[PATCH 3/4] x86/cpu/intel: Add function to get name of hybrid CPU types

[Ricardo Neri]

Provided a human-friendly string name for each type of CPU micro-
architecture in Intel hybrid parts. This string is to be used in the
CPU type sysfs interface.

In order to uniquely identify CPUs of the same type, compose the name
string as <cpu_type_name>_<native_model_id_nr>.

Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Len Brown <len.brown@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
Cc: "Ravi V. Shankar" <ravi.v.shankar@xxxxxxxxx>
Cc: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@xxxxxxxxxxxxxxx>
---
 arch/x86/include/asm/intel-family.h |  4 ++++
 arch/x86/kernel/cpu/cpu.h           |  3 +++
 arch/x86/kernel/cpu/intel.c         | 23 +++++++++++++++++++++++
 3 files changed, 30 insertions(+)

diff --git a/arch/x86/include/asm/intel-family.h b/arch/x86/include/asm/intel-family.h
index 5e658ba2654a..4ec2272e0049 100644
--- a/arch/x86/include/asm/intel-family.h
+++ b/arch/x86/include/asm/intel-family.h
@@ -133,4 +133,8 @@
 /* Family 5 */
 #define INTEL_FAM5_QUARK_X1000		0x09 /* Quark X1000 SoC */
 
+/* Types of CPUs in hybrid parts. */
+#define INTEL_HYBRID_TYPE_ATOM		0x20
+#define INTEL_HYBRID_TYPE_CORE		0x40
+
 #endif /* _ASM_X86_INTEL_FAMILY_H */
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index 9d033693519a..b4474238e1f3 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -56,8 +56,11 @@ extern __ro_after_init enum tsx_ctrl_states tsx_ctrl_state;
 extern void __init tsx_init(void);
 extern void tsx_enable(void);
 extern void tsx_disable(void);
+extern const char *intel_get_hybrid_cpu_type_name(u32 cpu_type);
 #else
 static inline void tsx_init(void) { }
+static inline const char *intel_get_hybrid_cpu_type_name(u32 cpu_type)
+{ return NULL; }
 #endif /* CONFIG_CPU_SUP_INTEL */
 
 extern void get_cpu_cap(struct cpuinfo_x86 *c);
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 59a1e3ce3f14..e1dee382cf98 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -1191,3 +1191,26 @@ void __init cpu_set_core_cap_bits(struct cpuinfo_x86 *c)
 	cpu_model_supports_sld = true;
 	split_lock_setup();
 }
+
+static char hybrid_name[64];
+
+const char *intel_get_hybrid_cpu_type_name(u32 cpu_type)
+{
+	u32 native_model_id = cpu_type & X86_HYBRID_CPU_NATIVE_MODEL_ID_MASK;
+	u8 type = cpu_type >> X86_HYBRID_CPU_TYPE_ID_SHIFT;
+
+	switch (type) {
+	case INTEL_HYBRID_TYPE_ATOM:
+		snprintf(hybrid_name, sizeof(hybrid_name), "intel_atom_%u",
+			 native_model_id);
+		break;
+	case INTEL_HYBRID_TYPE_CORE:
+		snprintf(hybrid_name, sizeof(hybrid_name), "intel_core_%u",
+			 native_model_id);
+		break;
+	default:
+		return NULL;
+	}
+
+	return hybrid_name;
+}
-- 
2.17.1