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 --- lib/iomap_copy.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 lib/iomap_copy.c (limited to 'lib/iomap_copy.c') diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c new file mode 100644 index 000000000..2fd5712fb --- /dev/null +++ b/lib/iomap_copy.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2006 PathScale, Inc. All Rights Reserved. + */ + +#include +#include + +/** + * __iowrite32_copy - copy data to MMIO space, in 32-bit units + * @to: destination, in MMIO space (must be 32-bit aligned) + * @from: source (must be 32-bit aligned) + * @count: number of 32-bit quantities to copy + * + * Copy data from kernel space to MMIO space, in units of 32 bits at a + * time. Order of access is not guaranteed, nor is a memory barrier + * performed afterwards. + */ +#ifndef __iowrite32_copy +void __iowrite32_copy(void __iomem *to, const void *from, size_t count) +{ + u32 __iomem *dst = to; + const u32 *src = from; + const u32 *end = src + count; + + while (src < end) + __raw_writel(*src++, dst++); +} +EXPORT_SYMBOL_GPL(__iowrite32_copy); +#endif + +/** + * __ioread32_copy - copy data from MMIO space, in 32-bit units + * @to: destination (must be 32-bit aligned) + * @from: source, in MMIO space (must be 32-bit aligned) + * @count: number of 32-bit quantities to copy + * + * Copy data from MMIO space to kernel space, in units of 32 bits at a + * time. Order of access is not guaranteed, nor is a memory barrier + * performed afterwards. + */ +void __ioread32_copy(void *to, const void __iomem *from, size_t count) +{ + u32 *dst = to; + const u32 __iomem *src = from; + const u32 __iomem *end = src + count; + + while (src < end) + *dst++ = __raw_readl(src++); +} +EXPORT_SYMBOL_GPL(__ioread32_copy); + +/** + * __iowrite64_copy - copy data to MMIO space, in 64-bit or 32-bit units + * @to: destination, in MMIO space (must be 64-bit aligned) + * @from: source (must be 64-bit aligned) + * @count: number of 64-bit quantities to copy + * + * Copy data from kernel space to MMIO space, in units of 32 or 64 bits at a + * time. Order of access is not guaranteed, nor is a memory barrier + * performed afterwards. + */ +#ifndef __iowrite64_copy +void __iowrite64_copy(void __iomem *to, const void *from, size_t count) +{ +#ifdef CONFIG_64BIT + u64 __iomem *dst = to; + const u64 *src = from; + const u64 *end = src + count; + + while (src < end) + __raw_writeq(*src++, dst++); +#else + __iowrite32_copy(to, from, count * 2); +#endif +} +EXPORT_SYMBOL_GPL(__iowrite64_copy); +#endif -- cgit v1.3.1