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, 108 insertions, 0 deletions

diff --git a/include/uapi/sound/tlv.h b/include/uapi/sound/tlv.h
new file mode 100644
index 000000000..5bb55c80e
--- /dev/null
+++ b/include/uapi/sound/tlv.h
@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+
+#ifndef __UAPI_SOUND_TLV_H
+#define __UAPI_SOUND_TLV_H
+
+#define SNDRV_CTL_TLVT_CONTAINER 0	/* one level down - group of TLVs */
+#define SNDRV_CTL_TLVT_DB_SCALE	1       /* dB scale */
+#define SNDRV_CTL_TLVT_DB_LINEAR 2	/* linear volume */
+#define SNDRV_CTL_TLVT_DB_RANGE 3	/* dB range container */
+#define SNDRV_CTL_TLVT_DB_MINMAX 4	/* dB scale with min/max */
+#define SNDRV_CTL_TLVT_DB_MINMAX_MUTE 5	/* dB scale with min/max with mute */
+
+/*
+ * channel-mapping TLV items
+ *  TLV length must match with num_channels
+ */
+#define SNDRV_CTL_TLVT_CHMAP_FIXED	0x101	/* fixed channel position */
+#define SNDRV_CTL_TLVT_CHMAP_VAR	0x102	/* channels freely swappable */
+#define SNDRV_CTL_TLVT_CHMAP_PAIRED	0x103	/* pair-wise swappable */
+
+#define SNDRV_CTL_TLVT_FCP_CHANNEL_LABELS	0x110	/* channel labels */
+
+/*
+ * TLV structure is right behind the struct snd_ctl_tlv:
+ *   unsigned int type  	- see SNDRV_CTL_TLVT_*
+ *   unsigned int length
+ *   .... data aligned to sizeof(unsigned int), use
+ *        block_length = (length + (sizeof(unsigned int) - 1)) &
+ *                       ~(sizeof(unsigned int) - 1)) ....
+ */
+#define SNDRV_CTL_TLVD_ITEM(type, ...) \
+	(type), SNDRV_CTL_TLVD_LENGTH(__VA_ARGS__), __VA_ARGS__
+#define SNDRV_CTL_TLVD_LENGTH(...) \
+	((unsigned int)sizeof((const unsigned int[]) { __VA_ARGS__ }))
+
+/* Accessor offsets for TLV data items */
+#define SNDRV_CTL_TLVO_TYPE		0
+#define SNDRV_CTL_TLVO_LEN		1
+
+#define SNDRV_CTL_TLVD_CONTAINER_ITEM(...) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_CONTAINER, __VA_ARGS__)
+#define SNDRV_CTL_TLVD_DECLARE_CONTAINER(name, ...) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_CONTAINER_ITEM(__VA_ARGS__) \
+	}
+
+#define SNDRV_CTL_TLVD_DB_SCALE_MASK	0xffff
+#define SNDRV_CTL_TLVD_DB_SCALE_MUTE	0x10000
+#define SNDRV_CTL_TLVD_DB_SCALE_ITEM(min, step, mute) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_SCALE, \
+			    (min), \
+			    ((step) & SNDRV_CTL_TLVD_DB_SCALE_MASK) | \
+			     ((mute) ? SNDRV_CTL_TLVD_DB_SCALE_MUTE : 0))
+#define SNDRV_CTL_TLVD_DECLARE_DB_SCALE(name, min, step, mute) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_SCALE_ITEM(min, step, mute) \
+	}
+
+/* Accessor offsets for min, mute and step items in dB scale type TLV */
+#define SNDRV_CTL_TLVO_DB_SCALE_MIN		2
+#define SNDRV_CTL_TLVO_DB_SCALE_MUTE_AND_STEP	3
+
+/* dB scale specified with min/max values instead of step */
+#define SNDRV_CTL_TLVD_DB_MINMAX_ITEM(min_dB, max_dB) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_MINMAX, (min_dB), (max_dB))
+#define SNDRV_CTL_TLVD_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_MINMAX_MUTE, (min_dB), (max_dB))
+#define SNDRV_CTL_TLVD_DECLARE_DB_MINMAX(name, min_dB, max_dB) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_MINMAX_ITEM(min_dB, max_dB) \
+	}
+#define SNDRV_CTL_TLVD_DECLARE_DB_MINMAX_MUTE(name, min_dB, max_dB) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_MINMAX_MUTE_ITEM(min_dB, max_dB) \
+	}
+
+/* Accessor offsets for min, max items in db-minmax types of TLV. */
+#define SNDRV_CTL_TLVO_DB_MINMAX_MIN	2
+#define SNDRV_CTL_TLVO_DB_MINMAX_MAX	3
+
+/* linear volume between min_dB and max_dB (.01dB unit) */
+#define SNDRV_CTL_TLVD_DB_LINEAR_ITEM(min_dB, max_dB) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_LINEAR, (min_dB), (max_dB))
+#define SNDRV_CTL_TLVD_DECLARE_DB_LINEAR(name, min_dB, max_dB) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_LINEAR_ITEM(min_dB, max_dB) \
+	}
+
+/* Accessor offsets for min, max items in db-linear type of TLV. */
+#define SNDRV_CTL_TLVO_DB_LINEAR_MIN	2
+#define SNDRV_CTL_TLVO_DB_LINEAR_MAX	3
+
+/* dB range container:
+ * Items in dB range container must be ordered by their values and by their
+ * dB values. This implies that larger values must correspond with larger
+ * dB values (which is also required for all other mixer controls).
+ */
+/* Each item is: <min> <max> <TLV> */
+#define SNDRV_CTL_TLVD_DB_RANGE_ITEM(...) \
+	SNDRV_CTL_TLVD_ITEM(SNDRV_CTL_TLVT_DB_RANGE, __VA_ARGS__)
+#define SNDRV_CTL_TLVD_DECLARE_DB_RANGE(name, ...) \
+	unsigned int name[] = { \
+		SNDRV_CTL_TLVD_DB_RANGE_ITEM(__VA_ARGS__) \
+	}
+
+#define SNDRV_CTL_TLVD_DB_GAIN_MUTE	-9999999
+
+#endif