blob: d90ee4fc2c6aa9edf767b3bef3810f320d41563d [file] [log] [blame]
/*
* 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 = kasprintf(GFP_KERNEL, "%pOFn", node);
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);
kfree(pcaps[i].pg.name);
}
kobject_put(powercap_kobj);
out_pcaps:
kfree(pcaps);
}