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, 19 insertions, 0 deletions

diff --git a/drivers/video/fbdev/c2p.h b/drivers/video/fbdev/c2p.h
new file mode 100644
index 000000000..6c38d4042
--- /dev/null
+++ b/drivers/video/fbdev/c2p.h
@@ -0,0 +1,19 @@
+/*
+ *  Fast C2P (Chunky-to-Planar) Conversion
+ *
+ *  Copyright (C) 2003-2008 Geert Uytterhoeven
+ *
+ *  This file is subject to the terms and conditions of the GNU General Public
+ *  License. See the file COPYING in the main directory of this archive
+ *  for more details.
+ */
+
+#include <linux/types.h>
+
+extern void c2p_planar(void *dst, const void *src, u32 dx, u32 dy, u32 width,
+		       u32 height, u32 dst_nextline, u32 dst_nextplane,
+		       u32 src_nextline, u32 bpp);
+
+extern void c2p_iplan2(void *dst, const void *src, u32 dx, u32 dy, u32 width,
+		       u32 height, u32 dst_nextline, u32 src_nextline,
+		       u32 bpp);