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); 268