powerpc/numa: Use ibm,architecture-vec-5 to detect form 1 affinity

I've been told that the architected way to determine we are in form 1
affinity mode is by reading the ibm,architecture-vec-5 property which
mirrors the layout of the fifth vector of the ibm,client-architecture
structure.

Eventually we may want to parse the ibm,architecture-vec-5 and create
FW_FEATURE_* bits.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 12 insertions, 8 deletions

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index aace5e5dfa0a..80d110635d24 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -271,7 +271,8 @@ static int __init find_min_common_depth(void)
         const unsigned int *ref_points;
         struct device_node *rtas_root;
         unsigned int len;
-        struct device_node *options;
+        struct device_node *chosen;
+        const char *vec5;
 
         rtas_root = of_find_node_by_path("/rtas");
 
@@ -289,14 +290,17 @@ static int __init find_min_common_depth(void)
                         "ibm,associativity-reference-points", &len);
 
         /*
-         * For type 1 affinity information we want the first field
+         * For form 1 affinity information we want the first field
          */
-        options = of_find_node_by_path("/options");
-        if (options) {
-                const char *str;
-                str = of_get_property(options, "ibm,associativity-form", NULL);
-                if (str && !strcmp(str, "1"))
-                        index = 0;
+#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");
+                        index = 0;
+                }
         }
 
         if ((len >= 2 * sizeof(unsigned int)) && ref_points) {