be passed down to protocol + * initialization code to identify this instance. + * + * Each protocol is initialized independently once for each SCMI platform in + * which is defined by DT and implemented by the SCMI server fw. + */ +struct scmi_protocol_instance { + const struct scmi_handle *handle; + const struct scmi_protocol *proto; + void *gid; + refcount_t users; + void *priv; + unsigned int version; + unsigned int negotiated_version; + 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 * + * @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, @@ -79,12 +128,27 @@ struct scmi_xfers_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 + * 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. + * @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; @@ -93,46 +157,518 @@ struct scmi_info { 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; + 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) - -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 */ +#define tx_minfo_to_scmi_info(h) container_of(h, struct scmi_info, tx_minfo) +#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 void scmi_rx_callback(struct scmi_chan_info *cinfo, + u32 msg_hdr, void *priv); +static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, + u32 msg_hdr, enum scmi_bad_msg err); + +static struct scmi_transport_core_operations scmi_trans_core_ops = { + .bad_message_trace = scmi_bad_message_trace, + .rx_callback = scmi_rx_callback, }; -static inline int scmi_to_linux_errno(int errno) +static unsigned long +scmi_vendor_protocol_signature(unsigned int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) +{ + char *signature, *p; + unsigned long hash = 0; + + /* vendor_id/sub_vendor_id guaranteed <= SCMI_SHORT_NAME_MAX_SIZE */ + signature = kasprintf(GFP_KERNEL, "%02X|%s|%s|0x%08X", protocol_id, + vendor_id ?: "", sub_vendor_id ?: "", impl_ver); + if (!signature) + return 0; + + p = signature; + while (*p) + hash = partial_name_hash(tolower(*p++), hash); + hash = end_name_hash(hash); + + kfree(signature); + + return hash; +} + +static unsigned long +scmi_protocol_key_calculate(int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) { - if (errno < SCMI_SUCCESS && errno > SCMI_ERR_MAX) - return scmi_linux_errmap[-errno]; - return -EIO; + if (protocol_id < SCMI_PROTOCOL_VENDOR_BASE) + return protocol_id; + else + return scmi_vendor_protocol_signature(protocol_id, vendor_id, + sub_vendor_id, impl_ver); } +static const struct scmi_protocol * +__scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) +{ + unsigned long key; + struct scmi_protocol *proto = NULL; + + key = scmi_protocol_key_calculate(protocol_id, vendor_id, + sub_vendor_id, impl_ver); + if (key) + proto = xa_load(&scmi_protocols, key); + + return proto; +} + +static const struct scmi_protocol * +scmi_vendor_protocol_lookup(int protocol_id, char *vendor_id, + char *sub_vendor_id, u32 impl_ver) +{ + const struct scmi_protocol *proto = NULL; + + /* Searching for closest match ...*/ + proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, + sub_vendor_id, impl_ver); + if (proto) + return proto; + + /* Any match just on vendor/sub_vendor ? */ + if (impl_ver) { + proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, + sub_vendor_id, 0); + if (proto) + return proto; + } + + /* Any match just on the vendor ? */ + if (sub_vendor_id) + proto = __scmi_vendor_protocol_lookup(protocol_id, vendor_id, + NULL, 0); + return proto; +} + +static const struct scmi_protocol * +scmi_vendor_protocol_get(int protocol_id, struct scmi_revision_info *version) +{ + const struct scmi_protocol *proto; + + proto = scmi_vendor_protocol_lookup(protocol_id, version->vendor_id, + version->sub_vendor_id, + version->impl_ver); + if (!proto) { + int ret; + + pr_debug("Looking for '" SCMI_VENDOR_MODULE_ALIAS_FMT "'\n", + protocol_id, version->vendor_id); + + /* Note that vendor_id is mandatory for vendor protocols */ + ret = request_module(SCMI_VENDOR_MODULE_ALIAS_FMT, + protocol_id, version->vendor_id); + if (ret) { + pr_warn("Problem loading module for protocol 0x%x\n", + protocol_id); + return NULL; + } + + /* Lookup again, once modules loaded */ + proto = scmi_vendor_protocol_lookup(protocol_id, + version->vendor_id, + version->sub_vendor_id, + version->impl_ver); + } + + if (proto) + pr_info("Loaded SCMI Vendor Protocol 0x%x - %s %s %X\n", + protocol_id, proto->vendor_id ?: "", + proto->sub_vendor_id ?: "", proto->impl_ver); + + return proto; +} + +static const struct scmi_protocol * +scmi_protocol_get(int protocol_id, struct scmi_revision_info *version) +{ + const struct scmi_protocol *proto = NULL; + + if (protocol_id < SCMI_PROTOCOL_VENDOR_BASE) + proto = xa_load(&scmi_protocols, protocol_id); + else + proto = scmi_vendor_protocol_get(protocol_id, version); + + 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(const struct scmi_protocol *proto) +{ + if (proto) + module_put(proto->owner); +} + +static int scmi_vendor_protocol_check(const struct scmi_protocol *proto) +{ + if (!proto->vendor_id) { + pr_err("missing vendor_id for protocol 0x%x\n", proto->id); + return -EINVAL; + } + + if (strlen(proto->vendor_id) >= SCMI_SHORT_NAME_MAX_SIZE) { + pr_err("malformed vendor_id for protocol 0x%x\n", proto->id); + return -EINVAL; + } + + if (proto->sub_vendor_id && + strlen(proto->sub_vendor_id) >= SCMI_SHORT_NAME_MAX_SIZE) { + pr_err("malformed sub_vendor_id for protocol 0x%x\n", + proto->id); + return -EINVAL; + } + + return 0; +} + +int scmi_protocol_register(const struct scmi_protocol *proto) +{ + int ret; + unsigned long key; + + 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; + } + + if (proto->id >= SCMI_PROTOCOL_VENDOR_BASE && + scmi_vendor_protocol_check(proto)) + return -EINVAL; + + /* + * Calculate a protocol key to register this protocol with the core; + * key value 0 is considered invalid. + */ + key = scmi_protocol_key_calculate(proto->id, proto->vendor_id, + proto->sub_vendor_id, + proto->impl_ver); + if (!key) + return -EINVAL; + + ret = xa_insert(&scmi_protocols, key, (void *)proto, GFP_KERNEL); + if (ret) { + pr_err("unable to allocate SCMI protocol slot for 0x%x - err %d\n", + proto->id, ret); + return ret; + } + + pr_debug("Registered SCMI Protocol 0x%x - %s %s 0x%08X\n", + proto->id, proto->vendor_id, proto->sub_vendor_id, + proto->impl_ver); + + return 0; +} +EXPORT_SYMBOL_GPL(scmi_protocol_register); + +void scmi_protocol_unregister(const struct scmi_protocol *proto) +{ + unsigned long key; + + key = scmi_protocol_key_calculate(proto->id, proto->vendor_id, + proto->sub_vendor_id, + proto->impl_ver); + if (!key) + return; + + xa_erase(&scmi_protocols, key); + + pr_debug("Unregistered SCMI Protocol 0x%x\n", proto->id); +} +EXPORT_SYMBOL_GPL(scmi_protocol_unregister); + /** - * scmi_dump_header_dbg() - Helper to dump a message header. + * scmi_create_protocol_devices - Create devices for all pending requests for + * this SCMI instance. * - * @dev: Device pointer corresponding to the SCMI entity - * @hdr: pointer to header. + * @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 inline void scmi_dump_header_dbg(struct device *dev, - struct scmi_msg_hdr *hdr) +static void scmi_create_protocol_devices(struct device_node *np, + struct scmi_info *info, + int prot_id, const char *name) +{ + mutex_lock(&info->devreq_mtx); + scmi_device_create(np, info->dev, 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) { - dev_dbg(dev, "Message ID: %x Sequence ID: %x Protocol: %x\n", - hdr->id, hdr->seq, hdr->protocol_id); + 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) +{ + /* In this context minfo will be tx_minfo due to the xfer pending */ + struct scmi_info *info = tx_minfo_to_scmi_info(minfo); + + /* Set in-flight */ + set_bit(xfer->hdr.seq, minfo->xfer_alloc_table); + hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq); + scmi_inc_count(info->dbg, XFERS_INFLIGHT); + + 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; } /** @@ -144,47 +680,113 @@ static inline void scmi_dump_header_dbg(struct device *dev, * Helper function which is used by various message functions that are * exposed to clients of this driver for allocating a message traffic event. * - * This function can sleep depending on pending requests already in the system - * for the SCMI entity. Further, this also holds a spinlock to maintain - * integrity of internal data structures. + * 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. * - * Return: 0 if all went fine, else corresponding error. + * 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) { - u16 xfer_id; + unsigned long flags; struct scmi_xfer *xfer; - unsigned long flags, bit_pos; - struct scmi_info *info = handle_to_scmi_info(handle); - /* Keep the locked section as small as possible */ spin_lock_irqsave(&minfo->xfer_lock, flags); - bit_pos = find_first_zero_bit(minfo->xfer_alloc_table, - info->desc->max_msg); - if (bit_pos == info->desc->max_msg) { + if (hlist_empty(&minfo->free_xfers)) { spin_unlock_irqrestore(&minfo->xfer_lock, flags); return ERR_PTR(-ENOMEM); } - set_bit(bit_pos, minfo->xfer_alloc_table); - spin_unlock_irqrestore(&minfo->xfer_lock, flags); - xfer_id = bit_pos; + /* grab an xfer from the free_list */ + xfer = hlist_entry(minfo->free_xfers.first, struct scmi_xfer, node); + hlist_del_init(&xfer->node); - xfer = &minfo->xfer_block[xfer_id]; - xfer->hdr.seq = xfer_id; - reinit_completion(&xfer->done); + /* + * 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 @@ -192,91 +794,398 @@ __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) { + struct scmi_info *info = tx_minfo_to_scmi_info(minfo); + + scmi_xfer_token_clear(minfo, xfer); + hash_del(&xfer->node); + xfer->pending = false; + + scmi_dec_count(info->dbg, XFERS_INFLIGHT); + } + xfer->flags = 0; + 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); + + 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_bad_message_trace - A helper to trace weird messages + * + * @cinfo: A reference to the channel descriptor on which the message was + * received + * @msg_hdr: Message header to track + * @err: A specific error code used as a status value in traces. + * + * This helper can be used to trace any kind of weird, incomplete, unexpected, + * timed-out message that arrives and as such, can be traced only referring to + * the header content, since the payload is missing/unreliable. + */ +static void scmi_bad_message_trace(struct scmi_chan_info *cinfo, u32 msg_hdr, + enum scmi_bad_msg err) +{ + char *tag; + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); + + switch (MSG_XTRACT_TYPE(msg_hdr)) { + case MSG_TYPE_COMMAND: + tag = "!RESP"; + break; + case MSG_TYPE_DELAYED_RESP: + tag = "!DLYD"; + break; + case MSG_TYPE_NOTIFICATION: + tag = "!NOTI"; + break; + default: + tag = "!UNKN"; + break; + } + + trace_scmi_msg_dump(info->id, cinfo->id, + MSG_XTRACT_PROT_ID(msg_hdr), + MSG_XTRACT_ID(msg_hdr), tag, + MSG_XTRACT_TOKEN(msg_hdr), err, NULL, 0); +} + +/** + * 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) +{ /* - * Keep the locked section as small as possible - * NOTE: we might escape with smp_mb and no lock here.. - * but just be conservative and symmetric. + * 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); - clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table); + 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); + + scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNEXPECTED); + scmi_inc_count(info->dbg, ERR_MSG_UNEXPECTED); + + 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); + + scmi_bad_message_trace(cinfo, msg_hdr, MSG_INVALID); + scmi_inc_count(info->dbg, ERR_MSG_INVALID); + + /* On error the refcount incremented above has to be dropped */ + __scmi_xfer_put(minfo, xfer); + xfer = ERR_PTR(-EINVAL); + } + + return xfer; } -static void scmi_handle_notification(struct scmi_chan_info *cinfo, u32 msg_hdr) +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 (!cinfo->is_p2a) { + dev_warn(cinfo->dev, "Invalid clear on A2P channel !\n"); + return; + } + + 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)); - info->desc->ops->clear_channel(cinfo); + + scmi_bad_message_trace(cinfo, msg_hdr, MSG_NOMEM); + scmi_inc_count(info->dbg, ERR_MSG_NOMEM); + + scmi_clear_channel(info, cinfo); return; } unpack_scmi_header(msg_hdr, &xfer->hdr); - scmi_dump_header_dbg(dev, &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_inc_count(info->dbg, NOTIFICATION_OK); + + 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); - info->desc->ops->clear_channel(cinfo); + scmi_clear_channel(info, cinfo); } static void scmi_handle_response(struct scmi_chan_info *cinfo, - u16 xfer_id, u8 msg_type) + 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->tx_minfo; - /* Are we even expecting this? */ - if (!test_bit(xfer_id, minfo->xfer_alloc_table)) { - dev_err(dev, "message for %d is not expected!\n", xfer_id); - info->desc->ops->clear_channel(cinfo); - return; - } + 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); - xfer = &minfo->xfer_block[xfer_id]; - /* - * 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 (unlikely(msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done)) { - dev_err(dev, - "Delayed Response for %d not expected! Buggy F/W ?\n", - xfer_id); - info->desc->ops->clear_channel(cinfo); - /* It was unexpected, so nobody will clear the xfer if not us */ - __scmi_xfer_put(minfo, xfer); + if (MSG_XTRACT_TYPE(msg_hdr) == MSG_TYPE_DELAYED_RESP) + scmi_clear_channel(info, cinfo); return; } - scmi_dump_header_dbg(dev, &xfer->hdr); + /* 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, - msg_type); + xfer->hdr.type); - if (msg_type == MSG_TYPE_DELAYED_RESP) { - info->desc->ops->clear_channel(cinfo); + if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) { + scmi_clear_channel(info, cinfo); complete(xfer->async_done); + scmi_inc_count(info->dbg, DELAYED_RESPONSE_OK); } else { complete(&xfer->done); + scmi_inc_count(info->dbg, RESPONSE_OK); + } + + 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 || + xfer->hdr.type == MSG_TYPE_DELAYED_RESP) + scmi_raw_message_report(info->raw, xfer, + SCMI_RAW_REPLY_QUEUE, + cinfo->id); } + + scmi_xfer_command_release(info, xfer); } /** @@ -284,6 +1193,7 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, * * @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. @@ -291,147 +1201,344 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo, * 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) +static void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr, + void *priv) { - u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr); u8 msg_type = MSG_XTRACT_TYPE(msg_hdr); switch (msg_type) { case MSG_TYPE_NOTIFICATION: - scmi_handle_notification(cinfo, msg_hdr); + scmi_handle_notification(cinfo, msg_hdr, priv); break; case MSG_TYPE_COMMAND: case MSG_TYPE_DELAYED_RESP: - scmi_handle_response(cinfo, xfer_id, msg_type); + scmi_handle_response(cinfo, msg_hdr, priv); break; default: WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type); + scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNKNOWN); break; } } /** - * scmi_xfer_put() - Release a transmit message + * xfer_put() - Release a transmit message * - * @handle: Pointer to SCMI entity handle - * @xfer: message that was reserved by scmi_xfer_get + * @ph: Pointer to SCMI protocol handle + * @xfer: message that was reserved by xfer_get_init */ -void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) +static void xfer_put(const struct scmi_protocol_handle *ph, + struct scmi_xfer *xfer) { - struct scmi_info *info = handle_to_scmi_info(handle); + 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_xfer *xfer, ktime_t stop, + bool *ooo) { 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) || + (*ooo = 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; + struct scmi_info *info = handle_to_scmi_info(cinfo->handle); + + 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) { + bool ooo = false; + + /* + * 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, &ooo)); + if (!ooo && !info->desc->ops->poll_done(cinfo, xfer)) { + dev_err(dev, + "timed out in resp(caller: %pS) - polling\n", + (void *)_RET_IP_); + ret = -ETIMEDOUT; + scmi_inc_count(info->dbg, XFERS_RESPONSE_POLLED_TIMEOUT); + } + } + + if (!ret) { + 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) { + 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); + scmi_inc_count(info->dbg, RESPONSE_POLLED_OK); + + if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { + 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; + scmi_inc_count(info->dbg, XFERS_RESPONSE_TIMEOUT); + } + } + + return ret; +} + /** - * scmi_do_xfer() - Do one transfer + * scmi_wait_for_message_response - An helper to group all the possible ways of + * waiting for a synchronous message response. * - * @handle: Pointer to SCMI entity handle + * @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. */ -int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer) +static int do_xfer(const struct scmi_protocol_handle *ph, + struct scmi_xfer *xfer) { int ret; - int timeout; - struct scmi_info *info = handle_to_scmi_info(handle); + 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; - cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id); - if (unlikely(!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"); + scmi_inc_count(info->dbg, SENT_FAIL_POLLING_UNSUPPORTED); return -EINVAL; + } + + cinfo = idr_find(&info->tx_idr, pi->proto->id); + if (unlikely(!cinfo)) { + scmi_inc_count(info->dbg, SENT_FAIL_CHANNEL_NOT_FOUND); + 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); + xfer->hdr.poll_completion, + scmi_inflight_count(&info->handle)); + + /* 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); + scmi_inc_count(info->dbg, SENT_FAIL); 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)); + 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); + scmi_inc_count(info->dbg, SENT_OK); - if (ktime_before(ktime_get(), stop)) - info->desc->ops->fetch_response(cinfo, xfer); - 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_wait_for_message_response(cinfo, xfer); + if (!ret && xfer->hdr.status) { ret = scmi_to_linux_errno(xfer->hdr.status); + scmi_inc_count(info->dbg, ERR_PROTOCOL); + } if (info->desc->ops->mark_txdone) - info->desc->ops->mark_txdone(cinfo, ret); + 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, - xfer->hdr.status); + xfer->hdr.protocol_id, xfer->hdr.seq, ret, + scmi_inflight_count(&info->handle)); return ret; } -#define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC) +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; +} /** - * scmi_do_xfer_with_response() - Do one transfer and wait until the delayed + * do_xfer_with_response() - Do one transfer and wait until the delayed * response is received * - * @handle: Pointer to SCMI entity handle + * @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. */ -int scmi_do_xfer_with_response(const struct scmi_handle *handle, - struct scmi_xfer *xfer) +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 = scmi_do_xfer(handle, xfer); - if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout)) - ret = -ETIMEDOUT; + /* + * 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; } /** - * scmi_xfer_get_init() - Allocate and initialise one message for transmit + * xfer_get_init() - Allocate and initialise one message for transmit * - * @handle: Pointer to SCMI entity handle + * @ph: Pointer to SCMI protocol handle * @msg_id: Message identifier - * @prot_id: Protocol identifier for the message * @tx_size: transmit message size * @rx_size: receive message size * @p: pointer to the allocated and initialised message @@ -442,12 +1549,14 @@ int scmi_do_xfer_with_response(const struct scmi_handle *handle, * Return: 0 if all went fine with @p pointing to message, else * corresponding error. */ -int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, - size_t tx_size, size_t rx_size, struct scmi_xfer **p) +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; - struct scmi_info *info = handle_to_scmi_info(handle); + 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; @@ -456,17 +1565,26 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, tx_size > info->desc->max_msg_size) return -ERANGE; - xfer = scmi_xfer_get(handle, minfo); + 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.protocol_id = prot_id; xfer->hdr.poll_completion = false; *p = xfer; @@ -475,42 +1593,722 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, } /** - * scmi_version_get() - command to get the revision of the SCMI entity + * version_get() - command to get the revision of the SCMI entity * - * @handle: Pointer to SCMI entity handle - * @protocol: Protocol identifier for the message + * @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. */ -int scmi_version_get(const struct scmi_handle *handle, u8 protocol, - u32 *version) +static int version_get(const struct scmi_protocol_handle *ph, u32 *version) { int ret; __le32 *rev_info; struct scmi_xfer *t; - ret = scmi_xfer_get_init(handle, PROTOCOL_VERSION, protocol, 0, - sizeof(*version), &t); + ret = xfer_get_init(ph, PROTOCOL_VERSION, 0, sizeof(*version), &t); if (ret) return ret; - ret = scmi_do_xfer(handle, t); + ret = do_xfer(ph, t); if (!ret) { rev_info = t->rx.buf; *version = le32_to_cpu(*rev_info); } - scmi_xfer_put(handle, t); + xfer_put(ph, t); return ret; } -void scmi_setup_protocol_implemented(const struct scmi_handle *handle, - u8 *prot_imp) +/** + * scmi_set_protocol_priv - Set protocol specific data at init time + * + * @ph: A reference to the protocol handle. + * @priv: The private data to set. + * @version: The detected protocol version for the core to register. + * + * Return: 0 on Success + */ +static int scmi_set_protocol_priv(const struct scmi_protocol_handle *ph, + void *priv, u32 version) +{ + struct scmi_protocol_instance *pi = ph_to_pi(ph); + + pi->priv = priv; + pi->version = version; + + 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. + * @flags: A pointer to specific flags to use, if any. + * @name: A pointer to the preallocated area where the retrieved name will be + * stored as a NULL terminated string. + * @len: The len in bytes of the @name char array. + * + * Return: 0 on Succcess + */ +static int scmi_common_extended_name_get(const struct scmi_protocol_handle *ph, + u8 cmd_id, u32 res_id, u32 *flags, + char *name, size_t len) +{ + int ret; + size_t txlen; + struct scmi_xfer *t; + struct scmi_msg_resp_domain_name_get *resp; + + txlen = !flags ? sizeof(res_id) : sizeof(res_id) + sizeof(*flags); + ret = ph->xops->xfer_get_init(ph, cmd_id, txlen, sizeof(*resp), &t); + if (ret) + goto out; + + put_unaligned_le32(res_id, t->tx.buf); + if (flags) + put_unaligned_le32(*flags, t->tx.buf + sizeof(res_id)); + 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; +} + +/** + * scmi_common_get_max_msg_size - Get maximum message size + * @ph: A protocol handle reference. + * + * Return: Maximum message size for the current protocol. + */ +static int scmi_common_get_max_msg_size(const struct scmi_protocol_handle *ph) +{ + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); + + return info->desc->max_msg_size; +} + +/** + * scmi_protocol_msg_check - Check protocol message attributes + * + * @ph: A reference to the protocol handle. + * @message_id: The ID of the message to check. + * @attributes: A parameter to optionally return the retrieved message + * attributes, in case of Success. + * + * An helper to check protocol message attributes for a specific protocol + * and message pair. + * + * Return: 0 on SUCCESS + */ +static int scmi_protocol_msg_check(const struct scmi_protocol_handle *ph, + u32 message_id, u32 *attributes) +{ + int ret; + struct scmi_xfer *t; + + ret = xfer_get_init(ph, PROTOCOL_MESSAGE_ATTRIBUTES, + sizeof(__le32), 0, &t); + if (ret) + return ret; + + put_unaligned_le32(message_id, t->tx.buf); + ret = do_xfer(ph, t); + if (!ret && attributes) + *attributes = get_unaligned_le32(t->rx.buf); + xfer_put(ph, t); + + 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; +}; + +#define QUIRK_PERF_FC_FORCE \ + ({ \ + if (pi->proto->id == SCMI_PROTOCOL_PERF && \ + message_id == 0x8 /* PERF_LEVEL_GET */) \ + attributes |= BIT(0); \ + }) + +static void +scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph, + u8 describe_id, u32 message_id, u32 valid_size, + u32 domain, void __iomem **p_addr, + struct scmi_fc_db_info **p_db, u32 *rate_limit) +{ + int ret; + u32 flags; + u64 phys_addr; + u32 attributes; + 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); + + /* Check if the MSG_ID supports fastchannel */ + ret = scmi_protocol_msg_check(ph, message_id, &attributes); + SCMI_QUIRK(perf_level_get_fc_force, QUIRK_PERF_FC_FORCE); + if (ret || !MSG_SUPPORTS_FASTCHANNEL(attributes)) { + dev_dbg(ph->dev, + "Skip FC init for 0x%02X/%d domain:%d - ret:%d\n", + pi->proto->id, message_id, domain, ret); + return; + } + + 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; + } + + if (rate_limit) + *rate_limit = le32_to_cpu(resp->rate_limit) & GENMASK(19, 0); + + 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 */ + SCMI_PROTO_FC_RING_DB(64); +} + +static const struct scmi_proto_helpers_ops helpers_ops = { + .extended_name_get = scmi_common_extended_name_get, + .get_max_msg_size = scmi_common_get_max_msg_size, + .iter_response_init = scmi_iterator_init, + .iter_response_run = scmi_iterator_run, + .protocol_msg_check = scmi_protocol_msg_check, + .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_protocol_version_negotiate - Negotiate protocol version + * + * @ph: A reference to the protocol handle. + * + * An helper to negotiate a protocol version different from the latest + * advertised as supported from the platform: on Success backward + * compatibility is assured by the platform. + * + * Return: 0 on Success + */ +static int scmi_protocol_version_negotiate(struct scmi_protocol_handle *ph) +{ + int ret; + struct scmi_xfer *t; + struct scmi_protocol_instance *pi = ph_to_pi(ph); + + /* At first check if NEGOTIATE_PROTOCOL_VERSION is supported ... */ + ret = scmi_protocol_msg_check(ph, NEGOTIATE_PROTOCOL_VERSION, NULL); + if (ret) + return ret; + + /* ... then attempt protocol version negotiation */ + ret = xfer_get_init(ph, NEGOTIATE_PROTOCOL_VERSION, + sizeof(__le32), 0, &t); + if (ret) + return ret; + + put_unaligned_le32(pi->proto->supported_version, t->tx.buf); + ret = do_xfer(ph, t); + if (!ret) + pi->negotiated_version = pi->proto->supported_version; + + xfer_put(ph, t); + + return ret; +} + +/** + * 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); + 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); + + if (pi->version > proto->supported_version) { + ret = scmi_protocol_version_negotiate(&pi->ph); + if (!ret) { + dev_info(handle->dev, + "Protocol 0x%X successfully negotiated version 0x%X\n", + proto->id, pi->negotiated_version); + } else { + dev_warn(handle->dev, + "Detected UNSUPPORTED higher version 0x%X for protocol 0x%X.\n", + pi->version, pi->proto->id); + dev_warn(handle->dev, + "Trying version 0x%X. Backward compatibility is NOT assured.\n", + pi->proto->supported_version); + } + } + + return pi; + +clean: + /* Take care to put the protocol module's owner before releasing all */ + scmi_protocol_put(proto); + 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, &info->version); + 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(pi->proto); + + 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; } @@ -520,16 +2318,169 @@ 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 < MAX_PROTOCOLS_IMP; i++) + 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->desc->atomic_threshold; + + return ret; +} + /** * scmi_handle_get() - Get the SCMI handle for a device * @@ -541,7 +2492,7 @@ scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) * * Return: pointer to handle if successful, NULL on error */ -struct scmi_handle *scmi_handle_get(struct device *dev) +static struct scmi_handle *scmi_handle_get(struct device *dev) { struct list_head *p; struct scmi_info *info; @@ -551,8 +2502,8 @@ struct scmi_handle *scmi_handle_get(struct device *dev) list_for_each(p, &scmi_list) { info = list_entry(p, struct scmi_info, node); if (dev->parent == info->dev) { - handle = &info->handle; info->users++; + handle = &info->handle; break; } } @@ -573,7 +2524,7 @@ struct scmi_handle *scmi_handle_get(struct device *dev) * Return: 0 is successfully released * if null was passed, it returns -EINVAL; */ -int scmi_handle_put(const struct scmi_handle *handle) +static int scmi_handle_put(const struct scmi_handle *handle) { struct scmi_info *info; @@ -589,6 +2540,23 @@ int scmi_handle_put(const struct scmi_handle *handle) 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) { @@ -598,24 +2566,32 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, const struct scmi_desc *desc = sinfo->desc; /* Pre-allocated messages, no more than what hdr.seq can support */ - if (WARN_ON(desc->max_msg >= MSG_TOKEN_MAX)) { - dev_err(dev, "Maximum message of %d exceeds supported %ld\n", - desc->max_msg, MSG_TOKEN_MAX); + 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; } - info->xfer_block = devm_kcalloc(dev, desc->max_msg, - sizeof(*info->xfer_block), GFP_KERNEL); - if (!info->xfer_block) - return -ENOMEM; + hash_init(info->pending_xfers); - info->xfer_alloc_table = devm_kcalloc(dev, BITS_TO_LONGS(desc->max_msg), - sizeof(long), GFP_KERNEL); + /* 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; - /* Pre-initialize the buffer pointer to pre-allocated buffers */ - for (i = 0, xfer = info->xfer_block; i < desc->max_msg; i++, xfer++) { + /* + * 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) @@ -623,6 +2599,10 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, 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); @@ -630,33 +2610,60 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, 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 = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo); + int ret; - if (!ret && idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE)) + 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 *dev, +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; - /* 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)) { + 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; @@ -667,16 +2674,54 @@ static int scmi_chan_setup(struct scmi_info *info, struct device *dev, if (!cinfo) return -ENOMEM; - cinfo->dev = dev; + cinfo->is_p2a = !tx; + cinfo->rx_timeout_ms = info->desc->max_rx_timeout_ms; + cinfo->max_msg_size = info->desc->max_msg_size; + + /* 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) + 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(dev, "unable to allocate SCMI idr slot err %d\n", ret); + 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; } @@ -685,93 +2730,430 @@ idr_alloc: } static inline int -scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) +scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node, + int prot_id) { - int ret = scmi_chan_setup(info, dev, prot_id, true); + 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; + } - if (!ret) /* Rx is optional, hence no error check */ - scmi_chan_setup(info, dev, prot_id, false); + if (ret) + dev_err(info->dev, + "failed to setup channel for protocol:0x%X\n", prot_id); return ret; } -static inline void -scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, - int prot_id, const char *name) +/** + * 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) { - struct scmi_device *sdev; + int ret; + struct device_node *top_np = info->dev->of_node; - 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; + /* 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_scoped(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) + return ret; } - if (scmi_txrx_setup(info, &sdev->dev, prot_id)) { - dev_err(&sdev->dev, "failed to setup transport\n"); - scmi_device_destroy(sdev); - return; + 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 devices of different SCMI instances */ + if (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; } - /* setup handle now as the transport is ready */ - scmi_set_handle(sdev); + 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; } -#define MAX_SCMI_DEV_PER_PROTOCOL 2 -struct scmi_prot_devnames { - int protocol_id; - char *names[MAX_SCMI_DEV_PER_PROTOCOL]; +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 const char * const dbg_counter_strs[] = { + "sent_ok", + "sent_fail", + "sent_fail_polling_unsupported", + "sent_fail_channel_not_found", + "response_ok", + "notification_ok", + "delayed_response_ok", + "xfers_response_timeout", + "xfers_response_polled_timeout", + "response_polled_ok", + "err_msg_unexpected", + "err_msg_invalid", + "err_msg_nomem", + "err_protocol", + "xfers_inflight", }; -static struct scmi_prot_devnames devnames[] = { - { SCMI_PROTOCOL_POWER, { "genpd" },}, - { SCMI_PROTOCOL_PERF, { "cpufreq" },}, - { SCMI_PROTOCOL_CLOCK, { "clocks" },}, - { SCMI_PROTOCOL_SENSOR, { "hwmon" },}, - { SCMI_PROTOCOL_RESET, { "reset" },}, +static ssize_t reset_all_on_write(struct file *filp, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct scmi_debug_info *dbg = filp->private_data; + + for (int i = 0; i < SCMI_DEBUG_COUNTERS_LAST; i++) + atomic_set(&dbg->counters[i], 0); + + return count; +} + +static const struct file_operations fops_reset_counts = { + .owner = THIS_MODULE, + .open = simple_open, + .write = reset_all_on_write, }; -static inline void -scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info, - int prot_id) +static void scmi_debugfs_counters_setup(struct scmi_debug_info *dbg, + struct dentry *trans) { - int loop, cnt; + struct dentry *counters; + int idx; - for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) { - if (devnames[loop].protocol_id != prot_id) - continue; + counters = debugfs_create_dir("counters", trans); + + for (idx = 0; idx < SCMI_DEBUG_COUNTERS_LAST; idx++) + debugfs_create_atomic_t(dbg_counter_strs[idx], 0600, counters, + &dbg->counters[idx]); + + debugfs_create_file("reset", 0200, counters, dbg, &fops_reset_counts); +} + +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, + (u32 *)&info->desc->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); + + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) + scmi_debugfs_counters_setup(dbg, trans); - for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) { - const char *name = devnames[loop].names[cnt]; + dbg->top_dentry = top_dentry; - if (name) - scmi_create_protocol_device(np, info, prot_id, - name); + if (devm_add_action_or_reset(info->dev, + 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) = {}; + + /* 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 const struct scmi_desc *scmi_transport_setup(struct device *dev) +{ + struct scmi_transport *trans; + int ret; + + trans = dev_get_platdata(dev); + if (!trans || !trans->supplier || !trans->core_ops) + return NULL; + + if (!device_link_add(dev, trans->supplier, DL_FLAG_AUTOREMOVE_CONSUMER)) { + dev_err(dev, + "Adding link to supplier transport device failed\n"); + return NULL; + } + + /* Provide core transport ops */ + *trans->core_ops = &scmi_trans_core_ops; + + dev_info(dev, "Using %s\n", dev_driver_string(trans->supplier)); + + ret = of_property_read_u32(dev->of_node, "arm,max-rx-timeout-ms", + &trans->desc.max_rx_timeout_ms); + if (ret && ret != -EINVAL) + dev_err(dev, "Malformed arm,max-rx-timeout-ms DT property.\n"); + + ret = of_property_read_u32(dev->of_node, "arm,max-msg-size", + &trans->desc.max_msg_size); + if (ret && ret != -EINVAL) + dev_err(dev, "Malformed arm,max-msg-size DT property.\n"); + + ret = of_property_read_u32(dev->of_node, "arm,max-msg", + &trans->desc.max_msg); + if (ret && ret != -EINVAL) + dev_err(dev, "Malformed arm,max-msg DT property.\n"); + + dev_info(dev, + "SCMI max-rx-timeout: %dms / max-msg-size: %dbytes / max-msg: %d\n", + trans->desc.max_rx_timeout_ms, trans->desc.max_msg_size, + trans->desc.max_msg); + + /* System wide atomic threshold for atomic ops .. if any */ + if (!of_property_read_u32(dev->of_node, "atomic-threshold-us", + &trans->desc.atomic_threshold)) + dev_info(dev, + "SCMI System wide atomic threshold set to %u us\n", + trans->desc.atomic_threshold); + + return &trans->desc; +} + +static void scmi_enable_matching_quirks(struct scmi_info *info) +{ + struct scmi_revision_info *rev = &info->version; + + dev_dbg(info->dev, "Looking for quirks matching: %s/%s/0x%08X\n", + rev->vendor_id, rev->sub_vendor_id, rev->impl_ver); + + /* Enable applicable quirks */ + scmi_quirks_enable(info->dev, rev->vendor_id, + rev->sub_vendor_id, rev->impl_ver); } static int scmi_probe(struct platform_device *pdev) { int ret; + char *err_str = "probe failure\n"; 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; + desc = scmi_transport_setup(dev); + if (!desc) { + err_str = "transport invalid\n"; + ret = -EINVAL; + goto out_err; + } 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); @@ -780,25 +3162,86 @@ static int scmi_probe(struct platform_device *pdev) 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; + handle->is_transport_atomic = scmi_is_transport_atomic; - ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE); - if (ret) - return ret; + /* Setup all channels described in the DT at first */ + ret = scmi_channels_setup(info); + if (ret) { + err_str = "failed to setup channels\n"; + goto clear_ida; + } + + ret = bus_register_notifier(&scmi_bus_type, &info->bus_nb); + if (ret) { + err_str = "failed to register bus notifier\n"; + goto clear_txrx_setup; + } + + ret = blocking_notifier_chain_register(&scmi_requested_devices_nh, + &info->dev_req_nb); + if (ret) { + err_str = "failed to register device notifier\n"; + goto clear_bus_notifier; + } ret = scmi_xfer_info_init(info); - if (ret) - return ret; + if (ret) { + err_str = "failed to init xfers pool\n"; + 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 (info->dbg && IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) { + ret = scmi_debugfs_raw_mode_setup(info); + if (!coex) { + if (ret) + goto clear_dev_req_notifier; - ret = scmi_base_protocol_init(handle); + /* 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(%d)\n", ret); - return ret; + err_str = "unable to communicate with SCMI\n"; + if (coex) { + dev_err(dev, "%s", err_str); + return 0; + } + goto notification_exit; } mutex_lock(&scmi_list_mutex); list_add_tail(&info->node, &scmi_list); mutex_unlock(&scmi_list_mutex); + scmi_enable_matching_quirks(info); + for_each_available_child_of_node(np, child) { u32 prot_id; @@ -814,42 +3257,76 @@ static int scmi_probe(struct platform_device *pdev) continue; } - scmi_create_protocol_devices(child, info, prot_id); + /* + * 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; -} -void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) -{ - idr_remove(idr, id); +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); + +out_err: + return dev_err_probe(dev, ret, "%s", err_str); } -static int scmi_remove(struct platform_device *pdev) +static void scmi_remove(struct platform_device *pdev) { - int ret = 0; + int id; struct scmi_info *info = platform_get_drvdata(pdev); - struct idr *idr = &info->tx_idr; + 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) - ret = -EBUSY; - else - list_del(&info->node); + dev_warn(&pdev->dev, + "Still active SCMI users will be forcibly unbound.\n"); + list_del(&info->node); mutex_unlock(&scmi_list_mutex); - if (ret) - return ret; + scmi_notification_exit(&info->handle); - /* Safe to free channels since no more users */ - ret = idr_for_each(idr, info->desc->ops->chan_free, idr); - idr_destroy(&info->tx_idr); + mutex_lock(&info->protocols_mtx); + idr_destroy(&info->protocols); + mutex_unlock(&info->protocols_mtx); - idr = &info->rx_idr; - ret = idr_for_each(idr, info->desc->ops->chan_free, idr); - idr_destroy(&info->rx_idr); + idr_for_each_entry(&info->active_protocols, child, id) + of_node_put(child); + idr_destroy(&info->active_protocols); - return ret; + 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); } static ssize_t protocol_version_show(struct device *dev, @@ -898,30 +3375,97 @@ static struct attribute *versions_attrs[] = { }; ATTRIBUTE_GROUPS(versions); -/* Each compatible listed below must have descriptor associated with it */ -static const struct of_device_id scmi_of_match[] = { - { .compatible = "arm,scmi", .data = &scmi_mailbox_desc }, -#ifdef CONFIG_ARM_PSCI_FW - { .compatible = "arm,scmi-smc", .data = &scmi_smc_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, + .suppress_bind_attrs = true, .dev_groups = versions_groups, }, .probe = scmi_probe, .remove = scmi_remove, }; -module_platform_driver(scmi_driver); +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; +} + +int scmi_inflight_count(const struct scmi_handle *handle) +{ + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) { + struct scmi_info *info = handle_to_scmi_info(handle); + + if (!info->dbg) + return 0; + + return atomic_read(&info->dbg->counters[XFERS_INFLIGHT]); + } else { + return 0; + } +} + +static int __init scmi_driver_init(void) +{ + scmi_quirks_initialize(); + + /* Bail out if no SCMI transport was configured */ + if (WARN_ON(!IS_ENABLED(CONFIG_ARM_SCMI_HAVE_TRANSPORT))) + return -EINVAL; + + if (IS_ENABLED(CONFIG_ARM_SCMI_HAVE_SHMEM)) + scmi_trans_core_ops.shmem = scmi_shared_mem_operations_get(); + + if (IS_ENABLED(CONFIG_ARM_SCMI_HAVE_MSG)) + scmi_trans_core_ops.msg = scmi_message_operations_get(); + + 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(); + scmi_pinctrl_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_pinctrl_unregister(); + + platform_driver_unregister(&scmi_driver); + + debugfs_remove_recursive(scmi_top_dentry); +} +module_exit(scmi_driver_exit); -MODULE_ALIAS("platform: arm-scmi"); +MODULE_ALIAS("platform:arm-scmi"); MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); MODULE_DESCRIPTION("ARM SCMI protocol driver"); MODULE_LICENSE("GPL v2"); |