memblock: Implement memblock_is_memory and memblock_is_region_memory

To make it fast, we steal ARM's binary search for memblock_is_memory()
and we use that to also the replace existing implementation of
memblock_is_reserved().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 4b6931327b22ce91b76e0eb3d49ac98716d419e5..47bceb187058342f6f2e8ed4e26d71745890fc8c 100644 (file)
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -56,6 +56,8 @@ extern u64 __init __memblock_alloc_base(u64 size,
 extern u64 __init memblock_phys_mem_size(void);
 extern u64 memblock_end_of_DRAM(void);
 extern void __init memblock_enforce_memory_limit(u64 memory_limit);
+extern int memblock_is_memory(u64 addr);
+extern int memblock_is_region_memory(u64 base, u64 size);
 extern int __init memblock_is_reserved(u64 addr);
 extern int memblock_is_region_reserved(u64 base, u64 size);
 extern int memblock_find(struct memblock_region *res);

diff --git a/mm/memblock.c b/mm/memblock.c
index 6f407ccf604e762fc54115eae2b1f71b389a9557..aa88c62bce7f6e8b98124c79c0caf79b7350e1ab 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -487,17 +487,43 @@ void __init memblock_enforce_memory_limit(u64 memory_limit)
        }
 }
 
+static int memblock_search(struct memblock_type *type, u64 addr)
+{
+       unsigned int left = 0, right = type->cnt;
+
+       do {
+               unsigned int mid = (right + left) / 2;
+
+               if (addr < type->regions[mid].base)
+                       right = mid;
+               else if (addr >= (type->regions[mid].base +
+                                 type->regions[mid].size))
+                       left = mid + 1;
+               else
+                       return mid;
+       } while (left < right);
+       return -1;
+}
+
 int __init memblock_is_reserved(u64 addr)
 {
-       int i;
+       return memblock_search(&memblock.reserved, addr) != -1;
+}
 
-       for (i = 0; i < memblock.reserved.cnt; i++) {
-               u64 upper = memblock.reserved.regions[i].base +
-                       memblock.reserved.regions[i].size - 1;
-               if ((addr >= memblock.reserved.regions[i].base) && (addr <= upper))
-                       return 1;
-       }
-       return 0;
+int memblock_is_memory(u64 addr)
+{
+       return memblock_search(&memblock.memory, addr) != -1;
+}
+
+int memblock_is_region_memory(u64 base, u64 size)
+{
+       int idx = memblock_search(&memblock.reserved, base);
+
+       if (idx == -1)
+               return 0;
+       return memblock.reserved.regions[idx].base <= base &&
+               (memblock.reserved.regions[idx].base +
+                memblock.reserved.regions[idx].size) >= (base + size);
 }
 
 int memblock_is_region_reserved(u64 base, u64 size)