From 11f1ceca7031deefc1a34236ab7b94360016b71d Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Wed, 16 Jan 2019 18:10:56 +0200 Subject: interconnect: Add generic on-chip interconnect API This patch introduces a new API to get requirements and configure the interconnect buses across the entire chipset to fit with the current demand. The API is using a consumer/provider-based model, where the providers are the interconnect buses and the consumers could be various drivers. The consumers request interconnect resources (path) between endpoints and set the desired constraints on this data flow path. The providers receive requests from consumers and aggregate these requests for all master-slave pairs on that path. Then the providers configure each node along the path to support a bandwidth that satisfies all bandwidth requests that cross through that node. The topology could be complicated and multi-tiered and is SoC specific. Reviewed-by: Evan Green Signed-off-by: Georgi Djakov Signed-off-by: Greg Kroah-Hartman --- include/linux/interconnect-provider.h | 125 ++++++++++++++++++++++++++++++++++ include/linux/interconnect.h | 52 ++++++++++++++ 2 files changed, 177 insertions(+) create mode 100644 include/linux/interconnect-provider.h create mode 100644 include/linux/interconnect.h (limited to 'include') diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h new file mode 100644 index 000000000000..78208a754181 --- /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 000000000000..c331afb3a2c8 --- /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 */ -- cgit v1.2.3