Merge tag 'x86-urgent-2025-09-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Fix a CPU topology parsing bug on AMD guests, and address
  a lockdep warning in the resctrl filesystem"

* tag 'x86-urgent-2025-09-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  fs/resctrl: Eliminate false positive lockdep warning when reading SNC counters
  x86/cpu/topology: Always try cpu_parse_topology_ext() on AMD/Hygon

1 files changed, 14 insertions, 11 deletions

diff --git a/arch/x86/kernel/cpu/topology_amd.c b/arch/x86/kernel/cpu/topology_amd.c
index 827dd0dbb6e9..c79ebbb639cb 100644
--- a/arch/x86/kernel/cpu/topology_amd.c
+++ b/arch/x86/kernel/cpu/topology_amd.c
@@ -175,27 +175,30 @@ static void topoext_fixup(struct topo_scan *tscan)
 
 static void parse_topology_amd(struct topo_scan *tscan)
 {
-	bool has_topoext = false;
-
 	/*
-	 * If the extended topology leaf 0x8000_001e is available
-	 * try to get SMT, CORE, TILE, and DIE shifts from extended
+	 * Try to get SMT, CORE, TILE, and DIE shifts from extended
 	 * CPUID leaf 0x8000_0026 on supported processors first. If
 	 * extended CPUID leaf 0x8000_0026 is not supported, try to
-	 * get SMT and CORE shift from leaf 0xb first, then try to
-	 * get the CORE shift from leaf 0x8000_0008.
+	 * get SMT and CORE shift from leaf 0xb. If either leaf is
+	 * available, cpu_parse_topology_ext() will return true.
 	 */
-	if (cpu_feature_enabled(X86_FEATURE_TOPOEXT))
-		has_topoext = cpu_parse_topology_ext(tscan);
+	bool has_xtopology = cpu_parse_topology_ext(tscan);
 
 	if (cpu_feature_enabled(X86_FEATURE_AMD_HTR_CORES))
 		tscan->c->topo.cpu_type = cpuid_ebx(0x80000026);
 
-	if (!has_topoext && !parse_8000_0008(tscan))
+	/*
+	 * If XTOPOLOGY leaves (0x26/0xb) are not available, try to
+	 * get the CORE shift from leaf 0x8000_0008 first.
+	 */
+	if (!has_xtopology && !parse_8000_0008(tscan))
 		return;
 
-	/* Prefer leaf 0x8000001e if available */
-	if (parse_8000_001e(tscan, has_topoext))
+	/*
+	 * Prefer leaf 0x8000001e if available to get the SMT shift and
+	 * the initial APIC ID if XTOPOLOGY leaves are not available.
+	 */
+	if (parse_8000_001e(tscan, has_xtopology))
 		return;
 
 	/* Try the NODEID MSR */