1 files changed, 23 insertions, 9 deletions

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 493876daf51a..e89659f46401 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -369,7 +369,7 @@ void __init arch_call_rest_init(void)
 		: : [_frame] "a" (frame));
 }
 
-static void __init setup_lowcore(void)
+static void __init setup_lowcore_dat_off(void)
 {
 	struct lowcore *lc;
 
@@ -380,19 +380,16 @@ static void __init setup_lowcore(void)
 	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
 	lc->restart_psw.mask = PSW_KERNEL_BITS;
 	lc->restart_psw.addr = (unsigned long) restart_int_handler;
-	lc->external_new_psw.mask = PSW_KERNEL_BITS |
-		PSW_MASK_DAT | PSW_MASK_MCHECK;
+	lc->external_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
 	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
 	lc->svc_new_psw.mask = PSW_KERNEL_BITS |
-		PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
+		PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK;
 	lc->svc_new_psw.addr = (unsigned long) system_call;
-	lc->program_new_psw.mask = PSW_KERNEL_BITS |
-		PSW_MASK_DAT | PSW_MASK_MCHECK;
+	lc->program_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
 	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
 	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
 	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
-	lc->io_new_psw.mask = PSW_KERNEL_BITS |
-		PSW_MASK_DAT | PSW_MASK_MCHECK;
+	lc->io_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_MCHECK;
 	lc->io_new_psw.addr = (unsigned long) io_int_handler;
 	lc->clock_comparator = clock_comparator_max;
 	lc->nodat_stack = ((unsigned long) &init_thread_union)
@@ -452,6 +449,17 @@ static void __init setup_lowcore(void)
 	lowcore_ptr[0] = lc;
 }
 
+static void __init setup_lowcore_dat_on(void)
+{
+	struct lowcore *lc;
+
+	lc = lowcore_ptr[0];
+	lc->external_new_psw.mask |= PSW_MASK_DAT;
+	lc->svc_new_psw.mask |= PSW_MASK_DAT;
+	lc->program_new_psw.mask |= PSW_MASK_DAT;
+	lc->io_new_psw.mask |= PSW_MASK_DAT;
+}
+
 static struct resource code_resource = {
 	.name  = "Kernel code",
 	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
@@ -1081,7 +1089,7 @@ void __init setup_arch(char **cmdline_p)
 #endif
 
 	setup_resources();
-	setup_lowcore();
+	setup_lowcore_dat_off();
 	smp_fill_possible_mask();
 	cpu_detect_mhz_feature();
         cpu_init();
@@ -1094,6 +1102,12 @@ void __init setup_arch(char **cmdline_p)
 	 */
         paging_init();
 
+	/*
+	 * After paging_init created the kernel page table, the new PSWs
+	 * in lowcore can now run with DAT enabled.
+	 */
+	setup_lowcore_dat_on();
+
         /* Setup default console */
 	conmode_default();
 	set_preferred_console();