memblock: split memblock_find_base() out of __memblock_alloc_base()

This will be used by the array resize code and might prove useful
to some arch code as well at which point it can be made non-static.

Also add comment as to why aligning size is important

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

v2. Fix loss of size alignment
v3. Fix result code

1 files changed, 38 insertions, 20 deletions

diff --git a/mm/memblock.c b/mm/memblock.c
index ae856d4e25a3..b775fca4fba5 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -345,12 +345,15 @@ phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int n
 
         BUG_ON(0 == size);
 
+        /* We align the size to limit fragmentation. Without this, a lot of
+         * small allocs quickly eat up the whole reserve array on sparc
+         */
+        size = memblock_align_up(size, align);
+
         /* We do a bottom-up search for a region with the right
          * nid since that's easier considering how memblock_nid_range()
          * works
          */
-        size = memblock_align_up(size, align);
-
         for (i = 0; i < mem->cnt; i++) {
                 phys_addr_t ret = memblock_alloc_nid_region(&mem->regions[i],
                                                size, align, nid);
@@ -366,20 +369,7 @@ phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
         return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
 }
 
-phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
-{
-        phys_addr_t alloc;
-
-        alloc = __memblock_alloc_base(size, align, max_addr);
-
-        if (alloc == 0)
-                panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
-                      (unsigned long long) size, (unsigned long long) max_addr);
-
-        return alloc;
-}
-
-phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+static phys_addr_t __init memblock_find_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
 {
         long i;
         phys_addr_t base = 0;
@@ -387,8 +377,6 @@ phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, ph
 
         BUG_ON(0 == size);
 
-        size = memblock_align_up(size, align);
-
         /* Pump up max_addr */
         if (max_addr == MEMBLOCK_ALLOC_ACCESSIBLE)
                 max_addr = memblock.current_limit;
@@ -405,13 +393,43 @@ phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, ph
                         continue;
                 base = min(memblockbase + memblocksize, max_addr);
                 res_base = memblock_find_region(memblockbase, base, size, align);
-                if (res_base != MEMBLOCK_ERROR &&
-                    memblock_add_region(&memblock.reserved, res_base, size) >= 0)
+                if (res_base != MEMBLOCK_ERROR)
                         return res_base;
         }
+        return MEMBLOCK_ERROR;
+}
+
+phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+{       
+        phys_addr_t found;
+
+        /* We align the size to limit fragmentation. Without this, a lot of
+         * small allocs quickly eat up the whole reserve array on sparc
+         */
+        size = memblock_align_up(size, align);
+
+        found = memblock_find_base(size, align, max_addr);
+        if (found != MEMBLOCK_ERROR &&
+            memblock_add_region(&memblock.reserved, found, size) >= 0)
+                return found;
+
         return 0;
 }
 
+phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
+{
+        phys_addr_t alloc;
+
+        alloc = __memblock_alloc_base(size, align, max_addr);
+
+        if (alloc == 0)
+                panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
+                      (unsigned long long) size, (unsigned long long) max_addr);
+
+        return alloc;
+}
+
+
 /* You must call memblock_analyze() before this. */
 phys_addr_t __init memblock_phys_mem_size(void)
 {