// SPDX-License-Identifier: GPL-2.0-or-later /* * k8temp.c - Linux kernel module for hardware monitoring * * Copyright (C) 2006 Rudolf Marek <r.marek@assembler.cz> * * Inspired from the w83785 and amd756 drivers. */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/pci.h> #include <linux/hwmon.h> #include <linux/err.h> #include <linux/mutex.h> #include <asm/processor.h> #define TEMP_FROM_REG(val) (((((val) >> 16) & 0xff) - 49) * 1000) #define REG_TEMP 0xe4 #define SEL_PLACE 0x40 #define SEL_CORE 0x04 struct k8temp_data { struct mutex update_lock; /* registers values */ u8 sensorsp; /* sensor presence bits - SEL_CORE, SEL_PLACE */ u8 swap_core_select; /* meaning of SEL_CORE is inverted */ u32 temp_offset; }; static const struct pci_device_id k8temp_ids[] = { { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) }, { 0 }, }; MODULE_DEVICE_TABLE(pci, k8temp_ids); static int is_rev_g_desktop(u8 model) { u32 brandidx; if (model < 0x69) return 0; if (model == 0xc1 || model == 0x6c || model == 0x7c) return 0; /* * Differentiate between AM2 and ASB1. * See "Constructing the processor Name String" in "Revision * Guide for AMD NPT Family 0Fh Processors" (33610). */ brandidx = cpuid_ebx(0x80000001); brandidx = (brandidx >> 9) & 0x1f; /* Single core */ if ((model == 0x6f || model == 0x7f) && (brandidx == 0x7 || brandidx == 0x9 || brandidx == 0xc)) return 0; /* Dual core */ if (model == 0x6b && (brandidx == 0xb || brandidx == 0xc)) return 0; return 1; } static umode_t k8temp_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr, int channel) { const struct k8temp_data *data = drvdata; if ((channel & 1) && !(data->sensorsp & SEL_PLACE)) return 0; if ((channel & 2) && !(data->sensorsp & SEL_CORE)) return 0; return 0444; } static int k8temp_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct k8temp_data *data = dev_get_drvdata(dev); struct pci_dev *pdev = to_pci_dev(dev->parent); int core, place; u32 temp; u8 tmp; core = (channel >> 1) & 1; place = channel & 1; core ^= data->swap_core_select; mutex_lock(&data->update_lock); pci_read_config_byte(pdev, REG_TEMP, &tmp); tmp &= ~(SEL_PLACE | SEL_CORE); if (core) tmp |= SEL_CORE; if (place) tmp |= SEL_PLACE; pci_write_config_byte(pdev, REG_TEMP, tmp); pci_read_config_dword(pdev, REG_TEMP, &temp); mutex_unlock(&data->update_lock); *val = TEMP_FROM_REG(temp) + data->temp_offset; return 0; } static const struct hwmon_ops k8temp_ops = { .is_visible = k8temp_is_visible, .read = k8temp_read, }; static const struct hwmon_channel_info *k8temp_info[] = { HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT, HWMON_T_INPUT, HWMON_T_INPUT, HWMON_T_INPUT), NULL }; static const struct hwmon_chip_info k8temp_chip_info = { .ops = &k8temp_ops, .info = k8temp_info, }; static int k8temp_probe(struct pci_dev *pdev, const struct pci_device_id *id) { u8 scfg; u32 temp; u8 model, stepping; struct k8temp_data *data; struct device *hwmon_dev; data = devm_kzalloc(&pdev->dev, sizeof(struct k8temp_data), GFP_KERNEL); if (!data) return -ENOMEM; model = boot_cpu_data.x86_model; stepping = boot_cpu_data.x86_stepping; /* feature available since SH-C0, exclude older revisions */ if ((model == 4 && stepping == 0) || (model == 5 && stepping <= 1)) return -ENODEV; /* * AMD NPT family 0fh, i.e. RevF and RevG: * meaning of SEL_CORE bit is inverted */ if (model >= 0x40) { data->swap_core_select = 1; dev_warn(&pdev->dev, "Temperature readouts might be wrong - check erratum #141\n"); } /* * RevG desktop CPUs (i.e. no socket S1G1 or ASB1 parts) need * additional offset, otherwise reported temperature is below * ambient temperature */ if (is_rev_g_desktop(model)) data->temp_offset = 21000; pci_read_config_byte(pdev, REG_TEMP, &scfg); scfg &= ~(SEL_PLACE | SEL_CORE); /* Select sensor 0, core0 */ pci_write_config_byte(pdev, REG_TEMP, scfg); pci_read_config_byte(pdev, REG_TEMP, &scfg); if (scfg & (SEL_PLACE | SEL_CORE)) { dev_err(&pdev->dev, "Configuration bit(s) stuck at 1!\n"); return -ENODEV; } scfg |= (SEL_PLACE | SEL_CORE); pci_write_config_byte(pdev, REG_TEMP, scfg); /* now we know if we can change core and/or sensor */ pci_read_config_byte(pdev, REG_TEMP, &data->sensorsp); if (data->sensorsp & SEL_PLACE) { scfg &= ~SEL_CORE; /* Select sensor 1, core0 */ pci_write_config_byte(pdev, REG_TEMP, scfg); pci_read_config_dword(pdev, REG_TEMP, &temp); scfg |= SEL_CORE; /* prepare for next selection */ if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */ data->sensorsp &= ~SEL_PLACE; } if (data->sensorsp & SEL_CORE) { scfg &= ~SEL_PLACE; /* Select sensor 0, core1 */ pci_write_config_byte(pdev, REG_TEMP, scfg); pci_read_config_dword(pdev, REG_TEMP, &temp); if (!((temp >> 16) & 0xff)) /* if temp is 0 -49C is unlikely */ data->sensorsp &= ~SEL_CORE; } mutex_init(&data->update_lock); hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, "k8temp", data, &k8temp_chip_info, NULL); return PTR_ERR_OR_ZERO(hwmon_dev); } static struct pci_driver k8temp_driver = { .name = "k8temp", .id_table = k8temp_ids, .probe = k8temp_probe, }; module_pci_driver(k8temp_driver); MODULE_AUTHOR("Rudolf Marek <r.marek@assembler.cz>"); MODULE_DESCRIPTION("AMD K8 core temperature monitor"); MODULE_LICENSE("GPL");