s390/fpu: provide and use lfpc, sfpc, and stfpc inline assemblies

Instead of open-coding lfpc, sfpc, and stfpc inline assemblies at
several locations, provide an fpu_* function for each instruction and
use the function instead.
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/include/asm/fpu-insn.h

@@ -45,6 +45,15 @@ static __always_inline void fpu_ld(unsigned short fpr, freg_t *reg)
 		     : "memory");
 }
 
+static __always_inline void fpu_lfpc(unsigned int *fpc)
+{
+	instrument_read(fpc, sizeof(*fpc));
+	asm volatile("lfpc	%[fpc]"
+		     :
+		     : [fpc] "Q" (*fpc)
+		     : "memory");
+}
+
 /**
  * fpu_lfpc_safe - Load floating point control register safely.
  * @fpc: new value for floating point control register
@@ -82,5 +91,22 @@ static __always_inline void fpu_std(unsigned short fpr, freg_t *reg)
 		     : "memory");
 }
 
+static __always_inline void fpu_sfpc(unsigned int fpc)
+{
+	asm volatile("sfpc	%[fpc]"
+		     :
+		     : [fpc] "d" (fpc)
+		     : "memory");
+}
+
+static __always_inline void fpu_stfpc(unsigned int *fpc)
+{
+	instrument_write(fpc, sizeof(*fpc));
+	asm volatile("stfpc	%[fpc]"
+		     : [fpc] "=Q" (*fpc)
+		     :
+		     : "memory");
+}
+
 #endif /* __ASSEMBLY__ */
 #endif	/* __ASM_S390_FPU_INSN_H */

arch/s390/kernel/fpu.c

@@ -17,10 +17,8 @@ void __kernel_fpu_begin(struct kernel_fpu *state, u32 flags)
 	 * in use by the previous context.
 	 */
 	flags &= state->mask;
-	if (flags & KERNEL_FPC) {
-		/* Save floating point control */
-		asm volatile("stfpc %0" : "=Q" (state->fpc));
-	}
+	if (flags & KERNEL_FPC)
+		fpu_stfpc(&state->fpc);
 	if (!cpu_has_vx()) {
 		if (flags & KERNEL_VXR_LOW)
 			save_fp_regs(state->fprs);
@@ -80,10 +78,8 @@ void __kernel_fpu_end(struct kernel_fpu *state, u32 flags)
 	 * current context.
 	 */
 	flags &= state->mask;
-	if (flags & KERNEL_FPC) {
-		/* Restore floating-point controls */
-		asm volatile("lfpc %0" : : "Q" (state->fpc));
-	}
+	if (flags & KERNEL_FPC)
+		fpu_lfpc(&state->fpc);
 	if (!cpu_has_vx()) {
 		if (flags & KERNEL_VXR_LOW)
 			load_fp_regs(state->fprs);
@@ -176,7 +172,7 @@ void save_fpu_regs(void)
 	state = &current->thread.fpu;
 	regs = current->thread.fpu.regs;
 
-	asm volatile("stfpc %0" : "=Q" (state->fpc));
+	fpu_stfpc(&state->fpc);
 	if (likely(cpu_has_vx())) {
 		asm volatile("lgr	1,%0\n"
 			     "VSTM	0,15,0,1\n"

arch/s390/kernel/process.c

@@ -191,7 +191,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
 void execve_tail(void)
 {
 	current->thread.fpu.fpc = 0;
-	asm volatile("sfpc %0" : : "d" (0));
+	fpu_sfpc(0);
 }
 
 struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *next)