s390/mem_detect: use SCLP info for continuous memory detection

When neither SCLP storage info, nor z/VM diag260 "storage configuration"
are available assume a continuous online memory of size specified by
SCLP info.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/arch/s390/boot/mem_detect.c b/arch/s390/boot/mem_detect.c
index 42b0cd23f04a..3becf6bbe4c7 100644
--- a/arch/s390/boot/mem_detect.c
+++ b/arch/s390/boot/mem_detect.c
@@ -184,8 +184,13 @@ void detect_memory(void)
                 return;
         }
 
+        if (max_physmem_end) {
+                add_mem_detect_block(0, max_physmem_end);
+                mem_detect.info_source = MEM_DETECT_SCLP_READ_INFO;
+                return;
+        }
+
         scan_memory(rzm);
         mem_detect.info_source = MEM_DETECT_TPROT_LOOP;
-        if (!max_physmem_end)
-                max_physmem_end = get_mem_detect_end();
+        max_physmem_end = get_mem_detect_end();
 }