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, 63 insertions, 0 deletions

diff --git a/include/video/sa1100fb.h b/include/video/sa1100fb.h
new file mode 100644
index 000000000..4ab409653
--- /dev/null
+++ b/include/video/sa1100fb.h
@@ -0,0 +1,63 @@
+/*
+ * StrongARM 1100 LCD Controller Frame Buffer Device
+ *
+ * Copyright (C) 1999 Eric A. Thomas
+ *  Based on acornfb.c Copyright (C) Russell King.
+ *  
+ * 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.
+ */
+#ifndef _VIDEO_SA1100FB_H
+#define _VIDEO_SA1100FB_H
+
+#include <linux/fb.h>
+#include <linux/types.h>
+
+#define RGB_4	0
+#define RGB_8	1
+#define RGB_16	2
+#define NR_RGB	3
+
+/* These are the bitfields for each display depth that we support. */
+struct sa1100fb_rgb {
+	struct fb_bitfield	red;
+	struct fb_bitfield	green;
+	struct fb_bitfield	blue;
+	struct fb_bitfield	transp;
+};
+
+/* This structure describes the machine which we are running on. */
+struct sa1100fb_mach_info {
+	u_long		pixclock;
+
+	u_short		xres;
+	u_short		yres;
+
+	u_char		bpp;
+	u_char		hsync_len;
+	u_char		left_margin;
+	u_char		right_margin;
+
+	u_char		vsync_len;
+	u_char		upper_margin;
+	u_char		lower_margin;
+	u_char		sync;
+
+	u_int		cmap_greyscale:1,
+			cmap_inverse:1,
+			cmap_static:1,
+			unused:29;
+
+	u_int		lccr0;
+	u_int		lccr3;
+
+	/* Overrides for the default RGB maps */
+	const struct sa1100fb_rgb *rgb[NR_RGB];
+
+	void (*backlight_power)(int);
+	void (*lcd_power)(int);
+	void (*set_visual)(u32);
+};
+
+#endif