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, 125 insertions, 0 deletions

diff --git a/include/pcmcia/soc_common.h b/include/pcmcia/soc_common.h
new file mode 100644
index 000000000..d4f18f467
--- /dev/null
+++ b/include/pcmcia/soc_common.h
@@ -0,0 +1,125 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <pcmcia/ss.h>
+
+struct module;
+struct cpufreq_freqs;
+
+struct soc_pcmcia_regulator {
+	struct regulator	*reg;
+	bool			on;
+};
+
+struct pcmcia_state {
+  unsigned detect: 1,
+            ready: 1,
+             bvd1: 1,
+             bvd2: 1,
+           wrprot: 1,
+            vs_3v: 1,
+            vs_Xv: 1;
+};
+
+/*
+ * This structure encapsulates per-socket state which we might need to
+ * use when responding to a Card Services query of some kind.
+ */
+struct soc_pcmcia_socket {
+	struct pcmcia_socket	socket;
+
+	/*
+	 * Info from low level handler
+	 */
+	unsigned int		nr;
+	struct clk		*clk;
+
+	/*
+	 * Core PCMCIA state
+	 */
+	const struct pcmcia_low_level *ops;
+
+	unsigned int		status;
+	socket_state_t		cs_state;
+
+	unsigned short		spd_io[MAX_IO_WIN];
+	unsigned short		spd_mem[MAX_WIN];
+	unsigned short		spd_attr[MAX_WIN];
+
+	struct resource		res_skt;
+	struct resource		res_io;
+	struct resource		res_io_io;
+	struct resource		res_mem;
+	struct resource		res_attr;
+
+	struct {
+		int		gpio;
+		struct gpio_desc *desc;
+		unsigned int	irq;
+		const char	*name;
+	} stat[6];
+#define SOC_STAT_CD		0	/* Card detect */
+#define SOC_STAT_BVD1		1	/* BATDEAD / IOSTSCHG */
+#define SOC_STAT_BVD2		2	/* BATWARN / IOSPKR */
+#define SOC_STAT_RDY		3	/* Ready / Interrupt */
+#define SOC_STAT_VS1		4	/* Voltage sense 1 */
+#define SOC_STAT_VS2		5	/* Voltage sense 2 */
+
+	struct gpio_desc	*gpio_reset;
+	struct gpio_desc	*gpio_bus_enable;
+	struct soc_pcmcia_regulator vcc;
+	struct soc_pcmcia_regulator vpp;
+
+	unsigned int		irq_state;
+
+#ifdef CONFIG_CPU_FREQ
+	struct notifier_block	cpufreq_nb;
+#endif
+	struct timer_list	poll_timer;
+	struct list_head	node;
+	void *driver_data;
+};
+
+
+struct pcmcia_low_level {
+	struct module *owner;
+
+	/* first socket in system */
+	int first;
+	/* nr of sockets */
+	int nr;
+
+	int (*hw_init)(struct soc_pcmcia_socket *);
+	void (*hw_shutdown)(struct soc_pcmcia_socket *);
+
+	void (*socket_state)(struct soc_pcmcia_socket *, struct pcmcia_state *);
+	int (*configure_socket)(struct soc_pcmcia_socket *, const socket_state_t *);
+
+	/*
+	 * Enable card status IRQs on (re-)initialisation.  This can
+	 * be called at initialisation, power management event, or
+	 * pcmcia event.
+	 */
+	void (*socket_init)(struct soc_pcmcia_socket *);
+
+	/*
+	 * Disable card status IRQs and PCMCIA bus on suspend.
+	 */
+	void (*socket_suspend)(struct soc_pcmcia_socket *);
+
+	/*
+	 * Hardware specific timing routines.
+	 * If provided, the get_timing routine overrides the SOC default.
+	 */
+	unsigned int (*get_timing)(struct soc_pcmcia_socket *, unsigned int, unsigned int);
+	int (*set_timing)(struct soc_pcmcia_socket *);
+	int (*show_timing)(struct soc_pcmcia_socket *, char *);
+
+#ifdef CONFIG_CPU_FREQ
+	/*
+	 * CPUFREQ support.
+	 */
+	int (*frequency_change)(struct soc_pcmcia_socket *, unsigned long, struct cpufreq_freqs *);
+#endif
+};
+
+
+