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 };
  50
  51 static ssize_t show_power(struct device *dev,
  52                           struct device_attribute *attr, char *buf)
  53 {
  54         u32 val, tdp_limit, running_avg_range;
  55         s32 running_avg_capture;
  56         u64 curr_pwr_watts;
  57         struct fam15h_power_data *data = dev_get_drvdata(dev);
  58         struct pci_dev *f4 = data->pdev;
  59
  60         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
  61                                   REG_TDP_RUNNING_AVERAGE, &val);
  62         running_avg_capture = (val >> 4) & 0x3fffff;
  63         running_avg_capture = sign_extend32(running_avg_capture, 21);
  64         running_avg_range = (val & 0xf) + 1;
  65
  66         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
  67                                   REG_TDP_LIMIT3, &val);
  68
  69         tdp_limit = val >> 16;
  70         curr_pwr_watts = ((u64)(tdp_limit +
  71                                 data->base_tdp)) << running_avg_range;
  72         curr_pwr_watts -= running_avg_capture;
  73         curr_pwr_watts *= data->tdp_to_watts;
  74
  75         /*
  76          * Convert to microWatt
  77          *
  78          * power is in Watt provided as fixed point integer with
  79          * scaling factor 1/(2^16).  For conversion we use
  80          * (10^6)/(2^16) = 15625/(2^10)
  81          */
  82         curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range);
  83         return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts);
  84 }
  85 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL);
  86
  87 static ssize_t show_power_crit(struct device *dev,
  88                                struct device_attribute *attr, char *buf)
  89 {
  90         struct fam15h_power_data *data = dev_get_drvdata(dev);
  91
  92         return sprintf(buf, "%u\n", data->processor_pwr_watts);
  93 }
  94 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL);
  95
  96 static struct attribute *fam15h_power_attrs[] = {
  97         &dev_attr_power1_input.attr,
  98         &dev_attr_power1_crit.attr,
  99         NULL
 100 };
 101
 102 ATTRIBUTE_GROUPS(fam15h_power);
 103
 104 static bool fam15h_power_is_internal_node0(struct pci_dev *f4)
 105 {
 106         u32 val;
 107
 108         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3),
 109                                   REG_NORTHBRIDGE_CAP, &val);
 110         if ((val & BIT(29)) && ((val >> 30) & 3))
 111                 return false;
 112
 113         return true;
 114 }
 115
 116 /*
 117  * Newer BKDG versions have an updated recommendation on how to properly
 118  * initialize the running average range (was: 0xE, now: 0x9). This avoids
 119  * counter saturations resulting in bogus power readings.
 120  * We correct this value ourselves to cope with older BIOSes.
 121  */
 122 static const struct pci_device_id affected_device[] = {
 123         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 124         { 0 }
 125 };
 126
 127 static void tweak_runavg_range(struct pci_dev *pdev)
 128 {
 129         u32 val;
 130
 131         /*
 132          * let this quirk apply only to the current version of the
 133          * northbridge, since future versions may change the behavior
 134          */
 135         if (!pci_match_id(affected_device, pdev))
 136                 return;
 137
 138         pci_bus_read_config_dword(pdev->bus,
 139                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 140                 REG_TDP_RUNNING_AVERAGE, &val);
 141         if ((val & 0xf) != 0xe)
 142                 return;
 143
 144         val &= ~0xf;
 145         val |=  0x9;
 146         pci_bus_write_config_dword(pdev->bus,
 147                 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5),
 148                 REG_TDP_RUNNING_AVERAGE, val);
 149 }
 150
 151 #ifdef CONFIG_PM
 152 static int fam15h_power_resume(struct pci_dev *pdev)
 153 {
 154         tweak_runavg_range(pdev);
 155         return 0;
 156 }
 157 #else
 158 #define fam15h_power_resume NULL
 159 #endif
 160
 161 static void fam15h_power_init_data(struct pci_dev *f4,
 162                                              struct fam15h_power_data *data)
 163 {
 164         u32 val;
 165         u64 tmp;
 166
 167         pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val);
 168         data->base_tdp = val >> 16;
 169         tmp = val & 0xffff;
 170
 171         pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5),
 172                                   REG_TDP_LIMIT3, &val);
 173
 174         data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f);
 175         tmp *= data->tdp_to_watts;
 176
 177         /* result not allowed to be >= 256W */
 178         if ((tmp >> 16) >= 256)
 179                 dev_warn(&f4->dev,
 180                          "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n",
 181                          (unsigned int) (tmp >> 16));
 182
 183         /* convert to microWatt */
 184         data->processor_pwr_watts = (tmp * 15625) >> 10;
 185 }
 186
 187 static int fam15h_power_probe(struct pci_dev *pdev,
 188                                         const struct pci_device_id *id)
 189 {
 190         struct fam15h_power_data *data;
 191         struct device *dev = &pdev->dev;
 192         struct device *hwmon_dev;
 193
 194         /*
 195          * though we ignore every other northbridge, we still have to
 196          * do the tweaking on _each_ node in MCM processors as the counters
 197          * are working hand-in-hand
 198          */
 199         tweak_runavg_range(pdev);
 200
 201         if (!fam15h_power_is_internal_node0(pdev))
 202                 return -ENODEV;
 203
 204         data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL);
 205         if (!data)
 206                 return -ENOMEM;
 207
 208         fam15h_power_init_data(pdev, data);
 209         data->pdev = pdev;
 210
 211         hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power",
 212                                                            data,
 213                                                            fam15h_power_groups);
 214         return PTR_ERR_OR_ZERO(hwmon_dev);
 215 }
 216
 217 static const struct pci_device_id fam15h_power_id_table[] = {
 218         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 219         { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
 220         {}
 221 };
 222 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table);
 223
 224 static struct pci_driver fam15h_power_driver = {
 225         .name = "fam15h_power",
 226         .id_table = fam15h_power_id_table,
 227         .probe = fam15h_power_probe,
 228         .resume = fam15h_power_resume,
 229 };
 230
 231 module_pci_driver(fam15h_power_driver);