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/power/reset/syscon-reboot-mode.c | 86 ++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 drivers/power/reset/syscon-reboot-mode.c (limited to 'drivers/power/reset/syscon-reboot-mode.c') diff --git a/drivers/power/reset/syscon-reboot-mode.c b/drivers/power/reset/syscon-reboot-mode.c new file mode 100644 index 000000000..e0772c9f7 --- /dev/null +++ b/drivers/power/reset/syscon-reboot-mode.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct syscon_reboot_mode { + struct regmap *map; + struct reboot_mode_driver reboot; + u32 offset; + u32 mask; +}; + +static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot, + unsigned int magic) +{ + struct syscon_reboot_mode *syscon_rbm; + int ret; + + syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot); + + ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset, + syscon_rbm->mask, magic); + if (ret < 0) + dev_err(reboot->dev, "update reboot mode bits failed\n"); + + return ret; +} + +static int syscon_reboot_mode_probe(struct platform_device *pdev) +{ + int ret; + struct syscon_reboot_mode *syscon_rbm; + + syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL); + if (!syscon_rbm) + return -ENOMEM; + + syscon_rbm->reboot.dev = &pdev->dev; + syscon_rbm->reboot.write = syscon_reboot_mode_write; + syscon_rbm->mask = 0xffffffff; + + syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node); + if (IS_ERR(syscon_rbm->map)) + return PTR_ERR(syscon_rbm->map); + + if (of_property_read_u32(pdev->dev.of_node, "offset", + &syscon_rbm->offset)) + return -EINVAL; + + of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask); + + ret = devm_reboot_mode_register(&pdev->dev, &syscon_rbm->reboot); + if (ret) + dev_err(&pdev->dev, "can't register reboot mode\n"); + + return ret; +} + +static const struct of_device_id syscon_reboot_mode_of_match[] = { + { .compatible = "syscon-reboot-mode" }, + {} +}; +MODULE_DEVICE_TABLE(of, syscon_reboot_mode_of_match); + +static struct platform_driver syscon_reboot_mode_driver = { + .probe = syscon_reboot_mode_probe, + .driver = { + .name = "syscon-reboot-mode", + .of_match_table = syscon_reboot_mode_of_match, + }, +}; +module_platform_driver(syscon_reboot_mode_driver); + +MODULE_AUTHOR("Andy Yan