Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-16 13:34:30 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
linux-next/drivers/firmware/arm_scmi/driver.c
Cristian Marussi 54cf6e786c firmware: arm_scmi: Support vendor protocol modules autoloading 
SCMI vendor protocols namespace is shared amongst all vendors so that there
can be multiple implementation for the same protocol ID by different
vendors, exposing completely different functionalities and used by distinct
SCMI vendor drivers.

For these reasons, at runtime, when some driver asks for a protocol, the
proper implementation to use is chosen based on the SCMI vendor/subvendor/
impl_version data as advertised by the platform SCMI server and gathered
from the SCMI core during stack initialization: this enables proper runtime
selection of vendor protocols even when many different protocols from
different vendors are built into the same image via a common defconfig.

This same selection mechanism works similarly well even when all the vendor
protocols are compiled as loadable modules, as long as all such required
protocol modules have been previously loaded by some other means.

Add support for the automatic loading of vendor protocol modules, based on
protocol/vendor IDs, when an SCMI driver attempts to use such a protocol.

Reported-by: Johan Hovold <johan+linaro@kernel.org>
Closes: https://lore.kernel.org/lkml/ZytnRc94iKUfMYH0@hovoldconsulting.com/
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Message-Id: <20241209164957.1801886-2-cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2024-12-10 10:30:45 +00:00

3443 lines
96 KiB
C
Raw Permalink Blame History

// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface (SCMI) Message Protocol driver
*
* SCMI Message Protocol is used between the System Control Processor(SCP)
* and the Application Processors(AP). The Message Handling Unit(MHU)
* provides a mechanism for inter-processor communication between SCP's
* Cortex M3 and AP.
*
* SCP offers control and management of the core/cluster power states,
* various power domain DVFS including the core/cluster, certain system
* clocks configuration, thermal sensors and many others.
*
* Copyright (C) 2018-2024 ARM Ltd.
*/
#define pr_fmt(fmt) 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.h>
#include <linux/platform_device.h>
#include <linux/processor.h>
#include <linux/refcount.h>
#include <linux/slab.h>
#include <linux/xarray.h>
#include "common.h"
#include "notify.h"
#include "raw_mode.h"
#define CREATE_TRACE_POINTS
#include <trace/events/scmi.h>
#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);
/* Protection for the entire list */
static DEFINE_MUTEX(scmi_list_mutex);
/* Track the unique id for the transfers for debug & profiling purpose */
static atomic_t transfer_last_id;
static struct dentry *scmi_top_dentry;
/**
* struct scmi_xfers_info - Structure to manage transfer information
*
* @xfer_alloc_table: Bitmap table for allocated messages.
* Index of this bitmap table is also used for message
* sequence identifier.
* @xfer_lock: Protection for message allocation
* @max_msg: Maximum number of messages that can be pending
* @free_xfers: A free list for available to use xfers. It is initialized with
* a number of xfers equal to the maximum allowed in-flight
* messages.
* @pending_xfers: An hashtable, indexed by msg_hdr.seq, used to keep all the
* currently in-flight messages.
*/
struct scmi_xfers_info {
unsigned long *xfer_alloc_table;
spinlock_t xfer_lock;
int max_msg;
struct hlist_head free_xfers;
DECLARE_HASHTABLE(pending_xfers, SCMI_PENDING_XFERS_HT_ORDER_SZ);
};
/**
* struct scmi_protocol_instance - Describe an initialized protocol instance.
* @handle: Reference to the SCMI handle associated to this protocol instance.
* @proto: A reference to the protocol descriptor.
* @gid: A reference for per-protocol devres management.
* @users: A refcount to track effective users of this protocol.
* @priv: Reference for optional protocol private data.
* @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_debug_info - Debug common info
* @top_dentry: A reference to the top debugfs dentry
* @name: Name of this SCMI instance
* @type: Type of this SCMI instance
* @is_atomic: Flag to state if the transport of this instance is atomic
* @counters: An array of atomic_c's used for tracking statistics (if enabled)
*/
struct scmi_debug_info {
struct dentry *top_dentry;
const char *name;
const char *type;
bool is_atomic;
atomic_t counters[SCMI_DEBUG_COUNTERS_LAST];
};
/**
* struct scmi_info - Structure representing a SCMI instance
*
* @id: A sequence number starting from zero identifying this instance
* @dev: Device pointer
* @desc: SoC description for this instance
* @version: SCMI revision information containing protocol version,
* implementation version and (sub-)vendor identification.
* @handle: Instance of SCMI handle to send to clients
* @tx_minfo: Universal Transmit Message management info
* @rx_minfo: Universal Receive Message management info
* @tx_idr: IDR object to map protocol id to Tx channel info pointer
* @rx_idr: IDR object to map protocol id to Rx channel info pointer
* @protocols: IDR for protocols' instance descriptors initialized for
* this SCMI instance: populated on protocol's first attempted
* usage.
* @protocols_mtx: A mutex to protect protocols instances initialization.
* @protocols_imp: List of protocols implemented, currently maximum of
* scmi_revision_info.num_protocols elements allocated by the
* base protocol
* @active_protocols: IDR storing device_nodes for protocols actually defined
* in the DT and confirmed as implemented by fw.
* @notify_priv: Pointer to private data structure specific to notifications.
* @node: List head
* @users: Number of users of this instance
* @bus_nb: A notifier to listen for device bind/unbind on the scmi bus
* @dev_req_nb: A notifier to listen for device request/unrequest on the scmi
* bus
* @devreq_mtx: A mutex to serialize device creation for this SCMI instance
* @dbg: A pointer to debugfs related data (if any)
* @raw: An opaque reference handle used by SCMI Raw mode.
*/
struct scmi_info {
int id;
struct device *dev;
const struct scmi_desc *desc;
struct scmi_revision_info version;
struct scmi_handle handle;
struct scmi_xfers_info tx_minfo;
struct scmi_xfers_info rx_minfo;
struct idr tx_idr;
struct idr rx_idr;
struct idr protocols;
/* Ensure mutual exclusive access to protocols instance array */
struct mutex protocols_mtx;
u8 *protocols_imp;
struct idr active_protocols;
void *notify_priv;
struct list_head node;
int users;
struct notifier_block bus_nb;
struct notifier_block dev_req_nb;
/* Serialize device creation process for this instance */
struct mutex devreq_mtx;
struct scmi_debug_info *dbg;
void *raw;
};
#define handle_to_scmi_info(h) container_of(h, struct scmi_info, handle)
#define bus_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, bus_nb)
#define req_nb_to_scmi_info(nb) container_of(nb, struct scmi_info, dev_req_nb)
static 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 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 (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_create_protocol_devices - Create devices for all pending requests for
* this SCMI instance.
*
* @np: The device node describing the protocol
* @info: The SCMI instance descriptor
* @prot_id: The protocol ID
* @name: The optional name of the device to be created: if not provided this
* call will lead to the creation of all the devices currently requested
* for the specified protocol.
*/
static void scmi_create_protocol_devices(struct device_node *np,
struct scmi_info *info,
int prot_id, const char *name)
{
struct scmi_device *sdev;
mutex_lock(&info->devreq_mtx);
sdev = scmi_device_create(np, info->dev, prot_id, name);
if (name && !sdev)
dev_err(info->dev,
"failed to create device for protocol 0x%X (%s)\n",
prot_id, name);
mutex_unlock(&info->devreq_mtx);
}
static void scmi_destroy_protocol_devices(struct scmi_info *info,
int prot_id, const char *name)
{
mutex_lock(&info->devreq_mtx);
scmi_device_destroy(info->dev, prot_id, name);
mutex_unlock(&info->devreq_mtx);
}
void scmi_notification_instance_data_set(const struct scmi_handle *handle,
void *priv)
{
struct scmi_info *info = handle_to_scmi_info(handle);
info->notify_priv = priv;
/* Ensure updated protocol private date are visible */
smp_wmb();
}
void *scmi_notification_instance_data_get(const struct scmi_handle *handle)
{
struct scmi_info *info = handle_to_scmi_info(handle);
/* Ensure protocols_private_data has been updated */
smp_rmb();
return info->notify_priv;
}
/**
* scmi_xfer_token_set - Reserve and set new token for the xfer at hand
*
* @minfo: Pointer to Tx/Rx Message management info based on channel type
* @xfer: The xfer to act upon
*
* Pick the next unused monotonically increasing token and set it into
* xfer->hdr.seq: picking a monotonically increasing value avoids immediate
* reuse of freshly completed or timed-out xfers, thus mitigating the risk
* of incorrect association of a late and expired xfer with a live in-flight
* transaction, both happening to re-use the same token identifier.
*
* Since platform is NOT required to answer our request in-order we should
* account for a few rare but possible scenarios:
*
* - exactly 'next_token' may be NOT available so pick xfer_id >= next_token
* using find_next_zero_bit() starting from candidate next_token bit
*
* - all tokens ahead upto (MSG_TOKEN_ID_MASK - 1) are used in-flight but we
* are plenty of free tokens at start, so try a second pass using
* find_next_zero_bit() and starting from 0.
*
* X = used in-flight
*
* Normal
* ------
*
* |- xfer_id picked
* -----------+----------------------------------------------------------
* | | |X|X|X| | | | | | ... ... ... ... ... ... ... ... ... ... ...|X|X|
* ----------------------------------------------------------------------
* ^
* |- next_token
*
* Out-of-order pending at start
* -----------------------------
*
* |- xfer_id picked, last_token fixed
* -----+----------------------------------------------------------------
* |X|X| | | | |X|X| ... ... ... ... ... ... ... ... ... ... ... ...|X| |
* ----------------------------------------------------------------------
* ^
* |- next_token
*
*
* Out-of-order pending at end
* ---------------------------
*
* |- xfer_id picked, last_token fixed
* -----+----------------------------------------------------------------
* |X|X| | | | |X|X| ... ... ... ... ... ... ... ... ... ... |X|X|X||X|X|
* ----------------------------------------------------------------------
* ^
* |- next_token
*
* Context: Assumes to be called with @xfer_lock already acquired.
*
* Return: 0 on Success or error
*/
static int scmi_xfer_token_set(struct scmi_xfers_info *minfo,
struct scmi_xfer *xfer)
{
unsigned long xfer_id, next_token;
/*
* Pick a candidate monotonic token in range [0, MSG_TOKEN_MAX - 1]
* using the pre-allocated transfer_id as a base.
* Note that the global transfer_id is shared across all message types
* so there could be holes in the allocated set of monotonic sequence
* numbers, but that is going to limit the effectiveness of the
* mitigation only in very rare limit conditions.
*/
next_token = (xfer->transfer_id & (MSG_TOKEN_MAX - 1));
/* Pick the next available xfer_id >= next_token */
xfer_id = find_next_zero_bit(minfo->xfer_alloc_table,
MSG_TOKEN_MAX, next_token);
if (xfer_id == MSG_TOKEN_MAX) {
/*
* After heavily out-of-order responses, there are no free
* tokens ahead, but only at start of xfer_alloc_table so
* try again from the beginning.
*/
xfer_id = find_next_zero_bit(minfo->xfer_alloc_table,
MSG_TOKEN_MAX, 0);
/*
* Something is wrong if we got here since there can be a
* maximum number of (MSG_TOKEN_MAX - 1) in-flight messages
* but we have not found any free token [0, MSG_TOKEN_MAX - 1].
*/
if (WARN_ON_ONCE(xfer_id == MSG_TOKEN_MAX))
return -ENOMEM;
}
/* Update +/- last_token accordingly if we skipped some hole */
if (xfer_id != next_token)
atomic_add((int)(xfer_id - next_token), &transfer_last_id);
xfer->hdr.seq = (u16)xfer_id;
return 0;
}
/**
* scmi_xfer_token_clear - Release the token
*
* @minfo: Pointer to Tx/Rx Message management info based on channel type
* @xfer: The xfer to act upon
*/
static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo,
struct scmi_xfer *xfer)
{
clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
}
/**
* scmi_xfer_inflight_register_unlocked - Register the xfer as in-flight
*
* @xfer: The xfer to register
* @minfo: Pointer to Tx/Rx Message management info based on channel type
*
* Note that this helper assumes that the xfer to be registered as in-flight
* had been built using an xfer sequence number which still corresponds to a
* free slot in the xfer_alloc_table.
*
* Context: Assumes to be called with @xfer_lock already acquired.
*/
static inline void
scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,
struct scmi_xfers_info *minfo)
{
/* Set in-flight */
set_bit(xfer->hdr.seq, minfo->xfer_alloc_table);
hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq);
xfer->pending = true;
}
/**
* scmi_xfer_inflight_register - Try to register an xfer as in-flight
*
* @xfer: The xfer to register
* @minfo: Pointer to Tx/Rx Message management info based on channel type
*
* Note that this helper does NOT assume anything about the sequence number
* that was baked into the provided xfer, so it checks at first if it can
* be mapped to a free slot and fails with an error if another xfer with the
* same sequence number is currently still registered as in-flight.
*
* Return: 0 on Success or -EBUSY if sequence number embedded in the xfer
* could not rbe mapped to a free slot in the xfer_alloc_table.
*/
static int scmi_xfer_inflight_register(struct scmi_xfer *xfer,
struct scmi_xfers_info *minfo)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&minfo->xfer_lock, flags);
if (!test_bit(xfer->hdr.seq, minfo->xfer_alloc_table))
scmi_xfer_inflight_register_unlocked(xfer, minfo);
else
ret = -EBUSY;
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
return ret;
}
/**
* scmi_xfer_raw_inflight_register - An helper to register the given xfer as in
* flight on the TX channel, if possible.
*
* @handle: Pointer to SCMI entity handle
* @xfer: The xfer to register
*
* Return: 0 on Success, error otherwise
*/
int scmi_xfer_raw_inflight_register(const struct scmi_handle *handle,
struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(handle);
return scmi_xfer_inflight_register(xfer, &info->tx_minfo);
}
/**
* scmi_xfer_pending_set - Pick a proper sequence number and mark the xfer
* as pending in-flight
*
* @xfer: The xfer to act upon
* @minfo: Pointer to Tx/Rx Message management info based on channel type
*
* Return: 0 on Success or error otherwise
*/
static inline int scmi_xfer_pending_set(struct scmi_xfer *xfer,
struct scmi_xfers_info *minfo)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&minfo->xfer_lock, flags);
/* Set a new monotonic token as the xfer sequence number */
ret = scmi_xfer_token_set(minfo, xfer);
if (!ret)
scmi_xfer_inflight_register_unlocked(xfer, minfo);
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
return ret;
}
/**
* scmi_xfer_get() - Allocate one message
*
* @handle: Pointer to SCMI entity handle
* @minfo: Pointer to Tx/Rx Message management info based on channel type
*
* Helper function which is used by various message functions that are
* exposed to clients of this driver for allocating a message traffic event.
*
* Picks an xfer from the free list @free_xfers (if any available) and perform
* a basic initialization.
*
* Note that, at this point, still no sequence number is assigned to the
* allocated xfer, nor it is registered as a pending transaction.
*
* The successfully initialized xfer is refcounted.
*
* Context: Holds @xfer_lock while manipulating @free_xfers.
*
* Return: An initialized xfer if all went fine, else pointer error.
*/
static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,
struct scmi_xfers_info *minfo)
{
unsigned long flags;
struct scmi_xfer *xfer;
spin_lock_irqsave(&minfo->xfer_lock, flags);
if (hlist_empty(&minfo->free_xfers)) {
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
return ERR_PTR(-ENOMEM);
}
/* grab an xfer from the free_list */
xfer = hlist_entry(minfo->free_xfers.first, struct scmi_xfer, node);
hlist_del_init(&xfer->node);
/*
* Allocate transfer_id early so that can be used also as base for
* monotonic sequence number generation if needed.
*/
xfer->transfer_id = atomic_inc_return(&transfer_last_id);
refcount_set(&xfer->users, 1);
atomic_set(&xfer->busy, SCMI_XFER_FREE);
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
return xfer;
}
/**
* scmi_xfer_raw_get - Helper to get a bare free xfer from the TX channel
*
* @handle: Pointer to SCMI entity handle
*
* Note that xfer is taken from the TX channel structures.
*
* Return: A valid xfer on Success, or an error-pointer otherwise
*/
struct scmi_xfer *scmi_xfer_raw_get(const struct scmi_handle *handle)
{
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(handle);
xfer = scmi_xfer_get(handle, &info->tx_minfo);
if (!IS_ERR(xfer))
xfer->flags |= SCMI_XFER_FLAG_IS_RAW;
return xfer;
}
/**
* scmi_xfer_raw_channel_get - Helper to get a reference to the proper channel
* to use for a specific protocol_id Raw transaction.
*
* @handle: Pointer to SCMI entity handle
* @protocol_id: Identifier of the protocol
*
* Note that in a regular SCMI stack, usually, a protocol has to be defined in
* the DT to have an associated channel and be usable; but in Raw mode any
* protocol in range is allowed, re-using the Base channel, so as to enable
* fuzzing on any protocol without the need of a fully compiled DT.
*
* Return: A reference to the channel to use, or an ERR_PTR
*/
struct scmi_chan_info *
scmi_xfer_raw_channel_get(const struct scmi_handle *handle, u8 protocol_id)
{
struct scmi_chan_info *cinfo;
struct scmi_info *info = handle_to_scmi_info(handle);
cinfo = idr_find(&info->tx_idr, protocol_id);
if (!cinfo) {
if (protocol_id == SCMI_PROTOCOL_BASE)
return ERR_PTR(-EINVAL);
/* Use Base channel for protocols not defined for DT */
cinfo = idr_find(&info->tx_idr, SCMI_PROTOCOL_BASE);
if (!cinfo)
return ERR_PTR(-EINVAL);
dev_warn_once(handle->dev,
"Using Base channel for protocol 0x%X\n",
protocol_id);
}
return cinfo;
}
/**
* __scmi_xfer_put() - Release a message
*
* @minfo: Pointer to Tx/Rx Message management info based on channel type
* @xfer: message that was reserved by scmi_xfer_get
*
* After refcount check, possibly release an xfer, clearing the token slot,
* removing xfer from @pending_xfers and putting it back into free_xfers.
*
* This holds a spinlock to maintain integrity of internal data structures.
*/
static void
__scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
{
unsigned long flags;
spin_lock_irqsave(&minfo->xfer_lock, flags);
if (refcount_dec_and_test(&xfer->users)) {
if (xfer->pending) {
scmi_xfer_token_clear(minfo, xfer);
hash_del(&xfer->node);
xfer->pending = false;
}
hlist_add_head(&xfer->node, &minfo->free_xfers);
}
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
}
/**
* scmi_xfer_raw_put - Release an xfer that was taken by @scmi_xfer_raw_get
*
* @handle: Pointer to SCMI entity handle
* @xfer: A reference to the xfer to put
*
* Note that as with other xfer_put() handlers the xfer is really effectively
* released only if there are no more users on the system.
*/
void scmi_xfer_raw_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(handle);
xfer->flags &= ~SCMI_XFER_FLAG_IS_RAW;
xfer->flags &= ~SCMI_XFER_FLAG_CHAN_SET;
return __scmi_xfer_put(&info->tx_minfo, xfer);
}
/**
* scmi_xfer_lookup_unlocked - Helper to lookup an xfer_id
*
* @minfo: Pointer to Tx/Rx Message management info based on channel type
* @xfer_id: Token ID to lookup in @pending_xfers
*
* Refcounting is untouched.
*
* Context: Assumes to be called with @xfer_lock already acquired.
*
* Return: A valid xfer on Success or error otherwise
*/
static struct scmi_xfer *
scmi_xfer_lookup_unlocked(struct scmi_xfers_info *minfo, u16 xfer_id)
{
struct scmi_xfer *xfer = NULL;
if (test_bit(xfer_id, minfo->xfer_alloc_table))
xfer = XFER_FIND(minfo->pending_xfers, xfer_id);
return xfer ?: ERR_PTR(-EINVAL);
}
/**
* scmi_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)
{
/*
* Even if a response was indeed expected on this slot at this point,
* a buggy platform could wrongly reply feeding us an unexpected
* delayed response we're not prepared to handle: bail-out safely
* blaming firmware.
*/
if (msg_type == MSG_TYPE_DELAYED_RESP && !xfer->async_done) {
dev_err(cinfo->dev,
"Delayed Response for %d not expected! Buggy F/W ?\n",
xfer->hdr.seq);
return -EINVAL;
}
switch (xfer->state) {
case SCMI_XFER_SENT_OK:
if (msg_type == MSG_TYPE_DELAYED_RESP) {
/*
* Delayed Response expected but delivered earlier.
* Assume message RESPONSE was OK and skip state.
*/
xfer->hdr.status = SCMI_SUCCESS;
xfer->state = SCMI_XFER_RESP_OK;
complete(&xfer->done);
dev_warn(cinfo->dev,
"Received valid OoO Delayed Response for %d\n",
xfer->hdr.seq);
}
break;
case SCMI_XFER_RESP_OK:
if (msg_type != MSG_TYPE_DELAYED_RESP)
return -EINVAL;
break;
case SCMI_XFER_DRESP_OK:
/* No further message expected once in SCMI_XFER_DRESP_OK */
return -EINVAL;
}
return 0;
}
/**
* scmi_xfer_state_update - Update xfer state
*
* @xfer: A reference to the xfer to update
* @msg_type: Type of message being processed.
*
* Note that this message is assumed to have been already successfully validated
* by @scmi_msg_response_validate(), so here we just update the state.
*
* Context: Assumes to be called on an xfer exclusively acquired using the
* busy flag.
*/
static inline void scmi_xfer_state_update(struct scmi_xfer *xfer, u8 msg_type)
{
xfer->hdr.type = msg_type;
/* Unknown command types were already discarded earlier */
if (xfer->hdr.type == MSG_TYPE_COMMAND)
xfer->state = SCMI_XFER_RESP_OK;
else
xfer->state = SCMI_XFER_DRESP_OK;
}
static bool scmi_xfer_acquired(struct scmi_xfer *xfer)
{
int ret;
ret = atomic_cmpxchg(&xfer->busy, SCMI_XFER_FREE, SCMI_XFER_BUSY);
return ret == SCMI_XFER_FREE;
}
/**
* scmi_xfer_command_acquire - Helper to lookup and acquire a command xfer
*
* @cinfo: A reference to the channel descriptor.
* @msg_hdr: A message header to use as lookup key
*
* When a valid xfer is found for the sequence number embedded in the provided
* msg_hdr, reference counting is properly updated and exclusive access to this
* xfer is granted till released with @scmi_xfer_command_release.
*
* Return: A valid @xfer on Success or error otherwise.
*/
static inline struct scmi_xfer *
scmi_xfer_command_acquire(struct scmi_chan_info *cinfo, u32 msg_hdr)
{
int ret;
unsigned long flags;
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct scmi_xfers_info *minfo = &info->tx_minfo;
u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
u16 xfer_id = MSG_XTRACT_TOKEN(msg_hdr);
/* Are we even expecting this? */
spin_lock_irqsave(&minfo->xfer_lock, flags);
xfer = scmi_xfer_lookup_unlocked(minfo, xfer_id);
if (IS_ERR(xfer)) {
dev_err(cinfo->dev,
"Message for %d type %d is not expected!\n",
xfer_id, msg_type);
spin_unlock_irqrestore(&minfo->xfer_lock, flags);
scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNEXPECTED);
scmi_inc_count(info->dbg->counters, 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->counters, 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 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));
scmi_bad_message_trace(cinfo, msg_hdr, MSG_NOMEM);
scmi_inc_count(info->dbg->counters, ERR_MSG_NOMEM);
scmi_clear_channel(info, cinfo);
return;
}
unpack_scmi_header(msg_hdr, &xfer->hdr);
if (priv)
/* Ensure order between xfer->priv store and following ops */
smp_store_mb(xfer->priv, priv);
info->desc->ops->fetch_notification(cinfo, info->desc->max_msg_size,
xfer);
trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id,
xfer->hdr.id, "NOTI", xfer->hdr.seq,
xfer->hdr.status, xfer->rx.buf, xfer->rx.len);
scmi_inc_count(info->dbg->counters, 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);
scmi_clear_channel(info, cinfo);
}
static void scmi_handle_response(struct scmi_chan_info *cinfo,
u32 msg_hdr, void *priv)
{
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
xfer = scmi_xfer_command_acquire(cinfo, msg_hdr);
if (IS_ERR(xfer)) {
if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
scmi_raw_error_report(info->raw, cinfo, msg_hdr, priv);
if (MSG_XTRACT_TYPE(msg_hdr) == MSG_TYPE_DELAYED_RESP)
scmi_clear_channel(info, cinfo);
return;
}
/* rx.len could be shrunk in the sync do_xfer, so reset to maxsz */
if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP)
xfer->rx.len = info->desc->max_msg_size;
if (priv)
/* Ensure order between xfer->priv store and following ops */
smp_store_mb(xfer->priv, priv);
info->desc->ops->fetch_response(cinfo, xfer);
trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id,
xfer->hdr.id,
xfer->hdr.type == MSG_TYPE_DELAYED_RESP ?
(!SCMI_XFER_IS_RAW(xfer) ? "DLYD" : "dlyd") :
(!SCMI_XFER_IS_RAW(xfer) ? "RESP" : "resp"),
xfer->hdr.seq, xfer->hdr.status,
xfer->rx.buf, xfer->rx.len);
trace_scmi_rx_done(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq,
xfer->hdr.type);
if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) {
scmi_clear_channel(info, cinfo);
complete(xfer->async_done);
scmi_inc_count(info->dbg->counters, DELAYED_RESPONSE_OK);
} else {
complete(&xfer->done);
scmi_inc_count(info->dbg->counters, 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)
scmi_raw_message_report(info->raw, xfer,
SCMI_RAW_REPLY_QUEUE,
cinfo->id);
}
scmi_xfer_command_release(info, xfer);
}
/**
* scmi_rx_callback() - callback for receiving messages
*
* @cinfo: SCMI channel info
* @msg_hdr: Message header
* @priv: Transport specific private data.
*
* Processes one received message to appropriate transfer information and
* signals completion of the transfer.
*
* NOTE: This function will be invoked in IRQ context, hence should be
* as optimal as possible.
*/
static void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr,
void *priv)
{
u8 msg_type = MSG_XTRACT_TYPE(msg_hdr);
switch (msg_type) {
case MSG_TYPE_NOTIFICATION:
scmi_handle_notification(cinfo, msg_hdr, priv);
break;
case MSG_TYPE_COMMAND:
case MSG_TYPE_DELAYED_RESP:
scmi_handle_response(cinfo, msg_hdr, priv);
break;
default:
WARN_ONCE(1, "received unknown msg_type:%d\n", msg_type);
scmi_bad_message_trace(cinfo, msg_hdr, MSG_UNKNOWN);
break;
}
}
/**
* xfer_put() - Release a transmit message
*
* @ph: Pointer to SCMI protocol handle
* @xfer: message that was reserved by xfer_get_init
*/
static void xfer_put(const struct scmi_protocol_handle *ph,
struct scmi_xfer *xfer)
{
const struct scmi_protocol_instance *pi = ph_to_pi(ph);
struct scmi_info *info = handle_to_scmi_info(pi->handle);
__scmi_xfer_put(&info->tx_minfo, xfer);
}
static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer, ktime_t stop)
{
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
/*
* Poll also on xfer->done so that polling can be forcibly terminated
* in case of out-of-order receptions of delayed responses
*/
return info->desc->ops->poll_done(cinfo, xfer) ||
try_wait_for_completion(&xfer->done) ||
ktime_after(ktime_get(), stop);
}
static int scmi_wait_for_reply(struct device *dev, const struct scmi_desc *desc,
struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer, unsigned int timeout_ms)
{
int ret = 0;
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) {
/*
* Poll on xfer using transport provided .poll_done();
* assumes no completion interrupt was available.
*/
ktime_t stop = ktime_add_ms(ktime_get(), timeout_ms);
spin_until_cond(scmi_xfer_done_no_timeout(cinfo,
xfer, stop));
if (ktime_after(ktime_get(), stop)) {
dev_err(dev,
"timed out in resp(caller: %pS) - polling\n",
(void *)_RET_IP_);
ret = -ETIMEDOUT;
scmi_inc_count(info->dbg->counters, 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->counters, 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->counters, XFERS_RESPONSE_TIMEOUT);
}
}
return ret;
}
/**
* scmi_wait_for_message_response - An helper to group all the possible ways of
* waiting for a synchronous message response.
*
* @cinfo: SCMI channel info
* @xfer: Reference to the transfer being waited for.
*
* Chooses waiting strategy (sleep-waiting vs busy-waiting) depending on
* configuration flags like xfer->hdr.poll_completion.
*
* Return: 0 on Success, error otherwise.
*/
static int scmi_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer)
{
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct device *dev = info->dev;
trace_scmi_xfer_response_wait(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq,
info->desc->max_rx_timeout_ms,
xfer->hdr.poll_completion);
return scmi_wait_for_reply(dev, info->desc, cinfo, xfer,
info->desc->max_rx_timeout_ms);
}
/**
* scmi_xfer_raw_wait_for_message_response - An helper to wait for a message
* reply to an xfer raw request on a specific channel for the required timeout.
*
* @cinfo: SCMI channel info
* @xfer: Reference to the transfer being waited for.
* @timeout_ms: The maximum timeout in milliseconds
*
* Return: 0 on Success, error otherwise.
*/
int scmi_xfer_raw_wait_for_message_response(struct scmi_chan_info *cinfo,
struct scmi_xfer *xfer,
unsigned int timeout_ms)
{
int ret;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct device *dev = info->dev;
ret = scmi_wait_for_reply(dev, info->desc, cinfo, xfer, timeout_ms);
if (ret)
dev_dbg(dev, "timed out in RAW response - HDR:%08X\n",
pack_scmi_header(&xfer->hdr));
return ret;
}
/**
* do_xfer() - Do one transfer
*
* @ph: Pointer to SCMI protocol handle
* @xfer: Transfer to initiate and wait for response
*
* Return: -ETIMEDOUT in case of no response, if transmit error,
* return corresponding error, else if all goes well,
* return 0.
*/
static int do_xfer(const struct scmi_protocol_handle *ph,
struct scmi_xfer *xfer)
{
int ret;
const struct scmi_protocol_instance *pi = ph_to_pi(ph);
struct scmi_info *info = handle_to_scmi_info(pi->handle);
struct device *dev = info->dev;
struct scmi_chan_info *cinfo;
/* Check for polling request on custom command xfers at first */
if (xfer->hdr.poll_completion &&
!is_transport_polling_capable(info->desc)) {
dev_warn_once(dev,
"Polling mode is not supported by transport.\n");
scmi_inc_count(info->dbg->counters, SENT_FAIL_POLLING_UNSUPPORTED);
return -EINVAL;
}
cinfo = idr_find(&info->tx_idr, pi->proto->id);
if (unlikely(!cinfo)) {
scmi_inc_count(info->dbg->counters, 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);
/* 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->counters, SENT_FAIL);
return ret;
}
trace_scmi_msg_dump(info->id, cinfo->id, xfer->hdr.protocol_id,
xfer->hdr.id, "CMND", xfer->hdr.seq,
xfer->hdr.status, xfer->tx.buf, xfer->tx.len);
scmi_inc_count(info->dbg->counters, SENT_OK);
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->counters, ERR_PROTOCOL);
}
if (info->desc->ops->mark_txdone)
info->desc->ops->mark_txdone(cinfo, ret, xfer);
trace_scmi_xfer_end(xfer->transfer_id, xfer->hdr.id,
xfer->hdr.protocol_id, xfer->hdr.seq, ret);
return ret;
}
static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph,
struct scmi_xfer *xfer)
{
const struct scmi_protocol_instance *pi = ph_to_pi(ph);
struct scmi_info *info = handle_to_scmi_info(pi->handle);
xfer->rx.len = info->desc->max_msg_size;
}
/**
* do_xfer_with_response() - Do one transfer and wait until the delayed
* response is received
*
* @ph: Pointer to SCMI protocol handle
* @xfer: Transfer to initiate and wait for response
*
* Using asynchronous commands in atomic/polling mode should be avoided since
* it could cause long busy-waiting here, so ignore polling for the delayed
* response and WARN if it was requested for this command transaction since
* upper layers should refrain from issuing such kind of requests.
*
* The only other option would have been to refrain from using any asynchronous
* command even if made available, when an atomic transport is detected, and
* instead forcibly use the synchronous version (thing that can be easily
* attained at the protocol layer), but this would also have led to longer
* stalls of the channel for synchronous commands and possibly timeouts.
* (in other words there is usually a good reason if a platform provides an
* asynchronous version of a command and we should prefer to use it...just not
* when using atomic/polling mode)
*
* Return: -ETIMEDOUT in case of no delayed response, if transmit error,
* return corresponding error, else if all goes well, return 0.
*/
static int do_xfer_with_response(const struct scmi_protocol_handle *ph,
struct scmi_xfer *xfer)
{
int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
DECLARE_COMPLETION_ONSTACK(async_response);
xfer->async_done = &async_response;
/*
* Delayed responses should not be polled, so an async command should
* not have been used when requiring an atomic/poll context; WARN and
* perform instead a sleeping wait.
* (Note Async + IgnoreDelayedResponses are sent via do_xfer)
*/
WARN_ON_ONCE(xfer->hdr.poll_completion);
ret = do_xfer(ph, xfer);
if (!ret) {
if (!wait_for_completion_timeout(xfer->async_done, timeout)) {
dev_err(ph->dev,
"timed out in delayed resp(caller: %pS)\n",
(void *)_RET_IP_);
ret = -ETIMEDOUT;
} else if (xfer->hdr.status) {
ret = scmi_to_linux_errno(xfer->hdr.status);
}
}
xfer->async_done = NULL;
return ret;
}
/**
* xfer_get_init() - Allocate and initialise one message for transmit
*
* @ph: Pointer to SCMI protocol handle
* @msg_id: Message identifier
* @tx_size: transmit message size
* @rx_size: receive message size
* @p: pointer to the allocated and initialised message
*
* This function allocates the message using @scmi_xfer_get and
* initialise the header.
*
* Return: 0 if all went fine with @p pointing to message, else
* corresponding error.
*/
static int xfer_get_init(const struct scmi_protocol_handle *ph,
u8 msg_id, size_t tx_size, size_t rx_size,
struct scmi_xfer **p)
{
int ret;
struct scmi_xfer *xfer;
const struct scmi_protocol_instance *pi = ph_to_pi(ph);
struct scmi_info *info = handle_to_scmi_info(pi->handle);
struct scmi_xfers_info *minfo = &info->tx_minfo;
struct device *dev = info->dev;
/* Ensure we have sane transfer sizes */
if (rx_size > info->desc->max_msg_size ||
tx_size > info->desc->max_msg_size)
return -ERANGE;
xfer = scmi_xfer_get(pi->handle, minfo);
if (IS_ERR(xfer)) {
ret = PTR_ERR(xfer);
dev_err(dev, "failed to get free message slot(%d)\n", ret);
return ret;
}
/* Pick a sequence number and register this xfer as in-flight */
ret = scmi_xfer_pending_set(xfer, minfo);
if (ret) {
dev_err(pi->handle->dev,
"Failed to get monotonic token %d\n", ret);
__scmi_xfer_put(minfo, xfer);
return ret;
}
xfer->tx.len = tx_size;
xfer->rx.len = rx_size ? : info->desc->max_msg_size;
xfer->hdr.type = MSG_TYPE_COMMAND;
xfer->hdr.id = msg_id;
xfer->hdr.poll_completion = false;
*p = xfer;
return 0;
}
/**
* version_get() - command to get the revision of the SCMI entity
*
* @ph: Pointer to SCMI protocol handle
* @version: Holds returned version of protocol.
*
* Updates the SCMI information in the internal data structure.
*
* Return: 0 if all went fine, else return appropriate error.
*/
static int version_get(const struct scmi_protocol_handle *ph, u32 *version)
{
int ret;
__le32 *rev_info;
struct scmi_xfer *t;
ret = xfer_get_init(ph, PROTOCOL_VERSION, 0, sizeof(*version), &t);
if (ret)
return ret;
ret = do_xfer(ph, t);
if (!ret) {
rev_info = t->rx.buf;
*version = le32_to_cpu(*rev_info);
}
xfer_put(ph, t);
return ret;
}
/**
* scmi_set_protocol_priv - Set protocol specific data at init time
*
* @ph: A reference to the protocol handle.
* @priv: The private data to set.
* @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;
}
/**
* struct scmi_iterator - Iterator descriptor
* @msg: A reference to the message TX buffer; filled by @prepare_message with
* a proper custom command payload for each multi-part command request.
* @resp: A reference to the response RX buffer; used by @update_state and
* @process_response to parse the multi-part replies.
* @t: A reference to the underlying xfer initialized and used transparently by
* the iterator internal routines.
* @ph: A reference to the associated protocol handle to be used.
* @ops: A reference to the custom provided iterator operations.
* @state: The current iterator state; used and updated in turn by the iterators
* internal routines and by the caller-provided @scmi_iterator_ops.
* @priv: A reference to optional private data as provided by the caller and
* passed back to the @@scmi_iterator_ops.
*/
struct scmi_iterator {
void *msg;
void *resp;
struct scmi_xfer *t;
const struct scmi_protocol_handle *ph;
struct scmi_iterator_ops *ops;
struct scmi_iterator_state state;
void *priv;
};
static void *scmi_iterator_init(const struct scmi_protocol_handle *ph,
struct scmi_iterator_ops *ops,
unsigned int max_resources, u8 msg_id,
size_t tx_size, void *priv)
{
int ret;
struct scmi_iterator *i;
i = devm_kzalloc(ph->dev, sizeof(*i), GFP_KERNEL);
if (!i)
return ERR_PTR(-ENOMEM);
i->ph = ph;
i->ops = ops;
i->priv = priv;
ret = ph->xops->xfer_get_init(ph, msg_id, tx_size, 0, &i->t);
if (ret) {
devm_kfree(ph->dev, i);
return ERR_PTR(ret);
}
i->state.max_resources = max_resources;
i->msg = i->t->tx.buf;
i->resp = i->t->rx.buf;
return i;
}
static int scmi_iterator_run(void *iter)
{
int ret = -EINVAL;
struct scmi_iterator_ops *iops;
const struct scmi_protocol_handle *ph;
struct scmi_iterator_state *st;
struct scmi_iterator *i = iter;
if (!i || !i->ops || !i->ph)
return ret;
iops = i->ops;
ph = i->ph;
st = &i->state;
do {
iops->prepare_message(i->msg, st->desc_index, i->priv);
ret = ph->xops->do_xfer(ph, i->t);
if (ret)
break;
st->rx_len = i->t->rx.len;
ret = iops->update_state(st, i->resp, i->priv);
if (ret)
break;
if (st->num_returned > st->max_resources - st->desc_index) {
dev_err(ph->dev,
"No. of resources can't exceed %d\n",
st->max_resources);
ret = -EINVAL;
break;
}
for (st->loop_idx = 0; st->loop_idx < st->num_returned;
st->loop_idx++) {
ret = iops->process_response(ph, i->resp, st, i->priv);
if (ret)
goto out;
}
st->desc_index += st->num_returned;
ph->xops->reset_rx_to_maxsz(ph, i->t);
/*
* check for both returned and remaining to avoid infinite
* loop due to buggy firmware
*/
} while (st->num_returned && st->num_remaining);
out:
/* Finalize and destroy iterator */
ph->xops->xfer_put(ph, i->t);
devm_kfree(ph->dev, i);
return ret;
}
struct scmi_msg_get_fc_info {
__le32 domain;
__le32 message_id;
};
struct scmi_msg_resp_desc_fc {
__le32 attr;
#define SUPPORTS_DOORBELL(x) ((x) & BIT(0))
#define DOORBELL_REG_WIDTH(x) FIELD_GET(GENMASK(2, 1), (x))
__le32 rate_limit;
__le32 chan_addr_low;
__le32 chan_addr_high;
__le32 chan_size;
__le32 db_addr_low;
__le32 db_addr_high;
__le32 db_set_lmask;
__le32 db_set_hmask;
__le32 db_preserve_lmask;
__le32 db_preserve_hmask;
};
static void
scmi_common_fastchannel_init(const struct scmi_protocol_handle *ph,
u8 describe_id, u32 message_id, u32 valid_size,
u32 domain, void __iomem **p_addr,
struct scmi_fc_db_info **p_db, u32 *rate_limit)
{
int ret;
u32 flags;
u64 phys_addr;
u8 size;
void __iomem *addr;
struct scmi_xfer *t;
struct scmi_fc_db_info *db = NULL;
struct scmi_msg_get_fc_info *info;
struct scmi_msg_resp_desc_fc *resp;
const struct scmi_protocol_instance *pi = ph_to_pi(ph);
if (!p_addr) {
ret = -EINVAL;
goto err_out;
}
ret = ph->xops->xfer_get_init(ph, describe_id,
sizeof(*info), sizeof(*resp), &t);
if (ret)
goto err_out;
info = t->tx.buf;
info->domain = cpu_to_le32(domain);
info->message_id = cpu_to_le32(message_id);
/*
* Bail out on error leaving fc_info addresses zeroed; this includes
* the case in which the requested domain/message_id does NOT support
* fastchannels at all.
*/
ret = ph->xops->do_xfer(ph, t);
if (ret)
goto err_xfer;
resp = t->rx.buf;
flags = le32_to_cpu(resp->attr);
size = le32_to_cpu(resp->chan_size);
if (size != valid_size) {
ret = -EINVAL;
goto err_xfer;
}
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 */
#ifdef CONFIG_64BIT
SCMI_PROTO_FC_RING_DB(64);
#else
{
u64 val = 0;
if (db->mask)
val = ioread64_hi_lo(db->addr) & db->mask;
iowrite64_hi_lo(db->set | val, db->addr);
}
#endif
}
/**
* 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;
}
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;
}
static bool
scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id)
{
int i;
struct scmi_info *info = handle_to_scmi_info(handle);
struct scmi_revision_info *rev = handle->version;
if (!info->protocols_imp)
return false;
for (i = 0; i < rev->num_protocols; i++)
if (info->protocols_imp[i] == prot_id)
return true;
return false;
}
struct scmi_protocol_devres {
const struct scmi_handle *handle;
u8 protocol_id;
};
static void scmi_devm_release_protocol(struct device *dev, void *res)
{
struct scmi_protocol_devres *dres = res;
scmi_protocol_release(dres->handle, dres->protocol_id);
}
static struct scmi_protocol_instance __must_check *
scmi_devres_protocol_instance_get(struct scmi_device *sdev, u8 protocol_id)
{
struct scmi_protocol_instance *pi;
struct scmi_protocol_devres *dres;
dres = devres_alloc(scmi_devm_release_protocol,
sizeof(*dres), GFP_KERNEL);
if (!dres)
return ERR_PTR(-ENOMEM);
pi = scmi_get_protocol_instance(sdev->handle, protocol_id);
if (IS_ERR(pi)) {
devres_free(dres);
return pi;
}
dres->handle = sdev->handle;
dres->protocol_id = protocol_id;
devres_add(&sdev->dev, dres);
return pi;
}
/**
* scmi_devm_protocol_get - Devres managed get protocol operations and handle
* @sdev: A reference to an scmi_device whose embedded struct device is to
* be used for devres accounting.
* @protocol_id: The protocol being requested.
* @ph: A pointer reference used to pass back the associated protocol handle.
*
* Get hold of a protocol accounting for its usage, eventually triggering its
* initialization, and returning the protocol specific operations and related
* protocol handle which will be used as first argument in most of the
* protocols operations methods.
* Being a devres based managed method, protocol hold will be automatically
* released, and possibly de-initialized on last user, once the SCMI driver
* owning the scmi_device is unbound from it.
*
* Return: A reference to the requested protocol operations or error.
* Must be checked for errors by caller.
*/
static const void __must_check *
scmi_devm_protocol_get(struct scmi_device *sdev, u8 protocol_id,
struct scmi_protocol_handle **ph)
{
struct scmi_protocol_instance *pi;
if (!ph)
return ERR_PTR(-EINVAL);
pi = scmi_devres_protocol_instance_get(sdev, protocol_id);
if (IS_ERR(pi))
return pi;
*ph = &pi->ph;
return pi->proto->ops;
}
/**
* scmi_devm_protocol_acquire - Devres managed helper to get hold of a protocol
* @sdev: A reference to an scmi_device whose embedded struct device is to
* be used for devres accounting.
* @protocol_id: The protocol being requested.
*
* Get hold of a protocol accounting for its usage, possibly triggering its
* initialization but without getting access to its protocol specific operations
* and handle.
*
* Being a devres based managed method, protocol hold will be automatically
* released, and possibly de-initialized on last user, once the SCMI driver
* owning the scmi_device is unbound from it.
*
* Return: 0 on SUCCESS
*/
static int __must_check scmi_devm_protocol_acquire(struct scmi_device *sdev,
u8 protocol_id)
{
struct scmi_protocol_instance *pi;
pi = scmi_devres_protocol_instance_get(sdev, protocol_id);
if (IS_ERR(pi))
return PTR_ERR(pi);
return 0;
}
static int scmi_devm_protocol_match(struct device *dev, void *res, void *data)
{
struct scmi_protocol_devres *dres = res;
if (WARN_ON(!dres || !data))
return 0;
return dres->protocol_id == *((u8 *)data);
}
/**
* scmi_devm_protocol_put - Devres managed put protocol operations and handle
* @sdev: A reference to an scmi_device whose embedded struct device is to
* be used for devres accounting.
* @protocol_id: The protocol being requested.
*
* Explicitly release a protocol hold previously obtained calling the above
* @scmi_devm_protocol_get.
*/
static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id)
{
int ret;
ret = devres_release(&sdev->dev, scmi_devm_release_protocol,
scmi_devm_protocol_match, &protocol_id);
WARN_ON(ret);
}
/**
* scmi_is_transport_atomic - Method to check if underlying transport for an
* SCMI instance is configured as atomic.
*
* @handle: A reference to the SCMI platform instance.
* @atomic_threshold: An optional return value for the system wide currently
* configured threshold for atomic operations.
*
* Return: True if transport is configured as atomic
*/
static bool scmi_is_transport_atomic(const struct scmi_handle *handle,
unsigned int *atomic_threshold)
{
bool ret;
struct scmi_info *info = handle_to_scmi_info(handle);
ret = info->desc->atomic_enabled &&
is_transport_polling_capable(info->desc);
if (ret && atomic_threshold)
*atomic_threshold = info->desc->atomic_threshold;
return ret;
}
/**
* scmi_handle_get() - Get the SCMI handle for a device
*
* @dev: pointer to device for which we want SCMI handle
*
* NOTE: The function does not track individual clients of the framework
* and is expected to be maintained by caller of SCMI protocol library.
* scmi_handle_put must be balanced with successful scmi_handle_get
*
* Return: pointer to handle if successful, NULL on error
*/
static struct scmi_handle *scmi_handle_get(struct device *dev)
{
struct list_head *p;
struct scmi_info *info;
struct scmi_handle *handle = NULL;
mutex_lock(&scmi_list_mutex);
list_for_each(p, &scmi_list) {
info = list_entry(p, struct scmi_info, node);
if (dev->parent == info->dev) {
info->users++;
handle = &info->handle;
break;
}
}
mutex_unlock(&scmi_list_mutex);
return handle;
}
/**
* scmi_handle_put() - Release the handle acquired by scmi_handle_get
*
* @handle: handle acquired by scmi_handle_get
*
* NOTE: The function does not track individual clients of the framework
* and is expected to be maintained by caller of SCMI protocol library.
* scmi_handle_put must be balanced with successful scmi_handle_get
*
* Return: 0 is successfully released
* if null was passed, it returns -EINVAL;
*/
static int scmi_handle_put(const struct scmi_handle *handle)
{
struct scmi_info *info;
if (!handle)
return -EINVAL;
info = handle_to_scmi_info(handle);
mutex_lock(&scmi_list_mutex);
if (!WARN_ON(!info->users))
info->users--;
mutex_unlock(&scmi_list_mutex);
return 0;
}
static void scmi_device_link_add(struct device *consumer,
struct device *supplier)
{
struct device_link *link;
link = device_link_add(consumer, supplier, DL_FLAG_AUTOREMOVE_CONSUMER);
WARN_ON(!link);
}
static void scmi_set_handle(struct scmi_device *scmi_dev)
{
scmi_dev->handle = scmi_handle_get(&scmi_dev->dev);
if (scmi_dev->handle)
scmi_device_link_add(&scmi_dev->dev, scmi_dev->handle->dev);
}
static int __scmi_xfer_info_init(struct scmi_info *sinfo,
struct scmi_xfers_info *info)
{
int i;
struct scmi_xfer *xfer;
struct device *dev = sinfo->dev;
const struct scmi_desc *desc = sinfo->desc;
/* Pre-allocated messages, no more than what hdr.seq can support */
if (WARN_ON(!info->max_msg || info->max_msg > MSG_TOKEN_MAX)) {
dev_err(dev,
"Invalid maximum messages %d, not in range [1 - %lu]\n",
info->max_msg, MSG_TOKEN_MAX);
return -EINVAL;
}
hash_init(info->pending_xfers);
/* Allocate a bitmask sized to hold MSG_TOKEN_MAX tokens */
info->xfer_alloc_table = devm_bitmap_zalloc(dev, MSG_TOKEN_MAX,
GFP_KERNEL);
if (!info->xfer_alloc_table)
return -ENOMEM;
/*
* Preallocate a number of xfers equal to max inflight messages,
* pre-initialize the buffer pointer to pre-allocated buffers and
* attach all of them to the free list
*/
INIT_HLIST_HEAD(&info->free_xfers);
for (i = 0; i < info->max_msg; i++) {
xfer = devm_kzalloc(dev, sizeof(*xfer), GFP_KERNEL);
if (!xfer)
return -ENOMEM;
xfer->rx.buf = devm_kcalloc(dev, sizeof(u8), desc->max_msg_size,
GFP_KERNEL);
if (!xfer->rx.buf)
return -ENOMEM;
xfer->tx.buf = xfer->rx.buf;
init_completion(&xfer->done);
spin_lock_init(&xfer->lock);
/* Add initialized xfer to the free list */
hlist_add_head(&xfer->node, &info->free_xfers);
}
spin_lock_init(&info->xfer_lock);
return 0;
}
static int scmi_channels_max_msg_configure(struct scmi_info *sinfo)
{
const struct scmi_desc *desc = sinfo->desc;
if (!desc->ops->get_max_msg) {
sinfo->tx_minfo.max_msg = desc->max_msg;
sinfo->rx_minfo.max_msg = desc->max_msg;
} else {
struct scmi_chan_info *base_cinfo;
base_cinfo = idr_find(&sinfo->tx_idr, SCMI_PROTOCOL_BASE);
if (!base_cinfo)
return -EINVAL;
sinfo->tx_minfo.max_msg = desc->ops->get_max_msg(base_cinfo);
/* RX channel is optional so can be skipped */
base_cinfo = idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE);
if (base_cinfo)
sinfo->rx_minfo.max_msg =
desc->ops->get_max_msg(base_cinfo);
}
return 0;
}
static int scmi_xfer_info_init(struct scmi_info *sinfo)
{
int ret;
ret = scmi_channels_max_msg_configure(sinfo);
if (ret)
return ret;
ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo);
if (!ret && !idr_is_empty(&sinfo->rx_idr))
ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo);
return ret;
}
static int scmi_chan_setup(struct scmi_info *info, struct device_node *of_node,
int prot_id, bool tx)
{
int ret, idx;
char name[32];
struct scmi_chan_info *cinfo;
struct idr *idr;
struct scmi_device *tdev = NULL;
/* Transmit channel is first entry i.e. index 0 */
idx = tx ? 0 : 1;
idr = tx ? &info->tx_idr : &info->rx_idr;
if (!info->desc->ops->chan_available(of_node, idx)) {
cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
return -EINVAL;
goto idr_alloc;
}
cinfo = devm_kzalloc(info->dev, sizeof(*cinfo), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
cinfo->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) {
of_node_put(of_node);
scmi_device_destroy(info->dev, prot_id, name);
devm_kfree(info->dev, cinfo);
return ret;
}
if (tx && is_polling_required(cinfo, info->desc)) {
if (is_transport_polling_capable(info->desc))
dev_info(&tdev->dev,
"Enabled polling mode TX channel - prot_id:%d\n",
prot_id);
else
dev_warn(&tdev->dev,
"Polling mode NOT supported by transport.\n");
}
idr_alloc:
ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
if (ret != prot_id) {
dev_err(info->dev,
"unable to allocate SCMI idr slot err %d\n", ret);
/* Destroy channel and device only if created by this call. */
if (tdev) {
of_node_put(of_node);
scmi_device_destroy(info->dev, prot_id, name);
devm_kfree(info->dev, cinfo);
}
return ret;
}
cinfo->handle = &info->handle;
return 0;
}
static inline int
scmi_txrx_setup(struct scmi_info *info, struct device_node *of_node,
int prot_id)
{
int ret = scmi_chan_setup(info, of_node, prot_id, true);
if (!ret) {
/* Rx is optional, report only memory errors */
ret = scmi_chan_setup(info, of_node, prot_id, false);
if (ret && ret != -ENOMEM)
ret = 0;
}
if (ret)
dev_err(info->dev,
"failed to setup channel for protocol:0x%X\n", prot_id);
return ret;
}
/**
* scmi_channels_setup - Helper to initialize all required channels
*
* @info: The SCMI instance descriptor.
*
* Initialize all the channels found described in the DT against the underlying
* configured transport using custom defined dedicated devices instead of
* borrowing devices from the SCMI drivers; this way channels are initialized
* upfront during core SCMI stack probing and are no more coupled with SCMI
* devices used by SCMI drivers.
*
* Note that, even though a pair of TX/RX channels is associated to each
* protocol defined in the DT, a distinct freshly initialized channel is
* created only if the DT node for the protocol at hand describes a dedicated
* channel: in all the other cases the common BASE protocol channel is reused.
*
* Return: 0 on Success
*/
static int scmi_channels_setup(struct scmi_info *info)
{
int ret;
struct device_node *top_np = info->dev->of_node;
/* Initialize a common generic channel at first */
ret = scmi_txrx_setup(info, top_np, SCMI_PROTOCOL_BASE);
if (ret)
return ret;
for_each_available_child_of_node_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;
}
return 0;
}
static int scmi_chan_destroy(int id, void *p, void *idr)
{
struct scmi_chan_info *cinfo = p;
if (cinfo->dev) {
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
struct scmi_device *sdev = to_scmi_dev(cinfo->dev);
of_node_put(cinfo->dev->of_node);
scmi_device_destroy(info->dev, id, sdev->name);
cinfo->dev = NULL;
}
idr_remove(idr, id);
return 0;
}
static void scmi_cleanup_channels(struct scmi_info *info, struct idr *idr)
{
/* At first free all channels at the transport layer ... */
idr_for_each(idr, info->desc->ops->chan_free, idr);
/* ...then destroy all underlying devices */
idr_for_each(idr, scmi_chan_destroy, idr);
idr_destroy(idr);
}
static void scmi_cleanup_txrx_channels(struct scmi_info *info)
{
scmi_cleanup_channels(info, &info->tx_idr);
scmi_cleanup_channels(info, &info->rx_idr);
}
static int scmi_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct scmi_info *info = bus_nb_to_scmi_info(nb);
struct scmi_device *sdev = to_scmi_dev(data);
/* Skip transport devices and devices of different SCMI instances */
if (!strncmp(sdev->name, "__scmi_transport_device", 23) ||
sdev->dev.parent != info->dev)
return NOTIFY_DONE;
switch (action) {
case BUS_NOTIFY_BIND_DRIVER:
/* setup handle now as the transport is ready */
scmi_set_handle(sdev);
break;
case BUS_NOTIFY_UNBOUND_DRIVER:
scmi_handle_put(sdev->handle);
sdev->handle = NULL;
break;
default:
return NOTIFY_DONE;
}
dev_dbg(info->dev, "Device %s (%s) is now %s\n", dev_name(&sdev->dev),
sdev->name, action == BUS_NOTIFY_BIND_DRIVER ?
"about to be BOUND." : "UNBOUND.");
return NOTIFY_OK;
}
static int scmi_device_request_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device_node *np;
struct scmi_device_id *id_table = data;
struct scmi_info *info = req_nb_to_scmi_info(nb);
np = idr_find(&info->active_protocols, id_table->protocol_id);
if (!np)
return NOTIFY_DONE;
dev_dbg(info->dev, "%sRequested device (%s) for protocol 0x%x\n",
action == SCMI_BUS_NOTIFY_DEVICE_REQUEST ? "" : "UN-",
id_table->name, id_table->protocol_id);
switch (action) {
case SCMI_BUS_NOTIFY_DEVICE_REQUEST:
scmi_create_protocol_devices(np, info, id_table->protocol_id,
id_table->name);
break;
case SCMI_BUS_NOTIFY_DEVICE_UNREQUEST:
scmi_destroy_protocol_devices(info, id_table->protocol_id,
id_table->name);
break;
default:
return NOTIFY_DONE;
}
return NOTIFY_OK;
}
static 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",
};
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 void scmi_debugfs_counters_setup(struct scmi_debug_info *dbg,
struct dentry *trans)
{
struct dentry *counters;
int idx;
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);
dbg->top_dentry = top_dentry;
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) = {};
if (!info->dbg)
return -EINVAL;
/* Enumerate all channels to collect their ids */
idr_for_each_entry(&info->tx_idr, cinfo, id) {
/*
* Cannot happen, but be defensive.
* Zero as num_chans is ok, warn and carry on.
*/
if (num_chans >= SCMI_MAX_CHANNELS || !cinfo) {
dev_warn(info->dev,
"SCMI RAW - Error enumerating channels\n");
break;
}
if (!test_bit(cinfo->id, protos)) {
channels[num_chans++] = cinfo->id;
set_bit(cinfo->id, protos);
}
}
info->raw = scmi_raw_mode_init(&info->handle, info->dbg->top_dentry,
info->id, channels, num_chans,
info->desc, info->tx_minfo.max_msg);
if (IS_ERR(info->raw)) {
dev_err(info->dev, "Failed to initialize SCMI RAW Mode !\n");
ret = PTR_ERR(info->raw);
info->raw = NULL;
}
return ret;
}
static 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 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 = 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);
idr_init(&info->rx_idr);
handle = &info->handle;
handle->dev = info->dev;
handle->version = &info->version;
handle->devm_protocol_acquire = scmi_devm_protocol_acquire;
handle->devm_protocol_get = scmi_devm_protocol_get;
handle->devm_protocol_put = scmi_devm_protocol_put;
handle->is_transport_atomic = scmi_is_transport_atomic;
/* 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) {
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 (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
ret = scmi_debugfs_raw_mode_setup(info);
if (!coex) {
if (ret)
goto clear_dev_req_notifier;
/* Bail out anyway when coex disabled. */
return 0;
}
/* Coex enabled, carry on in any case. */
dev_info(dev, "SCMI RAW Mode COEX enabled !\n");
}
}
if (scmi_notification_init(handle))
dev_err(dev, "SCMI Notifications NOT available.\n");
if (info->desc->atomic_enabled &&
!is_transport_polling_capable(info->desc))
dev_err(dev,
"Transport is not polling capable. Atomic mode not supported.\n");
/*
* Trigger SCMI Base protocol initialization.
* It's mandatory and won't be ever released/deinit until the
* SCMI stack is shutdown/unloaded as a whole.
*/
ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE);
if (ret) {
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);
for_each_available_child_of_node(np, child) {
u32 prot_id;
if (of_property_read_u32(child, "reg", &prot_id))
continue;
if (!FIELD_FIT(MSG_PROTOCOL_ID_MASK, prot_id))
dev_err(dev, "Out of range protocol %d\n", prot_id);
if (!scmi_is_protocol_implemented(handle, prot_id)) {
dev_err(dev, "SCMI protocol %d not implemented\n",
prot_id);
continue;
}
/*
* Save this valid DT protocol descriptor amongst
* @active_protocols for this SCMI instance/
*/
ret = idr_alloc(&info->active_protocols, child,
prot_id, prot_id + 1, GFP_KERNEL);
if (ret != prot_id) {
dev_err(dev, "SCMI protocol %d already activated. Skip\n",
prot_id);
continue;
}
of_node_get(child);
scmi_create_protocol_devices(child, info, prot_id, NULL);
}
return 0;
notification_exit:
if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
scmi_raw_mode_cleanup(info->raw);
scmi_notification_exit(&info->handle);
clear_dev_req_notifier:
blocking_notifier_chain_unregister(&scmi_requested_devices_nh,
&info->dev_req_nb);
clear_bus_notifier:
bus_unregister_notifier(&scmi_bus_type, &info->bus_nb);
clear_txrx_setup:
scmi_cleanup_txrx_channels(info);
clear_ida:
ida_free(&scmi_id, info->id);
out_err:
return dev_err_probe(dev, ret, "%s", err_str);
}
static void scmi_remove(struct platform_device *pdev)
{
int id;
struct scmi_info *info = platform_get_drvdata(pdev);
struct device_node *child;
if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT))
scmi_raw_mode_cleanup(info->raw);
mutex_lock(&scmi_list_mutex);
if (info->users)
dev_warn(&pdev->dev,
"Still active SCMI users will be forcibly unbound.\n");
list_del(&info->node);
mutex_unlock(&scmi_list_mutex);
scmi_notification_exit(&info->handle);
mutex_lock(&info->protocols_mtx);
idr_destroy(&info->protocols);
mutex_unlock(&info->protocols_mtx);
idr_for_each_entry(&info->active_protocols, child, id)
of_node_put(child);
idr_destroy(&info->active_protocols);
blocking_notifier_chain_unregister(&scmi_requested_devices_nh,
&info->dev_req_nb);
bus_unregister_notifier(&scmi_bus_type, &info->bus_nb);
/* Safe to free channels since no more users */
scmi_cleanup_txrx_channels(info);
ida_free(&scmi_id, info->id);
}
static ssize_t protocol_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "%u.%u\n", info->version.major_ver,
info->version.minor_ver);
}
static DEVICE_ATTR_RO(protocol_version);
static ssize_t firmware_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "0x%x\n", info->version.impl_ver);
}
static DEVICE_ATTR_RO(firmware_version);
static ssize_t vendor_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "%s\n", info->version.vendor_id);
}
static DEVICE_ATTR_RO(vendor_id);
static ssize_t sub_vendor_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct scmi_info *info = dev_get_drvdata(dev);
return sprintf(buf, "%s\n", info->version.sub_vendor_id);
}
static DEVICE_ATTR_RO(sub_vendor_id);
static struct attribute *versions_attrs[] = {
&dev_attr_firmware_version.attr,
&dev_attr_protocol_version.attr,
&dev_attr_vendor_id.attr,
&dev_attr_sub_vendor_id.attr,
NULL,
};
ATTRIBUTE_GROUPS(versions);
static struct platform_driver scmi_driver = {
.driver = {
.name = "arm-scmi",
.suppress_bind_attrs = true,
.dev_groups = versions_groups,
},
.probe = scmi_probe,
.remove = scmi_remove,
};
static struct dentry *scmi_debugfs_init(void)
{
struct dentry *d;
d = debugfs_create_dir("scmi", NULL);
if (IS_ERR(d)) {
pr_err("Could NOT create SCMI top dentry.\n");
return NULL;
}
return d;
}
static int __init scmi_driver_init(void)
{
/* 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_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("ARM SCMI protocol driver");
MODULE_LICENSE("GPL v2");
Reference in New Issue View Git Blame Copy Permalink