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, 34 insertions, 0 deletions

diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
new file mode 100644
index 000000000..7b6dd53e8
--- /dev/null
+++ b/drivers/mtd/Makefile
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the memory technology device drivers.
+#
+
+# Core functionality.
+obj-$(CONFIG_MTD)		+= mtd.o
+mtd-y				:= mtdcore.o mtdsuper.o mtdconcat.o mtdpart.o mtdchar.o
+mtd-$(CONFIG_MTD_VIRT_CONCAT)	+= mtd_virt_concat.o
+
+obj-y				+= parsers/
+
+# 'Users' - code which presents functionality to userspace.
+obj-$(CONFIG_MTD_BLKDEVS)	+= mtd_blkdevs.o
+obj-$(CONFIG_MTD_BLOCK)		+= mtdblock.o
+obj-$(CONFIG_MTD_BLOCK_RO)	+= mtdblock_ro.o
+obj-$(CONFIG_FTL)		+= ftl.o
+obj-$(CONFIG_NFTL)		+= nftl.o
+obj-$(CONFIG_INFTL)		+= inftl.o
+obj-$(CONFIG_RFD_FTL)		+= rfd_ftl.o
+obj-$(CONFIG_SSFDC)		+= ssfdc.o
+obj-$(CONFIG_SM_FTL)		+= sm_ftl.o
+obj-$(CONFIG_MTD_OOPS)		+= mtdoops.o
+obj-$(CONFIG_MTD_PSTORE)	+= mtdpstore.o
+obj-$(CONFIG_MTD_SWAP)		+= mtdswap.o
+
+nftl-objs		:= nftlcore.o nftlmount.o
+inftl-objs		:= inftlcore.o inftlmount.o
+
+obj-y		+= chips/ lpddr/ maps/ devices/ nand/ tests/
+
+obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor/
+obj-$(CONFIG_MTD_UBI)		+= ubi/
+obj-$(CONFIG_MTD_HYPERBUS)	+= hyperbus/