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, 109 insertions, 0 deletions

diff --git a/include/sound/sdca_interrupts.h b/include/sound/sdca_interrupts.h
new file mode 100644
index 000000000..3b30146e2
--- /dev/null
+++ b/include/sound/sdca_interrupts.h
@@ -0,0 +1,109 @@
+/* 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_INTERRUPTS_H__
+#define __SDCA_INTERRUPTS_H__
+
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+
+struct device;
+struct snd_soc_component;
+struct sdca_function_data;
+
+#define SDCA_MAX_INTERRUPTS 31 /* the last bit is reserved for future extensions */
+
+/**
+ * struct sdca_interrupt - contains information about a single SDCA interrupt
+ * @name: The name of the interrupt.
+ * @dev: Pointer to the Function device.
+ * @device_regmap: Pointer to the IRQ regmap.
+ * @function_regmap: Pointer to the SDCA Function regmap.
+ * @component: Pointer to the ASoC component owns the interrupt.
+ * @function: Pointer to the Function that the interrupt is associated with.
+ * @entity: Pointer to the Entity that the interrupt is associated with.
+ * @control: Pointer to the Control that the interrupt is associated with.
+ * @handler: Handler function to be called for the IRQ.
+ * @priv: Pointer to private data for use by the handler.
+ * @free_priv: Pointer to a function that can be used to free the priv data.
+ * @irq: IRQ number allocated to this interrupt, also used internally to track
+ * the IRQ being assigned.
+ * @early_request: Flag to indicate this IRQ was requested at bus probe time.
+ */
+struct sdca_interrupt {
+	const char *name;
+
+	struct device *dev;
+	struct regmap *device_regmap;
+	struct regmap *function_regmap;
+	struct snd_soc_component *component;
+	struct sdca_function_data *function;
+	struct sdca_entity *entity;
+	struct sdca_control *control;
+	irq_handler_t handler;
+
+	void *priv;
+	void (*free_priv)(struct sdca_interrupt *interrupt);
+
+	int irq;
+	bool early_request;
+};
+
+/**
+ * struct sdca_interrupt_info - contains top-level SDCA interrupt information
+ * @irq_chip: regmap irq chip structure.
+ * @irq_data: regmap irq chip data structure.
+ * @irqs: Array of data for each individual IRQ.
+ * @irq_lock: Protects access to the list of sdca_interrupt structures.
+ */
+struct sdca_interrupt_info {
+	struct regmap_irq_chip irq_chip;
+	struct regmap_irq_chip_data *irq_data;
+
+	struct sdca_interrupt irqs[SDCA_MAX_INTERRUPTS];
+
+	struct mutex irq_lock; /* Protect irqs list across functions */
+};
+
+int sdca_irq_request(struct device *dev, struct sdca_interrupt_info *interrupt_info,
+		     int sdca_irq, const char *name, irq_handler_t handler,
+		     void *data);
+void sdca_irq_free(struct device *dev, struct sdca_interrupt_info *interrupt_info,
+		   int sdca_irq, const char *name, void *data);
+int sdca_irq_data_populate(struct device *dev, struct regmap *function_regmap,
+			   struct snd_soc_component *component,
+			   struct sdca_function_data *function,
+			   struct sdca_entity *entity,
+			   struct sdca_control *control,
+			   struct sdca_interrupt *interrupt);
+int sdca_irq_populate_early(struct device *dev, struct regmap *function_regmap,
+			    struct sdca_function_data *function,
+			    struct sdca_interrupt_info *info);
+int sdca_irq_populate(struct sdca_function_data *function,
+		      struct snd_soc_component *component,
+		      struct sdca_interrupt_info *info);
+void sdca_irq_cleanup(struct device *dev,
+		      struct sdca_function_data *function,
+		      struct sdca_interrupt_info *info);
+void sdca_irq_cleanup_late(struct device *dev,
+			   struct sdca_function_data *function,
+			   struct sdca_interrupt_info *info);
+
+struct sdca_interrupt_info *devm_sdca_irq_allocate(struct device *dev,
+						   struct regmap *regmap, int irq);
+
+void sdca_irq_enable_early(struct sdca_function_data *function,
+			   struct sdca_interrupt_info *info);
+void sdca_irq_enable(struct sdca_function_data *function,
+		     struct sdca_interrupt_info *info);
+void sdca_irq_disable(struct sdca_function_data *function,
+		      struct sdca_interrupt_info *info);
+
+#endif