memblock: Add "start" argument to memblock_find_base()

To constraint the search of a region between two boundaries,
which will be used by the new NUMA aware allocator among others.

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

diff --git a/mm/memblock.c b/mm/memblock.c
index 8715f09..468ff43 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -117,19 +117,18 @@ static phys_addr_t __init memblock_find_region(phys_addr_t start, phys_addr_t en
        return MEMBLOCK_ERROR;
 }
 
-static phys_addr_t __init memblock_find_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 start, phys_addr_t end)
 {
        long i;
-       phys_addr_t base = 0;
-       phys_addr_t res_base;
 
        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;
+       if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
+               end = memblock.current_limit;
 
        /* We do a top-down search, this tends to limit memory
         * fragmentation by keeping early boot allocs near the
@@ -138,13 +137,19 @@ static phys_addr_t __init memblock_find_base(phys_addr_t size, phys_addr_t align
        for (i = memblock.memory.cnt - 1; i >= 0; i--) {
                phys_addr_t memblockbase = memblock.memory.regions[i].base;
                phys_addr_t memblocksize = memblock.memory.regions[i].size;
+               phys_addr_t bottom, top, found;
 
                if (memblocksize < size)
                        continue;
-               base = min(memblockbase + memblocksize, max_addr);
-               res_base = memblock_find_region(memblockbase, base, size, align);
-               if (res_base != MEMBLOCK_ERROR)
-                       return res_base;
+               if ((memblockbase + memblocksize) <= start)
+                       break;
+               bottom = max(memblockbase, start);
+               top = min(memblockbase + memblocksize, end);
+               if (bottom >= top)
+                       continue;
+               found = memblock_find_region(bottom, top, size, align);
+               if (found != MEMBLOCK_ERROR)
+                       return found;
        }
        return MEMBLOCK_ERROR;
 }
@@ -204,7 +209,7 @@ static int memblock_double_array(struct memblock_type *type)
                new_array = kmalloc(new_size, GFP_KERNEL);
                addr = new_array == NULL ? MEMBLOCK_ERROR : __pa(new_array);
        } else
-               addr = memblock_find_base(new_size, sizeof(phys_addr_t), MEMBLOCK_ALLOC_ACCESSIBLE);
+               addr = memblock_find_base(new_size, sizeof(phys_addr_t), 0, MEMBLOCK_ALLOC_ACCESSIBLE);
        if (addr == MEMBLOCK_ERROR) {
                pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
                       memblock_type_name(type), type->max, type->max * 2);
@@ -416,7 +421,7 @@ phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, ph
         */
        size = memblock_align_up(size, align);
 
-       found = memblock_find_base(size, align, max_addr);
+       found = memblock_find_base(size, align, 0, max_addr);
        if (found != MEMBLOCK_ERROR &&
            memblock_add_region(&memblock.reserved, found, size) >= 0)
                return found;