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, 123 insertions, 0 deletions

diff --git a/include/uapi/rdma/mana-abi.h b/include/uapi/rdma/mana-abi.h
new file mode 100644
index 000000000..32cbbfc80
--- /dev/null
+++ b/include/uapi/rdma/mana-abi.h
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) */
+/*
+ * Copyright (c) 2022, Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef MANA_ABI_USER_H
+#define MANA_ABI_USER_H
+
+#include <linux/types.h>
+#include <rdma/ib_user_ioctl_verbs.h>
+
+/*
+ * Increment this value if any changes that break userspace ABI
+ * compatibility are made.
+ */
+
+#define MANA_IB_UVERBS_ABI_VERSION 1
+
+enum mana_ib_create_cq_flags {
+	/* Reserved for backward compatibility. Legacy
+	 * kernel versions use it to create CQs in RNIC
+	 */
+	MANA_IB_CREATE_RNIC_CQ	= 1 << 0,
+};
+
+struct mana_ib_create_cq {
+	__aligned_u64 buf_addr;
+	__u16	comp_mask;
+	__u16	reserved0;
+	__u32	reserved1;
+};
+
+struct mana_ib_create_cq_resp {
+	__u32 cqid;
+	__u32 reserved;
+};
+
+struct mana_ib_create_qp {
+	__aligned_u64 sq_buf_addr;
+	__u32 sq_buf_size;
+	__u32 port;
+};
+
+struct mana_ib_create_qp_resp {
+	__u32 sqid;
+	__u32 cqid;
+	__u32 tx_vp_offset;
+	__u32 reserved;
+};
+
+struct mana_ib_create_rc_qp {
+	__aligned_u64 queue_buf[4];
+	__u32 queue_size[4];
+};
+
+struct mana_ib_create_rc_qp_resp {
+	__u32 queue_id[4];
+};
+
+struct mana_ib_create_uc_qp {
+	__aligned_u64 queue_buf[3];
+	__u32 queue_size[3];
+	__u32 comp_mask;
+};
+
+struct mana_ib_create_uc_qp_resp {
+	__u32 queue_id[3];
+	__u32 reserved;
+};
+
+struct mana_ib_create_wq {
+	__aligned_u64 wq_buf_addr;
+	__u32 wq_buf_size;
+	__u32 reserved;
+};
+
+/* RX Hash function flags */
+enum mana_ib_rx_hash_function_flags {
+	MANA_IB_RX_HASH_FUNC_TOEPLITZ = 1 << 0,
+};
+
+struct mana_ib_create_qp_rss {
+	__aligned_u64 rx_hash_fields_mask;
+	__u8 rx_hash_function;
+	__u8 reserved[7];
+	__u32 rx_hash_key_len;
+	__u8 rx_hash_key[40];
+	__u32 port;
+};
+
+struct rss_resp_entry {
+	__u32 cqid;
+	__u32 wqid;
+};
+
+struct mana_ib_create_qp_rss_resp {
+	__aligned_u64 num_entries;
+	struct rss_resp_entry entries[64];
+};
+
+enum mana_ib_ucontext_support {
+	MANA_IB_UCNTX_ALLOC_PDN_SUPPORT = 1 << 0,
+};
+
+struct mana_ib_alloc_ucontext_resp {
+	__aligned_u64 comp_mask;
+};
+
+enum mana_ib_create_pd_flags {
+	MANA_IB_PD_SHORT_PDN = 1 << 0,
+};
+
+struct mana_ib_alloc_pd {
+	__u32 comp_mask;
+	__u32 reserved;
+};
+
+struct mana_ib_alloc_pd_resp {
+	__u32 pdn;
+	__u32 reserved;
+};
+
+#endif