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/net/hwbm.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 include/net/hwbm.h (limited to 'include/net/hwbm.h') diff --git a/include/net/hwbm.h b/include/net/hwbm.h new file mode 100644 index 000000000..bdbe91c60 --- /dev/null +++ b/include/net/hwbm.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _HWBM_H +#define _HWBM_H + +#include + +struct hwbm_pool { + /* Capacity of the pool */ + int size; + /* Size of the buffers managed */ + int frag_size; + /* Number of buffers currently used by this pool */ + int buf_num; + /* constructor called during allocation */ + int (*construct)(struct hwbm_pool *bm_pool, void *buf); + /* protect access to the buffer counter*/ + struct mutex buf_lock; + /* private data */ + void *priv; +}; +#ifdef CONFIG_HWBM +void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf); +int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp); +int hwbm_pool_add(struct hwbm_pool *bm_pool, unsigned int buf_num); +#else +static inline void hwbm_buf_free(struct hwbm_pool *bm_pool, void *buf) {} + +static inline int hwbm_pool_refill(struct hwbm_pool *bm_pool, gfp_t gfp) +{ return 0; } + +static inline int hwbm_pool_add(struct hwbm_pool *bm_pool, + unsigned int buf_num) +{ return 0; } +#endif /* CONFIG_HWBM */ +#endif /* _HWBM_H */ -- cgit v1.3.1