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, 231 insertions, 0 deletions

diff --git a/include/sound/hda-mlink.h b/include/sound/hda-mlink.h
new file mode 100644
index 000000000..ba35f0357
--- /dev/null
+++ b/include/sound/hda-mlink.h
@@ -0,0 +1,231 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
+/*
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Copyright(c) 2022-2023 Intel Corporation
+ */
+
+struct hdac_bus;
+struct hdac_ext_link;
+
+/**
+ * enum hda_bus_ml_link_type - mlink link type, used by SOF link DMA
+ *	allocator constraints (see struct sof_intel_hda_dev).
+ *
+ * @HDA_BUS_ML_LINK_HDA:  non-alt link, i.e. HDA codec or iDisp
+ * @HDA_BUS_ML_LINK_SDW:  alt link, SoundWire
+ * @HDA_BUS_ML_LINK_UAOL: alt link, USB Audio Offload
+ * @HDA_BUS_ML_LINK_OTHER: alt link, SSP or DMIC
+ */
+enum hda_bus_ml_link_type {
+	HDA_BUS_ML_LINK_HDA,
+	HDA_BUS_ML_LINK_SDW,
+	HDA_BUS_ML_LINK_UAOL,
+	HDA_BUS_ML_LINK_OTHER,
+};
+
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_MLINK)
+
+int hda_bus_ml_init(struct hdac_bus *bus);
+void hda_bus_ml_free(struct hdac_bus *bus);
+
+int hdac_bus_eml_get_count(struct hdac_bus *bus, bool alt, int elid);
+void hdac_bus_eml_enable_interrupt_unlocked(struct hdac_bus *bus, bool alt, int elid, bool enable);
+void hdac_bus_eml_enable_interrupt(struct hdac_bus *bus, bool alt, int elid, bool enable);
+bool hdac_bus_eml_check_interrupt(struct hdac_bus *bus, bool alt, int elid);
+
+int hdac_bus_eml_set_syncprd_unlocked(struct hdac_bus *bus, bool alt, int elid, u32 syncprd);
+int hdac_bus_eml_sdw_set_syncprd_unlocked(struct hdac_bus *bus, u32 syncprd);
+
+int hdac_bus_eml_wait_syncpu_unlocked(struct hdac_bus *bus, bool alt, int elid);
+int hdac_bus_eml_sdw_wait_syncpu_unlocked(struct hdac_bus *bus);
+
+void hdac_bus_eml_sync_arm_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink);
+void hdac_bus_eml_sdw_sync_arm_unlocked(struct hdac_bus *bus, int sublink);
+
+int hdac_bus_eml_sync_go_unlocked(struct hdac_bus *bus, bool alt, int elid);
+int hdac_bus_eml_sdw_sync_go_unlocked(struct hdac_bus *bus);
+
+bool hdac_bus_eml_check_cmdsync_unlocked(struct hdac_bus *bus, bool alt, int elid);
+bool hdac_bus_eml_sdw_check_cmdsync_unlocked(struct hdac_bus *bus);
+
+int hdac_bus_eml_power_up(struct hdac_bus *bus, bool alt, int elid, int sublink);
+int hdac_bus_eml_power_up_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink);
+
+int hdac_bus_eml_power_down(struct hdac_bus *bus, bool alt, int elid, int sublink);
+int hdac_bus_eml_power_down_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink);
+
+int hdac_bus_eml_sdw_power_up_unlocked(struct hdac_bus *bus, int sublink);
+int hdac_bus_eml_sdw_power_down_unlocked(struct hdac_bus *bus, int sublink);
+
+int hdac_bus_eml_sdw_get_lsdiid_unlocked(struct hdac_bus *bus, int sublink, u16 *lsdiid);
+int hdac_bus_eml_sdw_set_lsdiid(struct hdac_bus *bus, int sublink, int dev_num);
+
+int hdac_bus_eml_sdw_map_stream_ch(struct hdac_bus *bus, int sublink, int y,
+				   int channel_mask, int stream_id, int dir);
+
+void hda_bus_ml_reset_losidv(struct hdac_bus *bus);
+int hda_bus_ml_resume(struct hdac_bus *bus);
+int hda_bus_ml_suspend(struct hdac_bus *bus);
+
+enum hda_bus_ml_link_type hda_bus_ml_link_get_type(struct hdac_ext_link *hlink);
+
+struct hdac_ext_link *hdac_bus_eml_ssp_get_hlink(struct hdac_bus *bus);
+struct hdac_ext_link *hdac_bus_eml_dmic_get_hlink(struct hdac_bus *bus);
+struct hdac_ext_link *hdac_bus_eml_sdw_get_hlink(struct hdac_bus *bus);
+
+struct mutex *hdac_bus_eml_get_mutex(struct hdac_bus *bus, bool alt, int elid);
+
+void hdac_bus_eml_enable_offload(struct hdac_bus *bus, bool alt, int elid, bool enable);
+
+/* microphone privacy specific function supported by ACE3+ architecture */
+void hdac_bus_eml_set_mic_privacy_mask(struct hdac_bus *bus, bool alt, int elid,
+				       unsigned long mask);
+bool hdac_bus_eml_is_mic_privacy_changed(struct hdac_bus *bus, bool alt, int elid);
+bool hdac_bus_eml_get_mic_privacy_state(struct hdac_bus *bus, bool alt, int elid);
+
+#else
+
+static inline int
+hda_bus_ml_init(struct hdac_bus *bus) { return 0; }
+
+static inline void hda_bus_ml_free(struct hdac_bus *bus) { }
+
+static inline int
+hdac_bus_eml_get_count(struct hdac_bus *bus, bool alt, int elid) { return 0; }
+
+static inline void
+hdac_bus_eml_enable_interrupt_unlocked(struct hdac_bus *bus, bool alt, int elid, bool enable) { }
+
+static inline void
+hdac_bus_eml_enable_interrupt(struct hdac_bus *bus, bool alt, int elid, bool enable) { }
+
+static inline bool
+hdac_bus_eml_check_interrupt(struct hdac_bus *bus, bool alt, int elid) { return false; }
+
+static inline int
+hdac_bus_eml_set_syncprd_unlocked(struct hdac_bus *bus, bool alt, int elid, u32 syncprd)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_sdw_set_syncprd_unlocked(struct hdac_bus *bus, u32 syncprd)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_wait_syncpu_unlocked(struct hdac_bus *bus, bool alt, int elid)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_sdw_wait_syncpu_unlocked(struct hdac_bus *bus) { return 0; }
+
+static inline void
+hdac_bus_eml_sync_arm_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink) { }
+
+static inline void
+hdac_bus_eml_sdw_sync_arm_unlocked(struct hdac_bus *bus, int sublink) { }
+
+static inline int
+hdac_bus_eml_sync_go_unlocked(struct hdac_bus *bus, bool alt, int elid) { return 0; }
+
+static inline int
+hdac_bus_eml_sdw_sync_go_unlocked(struct hdac_bus *bus) { return 0; }
+
+static inline bool
+hdac_bus_eml_check_cmdsync_unlocked(struct hdac_bus *bus, bool alt, int elid) { return false; }
+
+static inline bool
+hdac_bus_eml_sdw_check_cmdsync_unlocked(struct hdac_bus *bus) { return false; }
+
+static inline int
+hdac_bus_eml_power_up(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_power_up_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_power_down(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_power_down_unlocked(struct hdac_bus *bus, bool alt, int elid, int sublink)
+{
+	return 0;
+}
+
+static inline int
+hdac_bus_eml_sdw_power_up_unlocked(struct hdac_bus *bus, int sublink) { return 0; }
+
+static inline int
+hdac_bus_eml_sdw_power_down_unlocked(struct hdac_bus *bus, int sublink) { return 0; }
+
+static inline int
+hdac_bus_eml_sdw_get_lsdiid_unlocked(struct hdac_bus *bus, int sublink, u16 *lsdiid) { return 0; }
+
+static inline int
+hdac_bus_eml_sdw_set_lsdiid(struct hdac_bus *bus, int sublink, int dev_num) { return 0; }
+
+static inline int
+hdac_bus_eml_sdw_map_stream_ch(struct hdac_bus *bus, int sublink, int y,
+			       int channel_mask, int stream_id, int dir)
+{
+	return 0;
+}
+
+static inline void hda_bus_ml_reset_losidv(struct hdac_bus *bus) { }
+static inline int hda_bus_ml_resume(struct hdac_bus *bus) { return 0; }
+static inline int hda_bus_ml_suspend(struct hdac_bus *bus) { return 0; }
+
+static inline enum hda_bus_ml_link_type
+hda_bus_ml_link_get_type(struct hdac_ext_link *hlink) { return HDA_BUS_ML_LINK_HDA; }
+
+static inline struct hdac_ext_link *
+hdac_bus_eml_ssp_get_hlink(struct hdac_bus *bus) { return NULL; }
+
+static inline struct hdac_ext_link *
+hdac_bus_eml_dmic_get_hlink(struct hdac_bus *bus) { return NULL; }
+
+static inline struct hdac_ext_link *
+hdac_bus_eml_sdw_get_hlink(struct hdac_bus *bus) { return NULL; }
+
+static inline struct mutex *
+hdac_bus_eml_get_mutex(struct hdac_bus *bus, bool alt, int elid) { return NULL; }
+
+static inline void
+hdac_bus_eml_enable_offload(struct hdac_bus *bus, bool alt, int elid, bool enable)
+{
+}
+
+static inline void
+hdac_bus_eml_set_mic_privacy_mask(struct hdac_bus *bus, bool alt, int elid,
+				  unsigned long mask)
+{
+}
+
+static inline bool
+hdac_bus_eml_is_mic_privacy_changed(struct hdac_bus *bus, bool alt, int elid)
+{
+	return false;
+}
+
+static inline bool
+hdac_bus_eml_get_mic_privacy_state(struct hdac_bus *bus, bool alt, int elid)
+{
+	return false;
+}
+
+#endif /* CONFIG_SND_SOC_SOF_HDA_MLINK */