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, 111 insertions, 0 deletions

diff --git a/include/sound/sdca_fdl.h b/include/sound/sdca_fdl.h
new file mode 100644
index 000000000..bc3600cdd
--- /dev/null
+++ b/include/sound/sdca_fdl.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The MIPI SDCA specification is available for public downloads at
+ * https://www.mipi.org/mipi-sdca-v1-0-download
+ *
+ * Copyright (C) 2025 Cirrus Logic, Inc. and
+ *                    Cirrus Logic International Semiconductor Ltd.
+ */
+
+#ifndef __SDCA_FDL_H__
+#define __SDCA_FDL_H__
+
+#include <linux/completion.h>
+#include <linux/workqueue.h>
+
+struct device;
+struct regmap;
+struct sdca_fdl_set;
+struct sdca_function_data;
+struct sdca_interrupt;
+struct sdca_interrupt_info;
+
+/**
+ * struct fdl_state - FDL state structure to keep data between interrupts
+ * @begin: Completion indicating the start of an FDL download cycle.
+ * @done: Completion indicating the end of an FDL download cycle.
+ * @timeout: Delayed work used for timing out UMP transactions.
+ * @lock: Mutex to protect between the timeout work and IRQ handlers.
+ * @interrupt: Pointer to the interrupt struct to which this FDL is attached.
+ * @set: Pointer to the FDL set currently being downloaded.
+ * @file_index: Index of the current file being processed.
+ */
+struct fdl_state {
+	struct completion begin;
+	struct completion done;
+	struct delayed_work timeout;
+	struct mutex lock;
+
+	struct sdca_interrupt *interrupt;
+	struct sdca_fdl_set *set;
+	int file_index;
+};
+
+#define SDCA_CTL_XU_FDLH_COMPLETE	0
+#define SDCA_CTL_XU_FDLH_MORE_FILES	SDCA_CTL_XU_FDLH_SET_IN_PROGRESS
+#define SDCA_CTL_XU_FDLH_FILE_AVAILABLE	(SDCA_CTL_XU_FDLH_TRANSFERRED_FILE | \
+					 SDCA_CTL_XU_FDLH_SET_IN_PROGRESS)
+#define SDCA_CTL_XU_FDLH_MASK		(SDCA_CTL_XU_FDLH_TRANSFERRED_CHUNK | \
+					 SDCA_CTL_XU_FDLH_TRANSFERRED_FILE | \
+					 SDCA_CTL_XU_FDLH_SET_IN_PROGRESS | \
+					 SDCA_CTL_XU_FDLH_RESET_ACK | \
+					 SDCA_CTL_XU_FDLH_REQ_ABORT)
+
+#define SDCA_CTL_XU_FDLD_COMPLETE	0
+#define SDCA_CTL_XU_FDLD_FILE_OK	(SDCA_CTL_XU_FDLH_TRANSFERRED_FILE | \
+					 SDCA_CTL_XU_FDLH_SET_IN_PROGRESS | \
+					 SDCA_CTL_XU_FDLD_ACK_TRANSFER | \
+					 SDCA_CTL_XU_FDLD_NEEDS_SET)
+#define SDCA_CTL_XU_FDLD_MORE_FILES_OK	(SDCA_CTL_XU_FDLH_SET_IN_PROGRESS | \
+					 SDCA_CTL_XU_FDLD_ACK_TRANSFER | \
+					 SDCA_CTL_XU_FDLD_NEEDS_SET)
+#define SDCA_CTL_XU_FDLD_MASK		(SDCA_CTL_XU_FDLD_REQ_RESET | \
+					 SDCA_CTL_XU_FDLD_REQ_ABORT | \
+					 SDCA_CTL_XU_FDLD_ACK_TRANSFER | \
+					 SDCA_CTL_XU_FDLD_NEEDS_SET)
+
+#if IS_ENABLED(CONFIG_SND_SOC_SDCA_FDL)
+
+int sdca_fdl_alloc_state(struct sdca_interrupt *interrupt);
+void sdca_fdl_free_state(struct sdca_interrupt *interrupt);
+
+int sdca_fdl_process(struct sdca_interrupt *interrupt);
+int sdca_fdl_sync(struct device *dev, struct sdca_function_data *function,
+		  struct sdca_interrupt_info *info);
+
+int sdca_reset_function(struct device *dev, struct sdca_function_data *function,
+			struct regmap *regmap);
+
+#else
+
+static inline int sdca_fdl_alloc_state(struct sdca_interrupt *interrupt)
+{
+	return 0;
+}
+
+static inline void sdca_fdl_free_state(struct sdca_interrupt *interrupt)
+{
+}
+
+static inline int sdca_fdl_process(struct sdca_interrupt *interrupt)
+{
+	return 0;
+}
+
+static inline int sdca_fdl_sync(struct device *dev,
+				struct sdca_function_data *function,
+				struct sdca_interrupt_info *info)
+{
+	return 0;
+}
+
+static inline int sdca_reset_function(struct device *dev,
+				      struct sdca_function_data *function,
+				      struct regmap *regmap)
+{
+	return 0;
+}
+
+#endif // CONFIG_SND_SOC_SDCA_FDL
+
+#endif // __SDCA_FDL_H__