diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/driver.c')
| -rw-r--r-- | drivers/firmware/arm_scmi/driver.c | 798 |
1 files changed, 725 insertions, 73 deletions
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index cacdf1589b10..66eb3f0e5daf 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -11,18 +11,22 @@ * various power domain DVFS including the core/cluster, certain system * clocks configuration, thermal sensors and many others. * - * Copyright (C) 2018 ARM Ltd. + * Copyright (C) 2018-2021 ARM Ltd. */ #include <linux/bitmap.h> +#include <linux/device.h> #include <linux/export.h> +#include <linux/idr.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/ktime.h> +#include <linux/list.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_device.h> #include <linux/processor.h> +#include <linux/refcount.h> #include <linux/slab.h> #include "common.h" @@ -53,6 +57,14 @@ static DEFINE_MUTEX(scmi_list_mutex); /* Track the unique id for the transfers for debug & profiling purpose */ static atomic_t transfer_last_id; +static DEFINE_IDR(scmi_requested_devices); +static DEFINE_MUTEX(scmi_requested_devices_mtx); + +struct scmi_requested_dev { + const struct scmi_device_id *id_table; + struct list_head node; +}; + /** * struct scmi_xfers_info - Structure to manage transfer information * @@ -69,6 +81,30 @@ struct scmi_xfers_info { }; /** + * struct scmi_protocol_instance - Describe an initialized protocol instance. + * @handle: Reference to the SCMI handle associated to this protocol instance. + * @proto: A reference to the protocol descriptor. + * @gid: A reference for per-protocol devres management. + * @users: A refcount to track effective users of this protocol. + * @priv: Reference for optional protocol private data. + * @ph: An embedded protocol handle that will be passed down to protocol + * initialization code to identify this instance. + * + * Each protocol is initialized independently once for each SCMI platform in + * which is defined by DT and implemented by the SCMI server fw. + */ +struct scmi_protocol_instance { + const struct scmi_handle *handle; + const struct scmi_protocol *proto; + void *gid; + refcount_t users; + void *priv; + struct scmi_protocol_handle ph; +}; + +#define ph_to_pi(h) container_of(h, struct scmi_protocol_instance, ph) + +/** * struct scmi_info - Structure representing a SCMI instance * * @dev: Device pointer @@ -80,8 +116,15 @@ struct scmi_xfers_info { * @rx_minfo: Universal Receive Message management info * @tx_idr: IDR object to map protocol id to Tx channel info pointer * @rx_idr: IDR object to map protocol id to Rx channel info pointer + * @protocols: IDR for protocols' instance descriptors initialized for + * this SCMI instance: populated on protocol's first attempted + * usage. + * @protocols_mtx: A mutex to protect protocols instances initialization. * @protocols_imp: List of protocols implemented, currently maximum of * MAX_PROTOCOLS_IMP elements allocated by the base protocol + * @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 */ @@ -94,7 +137,12 @@ struct scmi_info { struct scmi_xfers_info rx_minfo; struct idr tx_idr; struct idr rx_idr; + struct idr protocols; + /* Ensure mutual exclusive access to protocols instance array */ + struct mutex protocols_mtx; u8 *protocols_imp; + struct idr active_protocols; + void *notify_priv; struct list_head node; int users; }; @@ -136,6 +184,25 @@ static inline void scmi_dump_header_dbg(struct device *dev, hdr->id, hdr->seq, hdr->protocol_id); } +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_get() - Allocate one message * @@ -316,14 +383,16 @@ void scmi_rx_callback(struct scmi_chan_info *cinfo, u32 msg_hdr) } /** - * scmi_xfer_put() - Release a transmit message + * xfer_put() - Release a transmit message * - * @handle: Pointer to SCMI entity handle + * @ph: Pointer to SCMI protocol handle * @xfer: message that was reserved by scmi_xfer_get */ -void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer) +static void xfer_put(const struct scmi_protocol_handle *ph, + struct scmi_xfer *xfer) { - struct scmi_info *info = handle_to_scmi_info(handle); + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); __scmi_xfer_put(&info->tx_minfo, xfer); } @@ -340,23 +409,32 @@ static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo, } /** - * scmi_do_xfer() - Do one transfer + * do_xfer() - Do one transfer * - * @handle: Pointer to SCMI entity handle + * @ph: Pointer to SCMI protocol handle * @xfer: Transfer to initiate and wait for response * * Return: -ETIMEDOUT in case of no response, if transmit error, * return corresponding error, else if all goes well, * return 0. */ -int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer) +static int do_xfer(const struct scmi_protocol_handle *ph, + struct scmi_xfer *xfer) { int ret; int timeout; - struct scmi_info *info = handle_to_scmi_info(handle); + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); struct device *dev = info->dev; struct scmi_chan_info *cinfo; + /* + * Re-instate protocol id here from protocol handle so that cannot be + * overridden by mistake (or malice) by the protocol code mangling with + * the scmi_xfer structure. + */ + xfer->hdr.protocol_id = pi->proto->id; + cinfo = idr_find(&info->tx_idr, xfer->hdr.protocol_id); if (unlikely(!cinfo)) return -EINVAL; @@ -402,10 +480,11 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer) return ret; } -void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle, - struct scmi_xfer *xfer) +static void reset_rx_to_maxsz(const struct scmi_protocol_handle *ph, + struct scmi_xfer *xfer) { - struct scmi_info *info = handle_to_scmi_info(handle); + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); xfer->rx.len = info->desc->max_msg_size; } @@ -413,24 +492,27 @@ void scmi_reset_rx_to_maxsz(const struct scmi_handle *handle, #define SCMI_MAX_RESPONSE_TIMEOUT (2 * MSEC_PER_SEC) /** - * scmi_do_xfer_with_response() - Do one transfer and wait until the delayed + * do_xfer_with_response() - Do one transfer and wait until the delayed * response is received * - * @handle: Pointer to SCMI entity handle + * @ph: Pointer to SCMI protocol handle * @xfer: Transfer to initiate and wait for response * * Return: -ETIMEDOUT in case of no delayed response, if transmit error, * return corresponding error, else if all goes well, return 0. */ -int scmi_do_xfer_with_response(const struct scmi_handle *handle, - struct scmi_xfer *xfer) +static int do_xfer_with_response(const struct scmi_protocol_handle *ph, + struct scmi_xfer *xfer) { int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT); + const struct scmi_protocol_instance *pi = ph_to_pi(ph); DECLARE_COMPLETION_ONSTACK(async_response); + xfer->hdr.protocol_id = pi->proto->id; + xfer->async_done = &async_response; - ret = scmi_do_xfer(handle, xfer); + ret = do_xfer(ph, xfer); if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout)) ret = -ETIMEDOUT; @@ -439,11 +521,10 @@ int scmi_do_xfer_with_response(const struct scmi_handle *handle, } /** - * scmi_xfer_get_init() - Allocate and initialise one message for transmit + * xfer_get_init() - Allocate and initialise one message for transmit * - * @handle: Pointer to SCMI entity handle + * @ph: Pointer to SCMI protocol handle * @msg_id: Message identifier - * @prot_id: Protocol identifier for the message * @tx_size: transmit message size * @rx_size: receive message size * @p: pointer to the allocated and initialised message @@ -454,12 +535,14 @@ int scmi_do_xfer_with_response(const struct scmi_handle *handle, * Return: 0 if all went fine with @p pointing to message, else * corresponding error. */ -int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, - size_t tx_size, size_t rx_size, struct scmi_xfer **p) +static int xfer_get_init(const struct scmi_protocol_handle *ph, + u8 msg_id, size_t tx_size, size_t rx_size, + struct scmi_xfer **p) { int ret; struct scmi_xfer *xfer; - struct scmi_info *info = handle_to_scmi_info(handle); + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); struct scmi_xfers_info *minfo = &info->tx_minfo; struct device *dev = info->dev; @@ -468,7 +551,7 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, tx_size > info->desc->max_msg_size) return -ERANGE; - xfer = scmi_xfer_get(handle, minfo); + xfer = scmi_xfer_get(pi->handle, minfo); if (IS_ERR(xfer)) { ret = PTR_ERR(xfer); dev_err(dev, "failed to get free message slot(%d)\n", ret); @@ -478,7 +561,7 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, xfer->tx.len = tx_size; xfer->rx.len = rx_size ? : info->desc->max_msg_size; xfer->hdr.id = msg_id; - xfer->hdr.protocol_id = prot_id; + xfer->hdr.protocol_id = pi->proto->id; xfer->hdr.poll_completion = false; *p = xfer; @@ -487,43 +570,276 @@ int scmi_xfer_get_init(const struct scmi_handle *handle, u8 msg_id, u8 prot_id, } /** - * scmi_version_get() - command to get the revision of the SCMI entity + * version_get() - command to get the revision of the SCMI entity * - * @handle: Pointer to SCMI entity handle - * @protocol: Protocol identifier for the message + * @ph: Pointer to SCMI protocol handle * @version: Holds returned version of protocol. * * Updates the SCMI information in the internal data structure. * * Return: 0 if all went fine, else return appropriate error. */ -int scmi_version_get(const struct scmi_handle *handle, u8 protocol, - u32 *version) +static int version_get(const struct scmi_protocol_handle *ph, u32 *version) { int ret; __le32 *rev_info; struct scmi_xfer *t; - ret = scmi_xfer_get_init(handle, PROTOCOL_VERSION, protocol, 0, - sizeof(*version), &t); + ret = xfer_get_init(ph, PROTOCOL_VERSION, 0, sizeof(*version), &t); if (ret) return ret; - ret = scmi_do_xfer(handle, t); + ret = do_xfer(ph, t); if (!ret) { rev_info = t->rx.buf; *version = le32_to_cpu(*rev_info); } - scmi_xfer_put(handle, t); + xfer_put(ph, t); return ret; } -void scmi_setup_protocol_implemented(const struct scmi_handle *handle, - u8 *prot_imp) +/** + * scmi_set_protocol_priv - Set protocol specific data at init time + * + * @ph: A reference to the protocol handle. + * @priv: The private data to set. + * + * Return: 0 on Success + */ +static int scmi_set_protocol_priv(const struct scmi_protocol_handle *ph, + void *priv) { + struct scmi_protocol_instance *pi = ph_to_pi(ph); + + pi->priv = priv; + + return 0; +} + +/** + * scmi_get_protocol_priv - Set protocol specific data at init time + * + * @ph: A reference to the protocol handle. + * + * Return: Protocol private data if any was set. + */ +static void *scmi_get_protocol_priv(const struct scmi_protocol_handle *ph) +{ + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + + return pi->priv; +} + +static const struct scmi_xfer_ops xfer_ops = { + .version_get = version_get, + .xfer_get_init = xfer_get_init, + .reset_rx_to_maxsz = reset_rx_to_maxsz, + .do_xfer = do_xfer, + .do_xfer_with_response = do_xfer_with_response, + .xfer_put = xfer_put, +}; + +/** + * scmi_revision_area_get - Retrieve version memory area. + * + * @ph: A reference to the protocol handle. + * + * A helper to grab the version memory area reference during SCMI Base protocol + * initialization. + * + * Return: A reference to the version memory area associated to the SCMI + * instance underlying this protocol handle. + */ +struct scmi_revision_info * +scmi_revision_area_get(const struct scmi_protocol_handle *ph) +{ + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + + return pi->handle->version; +} + +/** + * scmi_alloc_init_protocol_instance - Allocate and initialize a protocol + * instance descriptor. + * @info: The reference to the related SCMI instance. + * @proto: The protocol descriptor. + * + * Allocate a new protocol instance descriptor, using the provided @proto + * description, against the specified SCMI instance @info, and initialize it; + * all resources management is handled via a dedicated per-protocol devres + * group. + * + * Context: Assumes to be called with @protocols_mtx already acquired. + * Return: A reference to a freshly allocated and initialized protocol instance + * or ERR_PTR on failure. On failure the @proto reference is at first + * put using @scmi_protocol_put() before releasing all the devres group. + */ +static struct scmi_protocol_instance * +scmi_alloc_init_protocol_instance(struct scmi_info *info, + const struct scmi_protocol *proto) +{ + int ret = -ENOMEM; + void *gid; + struct scmi_protocol_instance *pi; + const struct scmi_handle *handle = &info->handle; + + /* Protocol specific devres group */ + gid = devres_open_group(handle->dev, NULL, GFP_KERNEL); + if (!gid) { + scmi_protocol_put(proto->id); + goto out; + } + + pi = devm_kzalloc(handle->dev, sizeof(*pi), GFP_KERNEL); + if (!pi) + goto clean; + + pi->gid = gid; + pi->proto = proto; + pi->handle = handle; + pi->ph.dev = handle->dev; + pi->ph.xops = &xfer_ops; + pi->ph.set_priv = scmi_set_protocol_priv; + pi->ph.get_priv = scmi_get_protocol_priv; + refcount_set(&pi->users, 1); + /* proto->init is assured NON NULL by scmi_protocol_register */ + ret = pi->proto->instance_init(&pi->ph); + if (ret) + goto clean; + + ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1, + GFP_KERNEL); + if (ret != proto->id) + goto clean; + + /* + * Warn but ignore events registration errors since we do not want + * to skip whole protocols if their notifications are messed up. + */ + if (pi->proto->events) { + ret = scmi_register_protocol_events(handle, pi->proto->id, + &pi->ph, + pi->proto->events); + if (ret) + dev_warn(handle->dev, + "Protocol:%X - Events Registration Failed - err:%d\n", + pi->proto->id, ret); + } + + devres_close_group(handle->dev, pi->gid); + dev_dbg(handle->dev, "Initialized protocol: 0x%X\n", pi->proto->id); + + return pi; + +clean: + /* Take care to put the protocol module's owner before releasing all */ + scmi_protocol_put(proto->id); + devres_release_group(handle->dev, gid); +out: + return ERR_PTR(ret); +} + +/** + * scmi_get_protocol_instance - Protocol initialization helper. + * @handle: A reference to the SCMI platform instance. + * @protocol_id: The protocol being requested. + * + * In case the required protocol has never been requested before for this + * instance, allocate and initialize all the needed structures while handling + * resource allocation with a dedicated per-protocol devres subgroup. + * + * Return: A reference to an initialized protocol instance or error on failure: + * in particular returns -EPROBE_DEFER when the desired protocol could + * NOT be found. + */ +static struct scmi_protocol_instance * __must_check +scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id) +{ + struct scmi_protocol_instance *pi; struct scmi_info *info = handle_to_scmi_info(handle); + mutex_lock(&info->protocols_mtx); + pi = idr_find(&info->protocols, protocol_id); + + if (pi) { + refcount_inc(&pi->users); + } else { + const struct scmi_protocol *proto; + + /* Fails if protocol not registered on bus */ + proto = scmi_protocol_get(protocol_id); + if (proto) + pi = scmi_alloc_init_protocol_instance(info, proto); + else + pi = ERR_PTR(-EPROBE_DEFER); + } + mutex_unlock(&info->protocols_mtx); + + return pi; +} + +/** + * scmi_protocol_acquire - Protocol acquire + * @handle: A reference to the SCMI platform instance. + * @protocol_id: The protocol being requested. + * + * Register a new user for the requested protocol on the specified SCMI + * platform instance, possibly triggering its initialization on first user. + * + * Return: 0 if protocol was acquired successfully. + */ +int scmi_protocol_acquire(const struct scmi_handle *handle, u8 protocol_id) +{ + return PTR_ERR_OR_ZERO(scmi_get_protocol_instance(handle, protocol_id)); +} + +/** + * scmi_protocol_release - Protocol de-initialization helper. + * @handle: A reference to the SCMI platform instance. + * @protocol_id: The protocol being requested. + * + * Remove one user for the specified protocol and triggers de-initialization + * and resources de-allocation once the last user has gone. + */ +void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) +{ + struct scmi_info *info = handle_to_scmi_info(handle); + struct scmi_protocol_instance *pi; + + mutex_lock(&info->protocols_mtx); + pi = idr_find(&info->protocols, protocol_id); + if (WARN_ON(!pi)) + goto out; + + if (refcount_dec_and_test(&pi->users)) { + void *gid = pi->gid; + + if (pi->proto->events) + scmi_deregister_protocol_events(handle, protocol_id); + + if (pi->proto->instance_deinit) + pi->proto->instance_deinit(&pi->ph); + + idr_remove(&info->protocols, protocol_id); + + scmi_protocol_put(protocol_id); + + devres_release_group(handle->dev, gid); + dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n", + protocol_id); + } + +out: + mutex_unlock(&info->protocols_mtx); +} + +void scmi_setup_protocol_implemented(const struct scmi_protocol_handle *ph, + u8 *prot_imp) +{ + const struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); + info->protocols_imp = prot_imp; } @@ -542,6 +858,102 @@ scmi_is_protocol_implemented(const struct scmi_handle *handle, u8 prot_id) return false; } +struct scmi_protocol_devres { + const struct scmi_handle *handle; + u8 protocol_id; +}; + +static void scmi_devm_release_protocol(struct device *dev, void *res) +{ + struct scmi_protocol_devres *dres = res; + + scmi_protocol_release(dres->handle, dres->protocol_id); +} + +/** + * scmi_devm_protocol_get - Devres managed get protocol operations and handle + * @sdev: A reference to an scmi_device whose embedded struct device is to + * be used for devres accounting. + * @protocol_id: The protocol being requested. + * @ph: A pointer reference used to pass back the associated protocol handle. + * + * Get hold of a protocol accounting for its usage, eventually triggering its + * initialization, and returning the protocol specific operations and related + * protocol handle which will be used as first argument in most of the + * protocols operations methods. + * Being a devres based managed method, protocol hold will be automatically + * released, and possibly de-initialized on last user, once the SCMI driver + * owning the scmi_device is unbound from it. + * + * Return: A reference to the requested protocol operations or error. + * Must be checked for errors by caller. + */ +static const void __must_check * +scmi_devm_protocol_get(struct scmi_device *sdev, u8 protocol_id, + struct scmi_protocol_handle **ph) +{ + struct scmi_protocol_instance *pi; + struct scmi_protocol_devres *dres; + struct scmi_handle *handle = sdev->handle; + + if (!ph) + return ERR_PTR(-EINVAL); + + dres = devres_alloc(scmi_devm_release_protocol, + sizeof(*dres), GFP_KERNEL); + if (!dres) + return ERR_PTR(-ENOMEM); + + pi = scmi_get_protocol_instance(handle, protocol_id); + if (IS_ERR(pi)) { + devres_free(dres); + return pi; + } + + dres->handle = handle; + dres->protocol_id = protocol_id; + devres_add(&sdev->dev, dres); + + *ph = &pi->ph; + + return pi->proto->ops; +} + +static int scmi_devm_protocol_match(struct device *dev, void *res, void *data) +{ + struct scmi_protocol_devres *dres = res; + + if (WARN_ON(!dres || !data)) + return 0; + + return dres->protocol_id == *((u8 *)data); +} + +/** + * scmi_devm_protocol_put - Devres managed put protocol operations and handle + * @sdev: A reference to an scmi_device whose embedded struct device is to + * be used for devres accounting. + * @protocol_id: The protocol being requested. + * + * Explicitly release a protocol hold previously obtained calling the above + * @scmi_devm_protocol_get. + */ +static void scmi_devm_protocol_put(struct scmi_device *sdev, u8 protocol_id) +{ + int ret; + + ret = devres_release(&sdev->dev, scmi_devm_release_protocol, + scmi_devm_protocol_match, &protocol_id); + WARN_ON(ret); +} + +static inline +struct scmi_handle *scmi_handle_get_from_info_unlocked(struct scmi_info *info) +{ + info->users++; + return &info->handle; +} + /** * scmi_handle_get() - Get the SCMI handle for a device * @@ -563,8 +975,7 @@ struct scmi_handle *scmi_handle_get(struct device *dev) list_for_each(p, &scmi_list) { info = list_entry(p, struct scmi_info, node); if (dev->parent == info->dev) { - handle = &info->handle; - info->users++; + handle = scmi_handle_get_from_info_unlocked(info); break; } } @@ -707,63 +1118,268 @@ scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id) return ret; } -static inline void -scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, - int prot_id, const char *name) +/** + * scmi_get_protocol_device - Helper to get/create an SCMI device. + * + * @np: A device node representing a valid active protocols for the referred + * SCMI instance. + * @info: The referred SCMI instance for which we are getting/creating this + * device. + * @prot_id: The protocol ID. + * @name: The device name. + * + * Referring to the specific SCMI instance identified by @info, this helper + * takes care to return a properly initialized device matching the requested + * @proto_id and @name: if device was still not existent it is created as a + * child of the specified SCMI instance @info and its transport properly + * initialized as usual. + */ +static inline struct scmi_device * +scmi_get_protocol_device(struct device_node *np, struct scmi_info *info, + int prot_id, const char *name) { struct scmi_device *sdev; + /* Already created for this parent SCMI instance ? */ + sdev = scmi_child_dev_find(info->dev, prot_id, name); + if (sdev) + return sdev; + + pr_debug("Creating SCMI device (%s) for protocol %x\n", name, prot_id); + sdev = scmi_device_create(np, info->dev, prot_id, name); if (!sdev) { dev_err(info->dev, "failed to create %d protocol device\n", prot_id); - return; + return NULL; } if (scmi_txrx_setup(info, &sdev->dev, prot_id)) { dev_err(&sdev->dev, "failed to setup transport\n"); scmi_device_destroy(sdev); - return; + return NULL; } + return sdev; +} + +static inline void +scmi_create_protocol_device(struct device_node *np, struct scmi_info *info, + int prot_id, const char *name) +{ + struct scmi_device *sdev; + + sdev = scmi_get_protocol_device(np, info, prot_id, name); + if (!sdev) + return; + /* setup handle now as the transport is ready */ scmi_set_handle(sdev); } -#define MAX_SCMI_DEV_PER_PROTOCOL 2 -struct scmi_prot_devnames { - int protocol_id; - char *names[MAX_SCMI_DEV_PER_PROTOCOL]; -}; +/** + * scmi_create_protocol_devices - Create devices for all pending requests for + * this SCMI instance. + * + * @np: The device node describing the protocol + * @info: The SCMI instance descriptor + * @prot_id: The protocol ID + * + * All devices previously requested for this instance (if any) are found and + * created by scanning the proper @&scmi_requested_devices entry. + */ +static void scmi_create_protocol_devices(struct device_node *np, + struct scmi_info *info, int prot_id) +{ + struct list_head *phead; -static struct scmi_prot_devnames devnames[] = { - { SCMI_PROTOCOL_POWER, { "genpd" },}, - { SCMI_PROTOCOL_SYSTEM, { "syspower" },}, - { SCMI_PROTOCOL_PERF, { "cpufreq" },}, - { SCMI_PROTOCOL_CLOCK, { "clocks" },}, - { SCMI_PROTOCOL_SENSOR, { "hwmon" },}, - { SCMI_PROTOCOL_RESET, { "reset" },}, - { SCMI_PROTOCOL_VOLTAGE, { "regulator" },}, -}; + mutex_lock(&scmi_requested_devices_mtx); + phead = idr_find(&scmi_requested_devices, prot_id); + if (phead) { + struct scmi_requested_dev *rdev; -static inline void -scmi_create_protocol_devices(struct device_node *np, struct scmi_info *info, - int prot_id) + list_for_each_entry(rdev, phead, node) + scmi_create_protocol_device(np, info, prot_id, + rdev->id_table->name); + } + mutex_unlock(&scmi_requested_devices_mtx); +} + +/** + * scmi_protocol_device_request - Helper to request a device + * + * @id_table: A protocol/name pair descriptor for the device to be created. + * + * This helper let an SCMI driver request specific devices identified by the + * @id_table to be created for each active SCMI instance. + * + * The requested device name MUST NOT be already existent for any protocol; + * at first the freshly requested @id_table is annotated in the IDR table + * @scmi_requested_devices, then a matching device is created for each already + * active SCMI instance. (if any) + * + * This way the requested device is created straight-away for all the already + * initialized(probed) SCMI instances (handles) and it remains also annotated + * as pending creation if the requesting SCMI driver was loaded before some + * SCMI instance and related transports were available: when such late instance + * is probed, its probe will take care to scan the list of pending requested + * devices and create those on its own (see @scmi_create_protocol_devices and + * its enclosing loop) + * + * Return: 0 on Success + */ +int scmi_protocol_device_request(const struct scmi_device_id *id_table) { - int loop, cnt; + int ret = 0; + unsigned int id = 0; + struct list_head *head, *phead = NULL; + struct scmi_requested_dev *rdev; + struct scmi_info *info; - for (loop = 0; loop < ARRAY_SIZE(devnames); loop++) { - if (devnames[loop].protocol_id != prot_id) - continue; + pr_debug("Requesting SCMI device (%s) for protocol %x\n", + id_table->name, id_table->protocol_id); - for (cnt = 0; cnt < ARRAY_SIZE(devnames[loop].names); cnt++) { - const char *name = devnames[loop].names[cnt]; + /* + * Search for the matching protocol rdev list and then search + * of any existent equally named device...fails if any duplicate found. + */ + mutex_lock(&scmi_requested_devices_mtx); + idr_for_each_entry(&scmi_requested_devices, head, id) { + if (!phead) { + /* A list found registered in the IDR is never empty */ + rdev = list_first_entry(head, struct scmi_requested_dev, + node); + if (rdev->id_table->protocol_id == + id_table->protocol_id) + phead = head; + } + list_for_each_entry(rdev, head, node) { + if (!strcmp(rdev->id_table->name, id_table->name)) { + pr_err("Ignoring duplicate request [%d] %s\n", + rdev->id_table->protocol_id, + rdev->id_table->name); + ret = -EINVAL; + goto out; + } + } + } + + /* + * No duplicate found for requested id_table, so let's create a new + * requested device entry for this new valid request. + */ + rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); + if (!rdev) { + ret = -ENOMEM; + goto out; + } + rdev->id_table = id_table; - if (name) - scmi_create_protocol_device(np, info, prot_id, - name); + /* + * Append the new requested device table descriptor to the head of the + * related protocol list, eventually creating such head if not already + * there. + */ + if (!phead) { + phead = kzalloc(sizeof(*phead), GFP_KERNEL); + if (!phead) { + kfree(rdev); + ret = -ENOMEM; + goto out; + } + INIT_LIST_HEAD(phead); + + ret = idr_alloc(&scmi_requested_devices, (void *)phead, + id_table->protocol_id, + id_table->protocol_id + 1, GFP_KERNEL); + if (ret != id_table->protocol_id) { + pr_err("Failed to save SCMI device - ret:%d\n", ret); + kfree(rdev); + kfree(phead); + ret = -EINVAL; + goto out; } + ret = 0; } + list_add(&rdev->node, phead); + + /* + * Now effectively create and initialize the requested device for every + * already initialized SCMI instance which has registered the requested + * protocol as a valid active one: i.e. defined in DT and supported by + * current platform FW. + */ + mutex_lock(&scmi_list_mutex); + list_for_each_entry(info, &scmi_list, node) { + struct device_node *child; + + child = idr_find(&info->active_protocols, + id_table->protocol_id); + if (child) { + struct scmi_device *sdev; + + sdev = scmi_get_protocol_device(child, info, + id_table->protocol_id, + id_table->name); + /* Set handle if not already set: device existed */ + if (sdev && !sdev->handle) + sdev->handle = + scmi_handle_get_from_info_unlocked(info); + } else { + dev_err(info->dev, + "Failed. SCMI protocol %d not active.\n", + id_table->protocol_id); + } + } + mutex_unlock(&scmi_list_mutex); + +out: + mutex_unlock(&scmi_requested_devices_mtx); + + return ret; +} + +/** + * scmi_protocol_device_unrequest - Helper to unrequest a device + * + * @id_table: A protocol/name pair descriptor for the device to be unrequested. + * + * An helper to let an SCMI driver release its request about devices; note that + * devices are created and initialized once the first SCMI driver request them + * but they destroyed only on SCMI core unloading/unbinding. + * + * The current SCMI transport layer uses such devices as internal references and + * as such they could be shared as same transport between multiple drivers so + * that cannot be safely destroyed till the whole SCMI stack is removed. + * (unless adding further burden of refcounting.) + */ +void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table) +{ + struct list_head *phead; + + pr_debug("Unrequesting SCMI device (%s) for protocol %x\n", + id_table->name, id_table->protocol_id); + + mutex_lock(&scmi_requested_devices_mtx); + phead = idr_find(&scmi_requested_devices, id_table->protocol_id); + if (phead) { + struct scmi_requested_dev *victim, *tmp; + + list_for_each_entry_safe(victim, tmp, phead, node) { + if (!strcmp(victim->id_table->name, id_table->name)) { + list_del(&victim->node); + kfree(victim); + break; + } + } + + if (list_empty(phead)) { + idr_remove(&scmi_requested_devices, + id_table->protocol_id); + kfree(phead); + } + } + mutex_unlock(&scmi_requested_devices_mtx); } static int scmi_probe(struct platform_device *pdev) @@ -786,6 +1402,9 @@ static int scmi_probe(struct platform_device *pdev) info->dev = dev; info->desc = desc; INIT_LIST_HEAD(&info->node); + idr_init(&info->protocols); + mutex_init(&info->protocols_mtx); + idr_init(&info->active_protocols); platform_set_drvdata(pdev, info); idr_init(&info->tx_idr); @@ -794,6 +1413,8 @@ static int scmi_probe(struct platform_device *pdev) handle = &info->handle; handle->dev = info->dev; handle->version = &info->version; + handle->devm_protocol_get = scmi_devm_protocol_get; + handle->devm_protocol_put = scmi_devm_protocol_put; ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE); if (ret) @@ -806,9 +1427,14 @@ static int scmi_probe(struct platform_device *pdev) if (scmi_notification_init(handle)) dev_err(dev, "SCMI Notifications NOT available.\n"); - ret = scmi_base_protocol_init(handle); + /* + * Trigger SCMI Base protocol initialization. + * It's mandatory and won't be ever released/deinit until the + * SCMI stack is shutdown/unloaded as a whole. + */ + ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE); if (ret) { - dev_err(dev, "unable to communicate with SCMI(%d)\n", ret); + dev_err(dev, "unable to communicate with SCMI\n"); return ret; } @@ -831,6 +1457,19 @@ static int scmi_probe(struct platform_device *pdev) 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); } @@ -844,9 +1483,10 @@ void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) static int scmi_remove(struct platform_device *pdev) { - int ret = 0; + int ret = 0, id; struct scmi_info *info = platform_get_drvdata(pdev); struct idr *idr = &info->tx_idr; + struct device_node *child; mutex_lock(&scmi_list_mutex); if (info->users) @@ -860,6 +1500,14 @@ static int scmi_remove(struct platform_device *pdev) scmi_notification_exit(&info->handle); + mutex_lock(&info->protocols_mtx); + idr_destroy(&info->protocols); + mutex_unlock(&info->protocols_mtx); + + idr_for_each_entry(&info->active_protocols, child, id) + of_node_put(child); + idr_destroy(&info->active_protocols); + /* Safe to free channels since no more users */ ret = idr_for_each(idr, info->desc->ops->chan_free, idr); idr_destroy(&info->tx_idr); @@ -942,6 +1590,8 @@ static int __init scmi_driver_init(void) { scmi_bus_init(); + scmi_base_register(); + scmi_clock_register(); scmi_perf_register(); scmi_power_register(); @@ -956,7 +1606,7 @@ subsys_initcall(scmi_driver_init); static void __exit scmi_driver_exit(void) { - scmi_bus_exit(); + scmi_base_unregister(); scmi_clock_unregister(); scmi_perf_unregister(); @@ -966,6 +1616,8 @@ static void __exit scmi_driver_exit(void) scmi_voltage_unregister(); scmi_system_unregister(); + scmi_bus_exit(); + platform_driver_unregister(&scmi_driver); } module_exit(scmi_driver_exit); |