--- /dev/null
+What: /sys/firmware/opal/powercap
+Date: August 2017
+Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description: Powercap directory for Powernv (P8, P9) servers
+
+ Each folder in this directory contains a
+ power-cappable component.
+
+What: /sys/firmware/opal/powercap/system-powercap
+ /sys/firmware/opal/powercap/system-powercap/powercap-min
+ /sys/firmware/opal/powercap/system-powercap/powercap-max
+ /sys/firmware/opal/powercap/system-powercap/powercap-current
+Date: August 2017
+Contact: Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description: System powercap directory and attributes applicable for
+ Powernv (P8, P9) servers
+
+ This directory provides powercap information. It
+ contains below sysfs attributes:
+
+ - powercap-min : This file provides the minimum
+ possible powercap in Watt units
+
+ - powercap-max : This file provides the maximum
+ possible powercap in Watt units
+
+ - powercap-current : This file provides the current
+ powercap set on the system. Writing to this file
+ creates a request for setting a new-powercap. The
+ powercap requested must be between powercap-min
+ and powercap-max.
--- /dev/null
+/*
+ * PowerNV OPAL Powercap interface
+ *
+ * Copyright 2017 IBM Corp.
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "opal-powercap: " fmt
+
+#include <linux/of.h>
+#include <linux/kobject.h>
+#include <linux/slab.h>
+
+#include <asm/opal.h>
+
+DEFINE_MUTEX(powercap_mutex);
+
+static struct kobject *powercap_kobj;
+
+struct powercap_attr {
+ u32 handle;
+ struct kobj_attribute attr;
+};
+
+static struct pcap {
+ struct attribute_group pg;
+ struct powercap_attr *pattrs;
+} *pcaps;
+
+static ssize_t powercap_show(struct kobject *kobj, struct kobj_attribute *attr,
+ char *buf)
+{
+ struct powercap_attr *pcap_attr = container_of(attr,
+ struct powercap_attr, attr);
+ struct opal_msg msg;
+ u32 pcap;
+ int ret, token;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ pr_devel("Failed to get token\n");
+ return token;
+ }
+
+ ret = mutex_lock_interruptible(&powercap_mutex);
+ if (ret)
+ goto out_token;
+
+ ret = opal_get_powercap(pcap_attr->handle, token, (u32 *)__pa(&pcap));
+ switch (ret) {
+ case OPAL_ASYNC_COMPLETION:
+ ret = opal_async_wait_response(token, &msg);
+ if (ret) {
+ pr_devel("Failed to wait for the async response\n");
+ ret = -EIO;
+ goto out;
+ }
+ ret = opal_error_code(opal_get_async_rc(msg));
+ if (!ret) {
+ ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
+ if (ret < 0)
+ ret = -EIO;
+ }
+ break;
+ case OPAL_SUCCESS:
+ ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
+ if (ret < 0)
+ ret = -EIO;
+ break;
+ default:
+ ret = opal_error_code(ret);
+ }
+
+out:
+ mutex_unlock(&powercap_mutex);
+out_token:
+ opal_async_release_token(token);
+ return ret;
+}
+
+static ssize_t powercap_store(struct kobject *kobj,
+ struct kobj_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct powercap_attr *pcap_attr = container_of(attr,
+ struct powercap_attr, attr);
+ struct opal_msg msg;
+ u32 pcap;
+ int ret, token;
+
+ ret = kstrtoint(buf, 0, &pcap);
+ if (ret)
+ return ret;
+
+ token = opal_async_get_token_interruptible();
+ if (token < 0) {
+ pr_devel("Failed to get token\n");
+ return token;
+ }
+
+ ret = mutex_lock_interruptible(&powercap_mutex);
+ if (ret)
+ goto out_token;
+
+ ret = opal_set_powercap(pcap_attr->handle, token, pcap);
+ switch (ret) {
+ case OPAL_ASYNC_COMPLETION:
+ ret = opal_async_wait_response(token, &msg);
+ if (ret) {
+ pr_devel("Failed to wait for the async response\n");
+ ret = -EIO;
+ goto out;
+ }
+ ret = opal_error_code(opal_get_async_rc(msg));
+ if (!ret)
+ ret = count;
+ break;
+ case OPAL_SUCCESS:
+ ret = count;
+ break;
+ default:
+ ret = opal_error_code(ret);
+ }
+
+out:
+ mutex_unlock(&powercap_mutex);
+out_token:
+ opal_async_release_token(token);
+ return ret;
+}
+
+static void powercap_add_attr(int handle, const char *name,
+ struct powercap_attr *attr)
+{
+ attr->handle = handle;
+ sysfs_attr_init(&attr->attr.attr);
+ attr->attr.attr.name = name;
+ attr->attr.attr.mode = 0444;
+ attr->attr.show = powercap_show;
+}
+
+void __init opal_powercap_init(void)
+{
+ struct device_node *powercap, *node;
+ int i = 0;
+
+ powercap = of_find_compatible_node(NULL, NULL, "ibm,opal-powercap");
+ if (!powercap) {
+ pr_devel("Powercap node not found\n");
+ return;
+ }
+
+ pcaps = kcalloc(of_get_child_count(powercap), sizeof(*pcaps),
+ GFP_KERNEL);
+ if (!pcaps)
+ return;
+
+ powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
+ if (!powercap_kobj) {
+ pr_warn("Failed to create powercap kobject\n");
+ goto out_pcaps;
+ }
+
+ i = 0;
+ for_each_child_of_node(powercap, node) {
+ u32 cur, min, max;
+ int j = 0;
+ bool has_cur = false, has_min = false, has_max = false;
+
+ if (!of_property_read_u32(node, "powercap-min", &min)) {
+ j++;
+ has_min = true;
+ }
+
+ if (!of_property_read_u32(node, "powercap-max", &max)) {
+ j++;
+ has_max = true;
+ }
+
+ if (!of_property_read_u32(node, "powercap-current", &cur)) {
+ j++;
+ has_cur = true;
+ }
+
+ pcaps[i].pattrs = kcalloc(j, sizeof(struct powercap_attr),
+ GFP_KERNEL);
+ if (!pcaps[i].pattrs)
+ goto out_pcaps_pattrs;
+
+ pcaps[i].pg.attrs = kcalloc(j + 1, sizeof(struct attribute *),
+ GFP_KERNEL);
+ if (!pcaps[i].pg.attrs) {
+ kfree(pcaps[i].pattrs);
+ goto out_pcaps_pattrs;
+ }
+
+ j = 0;
+ pcaps[i].pg.name = node->name;
+ if (has_min) {
+ powercap_add_attr(min, "powercap-min",
+ &pcaps[i].pattrs[j]);
+ pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
+ j++;
+ }
+
+ if (has_max) {
+ powercap_add_attr(max, "powercap-max",
+ &pcaps[i].pattrs[j]);
+ pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
+ j++;
+ }
+
+ if (has_cur) {
+ powercap_add_attr(cur, "powercap-current",
+ &pcaps[i].pattrs[j]);
+ pcaps[i].pattrs[j].attr.attr.mode |= 0220;
+ pcaps[i].pattrs[j].attr.store = powercap_store;
+ pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
+ j++;
+ }
+
+ if (sysfs_create_group(powercap_kobj, &pcaps[i].pg)) {
+ pr_warn("Failed to create powercap attribute group %s\n",
+ pcaps[i].pg.name);
+ goto out_pcaps_pattrs;
+ }
+ i++;
+ }
+
+ return;
+
+out_pcaps_pattrs:
+ while (--i >= 0) {
+ kfree(pcaps[i].pattrs);
+ kfree(pcaps[i].pg.attrs);
+ }
+ kobject_put(powercap_kobj);
+out_pcaps:
+ kfree(pcaps);
+}
projects / mirror_ubuntu-artful-kernel.git / commitdiff