Commit 8d4d4e98 authored by Viresh Kumar's avatar Viresh Kumar Committed by Rafael J. Wysocki
Browse files

PM / OPP: Add helpers for initializing CPU OPPs 



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).

Reviewed-by: default avatarStephen Boyd <sboyd@codeaurora.org>
Reviewed-by: default avatarBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent ad656a6a

drivers/base/power/opp.c

+175 −0
Original line number Diff line number Diff line
@@ -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>
@@ -1195,6 +1196,26 @@ unlock: 
}

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)
@@ -1211,6 +1232,31 @@ _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)
@@ -1351,4 +1397,133 @@ 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_property_read_bool(np, "opp-shared"))

		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_err(tcpu_dev, "%s: Couldn't find opp node: %ld\n",

				__func__, PTR_ERR(tmp_np));

			ret = PTR_ERR(tmp_np);

			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

include/linux/pm_opp.h

+23 −0
Original line number Diff line number Diff line
@@ -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__ */

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