1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * PowerNV OPAL Powercap interface
5 * Copyright 2017 IBM Corp.
8 #define pr_fmt(fmt) "opal-powercap: " fmt
11 #include <linux/kobject.h>
12 #include <linux/slab.h>
16 static DEFINE_MUTEX(powercap_mutex);
18 static struct kobject *powercap_kobj;
20 struct powercap_attr {
22 struct kobj_attribute attr;
26 struct attribute_group pg;
27 struct powercap_attr *pattrs;
30 static ssize_t powercap_show(struct kobject *kobj, struct kobj_attribute *attr,
33 struct powercap_attr *pcap_attr = container_of(attr,
34 struct powercap_attr, attr);
39 token = opal_async_get_token_interruptible();
41 pr_devel("Failed to get token\n");
45 ret = mutex_lock_interruptible(&powercap_mutex);
49 ret = opal_get_powercap(pcap_attr->handle, token, (u32 *)__pa(&pcap));
51 case OPAL_ASYNC_COMPLETION:
52 ret = opal_async_wait_response(token, &msg);
54 pr_devel("Failed to wait for the async response\n");
58 ret = opal_error_code(opal_get_async_rc(msg));
60 ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
66 ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
71 ret = opal_error_code(ret);
75 mutex_unlock(&powercap_mutex);
77 opal_async_release_token(token);
81 static ssize_t powercap_store(struct kobject *kobj,
82 struct kobj_attribute *attr, const char *buf,
85 struct powercap_attr *pcap_attr = container_of(attr,
86 struct powercap_attr, attr);
91 ret = kstrtoint(buf, 0, &pcap);
95 token = opal_async_get_token_interruptible();
97 pr_devel("Failed to get token\n");
101 ret = mutex_lock_interruptible(&powercap_mutex);
105 ret = opal_set_powercap(pcap_attr->handle, token, pcap);
107 case OPAL_ASYNC_COMPLETION:
108 ret = opal_async_wait_response(token, &msg);
110 pr_devel("Failed to wait for the async response\n");
114 ret = opal_error_code(opal_get_async_rc(msg));
122 ret = opal_error_code(ret);
126 mutex_unlock(&powercap_mutex);
128 opal_async_release_token(token);
132 static void powercap_add_attr(int handle, const char *name,
133 struct powercap_attr *attr)
135 attr->handle = handle;
136 sysfs_attr_init(&attr->attr.attr);
137 attr->attr.attr.name = name;
138 attr->attr.attr.mode = 0444;
139 attr->attr.show = powercap_show;
142 void __init opal_powercap_init(void)
144 struct device_node *powercap, *node;
147 powercap = of_find_compatible_node(NULL, NULL, "ibm,opal-powercap");
149 pr_devel("Powercap node not found\n");
153 pcaps = kcalloc(of_get_child_count(powercap), sizeof(*pcaps),
158 powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
159 if (!powercap_kobj) {
160 pr_warn("Failed to create powercap kobject\n");
165 for_each_child_of_node(powercap, node) {
168 bool has_cur = false, has_min = false, has_max = false;
170 if (!of_property_read_u32(node, "powercap-min", &min)) {
175 if (!of_property_read_u32(node, "powercap-max", &max)) {
180 if (!of_property_read_u32(node, "powercap-current", &cur)) {
185 pcaps[i].pattrs = kcalloc(j, sizeof(struct powercap_attr),
187 if (!pcaps[i].pattrs)
188 goto out_pcaps_pattrs;
190 pcaps[i].pg.attrs = kcalloc(j + 1, sizeof(struct attribute *),
192 if (!pcaps[i].pg.attrs) {
193 kfree(pcaps[i].pattrs);
194 goto out_pcaps_pattrs;
198 pcaps[i].pg.name = kasprintf(GFP_KERNEL, "%pOFn", node);
199 if (!pcaps[i].pg.name) {
200 kfree(pcaps[i].pattrs);
201 kfree(pcaps[i].pg.attrs);
202 goto out_pcaps_pattrs;
206 powercap_add_attr(min, "powercap-min",
207 &pcaps[i].pattrs[j]);
208 pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
213 powercap_add_attr(max, "powercap-max",
214 &pcaps[i].pattrs[j]);
215 pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
220 powercap_add_attr(cur, "powercap-current",
221 &pcaps[i].pattrs[j]);
222 pcaps[i].pattrs[j].attr.attr.mode |= 0220;
223 pcaps[i].pattrs[j].attr.store = powercap_store;
224 pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
228 if (sysfs_create_group(powercap_kobj, &pcaps[i].pg)) {
229 pr_warn("Failed to create powercap attribute group %s\n",
231 goto out_pcaps_pattrs;
240 kfree(pcaps[i].pattrs);
241 kfree(pcaps[i].pg.attrs);
242 kfree(pcaps[i].pg.name);
244 kobject_put(powercap_kobj);