[PATCH v2 3/3] x86/cpu/topology: Check for X86_FEATURE_XTOPOLOGY instead of passing has_topoext
From: K Prateek Nayak
Date: Fri Jul 25 2025 - 07:07:51 EST
cpu_parse_topology_ext() sets X86_FEATURE_XTOPOLOGY before returning
true if any of the XTOPOLOGY leaf could be parsed successfully.
Instead of storing and passing around this return value using
"has_topoext" in parse_topology_amd(), check for X86_FEATURE_XTOPOLOGY
instead in parse_8000_001e() to simplify the flow.
No functional changes intended.
Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
Changelog v1..v2:
o New patch.
---
arch/x86/kernel/cpu/topology_amd.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/cpu/topology_amd.c b/arch/x86/kernel/cpu/topology_amd.c
index b392d91c6df4..1b4f178edd72 100644
--- a/arch/x86/kernel/cpu/topology_amd.c
+++ b/arch/x86/kernel/cpu/topology_amd.c
@@ -59,7 +59,7 @@ static void store_node(struct topo_scan *tscan, u16 nr_nodes, u16 node_id)
tscan->amd_node_id = node_id;
}
-static bool parse_8000_001e(struct topo_scan *tscan, bool has_topoext)
+static bool parse_8000_001e(struct topo_scan *tscan)
{
struct {
// eax
@@ -81,7 +81,7 @@ static bool parse_8000_001e(struct topo_scan *tscan, bool has_topoext)
cpuid_leaf(0x8000001e, &leaf);
- if (!has_topoext) {
+ if (!boot_cpu_has(X86_FEATURE_XTOPOLOGY)) {
/*
* Prefer initial_apicid parsed from XTOPOLOGY leaf
* 0x8000026 or 0xb if available. Otherwise prefer the
@@ -178,6 +178,9 @@ static void topoext_fixup(struct topo_scan *tscan)
static void parse_topology_amd(struct topo_scan *tscan)
{
+ if (cpu_feature_enabled(X86_FEATURE_AMD_HTR_CORES))
+ tscan->c->topo.cpu_type = cpuid_ebx(0x80000026);
+
/*
* Try to get SMT, CORE, TILE, and DIE shifts from extended
* CPUID leaf 0x8000_0026 on supported processors first. If
@@ -185,16 +188,11 @@ static void parse_topology_amd(struct topo_scan *tscan)
* get SMT and CORE shift from leaf 0xb first, then try to
* get the CORE shift from leaf 0x8000_0008.
*/
- bool has_topoext = 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 (!cpu_parse_topology_ext(tscan) && !parse_8000_0008(tscan))
return;
/* Prefer leaf 0x8000001e if available */
- if (parse_8000_001e(tscan, has_topoext))
+ if (parse_8000_001e(tscan))
return;
/* Try the NODEID MSR */
--
2.34.1