[RFC][PATCH 2/6] x86/topo: Add TOPO_NUMA_DOMAIN

[Peter Zijlstra]

Use the SRAT data to add an extra NUMA domain. Since the SLIT table is
a matrix, the SRAT proximity domain 'must' be a dense set and will not
exceed MAX_LOCAL_APIC.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
 arch/x86/include/asm/topology.h |    3 +++
 arch/x86/kernel/cpu/topology.c  |    9 +++++++++
 2 files changed, 12 insertions(+)

--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -111,6 +111,9 @@ enum x86_topology_domains {
 	TOPO_DIE_DOMAIN,
 	TOPO_DIEGRP_DOMAIN,
 	TOPO_PKG_DOMAIN,
+#ifdef CONFIG_NUMA
+	TOPO_NUMA_DOMAIN,
+#endif
 	TOPO_MAX_DOMAIN,
 };
 
--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -31,6 +31,7 @@
 #include <asm/mpspec.h>
 #include <asm/msr.h>
 #include <asm/smp.h>
+#include <asm/numa.h>
 
 #include "cpu.h"
 
@@ -88,6 +89,14 @@ static inline u32 topo_apicid(u32 apicid
 {
 	if (dom == TOPO_SMT_DOMAIN)
 		return apicid;
+#ifdef CONFIG_NUMA
+	if (dom == TOPO_NUMA_DOMAIN) {
+		int nid = __apicid_to_phys_node[apicid];
+		if (nid == NUMA_NO_NODE)
+			nid = 0;
+		return nid;
+	}
+#endif
 	return apicid & (UINT_MAX << x86_topo_system.dom_shifts[dom - 1]);
 }