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 /* 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
  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 = ((u64)(tdp_limit +
  74                                 data->base_tdp)) << running_avg_range;
  75         curr_pwr_watts -= running_avg_capture;
  76         curr_pwr_watts *= data->tdp_to_watts;
  77
  78         /*
  79          * Convert to microWatt
  80          *
  81          * power is in Watt provided as fixed point integer with
  82          * scaling factor 1/(2^16).  For conversion we use
  83          * (10^6)/(2^16) = 15625/(2^10)
  84          */
  85         curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
  86         return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
  87 }
  88 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
  89
  90 static ssize_t show_power_crit(struct device *dev,
  91                                struct device_attribute *attr, char *buf)
  92 {
  93         struct fam15h_power_data *data = dev_get_drvdata(dev);
  94
  95         return sprintf(buf, "%u\n", data->processor_pwr_watts);
  96 }
  97 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
  98
  99 static ssize_t show_name(struct device *dev,
 100                          struct device_attribute *attr, char *buf)
 101 {
 102         return sprintf(buf, "fam15h_power\n");
 103 }
 104 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
 105
 106 static struct attribute *fam15h_power_attrs[] = {
 107         &dev_attr_power1_input.attr,
 108         &dev_attr_power1_crit.attr,
 109         &dev_attr_name.attr,
 110         NULL
 111 };
 112
 113 static const struct attribute_group fam15h_power_attr_group = {
 114         .attrs  = fam15h_power_attrs,
 115 };
 116
 117 static bool fam15h_power_is_internal_node0(struct pci_dev *f4)
 118 {
 119         u32 val;
 120
 121         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
 122                                   REG_NORTHBRIDGE_CAP, &val);
 123         if ((val & BIT(29)) && ((val >> 30) & 3))
 124                 return false;
 125
 126         return true;
 127 }
 128
 129 /*
 130  * Newer BKDG versions have an updated recommendation on how to properly
 131  * initialize the running average range (was: 0xE, now: 0x9). This avoids
 132  * counter saturations resulting in bogus power readings.
 133  * We correct this value ourselves to cope with older BIOSes.
 134  */
 135 static const struct pci_device_id affected_device[] = {
 136         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 137         { 0 }
 138 };
 139
 140 static void tweak_runavg_range(struct pci_dev *pdev)
 141 {
 142         u32 val;
 143
 144         /*
 145          * let this quirk apply only to the current version of the
 146          * northbridge, since future versions may change the behavior
 147          */
 148         if (!pci_match_id(affected_device, pdev))
 149                 return;
 150
 151         pci_bus_read_config_dword(pdev->bus,
 152                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 153                 REG_TDP_RUNNING_AVERAGE, &val);
 154         if ((val & 0xf) != 0xe)
 155                 return;
 156
 157         val &= ~0xf;
 158         val |=  0x9;
 159         pci_bus_write_config_dword(pdev->bus,
 160                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 161                 REG_TDP_RUNNING_AVERAGE, val);
 162 }
 163
 164 #ifdef CONFIG_PM
 165 static int fam15h_power_resume(struct pci_dev *pdev)
 166 {
 167         tweak_runavg_range(pdev);
 168         return 0;
 169 }
 170 #else
 171 #define fam15h_power_resume NULL
 172 #endif
 173
 174 static void fam15h_power_init_data(struct pci_dev *f4,
 175                                              struct fam15h_power_data *data)
 176 {
 177         u32 val;
 178         u64 tmp;
 179
 180         pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
 181         data->base_tdp = val >> 16;
 182         tmp = val & 0xffff;
 183
 184         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
 185                                   REG_TDP_LIMIT3, &val);
 186
 187         data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
 188         tmp *= data->tdp_to_watts;
 189
 190         /* result not allowed to be >= 256W */
 191         if ((tmp >> 16) >= 256)
 192                 dev_warn(&f4->dev,
 193                          "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
 194                          (unsigned int) (tmp >> 16));
 195
 196         /* convert to microWatt */
 197         data->processor_pwr_watts = (tmp * 15625) >> 10;
 198 }
 199
 200 static int fam15h_power_probe(struct pci_dev *pdev,
 201                                         const struct pci_device_id *id)
 202 {
 203         struct fam15h_power_data *data;
 204         struct device *dev = &pdev->dev;
 205         int err;
 206
 207         /*
 208          * though we ignore every other northbridge, we still have to
 209          * do the tweaking on _each_ node in MCM processors as the counters
 210          * are working hand-in-hand
 211          */
 212         tweak_runavg_range(pdev);
 213
 214         if (!fam15h_power_is_internal_node0(pdev))
 215                 return -ENODEV;
 216
 217         data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL);
 218         if (!data)
 219                 return -ENOMEM;
 220
 221         fam15h_power_init_data(pdev, data);
 222
 223         dev_set_drvdata(dev, data);
 224         err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group);
 225         if (err)
 226                 return err;
 227
 228         data->hwmon_dev = hwmon_device_register(dev);
 229         if (IS_ERR(data->hwmon_dev)) {
 230                 err = PTR_ERR(data->hwmon_dev);
 231                 goto exit_remove_group;
 232         }
 233
 234         return 0;
 235
 236 exit_remove_group:
 237         sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
 238         return err;
 239 }
 240
 241 static void fam15h_power_remove(struct pci_dev *pdev)
 242 {
 243         struct device *dev;
 244         struct fam15h_power_data *data;
 245
 246         dev = &pdev->dev;
 247         data = dev_get_drvdata(dev);
 248         hwmon_device_unregister(data->hwmon_dev);
 249         sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group);
 250 }
 251
 252 static const struct pci_device_id fam15h_power_id_table[] = {
 253         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 254         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
 255         {}
 256 };
 257 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
 258
 259 static struct pci_driver fam15h_power_driver = {
 260         .name = "fam15h_power",
 261         .id_table = fam15h_power_id_table,
 262         .probe = fam15h_power_probe,
 263         .remove = fam15h_power_remove,
 264         .resume = fam15h_power_resume,
 265 };
 266
 267 module_pci_driver(fam15h_power_driver);