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, 45 insertions, 0 deletions

diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
new file mode 100644
index 000000000..e31cab4ba
--- /dev/null
+++ b/drivers/power/reset/Makefile
@@ -0,0 +1,45 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o
+obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o
+obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o
+obj-$(CONFIG_POWER_RESET_AT91_SAMA5D2_SHDWC) += at91-sama5d2_shdwc.o
+obj-$(CONFIG_POWER_RESET_ATC260X) += atc260x-poweroff.o
+obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
+obj-$(CONFIG_POWER_RESET_BRCMKONA) += brcm-kona-reset.o
+obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
+obj-$(CONFIG_POWER_RESET_EP93XX) += ep93xx-restart.o
+obj-$(CONFIG_POWER_RESET_GEMINI_POWEROFF) += gemini-poweroff.o
+obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
+obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
+obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
+obj-$(CONFIG_POWER_RESET_LINKSTATION) += linkstation-poweroff.o
+obj-$(CONFIG_POWER_RESET_MCF_RCM) += mcf-rcm-reset.o
+obj-$(CONFIG_POWER_RESET_MACSMC) += macsmc-reboot.o
+obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
+obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o
+obj-$(CONFIG_POWER_RESET_QCOM_PON) += qcom-pon.o
+obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
+obj-$(CONFIG_POWER_RESET_ODROID_GO_ULTRA_POWEROFF) += odroid-go-ultra-poweroff.o
+obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o
+obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
+obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
+obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o
+obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
+obj-$(CONFIG_POWER_RESET_SPACEMIT_P1) += spacemit-p1-reboot.o
+obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o
+obj-$(CONFIG_POWER_RESET_TH1520_AON) += th1520-aon-reboot.o
+obj-$(CONFIG_POWER_RESET_TORADEX_EC) += tdx-ec-poweroff.o
+obj-$(CONFIG_POWER_RESET_TPS65086) += tps65086-restart.o
+obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
+obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
+obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
+obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o
+obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o
+obj-$(CONFIG_POWER_RESET_SYSCON_POWEROFF) += syscon-poweroff.o
+obj-$(CONFIG_POWER_RESET_RMOBILE) += rmobile-reset.o
+obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o
+obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
+obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
+obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o
+obj-$(CONFIG_POWER_MLXBF) += pwr-mlxbf.o
+obj-$(CONFIG_POWER_RESET_QEMU_VIRT_CTRL) += qemu-virt-ctrl.o