From c34a69059d7876e0793eb410deedfb08ccb22b02 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 10 May 2016 12:10:22 +0200 Subject: s390/vmem: fix identity mapping The identity mapping is suboptimal for the last 2GB frame. The mapping will be established with a mix of 4KB and 1MB mappings instead of a single 2GB mapping. This happens because of a off-by-one bug introduced with commit 50be63450728 ("s390/mm: Convert bootmem to memblock"). Currently the identity mapping looks like this: 0x0000000080000000-0x0000000180000000 4G PUD RW 0x0000000180000000-0x00000001fff00000 2047M PMD RW 0x00000001fff00000-0x0000000200000000 1M PTE RW With the bug fixed it looks like this: 0x0000000080000000-0x0000000200000000 6G PUD RW Fixes: 50be63450728 ("s390/mm: Convert bootmem to memblock") Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/mm/vmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/s390/mm') diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index d27fccbad7c1..f7ad6cd38e3e 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -370,7 +370,7 @@ void __init vmem_map_init(void) ro_end = (unsigned long)&_eshared & PAGE_MASK; for_each_memblock(memory, reg) { start = reg->base; - end = reg->base + reg->size - 1; + end = reg->base + reg->size; if (start >= ro_end || end <= ro_start) vmem_add_mem(start, end - start, 0); else if (start >= ro_start && end <= ro_end) -- cgit v1.2.1