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/iomem_copy.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 lib/iomem_copy.c (limited to 'lib/iomem_copy.c') diff --git a/lib/iomem_copy.c b/lib/iomem_copy.c new file mode 100644 index 000000000..dec7eaea6 --- /dev/null +++ b/lib/iomem_copy.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2024 Kalray, Inc. All Rights Reserved. + */ + +#include +#include +#include +#include +#include + +#ifndef memset_io +/** + * memset_io() - Set a range of I/O memory to a constant value + * @addr: The beginning of the I/O-memory range to set + * @val: The value to set the memory to + * @count: The number of bytes to set + * + * Set a range of I/O memory to a given value. + */ +void memset_io(volatile void __iomem *addr, int val, size_t count) +{ + long qc = (u8)val; + + qc *= ~0UL / 0xff; + + while (count && !IS_ALIGNED((long)addr, sizeof(long))) { + __raw_writeb(val, addr); + addr++; + count--; + } + + while (count >= sizeof(long)) { +#ifdef CONFIG_64BIT + __raw_writeq(qc, addr); +#else + __raw_writel(qc, addr); +#endif + + addr += sizeof(long); + count -= sizeof(long); + } + + while (count) { + __raw_writeb(val, addr); + addr++; + count--; + } +} +EXPORT_SYMBOL(memset_io); +#endif + +#ifndef memcpy_fromio +/** + * memcpy_fromio() - Copy a block of data from I/O memory + * @dst: The (RAM) destination for the copy + * @src: The (I/O memory) source for the data + * @count: The number of bytes to copy + * + * Copy a block of data from I/O memory. + */ +void memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count) +{ + while (count && !IS_ALIGNED((long)src, sizeof(long))) { + *(u8 *)dst = __raw_readb(src); + src++; + dst++; + count--; + } + + while (count >= sizeof(long)) { +#ifdef CONFIG_64BIT + long val = __raw_readq(src); +#else + long val = __raw_readl(src); +#endif + put_unaligned(val, (long *)dst); + + + src += sizeof(long); + dst += sizeof(long); + count -= sizeof(long); + } + + while (count) { + *(u8 *)dst = __raw_readb(src); + src++; + dst++; + count--; + } +} +EXPORT_SYMBOL(memcpy_fromio); +#endif + +#ifndef memcpy_toio +/** + * memcpy_toio() -Copy a block of data into I/O memory + * @dst: The (I/O memory) destination for the copy + * @src: The (RAM) source for the data + * @count: The number of bytes to copy + * + * Copy a block of data to I/O memory. + */ +void memcpy_toio(volatile void __iomem *dst, const void *src, size_t count) +{ + while (count && !IS_ALIGNED((long)dst, sizeof(long))) { + __raw_writeb(*(u8 *)src, dst); + src++; + dst++; + count--; + } + + while (count >= sizeof(long)) { + long val = get_unaligned((long *)src); +#ifdef CONFIG_64BIT + __raw_writeq(val, dst); +#else + __raw_writel(val, dst); +#endif + + src += sizeof(long); + dst += sizeof(long); + count -= sizeof(long); + } + + while (count) { + __raw_writeb(*(u8 *)src, dst); + src++; + dst++; + count--; + } +} +EXPORT_SYMBOL(memcpy_toio); +#endif + + -- cgit v1.3.1