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>

5 files changed, 27 insertions, 16 deletions

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,