1 files changed, 137 insertions, 0 deletions
diff --git a/arch/s390/include/asm/switch_to.h b/arch/s390/include/asm/switch_to.h
new file mode 100644
index 00000000000..18ea9e3f814
--- /dev/null
+++ b/arch/s390/include/asm/switch_to.h
@@ -0,0 +1,137 @@
+/*
+ * Copyright IBM Corp. 1999, 2009
+ *
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#ifndef __ASM_SWITCH_TO_H
+#define __ASM_SWITCH_TO_H
+
+#include <linux/thread_info.h>
+#include <asm/ptrace.h>
+
+extern struct task_struct *__switch_to(void *, void *);
+extern void update_cr_regs(struct task_struct *task);
+
+static inline int test_fp_ctl(u32 fpc)
+{
+	u32 orig_fpc;
+	int rc;
+
+	if (!MACHINE_HAS_IEEE)
+		return 0;
+
+	asm volatile(
+		"	efpc    %1\n"
+		"	sfpc	%2\n"
+		"0:	sfpc	%1\n"
+		"	la	%0,0\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "=d" (rc), "=d" (orig_fpc)
+		: "d" (fpc), "0" (-EINVAL));
+	return rc;
+}
+
+static inline void save_fp_ctl(u32 *fpc)
+{
+	if (!MACHINE_HAS_IEEE)
+		return;
+
+	asm volatile(
+		"       stfpc   %0\n"
+		: "+Q" (*fpc));
+}
+
+static inline int restore_fp_ctl(u32 *fpc)
+{
+	int rc;
+
+	if (!MACHINE_HAS_IEEE)
+		return 0;
+
+	asm volatile(
+		"	lfpc    %1\n"
+		"0:	la	%0,0\n"
+		"1:\n"
+		EX_TABLE(0b,1b)
+		: "=d" (rc) : "Q" (*fpc), "0" (-EINVAL));
+	return rc;
+}
+
+static inline void save_fp_regs(freg_t *fprs)
+{
+	asm volatile("std 0,%0" : "=Q" (fprs[0]));
+	asm volatile("std 2,%0" : "=Q" (fprs[2]));
+	asm volatile("std 4,%0" : "=Q" (fprs[4]));
+	asm volatile("std 6,%0" : "=Q" (fprs[6]));
+	if (!MACHINE_HAS_IEEE)
+		return;
+	asm volatile("std 1,%0" : "=Q" (fprs[1]));
+	asm volatile("std 3,%0" : "=Q" (fprs[3]));
+	asm volatile("std 5,%0" : "=Q" (fprs[5]));
+	asm volatile("std 7,%0" : "=Q" (fprs[7]));
+	asm volatile("std 8,%0" : "=Q" (fprs[8]));
+	asm volatile("std 9,%0" : "=Q" (fprs[9]));
+	asm volatile("std 10,%0" : "=Q" (fprs[10]));
+	asm volatile("std 11,%0" : "=Q" (fprs[11]));
+	asm volatile("std 12,%0" : "=Q" (fprs[12]));
+	asm volatile("std 13,%0" : "=Q" (fprs[13]));
+	asm volatile("std 14,%0" : "=Q" (fprs[14]));
+	asm volatile("std 15,%0" : "=Q" (fprs[15]));
+}
+
+static inline void restore_fp_regs(freg_t *fprs)
+{
+	asm volatile("ld 0,%0" : : "Q" (fprs[0]));
+	asm volatile("ld 2,%0" : : "Q" (fprs[2]));
+	asm volatile("ld 4,%0" : : "Q" (fprs[4]));
+	asm volatile("ld 6,%0" : : "Q" (fprs[6]));
+	if (!MACHINE_HAS_IEEE)
+		return;
+	asm volatile("ld 1,%0" : : "Q" (fprs[1]));
+	asm volatile("ld 3,%0" : : "Q" (fprs[3]));
+	asm volatile("ld 5,%0" : : "Q" (fprs[5]));
+	asm volatile("ld 7,%0" : : "Q" (fprs[7]));
+	asm volatile("ld 8,%0" : : "Q" (fprs[8]));
+	asm volatile("ld 9,%0" : : "Q" (fprs[9]));
+	asm volatile("ld 10,%0" : : "Q" (fprs[10]));
+	asm volatile("ld 11,%0" : : "Q" (fprs[11]));
+	asm volatile("ld 12,%0" : : "Q" (fprs[12]));
+	asm volatile("ld 13,%0" : : "Q" (fprs[13]));
+	asm volatile("ld 14,%0" : : "Q" (fprs[14]));
+	asm volatile("ld 15,%0" : : "Q" (fprs[15]));
+}
+
+static inline void save_access_regs(unsigned int *acrs)
+{
+	typedef struct { int _[NUM_ACRS]; } acrstype;
+
+	asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
+}
+
+static inline void restore_access_regs(unsigned int *acrs)
+{
+	typedef struct { int _[NUM_ACRS]; } acrstype;
+
+	asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
+}
+
+#define switch_to(prev,next,last) do {					\
+	if (prev->mm) {							\
+		save_fp_ctl(&prev->thread.fp_regs.fpc);			\
+		save_fp_regs(prev->thread.fp_regs.fprs);		\
+		save_access_regs(&prev->thread.acrs[0]);		\
+		save_ri_cb(prev->thread.ri_cb);				\
+	}								\
+	if (next->mm) {							\
+		restore_fp_ctl(&next->thread.fp_regs.fpc);		\
+		restore_fp_regs(next->thread.fp_regs.fprs);		\
+		restore_access_regs(&next->thread.acrs[0]);		\
+		restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);	\
+		update_cr_regs(next);					\
+	}								\
+	prev = __switch_to(prev,next);					\
+} while (0)
+
+#endif /* __ASM_SWITCH_TO_H */