1 files changed, 67 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/topology.h b/arch/x86/kernel/cpu/topology.h
new file mode 100644
index 0000000000..37326297f8
--- /dev/null
+++ b/arch/x86/kernel/cpu/topology.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_X86_TOPOLOGY_H
+#define ARCH_X86_TOPOLOGY_H
+
+struct topo_scan {
+	struct cpuinfo_x86	*c;
+	unsigned int		dom_shifts[TOPO_MAX_DOMAIN];
+	unsigned int		dom_ncpus[TOPO_MAX_DOMAIN];
+
+	/* Legacy CPUID[1]:EBX[23:16] number of logical processors */
+	unsigned int		ebx1_nproc_shift;
+
+	/* AMD specific node ID which cannot be mapped into APIC space. */
+	u16			amd_nodes_per_pkg;
+	u16			amd_node_id;
+};
+
+void cpu_init_topology(struct cpuinfo_x86 *c);
+void cpu_parse_topology(struct cpuinfo_x86 *c);
+void topology_set_dom(struct topo_scan *tscan, enum x86_topology_domains dom,
+		      unsigned int shift, unsigned int ncpus);
+bool cpu_parse_topology_ext(struct topo_scan *tscan);
+void cpu_parse_topology_amd(struct topo_scan *tscan);
+void cpu_topology_fixup_amd(struct topo_scan *tscan);
+
+static inline u32 topo_shift_apicid(u32 apicid, enum x86_topology_domains dom)
+{
+	if (dom == TOPO_SMT_DOMAIN)
+		return apicid;
+	return apicid >> x86_topo_system.dom_shifts[dom - 1];
+}
+
+static inline u32 topo_relative_domain_id(u32 apicid, enum x86_topology_domains dom)
+{
+	if (dom != TOPO_SMT_DOMAIN)
+		apicid >>= x86_topo_system.dom_shifts[dom - 1];
+	return apicid & (x86_topo_system.dom_size[dom] - 1);
+}
+
+static inline u32 topo_domain_mask(enum x86_topology_domains dom)
+{
+	return (1U << x86_topo_system.dom_shifts[dom]) - 1;
+}
+
+/*
+ * Update a domain level after the fact without propagating. Used to fixup
+ * broken CPUID enumerations.
+ */
+static inline void topology_update_dom(struct topo_scan *tscan, enum x86_topology_domains dom,
+				       unsigned int shift, unsigned int ncpus)
+{
+	tscan->dom_shifts[dom] = shift;
+	tscan->dom_ncpus[dom] = ncpus;
+}
+
+#ifdef CONFIG_X86_LOCAL_APIC
+unsigned int topology_unit_count(u32 apicid, enum x86_topology_domains which_units,
+				 enum x86_topology_domains at_level);
+#else
+static inline unsigned int topology_unit_count(u32 apicid, enum x86_topology_domains which_units,
+					       enum x86_topology_domains at_level)
+{
+	return 1;
+}
+#endif
+
+#endif /* ARCH_X86_TOPOLOGY_H */