x86/amd_node: Fix PCI device reference counting in amd_smn_init()grafted

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 <sashiko-bot@kernel.org>
Assisted-by: LLM
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com

1 files changed, 49 insertions, 0 deletions

diff --git a/include/uapi/rdma/erdma-abi.h b/include/uapi/rdma/erdma-abi.h
new file mode 100644
index 000000000..b7a0222f9
--- /dev/null
+++ b/include/uapi/rdma/erdma-abi.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/*
+ * Copyright (c) 2020-2022, Alibaba Group.
+ */
+
+#ifndef __ERDMA_USER_H__
+#define __ERDMA_USER_H__
+
+#include <linux/types.h>
+
+#define ERDMA_ABI_VERSION       1
+
+struct erdma_ureq_create_cq {
+	__aligned_u64 db_record_va;
+	__aligned_u64 qbuf_va;
+	__u32 qbuf_len;
+	__u32 rsvd0;
+};
+
+struct erdma_uresp_create_cq {
+	__u32 cq_id;
+	__u32 num_cqe;
+};
+
+struct erdma_ureq_create_qp {
+	__aligned_u64 db_record_va;
+	__aligned_u64 qbuf_va;
+	__u32 qbuf_len;
+	__u32 rsvd0;
+};
+
+struct erdma_uresp_create_qp {
+	__u32 qp_id;
+	__u32 num_sqe;
+	__u32 num_rqe;
+	__u32 rq_offset;
+};
+
+struct erdma_uresp_alloc_ctx {
+	__u32 dev_id;
+	__u32 pad;
+	__u32 sdb_type;
+	__u32 sdb_offset;
+	__aligned_u64 sdb;
+	__aligned_u64 rdb;
+	__aligned_u64 cdb;
+};
+
+#endif