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 unsigned int cpu_pwr_sample_ratio; 50 }; 51 52 static ssize_t show_power(struct device *dev, 53 struct device_attribute *attr, char *buf) 54 { 55 u32 val, tdp_limit, running_avg_range; 56 s32 running_avg_capture; 57 u64 curr_pwr_watts; 58 struct fam15h_power_data *data = dev_get_drvdata(dev); 59 struct pci_dev *f4 = data->pdev; 60 61 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5), 62 REG_TDP_RUNNING_AVERAGE, &val); 63 64 /* 65 * On Carrizo and later platforms, TdpRunAvgAccCap bit field 66 * is extended to 4:31 from 4:25. 67 */ 68 if (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model >= 0x60) { 69 running_avg_capture = val >> 4; 70 running_avg_capture = sign_extend32(running_avg_capture, 27); 71 } else { 72 running_avg_capture = (val >> 4) & 0x3fffff; 73 running_avg_capture = sign_extend32(running_avg_capture, 21); 74 } 75 76 running_avg_range = (val & 0xf) + 1; 77 78 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5), 79 REG_TDP_LIMIT3, &val); 80 81 tdp_limit = val >> 16; 82 curr_pwr_watts = ((u64)(tdp_limit + 83 data->base_tdp)) << running_avg_range; 84 curr_pwr_watts -= running_avg_capture; 85 curr_pwr_watts *= data->tdp_to_watts; 86 87 /* 88 * Convert to microWatt 89 * 90 * power is in Watt provided as fixed point integer with 91 * scaling factor 1/(2^16). For conversion we use 92 * (10^6)/(2^16) = 15625/(2^10) 93 */ 94 curr_pwr_watts = (curr_pwr_watts * 15625) >> (10 + running_avg_range); 95 return sprintf(buf, "%u\n", (unsigned int) curr_pwr_watts); 96 } 97 static DEVICE_ATTR(power1_input, S_IRUGO, show_power, NULL); 98 99 static ssize_t show_power_crit(struct device *dev, 100 struct device_attribute *attr, char *buf) 101 { 102 struct fam15h_power_data *data = dev_get_drvdata(dev); 103 104 return sprintf(buf, "%u\n", data->processor_pwr_watts); 105 } 106 static DEVICE_ATTR(power1_crit, S_IRUGO, show_power_crit, NULL); 107 108 static umode_t fam15h_power_is_visible(struct kobject *kobj, 109 struct attribute *attr, 110 int index) 111 { 112 /* power1_input is only reported for Fam15h, Models 00h-0fh */ 113 if (attr == &dev_attr_power1_input.attr && 114 (boot_cpu_data.x86 != 0x15 || boot_cpu_data.x86_model > 0xf)) 115 return 0; 116 117 return attr->mode; 118 } 119 120 static struct attribute *fam15h_power_attrs[] = { 121 &dev_attr_power1_input.attr, 122 &dev_attr_power1_crit.attr, 123 NULL 124 }; 125 126 static const struct attribute_group fam15h_power_group = { 127 .attrs = fam15h_power_attrs, 128 .is_visible = fam15h_power_is_visible, 129 }; 130 __ATTRIBUTE_GROUPS(fam15h_power); 131 132 static bool should_load_on_this_node(struct pci_dev *f4) 133 { 134 u32 val; 135 136 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3), 137 REG_NORTHBRIDGE_CAP, &val); 138 if ((val & BIT(29)) && ((val >> 30) & 3)) 139 return false; 140 141 return true; 142 } 143 144 /* 145 * Newer BKDG versions have an updated recommendation on how to properly 146 * initialize the running average range (was: 0xE, now: 0x9). This avoids 147 * counter saturations resulting in bogus power readings. 148 * We correct this value ourselves to cope with older BIOSes. 149 */ 150 static const struct pci_device_id affected_device[] = { 151 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }, 152 { 0 } 153 }; 154 155 static void tweak_runavg_range(struct pci_dev *pdev) 156 { 157 u32 val; 158 159 /* 160 * let this quirk apply only to the current version of the 161 * northbridge, since future versions may change the behavior 162 */ 163 if (!pci_match_id(affected_device, pdev)) 164 return; 165 166 pci_bus_read_config_dword(pdev->bus, 167 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), 168 REG_TDP_RUNNING_AVERAGE, &val); 169 if ((val & 0xf) != 0xe) 170 return; 171 172 val &= ~0xf; 173 val |= 0x9; 174 pci_bus_write_config_dword(pdev->bus, 175 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), 176 REG_TDP_RUNNING_AVERAGE, val); 177 } 178 179 #ifdef CONFIG_PM 180 static int fam15h_power_resume(struct pci_dev *pdev) 181 { 182 tweak_runavg_range(pdev); 183 return 0; 184 } 185 #else 186 #define fam15h_power_resume NULL 187 #endif 188 189 static void fam15h_power_init_data(struct pci_dev *f4, 190 struct fam15h_power_data *data) 191 { 192 u32 val, eax, ebx, ecx, edx; 193 u64 tmp; 194 195 pci_read_config_dword(f4, REG_PROCESSOR_TDP, &val); 196 data->base_tdp = val >> 16; 197 tmp = val & 0xffff; 198 199 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 5), 200 REG_TDP_LIMIT3, &val); 201 202 data->tdp_to_watts = ((val & 0x3ff) << 6) | ((val >> 10) & 0x3f); 203 tmp *= data->tdp_to_watts; 204 205 /* result not allowed to be >= 256W */ 206 if ((tmp >> 16) >= 256) 207 dev_warn(&f4->dev, 208 "Bogus value for ProcessorPwrWatts (processor_pwr_watts>=%u)\n", 209 (unsigned int) (tmp >> 16)); 210 211 /* convert to microWatt */ 212 data->processor_pwr_watts = (tmp * 15625) >> 10; 213 214 cpuid(0x80000007, &eax, &ebx, &ecx, &edx); 215 216 /* CPUID Fn8000_0007:EDX[12] indicates to support accumulated power */ 217 if (!(edx & BIT(12))) 218 return; 219 220 /* 221 * determine the ratio of the compute unit power accumulator 222 * sample period to the PTSC counter period by executing CPUID 223 * Fn8000_0007:ECX 224 */ 225 data->cpu_pwr_sample_ratio = ecx; 226 } 227 228 static int fam15h_power_probe(struct pci_dev *pdev, 229 const struct pci_device_id *id) 230 { 231 struct fam15h_power_data *data; 232 struct device *dev = &pdev->dev; 233 struct device *hwmon_dev; 234 235 /* 236 * though we ignore every other northbridge, we still have to 237 * do the tweaking on _each_ node in MCM processors as the counters 238 * are working hand-in-hand 239 */ 240 tweak_runavg_range(pdev); 241 242 if (!should_load_on_this_node(pdev)) 243 return -ENODEV; 244 245 data = devm_kzalloc(dev, sizeof(struct fam15h_power_data), GFP_KERNEL); 246 if (!data) 247 return -ENOMEM; 248 249 fam15h_power_init_data(pdev, data); 250 data->pdev = pdev; 251 252 hwmon_dev = devm_hwmon_device_register_with_groups(dev, "fam15h_power", 253 data, 254 fam15h_power_groups); 255 return PTR_ERR_OR_ZERO(hwmon_dev); 256 } 257 258 static const struct pci_device_id fam15h_power_id_table[] = { 259 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }, 260 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) }, 261 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) }, 262 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) }, 263 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) }, 264 {} 265 }; 266 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table); 267 268 static struct pci_driver fam15h_power_driver = { 269 .name = "fam15h_power", 270 .id_table = fam15h_power_id_table, 271 .probe = fam15h_power_probe, 272 .resume = fam15h_power_resume, 273 }; 274 275 module_pci_driver(fam15h_power_driver); 276