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 --- include/asm-generic/atomic64.h | 75 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 include/asm-generic/atomic64.h (limited to 'include/asm-generic/atomic64.h') diff --git a/include/asm-generic/atomic64.h b/include/asm-generic/atomic64.h new file mode 100644 index 000000000..f22ccfc0d --- /dev/null +++ b/include/asm-generic/atomic64.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Generic implementation of 64-bit atomics using spinlocks, + * useful on processors that don't have 64-bit atomic instructions. + * + * Copyright © 2009 Paul Mackerras, IBM Corp. + */ +#ifndef _ASM_GENERIC_ATOMIC64_H +#define _ASM_GENERIC_ATOMIC64_H +#include + +typedef struct { + s64 __aligned(sizeof(s64)) counter; +} atomic64_t; + +#define ATOMIC64_INIT(i) { (i) } + +extern s64 generic_atomic64_read(const atomic64_t *v); +extern void generic_atomic64_set(atomic64_t *v, s64 i); + +#define ATOMIC64_OP(op) \ +extern void generic_atomic64_##op(s64 a, atomic64_t *v); + +#define ATOMIC64_OP_RETURN(op) \ +extern s64 generic_atomic64_##op##_return(s64 a, atomic64_t *v); + +#define ATOMIC64_FETCH_OP(op) \ +extern s64 generic_atomic64_fetch_##op(s64 a, atomic64_t *v); + +#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_OP_RETURN(op) ATOMIC64_FETCH_OP(op) + +ATOMIC64_OPS(add) +ATOMIC64_OPS(sub) + +#undef ATOMIC64_OPS +#define ATOMIC64_OPS(op) ATOMIC64_OP(op) ATOMIC64_FETCH_OP(op) + +ATOMIC64_OPS(and) +ATOMIC64_OPS(or) +ATOMIC64_OPS(xor) + +#undef ATOMIC64_OPS +#undef ATOMIC64_FETCH_OP +#undef ATOMIC64_OP_RETURN +#undef ATOMIC64_OP + +extern s64 generic_atomic64_dec_if_positive(atomic64_t *v); +extern s64 generic_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n); +extern s64 generic_atomic64_xchg(atomic64_t *v, s64 new); +extern s64 generic_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u); + +#define arch_atomic64_read generic_atomic64_read +#define arch_atomic64_set generic_atomic64_set +#define arch_atomic64_set_release generic_atomic64_set + +#define arch_atomic64_add generic_atomic64_add +#define arch_atomic64_add_return generic_atomic64_add_return +#define arch_atomic64_fetch_add generic_atomic64_fetch_add +#define arch_atomic64_sub generic_atomic64_sub +#define arch_atomic64_sub_return generic_atomic64_sub_return +#define arch_atomic64_fetch_sub generic_atomic64_fetch_sub + +#define arch_atomic64_and generic_atomic64_and +#define arch_atomic64_fetch_and generic_atomic64_fetch_and +#define arch_atomic64_or generic_atomic64_or +#define arch_atomic64_fetch_or generic_atomic64_fetch_or +#define arch_atomic64_xor generic_atomic64_xor +#define arch_atomic64_fetch_xor generic_atomic64_fetch_xor + +#define arch_atomic64_dec_if_positive generic_atomic64_dec_if_positive +#define arch_atomic64_cmpxchg generic_atomic64_cmpxchg +#define arch_atomic64_xchg generic_atomic64_xchg +#define arch_atomic64_fetch_add_unless generic_atomic64_fetch_add_unless + +#endif /* _ASM_GENERIC_ATOMIC64_H */ -- cgit v1.3.1