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>
30 MODULE_DESCRIPTION("AMD Family 15h CPU processor power monitor");
31 MODULE_AUTHOR("Andreas Herrmann <herrmann.der.user@googlemail.com>");
32 MODULE_LICENSE("GPL");
35 #define REG_NORTHBRIDGE_CAP 0xe8
38 #define REG_PROCESSOR_TDP 0x1b8
41 #define REG_TDP_RUNNING_AVERAGE 0xe0
42 #define REG_TDP_LIMIT3 0xe8
44 struct fam15h_power_data
{
46 unsigned int tdp_to_watts
;
47 unsigned int base_tdp
;
48 unsigned int processor_pwr_watts
;
49 unsigned int cpu_pwr_sample_ratio
;
52 static ssize_t
show_power(struct device
*dev
,
53 struct device_attribute
*attr
, char *buf
)
55 u32 val
, tdp_limit
, running_avg_range
;
56 s32 running_avg_capture
;
58 struct fam15h_power_data
*data
= dev_get_drvdata(dev
);
59 struct pci_dev
*f4
= data
->pdev
;
61 pci_bus_read_config_dword(f4
->bus
, PCI_DEVFN(PCI_SLOT(f4
->devfn
), 5),
62 REG_TDP_RUNNING_AVERAGE
, &val
);
65 * On Carrizo and later platforms, TdpRunAvgAccCap bit field
66 * is extended to 4:31 from 4:25.
68 if (boot_cpu_data
.x86
== 0x15 && boot_cpu_data
.x86_model
>= 0x60) {
69 running_avg_capture
= val
>> 4;
70 running_avg_capture
= sign_extend32(running_avg_capture
, 27);
72 running_avg_capture
= (val
>> 4) & 0x3fffff;
73 running_avg_capture
= sign_extend32(running_avg_capture
, 21);
76 running_avg_range
= (val
& 0xf) + 1;
78 pci_bus_read_config_dword(f4
->bus
, PCI_DEVFN(PCI_SLOT(f4
->devfn
), 5),
79 REG_TDP_LIMIT3
, &val
);
81 tdp_limit
= val
>> 16;
82 curr_pwr_watts
= ((u64
)(tdp_limit
+
83 data
->base_tdp
)) << running_avg_range
;
84 curr_pwr_watts
-= running_avg_capture
;
85 curr_pwr_watts
*= data
->tdp_to_watts
;
88 * Convert to microWatt
90 * power is in Watt provided as fixed point integer with
91 * scaling factor 1/(2^16). For conversion we use
92 * (10^6)/(2^16) = 15625/(2^10)
94 curr_pwr_watts
= (curr_pwr_watts
* 15625) >> (10 + running_avg_range
);
95 return sprintf(buf
, "%u\n", (unsigned int) curr_pwr_watts
);
97 static DEVICE_ATTR(power1_input
, S_IRUGO
, show_power
, NULL
);
99 static ssize_t
show_power_crit(struct device
*dev
,
100 struct device_attribute
*attr
, char *buf
)
102 struct fam15h_power_data
*data
= dev_get_drvdata(dev
);
104 return sprintf(buf
, "%u\n", data
->processor_pwr_watts
);
106 static DEVICE_ATTR(power1_crit
, S_IRUGO
, show_power_crit
, NULL
);
108 static umode_t
fam15h_power_is_visible(struct kobject
*kobj
,
109 struct attribute
*attr
,
112 /* power1_input is only reported for Fam15h, Models 00h-0fh */
113 if (attr
== &dev_attr_power1_input
.attr
&&
114 (boot_cpu_data
.x86
!= 0x15 || boot_cpu_data
.x86_model
> 0xf))
120 static struct attribute
*fam15h_power_attrs
[] = {
121 &dev_attr_power1_input
.attr
,
122 &dev_attr_power1_crit
.attr
,
126 static const struct attribute_group fam15h_power_group
= {
127 .attrs
= fam15h_power_attrs
,
128 .is_visible
= fam15h_power_is_visible
,
130 __ATTRIBUTE_GROUPS(fam15h_power
);
132 static bool should_load_on_this_node(struct pci_dev
*f4
)
136 pci_bus_read_config_dword(f4
->bus
, PCI_DEVFN(PCI_SLOT(f4
->devfn
), 3),
137 REG_NORTHBRIDGE_CAP
, &val
);
138 if ((val
& BIT(29)) && ((val
>> 30) & 3))
145 * Newer BKDG versions have an updated recommendation on how to properly
146 * initialize the running average range (was: 0xE, now: 0x9). This avoids
147 * counter saturations resulting in bogus power readings.
148 * We correct this value ourselves to cope with older BIOSes.
150 static const struct pci_device_id affected_device
[] = {
151 { PCI_VDEVICE(AMD
, PCI_DEVICE_ID_AMD_15H_NB_F4
) },
155 static void tweak_runavg_range(struct pci_dev
*pdev
)
160 * let this quirk apply only to the current version of the
161 * northbridge, since future versions may change the behavior
163 if (!pci_match_id(affected_device
, pdev
))
166 pci_bus_read_config_dword(pdev
->bus
,
167 PCI_DEVFN(PCI_SLOT(pdev
->devfn
), 5),
168 REG_TDP_RUNNING_AVERAGE
, &val
);
169 if ((val
& 0xf) != 0xe)
174 pci_bus_write_config_dword(pdev
->bus
,
175 PCI_DEVFN(PCI_SLOT(pdev
->devfn
), 5),
176 REG_TDP_RUNNING_AVERAGE
, val
);
180 static int fam15h_power_resume(struct pci_dev
*pdev
)
182 tweak_runavg_range(pdev
);
186 #define fam15h_power_resume NULL
189 static void fam15h_power_init_data(struct pci_dev
*f4
,
190 struct fam15h_power_data
*data
)
192 u32 val
, eax
, ebx
, ecx
, edx
;
195 pci_read_config_dword(f4
, REG_PROCESSOR_TDP
, &val
);
196 data
->base_tdp
= val
>> 16;
199 pci_bus_read_config_dword(f4
->bus
, PCI_DEVFN(PCI_SLOT(f4
->devfn
), 5),
200 REG_TDP_LIMIT3
, &val
);
202 data
->tdp_to_watts
= ((val
& 0x3ff) << 6) | ((val
>> 10) & 0x3f);
203 tmp
*= data
->tdp_to_watts
;
205 /* result not allowed to be >= 256W */
206 if ((tmp
>> 16) >= 256)
208 "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
209 (unsigned int) (tmp
>> 16));
211 /* convert to microWatt */
212 data
->processor_pwr_watts
= (tmp
* 15625) >> 10;
214 cpuid(0x80000007, &eax
, &ebx
, &ecx
, &edx
);
216 /* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
217 if (!(edx
& BIT(12)))
221 * determine the ratio of the compute unit power accumulator
222 * sample period to the PTSC counter period by executing CPUID
225 data
->cpu_pwr_sample_ratio
= ecx
;
228 static int fam15h_power_probe(struct pci_dev
*pdev
,
229 const struct pci_device_id
*id
)
231 struct fam15h_power_data
*data
;
232 struct device
*dev
= &pdev
->dev
;
233 struct device
*hwmon_dev
;
236 * though we ignore every other northbridge, we still have to
237 * do the tweaking on _each_ node in MCM processors as the counters
238 * are working hand-in-hand
240 tweak_runavg_range(pdev
);
242 if (!should_load_on_this_node(pdev
))
245 data
= devm_kzalloc(dev
, sizeof(struct fam15h_power_data
), GFP_KERNEL
);
249 fam15h_power_init_data(pdev
, data
);
252 hwmon_dev
= devm_hwmon_device_register_with_groups(dev
, "fam15h_power",
254 fam15h_power_groups
);
255 return PTR_ERR_OR_ZERO(hwmon_dev
);
258 static const struct pci_device_id fam15h_power_id_table
[] = {
259 { PCI_VDEVICE(AMD
, PCI_DEVICE_ID_AMD_15H_NB_F4
) },
260 { PCI_VDEVICE(AMD
, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4
) },
261 { PCI_VDEVICE(AMD
, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4
) },
262 { PCI_VDEVICE(AMD
, PCI_DEVICE_ID_AMD_16H_NB_F4
) },
263 { PCI_VDEVICE(AMD
, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4
) },
266 MODULE_DEVICE_TABLE(pci
, fam15h_power_id_table
);
268 static struct pci_driver fam15h_power_driver
= {
269 .name
= "fam15h_power",
270 .id_table
= fam15h_power_id_table
,
271 .probe
= fam15h_power_probe
,
272 .resume
= fam15h_power_resume
,
275 module_pci_driver(fam15h_power_driver
);