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

12 files changed, 12 insertions, 0 deletions

diff --git a/scripts/dtc/include-prefixes/arc b/scripts/dtc/include-prefixes/arc
new file mode 120000
index 000000000..5d21b5a69
--- /dev/null
+++ b/scripts/dtc/include-prefixes/arc
@@ -0,0 +1 @@
+../../../arch/arc/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/arm b/scripts/dtc/include-prefixes/arm
new file mode 120000
index 000000000..eb14d4515
--- /dev/null
+++ b/scripts/dtc/include-prefixes/arm
@@ -0,0 +1 @@
+../../../arch/arm/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/arm64 b/scripts/dtc/include-prefixes/arm64
new file mode 120000
index 000000000..275c42c21
--- /dev/null
+++ b/scripts/dtc/include-prefixes/arm64
@@ -0,0 +1 @@
+../../../arch/arm64/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/dt-bindings b/scripts/dtc/include-prefixes/dt-bindings
new file mode 120000
index 000000000..04fdbb3af
--- /dev/null
+++ b/scripts/dtc/include-prefixes/dt-bindings
@@ -0,0 +1 @@
+../../../include/dt-bindings
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/microblaze b/scripts/dtc/include-prefixes/microblaze
new file mode 120000
index 000000000..d9830330a
--- /dev/null
+++ b/scripts/dtc/include-prefixes/microblaze
@@ -0,0 +1 @@
+../../../arch/microblaze/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/mips b/scripts/dtc/include-prefixes/mips
new file mode 120000
index 000000000..ae8d4948d
--- /dev/null
+++ b/scripts/dtc/include-prefixes/mips
@@ -0,0 +1 @@
+../../../arch/mips/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/nios2 b/scripts/dtc/include-prefixes/nios2
new file mode 120000
index 000000000..51772336d
--- /dev/null
+++ b/scripts/dtc/include-prefixes/nios2
@@ -0,0 +1 @@
+../../../arch/nios2/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/openrisc b/scripts/dtc/include-prefixes/openrisc
new file mode 120000
index 000000000..71c3bc75c
--- /dev/null
+++ b/scripts/dtc/include-prefixes/openrisc
@@ -0,0 +1 @@
+../../../arch/openrisc/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/powerpc b/scripts/dtc/include-prefixes/powerpc
new file mode 120000
index 000000000..7cd6ec16e
--- /dev/null
+++ b/scripts/dtc/include-prefixes/powerpc
@@ -0,0 +1 @@
+../../../arch/powerpc/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/riscv b/scripts/dtc/include-prefixes/riscv
new file mode 120000
index 000000000..202509418
--- /dev/null
+++ b/scripts/dtc/include-prefixes/riscv
@@ -0,0 +1 @@
+../../../arch/riscv/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/sh b/scripts/dtc/include-prefixes/sh
new file mode 120000
index 000000000..67d37808c
--- /dev/null
+++ b/scripts/dtc/include-prefixes/sh
@@ -0,0 +1 @@
+../../../arch/sh/boot/dts
\ No newline at end of file
diff --git a/scripts/dtc/include-prefixes/xtensa b/scripts/dtc/include-prefixes/xtensa
new file mode 120000
index 000000000..d1eaf6ec7
--- /dev/null
+++ b/scripts/dtc/include-prefixes/xtensa
@@ -0,0 +1 @@
+../../../arch/xtensa/boot/dts
\ No newline at end of file