powerpc/numa: NUMA topology support for PowerNV

This patch adds support for numa topology on powernv platforms running
OPAL formware. It checks for the type of platform at run time and
sets the affinity form correctly so that NUMA topology can be discovered
correctly.

Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 17 insertions, 7 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index c7dd4dec4df8..b22a83a91cb8 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -315,7 +315,10 @@ static int __init find_min_common_depth(void)
         struct device_node *root;
         const char *vec5;
 
-        root = of_find_node_by_path("/rtas");
+        if (firmware_has_feature(FW_FEATURE_OPAL))
+                root = of_find_node_by_path("/ibm,opal");
+        else
+                root = of_find_node_by_path("/rtas");
         if (!root)
                 root = of_find_node_by_path("/");
 
@@ -344,12 +347,19 @@ static int __init find_min_common_depth(void)
 
 #define VEC5_AFFINITY_BYTE      5
 #define VEC5_AFFINITY           0x80
-        chosen = of_find_node_by_path("/chosen");
-        if (chosen) {
-                vec5 = of_get_property(chosen, "ibm,architecture-vec-5", NULL);
-                if (vec5 && (vec5[VEC5_AFFINITY_BYTE] & VEC5_AFFINITY)) {
-                        dbg("Using form 1 affinity\n");
-                        form1_affinity = 1;
+
+        if (firmware_has_feature(FW_FEATURE_OPAL))
+                form1_affinity = 1;
+        else {
+                chosen = of_find_node_by_path("/chosen");
+                if (chosen) {
+                        vec5 = of_get_property(chosen,
+                                               "ibm,architecture-vec-5", NULL);
+                        if (vec5 && (vec5[VEC5_AFFINITY_BYTE] &
+                                                        VEC5_AFFINITY)) {
+                                dbg("Using form 1 affinity\n");
+                                form1_affinity = 1;
+                        }
                 }
         }