From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/gpu/host1x/mipi.c | 195 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 drivers/gpu/host1x/mipi.c (limited to 'drivers/gpu/host1x/mipi.c') diff --git a/drivers/gpu/host1x/mipi.c b/drivers/gpu/host1x/mipi.c new file mode 100644 index 000000000..988681423 --- /dev/null +++ b/drivers/gpu/host1x/mipi.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2013 NVIDIA Corporation + * Copyright (C) 2025 Svyatoslav Ryhel + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* only need to support one provider */ +static struct { + struct device_node *np; + const struct tegra_mipi_ops *ops; +} provider; + +/** + * tegra_mipi_enable - Enable the Tegra MIPI calibration device. + * @device: Handle to the Tegra MIPI calibration device. + * + * This calls the enable sequence for the Tegra MIPI calibration device. + * + * Returns 0 on success or a negative error code on failure. + */ +int tegra_mipi_enable(struct tegra_mipi_device *device) +{ + if (device->ops->enable) + return device->ops->enable(device); + + return 0; +} +EXPORT_SYMBOL(tegra_mipi_enable); + +/** + * tegra_mipi_disable - Disable the Tegra MIPI calibration device. + * @device: Handle to the Tegra MIPI calibration device. + * + * This calls the disable sequence for the Tegra MIPI calibration device. + * + * Returns 0 on success or a negative error code on failure. + */ +int tegra_mipi_disable(struct tegra_mipi_device *device) +{ + if (device->ops->disable) + return device->ops->disable(device); + + return 0; +} +EXPORT_SYMBOL(tegra_mipi_disable); + +/** + * tegra_mipi_start_calibration - Start the Tegra MIPI calibration sequence. + * @device: Handle to the Tegra MIPI calibration device. + * + * This initiates the calibration of CSI/DSI interfaces via the Tegra MIPI + * calibration device. + * + * Returns 0 on success or a negative error code on failure. + */ +int tegra_mipi_start_calibration(struct tegra_mipi_device *device) +{ + if (device->ops->start_calibration) + return device->ops->start_calibration(device); + + return 0; +} +EXPORT_SYMBOL(tegra_mipi_start_calibration); + +/** + * tegra_mipi_finish_calibration - Finish the Tegra MIPI calibration sequence. + * @device: Handle to the Tegra MIPI calibration device. + * + * This completes the calibration of CSI/DSI interfaces via the Tegra MIPI + * calibration device. + * + * Returns 0 on success or a negative error code on failure. + */ +int tegra_mipi_finish_calibration(struct tegra_mipi_device *device) +{ + if (device->ops->finish_calibration) + return device->ops->finish_calibration(device); + + return 0; +} +EXPORT_SYMBOL(tegra_mipi_finish_calibration); + +/** + * tegra_mipi_request - Request a Tegra MIPI calibration device. + * @device: Handle of the device requesting the MIPI calibration function. + * @np: Device node pointer of the device requesting the MIPI calibration + * function. + * + * This function requests a reference to a Tegra MIPI calibration device. + * + * Returns a pointer to the Tegra MIPI calibration device on success, + * or an ERR_PTR-encoded error code on failure. + */ +struct tegra_mipi_device *tegra_mipi_request(struct device *device, + struct device_node *np) +{ + struct tegra_mipi_device *mipidev; + struct of_phandle_args args; + int err; + + err = of_parse_phandle_with_args(np, "nvidia,mipi-calibrate", + "#nvidia,mipi-calibrate-cells", 0, + &args); + if (err < 0) + return ERR_PTR(err); + + if (provider.np != args.np) { + err = -ENODEV; + goto out; + } + + mipidev = kzalloc_obj(*mipidev); + if (!mipidev) { + err = -ENOMEM; + goto out; + } + + mipidev->pdev = of_find_device_by_node(args.np); + if (!mipidev->pdev) { + err = -ENODEV; + goto free; + } + + of_node_put(args.np); + + mipidev->ops = provider.ops; + mipidev->pads = args.args[0]; + + return mipidev; + +free: + kfree(mipidev); +out: + of_node_put(args.np); + return ERR_PTR(err); +} +EXPORT_SYMBOL(tegra_mipi_request); + +/** + * tegra_mipi_free - Free a Tegra MIPI calibration device. + * @mipidev: Handle to the Tegra MIPI calibration device. + * + * This function releases a reference to a Tegra MIPI calibration device + * previously requested by tegra_mipi_request(). + */ +void tegra_mipi_free(struct tegra_mipi_device *mipidev) +{ + platform_device_put(mipidev->pdev); + kfree(mipidev); +} +EXPORT_SYMBOL(tegra_mipi_free); + +static void tegra_mipi_remove_provider(void *data) +{ + provider.np = NULL; + provider.ops = NULL; +} + +/** + * devm_tegra_mipi_add_provider - Managed registration of a Tegra MIPI + * calibration function provider. + * @device: Handle to the device providing the MIPI calibration function. + * @np: Device node pointer of the device providing the MIPI calibration + * function. + * @ops: Operations supported by the MIPI calibration device. + * + * This registers a device that provides MIPI calibration functions. + * For Tegra20 and Tegra30, this is the CSI block, while Tegra114 and + * newer SoC generations have a dedicated hardware block for these + * functions. + * + * Returns 0 on success or a negative error code on failure. + */ +int devm_tegra_mipi_add_provider(struct device *device, struct device_node *np, + const struct tegra_mipi_ops *ops) +{ + if (provider.np) + return -EBUSY; + + provider.np = np; + provider.ops = ops; + + return devm_add_action_or_reset(device, tegra_mipi_remove_provider, NULL); +} +EXPORT_SYMBOL(devm_tegra_mipi_add_provider); -- cgit v1.3.1