4 files changed, 31 insertions, 20 deletions

diff --git a/arch/s390/include/asm/sysinfo.h b/arch/s390/include/asm/sysinfo.h
index 12e5256adca3..04e6e9774708 100644
--- a/arch/s390/include/asm/sysinfo.h
+++ b/arch/s390/include/asm/sysinfo.h
@@ -118,6 +118,8 @@ struct sysinfo_3_2_2 {
 	char reserved_544[3552];
 };
 
+extern int topology_max_mnest;
+
 #define TOPOLOGY_CPU_BITS	64
 #define TOPOLOGY_NR_MAG		6
 
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 1345ba452c83..f4bcdc01bfc8 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -215,26 +215,44 @@ static noinline __init void init_kernel_storage_key(void)
 				     PAGE_DEFAULT_KEY, 0);
 }
 
-static __initdata struct sysinfo_3_2_2 vmms __aligned(PAGE_SIZE);
+static __initdata char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
 
 static noinline __init void detect_machine_type(void)
 {
+	struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
+
 	/* Check current-configuration-level */
 	if ((stsi(NULL, 0, 0, 0) >> 28) <= 2) {
 		S390_lowcore.machine_flags |= MACHINE_FLAG_LPAR;
 		return;
 	}
 	/* Get virtual-machine cpu information. */
-	if (stsi(&vmms, 3, 2, 2) == -ENOSYS || !vmms.count)
+	if (stsi(vmms, 3, 2, 2) == -ENOSYS || !vmms->count)
 		return;
 
 	/* Running under KVM? If not we assume z/VM */
-	if (!memcmp(vmms.vm[0].cpi, "\xd2\xe5\xd4", 3))
+	if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
 		S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
 	else
 		S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 }
 
+static __init void setup_topology(void)
+{
+#ifdef CONFIG_64BIT
+	int max_mnest;
+
+	if (!test_facility(11))
+		return;
+	S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
+	for (max_mnest = 6; max_mnest > 1; max_mnest--) {
+		if (stsi(&sysinfo_page, 15, 1, max_mnest) != -ENOSYS)
+			break;
+	}
+	topology_max_mnest = max_mnest;
+#endif
+}
+
 static void early_pgm_check_handler(void)
 {
 	unsigned long addr;
@@ -364,8 +382,6 @@ static __init void detect_machine_facilities(void)
 		S390_lowcore.machine_flags |= MACHINE_FLAG_IDTE;
 	if (test_facility(8))
 		S390_lowcore.machine_flags |= MACHINE_FLAG_PFMF;
-	if (test_facility(11))
-		S390_lowcore.machine_flags |= MACHINE_FLAG_TOPOLOGY;
 	if (test_facility(27))
 		S390_lowcore.machine_flags |= MACHINE_FLAG_MVCOS;
 	if (test_facility(40))
@@ -467,6 +483,7 @@ void __init startup_init(void)
 	detect_diag44();
 	detect_machine_facilities();
 	setup_hpage();
+	setup_topology();
 	sclp_facilities_detect();
 	detect_memory_layout(memory_chunk);
 #ifdef CONFIG_DYNAMIC_FTRACE
diff --git a/arch/s390/kernel/sysinfo.c b/arch/s390/kernel/sysinfo.c
index 2249b0cf80ef..2af4ee67fe52 100644
--- a/arch/s390/kernel/sysinfo.c
+++ b/arch/s390/kernel/sysinfo.c
@@ -22,6 +22,8 @@
 #include <math-emu/soft-fp.h>
 #include <math-emu/single.h>
 
+int topology_max_mnest;
+
 static inline int stsi_0(void)
 {
 	int rc = stsi(NULL, 0, 0, 0);
@@ -95,15 +97,7 @@ static void stsi_15_1_x(struct seq_file *m, struct sysinfo_15_1_x *info)
 	seq_putc(m, '\n');
 	if (!MACHINE_HAS_TOPOLOGY)
 		return;
-	if (max_mnest) {
-		stsi(info, 15, 1, max_mnest);
-	} else {
-		for (max_mnest = 6; max_mnest > 1; max_mnest--) {
-			rc = stsi(info, 15, 1, max_mnest);
-			if (rc != -ENOSYS)
-				break;
-		}
-	}
+	stsi(info, 15, 1, topology_max_mnest);
 	seq_printf(m, "CPU Topology HW:     ");
 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 		seq_printf(m, " %d", info->mag[i]);
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index fc957f2eef7c..80ca4ba759f6 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -251,12 +251,10 @@ static void update_cpu_core_map(void)
 
 void store_topology(struct sysinfo_15_1_x *info)
 {
-	int rc;
-
-	rc = stsi(info, 15, 1, 3);
-	if (rc != -ENOSYS)
-		return;
-	stsi(info, 15, 1, 2);
+	if (topology_max_mnest >= 3)
+		stsi(info, 15, 1, 3);
+	else
+		stsi(info, 15, 1, 2);
 }
 
 int arch_update_cpu_topology(void)