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, 66 insertions, 0 deletions

diff --git a/include/sound/mixer_oss.h b/include/sound/mixer_oss.h
new file mode 100644
index 000000000..9a212c0ce
--- /dev/null
+++ b/include/sound/mixer_oss.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __SOUND_MIXER_OSS_H
+#define __SOUND_MIXER_OSS_H
+
+/*
+ *  OSS MIXER API
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#if IS_ENABLED(CONFIG_SND_MIXER_OSS)
+
+#define SNDRV_OSS_MAX_MIXERS	32
+
+struct snd_mixer_oss_file;
+
+struct snd_mixer_oss_slot {
+	int number;
+	unsigned int stereo: 1;
+	int (*get_volume)(struct snd_mixer_oss_file *fmixer,
+			  struct snd_mixer_oss_slot *chn,
+			  int *left, int *right);
+	int (*put_volume)(struct snd_mixer_oss_file *fmixer,
+			  struct snd_mixer_oss_slot *chn,
+			  int left, int right);
+	int (*get_recsrc)(struct snd_mixer_oss_file *fmixer,
+			  struct snd_mixer_oss_slot *chn,
+			  int *active);
+	int (*put_recsrc)(struct snd_mixer_oss_file *fmixer,
+			  struct snd_mixer_oss_slot *chn,
+			  int active);
+	unsigned long private_value;
+	void *private_data;
+	void (*private_free)(struct snd_mixer_oss_slot *slot);
+	int volume[2];
+};
+
+struct snd_mixer_oss {
+	struct snd_card *card;
+	char id[16];
+	char name[32];
+	struct snd_mixer_oss_slot slots[SNDRV_OSS_MAX_MIXERS]; /* OSS mixer slots */
+	unsigned int mask_recsrc;		/* exclusive recsrc mask */
+	int (*get_recsrc)(struct snd_mixer_oss_file *fmixer,
+			  unsigned int *active_index);
+	int (*put_recsrc)(struct snd_mixer_oss_file *fmixer,
+			  unsigned int active_index);
+	void *private_data_recsrc;
+	void (*private_free_recsrc)(struct snd_mixer_oss *mixer);
+	struct mutex reg_mutex;
+	struct snd_info_entry *proc_entry;
+	int oss_dev_alloc;
+	/* --- */
+	int oss_recsrc;
+};
+
+struct snd_mixer_oss_file {
+	struct snd_card *card;
+	struct snd_mixer_oss *mixer;
+};
+
+int snd_mixer_oss_ioctl_card(struct snd_card *card,
+			     unsigned int cmd, unsigned long arg);
+
+#endif /* CONFIG_SND_MIXER_OSS */
+
+#endif /* __SOUND_MIXER_OSS_H */