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/drm/drm_blend.h b/include/drm/drm_blend.h
new file mode 100644
index 000000000..bebbb77a8
--- /dev/null
+++ b/include/drm/drm_blend.h
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2016 Intel Corporation
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+
+#ifndef __DRM_BLEND_H__
+#define __DRM_BLEND_H__
+
+#include <linux/list.h>
+#include <linux/ctype.h>
+#include <drm/drm_mode.h>
+
+#define DRM_MODE_BLEND_PREMULTI		0
+#define DRM_MODE_BLEND_COVERAGE		1
+#define DRM_MODE_BLEND_PIXEL_NONE	2
+
+struct drm_atomic_commit;
+struct drm_crtc;
+struct drm_device;
+struct drm_plane;
+
+static inline bool drm_rotation_90_or_270(unsigned int rotation)
+{
+	return rotation & (DRM_MODE_ROTATE_90 | DRM_MODE_ROTATE_270);
+}
+
+#define DRM_BLEND_ALPHA_OPAQUE		0xffff
+
+int drm_plane_create_alpha_property(struct drm_plane *plane);
+int drm_plane_create_rotation_property(struct drm_plane *plane,
+				       unsigned int rotation,
+				       unsigned int supported_rotations);
+unsigned int drm_rotation_simplify(unsigned int rotation,
+				   unsigned int supported_rotations);
+
+int drm_plane_create_zpos_property(struct drm_plane *plane,
+				   unsigned int zpos,
+				   unsigned int min, unsigned int max);
+int drm_plane_create_zpos_immutable_property(struct drm_plane *plane,
+					     unsigned int zpos);
+int drm_atomic_normalize_zpos(struct drm_device *dev,
+			      struct drm_atomic_commit *state);
+int drm_plane_create_blend_mode_property(struct drm_plane *plane,
+					 unsigned int supported_modes);
+void drm_crtc_attach_background_color_property(struct drm_crtc *crtc);
+#endif