2 * fam15h_power.c - AMD Family 15h processor power monitoring
4 * Copyright (c) 2011 Advanced Micro Devices, Inc.
5 * Author: Andreas Herrmann <herrmann.der.user@googlemail.com>
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.
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.
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/>.
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>
31 MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
32 MODULE_AUTHOR("Andreas Herrmann <herrmann.der.user@googlemail.com>");
33 MODULE_LICENSE("GPL");
36 #define REG_NORTHBRIDGE_CAP 0xe8
39 #define REG_PROCESSOR_TDP 0x1b8
42 #define REG_TDP_RUNNING_AVERAGE 0xe0
43 #define REG_TDP_LIMIT3 0xe8
45 #define FAM15H_MIN_NUM_ATTRS 2
46 #define FAM15H_NUM_GROUPS 2
48 #define MSR_F15H_CU_MAX_PWR_ACCUMULATOR 0xc001007b
50 #define PCI_DEVICE_ID_AMD_15H_M70H_NB_F4 0x15b4
52 struct fam15h_power_data {
54 unsigned int tdp_to_watts;
55 unsigned int base_tdp;
56 unsigned int processor_pwr_watts;
57 unsigned int cpu_pwr_sample_ratio;
58 const struct attribute_group *groups[FAM15H_NUM_GROUPS];
59 struct attribute_group group;
60 /* maximum accumulated power of a compute unit */
64 static ssize_t show_power(struct device *dev,
65 struct device_attribute *attr, char *buf)
67 u32 val, tdp_limit, running_avg_range;
68 s32 running_avg_capture;
70 struct fam15h_power_data *data = dev_get_drvdata(dev);
71 struct pci_dev *f4 = data->pdev;
73 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
74 REG_TDP_RUNNING_AVERAGE, &val);
77 * On Carrizo and later platforms, TdpRunAvgAccCap bit field
78 * is extended to 4:31 from 4:25.
80 if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model >= 0x60) {
81 running_avg_capture = val >> 4;
82 running_avg_capture = sign_extend32(running_avg_capture, 27);
84 running_avg_capture = (val >> 4) & 0x3fffff;
85 running_avg_capture = sign_extend32(running_avg_capture, 21);
88 running_avg_range = (val & 0xf) + 1;
90 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
91 REG_TDP_LIMIT3, &val);
94 * On Carrizo and later platforms, ApmTdpLimit bit field
95 * is extended to 16:31 from 16:28.
97 if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model >= 0x60)
98 tdp_limit = val >> 16;
100 tdp_limit = (val >> 16) & 0x1fff;
102 curr_pwr_watts = ((u64)(tdp_limit +
103 data->base_tdp)) << running_avg_range;
104 curr_pwr_watts -= running_avg_capture;
105 curr_pwr_watts *= data->tdp_to_watts;
108 * Convert to microWatt
110 * power is in Watt provided as fixed point integer with
111 * scaling factor 1/(2^16). For conversion we use
112 * (10^6)/(2^16) = 15625/(2^10)
114 curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
115 return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
117 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
119 static ssize_t show_power_crit(struct device *dev,
120 struct device_attribute *attr, char *buf)
122 struct fam15h_power_data *data = dev_get_drvdata(dev);
124 return sprintf(buf, "%u\n", data->processor_pwr_watts);
126 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
128 static int fam15h_power_init_attrs(struct pci_dev *pdev,
129 struct fam15h_power_data *data)
131 int n = FAM15H_MIN_NUM_ATTRS;
132 struct attribute **fam15h_power_attrs;
133 struct cpuinfo_x86 *c = &boot_cpu_data;
135 if (c->x86 == 0x15 &&
136 (c->x86_model <= 0xf ||
137 (c->x86_model >= 0x60 && c->x86_model <= 0x7f)))
140 fam15h_power_attrs = devm_kcalloc(&pdev->dev, n,
141 sizeof(*fam15h_power_attrs),
144 if (!fam15h_power_attrs)
148 fam15h_power_attrs[n++] = &dev_attr_power1_crit.attr;
149 if (c->x86 == 0x15 &&
150 (c->x86_model <= 0xf ||
151 (c->x86_model >= 0x60 && c->x86_model <= 0x7f)))
152 fam15h_power_attrs[n++] = &dev_attr_power1_input.attr;
154 data->group.attrs = fam15h_power_attrs;
159 static bool should_load_on_this_node(struct pci_dev *f4)
163 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
164 REG_NORTHBRIDGE_CAP, &val);
165 if ((val & BIT(29)) && ((val >> 30) & 3))
172 * Newer BKDG versions have an updated recommendation on how to properly
173 * initialize the running average range (was: 0xE, now: 0x9). This avoids
174 * counter saturations resulting in bogus power readings.
175 * We correct this value ourselves to cope with older BIOSes.
177 static const struct pci_device_id affected_device[] = {
178 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
182 static void tweak_runavg_range(struct pci_dev *pdev)
187 * let this quirk apply only to the current version of the
188 * northbridge, since future versions may change the behavior
190 if (!pci_match_id(affected_device, pdev))
193 pci_bus_read_config_dword(pdev->bus,
194 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
195 REG_TDP_RUNNING_AVERAGE, &val);
196 if ((val & 0xf) != 0xe)
201 pci_bus_write_config_dword(pdev->bus,
202 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
203 REG_TDP_RUNNING_AVERAGE, val);
207 static int fam15h_power_resume(struct pci_dev *pdev)
209 tweak_runavg_range(pdev);
213 #define fam15h_power_resume NULL
216 static int fam15h_power_init_data(struct pci_dev *f4,
217 struct fam15h_power_data *data)
219 u32 val, eax, ebx, ecx, edx;
223 pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
224 data->base_tdp = val >> 16;
227 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
228 REG_TDP_LIMIT3, &val);
230 data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
231 tmp *= data->tdp_to_watts;
233 /* result not allowed to be >= 256W */
234 if ((tmp >> 16) >= 256)
236 "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
237 (unsigned int) (tmp >> 16));
239 /* convert to microWatt */
240 data->processor_pwr_watts = (tmp * 15625) >> 10;
242 ret = fam15h_power_init_attrs(f4, data);
246 cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
248 /* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
249 if (!(edx & BIT(12)))
253 * determine the ratio of the compute unit power accumulator
254 * sample period to the PTSC counter period by executing CPUID
257 data->cpu_pwr_sample_ratio = ecx;
259 if (rdmsrl_safe(MSR_F15H_CU_MAX_PWR_ACCUMULATOR, &tmp)) {
260 pr_err("Failed to read max compute unit power accumulator MSR\n");
264 data->max_cu_acc_power = tmp;
269 static int fam15h_power_probe(struct pci_dev *pdev,
270 const struct pci_device_id *id)
272 struct fam15h_power_data *data;
273 struct device *dev = &pdev->dev;
274 struct device *hwmon_dev;
278 * though we ignore every other northbridge, we still have to
279 * do the tweaking on _each_ node in MCM processors as the counters
280 * are working hand-in-hand
282 tweak_runavg_range(pdev);
284 if (!should_load_on_this_node(pdev))
287 data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL);
291 ret = fam15h_power_init_data(pdev, data);
297 data->groups[0] = &data->group;
299 hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
302 return PTR_ERR_OR_ZERO(hwmon_dev);
305 static const struct pci_device_id fam15h_power_id_table[] = {
306 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
307 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
308 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
309 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M70H_NB_F4) },
310 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
311 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
314 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
316 static struct pci_driver fam15h_power_driver = {
317 .name = "fam15h_power",
318 .id_table = fam15h_power_id_table,
319 .probe = fam15h_power_probe,
320 .resume = fam15h_power_resume,
323 module_pci_driver(fam15h_power_driver);