From b9794a822281944ef3de5b1812a94cbdb8134320 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Fri, 28 Jan 2022 17:35:33 +0100 Subject: powercap/drivers/dtpm: Convert the init table section to a simple array The init table section is freed after the system booted. However the next changes will make per module the DTPM description, so the table won't be accessible when the module is loaded. In order to fix that, we should move the table to the data section where there are very few entries and that makes strange to add it there. The main goal of the table was to keep self-encapsulated code and we can keep it almost as it by using an array instead. Suggested-by: Ulf Hansson Reviewed-by: Ulf Hansson Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20220128163537.212248-2-daniel.lezcano@linaro.org --- include/linux/dtpm.h | 24 +++--------------------- 1 file changed, 3 insertions(+), 21 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dtpm.h b/include/linux/dtpm.h index d37e5d06a357..506048158a50 100644 --- a/include/linux/dtpm.h +++ b/include/linux/dtpm.h @@ -32,29 +32,11 @@ struct dtpm_ops { void (*release)(struct dtpm *); }; -typedef int (*dtpm_init_t)(void); - -struct dtpm_descr { - dtpm_init_t init; +struct dtpm_subsys_ops { + const char *name; + int (*init)(void); }; -/* Init section thermal table */ -extern struct dtpm_descr __dtpm_table[]; -extern struct dtpm_descr __dtpm_table_end[]; - -#define DTPM_TABLE_ENTRY(name, __init) \ - static struct dtpm_descr __dtpm_table_entry_##name \ - __used __section("__dtpm_table") = { \ - .init = __init, \ - } - -#define DTPM_DECLARE(name, init) DTPM_TABLE_ENTRY(name, init) - -#define for_each_dtpm_table(__dtpm) \ - for (__dtpm = __dtpm_table; \ - __dtpm < __dtpm_table_end; \ - __dtpm++) - static inline struct dtpm *to_dtpm(struct powercap_zone *zone) { return container_of(zone, struct dtpm, zone); -- cgit v1.2.3 From 3759ec678e8944dc2ea70cab77a300408f78ae27 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Fri, 28 Jan 2022 17:35:34 +0100 Subject: powercap/drivers/dtpm: Add hierarchy creation The DTPM framework is available but without a way to configure it. This change provides a way to create a hierarchy of DTPM node where the power consumption reflects the sum of the children's power consumption. It is up to the platform to specify an array of dtpm nodes where each element has a pointer to its parent, except the top most one. The type of the node gives the indication of which initialization callback to call. At this time, we can create a virtual node, where its purpose is to be a parent in the hierarchy, and a DT node where the name describes its path. In order to ensure a nice self-encapsulation, the DTPM subsys array contains a couple of initialization functions, one to setup the DTPM backend and one to initialize it up. With this approach, the DTPM framework has a very few material to export. Signed-off-by: Daniel Lezcano Reviewed-by: Ulf Hansson Link: https://lore.kernel.org/r/20220128163537.212248-3-daniel.lezcano@linaro.org --- drivers/powercap/Kconfig | 1 + drivers/powercap/dtpm.c | 190 ++++++++++++++++++++++++++++++++++++++++++++++- include/linux/dtpm.h | 15 ++++ 3 files changed, 203 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/drivers/powercap/Kconfig b/drivers/powercap/Kconfig index 8242e8c5ed77..b1ca339957e3 100644 --- a/drivers/powercap/Kconfig +++ b/drivers/powercap/Kconfig @@ -46,6 +46,7 @@ config IDLE_INJECT config DTPM bool "Power capping for Dynamic Thermal Power Management (EXPERIMENTAL)" + depends on OF help This enables support for the power capping for the dynamic thermal power management userspace engine. diff --git a/drivers/powercap/dtpm.c b/drivers/powercap/dtpm.c index 0e5c93443c70..414826a1509b 100644 --- a/drivers/powercap/dtpm.c +++ b/drivers/powercap/dtpm.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "dtpm_subsys.h" @@ -463,14 +464,197 @@ int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent) return 0; } -static int __init init_dtpm(void) +static struct dtpm *dtpm_setup_virtual(const struct dtpm_node *hierarchy, + struct dtpm *parent) { + struct dtpm *dtpm; + int ret; + + dtpm = kzalloc(sizeof(*dtpm), GFP_KERNEL); + if (!dtpm) + return ERR_PTR(-ENOMEM); + dtpm_init(dtpm, NULL); + + ret = dtpm_register(hierarchy->name, dtpm, parent); + if (ret) { + pr_err("Failed to register dtpm node '%s': %d\n", + hierarchy->name, ret); + kfree(dtpm); + return ERR_PTR(ret); + } + + return dtpm; +} + +static struct dtpm *dtpm_setup_dt(const struct dtpm_node *hierarchy, + struct dtpm *parent) +{ + struct device_node *np; + int i, ret; + + np = of_find_node_by_path(hierarchy->name); + if (!np) { + pr_err("Failed to find '%s'\n", hierarchy->name); + return ERR_PTR(-ENXIO); + } + + for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) { + + if (!dtpm_subsys[i]->setup) + continue; + + ret = dtpm_subsys[i]->setup(parent, np); + if (ret) { + pr_err("Failed to setup '%s': %d\n", dtpm_subsys[i]->name, ret); + of_node_put(np); + return ERR_PTR(ret); + } + } + + of_node_put(np); + + /* + * By returning a NULL pointer, we let know the caller there + * is no child for us as we are a leaf of the tree + */ + return NULL; +} + +typedef struct dtpm * (*dtpm_node_callback_t)(const struct dtpm_node *, struct dtpm *); + +dtpm_node_callback_t dtpm_node_callback[] = { + [DTPM_NODE_VIRTUAL] = dtpm_setup_virtual, + [DTPM_NODE_DT] = dtpm_setup_dt, +}; + +static int dtpm_for_each_child(const struct dtpm_node *hierarchy, + const struct dtpm_node *it, struct dtpm *parent) +{ + struct dtpm *dtpm; + int i, ret; + + for (i = 0; hierarchy[i].name; i++) { + + if (hierarchy[i].parent != it) + continue; + + dtpm = dtpm_node_callback[hierarchy[i].type](&hierarchy[i], parent); + + /* + * A NULL pointer means there is no children, hence we + * continue without going deeper in the recursivity. + */ + if (!dtpm) + continue; + + /* + * There are multiple reasons why the callback could + * fail. The generic glue is abstracting the backend + * and therefore it is not possible to report back or + * take a decision based on the error. In any case, + * if this call fails, it is not critical in the + * hierarchy creation, we can assume the underlying + * service is not found, so we continue without this + * branch in the tree but with a warning to log the + * information the node was not created. + */ + if (IS_ERR(dtpm)) { + pr_warn("Failed to create '%s' in the hierarchy\n", + hierarchy[i].name); + continue; + } + + ret = dtpm_for_each_child(hierarchy, &hierarchy[i], dtpm); + if (ret) + return ret; + } + + return 0; +} + +/** + * dtpm_create_hierarchy - Create the dtpm hierarchy + * @hierarchy: An array of struct dtpm_node describing the hierarchy + * + * The function is called by the platform specific code with the + * description of the different node in the hierarchy. It creates the + * tree in the sysfs filesystem under the powercap dtpm entry. + * + * The expected tree has the format: + * + * struct dtpm_node hierarchy[] = { + * [0] { .name = "topmost", type = DTPM_NODE_VIRTUAL }, + * [1] { .name = "package", .type = DTPM_NODE_VIRTUAL, .parent = &hierarchy[0] }, + * [2] { .name = "/cpus/cpu0", .type = DTPM_NODE_DT, .parent = &hierarchy[1] }, + * [3] { .name = "/cpus/cpu1", .type = DTPM_NODE_DT, .parent = &hierarchy[1] }, + * [4] { .name = "/cpus/cpu2", .type = DTPM_NODE_DT, .parent = &hierarchy[1] }, + * [5] { .name = "/cpus/cpu3", .type = DTPM_NODE_DT, .parent = &hierarchy[1] }, + * [6] { } + * }; + * + * The last element is always an empty one and marks the end of the + * array. + * + * Return: zero on success, a negative value in case of error. Errors + * are reported back from the underlying functions. + */ +int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table) +{ + const struct of_device_id *match; + const struct dtpm_node *hierarchy; + struct device_node *np; + int i, ret; + + if (pct) + return -EBUSY; + pct = powercap_register_control_type(NULL, "dtpm", NULL); if (IS_ERR(pct)) { pr_err("Failed to register control type\n"); - return PTR_ERR(pct); + ret = PTR_ERR(pct); + goto out_pct; + } + + ret = -ENODEV; + np = of_find_node_by_path("/"); + if (!np) + goto out_err; + + match = of_match_node(dtpm_match_table, np); + + of_node_put(np); + + if (!match) + goto out_err; + + hierarchy = match->data; + if (!hierarchy) { + ret = -EFAULT; + goto out_err; + } + + ret = dtpm_for_each_child(hierarchy, NULL, NULL); + if (ret) + goto out_err; + + for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) { + + if (!dtpm_subsys[i]->init) + continue; + + ret = dtpm_subsys[i]->init(); + if (ret) + pr_info("Failed to initialze '%s': %d", + dtpm_subsys[i]->name, ret); } return 0; + +out_err: + powercap_unregister_control_type(pct); +out_pct: + pct = NULL; + + return ret; } -late_initcall(init_dtpm); +EXPORT_SYMBOL_GPL(dtpm_create_hierarchy); diff --git a/include/linux/dtpm.h b/include/linux/dtpm.h index 506048158a50..f7a25c70dd4c 100644 --- a/include/linux/dtpm.h +++ b/include/linux/dtpm.h @@ -32,9 +32,23 @@ struct dtpm_ops { void (*release)(struct dtpm *); }; +struct device_node; + struct dtpm_subsys_ops { const char *name; int (*init)(void); + int (*setup)(struct dtpm *, struct device_node *); +}; + +enum DTPM_NODE_TYPE { + DTPM_NODE_VIRTUAL = 0, + DTPM_NODE_DT, +}; + +struct dtpm_node { + enum DTPM_NODE_TYPE type; + const char *name; + struct dtpm_node *parent; }; static inline struct dtpm *to_dtpm(struct powercap_zone *zone) @@ -52,4 +66,5 @@ void dtpm_unregister(struct dtpm *dtpm); int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent); +int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table); #endif -- cgit v1.2.3 From c404c64d64bc31bebe8a2015103671f7cd282731 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Sun, 30 Jan 2022 22:02:06 +0100 Subject: powercap/dtpm: Destroy hierarchy function The hierarchy creation function exits but without a destroy hierarchy function. Due to that, the modules creating the hierarchy can not be unloaded properly because they don't have an exit callback. Provide the dtpm_destroy_hierarchy() function to remove the previously created hierarchy. The function relies on all the release mechanisms implemented by the underlying powercap framework. Signed-off-by: Daniel Lezcano Reviewed-by: Ulf Hansson Link: https://lore.kernel.org/r/20220130210210.549877-4-daniel.lezcano@linaro.org --- drivers/powercap/dtpm.c | 43 +++++++++++++++++++++++++++++++++++++++++++ include/linux/dtpm.h | 3 +++ 2 files changed, 46 insertions(+) (limited to 'include/linux') diff --git a/drivers/powercap/dtpm.c b/drivers/powercap/dtpm.c index 7bddd25a6767..d9d74f981118 100644 --- a/drivers/powercap/dtpm.c +++ b/drivers/powercap/dtpm.c @@ -617,3 +617,46 @@ out_unlock: return ret; } EXPORT_SYMBOL_GPL(dtpm_create_hierarchy); + +static void __dtpm_destroy_hierarchy(struct dtpm *dtpm) +{ + struct dtpm *child, *aux; + + list_for_each_entry_safe(child, aux, &dtpm->children, sibling) + __dtpm_destroy_hierarchy(child); + + /* + * At this point, we know all children were removed from the + * recursive call before + */ + dtpm_unregister(dtpm); +} + +void dtpm_destroy_hierarchy(void) +{ + int i; + + mutex_lock(&dtpm_lock); + + if (!pct) + goto out_unlock; + + __dtpm_destroy_hierarchy(root); + + + for (i = 0; i < ARRAY_SIZE(dtpm_subsys); i++) { + + if (!dtpm_subsys[i]->exit) + continue; + + dtpm_subsys[i]->exit(); + } + + powercap_unregister_control_type(pct); + + pct = NULL; + +out_unlock: + mutex_unlock(&dtpm_lock); +} +EXPORT_SYMBOL_GPL(dtpm_destroy_hierarchy); diff --git a/include/linux/dtpm.h b/include/linux/dtpm.h index f7a25c70dd4c..a4a13514b730 100644 --- a/include/linux/dtpm.h +++ b/include/linux/dtpm.h @@ -37,6 +37,7 @@ struct device_node; struct dtpm_subsys_ops { const char *name; int (*init)(void); + void (*exit)(void); int (*setup)(struct dtpm *, struct device_node *); }; @@ -67,4 +68,6 @@ void dtpm_unregister(struct dtpm *dtpm); int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent); int dtpm_create_hierarchy(struct of_device_id *dtpm_match_table); + +void dtpm_destroy_hierarchy(void); #endif -- cgit v1.2.3