1 /*
2 * fam15h_power.c - AMD Family 15h processor power monitoring
3 *
4 * Copyright (c) 2011 Advanced Micro Devices, Inc.
5 * Author: Andreas Herrmann <andreas.herrmann3@amd.com>
6 *
7 *
8 * This driver is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License; either
10 * version 2 of the License, or (at your option) any later version.
11 *
12 * This driver is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
15 * See the GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this driver; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include <linux/err.h>
22 #include <linux/hwmon.h>
23 #include <linux/hwmon-sysfs.h>
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/pci.h>
27 #include <linux/bitops.h>
28 #include <asm/processor.h>
29
30 MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
31 MODULE_AUTHOR("Andreas Herrmann <andreas.herrmann3@amd.com>");
32 MODULE_LICENSE("GPL");
33
34 /* Family 16h Northbridge's function 4 PCI ID */
35 #define PCI_DEVICE_ID_AMD_16H_NB_F4 0x1534
36
37 /* D18F3 */
38 #define REG_NORTHBRIDGE_CAP 0xe8
39
40 /* D18F4 */
41 #define REG_PROCESSOR_TDP 0x1b8
42
43 /* D18F5 */
44 #define REG_TDP_RUNNING_AVERAGE 0xe0
45 #define REG_TDP_LIMIT3 0xe8
46
47 struct fam15h_power_data {
48 struct device *hwmon_dev;
49 unsigned int tdp_to_watts;
50 unsigned int base_tdp;
51 unsigned int processor_pwr_watts;
52 };
53
show_power(struct device * dev,struct device_attribute * attr,char * buf)54 static ssize_t show_power(struct device *dev,
55 struct device_attribute *attr, char *buf)
56 {
57 u32 val, tdp_limit, running_avg_range;
58 s32 running_avg_capture;
59 u64 curr_pwr_watts;
60 struct pci_dev *f4 = to_pci_dev(dev);
61 struct fam15h_power_data *data = dev_get_drvdata(dev);
62
63 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
64 REG_TDP_RUNNING_AVERAGE, &val);
65 running_avg_capture = (val >> 4) & 0x3fffff;
66 running_avg_capture = sign_extend32(running_avg_capture, 21);
67 running_avg_range = (val & 0xf) + 1;
68
69 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
70 REG_TDP_LIMIT3, &val);
71
72 tdp_limit = val >> 16;
73 curr_pwr_watts = (tdp_limit + data->base_tdp) << running_avg_range;
74 curr_pwr_watts -= running_avg_capture;
75 curr_pwr_watts *= data->tdp_to_watts;
76
77 /*
78 * Convert to microWatt
79 *
80 * power is in Watt provided as fixed point integer with
81 * scaling factor 1/(2^16). For conversion we use
82 * (10^6)/(2^16) = 15625/(2^10)
83 */
84 curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
85 return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
86 }
87 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
88
show_power_crit(struct device * dev,struct device_attribute * attr,char * buf)89 static ssize_t show_power_crit(struct device *dev,
90 struct device_attribute *attr, char *buf)
91 {
92 struct fam15h_power_data *data = dev_get_drvdata(dev);
93
94 return sprintf(buf, "%u\n", data->processor_pwr_watts);
95 }
96 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
97
show_name(struct device * dev,struct device_attribute * attr,char * buf)98 static ssize_t show_name(struct device *dev,
99 struct device_attribute *attr, char *buf)
100 {
101 return sprintf(buf, "fam15h_power\n");
102 }
103 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
104
105 static struct attribute *fam15h_power_attrs[] = {
106 &dev_attr_power1_input.attr,
107 &dev_attr_power1_crit.attr,
108 &dev_attr_name.attr,
109 NULL
110 };
111
112 static const struct attribute_group fam15h_power_attr_group = {
113 .attrs = fam15h_power_attrs,
114 };
115
fam15h_power_is_internal_node0(struct pci_dev * f4)116 static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4)
117 {
118 u32 val;
119
120 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
121 REG_NORTHBRIDGE_CAP, &val);
122 if ((val & BIT(29)) && ((val >> 30) & 3))
123 return false;
124
125 return true;
126 }
127
128 /*
129 * Newer BKDG versions have an updated recommendation on how to properly
130 * initialize the running average range (was: 0xE, now: 0x9). This avoids
131 * counter saturations resulting in bogus power readings.
132 * We correct this value ourselves to cope with older BIOSes.
133 */
134 static const struct pci_device_id affected_device[] = {
135 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
136 { 0 }
137 };
138
tweak_runavg_range(struct pci_dev * pdev)139 static void tweak_runavg_range(struct pci_dev *pdev)
140 {
141 u32 val;
142
143 /*
144 * let this quirk apply only to the current version of the
145 * northbridge, since future versions may change the behavior
146 */
147 if (!pci_match_id(affected_device, pdev))
148 return;
149
150 pci_bus_read_config_dword(pdev->bus,
151 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
152 REG_TDP_RUNNING_AVERAGE, &val);
153 if ((val & 0xf) != 0xe)
154 return;
155
156 val &= ~0xf;
157 val |= 0x9;
158 pci_bus_write_config_dword(pdev->bus,
159 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
160 REG_TDP_RUNNING_AVERAGE, val);
161 }
162
163 #ifdef CONFIG_PM
fam15h_power_resume(struct pci_dev * pdev)164 static int fam15h_power_resume(struct pci_dev *pdev)
165 {
166 tweak_runavg_range(pdev);
167 return 0;
168 }
169 #else
170 #define fam15h_power_resume NULL
171 #endif
172
fam15h_power_init_data(struct pci_dev * f4,struct fam15h_power_data * data)173 static void __devinit fam15h_power_init_data(struct pci_dev *f4,
174 struct fam15h_power_data *data)
175 {
176 u32 val;
177 u64 tmp;
178
179 pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
180 data->base_tdp = val >> 16;
181 tmp = val & 0xffff;
182
183 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
184 REG_TDP_LIMIT3, &val);
185
186 data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
187 tmp *= data->tdp_to_watts;
188
189 /* result not allowed to be >= 256W */
190 if ((tmp >> 16) >= 256)
191 dev_warn(&f4->dev, "Bogus value for ProcessorPwrWatts "
192 "(processor_pwr_watts>=%u)\n",
193 (unsigned int) (tmp >> 16));
194
195 /* convert to microWatt */
196 data->processor_pwr_watts = (tmp * 15625) >> 10;
197 }
198
fam15h_power_probe(struct pci_dev * pdev,const struct pci_device_id * id)199 static int __devinit fam15h_power_probe(struct pci_dev *pdev,
200 const struct pci_device_id *id)
201 {
202 struct fam15h_power_data *data;
203 struct device *dev;
204 int err;
205
206 /*
207 * though we ignore every other northbridge, we still have to
208 * do the tweaking on _each_ node in MCM processors as the counters
209 * are working hand-in-hand
210 */
211 tweak_runavg_range(pdev);
212
213 if (!fam15h_power_is_internal_node0(pdev)) {
214 err = -ENODEV;
215 goto exit;
216 }
217
218 data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL);
219 if (!data) {
220 err = -ENOMEM;
221 goto exit;
222 }
223 fam15h_power_init_data(pdev, data);
224 dev = &pdev->dev;
225
226 dev_set_drvdata(dev, data);
227 err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
228 if (err)
229 goto exit_free_data;
230
231 data->hwmon_dev = hwmon_device_register(dev);
232 if (IS_ERR(data->hwmon_dev)) {
233 err = PTR_ERR(data->hwmon_dev);
234 goto exit_remove_group;
235 }
236
237 return 0;
238
239 exit_remove_group:
240 sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
241 exit_free_data:
242 kfree(data);
243 exit:
244 return err;
245 }
246
fam15h_power_remove(struct pci_dev * pdev)247 static void __devexit fam15h_power_remove(struct pci_dev *pdev)
248 {
249 struct device *dev;
250 struct fam15h_power_data *data;
251
252 dev = &pdev->dev;
253 data = dev_get_drvdata(dev);
254 hwmon_device_unregister(data->hwmon_dev);
255 sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
256 dev_set_drvdata(dev, NULL);
257 kfree(data);
258 }
259
260 static DEFINE_PCI_DEVICE_TABLE(fam15h_power_id_table) = {
261 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
262 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
263 {}
264 };
265 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
266
267 static struct pci_driver fam15h_power_driver = {
268 .name = "fam15h_power",
269 .id_table = fam15h_power_id_table,
270 .probe = fam15h_power_probe,
271 .remove = __devexit_p(fam15h_power_remove),
272 .resume = fam15h_power_resume,
273 };
274
fam15h_power_init(void)275 static int __init fam15h_power_init(void)
276 {
277 return pci_register_driver(&fam15h_power_driver);
278 }
279
fam15h_power_exit(void)280 static void __exit fam15h_power_exit(void)
281 {
282 pci_unregister_driver(&fam15h_power_driver);
283 }
284
285 module_init(fam15h_power_init)
286 module_exit(fam15h_power_exit)
287