cpuquiet: sysfs interfaces

Change-Id: Idb454f7380c48e2f4bab20e6ae51fef577b0f6c5
Signed-off-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Reviewed-on: http://git-master/r/105267
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Tested-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com>

1 files changed, 290 insertions, 0 deletions

diff --git a/drivers/cpuquiet/sysfs.c b/drivers/cpuquiet/sysfs.c
new file mode 100644
index 000000000000..1e1c14865b24
--- /dev/null
+++ b/drivers/cpuquiet/sysfs.c
@@ -0,0 +1,290 @@
+/*
+ * Copyright (c) 2012 NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+#include <linux/cpuquiet.h>
+
+#include "cpuquiet.h"
+
+struct cpuquiet_dev {
+	unsigned int cpu;
+	struct kobject kobj;
+};
+
+struct cpuquiet_sysfs_attr {
+	struct attribute attr;
+	ssize_t (*show)(char *);
+	ssize_t (*store)(const char *, size_t count);
+};
+
+static struct kobject *cpuquiet_global_kobject;
+struct cpuquiet_dev *cpuquiet_cpu_devices[CONFIG_NR_CPUS];
+
+static ssize_t show_current_governor(char *buf)
+{
+	ssize_t ret;
+
+	mutex_lock(&cpuquiet_lock);
+
+	if (cpuquiet_curr_governor)
+		ret = sprintf(buf, "%s\n", cpuquiet_curr_governor->name);
+	else
+		ret = sprintf(buf, "none\n");
+
+	mutex_unlock(&cpuquiet_lock);
+
+	return ret;
+
+}
+
+static ssize_t store_current_governor(const char *buf, size_t count)
+{
+	char name[CPUQUIET_NAME_LEN];
+	struct cpuquiet_governor *gov;
+	int len = count, ret = -EINVAL;
+
+	if (!len || len >= sizeof(name))
+		return -EINVAL;
+
+	memcpy(name, buf, count);
+	name[len] = '\0';
+	if (name[len - 1] == '\n')
+		name[--len] = '\0';
+
+	mutex_lock(&cpuquiet_lock);
+	gov = cpuquiet_find_governor(name);
+	mutex_unlock(&cpuquiet_lock);
+
+	if (gov)
+		ret = cpuquiet_switch_governor(gov);
+
+	if (ret)
+		return ret;
+	else
+		return count;
+}
+
+static ssize_t available_governors_show(char *buf)
+{
+	ssize_t ret = 0, len;
+	struct cpuquiet_governor *gov;
+
+	mutex_lock(&cpuquiet_lock);
+	if (!list_empty(&cpuquiet_governors)) {
+		list_for_each_entry(gov, &cpuquiet_governors, governor_list) {
+			len = sprintf(buf, "%s ", gov->name);
+			buf += len;
+			ret += len;
+		}
+		buf--;
+		*buf = '\n';
+	} else
+		ret = sprintf(buf, "none\n");
+
+	mutex_unlock(&cpuquiet_lock);
+
+	return ret;
+}
+
+struct cpuquiet_sysfs_attr attr_current_governor = __ATTR(current_governor,
+			0644, show_current_governor, store_current_governor);
+struct cpuquiet_sysfs_attr attr_governors = __ATTR_RO(available_governors);
+
+
+static struct attribute *cpuquiet_default_attrs[] = {
+	&attr_current_governor.attr,
+	&attr_governors.attr,
+	NULL
+};
+
+static ssize_t cpuquiet_sysfs_show(struct kobject *kobj,
+			struct attribute *attr, char *buf)
+{
+	struct cpuquiet_sysfs_attr *cattr =
+			container_of(attr, struct cpuquiet_sysfs_attr, attr);
+
+	return cattr->show(buf);
+}
+
+static ssize_t cpuquiet_sysfs_store(struct kobject *kobj,
+			struct attribute *attr, const char *buf, size_t count)
+{
+	struct cpuquiet_sysfs_attr *cattr =
+			container_of(attr, struct cpuquiet_sysfs_attr, attr);
+
+	if (cattr->store)
+		return cattr->store(buf, count);
+
+	return -EINVAL;
+}
+
+static const struct sysfs_ops cpuquiet_sysfs_ops = {
+	.show = cpuquiet_sysfs_show,
+	.store = cpuquiet_sysfs_store,
+};
+
+static struct kobj_type ktype_cpuquiet_sysfs = {
+	.sysfs_ops = &cpuquiet_sysfs_ops,
+	.default_attrs = cpuquiet_default_attrs,
+};
+
+int cpuquiet_add_group(struct attribute_group *attrs)
+{
+	return sysfs_create_group(cpuquiet_global_kobject, attrs);
+}
+
+void cpuquiet_remove_group(struct attribute_group *attrs)
+{
+	sysfs_remove_group(cpuquiet_global_kobject, attrs);
+}
+
+int cpuquiet_kobject_init(struct kobject *kobj, struct kobj_type *type,
+				char *name)
+{
+	int err;
+
+	err = kobject_init_and_add(kobj, type, cpuquiet_global_kobject, name);
+	if (!err)
+		kobject_uevent(kobj, KOBJ_ADD);
+
+	return err;
+}
+
+int cpuquiet_cpu_kobject_init(struct kobject *kobj, struct kobj_type *type,
+				char *name, int cpu)
+{
+	int err;
+
+	err = kobject_init_and_add(kobj, type, &cpuquiet_cpu_devices[cpu]->kobj,
+					name);
+	if (!err)
+		kobject_uevent(kobj, KOBJ_ADD);
+
+	return err;
+}
+
+int cpuquiet_add_class_sysfs(struct sysdev_class *cls)
+{
+	int err;
+
+	cpuquiet_global_kobject = kzalloc(sizeof(*cpuquiet_global_kobject),
+						GFP_KERNEL);
+	if (!cpuquiet_global_kobject)
+		return -ENOMEM;
+
+	err = kobject_init_and_add(cpuquiet_global_kobject,
+			&ktype_cpuquiet_sysfs, &cls->kset.kobj, "cpuquiet");
+	if (!err)
+		kobject_uevent(cpuquiet_global_kobject, KOBJ_ADD);
+
+	return err;
+}
+
+
+struct cpuquiet_attr {
+	struct attribute attr;
+	ssize_t (*show)(unsigned int, char *);
+	ssize_t (*store)(unsigned int, const char *, size_t count);
+};
+
+
+static ssize_t cpuquiet_state_show(struct kobject *kobj,
+	struct attribute *attr, char *buf)
+{
+	struct cpuquiet_attr *cattr = container_of(attr,
+					struct cpuquiet_attr, attr);
+	struct cpuquiet_dev *dev = container_of(kobj,
+					struct cpuquiet_dev, kobj);
+
+	return cattr->show(dev->cpu, buf);
+}
+
+static ssize_t cpuquiet_state_store(struct kobject *kobj,
+	struct attribute *attr, const char *buf, size_t count)
+{
+	struct cpuquiet_attr *cattr = container_of(attr,
+					struct cpuquiet_attr, attr);
+	struct cpuquiet_dev *dev = container_of(kobj,
+					struct cpuquiet_dev, kobj);
+
+	if (cattr->store)
+		return cattr->store(dev->cpu, buf, count);
+
+	return -EINVAL;
+}
+
+static ssize_t show_active(unsigned int cpu, char *buf)
+{
+	return sprintf(buf, "%u\n", cpu_online(cpu));
+}
+
+static ssize_t store_active(unsigned int cpu, const char *value, size_t count)
+{
+	unsigned int active;
+	int ret;
+
+	if (!cpuquiet_curr_governor->store_active)
+		return -EINVAL;
+
+	ret = sscanf(value, "%u", &active);
+	if (ret != 1)
+		return -EINVAL;
+
+	cpuquiet_curr_governor->store_active(cpu, active);
+
+	return count;
+}
+
+struct cpuquiet_attr attr_active = __ATTR(active, 0644, show_active,
+						store_active);
+
+static struct attribute *cpuquiet_default_cpu_attrs[] = {
+	&attr_active.attr,
+	NULL
+};
+
+static const struct sysfs_ops cpuquiet_cpu_sysfs_ops = {
+	.show = cpuquiet_state_show,
+	.store = cpuquiet_state_store,
+};
+
+static struct kobj_type ktype_cpuquiet = {
+	.sysfs_ops = &cpuquiet_cpu_sysfs_ops,
+	.default_attrs = cpuquiet_default_cpu_attrs,
+};
+
+void cpuquiet_add_dev(struct sys_device *sys_dev, unsigned int cpu)
+{
+	struct cpuquiet_dev *dev;
+	int err;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	dev->cpu = cpu;
+	cpuquiet_cpu_devices[cpu] = dev;
+	err = kobject_init_and_add(&dev->kobj, &ktype_cpuquiet,
+				&sys_dev->kobj, "cpuquiet");
+	if (!err)
+		kobject_uevent(&dev->kobj, KOBJ_ADD);
+}
+
+void cpuquiet_remove_dev(unsigned int cpu)
+{
+	kobject_put(cpuquiet_cpu_devices[cpu]);
+}