From: Vishal Badole <Vishal.Badole@amd.com>
To: <tglx@kernel.org>, <mingo@redhat.com>, <bp@alien8.de>,
<dave.hansen@linux.intel.com>, <x86@kernel.org>, <hpa@zytor.com>,
<rafael@kernel.org>, <lenb@kernel.org>
Cc: <linux-kernel@vger.kernel.org>, <linux-acpi@vger.kernel.org>,
<peterz@infradead.org>, <tony.luck@intel.com>,
<chang.seok.bae@intel.com>, <wei.w.wang@hotmail.com>,
Vishal Badole <Vishal.Badole@amd.com>
Subject: [PATCH 1/2] x86/topology: Name the AMD core-type values
Date: Mon, 29 Jun 2026 15:13:48 +0530 [thread overview]
Message-ID: <20260629094349.533301-2-Vishal.Badole@amd.com> (raw)
In-Reply-To: <20260629094349.533301-1-Vishal.Badole@amd.com>
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@alien8.de>
Signed-off-by: Vishal Badole <Vishal.Badole@amd.com>
---
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 0ba9bdb99871..9658b5676ce6 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -120,6 +120,12 @@ enum x86_topology_cpu_type {
TOPO_CPU_TYPE_UNKNOWN,
};
+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 cf7513416b70..e1cc25a115ca 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;
}
}
--
2.34.1
next prev parent reply other threads:[~2026-06-29 9:45 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-29 9:43 [PATCH 0/2] x86/topology: Add support for Low Power cpu_type Vishal Badole
2026-06-29 9:43 ` Vishal Badole [this message]
2026-07-02 0:27 ` [PATCH 1/2] x86/topology: Name the AMD core-type values Borislav Petkov
2026-07-02 22:06 ` Thomas Gleixner
2026-07-02 23:03 ` Borislav Petkov
2026-07-03 19:32 ` Borislav Petkov
2026-07-03 19:39 ` Thomas Gleixner
2026-06-29 9:43 ` [PATCH 2/2] x86/topology: Add TOPO_CPU_TYPE_LOW_POWER Vishal Badole
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