diff options
Diffstat (limited to 'drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c')
-rw-r--r-- | drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c new file mode 100644 index 0000000000..a1a108407f --- /dev/null +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_power_floor.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Processor thermal device module for registering and processing + * power floor. When the hardware reduces the power to the minimum + * possible, the power floor is notified via an interrupt. + * + * Operation: + * When user space enables power floor reporting: + * - Use mailbox to: + * Enable processor thermal device interrupt + * + * - Current status of power floor is read from offset 0x5B18 + * bit 39. + * + * Two interface functions are provided to call when there is a + * thermal device interrupt: + * - proc_thermal_power_floor_intr(): + * Check if the interrupt is for change in power floor. + * Called from interrupt context. + * + * - proc_thermal_power_floor_intr_callback(): + * Callback for interrupt processing in thread context. This involves + * sending notification to user space that there is a change in the + * power floor status. + * + * Copyright (c) 2023, Intel Corporation. + */ + +#include <linux/pci.h> +#include "processor_thermal_device.h" + +#define SOC_POWER_FLOOR_STATUS BIT(39) +#define SOC_POWER_FLOOR_SHIFT 39 + +#define SOC_POWER_FLOOR_INT_ENABLE_BIT 31 +#define SOC_POWER_FLOOR_INT_ACTIVE BIT(3) + +int proc_thermal_read_power_floor_status(struct proc_thermal_device *proc_priv) +{ + u64 status = 0; + + status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET); + return (status & SOC_POWER_FLOOR_STATUS) >> SOC_POWER_FLOOR_SHIFT; +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_read_power_floor_status, INT340X_THERMAL); + +static bool enable_state; +static DEFINE_MUTEX(pf_lock); + +int proc_thermal_power_floor_set_state(struct proc_thermal_device *proc_priv, bool enable) +{ + int ret = 0; + + mutex_lock(&pf_lock); + if (enable_state == enable) + goto pf_unlock; + + /* + * Time window parameter is not applicable to power floor interrupt configuration. + * Hence use -1 for time window. + */ + ret = processor_thermal_mbox_interrupt_config(to_pci_dev(proc_priv->dev), enable, + SOC_POWER_FLOOR_INT_ENABLE_BIT, -1); + if (!ret) + enable_state = enable; + +pf_unlock: + mutex_unlock(&pf_lock); + + return ret; +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_power_floor_set_state, INT340X_THERMAL); + +bool proc_thermal_power_floor_get_state(struct proc_thermal_device *proc_priv) +{ + return enable_state; +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_power_floor_get_state, INT340X_THERMAL); + +/** + * proc_thermal_check_power_floor_intr() - Check power floor interrupt. + * @proc_priv: Processor thermal device instance. + * + * Callback to check if the interrupt for power floor is active. + * + * Context: Called from interrupt context. + * + * Return: true if power floor is active, false when not active. + */ +bool proc_thermal_check_power_floor_intr(struct proc_thermal_device *proc_priv) +{ + u64 int_status; + + int_status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET); + return !!(int_status & SOC_POWER_FLOOR_INT_ACTIVE); +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_check_power_floor_intr, INT340X_THERMAL); + +/** + * proc_thermal_power_floor_intr_callback() - Process power floor notification + * @pdev: PCI device instance + * @proc_priv: Processor thermal device instance. + * + * Check if the power floor interrupt is active, if active send notification to + * user space for the attribute "power_limits", so that user can read the attribute + * and take action. + * + * Context: Called from interrupt thread context. + * + * Return: None. + */ +void proc_thermal_power_floor_intr_callback(struct pci_dev *pdev, + struct proc_thermal_device *proc_priv) +{ + u64 status; + + status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET); + if (!(status & SOC_POWER_FLOOR_INT_ACTIVE)) + return; + + sysfs_notify(&pdev->dev.kobj, "power_limits", "power_floor_status"); +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_power_floor_intr_callback, INT340X_THERMAL); + +MODULE_IMPORT_NS(INT340X_THERMAL); +MODULE_LICENSE("GPL"); |