diff --git a/Documentation/interconnect/interconnect.rst b/Documentation/interconnect/interconnect.rst new file mode 100644 index 0000000000000000000000000000000000000000..b8107dcc4cd351c6ac98d75fc71b599a2f09d025 --- /dev/null +++ b/Documentation/interconnect/interconnect.rst @@ -0,0 +1,94 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================================== +GENERIC SYSTEM INTERCONNECT SUBSYSTEM +===================================== + +Introduction +------------ + +This framework is designed to provide a standard kernel interface to control +the settings of the interconnects on an SoC. These settings can be throughput, +latency and priority between multiple interconnected devices or functional +blocks. This can be controlled dynamically in order to save power or provide +maximum performance. + +The interconnect bus is hardware with configurable parameters, which can be +set on a data path according to the requests received from various drivers. +An example of interconnect buses are the interconnects between various +components or functional blocks in chipsets. There can be multiple interconnects +on an SoC that can be multi-tiered. + +Below is a simplified diagram of a real-world SoC interconnect bus topology. + +:: + + +----------------+ +----------------+ + | HW Accelerator |--->| M NoC |<---------------+ + +----------------+ +----------------+ | + | | +------------+ + +-----+ +-------------+ V +------+ | | + | DDR | | +--------+ | PCIe | | | + +-----+ | | Slaves | +------+ | | + ^ ^ | +--------+ | | C NoC | + | | V V | | + +------------------+ +------------------------+ | | +-----+ + | |-->| |-->| |-->| CPU | + | |-->| |<--| | +-----+ + | Mem NoC | | S NoC | +------------+ + | |<--| |---------+ | + | |<--| |<------+ | | +--------+ + +------------------+ +------------------------+ | | +-->| Slaves | + ^ ^ ^ ^ ^ | | +--------+ + | | | | | | V + +------+ | +-----+ +-----+ +---------+ +----------------+ +--------+ + | CPUs | | | GPU | | DSP | | Masters |-->| P NoC |-->| Slaves | + +------+ | +-----+ +-----+ +---------+ +----------------+ +--------+ + | + +-------+ + | Modem | + +-------+ + +Terminology +----------- + +Interconnect provider is the software definition of the interconnect hardware. +The interconnect providers on the above diagram are M NoC, S NoC, C NoC, P NoC +and Mem NoC. + +Interconnect node is the software definition of the interconnect hardware +port. Each interconnect provider consists of multiple interconnect nodes, +which are connected to other SoC components including other interconnect +providers. The point on the diagram where the CPUs connect to the memory is +called an interconnect node, which belongs to the Mem NoC interconnect provider. + +Interconnect endpoints are the first or the last element of the path. Every +endpoint is a node, but not every node is an endpoint. + +Interconnect path is everything between two endpoints including all the nodes +that have to be traversed to reach from a source to destination node. It may +include multiple master-slave pairs across several interconnect providers. + +Interconnect consumers are the entities which make use of the data paths exposed +by the providers. The consumers send requests to providers requesting various +throughput, latency and priority. Usually the consumers are device drivers, that +send request based on their needs. An example for a consumer is a video decoder +that supports various formats and image sizes. + +Interconnect providers +---------------------- + +Interconnect provider is an entity that implements methods to initialize and +configure interconnect bus hardware. The interconnect provider drivers should +be registered with the interconnect provider core. + +.. kernel-doc:: include/linux/interconnect-provider.h + +Interconnect consumers +---------------------- + +Interconnect consumers are the clients which use the interconnect APIs to +get paths between endpoints and set their bandwidth/latency/QoS requirements +for these interconnect paths. + +.. kernel-doc:: include/linux/interconnect.h diff --git a/drivers/Kconfig b/drivers/Kconfig index 4f9f99057ff85f9f14ae856cf70616f74d9c78ab..45f9decb9848c182f3d5e1978cab2abc9009b73a 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -228,4 +228,6 @@ source "drivers/siox/Kconfig" source "drivers/slimbus/Kconfig" +source "drivers/interconnect/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index e1ce029d28fdba01b73752d311d072ec6b81fab5..bb15b9d0e79399fa32a025fd7ff1124cd2041443 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -186,3 +186,4 @@ obj-$(CONFIG_MULTIPLEXER) += mux/ obj-$(CONFIG_UNISYS_VISORBUS) += visorbus/ obj-$(CONFIG_SIOX) += siox/ obj-$(CONFIG_GNSS) += gnss/ +obj-$(CONFIG_INTERCONNECT) += interconnect/ diff --git a/drivers/interconnect/Kconfig b/drivers/interconnect/Kconfig new file mode 100644 index 0000000000000000000000000000000000000000..a261c7d41deb85cf3144a89a21b8c9d32833c8e5 --- /dev/null +++ b/drivers/interconnect/Kconfig @@ -0,0 +1,10 @@ +menuconfig INTERCONNECT + tristate "On-Chip Interconnect management support" + help + Support for management of the on-chip interconnects. + + This framework is designed to provide a generic interface for + managing the interconnects in a SoC. + + If unsure, say no. + diff --git a/drivers/interconnect/Makefile b/drivers/interconnect/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..7a01f33b5593498db2708e56d796877f731e3e0c --- /dev/null +++ b/drivers/interconnect/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 + +icc-core-objs := core.o + +obj-$(CONFIG_INTERCONNECT) += icc-core.o diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c new file mode 100644 index 0000000000000000000000000000000000000000..2b937b4f43c47d89fdfdd3284a93490319eb6554 --- /dev/null +++ b/drivers/interconnect/core.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Interconnect framework core driver + * + * Copyright (c) 2017-2019, Linaro Ltd. + * Author: Georgi Djakov + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_IDR(icc_idr); +static LIST_HEAD(icc_providers); +static DEFINE_MUTEX(icc_lock); + +/** + * struct icc_req - constraints that are attached to each node + * @req_node: entry in list of requests for the particular @node + * @node: the interconnect node to which this constraint applies + * @dev: reference to the device that sets the constraints + * @avg_bw: an integer describing the average bandwidth in kBps + * @peak_bw: an integer describing the peak bandwidth in kBps + */ +struct icc_req { + struct hlist_node req_node; + struct icc_node *node; + struct device *dev; + u32 avg_bw; + u32 peak_bw; +}; + +/** + * struct icc_path - interconnect path structure + * @num_nodes: number of hops (nodes) + * @reqs: array of the requests applicable to this path of nodes + */ +struct icc_path { + size_t num_nodes; + struct icc_req reqs[]; +}; + +static struct icc_node *node_find(const int id) +{ + return idr_find(&icc_idr, id); +} + +static struct icc_path *path_init(struct device *dev, struct icc_node *dst, + ssize_t num_nodes) +{ + struct icc_node *node = dst; + struct icc_path *path; + int i; + + path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL); + if (!path) + return ERR_PTR(-ENOMEM); + + path->num_nodes = num_nodes; + + for (i = num_nodes - 1; i >= 0; i--) { + node->provider->users++; + hlist_add_head(&path->reqs[i].req_node, &node->req_list); + path->reqs[i].node = node; + path->reqs[i].dev = dev; + /* reference to previous node was saved during path traversal */ + node = node->reverse; + } + + return path; +} + +static struct icc_path *path_find(struct device *dev, struct icc_node *src, + struct icc_node *dst) +{ + struct icc_path *path = ERR_PTR(-EPROBE_DEFER); + struct icc_node *n, *node = NULL; + struct list_head traverse_list; + struct list_head edge_list; + struct list_head visited_list; + size_t i, depth = 1; + bool found = false; + + INIT_LIST_HEAD(&traverse_list); + INIT_LIST_HEAD(&edge_list); + INIT_LIST_HEAD(&visited_list); + + list_add(&src->search_list, &traverse_list); + src->reverse = NULL; + + do { + list_for_each_entry_safe(node, n, &traverse_list, search_list) { + if (node == dst) { + found = true; + list_splice_init(&edge_list, &visited_list); + list_splice_init(&traverse_list, &visited_list); + break; + } + for (i = 0; i < node->num_links; i++) { + struct icc_node *tmp = node->links[i]; + + if (!tmp) { + path = ERR_PTR(-ENOENT); + goto out; + } + + if (tmp->is_traversed) + continue; + + tmp->is_traversed = true; + tmp->reverse = node; + list_add_tail(&tmp->search_list, &edge_list); + } + } + + if (found) + break; + + list_splice_init(&traverse_list, &visited_list); + list_splice_init(&edge_list, &traverse_list); + + /* count the hops including the source */ + depth++; + + } while (!list_empty(&traverse_list)); + +out: + + /* reset the traversed state */ + list_for_each_entry_reverse(n, &visited_list, search_list) + n->is_traversed = false; + + if (found) + path = path_init(dev, dst, depth); + + return path; +} + +/* + * We want the path to honor all bandwidth requests, so the average and peak + * bandwidth requirements from each consumer are aggregated at each node. + * The aggregation is platform specific, so each platform can customize it by + * implementing its own aggregate() function. + */ + +static int aggregate_requests(struct icc_node *node) +{ + struct icc_provider *p = node->provider; + struct icc_req *r; + + node->avg_bw = 0; + node->peak_bw = 0; + + hlist_for_each_entry(r, &node->req_list, req_node) + p->aggregate(node, r->avg_bw, r->peak_bw, + &node->avg_bw, &node->peak_bw); + + return 0; +} + +static int apply_constraints(struct icc_path *path) +{ + struct icc_node *next, *prev = NULL; + int ret = -EINVAL; + int i; + + for (i = 0; i < path->num_nodes; i++) { + next = path->reqs[i].node; + + /* + * Both endpoints should be valid master-slave pairs of the + * same interconnect provider that will be configured. + */ + if (!prev || next->provider != prev->provider) { + prev = next; + continue; + } + + /* set the constraints */ + ret = next->provider->set(prev, next); + if (ret) + goto out; + + prev = next; + } +out: + return ret; +} + +/** + * icc_set_bw() - set bandwidth constraints on an interconnect path + * @path: reference to the path returned by icc_get() + * @avg_bw: average bandwidth in kilobytes per second + * @peak_bw: peak bandwidth in kilobytes per second + * + * This function is used by an interconnect consumer to express its own needs + * in terms of bandwidth for a previously requested path between two endpoints. + * The requests are aggregated and each node is updated accordingly. The entire + * path is locked by a mutex to ensure that the set() is completed. + * The @path can be NULL when the "interconnects" DT properties is missing, + * which will mean that no constraints will be set. + * + * Returns 0 on success, or an appropriate error code otherwise. + */ +int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) +{ + struct icc_node *node; + size_t i; + int ret; + + if (!path) + return 0; + + mutex_lock(&icc_lock); + + for (i = 0; i < path->num_nodes; i++) { + node = path->reqs[i].node; + + /* update the consumer request for this path */ + path->reqs[i].avg_bw = avg_bw; + path->reqs[i].peak_bw = peak_bw; + + /* aggregate requests for this node */ + aggregate_requests(node); + } + + ret = apply_constraints(path); + if (ret) + pr_debug("interconnect: error applying constraints (%d)\n", + ret); + + mutex_unlock(&icc_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(icc_set_bw); + +/** + * icc_get() - return a handle for path between two endpoints + * @dev: the device requesting the path + * @src_id: source device port id + * @dst_id: destination device port id + * + * This function will search for a path between two endpoints and return an + * icc_path handle on success. Use icc_put() to release + * constraints when they are not needed anymore. + * If the interconnect API is disabled, NULL is returned and the consumer + * drivers will still build. Drivers are free to handle this specifically, + * but they don't have to. + * + * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the + * interconnect API is disabled. + */ +struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id) +{ + struct icc_node *src, *dst; + struct icc_path *path = ERR_PTR(-EPROBE_DEFER); + + mutex_lock(&icc_lock); + + src = node_find(src_id); + if (!src) + goto out; + + dst = node_find(dst_id); + if (!dst) + goto out; + + path = path_find(dev, src, dst); + if (IS_ERR(path)) + dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); + +out: + mutex_unlock(&icc_lock); + return path; +} +EXPORT_SYMBOL_GPL(icc_get); + +/** + * icc_put() - release the reference to the icc_path + * @path: interconnect path + * + * Use this function to release the constraints on a path when the path is + * no longer needed. The constraints will be re-aggregated. + */ +void icc_put(struct icc_path *path) +{ + struct icc_node *node; + size_t i; + int ret; + + if (!path || WARN_ON(IS_ERR(path))) + return; + + ret = icc_set_bw(path, 0, 0); + if (ret) + pr_err("%s: error (%d)\n", __func__, ret); + + mutex_lock(&icc_lock); + for (i = 0; i < path->num_nodes; i++) { + node = path->reqs[i].node; + hlist_del(&path->reqs[i].req_node); + if (!WARN_ON(!node->provider->users)) + node->provider->users--; + } + mutex_unlock(&icc_lock); + + kfree(path); +} +EXPORT_SYMBOL_GPL(icc_put); + +static struct icc_node *icc_node_create_nolock(int id) +{ + struct icc_node *node; + + /* check if node already exists */ + node = node_find(id); + if (node) + return node; + + node = kzalloc(sizeof(*node), GFP_KERNEL); + if (!node) + return ERR_PTR(-ENOMEM); + + id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL); + if (id < 0) { + WARN(1, "%s: couldn't get idr\n", __func__); + kfree(node); + return ERR_PTR(id); + } + + node->id = id; + + return node; +} + +/** + * icc_node_create() - create a node + * @id: node id + * + * Return: icc_node pointer on success, or ERR_PTR() on error + */ +struct icc_node *icc_node_create(int id) +{ + struct icc_node *node; + + mutex_lock(&icc_lock); + + node = icc_node_create_nolock(id); + + mutex_unlock(&icc_lock); + + return node; +} +EXPORT_SYMBOL_GPL(icc_node_create); + +/** + * icc_node_destroy() - destroy a node + * @id: node id + */ +void icc_node_destroy(int id) +{ + struct icc_node *node; + + mutex_lock(&icc_lock); + + node = node_find(id); + if (node) { + idr_remove(&icc_idr, node->id); + WARN_ON(!hlist_empty(&node->req_list)); + } + + mutex_unlock(&icc_lock); + + kfree(node); +} +EXPORT_SYMBOL_GPL(icc_node_destroy); + +/** + * icc_link_create() - create a link between two nodes + * @node: source node id + * @dst_id: destination node id + * + * Create a link between two nodes. The nodes might belong to different + * interconnect providers and the @dst_id node might not exist (if the + * provider driver has not probed yet). So just create the @dst_id node + * and when the actual provider driver is probed, the rest of the node + * data is filled. + * + * Return: 0 on success, or an error code otherwise + */ +int icc_link_create(struct icc_node *node, const int dst_id) +{ + struct icc_node *dst; + struct icc_node **new; + int ret = 0; + + if (!node->provider) + return -EINVAL; + + mutex_lock(&icc_lock); + + dst = node_find(dst_id); + if (!dst) { + dst = icc_node_create_nolock(dst_id); + + if (IS_ERR(dst)) { + ret = PTR_ERR(dst); + goto out; + } + } + + new = krealloc(node->links, + (node->num_links + 1) * sizeof(*node->links), + GFP_KERNEL); + if (!new) { + ret = -ENOMEM; + goto out; + } + + node->links = new; + node->links[node->num_links++] = dst; + +out: + mutex_unlock(&icc_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(icc_link_create); + +/** + * icc_link_destroy() - destroy a link between two nodes + * @src: pointer to source node + * @dst: pointer to destination node + * + * Return: 0 on success, or an error code otherwise + */ +int icc_link_destroy(struct icc_node *src, struct icc_node *dst) +{ + struct icc_node **new; + size_t slot; + int ret = 0; + + if (IS_ERR_OR_NULL(src)) + return -EINVAL; + + if (IS_ERR_OR_NULL(dst)) + return -EINVAL; + + mutex_lock(&icc_lock); + + for (slot = 0; slot < src->num_links; slot++) + if (src->links[slot] == dst) + break; + + if (WARN_ON(slot == src->num_links)) { + ret = -ENXIO; + goto out; + } + + src->links[slot] = src->links[--src->num_links]; + + new = krealloc(src->links, src->num_links * sizeof(*src->links), + GFP_KERNEL); + if (new) + src->links = new; + +out: + mutex_unlock(&icc_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(icc_link_destroy); + +/** + * icc_node_add() - add interconnect node to interconnect provider + * @node: pointer to the interconnect node + * @provider: pointer to the interconnect provider + */ +void icc_node_add(struct icc_node *node, struct icc_provider *provider) +{ + mutex_lock(&icc_lock); + + node->provider = provider; + list_add_tail(&node->node_list, &provider->nodes); + + mutex_unlock(&icc_lock); +} +EXPORT_SYMBOL_GPL(icc_node_add); + +/** + * icc_node_del() - delete interconnect node from interconnect provider + * @node: pointer to the interconnect node + */ +void icc_node_del(struct icc_node *node) +{ + mutex_lock(&icc_lock); + + list_del(&node->node_list); + + mutex_unlock(&icc_lock); +} +EXPORT_SYMBOL_GPL(icc_node_del); + +/** + * icc_provider_add() - add a new interconnect provider + * @provider: the interconnect provider that will be added into topology + * + * Return: 0 on success, or an error code otherwise + */ +int icc_provider_add(struct icc_provider *provider) +{ + if (WARN_ON(!provider->set)) + return -EINVAL; + + mutex_lock(&icc_lock); + + INIT_LIST_HEAD(&provider->nodes); + list_add_tail(&provider->provider_list, &icc_providers); + + mutex_unlock(&icc_lock); + + dev_dbg(provider->dev, "interconnect provider added to topology\n"); + + return 0; +} +EXPORT_SYMBOL_GPL(icc_provider_add); + +/** + * icc_provider_del() - delete previously added interconnect provider + * @provider: the interconnect provider that will be removed from topology + * + * Return: 0 on success, or an error code otherwise + */ +int icc_provider_del(struct icc_provider *provider) +{ + mutex_lock(&icc_lock); + if (provider->users) { + pr_warn("interconnect provider still has %d users\n", + provider->users); + mutex_unlock(&icc_lock); + return -EBUSY; + } + + if (!list_empty(&provider->nodes)) { + pr_warn("interconnect provider still has nodes\n"); + mutex_unlock(&icc_lock); + return -EBUSY; + } + + list_del(&provider->provider_list); + mutex_unlock(&icc_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(icc_provider_del); + +MODULE_AUTHOR("Georgi Djakov "); +MODULE_DESCRIPTION("Interconnect Driver Core"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h new file mode 100644 index 0000000000000000000000000000000000000000..78208a754181bda970fb4dd6d6d737eb29bfc90a --- /dev/null +++ b/include/linux/interconnect-provider.h @@ -0,0 +1,125 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2018, Linaro Ltd. + * Author: Georgi Djakov + */ + +#ifndef __LINUX_INTERCONNECT_PROVIDER_H +#define __LINUX_INTERCONNECT_PROVIDER_H + +#include + +#define icc_units_to_bps(bw) ((bw) * 1000ULL) + +struct icc_node; + +/** + * struct icc_provider - interconnect provider (controller) entity that might + * provide multiple interconnect controls + * + * @provider_list: list of the registered interconnect providers + * @nodes: internal list of the interconnect provider nodes + * @set: pointer to device specific set operation function + * @aggregate: pointer to device specific aggregate operation function + * @dev: the device this interconnect provider belongs to + * @users: count of active users + * @data: pointer to private data + */ +struct icc_provider { + struct list_head provider_list; + struct list_head nodes; + int (*set)(struct icc_node *src, struct icc_node *dst); + int (*aggregate)(struct icc_node *node, u32 avg_bw, u32 peak_bw, + u32 *agg_avg, u32 *agg_peak); + struct device *dev; + int users; + void *data; +}; + +/** + * struct icc_node - entity that is part of the interconnect topology + * + * @id: platform specific node id + * @name: node name used in debugfs + * @links: a list of targets pointing to where we can go next when traversing + * @num_links: number of links to other interconnect nodes + * @provider: points to the interconnect provider of this node + * @node_list: the list entry in the parent provider's "nodes" list + * @search_list: list used when walking the nodes graph + * @reverse: pointer to previous node when walking the nodes graph + * @is_traversed: flag that is used when walking the nodes graph + * @req_list: a list of QoS constraint requests associated with this node + * @avg_bw: aggregated value of average bandwidth requests from all consumers + * @peak_bw: aggregated value of peak bandwidth requests from all consumers + * @data: pointer to private data + */ +struct icc_node { + int id; + const char *name; + struct icc_node **links; + size_t num_links; + + struct icc_provider *provider; + struct list_head node_list; + struct list_head search_list; + struct icc_node *reverse; + u8 is_traversed:1; + struct hlist_head req_list; + u32 avg_bw; + u32 peak_bw; + void *data; +}; + +#if IS_ENABLED(CONFIG_INTERCONNECT) + +struct icc_node *icc_node_create(int id); +void icc_node_destroy(int id); +int icc_link_create(struct icc_node *node, const int dst_id); +int icc_link_destroy(struct icc_node *src, struct icc_node *dst); +void icc_node_add(struct icc_node *node, struct icc_provider *provider); +void icc_node_del(struct icc_node *node); +int icc_provider_add(struct icc_provider *provider); +int icc_provider_del(struct icc_provider *provider); + +#else + +static inline struct icc_node *icc_node_create(int id) +{ + return ERR_PTR(-ENOTSUPP); +} + +void icc_node_destroy(int id) +{ +} + +static inline int icc_link_create(struct icc_node *node, const int dst_id) +{ + return -ENOTSUPP; +} + +int icc_link_destroy(struct icc_node *src, struct icc_node *dst) +{ + return -ENOTSUPP; +} + +void icc_node_add(struct icc_node *node, struct icc_provider *provider) +{ +} + +void icc_node_del(struct icc_node *node) +{ +} + +static inline int icc_provider_add(struct icc_provider *provider) +{ + return -ENOTSUPP; +} + +static inline int icc_provider_del(struct icc_provider *provider) +{ + return -ENOTSUPP; +} + +#endif /* CONFIG_INTERCONNECT */ + +#endif /* __LINUX_INTERCONNECT_PROVIDER_H */ diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h new file mode 100644 index 0000000000000000000000000000000000000000..c331afb3a2c88d5f0be7a52e115a388c8f86ee5c --- /dev/null +++ b/include/linux/interconnect.h @@ -0,0 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2018-2019, Linaro Ltd. + * Author: Georgi Djakov + */ + +#ifndef __LINUX_INTERCONNECT_H +#define __LINUX_INTERCONNECT_H + +#include +#include + +/* macros for converting to icc units */ +#define Bps_to_icc(x) ((x) / 1000) +#define kBps_to_icc(x) (x) +#define MBps_to_icc(x) ((x) * 1000) +#define GBps_to_icc(x) ((x) * 1000 * 1000) +#define bps_to_icc(x) (1) +#define kbps_to_icc(x) ((x) / 8 + ((x) % 8 ? 1 : 0)) +#define Mbps_to_icc(x) ((x) * 1000 / 8) +#define Gbps_to_icc(x) ((x) * 1000 * 1000 / 8) + +struct icc_path; +struct device; + +#if IS_ENABLED(CONFIG_INTERCONNECT) + +struct icc_path *icc_get(struct device *dev, const int src_id, + const int dst_id); +void icc_put(struct icc_path *path); +int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw); + +#else + +static inline struct icc_path *icc_get(struct device *dev, const int src_id, + const int dst_id) +{ + return NULL; +} + +static inline void icc_put(struct icc_path *path) +{ +} + +static inline int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw) +{ + return 0; +} + +#endif /* CONFIG_INTERCONNECT */ + +#endif /* __LINUX_INTERCONNECT_H */