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

5 files changed, 150 insertions, 0 deletions

diff --git a/Documentation/features/time/arch-tick-broadcast/arch-support.txt b/Documentation/features/time/arch-tick-broadcast/arch-support.txt
new file mode 100644
index 000000000..ccba965e8
--- /dev/null
+++ b/Documentation/features/time/arch-tick-broadcast/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          arch-tick-broadcast
+#         Kconfig:       ARCH_HAS_TICK_BROADCAST
+#         description:   arch provides tick_broadcast()
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: | TODO |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: | TODO |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: | TODO |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: | TODO |
+    |          sh: |  ok  |
+    |       sparc: | TODO |
+    |          um: | TODO |
+    |         x86: | TODO |
+    |      xtensa: | TODO |
+    -----------------------
diff --git a/Documentation/features/time/clockevents/arch-support.txt b/Documentation/features/time/clockevents/arch-support.txt
new file mode 100644
index 000000000..d6100b226
--- /dev/null
+++ b/Documentation/features/time/clockevents/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          clockevents
+#         Kconfig:       !LEGACY_TIMER_TICK
+#         description:   arch support generic clock events
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: |  ok  |
+    |         arc: |  ok  |
+    |         arm: | TODO |
+    |       arm64: |  ok  |
+    |        csky: |  ok  |
+    |     hexagon: |  ok  |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: |  ok  |
+    |        mips: |  ok  |
+    |       nios2: |  ok  |
+    |    openrisc: |  ok  |
+    |      parisc: |  ok  |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: |  ok  |
+    |          sh: |  ok  |
+    |       sparc: |  ok  |
+    |          um: |  ok  |
+    |         x86: |  ok  |
+    |      xtensa: |  ok  |
+    -----------------------
diff --git a/Documentation/features/time/context-tracking/arch-support.txt b/Documentation/features/time/context-tracking/arch-support.txt
new file mode 100644
index 000000000..891be9f61
--- /dev/null
+++ b/Documentation/features/time/context-tracking/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          user-context-tracking
+#         Kconfig:       HAVE_CONTEXT_TRACKING_USER
+#         description:   arch supports user context tracking for NO_HZ_FULL
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: | TODO |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: |  ok  |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: | TODO |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: | TODO |
+    |          sh: | TODO |
+    |       sparc: |  ok  |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: |  ok  |
+    -----------------------
diff --git a/Documentation/features/time/irq-time-acct/arch-support.txt b/Documentation/features/time/irq-time-acct/arch-support.txt
new file mode 100644
index 000000000..3d10075a8
--- /dev/null
+++ b/Documentation/features/time/irq-time-acct/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          irq-time-acct
+#         Kconfig:       HAVE_IRQ_TIME_ACCOUNTING
+#         description:   arch supports precise IRQ time accounting
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: |  ..  |
+    |         arc: | TODO |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: | TODO |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: |  ..  |
+    |     powerpc: |  ok  |
+    |       riscv: |  ok  |
+    |        s390: |  ..  |
+    |          sh: | TODO |
+    |       sparc: |  ..  |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: |  ok  |
+    -----------------------
diff --git a/Documentation/features/time/virt-cpuacct/arch-support.txt b/Documentation/features/time/virt-cpuacct/arch-support.txt
new file mode 100644
index 000000000..21f11d47e
--- /dev/null
+++ b/Documentation/features/time/virt-cpuacct/arch-support.txt
@@ -0,0 +1,30 @@
+#
+# Feature name:          virt-cpuacct
+#         Kconfig:       HAVE_VIRT_CPU_ACCOUNTING
+#         description:   arch supports precise virtual CPU time accounting
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: |  ok  |
+    |         arc: | TODO |
+    |         arm: |  ok  |
+    |       arm64: |  ok  |
+    |        csky: |  ok  |
+    |     hexagon: | TODO |
+    |   loongarch: |  ok  |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: |  ok  |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: |  ok  |
+    |     powerpc: |  ok  |
+    |       riscv: | TODO |
+    |        s390: |  ok  |
+    |          sh: | TODO |
+    |       sparc: |  ok  |
+    |          um: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: |  ok  |
+    -----------------------