From cc80d10d6fcf6f47a2a3efe2c4139e50906a4764 Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Tue, 25 Aug 2020 20:01:50 +0300 Subject: [PATCH 1/3] interconnect: Add get_bw() callback The interconnect controller hardware may support querying the current bandwidth settings, so add a callback for providers to implement this functionality if supported. Link: https://lore.kernel.org/r/20200825170152.6434-2-georgi.djakov@linaro.org Reviewed-by: Saravana Kannan Signed-off-by: Georgi Djakov --- include/linux/interconnect-provider.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h index 4735518de515f..520f70fe5a313 100644 --- a/include/linux/interconnect-provider.h +++ b/include/linux/interconnect-provider.h @@ -38,6 +38,7 @@ struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec, * @aggregate: pointer to device specific aggregate operation function * @pre_aggregate: pointer to device specific function that is called * before the aggregation begins (optional) + * @get_bw: pointer to device specific function to get current bandwidth * @xlate: provider-specific callback for mapping nodes from phandle arguments * @dev: the device this interconnect provider belongs to * @users: count of active users @@ -51,6 +52,7 @@ struct icc_provider { int (*aggregate)(struct icc_node *node, u32 tag, u32 avg_bw, u32 peak_bw, u32 *agg_avg, u32 *agg_peak); void (*pre_aggregate)(struct icc_node *node); + int (*get_bw)(struct icc_node *node, u32 *avg, u32 *peak); struct icc_node* (*xlate)(struct of_phandle_args *spec, void *data); struct device *dev; int users; From b1d681d8d32499bcf284462d92aeb5f9fe72bf5b Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Tue, 25 Aug 2020 20:01:51 +0300 Subject: [PATCH 2/3] interconnect: Add sync state support The bootloaders often do some initial configuration of the interconnects in the system and we want to keep this configuration until all consumers have probed and expressed their bandwidth needs. This is because we don't want to change the configuration by starting to disable unused paths until every user had a chance to request the amount of bandwidth it needs. To accomplish this we will implement an interconnect specific sync_state callback which will synchronize (aggregate and set) the current bandwidth settings when all consumers have been probed. Link: https://lore.kernel.org/r/20200825170152.6434-3-georgi.djakov@linaro.org Reviewed-by: Saravana Kannan Signed-off-by: Georgi Djakov --- drivers/interconnect/core.c | 67 +++++++++++++++++++++++++++ include/linux/interconnect-provider.h | 5 ++ 2 files changed, 72 insertions(+) diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c index cf07491b7415b..b94c6c2b8ff96 100644 --- a/drivers/interconnect/core.c +++ b/drivers/interconnect/core.c @@ -26,6 +26,8 @@ static DEFINE_IDR(icc_idr); static LIST_HEAD(icc_providers); +static int providers_count; +static bool synced_state; static DEFINE_MUTEX(icc_lock); static struct dentry *icc_debugfs_dir; @@ -267,6 +269,12 @@ static int aggregate_requests(struct icc_node *node) } p->aggregate(node, r->tag, avg_bw, peak_bw, &node->avg_bw, &node->peak_bw); + + /* during boot use the initial bandwidth as a floor value */ + if (!synced_state) { + node->avg_bw = max(node->avg_bw, node->init_avg); + node->peak_bw = max(node->peak_bw, node->init_peak); + } } return 0; @@ -931,6 +939,19 @@ void icc_node_add(struct icc_node *node, struct icc_provider *provider) node->provider = provider; list_add_tail(&node->node_list, &provider->nodes); + /* get the initial bandwidth values and sync them with hardware */ + if (provider->get_bw) { + provider->get_bw(node, &node->init_avg, &node->init_peak); + } else { + node->init_avg = INT_MAX; + node->init_peak = INT_MAX; + } + node->avg_bw = node->init_avg; + node->peak_bw = node->init_peak; + provider->set(node, node); + node->avg_bw = 0; + node->peak_bw = 0; + mutex_unlock(&icc_lock); } EXPORT_SYMBOL_GPL(icc_node_add); @@ -1026,8 +1047,54 @@ int icc_provider_del(struct icc_provider *provider) } EXPORT_SYMBOL_GPL(icc_provider_del); +static int of_count_icc_providers(struct device_node *np) +{ + struct device_node *child; + int count = 0; + + for_each_available_child_of_node(np, child) { + if (of_property_read_bool(child, "#interconnect-cells")) + count++; + count += of_count_icc_providers(child); + } + of_node_put(np); + + return count; +} + +void icc_sync_state(struct device *dev) +{ + struct icc_provider *p; + struct icc_node *n; + static int count; + + count++; + + if (count < providers_count) + return; + + mutex_lock(&icc_lock); + synced_state = true; + list_for_each_entry(p, &icc_providers, provider_list) { + dev_dbg(p->dev, "interconnect provider is in synced state\n"); + list_for_each_entry(n, &p->nodes, node_list) { + if (n->init_avg || n->init_peak) { + aggregate_requests(n); + p->set(n, n); + } + } + } + mutex_unlock(&icc_lock); +} +EXPORT_SYMBOL_GPL(icc_sync_state); + static int __init icc_init(void) { + struct device_node *root = of_find_node_by_path("/"); + + providers_count = of_count_icc_providers(root); + of_node_put(root); + icc_debugfs_dir = debugfs_create_dir("interconnect", NULL); debugfs_create_file("interconnect_summary", 0444, icc_debugfs_dir, NULL, &icc_summary_fops); diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h index 520f70fe5a313..f713308b8a8f4 100644 --- a/include/linux/interconnect-provider.h +++ b/include/linux/interconnect-provider.h @@ -75,6 +75,8 @@ struct icc_provider { * @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 + * @init_avg: average bandwidth value that is read from the hardware during init + * @init_peak: peak bandwidth value that is read from the hardware during init * @data: pointer to private data */ struct icc_node { @@ -91,6 +93,8 @@ struct icc_node { struct hlist_head req_list; u32 avg_bw; u32 peak_bw; + u32 init_avg; + u32 init_peak; void *data; }; @@ -108,6 +112,7 @@ int icc_nodes_remove(struct icc_provider *provider); int icc_provider_add(struct icc_provider *provider); int icc_provider_del(struct icc_provider *provider); struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec); +void icc_sync_state(struct device *dev); #else From 7d3b0b0d8184ce4a20fd9f48cd12484139bec939 Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Tue, 25 Aug 2020 20:01:52 +0300 Subject: [PATCH 3/3] interconnect: qcom: Use icc_sync_state Lowering the bandwidth on the bus might have negative consequences if it's done before all consumers had a chance to cast their vote. Now by default the framework sets the bandwidth to maximum during boot. We need to use the icc_sync_state callback to notify the framework when all consumers are probed and there is no need to keep the bandwidth set to maximum anymore. Link: https://lore.kernel.org/r/20200825170152.6434-4-georgi.djakov@linaro.org Reviewed-by: Saravana Kannan Signed-off-by: Georgi Djakov --- drivers/interconnect/qcom/osm-l3.c | 1 + drivers/interconnect/qcom/sc7180.c | 1 + drivers/interconnect/qcom/sdm845.c | 1 + 3 files changed, 3 insertions(+) diff --git a/drivers/interconnect/qcom/osm-l3.c b/drivers/interconnect/qcom/osm-l3.c index 96fb9ff5ff2e8..ae955f164442b 100644 --- a/drivers/interconnect/qcom/osm-l3.c +++ b/drivers/interconnect/qcom/osm-l3.c @@ -268,6 +268,7 @@ static struct platform_driver osm_l3_driver = { .driver = { .name = "osm-l3", .of_match_table = osm_l3_of_match, + .sync_state = icc_sync_state, }, }; module_platform_driver(osm_l3_driver); diff --git a/drivers/interconnect/qcom/sc7180.c b/drivers/interconnect/qcom/sc7180.c index dcf493d079287..4c5d386492201 100644 --- a/drivers/interconnect/qcom/sc7180.c +++ b/drivers/interconnect/qcom/sc7180.c @@ -633,6 +633,7 @@ static struct platform_driver qnoc_driver = { .driver = { .name = "qnoc-sc7180", .of_match_table = qnoc_of_match, + .sync_state = icc_sync_state, }, }; module_platform_driver(qnoc_driver); diff --git a/drivers/interconnect/qcom/sdm845.c b/drivers/interconnect/qcom/sdm845.c index f6c7b969520d0..6aa39aad25557 100644 --- a/drivers/interconnect/qcom/sdm845.c +++ b/drivers/interconnect/qcom/sdm845.c @@ -559,6 +559,7 @@ static struct platform_driver qnoc_driver = { .driver = { .name = "qnoc-sdm845", .of_match_table = qnoc_of_match, + .sync_state = icc_sync_state, }, }; module_platform_driver(qnoc_driver);