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, 171 insertions, 0 deletions

diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.h b/drivers/phy/broadcom/phy-brcm-usb-init.h
new file mode 100644
index 000000000..4c7be78d0
--- /dev/null
+++ b/drivers/phy/broadcom/phy-brcm-usb-init.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2014-2017 Broadcom
+ */
+
+#ifndef _USB_BRCM_COMMON_INIT_H
+#define _USB_BRCM_COMMON_INIT_H
+
+#include <linux/regmap.h>
+
+#define USB_CTLR_MODE_HOST 0
+#define USB_CTLR_MODE_DEVICE 1
+#define USB_CTLR_MODE_DRD 2
+#define USB_CTLR_MODE_TYPEC_PD 3
+
+enum brcmusb_reg_sel {
+	BRCM_REGS_CTRL = 0,
+	BRCM_REGS_XHCI_EC,
+	BRCM_REGS_XHCI_GBL,
+	BRCM_REGS_USB_PHY,
+	BRCM_REGS_USB_MDIO,
+	BRCM_REGS_BDC_EC,
+	BRCM_REGS_MAX
+};
+
+#define USB_CTRL_REG(base, reg)	((void __iomem *)base + USB_CTRL_##reg)
+#define USB_XHCI_EC_REG(base, reg) ((void __iomem *)base + USB_XHCI_EC_##reg)
+#define USB_CTRL_MASK(reg, field) \
+	USB_CTRL_##reg##_##field##_MASK
+#define USB_CTRL_SET(base, reg, field)	\
+	brcm_usb_ctrl_set(USB_CTRL_REG(base, reg),	\
+			  USB_CTRL_##reg##_##field##_MASK)
+#define USB_CTRL_UNSET(base, reg, field)	\
+	brcm_usb_ctrl_unset(USB_CTRL_REG(base, reg),		\
+			    USB_CTRL_##reg##_##field##_MASK)
+
+#define USB_XHCI_GBL_REG(base, reg) ((void __iomem *)base + USB_XHCI_GBL_##reg)
+#define USB_XHCI_GBL_SET(base, reg, field) \
+	brcm_usb_ctrl_set(USB_XHCI_GBL_REG(base, reg), \
+			  USB_XHCI_GBL_##reg##_##field##_MASK)
+#define USB_XHCI_GBL_UNSET(base, reg, field) \
+	brcm_usb_ctrl_unset(USB_XHCI_GBL_REG(base, reg), \
+			    USB_XHCI_GBL_##reg##_##field##_MASK)
+
+struct  brcm_usb_init_params;
+
+struct brcm_usb_init_ops {
+	void (*init_ipp)(struct brcm_usb_init_params *params);
+	void (*init_common)(struct brcm_usb_init_params *params);
+	void (*init_eohci)(struct brcm_usb_init_params *params);
+	void (*init_xhci)(struct brcm_usb_init_params *params);
+	void (*uninit_common)(struct brcm_usb_init_params *params);
+	void (*uninit_eohci)(struct brcm_usb_init_params *params);
+	void (*uninit_xhci)(struct brcm_usb_init_params *params);
+	int  (*get_dual_select)(struct brcm_usb_init_params *params);
+	void (*set_dual_select)(struct brcm_usb_init_params *params);
+};
+
+struct  brcm_usb_init_params {
+	void __iomem *regs[BRCM_REGS_MAX];
+	int ioc;
+	int ipp;
+	int supported_port_modes;
+	int port_mode;
+	u32 family_id;
+	u32 product_id;
+	int selected_family;
+	const char *family_name;
+	const u32 *usb_reg_bits_map;
+	const struct brcm_usb_init_ops *ops;
+	struct regmap *syscon_piarbctl;
+	bool wake_enabled;
+};
+
+void brcm_usb_dvr_init_74110(struct brcm_usb_init_params *params);
+void brcm_usb_dvr_init_4908(struct brcm_usb_init_params *params);
+void brcm_usb_dvr_init_7445(struct brcm_usb_init_params *params);
+void brcm_usb_dvr_init_7216(struct brcm_usb_init_params *params);
+void brcm_usb_dvr_init_7211b0(struct brcm_usb_init_params *params);
+
+static inline u32 brcm_usb_readl(void __iomem *addr)
+{
+	/*
+	 * MIPS endianness is configured by boot strap, which also reverses all
+	 * bus endianness (i.e., big-endian CPU + big endian bus ==> native
+	 * endian I/O).
+	 *
+	 * Other architectures (e.g., ARM) either do not support big endian, or
+	 * else leave I/O in little endian mode.
+	 */
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		return __raw_readl(addr);
+	else
+		return readl_relaxed(addr);
+}
+
+static inline void brcm_usb_writel(u32 val, void __iomem *addr)
+{
+	/* See brcmnand_readl() comments */
+	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+		__raw_writel(val, addr);
+	else
+		writel_relaxed(val, addr);
+}
+
+static inline void brcm_usb_ctrl_unset(void __iomem *reg, u32 mask)
+{
+	brcm_usb_writel(brcm_usb_readl(reg) & ~(mask), reg);
+};
+
+static inline void brcm_usb_ctrl_set(void __iomem *reg, u32 mask)
+{
+	brcm_usb_writel(brcm_usb_readl(reg) | (mask), reg);
+};
+
+static inline void brcm_usb_init_ipp(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->init_ipp)
+		ini->ops->init_ipp(ini);
+}
+
+static inline void brcm_usb_init_common(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->init_common)
+		ini->ops->init_common(ini);
+}
+
+static inline void brcm_usb_init_eohci(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->init_eohci)
+		ini->ops->init_eohci(ini);
+}
+
+static inline void brcm_usb_init_xhci(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->init_xhci)
+		ini->ops->init_xhci(ini);
+}
+
+static inline void brcm_usb_uninit_common(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->uninit_common)
+		ini->ops->uninit_common(ini);
+}
+
+static inline void brcm_usb_uninit_eohci(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->uninit_eohci)
+		ini->ops->uninit_eohci(ini);
+}
+
+static inline void brcm_usb_uninit_xhci(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->uninit_xhci)
+		ini->ops->uninit_xhci(ini);
+}
+
+static inline int brcm_usb_get_dual_select(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->get_dual_select)
+		return ini->ops->get_dual_select(ini);
+	return 0;
+}
+
+static inline void brcm_usb_set_dual_select(struct brcm_usb_init_params *ini)
+{
+	if (ini->ops->set_dual_select)
+		ini->ops->set_dual_select(ini);
+}
+
+#endif /* _USB_BRCM_COMMON_INIT_H */