xtensa: don't make bootmem bitmap larger than required

If min_low_pfn is non-zero, the bitmap reserved for bootmem is bigger
than needed.  The number of pages bootmem has to maintain is the range
from min_low_pfn to max_low_pfn.

For now it has only been a theoretical mistake, min_low_pfn was always
zero.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
index 55b043a5918..a534d52a57b 100644
--- a/arch/xtensa/mm/init.c
+++ b/arch/xtensa/mm/init.c
@@ -130,7 +130,8 @@ void __init bootmem_init(void)
 
         /* Find an area to use for the bootmem bitmap. */
 
-        bootmap_size = bootmem_bootmap_pages(max_low_pfn) << PAGE_SHIFT;
+        bootmap_size = bootmem_bootmap_pages(max_low_pfn - min_low_pfn);
+        bootmap_size <<= PAGE_SHIFT;
         bootmap_start = ~0;
 
         for (i=0; i<sysmem.nr_banks; i++)