With "operating-points-v2" its possible to tell which devices share OPPs. We already have infrastructure to decode that information.
This patch adds following APIs: - of_get_cpus_sharing_opps: Returns cpumask of CPUs sharing OPPs (only valid with v2 bindings). - of_cpumask_init_opp_table: Initializes OPPs for all CPUs present in cpumask. - of_cpumask_free_opp_table: Frees OPPs for all CPUs present in cpumask.
- set_cpus_sharing_opps: Sets which CPUs share OPPs (only valid with old OPP bindings, as this information isn't present in DT).
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/base/power/opp.c | 175 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_opp.h | 23 +++++++ 2 files changed, 198 insertions(+)
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 0022453e4b60..e24502a2692f 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -11,6 +11,7 @@ * published by the Free Software Foundation. */
+#include <linux/cpu.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/err.h> @@ -1162,6 +1163,26 @@ void of_free_opp_table(struct device *dev) } EXPORT_SYMBOL_GPL(of_free_opp_table);
+void of_cpumask_free_opp_table(cpumask_var_t cpumask) +{ + struct device *cpu_dev; + int cpu; + + WARN_ON(cpumask_empty(cpumask)); + + for_each_cpu(cpu, cpumask) { + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) { + pr_err("%s: failed to get cpu%d device\n", __func__, + cpu); + continue; + } + + of_free_opp_table(cpu_dev); + } +} +EXPORT_SYMBOL_GPL(of_cpumask_free_opp_table); + /* Returns opp descriptor node from its phandle. Caller must do of_node_put() */ static struct device_node * _of_get_opp_desc_node_from_prop(struct device *dev, const struct property *prop) @@ -1178,6 +1199,31 @@ _of_get_opp_desc_node_from_prop(struct device *dev, const struct property *prop) return opp_np; }
+/* Returns opp descriptor node for a device. Caller must do of_node_put() */ +static struct device_node *_of_get_opp_desc_node(struct device *dev) +{ + const struct property *prop; + + prop = of_find_property(dev->of_node, "operating-points-v2", NULL); + if (!prop) + return ERR_PTR(-ENODEV); + if (!prop->value) + return ERR_PTR(-ENODATA); + + /* + * TODO: Support for multiple OPP tables. + * + * There should be only ONE phandle present in "operating-points-v2" + * property. + */ + if (prop->length != sizeof(__be32)) { + dev_err(dev, "%s: Invalid opp desc phandle\n", __func__); + return ERR_PTR(-EINVAL); + } + + return _of_get_opp_desc_node_from_prop(dev, prop); +} + /* Initializes OPP tables based on new bindings */ static int _of_init_opp_table_v2(struct device *dev, const struct property *prop) @@ -1338,4 +1384,133 @@ int of_init_opp_table(struct device *dev) return _of_init_opp_table_v2(dev, prop); } EXPORT_SYMBOL_GPL(of_init_opp_table); + +int of_cpumask_init_opp_table(cpumask_var_t cpumask) +{ + struct device *cpu_dev; + int cpu, ret = 0; + + WARN_ON(cpumask_empty(cpumask)); + + for_each_cpu(cpu, cpumask) { + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) { + pr_err("%s: failed to get cpu%d device\n", __func__, + cpu); + continue; + } + + ret = of_init_opp_table(cpu_dev); + if (ret) { + pr_err("%s: couldn't find opp table for cpu:%d, %d\n", + __func__, cpu, ret); + + /* Free all other OPPs */ + of_cpumask_free_opp_table(cpumask); + break; + } + } + + return ret; +} +EXPORT_SYMBOL_GPL(of_cpumask_init_opp_table); + +/* Required only for V1 bindings, as v2 can manage it from DT itself */ +int set_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask) +{ + struct device_list_opp *list_dev; + struct device_opp *dev_opp; + struct device *dev; + int cpu, ret = 0; + + rcu_read_lock(); + + dev_opp = _find_device_opp(cpu_dev); + if (IS_ERR(dev_opp)) { + ret = -EINVAL; + goto out_rcu_read_unlock; + } + + for_each_cpu(cpu, cpumask) { + if (cpu == cpu_dev->id) + continue; + + dev = get_cpu_device(cpu); + if (!dev) { + dev_err(cpu_dev, "%s: failed to get cpu%d device\n", + __func__, cpu); + continue; + } + + list_dev = _add_list_dev(dev, dev_opp); + if (!list_dev) { + dev_err(dev, "%s: failed to add list-dev for cpu%d device\n", + __func__, cpu); + continue; + } + } +out_rcu_read_unlock: + rcu_read_unlock(); + + return 0; +} +EXPORT_SYMBOL_GPL(set_cpus_sharing_opps); + +/* + * Works only for OPP v2 bindings. + * + * cpumask should be already set to mask of cpu_dev->id. + * Returns -ENOENT if operating-points-v2 bindings aren't supported. + */ +int of_get_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask) +{ + struct device_node *np, *tmp_np; + struct device *tcpu_dev; + int cpu, ret = 0; + + /* Get OPP descriptor node */ + np = _of_get_opp_desc_node(cpu_dev); + if (IS_ERR(np)) { + dev_dbg(cpu_dev, "%s: Couldn't find opp node: %ld\n", __func__, + PTR_ERR(np)); + return -ENOENT; + } + + /* OPPs are shared ? */ + if (!of_get_property(np, "opp-shared", NULL)) + goto put_cpu_node; + + for_each_possible_cpu(cpu) { + if (cpu == cpu_dev->id) + continue; + + tcpu_dev = get_cpu_device(cpu); + if (!tcpu_dev) { + dev_err(cpu_dev, "%s: failed to get cpu%d device\n", + __func__, cpu); + ret = -ENODEV; + goto put_cpu_node; + } + + /* Get OPP descriptor node */ + tmp_np = _of_get_opp_desc_node(tcpu_dev); + if (IS_ERR(tmp_np)) { + dev_info(tcpu_dev, "%s: Couldn't find opp node: %ld\n", + __func__, PTR_ERR(tmp_np)); + ret = -EINVAL; + goto put_cpu_node; + } + + /* CPUs are sharing opp node */ + if (np == tmp_np) + cpumask_set_cpu(cpu, cpumask); + + of_node_put(tmp_np); + } + +put_cpu_node: + of_node_put(np); + return ret; +} +EXPORT_SYMBOL_GPL(of_get_cpus_sharing_opps); #endif diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index 20324b579adc..bb52fae5b921 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -121,6 +121,10 @@ static inline struct srcu_notifier_head *dev_pm_opp_get_notifier( #if defined(CONFIG_PM_OPP) && defined(CONFIG_OF) int of_init_opp_table(struct device *dev); void of_free_opp_table(struct device *dev); +int of_cpumask_init_opp_table(cpumask_var_t cpumask); +void of_cpumask_free_opp_table(cpumask_var_t cpumask); +int of_get_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask); +int set_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask); #else static inline int of_init_opp_table(struct device *dev) { @@ -130,6 +134,25 @@ static inline int of_init_opp_table(struct device *dev) static inline void of_free_opp_table(struct device *dev) { } + +static inline int of_cpumask_init_opp_table(cpumask_var_t cpumask) +{ + return -ENOSYS; +} + +static inline void of_cpumask_free_opp_table(cpumask_var_t cpumask) +{ +} + +static inline int of_get_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask) +{ + return -ENOSYS; +} + +static inline int set_cpus_sharing_opps(struct device *cpu_dev, cpumask_var_t cpumask) +{ + return -ENOSYS; +} #endif
#endif /* __LINUX_OPP_H__ */