1 /* 2 * fam15h_power.c - AMD Family 15h processor power monitoring 3 * 4 * Copyright (c) 2011 Advanced Micro Devices, Inc. 5 * Author: Andreas Herrmann <andreas.herrmann3@amd.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 <andreas.herrmann3@amd.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 device *hwmon_dev; 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 pci_dev *f4 = to_pci_dev(dev); 58 struct fam15h_power_data *data = dev_get_drvdata(dev); 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 ssize_t show_name(struct device *dev, 97 struct device_attribute *attr, char *buf) 98 { 99 return sprintf(buf, "fam15h_power\n"); 100 } 101 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); 102 103 static struct attribute *fam15h_power_attrs[] = { 104 &dev_attr_power1_input.attr, 105 &dev_attr_power1_crit.attr, 106 &dev_attr_name.attr, 107 NULL 108 }; 109 110 static const struct attribute_group fam15h_power_attr_group = { 111 .attrs = fam15h_power_attrs, 112 }; 113 114 static bool __devinit fam15h_power_is_internal_node0(struct pci_dev *f4) 115 { 116 u32 val; 117 118 pci_bus_read_config_dword(f4->bus, PCI_DEVFN(PCI_SLOT(f4->devfn), 3), 119 REG_NORTHBRIDGE_CAP, &val); 120 if ((val & BIT(29)) && ((val >> 30) & 3)) 121 return false; 122 123 return true; 124 } 125 126 /* 127 * Newer BKDG versions have an updated recommendation on how to properly 128 * initialize the running average range (was: 0xE, now: 0x9). This avoids 129 * counter saturations resulting in bogus power readings. 130 * We correct this value ourselves to cope with older BIOSes. 131 */ 132 static DEFINE_PCI_DEVICE_TABLE(affected_device) = { 133 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }, 134 { 0 } 135 }; 136 137 static void __devinit tweak_runavg_range(struct pci_dev *pdev) 138 { 139 u32 val; 140 141 /* 142 * let this quirk apply only to the current version of the 143 * northbridge, since future versions may change the behavior 144 */ 145 if (!pci_match_id(affected_device, pdev)) 146 return; 147 148 pci_bus_read_config_dword(pdev->bus, 149 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), 150 REG_TDP_RUNNING_AVERAGE, &val); 151 if ((val & 0xf) != 0xe) 152 return; 153 154 val &= ~0xf; 155 val |= 0x9; 156 pci_bus_write_config_dword(pdev->bus, 157 PCI_DEVFN(PCI_SLOT(pdev->devfn), 5), 158 REG_TDP_RUNNING_AVERAGE, val); 159 } 160 161 static void __devinit 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, "Bogus value for ProcessorPwrWatts " 180 "(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 __devinit 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; 192 int err; 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 err = -ENODEV; 203 goto exit; 204 } 205 206 data = kzalloc(sizeof(struct fam15h_power_data), GFP_KERNEL); 207 if (!data) { 208 err = -ENOMEM; 209 goto exit; 210 } 211 fam15h_power_init_data(pdev, data); 212 dev = &pdev->dev; 213 214 dev_set_drvdata(dev, data); 215 err = sysfs_create_group(&dev->kobj, &fam15h_power_attr_group); 216 if (err) 217 goto exit_free_data; 218 219 data->hwmon_dev = hwmon_device_register(dev); 220 if (IS_ERR(data->hwmon_dev)) { 221 err = PTR_ERR(data->hwmon_dev); 222 goto exit_remove_group; 223 } 224 225 return 0; 226 227 exit_remove_group: 228 sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group); 229 exit_free_data: 230 kfree(data); 231 exit: 232 return err; 233 } 234 235 static void __devexit fam15h_power_remove(struct pci_dev *pdev) 236 { 237 struct device *dev; 238 struct fam15h_power_data *data; 239 240 dev = &pdev->dev; 241 data = dev_get_drvdata(dev); 242 hwmon_device_unregister(data->hwmon_dev); 243 sysfs_remove_group(&dev->kobj, &fam15h_power_attr_group); 244 dev_set_drvdata(dev, NULL); 245 kfree(data); 246 } 247 248 static DEFINE_PCI_DEVICE_TABLE(fam15h_power_id_table) = { 249 { PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) }, 250 {} 251 }; 252 MODULE_DEVICE_TABLE(pci, fam15h_power_id_table); 253 254 static struct pci_driver fam15h_power_driver = { 255 .name = "fam15h_power", 256 .id_table = fam15h_power_id_table, 257 .probe = fam15h_power_probe, 258 .remove = __devexit_p(fam15h_power_remove), 259 }; 260 261 module_pci_driver(fam15h_power_driver); 262