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, 47 insertions, 0 deletions

diff --git a/drivers/md/bcache/request.h b/drivers/md/bcache/request.h
new file mode 100644
index 000000000..46bbef00a
--- /dev/null
+++ b/drivers/md/bcache/request.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHE_REQUEST_H_
+#define _BCACHE_REQUEST_H_
+
+struct data_insert_op {
+	struct closure		cl;
+	struct cache_set	*c;
+	struct bio		*bio;
+	struct workqueue_struct *wq;
+
+	unsigned int		inode;
+	uint16_t		write_point;
+	uint16_t		write_prio;
+	blk_status_t		status;
+
+	union {
+		uint16_t	flags;
+
+	struct {
+		unsigned int	bypass:1;
+		unsigned int	writeback:1;
+		unsigned int	flush_journal:1;
+		unsigned int	csum:1;
+
+		unsigned int	replace:1;
+		unsigned int	replace_collision:1;
+
+		unsigned int	insert_data_done:1;
+	};
+	};
+
+	struct keylist		insert_keys;
+	BKEY_PADDED(replace_key);
+};
+
+unsigned int bch_get_congested(const struct cache_set *c);
+CLOSURE_CALLBACK(bch_data_insert);
+
+void bch_cached_dev_request_init(struct cached_dev *dc);
+void cached_dev_submit_bio(struct bio *bio);
+
+void bch_flash_dev_request_init(struct bcache_device *d);
+void flash_dev_submit_bio(struct bio *bio);
+
+extern struct kmem_cache *bch_search_cache;
+
+#endif /* _BCACHE_REQUEST_H_ */