In order to power down the heirarchy of the CPU domain, the domain needs
information about the CPUs in that domain hierarchy . A domain that has
sub-domains containing CPU devices, will need information about all the
CPUs in the sub-domains as well.
Introduce of_attach_cpu_pm_domain() to allow CPU domains to be attached
to its parent domain and the information on CPUs attached directly or
indirectly be bubbled up the hierarchy.
Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx>
---
drivers/base/power/cpu-pd.c | 96 ++++++++++++++++++++++++++++++++++++++++++++-
include/linux/cpu-pd.h | 3 ++
2 files changed, 97 insertions(+), 2 deletions(-)
diff --git a/drivers/base/power/cpu-pd.c b/drivers/base/power/cpu-pd.c
index 9758b8d..617ce54 100644
--- a/drivers/base/power/cpu-pd.c
+++ b/drivers/base/power/cpu-pd.c
@@ -18,6 +18,7 @@
#include <linux/device.h>
#include <linux/pm_runtime.h>
#include <linux/platform_device.h>
+#include <linux/pm_qos.h>
#include <linux/rculist.h>
#include <linux/slab.h>
@@ -44,6 +45,27 @@ struct cpu_pm_domain *to_cpu_pd(struct generic_pm_domain *d)
return res;
}
+/**
+ * get_cpus_in_domain() - Recursively parse CPUs in a domain.
+ */
+static void get_cpus_in_domain(struct generic_pm_domain *genpd,
+ struct cpumask *mask)
+{
+ struct gpd_link *link;
+ struct cpu_pm_domain *pd = to_cpu_pd(genpd);
+ struct generic_pm_domain *sd;
+
+ if (!cpumask_empty(pd->cpus) && mask != pd->cpus) {
+ cpumask_or(mask, pd->cpus, mask);
+ return;
+ }
+
+ list_for_each_entry(link, &genpd->master_links, master_node) {
+ sd = link->slave;
+ get_cpus_in_domain(sd, mask);
+ }
+}
+
static int cpu_pd_power_off(struct generic_pm_domain *genpd)
{
struct cpu_pm_domain *pd = to_cpu_pd(genpd);
@@ -81,7 +103,8 @@ static void run_cpu(void *unused)
pm_runtime_get_noresume(cpu_dev);
}
-static int of_pm_domain_attach_cpus(struct device_node *dn)
+static int of_pm_domain_attach_cpus(struct device_node *dn,
+ struct cpu_pm_domain *pd)
{
int cpuid, ret;
@@ -126,6 +149,7 @@ static int of_pm_domain_attach_cpus(struct device_node *dn)
} else {
pm_runtime_enable(cpu_dev);
dev_dbg(cpu_dev, "Attached CPU%d to domain\n", cpuid);
+ cpumask_set_cpu(cpuid, pd->cpus);
}
}
@@ -171,7 +195,7 @@ int of_register_cpu_pm_domain(struct device_node *dn,
pd->genpd->name);
/* Attach the CPUs to the CPU PM domain */
- ret = of_pm_domain_attach_cpus(dn);
+ ret = of_pm_domain_attach_cpus(dn, pd);
if (ret)
of_genpd_del_provider(dn);
@@ -213,6 +237,13 @@ struct generic_pm_domain *of_init_cpu_pm_domain(struct device_node *dn,
return ERR_PTR(-ENOMEM);
}
+ if (!zalloc_cpumask_var(&pd->cpus, GFP_KERNEL)) {
+ kfree(pd->genpd->name);
+ kfree(pd->genpd);
+ kfree(pd);
+ return ERR_PTR(-ENOMEM);
+ }
+
if (ops) {
pd->plat_ops.power_off = ops->power_off;
pd->plat_ops.power_on = ops->power_on;
@@ -222,6 +253,7 @@ struct generic_pm_domain *of_init_cpu_pm_domain(struct device_node *dn,
if (ret) {
kfree(pd->genpd->name);
kfree(pd->genpd);
+ kfree(pd->cpus);
kfree(pd);
return ERR_PTR(ret);
}
@@ -229,3 +261,63 @@ struct generic_pm_domain *of_init_cpu_pm_domain(struct device_node *dn,
return pd->genpd;
}
EXPORT_SYMBOL(of_init_cpu_pm_domain);
+
+/**
+ * of_attach_cpu_pm_domain() - Attach a CPU PM domain to its parent
+ * @dn: The device node of the CPU PM domain that needs to be attached
+ *
+ * The platform code can use this simplfied function to parse the domain
+ * provider of this device node and attach the genpd associated with @dn
+ * to it parents.
+ *
+ * Note: Both @dn and its domain provider must be initialized using
+ * of_init_cpu_pm_domain.
+ */
+int of_attach_cpu_pm_domain(struct device_node *dn)
+{
+ struct of_phandle_args args;
+ struct generic_pm_domain *genpd, *parent;
+ struct cpu_pm_domain *pd;
+ int ret;
+
+ args.np = dn;
+ args.args_count = 0;
+
+ genpd = of_genpd_get_from_provider(&args);
+ if (IS_ERR(genpd))
+ return -EINVAL;
+
+ if (!to_cpu_pd(genpd)) {
+ pr_warn("%s: domain %s is not a CPU domain\n",
+ __func__, genpd->name);
+ return -EINVAL;
+ }
+
+ ret = of_parse_phandle_with_args(dn, "power-domains",
+ "#power-domain-cells", 0, &args);
+ if (ret < 0)
+ return ret;
+
+ parent = of_genpd_get_from_provider(&args);
+ if (IS_ERR(parent))
+ return -EINVAL;
+
+ pd = to_cpu_pd(parent);
+ if (!pd) {
+ pr_warn("%s: domain (%s) parent (%s) is non-CPU domain\n",
+ __func__, genpd->name, parent->name);
+ return -EINVAL;
+ }
+
+ ret = pm_genpd_add_subdomain(genpd, parent);
+ if (ret) {
+ pr_err("%s: Unable to add sub-domain (%s) to parent (%s)\n",
+ __func__, genpd->name, parent->name);
+ return ret;
+ }
+
+ get_cpus_in_domain(parent, pd->cpus);
+
+ return 0;
+}
+EXPORT_SYMBOL(of_attach_cpu_pm_domain);
diff --git a/include/linux/cpu-pd.h b/include/linux/cpu-pd.h
index a2a217d..489ee2f 100644
--- a/include/linux/cpu-pd.h
+++ b/include/linux/cpu-pd.h
@@ -11,6 +11,7 @@
#ifndef __CPU_PD_H__
#define __CPU_PD_H__
+#include <linux/cpumask.h>
#include <linux/list.h>
#include <linux/of.h>
#include <linux/pm_domain.h>
@@ -25,8 +26,10 @@ struct cpu_pm_domain {
struct generic_pm_domain *genpd;
struct device_node *dn;
struct cpu_pd_ops plat_ops;
+ cpumask_var_t cpus;
};
struct generic_pm_domain *of_init_cpu_pm_domain(struct device_node *dn,
const struct cpu_pd_ops *ops);
+int of_attach_cpu_pm_domain(struct device_node *dn);
#endif /* __CPU_PD_H__ */
--
2.1.4
--
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