s390/ctlreg: add struct ctlreg

Add struct ctlreg to enforce strict type checking / usage for control
register functions.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

21 files changed, 97 insertions, 86 deletions

diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c
index 44278ae2512f..bdbfee86d1ac 100644
--- a/arch/s390/boot/vmem.c
+++ b/arch/s390/boot/vmem.c
@@ -12,7 +12,7 @@
 #include "decompressor.h"
 #include "boot.h"
 
-unsigned long __bootdata_preserved(s390_invalid_asce);
+struct ctlreg __bootdata_preserved(s390_invalid_asce);
 
 #ifdef CONFIG_PROC_FS
 atomic_long_t __bootdata_preserved(direct_pages_count[PG_DIRECT_MAP_MAX]);
@@ -422,7 +422,7 @@ void setup_vmem(unsigned long asce_limit)
 		asce_type = _REGION3_ENTRY_EMPTY;
 		asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 	}
-	s390_invalid_asce = invalid_pg_dir | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
+	s390_invalid_asce.val = invalid_pg_dir | _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 
 	crst_table_init((unsigned long *)swapper_pg_dir, asce_type);
 	crst_table_init((unsigned long *)invalid_pg_dir, _REGION3_ENTRY_EMPTY);
@@ -443,12 +443,12 @@ void setup_vmem(unsigned long asce_limit)
 
 	kasan_populate_shadow();
 
-	S390_lowcore.kernel_asce = swapper_pg_dir | asce_bits;
+	S390_lowcore.kernel_asce.val = swapper_pg_dir | asce_bits;
 	S390_lowcore.user_asce = s390_invalid_asce;
 
 	local_ctl_load(1, &S390_lowcore.kernel_asce);
 	local_ctl_load(7, &S390_lowcore.user_asce);
 	local_ctl_load(13, &S390_lowcore.kernel_asce);
 
-	init_mm.context.asce = S390_lowcore.kernel_asce;
+	init_mm.context.asce = S390_lowcore.kernel_asce.val;
 }
diff --git a/arch/s390/include/asm/ctlreg.h b/arch/s390/include/asm/ctlreg.h
index a49459adba9d..57cc610dd997 100644
--- a/arch/s390/include/asm/ctlreg.h
+++ b/arch/s390/include/asm/ctlreg.h
@@ -35,6 +35,10 @@
 
 #include <linux/bug.h>
 
+struct ctlreg {
+	unsigned long val;
+};
+
 #define __local_ctl_load(low, high, array) do {				\
 	struct addrtype {						\
 		char _[sizeof(array)];					\
@@ -43,9 +47,9 @@
 	int _low = low;							\
 	int _esize;							\
 									\
-	_esize = (_high - _low + 1) * sizeof(unsigned long);		\
+	_esize = (_high - _low + 1) * sizeof(struct ctlreg);		\
 	BUILD_BUG_ON(sizeof(struct addrtype) != _esize);		\
-	typecheck(unsigned long, array[0]);				\
+	typecheck(struct ctlreg, array[0]);				\
 	asm volatile(							\
 		"	lctlg	%[_low],%[_high],%[_arr]\n"		\
 		:							\
@@ -62,16 +66,16 @@
 	int _low = low;							\
 	int _esize;							\
 									\
-	_esize = (_high - _low + 1) * sizeof(unsigned long);		\
+	_esize = (_high - _low + 1) * sizeof(struct ctlreg);		\
 	BUILD_BUG_ON(sizeof(struct addrtype) != _esize);		\
-	typecheck(unsigned long, array[0]);				\
+	typecheck(struct ctlreg, array[0]);				\
 	asm volatile(							\
 		"	stctg	%[_low],%[_high],%[_arr]\n"		\
 		: [_arr] "=Q" (*(struct addrtype *)(&array))		\
 		: [_low] "i" (low), [_high] "i" (high));		\
 } while (0)
 
-static __always_inline void local_ctl_load(unsigned int cr, unsigned long *reg)
+static __always_inline void local_ctl_load(unsigned int cr, struct ctlreg *reg)
 {
 	asm volatile(
 		"	lctlg	%[cr],%[cr],%[reg]\n"
@@ -80,7 +84,7 @@ static __always_inline void local_ctl_load(unsigned int cr, unsigned long *reg)
 		: "memory");
 }
 
-static __always_inline void local_ctl_store(unsigned int cr, unsigned long *reg)
+static __always_inline void local_ctl_store(unsigned int cr, struct ctlreg *reg)
 {
 	asm volatile(
 		"	stctg	%[cr],%[cr],%[reg]\n"
@@ -90,19 +94,19 @@ static __always_inline void local_ctl_store(unsigned int cr, unsigned long *reg)
 
 static __always_inline void local_ctl_set_bit(unsigned int cr, unsigned int bit)
 {
-	unsigned long reg;
+	struct ctlreg reg;
 
 	local_ctl_store(cr, &reg);
-	reg |= 1UL << bit;
+	reg.val |= 1UL << bit;
 	local_ctl_load(cr, &reg);
 }
 
 static __always_inline void local_ctl_clear_bit(unsigned int cr, unsigned int bit)
 {
-	unsigned long reg;
+	struct ctlreg reg;
 
 	local_ctl_store(cr, &reg);
-	reg &= ~(1UL << bit);
+	reg.val &= ~(1UL << bit);
 	local_ctl_load(cr, &reg);
 }
 
@@ -122,6 +126,7 @@ static inline void system_ctl_clear_bit(unsigned int cr, unsigned int bit)
 
 union ctlreg0 {
 	unsigned long val;
+	struct ctlreg reg;
 	struct {
 		unsigned long	   : 8;
 		unsigned long tcx  : 1;	/* Transactional-Execution control */
@@ -148,6 +153,7 @@ union ctlreg0 {
 
 union ctlreg2 {
 	unsigned long val;
+	struct ctlreg reg;
 	struct {
 		unsigned long	    : 33;
 		unsigned long ducto : 25;
@@ -161,6 +167,7 @@ union ctlreg2 {
 
 union ctlreg5 {
 	unsigned long val;
+	struct ctlreg reg;
 	struct {
 		unsigned long	    : 33;
 		unsigned long pasteo: 25;
@@ -170,6 +177,7 @@ union ctlreg5 {
 
 union ctlreg15 {
 	unsigned long val;
+	struct ctlreg reg;
 	struct {
 		unsigned long lsea  : 61;
 		unsigned long	    : 3;
diff --git a/arch/s390/include/asm/kprobes.h b/arch/s390/include/asm/kprobes.h
index 83f732ca3af4..21b9e5290c04 100644
--- a/arch/s390/include/asm/kprobes.h
+++ b/arch/s390/include/asm/kprobes.h
@@ -15,6 +15,7 @@
  *		<grundym@us.ibm.com>
  */
 #include <linux/types.h>
+#include <asm/ctlreg.h>
 #include <asm-generic/kprobes.h>
 
 #define BREAKPOINT_INSTRUCTION	0x0002
@@ -65,7 +66,7 @@ struct prev_kprobe {
 struct kprobe_ctlblk {
 	unsigned long kprobe_status;
 	unsigned long kprobe_saved_imask;
-	unsigned long kprobe_saved_ctl[3];
+	struct ctlreg kprobe_saved_ctl[3];
 	struct prev_kprobe prev_kprobe;
 };
 
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 2174f00e188b..3366431dcad5 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -11,6 +11,7 @@
 
 #include <linux/types.h>
 #include <asm/ptrace.h>
+#include <asm/ctlreg.h>
 #include <asm/cpu.h>
 #include <asm/types.h>
 
@@ -139,8 +140,8 @@ struct lowcore {
 	__u32	restart_flags;			/* 0x0384 */
 
 	/* Address space pointer. */
-	unsigned long kernel_asce;		/* 0x0388 */
-	unsigned long user_asce;		/* 0x0390 */
+	struct ctlreg kernel_asce;		/* 0x0388 */
+	struct ctlreg user_asce;		/* 0x0390 */
 
 	/*
 	 * The lpp and current_pid fields form a
@@ -199,7 +200,7 @@ struct lowcore {
 	__u32	clock_comp_save_area[2];	/* 0x1330 */
 	__u64	last_break_save_area;		/* 0x1338 */
 	__u32	access_regs_save_area[16];	/* 0x1340 */
-	unsigned long cregs_save_area[16];	/* 0x1380 */
+	struct ctlreg cregs_save_area[16];	/* 0x1380 */
 	__u8	pad_0x1400[0x1500-0x1400];	/* 0x1400 */
 	/* Cryptography-counter designation */
 	__u64	ccd;				/* 0x1500 */
diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index 0e93275f80f0..757fe6f0d802 100644
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -78,7 +78,7 @@ static inline void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *
 	if (next == &init_mm)
 		S390_lowcore.user_asce = s390_invalid_asce;
 	else
-		S390_lowcore.user_asce = next->context.asce;
+		S390_lowcore.user_asce.val = next->context.asce;
 	cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
 	/* Clear previous user-ASCE from CR7 */
 	local_ctl_load(7, &s390_invalid_asce);
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index fb3ee7758b76..601e87fa8a9a 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -18,6 +18,7 @@
 #include <linux/radix-tree.h>
 #include <linux/atomic.h>
 #include <asm/sections.h>
+#include <asm/ctlreg.h>
 #include <asm/bug.h>
 #include <asm/page.h>
 #include <asm/uv.h>
@@ -25,7 +26,7 @@
 extern pgd_t swapper_pg_dir[];
 extern pgd_t invalid_pg_dir[];
 extern void paging_init(void);
-extern unsigned long s390_invalid_asce;
+extern struct ctlreg s390_invalid_asce;
 
 enum {
 	PG_DIRECT_MAP_4K = 0,
diff --git a/arch/s390/kernel/ctlreg.c b/arch/s390/kernel/ctlreg.c
index 1c9fee1ca4a3..14f715bc5f73 100644
--- a/arch/s390/kernel/ctlreg.c
+++ b/arch/s390/kernel/ctlreg.c
@@ -36,11 +36,11 @@ struct ctl_bit_parms {
 static void ctl_bit_callback(void *info)
 {
 	struct ctl_bit_parms *pp = info;
-	unsigned long regs[16];
+	struct ctlreg regs[16];
 
 	__local_ctl_store(0, 15, regs);
-	regs[pp->cr] &= pp->andval;
-	regs[pp->cr] |= pp->orval;
+	regs[pp->cr].val &= pp->andval;
+	regs[pp->cr].val |= pp->orval;
 	__local_ctl_load(0, 15, regs);
 }
 
@@ -53,8 +53,8 @@ void system_ctl_set_clear_bit(unsigned int cr, unsigned int bit, bool set)
 	pp.andval = set ? -1UL : ~(1UL << bit);
 	system_ctlreg_lock();
 	abs_lc = get_abs_lowcore();
-	abs_lc->cregs_save_area[cr] &= pp.andval;
-	abs_lc->cregs_save_area[cr] |= pp.orval;
+	abs_lc->cregs_save_area[cr].val &= pp.andval;
+	abs_lc->cregs_save_area[cr].val |= pp.orval;
 	put_abs_lowcore(abs_lc);
 	on_each_cpu(ctl_bit_callback, &pp, 1);
 	system_ctlreg_unlock();
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index d4c2ece4f839..f0cf20d4b3c5 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -225,18 +225,18 @@ static void enable_singlestep(struct kprobe_ctlblk *kcb,
 			      unsigned long ip)
 {
 	union {
-		unsigned long regs[3];
+		struct ctlreg regs[3];
 		struct {
-			unsigned long control;
-			unsigned long start;
-			unsigned long end;
+			struct ctlreg control;
+			struct ctlreg start;
+			struct ctlreg end;
 		};
 	} per_kprobe;
 
 	/* Set up the PER control registers %cr9-%cr11 */
-	per_kprobe.control = PER_EVENT_IFETCH;
-	per_kprobe.start = ip;
-	per_kprobe.end = ip;
+	per_kprobe.control.val = PER_EVENT_IFETCH;
+	per_kprobe.start.val = ip;
+	per_kprobe.end.val = ip;
 
 	/* Save control regs and psw mask */
 	__local_ctl_store(9, 11, kcb->kprobe_saved_ctl);
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index fe9d65060fa4..bb0d4d68fcbe 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -94,12 +94,12 @@ static noinline void __machine_kdump(void *image)
 	if (MACHINE_HAS_VX)
 		save_vx_regs((__vector128 *) mcesa->vector_save_area);
 	if (MACHINE_HAS_GS) {
-		local_ctl_store(2, &cr2_old.val);
+		local_ctl_store(2, &cr2_old.reg);
 		cr2_new = cr2_old;
 		cr2_new.gse = 1;
-		local_ctl_load(2, &cr2_new.val);
+		local_ctl_load(2, &cr2_new.reg);
 		save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
-		local_ctl_load(2, &cr2_old.val);
+		local_ctl_load(2, &cr2_old.reg);
 	}
 	/*
 	 * To create a good backchain for this CPU in the dump store_status
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 7880a42896a3..579cebc58d8c 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -131,10 +131,10 @@ static notrace void s390_handle_damage(void)
 	 * Disable low address protection and make machine check new PSW a
 	 * disabled wait PSW. Any additional machine check cannot be handled.
 	 */
-	local_ctl_store(0, &cr0.val);
+	local_ctl_store(0, &cr0.reg);
 	cr0_new = cr0;
 	cr0_new.lap = 0;
-	local_ctl_load(0, &cr0_new.val);
+	local_ctl_load(0, &cr0_new.reg);
 	psw_save = S390_lowcore.mcck_new_psw;
 	psw_bits(S390_lowcore.mcck_new_psw).io = 0;
 	psw_bits(S390_lowcore.mcck_new_psw).ext = 0;
@@ -146,7 +146,7 @@ static notrace void s390_handle_damage(void)
 	 * values. This makes possible system dump analysis easier.
 	 */
 	S390_lowcore.mcck_new_psw = psw_save;
-	local_ctl_load(0, &cr0.val);
+	local_ctl_load(0, &cr0.reg);
 	disabled_wait();
 	while (1);
 }
@@ -269,9 +269,9 @@ static int notrace s390_validate_registers(union mci mci)
 		 */
 		if (!mci.vr && !test_cpu_flag(CIF_MCCK_GUEST))
 			kill_task = 1;
-		cr0.val = S390_lowcore.cregs_save_area[0];
+		cr0.reg = S390_lowcore.cregs_save_area[0];
 		cr0.afp = cr0.vx = 1;
-		local_ctl_load(0, &cr0.val);
+		local_ctl_load(0, &cr0.reg);
 		asm volatile(
 			"	la	1,%0\n"
 			"	VLM	0,15,0,1\n"
@@ -290,7 +290,7 @@ static int notrace s390_validate_registers(union mci mci)
 	if (!mci.ar)
 		kill_task = 1;
 	/* Validate guarded storage registers */
-	cr2.val = S390_lowcore.cregs_save_area[2];
+	cr2.reg = S390_lowcore.cregs_save_area[2];
 	if (cr2.gse) {
 		if (!mci.gs) {
 			/*
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 1e1de907f24d..6a825351ff41 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -45,16 +45,16 @@ void update_cr_regs(struct task_struct *task)
 	union ctlreg2 cr2_old, cr2_new;
 	int cr0_changed, cr2_changed;
 	union {
-		unsigned long regs[3];
+		struct ctlreg regs[3];
 		struct {
-			unsigned long control;
-			unsigned long start;
-			unsigned long end;
+			struct ctlreg control;
+			struct ctlreg start;
+			struct ctlreg end;
 		};
 	} old, new;
 
-	local_ctl_store(0, &cr0_old.val);
-	local_ctl_store(2, &cr2_old.val);
+	local_ctl_store(0, &cr0_old.reg);
+	local_ctl_store(2, &cr2_old.reg);
 	cr0_new = cr0_old;
 	cr2_new = cr2_old;
 	/* Take care of the enable/disable of transactional execution. */
@@ -82,31 +82,31 @@ void update_cr_regs(struct task_struct *task)
 	cr0_changed = cr0_new.val != cr0_old.val;
 	cr2_changed = cr2_new.val != cr2_old.val;
 	if (cr0_changed)
-		local_ctl_load(0, &cr0_new.val);
+		local_ctl_load(0, &cr0_new.reg);
 	if (cr2_changed)
-		local_ctl_load(2, &cr2_new.val);
+		local_ctl_load(2, &cr2_new.reg);
 	/* Copy user specified PER registers */
-	new.control = thread->per_user.control;
-	new.start = thread->per_user.start;
-	new.end = thread->per_user.end;
+	new.control.val = thread->per_user.control;
+	new.start.val = thread->per_user.start;
+	new.end.val = thread->per_user.end;
 
 	/* merge TIF_SINGLE_STEP into user specified PER registers. */
 	if (test_tsk_thread_flag(task, TIF_SINGLE_STEP) ||
 	    test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP)) {
 		if (test_tsk_thread_flag(task, TIF_BLOCK_STEP))
-			new.control |= PER_EVENT_BRANCH;
+			new.control.val |= PER_EVENT_BRANCH;
 		else
-			new.control |= PER_EVENT_IFETCH;
-		new.control |= PER_CONTROL_SUSPENSION;
-		new.control |= PER_EVENT_TRANSACTION_END;
+			new.control.val |= PER_EVENT_IFETCH;
+		new.control.val |= PER_CONTROL_SUSPENSION;
+		new.control.val |= PER_EVENT_TRANSACTION_END;
 		if (test_tsk_thread_flag(task, TIF_UPROBE_SINGLESTEP))
-			new.control |= PER_EVENT_IFETCH;
-		new.start = 0;
-		new.end = -1UL;
+			new.control.val |= PER_EVENT_IFETCH;
+		new.start.val = 0;
+		new.end.val = -1UL;
 	}
 
 	/* Take care of the PER enablement bit in the PSW. */
-	if (!(new.control & PER_EVENT_MASK)) {
+	if (!(new.control.val & PER_EVENT_MASK)) {
 		regs->psw.mask &= ~PSW_MASK_PER;
 		return;
 	}
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 2c4bfe41d284..1c049a65c769 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -791,15 +791,15 @@ static void __init setup_cr(void)
 	__ctl_duct[4] = (unsigned long)__ctl_duald;
 
 	/* Update control registers CR2, CR5 and CR15 */
-	local_ctl_store(2, &cr2.val);
-	local_ctl_store(5, &cr5.val);
-	local_ctl_store(15, &cr15.val);
+	local_ctl_store(2, &cr2.reg);
+	local_ctl_store(5, &cr5.reg);
+	local_ctl_store(15, &cr15.reg);
 	cr2.ducto = (unsigned long)__ctl_duct >> 6;
 	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
 	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
-	local_ctl_load(2, &cr2.val);
-	local_ctl_load(5, &cr5.val);
-	local_ctl_load(15, &cr15.val);
+	local_ctl_load(2, &cr2.reg);
+	local_ctl_load(5, &cr5.reg);
+	local_ctl_load(15, &cr15.reg);
 }
 
 /*
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 90d3502379aa..fbd2801c7061 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -910,7 +910,7 @@ early_param("possible_cpus", _setup_possible_cpus);
 
 int __cpu_disable(void)
 {
-	unsigned long cregs[16];
+	struct ctlreg cregs[16];
 	int cpu;
 
 	/* Handle possible pending IPIs */
@@ -923,9 +923,9 @@ int __cpu_disable(void)
 	pfault_fini();
 	/* Disable interrupt sources via control register. */
 	__local_ctl_store(0, 15, cregs);
-	cregs[0]  &= ~0x0000ee70UL;	/* disable all external interrupts */
-	cregs[6]  &= ~0xff000000UL;	/* disable all I/O interrupts */
-	cregs[14] &= ~0x1f000000UL;	/* disable most machine checks */
+	cregs[0].val  &= ~0x0000ee70UL;	/* disable all external interrupts */
+	cregs[6].val  &= ~0xff000000UL;	/* disable all I/O interrupts */
+	cregs[14].val &= ~0x1f000000UL;	/* disable most machine checks */
 	__local_ctl_load(0, 15, cregs);
 	clear_cpu_flag(CIF_NOHZ_DELAY);
 	return 0;
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index 56f7eb90b44d..61d8dcd95bbc 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -17,17 +17,17 @@
 #ifdef CONFIG_DEBUG_ENTRY
 void debug_user_asce(int exit)
 {
-	unsigned long cr1, cr7;
+	struct ctlreg cr1, cr7;
 
 	local_ctl_store(1, &cr1);
 	local_ctl_store(7, &cr7);
-	if (cr1 == S390_lowcore.kernel_asce && cr7 == S390_lowcore.user_asce)
+	if (cr1.val == S390_lowcore.kernel_asce.val && cr7.val == S390_lowcore.user_asce.val)
 		return;
 	panic("incorrect ASCE on kernel %s\n"
 	      "cr1:    %016lx cr7:  %016lx\n"
 	      "kernel: %016lx user: %016lx\n",
-	      exit ? "exit" : "entry", cr1, cr7,
-	      S390_lowcore.kernel_asce, S390_lowcore.user_asce);
+	      exit ? "exit" : "entry", cr1.val, cr7.val,
+	      S390_lowcore.kernel_asce.val, S390_lowcore.user_asce.val);
 }
 #endif /*CONFIG_DEBUG_ENTRY */
 
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index b51666967aa1..d37a8f607b71 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -287,7 +287,7 @@ static int pt_dump_init(void)
 	 * kernel ASCE. We need this to keep the page table walker functions
 	 * from accessing non-existent entries.
 	 */
-	max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2;
+	max_addr = (S390_lowcore.kernel_asce.val & _REGION_ENTRY_TYPE_MASK) >> 2;
 	max_addr = 1UL << (max_addr * 11 + 31);
 	address_markers[IDENTITY_AFTER_END_NR].start_address = ident_map_size;
 	address_markers[AMODE31_START_NR].start_address = (unsigned long)__samode31;
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index b678295931c3..587b6b64185f 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -196,7 +196,7 @@ static void dump_fault_info(struct pt_regs *regs)
 	pr_cont("mode while using ");
 	switch (get_fault_type(regs)) {
 	case USER_FAULT:
-		asce = S390_lowcore.user_asce;
+		asce = S390_lowcore.user_asce.val;
 		pr_cont("user ");
 		break;
 	case GMAP_FAULT:
@@ -204,7 +204,7 @@ static void dump_fault_info(struct pt_regs *regs)
 		pr_cont("gmap ");
 		break;
 	case KERNEL_FAULT:
-		asce = S390_lowcore.kernel_asce;
+		asce = S390_lowcore.kernel_asce.val;
 		pr_cont("kernel ");
 		break;
 	default:
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index c6ab6f2707d7..7eca10c32caa 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -54,7 +54,7 @@
 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
 pgd_t invalid_pg_dir[PTRS_PER_PGD] __section(".bss..invalid_pg_dir");
 
-unsigned long __bootdata_preserved(s390_invalid_asce);
+struct ctlreg __bootdata_preserved(s390_invalid_asce);
 
 unsigned long empty_zero_page, zero_page_mask;
 EXPORT_SYMBOL(empty_zero_page);
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index b87e96c64b61..631e3a4ee2de 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -75,7 +75,7 @@ static void pgt_set(unsigned long *old, unsigned long new, unsigned long addr,
 			break;
 		}
 		table = (unsigned long *)((unsigned long)old & mask);
-		crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce);
+		crdte(*old, new, table, dtt, addr, S390_lowcore.kernel_asce.val);
 	} else if (MACHINE_HAS_IDTE) {
 		cspg(old, *old, new);
 	} else {
diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
index 27720a687022..61fb157029c8 100644
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -62,7 +62,7 @@ static void __crst_table_upgrade(void *arg)
 
 	/* change all active ASCEs to avoid the creation of new TLBs */
 	if (current->active_mm == mm) {
-		S390_lowcore.user_asce = mm->context.asce;
+		S390_lowcore.user_asce.val = mm->context.asce;
 		local_ctl_load(7, &S390_lowcore.user_asce);
 	}
 	__tlb_flush_local();
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c
index 30a7cd9748fe..ba9b202c5dee 100644
--- a/drivers/s390/char/sclp.c
+++ b/drivers/s390/char/sclp.c
@@ -706,8 +706,8 @@ void
 sclp_sync_wait(void)
 {
 	unsigned long long old_tick;
+	struct ctlreg cr0, cr0_sync;
 	unsigned long flags;
-	unsigned long cr0, cr0_sync;
 	static u64 sync_count;
 	u64 timeout;
 	int irq_context;
@@ -733,8 +733,8 @@ sclp_sync_wait(void)
 	old_tick = local_tick_disable();
 	trace_hardirqs_on();
 	local_ctl_store(0, &cr0);
-	cr0_sync = cr0 & ~CR0_IRQ_SUBCLASS_MASK;
-	cr0_sync |= 1UL << (63 - 54);
+	cr0_sync.val = cr0.val & ~CR0_IRQ_SUBCLASS_MASK;
+	cr0_sync.val |= 1UL << (63 - 54);
 	local_ctl_load(0, &cr0_sync);
 	__arch_local_irq_stosm(0x01);
 	/* Loop until driver state indicates finished request */
diff --git a/drivers/s390/char/sclp_early_core.c b/drivers/s390/char/sclp_early_core.c
index 8cb9fb7098e2..9f6165cafdc3 100644
--- a/drivers/s390/char/sclp_early_core.c
+++ b/drivers/s390/char/sclp_early_core.c
@@ -32,11 +32,11 @@ void sclp_early_wait_irq(void)
 	psw_t psw_ext_save, psw_wait;
 	union ctlreg0 cr0, cr0_new;
 
-	local_ctl_store(0, &cr0.val);
+	local_ctl_store(0, &cr0.reg);
 	cr0_new.val = cr0.val & ~CR0_IRQ_SUBCLASS_MASK;
 	cr0_new.lap = 0;
 	cr0_new.sssm = 1;
-	local_ctl_load(0, &cr0_new.val);
+	local_ctl_load(0, &cr0_new.reg);
 
 	psw_ext_save = S390_lowcore.external_new_psw;
 	psw_mask = __extract_psw();
@@ -59,7 +59,7 @@ void sclp_early_wait_irq(void)
 	} while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
 
 	S390_lowcore.external_new_psw = psw_ext_save;
-	local_ctl_load(0, &cr0.val);
+	local_ctl_load(0, &cr0.reg);
 }
 
 int sclp_early_cmd(sclp_cmdw_t cmd, void *sccb)