1 files changed, 131 insertions, 0 deletions
diff --git a/arch/sh/include/asm/switch_to_32.h b/arch/sh/include/asm/switch_to_32.h
new file mode 100644
index 000000000..9c93fb91a
--- /dev/null
+++ b/arch/sh/include/asm/switch_to_32.h
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_SH_SWITCH_TO_32_H
+#define __ASM_SH_SWITCH_TO_32_H
+
+#ifdef CONFIG_SH_DSP
+
+#define is_dsp_enabled(tsk)						\
+	(!!(tsk->thread.dsp_status.status & SR_DSP))
+
+#define __restore_dsp(tsk)						\
+do {									\
+	register u32 *__ts2 __asm__ ("r2") =				\
+			(u32 *)&tsk->thread.dsp_status;			\
+	__asm__ __volatile__ (						\
+		".balign 4\n\t"						\
+		"movs.l	@r2+, a0\n\t"					\
+		"movs.l	@r2+, a1\n\t"					\
+		"movs.l	@r2+, a0g\n\t"					\
+		"movs.l	@r2+, a1g\n\t"					\
+		"movs.l	@r2+, m0\n\t"					\
+		"movs.l	@r2+, m1\n\t"					\
+		"movs.l	@r2+, x0\n\t"					\
+		"movs.l	@r2+, x1\n\t"					\
+		"movs.l	@r2+, y0\n\t"					\
+		"movs.l	@r2+, y1\n\t"					\
+		"lds.l	@r2+, dsr\n\t"					\
+		"ldc.l	@r2+, rs\n\t"					\
+		"ldc.l	@r2+, re\n\t"					\
+		"ldc.l	@r2+, mod\n\t"					\
+		: : "r" (__ts2));					\
+} while (0)
+
+#define __save_dsp(tsk)							\
+do {									\
+	register u32 *__ts2 __asm__ ("r2") =				\
+			(u32 *)&tsk->thread.dsp_status + 14;		\
+									\
+	__asm__ __volatile__ (						\
+		".balign 4\n\t"						\
+		"stc.l	mod, @-r2\n\t"					\
+		"stc.l	re, @-r2\n\t"					\
+		"stc.l	rs, @-r2\n\t"					\
+		"sts.l	dsr, @-r2\n\t"					\
+		"movs.l	y1, @-r2\n\t"					\
+		"movs.l	y0, @-r2\n\t"					\
+		"movs.l	x1, @-r2\n\t"					\
+		"movs.l	x0, @-r2\n\t"					\
+		"movs.l	m1, @-r2\n\t"					\
+		"movs.l	m0, @-r2\n\t"					\
+		"movs.l	a1g, @-r2\n\t"					\
+		"movs.l	a0g, @-r2\n\t"					\
+		"movs.l	a1, @-r2\n\t"					\
+		"movs.l	a0, @-r2\n\t"					\
+		: : "r" (__ts2));					\
+} while (0)
+
+#else
+
+#define is_dsp_enabled(tsk)	(0)
+#define __save_dsp(tsk)		do { } while (0)
+#define __restore_dsp(tsk)	do { } while (0)
+#endif
+
+struct task_struct *__switch_to(struct task_struct *prev,
+				struct task_struct *next);
+
+/*
+ *	switch_to() should switch tasks to task nr n, first
+ */
+#define switch_to(prev, next, last)				\
+do {								\
+	register u32 *__ts1 __asm__ ("r1");			\
+	register u32 *__ts2 __asm__ ("r2");			\
+	register u32 *__ts4 __asm__ ("r4");			\
+	register u32 *__ts5 __asm__ ("r5");			\
+	register u32 *__ts6 __asm__ ("r6");			\
+	register u32 __ts7 __asm__ ("r7");			\
+	struct task_struct *__last;				\
+								\
+	if (is_dsp_enabled(prev))				\
+		__save_dsp(prev);				\
+	if (is_dsp_enabled(next))				\
+		__restore_dsp(next);				\
+								\
+	__ts1 = (u32 *)&prev->thread.sp;			\
+	__ts2 = (u32 *)&prev->thread.pc;			\
+	__ts4 = (u32 *)prev;					\
+	__ts5 = (u32 *)next;					\
+	__ts6 = (u32 *)&next->thread.sp;			\
+	__ts7 = next->thread.pc;				\
+								\
+	__asm__ __volatile__ (					\
+		".balign 4\n\t"					\
+		"stc.l	gbr, @-r15\n\t"				\
+		"sts.l	pr, @-r15\n\t"				\
+		"mov.l	r8, @-r15\n\t"				\
+		"mov.l	r9, @-r15\n\t"				\
+		"mov.l	r10, @-r15\n\t"				\
+		"mov.l	r11, @-r15\n\t"				\
+		"mov.l	r12, @-r15\n\t"				\
+		"mov.l	r13, @-r15\n\t"				\
+		"mov.l	r14, @-r15\n\t"				\
+		"mov.l	r15, @r1\t! save SP\n\t"		\
+		"mov.l	@r6, r15\t! change to new stack\n\t"	\
+		"mova	1f, %0\n\t"				\
+		"mov.l	%0, @r2\t! save PC\n\t"			\
+		"mov.l	2f, %0\n\t"				\
+		"jmp	@%0\t! call __switch_to\n\t"		\
+		" lds	r7, pr\t!  with return to new PC\n\t"	\
+		".balign	4\n"				\
+		"2:\n\t"					\
+		".long	__switch_to\n"				\
+		"1:\n\t"					\
+		"mov.l	@r15+, r14\n\t"				\
+		"mov.l	@r15+, r13\n\t"				\
+		"mov.l	@r15+, r12\n\t"				\
+		"mov.l	@r15+, r11\n\t"				\
+		"mov.l	@r15+, r10\n\t"				\
+		"mov.l	@r15+, r9\n\t"				\
+		"mov.l	@r15+, r8\n\t"				\
+		"lds.l	@r15+, pr\n\t"				\
+		"ldc.l	@r15+, gbr\n\t"				\
+		: "=z" (__last)					\
+		: "r" (__ts1), "r" (__ts2), "r" (__ts4),	\
+		  "r" (__ts5), "r" (__ts6), "r" (__ts7)		\
+		: "r3", "t");					\
+								\
+	last = __last;						\
+} while (0)
+
+#endif /* __ASM_SH_SWITCH_TO_32_H */