diff options
Diffstat (limited to 'drivers/thermal/intel/int340x_thermal/processor_thermal_wt_hint.c')
-rw-r--r-- | drivers/thermal/intel/int340x_thermal/processor_thermal_wt_hint.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/thermal/intel/int340x_thermal/processor_thermal_wt_hint.c b/drivers/thermal/intel/int340x_thermal/processor_thermal_wt_hint.c new file mode 100644 index 0000000000..9d5e4c169d --- /dev/null +++ b/drivers/thermal/intel/int340x_thermal/processor_thermal_wt_hint.c @@ -0,0 +1,255 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * processor thermal device interface for reading workload type hints + * from the user space. The hints are provided by the firmware. + * + * Operation: + * When user space enables workload type prediction: + * - Use mailbox to: + * Configure notification delay + * Enable processor thermal device interrupt + * + * - The predicted workload type can be read from MMIO: + * Offset 0x5B18 shows if there was an interrupt + * active for change in workload type and also + * predicted workload type. + * + * Two interface functions are provided to call when there is a + * thermal device interrupt: + * - proc_thermal_check_wt_intr(): + * Check if the interrupt is for change in workload type. Called from + * interrupt context. + * + * - proc_thermal_wt_intr_callback(): + * Callback for interrupt processing in thread context. This involves + * sending notification to user space that there is a change in the + * workload type. + * + * Copyright (c) 2023, Intel Corporation. + */ + +#include <linux/bitfield.h> +#include <linux/pci.h> +#include "processor_thermal_device.h" + +#define SOC_WT GENMASK_ULL(47, 40) + +#define SOC_WT_PREDICTION_INT_ENABLE_BIT 23 + +#define SOC_WT_PREDICTION_INT_ACTIVE BIT(2) + +/* + * Closest possible to 1 Second is 1024 ms with programmed time delay + * of 0x0A. + */ +static u8 notify_delay = 0x0A; +static u16 notify_delay_ms = 1024; + +static DEFINE_MUTEX(wt_lock); +static u8 wt_enable; + +/* Show current predicted workload type index */ +static ssize_t workload_type_index_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct proc_thermal_device *proc_priv; + struct pci_dev *pdev = to_pci_dev(dev); + u64 status = 0; + int wt; + + mutex_lock(&wt_lock); + if (!wt_enable) { + mutex_unlock(&wt_lock); + return -ENODATA; + } + + proc_priv = pci_get_drvdata(pdev); + + status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET); + + mutex_unlock(&wt_lock); + + wt = FIELD_GET(SOC_WT, status); + + return sysfs_emit(buf, "%d\n", wt); +} + +static DEVICE_ATTR_RO(workload_type_index); + +static ssize_t workload_hint_enable_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%d\n", wt_enable); +} + +static ssize_t workload_hint_enable_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pci_dev *pdev = to_pci_dev(dev); + u8 mode; + int ret; + + if (kstrtou8(buf, 10, &mode) || mode > 1) + return -EINVAL; + + mutex_lock(&wt_lock); + + if (mode) + ret = processor_thermal_mbox_interrupt_config(pdev, true, + SOC_WT_PREDICTION_INT_ENABLE_BIT, + notify_delay); + else + ret = processor_thermal_mbox_interrupt_config(pdev, false, + SOC_WT_PREDICTION_INT_ENABLE_BIT, 0); + + if (ret) + goto ret_enable_store; + + ret = size; + wt_enable = mode; + +ret_enable_store: + mutex_unlock(&wt_lock); + + return ret; +} + +static DEVICE_ATTR_RW(workload_hint_enable); + +static ssize_t notification_delay_ms_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%u\n", notify_delay_ms); +} + +static ssize_t notification_delay_ms_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pci_dev *pdev = to_pci_dev(dev); + u16 new_tw; + int ret; + u8 tm; + + /* + * Time window register value: + * Formula: (1 + x/4) * power(2,y) + * x = 2 msbs, that is [30:29] y = 5 [28:24] + * in INTR_CONFIG register. + * The result will be in milli seconds. + * Here, just keep x = 0, and just change y. + * First round up the user value to power of 2 and + * then take log2, to get "y" value to program. + */ + ret = kstrtou16(buf, 10, &new_tw); + if (ret) + return ret; + + if (!new_tw) + return -EINVAL; + + new_tw = roundup_pow_of_two(new_tw); + tm = ilog2(new_tw); + if (tm > 31) + return -EINVAL; + + mutex_lock(&wt_lock); + + /* If the workload hint was already enabled, then update with the new delay */ + if (wt_enable) + ret = processor_thermal_mbox_interrupt_config(pdev, true, + SOC_WT_PREDICTION_INT_ENABLE_BIT, + tm); + + if (!ret) { + ret = size; + notify_delay = tm; + notify_delay_ms = new_tw; + } + + mutex_unlock(&wt_lock); + + return ret; +} + +static DEVICE_ATTR_RW(notification_delay_ms); + +static struct attribute *workload_hint_attrs[] = { + &dev_attr_workload_type_index.attr, + &dev_attr_workload_hint_enable.attr, + &dev_attr_notification_delay_ms.attr, + NULL +}; + +static const struct attribute_group workload_hint_attribute_group = { + .attrs = workload_hint_attrs, + .name = "workload_hint" +}; + +/* + * Callback to check if the interrupt for prediction is active. + * Caution: Called from the interrupt context. + */ +bool proc_thermal_check_wt_intr(struct proc_thermal_device *proc_priv) +{ + u64 int_status; + + int_status = readq(proc_priv->mmio_base + SOC_WT_RES_INT_STATUS_OFFSET); + if (int_status & SOC_WT_PREDICTION_INT_ACTIVE) + return true; + + return false; +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_check_wt_intr, INT340X_THERMAL); + +/* Callback to notify user space */ +void proc_thermal_wt_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_WT_PREDICTION_INT_ACTIVE)) + return; + + sysfs_notify(&pdev->dev.kobj, "workload_hint", "workload_type_index"); +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_wt_intr_callback, INT340X_THERMAL); + +static bool workload_hint_created; + +int proc_thermal_wt_hint_add(struct pci_dev *pdev, struct proc_thermal_device *proc_priv) +{ + int ret; + + ret = sysfs_create_group(&pdev->dev.kobj, &workload_hint_attribute_group); + if (ret) + return ret; + + workload_hint_created = true; + + return 0; +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_wt_hint_add, INT340X_THERMAL); + +void proc_thermal_wt_hint_remove(struct pci_dev *pdev) +{ + mutex_lock(&wt_lock); + if (wt_enable) + processor_thermal_mbox_interrupt_config(pdev, false, + SOC_WT_PREDICTION_INT_ENABLE_BIT, + 0); + mutex_unlock(&wt_lock); + + if (workload_hint_created) + sysfs_remove_group(&pdev->dev.kobj, &workload_hint_attribute_group); + + workload_hint_created = false; +} +EXPORT_SYMBOL_NS_GPL(proc_thermal_wt_hint_remove, INT340X_THERMAL); + +MODULE_IMPORT_NS(INT340X_THERMAL); +MODULE_LICENSE("GPL"); |