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, 66 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/termbits-common.h b/include/uapi/asm-generic/termbits-common.h
new file mode 100644
index 000000000..4a6a79f28
--- /dev/null
+++ b/include/uapi/asm-generic/termbits-common.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_GENERIC_TERMBITS_COMMON_H
+#define __ASM_GENERIC_TERMBITS_COMMON_H
+
+typedef unsigned char	cc_t;
+typedef unsigned int	speed_t;
+
+/* c_iflag bits */
+#define IGNBRK	0x001			/* Ignore break condition */
+#define BRKINT	0x002			/* Signal interrupt on break */
+#define IGNPAR	0x004			/* Ignore characters with parity errors */
+#define PARMRK	0x008			/* Mark parity and framing errors */
+#define INPCK	0x010			/* Enable input parity check */
+#define ISTRIP	0x020			/* Strip 8th bit off characters */
+#define INLCR	0x040			/* Map NL to CR on input */
+#define IGNCR	0x080			/* Ignore CR */
+#define ICRNL	0x100			/* Map CR to NL on input */
+#define IXANY	0x800			/* Any character will restart after stop */
+
+/* c_oflag bits */
+#define OPOST	0x01			/* Perform output processing */
+#define OCRNL	0x08
+#define ONOCR	0x10
+#define ONLRET	0x20
+#define OFILL	0x40
+#define OFDEL	0x80
+
+/* c_cflag bit meaning */
+/* Common CBAUD rates */
+#define     B0		0x00000000	/* hang up */
+#define    B50		0x00000001
+#define    B75		0x00000002
+#define   B110		0x00000003
+#define   B134		0x00000004
+#define   B150		0x00000005
+#define   B200		0x00000006
+#define   B300		0x00000007
+#define   B600		0x00000008
+#define  B1200		0x00000009
+#define  B1800		0x0000000a
+#define  B2400		0x0000000b
+#define  B4800		0x0000000c
+#define  B9600		0x0000000d
+#define B19200		0x0000000e
+#define B38400		0x0000000f
+#define EXTA		B19200
+#define EXTB		B38400
+
+#define ADDRB		0x20000000	/* address bit */
+#define CMSPAR		0x40000000	/* mark or space (stick) parity */
+#define CRTSCTS		0x80000000	/* flow control */
+
+#define IBSHIFT		16		/* Shift from CBAUD to CIBAUD */
+
+/* tcflow() ACTION argument and TCXONC use these */
+#define TCOOFF		0		/* Suspend output */
+#define TCOON		1		/* Restart suspended output */
+#define TCIOFF		2		/* Send a STOP character */
+#define TCION		3		/* Send a START character */
+
+/* tcflush() QUEUE_SELECTOR argument and TCFLSH use these */
+#define TCIFLUSH	0		/* Discard data received but not yet read */
+#define TCOFLUSH	1		/* Discard data written but not yet sent */
+#define TCIOFLUSH	2		/* Discard all pending data */
+
+#endif /* __ASM_GENERIC_TERMBITS_COMMON_H */