drivers/hwmon/fam15h_power.c

   1 /*
   2  * fam15h_power.c - AMD Family 15h processor power monitoring
   3  *
   4  * Copyright (c) 2011 Advanced Micro Devices, Inc.
   5  * Author: Andreas Herrmann <herrmann.der.user@googlemail.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 <herrmann.der.user@googlemail.com>");
  32 MODULE_LICENSE("GPL");
  33
  34 /* D18F3 */
  35 #define REG_NORTHBRIDGE_CAP             0xe8
  36
  37 /* D18F4 */
  38 #define REG_PROCESSOR_TDP               0x1b8
  39
  40 /* D18F5 */
  41 #define REG_TDP_RUNNING_AVERAGE         0xe0
  42 #define REG_TDP_LIMIT3                  0xe8
  43
  44 struct fam15h_power_data {
  45         struct pci_dev *pdev;
  46         unsigned int tdp_to_watts;
  47         unsigned int base_tdp;
  48         unsigned int processor_pwr_watts;
  49         unsigned int cpu_pwr_sample_ratio;
  50 };
  51
  52 static ssize_t show_power(struct device *dev,
  53                           struct device_attribute *attr, char *buf)
  54 {
  55         u32 val, tdp_limit, running_avg_range;
  56         s32 running_avg_capture;
  57         u64 curr_pwr_watts;
  58         struct fam15h_power_data *data = dev_get_drvdata(dev);
  59         struct pci_dev *f4 = data->pdev;
  60
  61         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
  62                                   REG_TDP_RUNNING_AVERAGE, &val);
  63
  64         /*
  65          * On Carrizo and later platforms, TdpRunAvgAccCap bit field
  66          * is extended to 4:31 from 4:25.
  67          */
  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);
  71         } else {
  72                 running_avg_capture = (val >> 4) & 0x3fffff;
  73                 running_avg_capture = sign_extend32(running_avg_capture, 21);
  74         }
  75
  76         running_avg_range = (val & 0xf) + 1;
  77
  78         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
  79                                   REG_TDP_LIMIT3, &val);
  80
  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;
  86
  87         /*
  88          * Convert to microWatt
  89          *
  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)
  93          */
  94         curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
  95         return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
  96 }
  97 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
  98
  99 static ssize_t show_power_crit(struct device *dev,
 100                                struct device_attribute *attr, char *buf)
 101 {
 102         struct fam15h_power_data *data = dev_get_drvdata(dev);
 103
 104         return sprintf(buf, "%u\n", data->processor_pwr_watts);
 105 }
 106 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
 107
 108 static umode_t fam15h_power_is_visible(struct kobject *kobj,
 109                                        struct attribute *attr,
 110                                        int index)
 111 {
 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))
 115                 return 0;
 116
 117         return attr->mode;
 118 }
 119
 120 static struct attribute *fam15h_power_attrs[] = {
 121         &dev_attr_power1_input.attr,
 122         &dev_attr_power1_crit.attr,
 123         NULL
 124 };
 125
 126 static const struct attribute_group fam15h_power_group = {
 127         .attrs = fam15h_power_attrs,
 128         .is_visible = fam15h_power_is_visible,
 129 };
 130 __ATTRIBUTE_GROUPS(fam15h_power);
 131
 132 static bool should_load_on_this_node(struct pci_dev *f4)
 133 {
 134         u32 val;
 135
 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))
 139                 return false;
 140
 141         return true;
 142 }
 143
 144 /*
 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.
 149  */
 150 static const struct pci_device_id affected_device[] = {
 151         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 152         { 0 }
 153 };
 154
 155 static void tweak_runavg_range(struct pci_dev *pdev)
 156 {
 157         u32 val;
 158
 159         /*
 160          * let this quirk apply only to the current version of the
 161          * northbridge, since future versions may change the behavior
 162          */
 163         if (!pci_match_id(affected_device, pdev))
 164                 return;
 165
 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)
 170                 return;
 171
 172         val &= ~0xf;
 173         val |=  0x9;
 174         pci_bus_write_config_dword(pdev->bus,
 175                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 176                 REG_TDP_RUNNING_AVERAGE, val);
 177 }
 178
 179 #ifdef CONFIG_PM
 180 static int fam15h_power_resume(struct pci_dev *pdev)
 181 {
 182         tweak_runavg_range(pdev);
 183         return 0;
 184 }
 185 #else
 186 #define fam15h_power_resume NULL
 187 #endif
 188
 189 static void fam15h_power_init_data(struct pci_dev *f4,
 190                                              struct fam15h_power_data *data)
 191 {
 192         u32 val, eax, ebx, ecx, edx;
 193         u64 tmp;
 194
 195         pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
 196         data->base_tdp = val >> 16;
 197         tmp = val & 0xffff;
 198
 199         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
 200                                   REG_TDP_LIMIT3, &val);
 201
 202         data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
 203         tmp *= data->tdp_to_watts;
 204
 205         /* result not allowed to be >= 256W */
 206         if ((tmp >> 16) >= 256)
 207                 dev_warn(&f4->dev,
 208                          "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
 209                          (unsigned int) (tmp >> 16));
 210
 211         /* convert to microWatt */
 212         data->processor_pwr_watts = (tmp * 15625) >> 10;
 213
 214         cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 215
 216         /* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */
 217         if (!(edx & BIT(12)))
 218                 return;
 219
 220         /*
 221          * determine the ratio of the compute unit power accumulator
 222          * sample period to the PTSC counter period by executing CPUID
 223          * Fn8000_0007:ECX
 224          */
 225         data->cpu_pwr_sample_ratio = ecx;
 226 }
 227
 228 static int fam15h_power_probe(struct pci_dev *pdev,
 229                                         const struct pci_device_id *id)
 230 {
 231         struct fam15h_power_data *data;
 232         struct device *dev = &pdev->dev;
 233         struct device *hwmon_dev;
 234
 235         /*
 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
 239          */
 240         tweak_runavg_range(pdev);
 241
 242         if (!should_load_on_this_node(pdev))
 243                 return -ENODEV;
 244
 245         data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL);
 246         if (!data)
 247                 return -ENOMEM;
 248
 249         fam15h_power_init_data(pdev, data);
 250         data->pdev = pdev;
 251
 252         hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
 253                                                            data,
 254                                                            fam15h_power_groups);
 255         return PTR_ERR_OR_ZERO(hwmon_dev);
 256 }
 257
 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) },
 264         {}
 265 };
 266 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
 267
 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,
 273 };
 274
 275 module_pci_driver(fam15h_power_driver);