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12#define pr_fmt(fmt) "opal-powercap: " fmt
13
14#include <linux/of.h>
15#include <linux/kobject.h>
16#include <linux/slab.h>
17
18#include <asm/opal.h>
19
20DEFINE_MUTEX(powercap_mutex);
21
22static struct kobject *powercap_kobj;
23
24struct powercap_attr {
25 u32 handle;
26 struct kobj_attribute attr;
27};
28
29static struct pcap {
30 struct attribute_group pg;
31 struct powercap_attr *pattrs;
32} *pcaps;
33
34static ssize_t powercap_show(struct kobject *kobj, struct kobj_attribute *attr,
35 char *buf)
36{
37 struct powercap_attr *pcap_attr = container_of(attr,
38 struct powercap_attr, attr);
39 struct opal_msg msg;
40 u32 pcap;
41 int ret, token;
42
43 token = opal_async_get_token_interruptible();
44 if (token < 0) {
45 pr_devel("Failed to get token\n");
46 return token;
47 }
48
49 ret = mutex_lock_interruptible(&powercap_mutex);
50 if (ret)
51 goto out_token;
52
53 ret = opal_get_powercap(pcap_attr->handle, token, (u32 *)__pa(&pcap));
54 switch (ret) {
55 case OPAL_ASYNC_COMPLETION:
56 ret = opal_async_wait_response(token, &msg);
57 if (ret) {
58 pr_devel("Failed to wait for the async response\n");
59 ret = -EIO;
60 goto out;
61 }
62 ret = opal_error_code(opal_get_async_rc(msg));
63 if (!ret) {
64 ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
65 if (ret < 0)
66 ret = -EIO;
67 }
68 break;
69 case OPAL_SUCCESS:
70 ret = sprintf(buf, "%u\n", be32_to_cpu(pcap));
71 if (ret < 0)
72 ret = -EIO;
73 break;
74 default:
75 ret = opal_error_code(ret);
76 }
77
78out:
79 mutex_unlock(&powercap_mutex);
80out_token:
81 opal_async_release_token(token);
82 return ret;
83}
84
85static ssize_t powercap_store(struct kobject *kobj,
86 struct kobj_attribute *attr, const char *buf,
87 size_t count)
88{
89 struct powercap_attr *pcap_attr = container_of(attr,
90 struct powercap_attr, attr);
91 struct opal_msg msg;
92 u32 pcap;
93 int ret, token;
94
95 ret = kstrtoint(buf, 0, &pcap);
96 if (ret)
97 return ret;
98
99 token = opal_async_get_token_interruptible();
100 if (token < 0) {
101 pr_devel("Failed to get token\n");
102 return token;
103 }
104
105 ret = mutex_lock_interruptible(&powercap_mutex);
106 if (ret)
107 goto out_token;
108
109 ret = opal_set_powercap(pcap_attr->handle, token, pcap);
110 switch (ret) {
111 case OPAL_ASYNC_COMPLETION:
112 ret = opal_async_wait_response(token, &msg);
113 if (ret) {
114 pr_devel("Failed to wait for the async response\n");
115 ret = -EIO;
116 goto out;
117 }
118 ret = opal_error_code(opal_get_async_rc(msg));
119 if (!ret)
120 ret = count;
121 break;
122 case OPAL_SUCCESS:
123 ret = count;
124 break;
125 default:
126 ret = opal_error_code(ret);
127 }
128
129out:
130 mutex_unlock(&powercap_mutex);
131out_token:
132 opal_async_release_token(token);
133 return ret;
134}
135
136static void powercap_add_attr(int handle, const char *name,
137 struct powercap_attr *attr)
138{
139 attr->handle = handle;
140 sysfs_attr_init(&attr->attr.attr);
141 attr->attr.attr.name = name;
142 attr->attr.attr.mode = 0444;
143 attr->attr.show = powercap_show;
144}
145
146void __init opal_powercap_init(void)
147{
148 struct device_node *powercap, *node;
149 int i = 0;
150
151 powercap = of_find_compatible_node(NULL, NULL, "ibm,opal-powercap");
152 if (!powercap) {
153 pr_devel("Powercap node not found\n");
154 return;
155 }
156
157 pcaps = kcalloc(of_get_child_count(powercap), sizeof(*pcaps),
158 GFP_KERNEL);
159 if (!pcaps)
160 return;
161
162 powercap_kobj = kobject_create_and_add("powercap", opal_kobj);
163 if (!powercap_kobj) {
164 pr_warn("Failed to create powercap kobject\n");
165 goto out_pcaps;
166 }
167
168 i = 0;
169 for_each_child_of_node(powercap, node) {
170 u32 cur, min, max;
171 int j = 0;
172 bool has_cur = false, has_min = false, has_max = false;
173
174 if (!of_property_read_u32(node, "powercap-min", &min)) {
175 j++;
176 has_min = true;
177 }
178
179 if (!of_property_read_u32(node, "powercap-max", &max)) {
180 j++;
181 has_max = true;
182 }
183
184 if (!of_property_read_u32(node, "powercap-current", &cur)) {
185 j++;
186 has_cur = true;
187 }
188
189 pcaps[i].pattrs = kcalloc(j, sizeof(struct powercap_attr),
190 GFP_KERNEL);
191 if (!pcaps[i].pattrs)
192 goto out_pcaps_pattrs;
193
194 pcaps[i].pg.attrs = kcalloc(j + 1, sizeof(struct attribute *),
195 GFP_KERNEL);
196 if (!pcaps[i].pg.attrs) {
197 kfree(pcaps[i].pattrs);
198 goto out_pcaps_pattrs;
199 }
200
201 j = 0;
202 pcaps[i].pg.name = node->name;
203 if (has_min) {
204 powercap_add_attr(min, "powercap-min",
205 &pcaps[i].pattrs[j]);
206 pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
207 j++;
208 }
209
210 if (has_max) {
211 powercap_add_attr(max, "powercap-max",
212 &pcaps[i].pattrs[j]);
213 pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
214 j++;
215 }
216
217 if (has_cur) {
218 powercap_add_attr(cur, "powercap-current",
219 &pcaps[i].pattrs[j]);
220 pcaps[i].pattrs[j].attr.attr.mode |= 0220;
221 pcaps[i].pattrs[j].attr.store = powercap_store;
222 pcaps[i].pg.attrs[j] = &pcaps[i].pattrs[j].attr.attr;
223 j++;
224 }
225
226 if (sysfs_create_group(powercap_kobj, &pcaps[i].pg)) {
227 pr_warn("Failed to create powercap attribute group %s\n",
228 pcaps[i].pg.name);
229 goto out_pcaps_pattrs;
230 }
231 i++;
232 }
233
234 return;
235
236out_pcaps_pattrs:
237 while (--i >= 0) {
238 kfree(pcaps[i].pattrs);
239 kfree(pcaps[i].pg.attrs);
240 }
241 kobject_put(powercap_kobj);
242out_pcaps:
243 kfree(pcaps);
244}
245
