[POWERPC] Provide walk_memory_resource() for powerpc

Provide walk_memory_resource() for 64-bit powerpc.  PowerPC maintains
logical memory region mapping in the lmb.memory structure.  Walk
through these structures and do the callbacks for the contiguous
chunks.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/lib/lmb.c b/lib/lmb.c
index 5b2a739bc3d5..83287d3869a3 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -474,3 +474,36 @@ int __init lmb_is_reserved(u64 addr)
         }
         return 0;
 }
+
+/*
+ * Given a <base, len>, find which memory regions belong to this range.
+ * Adjust the request and return a contiguous chunk.
+ */
+int lmb_find(struct lmb_property *res)
+{
+        int i;
+        u64 rstart, rend;
+
+        rstart = res->base;
+        rend = rstart + res->size - 1;
+
+        for (i = 0; i < lmb.memory.cnt; i++) {
+                u64 start = lmb.memory.region[i].base;
+                u64 end = start + lmb.memory.region[i].size - 1;
+
+                if (start > rend)
+                        return -1;
+
+                if ((end >= rstart) && (start < rend)) {
+                        /* adjust the request */
+                        if (rstart < start)
+                                rstart = start;
+                        if (rend > end)
+                                rend = end;
+                        res->base = rstart;
+                        res->size = rend - rstart + 1;
+                        return 0;
+                }
+        }
+        return -1;
+}