81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* PCIe cooling device
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*
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* Copyright (C) 2023-2024 Intel Corporation
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*/
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#include <linux/build_bug.h>
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#include <linux/cleanup.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/pci-bwctrl.h>
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#include <linux/slab.h>
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#include <linux/sprintf.h>
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#include <linux/thermal.h>
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#define COOLING_DEV_TYPE_PREFIX "PCIe_Port_Link_Speed_"
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static int pcie_cooling_get_max_level(struct thermal_cooling_device *cdev, unsigned long *state)
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{
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struct pci_dev *port = cdev->devdata;
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/* cooling state 0 is same as the maximum PCIe speed */
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*state = port->subordinate->max_bus_speed - PCIE_SPEED_2_5GT;
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return 0;
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}
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static int pcie_cooling_get_cur_level(struct thermal_cooling_device *cdev, unsigned long *state)
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{
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struct pci_dev *port = cdev->devdata;
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/* cooling state 0 is same as the maximum PCIe speed */
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*state = cdev->max_state - (port->subordinate->cur_bus_speed - PCIE_SPEED_2_5GT);
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return 0;
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}
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static int pcie_cooling_set_cur_level(struct thermal_cooling_device *cdev, unsigned long state)
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{
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struct pci_dev *port = cdev->devdata;
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enum pci_bus_speed speed;
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/* cooling state 0 is same as the maximum PCIe speed */
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speed = (cdev->max_state - state) + PCIE_SPEED_2_5GT;
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return pcie_set_target_speed(port, speed, true);
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}
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static struct thermal_cooling_device_ops pcie_cooling_ops = {
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.get_max_state = pcie_cooling_get_max_level,
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.get_cur_state = pcie_cooling_get_cur_level,
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.set_cur_state = pcie_cooling_set_cur_level,
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};
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struct thermal_cooling_device *pcie_cooling_device_register(struct pci_dev *port)
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{
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char *name __free(kfree) =
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kasprintf(GFP_KERNEL, COOLING_DEV_TYPE_PREFIX "%s", pci_name(port));
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if (!name)
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return ERR_PTR(-ENOMEM);
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return thermal_cooling_device_register(name, port, &pcie_cooling_ops);
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}
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void pcie_cooling_device_unregister(struct thermal_cooling_device *cdev)
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{
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thermal_cooling_device_unregister(cdev);
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}
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/* For bus_speed <-> state arithmetic */
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static_assert(PCIE_SPEED_2_5GT + 1 == PCIE_SPEED_5_0GT);
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static_assert(PCIE_SPEED_5_0GT + 1 == PCIE_SPEED_8_0GT);
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static_assert(PCIE_SPEED_8_0GT + 1 == PCIE_SPEED_16_0GT);
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static_assert(PCIE_SPEED_16_0GT + 1 == PCIE_SPEED_32_0GT);
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static_assert(PCIE_SPEED_32_0GT + 1 == PCIE_SPEED_64_0GT);
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MODULE_AUTHOR("Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>");
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MODULE_DESCRIPTION("PCIe cooling driver");
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