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 umode_t fam15h_power_is_visible(struct kobject *kobj, 97 struct attribute *attr, 98 int index) 99 { 100 /* power1_input is only reported for Fam15h, Models 00h-0fh */ 101 if (attr == &dev_attr_power1_input.attr && 102 (boot_cpu_data.x86 != 0x15 || boot_cpu_data.x86_model > 0xf)) 103 return 0; 104 105 return attr->mode; 106 } 107 108 static struct attribute *fam15h_power_attrs[] = { 109 &dev_attr_power1_input.attr, 110 &dev_attr_power1_crit.attr, 111 NULL 112 }; 113 114 static const struct attribute_group fam15h_power_group = { 115 .attrs = fam15h_power_attrs, 116 .is_visible = fam15h_power_is_visible, 117 }; 118 __ATTRIBUTE_GROUPS(fam15h_power); 119 120 static bool fam15h_power_is_internal_node0(struct pci_dev *f4) 121 { 122 u32 val; 123 124 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3), 125 REG_NORTHBRIDGE_CAP, &val); 126 if ((val & BIT(29)) && ((val >> 30) & 3)) 127 return false; 128 129 return true; 130 } 131 132 /* 133 * Newer BKDG versions have an updated recommendation on how to properly 134 * initialize the running average range (was: 0xE, now: 0x9). This avoids 135 * counter saturations resulting in bogus power readings. 136 * We correct this value ourselves to cope with older BIOSes. 137 */ 138 static const struct pci_device_id affected_device[] = { 139 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }, 140 { 0 } 141 }; 142 143 static void tweak_runavg_range(struct pci_dev *pdev) 144 { 145 u32 val; 146 147 /* 148 * let this quirk apply only to the current version of the 149 * northbridge, since future versions may change the behavior 150 */ 151 if (!pci_match_id(affected_device, pdev)) 152 return; 153 154 pci_bus_read_config_dword(pdev->bus, 155 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), 156 REG_TDP_RUNNING_AVERAGE, &val); 157 if ((val & 0xf) != 0xe) 158 return; 159 160 val &= ~0xf; 161 val |= 0x9; 162 pci_bus_write_config_dword(pdev->bus, 163 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), 164 REG_TDP_RUNNING_AVERAGE, val); 165 } 166 167 #ifdef CONFIG_PM 168 static int fam15h_power_resume(struct pci_dev *pdev) 169 { 170 tweak_runavg_range(pdev); 171 return 0; 172 } 173 #else 174 #define fam15h_power_resume NULL 175 #endif 176 177 static void fam15h_power_init_data(struct pci_dev *f4, 178 struct fam15h_power_data *data) 179 { 180 u32 val; 181 u64 tmp; 182 183 pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val); 184 data->base_tdp = val >> 16; 185 tmp = val & 0xffff; 186 187 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5), 188 REG_TDP_LIMIT3, &val); 189 190 data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f); 191 tmp *= data->tdp_to_watts; 192 193 /* result not allowed to be >= 256W */ 194 if ((tmp >> 16) >= 256) 195 dev_warn(&f4->dev, 196 "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n", 197 (unsigned int) (tmp >> 16)); 198 199 /* convert to microWatt */ 200 data->processor_pwr_watts = (tmp * 15625) >> 10; 201 } 202 203 static int fam15h_power_probe(struct pci_dev *pdev, 204 const struct pci_device_id *id) 205 { 206 struct fam15h_power_data *data; 207 struct device *dev = &pdev->dev; 208 struct device *hwmon_dev; 209 210 /* 211 * though we ignore every other northbridge, we still have to 212 * do the tweaking on _each_ node in MCM processors as the counters 213 * are working hand-in-hand 214 */ 215 tweak_runavg_range(pdev); 216 217 if (!fam15h_power_is_internal_node0(pdev)) 218 return -ENODEV; 219 220 data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL); 221 if (!data) 222 return -ENOMEM; 223 224 fam15h_power_init_data(pdev, data); 225 data->pdev = pdev; 226 227 hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power", 228 data, 229 fam15h_power_groups); 230 return PTR_ERR_OR_ZERO(hwmon_dev); 231 } 232 233 static const struct pci_device_id fam15h_power_id_table[] = { 234 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }, 235 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) }, 236 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) }, 237 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) }, 238 {} 239 }; 240 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table); 241 242 static struct pci_driver fam15h_power_driver = { 243 .name = "fam15h_power", 244 .id_table = fam15h_power_id_table, 245 .probe = fam15h_power_probe, 246 .resume = fam15h_power_resume, 247 }; 248 249 module_pci_driver(fam15h_power_driver); 250