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/nvmem/apple-efuses.c | 81 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 drivers/nvmem/apple-efuses.c (limited to 'drivers/nvmem/apple-efuses.c') diff --git a/drivers/nvmem/apple-efuses.c b/drivers/nvmem/apple-efuses.c new file mode 100644 index 000000000..9913e77b8 --- /dev/null +++ b/drivers/nvmem/apple-efuses.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Apple SoC eFuse driver + * + * Copyright (C) The Asahi Linux Contributors + */ + +#include +#include +#include +#include + +struct apple_efuses_priv { + void __iomem *fuses; +}; + +static int apple_efuses_read(void *context, unsigned int offset, void *val, + size_t bytes) +{ + struct apple_efuses_priv *priv = context; + u32 *dst = val; + + while (bytes >= sizeof(u32)) { + *dst++ = readl_relaxed(priv->fuses + offset); + bytes -= sizeof(u32); + offset += sizeof(u32); + } + + return 0; +} + +static int apple_efuses_probe(struct platform_device *pdev) +{ + struct apple_efuses_priv *priv; + struct resource *res; + struct nvmem_config config = { + .dev = &pdev->dev, + .add_legacy_fixed_of_cells = true, + .read_only = true, + .reg_read = apple_efuses_read, + .stride = sizeof(u32), + .word_size = sizeof(u32), + .name = "apple_efuses_nvmem", + .id = NVMEM_DEVID_AUTO, + .root_only = true, + }; + + priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(priv->fuses)) + return PTR_ERR(priv->fuses); + + config.priv = priv; + config.size = resource_size(res); + + return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config)); +} + +static const struct of_device_id apple_efuses_of_match[] = { + { .compatible = "apple,efuses", }, + {} +}; + +MODULE_DEVICE_TABLE(of, apple_efuses_of_match); + +static struct platform_driver apple_efuses_driver = { + .driver = { + .name = "apple_efuses", + .of_match_table = apple_efuses_of_match, + }, + .probe = apple_efuses_probe, +}; + +module_platform_driver(apple_efuses_driver); + +MODULE_AUTHOR("Sven Peter "); +MODULE_DESCRIPTION("Apple SoC eFuse driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1