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957b309c SB |
1 | /* |
2 | * PowerNV OPAL Powercap interface | |
3 | * | |
4 | * Copyright 2017 IBM Corp. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
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 | ||
20 | DEFINE_MUTEX(powercap_mutex); | |
21 | ||
22 | static struct kobject *powercap_kobj; | |
23 | ||
24 | struct powercap_attr { | |
25 | u32 handle; | |
26 | struct kobj_attribute attr; | |
27 | }; | |
28 | ||
29 | static struct pcap { | |
30 | struct attribute_group pg; | |
31 | struct powercap_attr *pattrs; | |
32 | } *pcaps; | |
33 | ||
34 | static 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 | ||
78 | out: | |
79 | mutex_unlock(&powercap_mutex); | |
80 | out_token: | |
81 | opal_async_release_token(token); | |
82 | return ret; | |
83 | } | |
84 | ||
85 | static 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 | ||
129 | out: | |
130 | mutex_unlock(&powercap_mutex); | |
131 | out_token: | |
132 | opal_async_release_token(token); | |
133 | return ret; | |
134 | } | |
135 | ||
136 | static 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 | ||
146 | void __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 | ||
236 | out_pcaps_pattrs: | |
237 | while (--i >= 0) { | |
238 | kfree(pcaps[i].pattrs); | |
239 | kfree(pcaps[i].pg.attrs); | |
240 | } | |
241 | kobject_put(powercap_kobj); | |
242 | out_pcaps: | |
243 | kfree(pcaps); | |
244 | } |