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, 97 insertions, 0 deletions

diff --git a/include/sound/minors.h b/include/sound/minors.h
new file mode 100644
index 000000000..2b0395693
--- /dev/null
+++ b/include/sound/minors.h
@@ -0,0 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __SOUND_MINORS_H
+#define __SOUND_MINORS_H
+
+/*
+ *  MINOR numbers
+ */
+
+#define SNDRV_OS_MINORS			256
+
+#define SNDRV_MINOR_DEVICES		32
+#define SNDRV_MINOR_CARD(minor)		((minor) >> 5)
+#define SNDRV_MINOR_DEVICE(minor)	((minor) & 0x001f)
+#define SNDRV_MINOR(card, dev)		(((card) << 5) | (dev))
+
+/* these minors can still be used for autoloading devices (/dev/aload*) */
+#define SNDRV_MINOR_CONTROL		0	/* 0 */
+#define SNDRV_MINOR_GLOBAL		1	/* 1 */
+#define SNDRV_MINOR_SEQUENCER		1	/* SNDRV_MINOR_GLOBAL + 0 * 32 */
+#define SNDRV_MINOR_TIMER		33	/* SNDRV_MINOR_GLOBAL + 1 * 32 */
+
+#ifndef CONFIG_SND_DYNAMIC_MINORS
+#define SNDRV_MINOR_COMPRESS		2	/* 2 - 3 */
+#define SNDRV_MINOR_HWDEP		4	/* 4 - 7 */
+#define SNDRV_MINOR_RAWMIDI		8	/* 8 - 15 */
+#define SNDRV_MINOR_PCM_PLAYBACK	16	/* 16 - 23 */
+#define SNDRV_MINOR_PCM_CAPTURE		24	/* 24 - 31 */
+
+/* same as first respective minor number to make minor allocation easier */
+#define SNDRV_DEVICE_TYPE_CONTROL	SNDRV_MINOR_CONTROL
+#define SNDRV_DEVICE_TYPE_HWDEP		SNDRV_MINOR_HWDEP
+#define SNDRV_DEVICE_TYPE_RAWMIDI	SNDRV_MINOR_RAWMIDI
+#define SNDRV_DEVICE_TYPE_PCM_PLAYBACK	SNDRV_MINOR_PCM_PLAYBACK
+#define SNDRV_DEVICE_TYPE_PCM_CAPTURE	SNDRV_MINOR_PCM_CAPTURE
+#define SNDRV_DEVICE_TYPE_SEQUENCER	SNDRV_MINOR_SEQUENCER
+#define SNDRV_DEVICE_TYPE_TIMER		SNDRV_MINOR_TIMER
+#define SNDRV_DEVICE_TYPE_COMPRESS	SNDRV_MINOR_COMPRESS
+
+#else /* CONFIG_SND_DYNAMIC_MINORS */
+
+enum {
+	SNDRV_DEVICE_TYPE_CONTROL,
+	SNDRV_DEVICE_TYPE_SEQUENCER,
+	SNDRV_DEVICE_TYPE_TIMER,
+	SNDRV_DEVICE_TYPE_HWDEP,
+	SNDRV_DEVICE_TYPE_RAWMIDI,
+	SNDRV_DEVICE_TYPE_PCM_PLAYBACK,
+	SNDRV_DEVICE_TYPE_PCM_CAPTURE,
+	SNDRV_DEVICE_TYPE_COMPRESS,
+};
+
+#endif /* CONFIG_SND_DYNAMIC_MINORS */
+
+#define SNDRV_MINOR_HWDEPS		4
+#define SNDRV_MINOR_RAWMIDIS		8
+#define SNDRV_MINOR_PCMS		8
+
+
+#ifdef CONFIG_SND_OSSEMUL
+
+#define SNDRV_MINOR_OSS_DEVICES		16
+#define SNDRV_MINOR_OSS_CARD(minor)	((minor) >> 4)
+#define SNDRV_MINOR_OSS_DEVICE(minor)	((minor) & 0x000f)
+#define SNDRV_MINOR_OSS(card, dev)	(((card) << 4) | (dev))
+
+#define SNDRV_MINOR_OSS_MIXER		0	/* /dev/mixer - OSS 3.XX compatible */
+#define SNDRV_MINOR_OSS_SEQUENCER	1	/* /dev/sequencer - OSS 3.XX compatible */
+#define	SNDRV_MINOR_OSS_MIDI		2	/* /dev/midi - native midi interface - OSS 3.XX compatible - UART */
+#define SNDRV_MINOR_OSS_PCM		3	/* alias */
+#define SNDRV_MINOR_OSS_PCM_8		3	/* /dev/dsp - 8bit PCM - OSS 3.XX compatible */
+#define SNDRV_MINOR_OSS_AUDIO		4	/* /dev/audio - SunSparc compatible */
+#define SNDRV_MINOR_OSS_PCM_16		5	/* /dev/dsp16 - 16bit PCM - OSS 3.XX compatible */
+#define SNDRV_MINOR_OSS_SNDSTAT		6	/* /dev/sndstat - for compatibility with OSS */
+#define SNDRV_MINOR_OSS_RESERVED7	7	/* reserved for future use */
+#define SNDRV_MINOR_OSS_MUSIC		8	/* /dev/music - OSS 3.XX compatible */
+#define SNDRV_MINOR_OSS_DMMIDI		9	/* /dev/dmmidi0 - this device can have another minor # with OSS */
+#define SNDRV_MINOR_OSS_DMFM		10	/* /dev/dmfm0 - this device can have another minor # with OSS */
+#define SNDRV_MINOR_OSS_MIXER1		11	/* alternate mixer */
+#define SNDRV_MINOR_OSS_PCM1		12	/* alternate PCM (GF-A-1) */
+#define SNDRV_MINOR_OSS_MIDI1		13	/* alternate midi - SYNTH */
+#define SNDRV_MINOR_OSS_DMMIDI1		14	/* alternate dmmidi - SYNTH */
+#define SNDRV_MINOR_OSS_RESERVED15	15	/* reserved for future use */
+
+#define SNDRV_OSS_DEVICE_TYPE_MIXER	0
+#define SNDRV_OSS_DEVICE_TYPE_SEQUENCER	1
+#define SNDRV_OSS_DEVICE_TYPE_PCM	2
+#define SNDRV_OSS_DEVICE_TYPE_MIDI	3
+#define SNDRV_OSS_DEVICE_TYPE_DMFM	4
+#define SNDRV_OSS_DEVICE_TYPE_SNDSTAT	5
+#define SNDRV_OSS_DEVICE_TYPE_MUSIC	6
+
+#define MODULE_ALIAS_SNDRV_MINOR(type) \
+	MODULE_ALIAS("sound-service-?-" __stringify(type))
+
+#endif
+
+#endif /* __SOUND_MINORS_H */