| // 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"); |