s390/mm: fix vmemmap size calculation

The size of the vmemmap must be a multiple of PAGES_PER_SECTION, since the
common code always initializes the vmemmap in such pieces.
So we must round up in order to not have a too small vmemmap.

Fixes an IPL crash on 31 bit with more than 1920MB.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index a5360de..2926885 100644 (file)
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -571,6 +571,8 @@ static void __init setup_memory_end(void)
 
        /* Split remaining virtual space between 1:1 mapping & vmemmap array */
        tmp = VMALLOC_START / (PAGE_SIZE + sizeof(struct page));
+       /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
+       tmp = SECTION_ALIGN_UP(tmp);
        tmp = VMALLOC_START - tmp * sizeof(struct page);
        tmp &= ~((vmax >> 11) - 1);     /* align to page table level */
        tmp = min(tmp, 1UL << MAX_PHYSMEM_BITS);