[tip: x86/cpu] x86/topology: Name the AMD core-type values

[tip-bot2 for Vishal Badole]

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     bdb1b1f03b9b1cc1cde7d54f8b5b2f9a6bdda782
Gitweb:        https://git.kernel.org/tip/bdb1b1f03b9b1cc1cde7d54f8b5b2f9a6bdda782
Author:        Vishal Badole <Vishal.Badole@xxxxxxx>
AuthorDate:    Tue, 21 Jul 2026 21:15:13 +05:30
Committer:     Borislav Petkov (AMD) <bp@xxxxxxxxx>
CommitterDate: Thu, 23 Jul 2026 14:23:27 -07:00

x86/topology: Name the AMD core-type values

Replace the bare 0/1 in get_topology_cpu_type() with named constants that
mirror what the AMD APM publishes for CPUID Fn0x80000026 EBX[31:28] (Extended
CPU Topology, Core Type):

  0 - Performance core
  1 - Efficient core
  2 - Low-power core (used by a follow-up)

No functional change.

Suggested-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Signed-off-by: Vishal Badole <Vishal.Badole@xxxxxxx>
Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://patch.msgid.link/20260721154514.2506972-3-Vishal.Badole@xxxxxxx
---
 arch/x86/include/asm/topology.h       | 6 ++++++
 arch/x86/kernel/cpu/topology_common.c | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index ef76ba6..1825691 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -114,6 +114,12 @@ enum x86_topology_domains {
 	TOPO_MAX_DOMAIN,
 };
 
+enum amd_cpu_type {
+	AMD_CPU_TYPE_PERFORMANCE	= 0,
+	AMD_CPU_TYPE_EFFICIENCY		= 1,
+	AMD_CPU_TYPE_LOW_POWER		= 2,
+};
+
 struct x86_topology_system {
 	unsigned int	dom_shifts[TOPO_MAX_DOMAIN];
 	unsigned int	dom_size[TOPO_MAX_DOMAIN];
diff --git a/arch/x86/kernel/cpu/topology_common.c b/arch/x86/kernel/cpu/topology_common.c
index b9d025f..71b6c33 100644
--- a/arch/x86/kernel/cpu/topology_common.c
+++ b/arch/x86/kernel/cpu/topology_common.c
@@ -42,8 +42,8 @@ enum x86_topology_cpu_type get_topology_cpu_type(struct cpuinfo_x86 *c)
 	}
 	if (c->x86_vendor == X86_VENDOR_AMD) {
 		switch (c->topo.amd_type) {
-		case 0:	return TOPO_CPU_TYPE_PERFORMANCE;
-		case 1:	return TOPO_CPU_TYPE_EFFICIENCY;
+		case AMD_CPU_TYPE_PERFORMANCE:	return TOPO_CPU_TYPE_PERFORMANCE;
+		case AMD_CPU_TYPE_EFFICIENCY:	return TOPO_CPU_TYPE_EFFICIENCY;
 		}
 	}