x86-64, NUMA: Implement generic node distance handling

Node distance either used direct node comparison, ACPI PXM comparison
or ACPI SLIT table lookup.  This patch implements generic node
distance handling.  NUMA init methods can call numa_set_distance() to
set distance between nodes and the common __node_distance()
implementation will report the set distance.

Due to the way NUMA emulation is implemented, the generic node
distance handling is used only when emulation is not used.  Later
patches will update NUMA emulation to use the generic distance
mechanism.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Shaohui Zheng <shaohui.zheng@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@linux.intel.com>

3 files changed, 3 insertions, 1 deletions

diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index cfa3d5c3144a..9c9fe1b0bc4e 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -190,6 +190,7 @@ extern int x86_acpi_numa_init(void);
 #ifdef CONFIG_NUMA_EMU
 extern void acpi_fake_nodes(const struct bootnode *fake_nodes,
                                    int num_nodes);
+extern int acpi_emu_node_distance(int a, int b);
 #endif
 #endif /* CONFIG_ACPI_NUMA */
 
diff --git a/arch/x86/include/asm/numa_64.h b/arch/x86/include/asm/numa_64.h
index f42710bd3e73..5361c5947986 100644
--- a/arch/x86/include/asm/numa_64.h
+++ b/arch/x86/include/asm/numa_64.h
@@ -28,6 +28,7 @@ extern nodemask_t numa_nodes_parsed __initdata;
 
 extern int __cpuinit numa_cpu_node(int cpu);
 extern int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+extern void __init numa_set_distance(int from, int to, int distance);
 
 #ifdef CONFIG_NUMA_EMU
 #define FAKE_NODE_MIN_SIZE      ((u64)32 << 20)
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index b101c17861f5..910a7084f7f2 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -138,7 +138,7 @@ extern unsigned long node_remap_size[];
         .balance_interval       = 1,                                    \
 }
 
-#ifdef CONFIG_X86_64_ACPI_NUMA
+#ifdef CONFIG_X86_64
 extern int __node_distance(int, int);
 #define node_distance(a, b) __node_distance(a, b)
 #endif