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)