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![Mario Limonciello](/assets/img/avatar_default.png)
When we walk up the device hierarchy in tb_acpi_add_link() make sure we
break the loop if the device has no parent. Otherwise we may crash the
kernel by dereferencing a NULL pointer.
Fixes: b2be2b05cf
("thunderbolt: Create device links from ACPI description")
Cc: stable@vger.kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
117 lines
2.9 KiB
C
117 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* ACPI support
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*
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* Copyright (C) 2020, Intel Corporation
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* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
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*/
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#include <linux/acpi.h>
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#include "tb.h"
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static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
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void **return_value)
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{
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struct fwnode_reference_args args;
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struct fwnode_handle *fwnode;
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struct tb_nhi *nhi = data;
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struct acpi_device *adev;
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struct pci_dev *pdev;
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struct device *dev;
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int ret;
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if (acpi_bus_get_device(handle, &adev))
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return AE_OK;
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fwnode = acpi_fwnode_handle(adev);
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ret = fwnode_property_get_reference_args(fwnode, "usb4-host-interface",
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NULL, 0, 0, &args);
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if (ret)
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return AE_OK;
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/* It needs to reference this NHI */
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if (nhi->pdev->dev.fwnode != args.fwnode)
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goto out_put;
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/*
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* Try to find physical device walking upwards to the hierarcy.
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* We need to do this because the xHCI driver might not yet be
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* bound so the USB3 SuperSpeed ports are not yet created.
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*/
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dev = acpi_get_first_physical_node(adev);
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while (!dev) {
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adev = adev->parent;
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if (!adev)
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break;
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dev = acpi_get_first_physical_node(adev);
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}
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if (!dev)
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goto out_put;
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/*
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* Check that the device is PCIe. This is because USB3
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* SuperSpeed ports have this property and they are not power
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* managed with the xHCI and the SuperSpeed hub so we create the
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* link from xHCI instead.
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*/
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while (dev && !dev_is_pci(dev))
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dev = dev->parent;
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if (!dev)
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goto out_put;
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/*
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* Check that this actually matches the type of device we
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* expect. It should either be xHCI or PCIe root/downstream
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* port.
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*/
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pdev = to_pci_dev(dev);
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if (pdev->class == PCI_CLASS_SERIAL_USB_XHCI ||
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(pci_is_pcie(pdev) &&
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(pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
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pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM))) {
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const struct device_link *link;
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link = device_link_add(&pdev->dev, &nhi->pdev->dev,
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DL_FLAG_AUTOREMOVE_SUPPLIER |
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DL_FLAG_PM_RUNTIME);
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if (link) {
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dev_dbg(&nhi->pdev->dev, "created link from %s\n",
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dev_name(&pdev->dev));
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} else {
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dev_warn(&nhi->pdev->dev, "device link creation from %s failed\n",
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dev_name(&pdev->dev));
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}
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}
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out_put:
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fwnode_handle_put(args.fwnode);
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return AE_OK;
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}
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/**
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* tb_acpi_add_links() - Add device links based on ACPI description
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* @nhi: Pointer to NHI
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*
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* Goes over ACPI namespace finding tunneled ports that reference to
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* @nhi ACPI node. For each reference a device link is added. The link
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* is automatically removed by the driver core.
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*/
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void tb_acpi_add_links(struct tb_nhi *nhi)
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{
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acpi_status status;
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if (!has_acpi_companion(&nhi->pdev->dev))
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return;
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/*
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* Find all devices that have usb4-host-controller interface
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* property that references to this NHI.
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*/
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status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
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tb_acpi_add_link, NULL, nhi, NULL);
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if (ACPI_FAILURE(status))
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dev_warn(&nhi->pdev->dev, "failed to enumerate tunneled ports\n");
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}
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