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); 232