C6X: process management
Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>
Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/c6x/kernel/switch_to.S b/arch/c6x/kernel/switch_to.S
new file mode 100644
index 0000000..09177ed
--- /dev/null
+++ b/arch/c6x/kernel/switch_to.S
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2011 Texas Instruments Incorporated
+ * Author: Mark Salter (msalter@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+
+#define SP B15
+
+ /*
+ * void __switch_to(struct thread_info *prev,
+ * struct thread_info *next,
+ * struct task_struct *tsk) ;
+ */
+ENTRY(__switch_to)
+ LDDW .D2T2 *+B4(THREAD_B15_14),B7:B6
+ || MV .L2X A4,B5 ; prev
+ || MV .L1X B4,A5 ; next
+ || MVC .S2 RILC,B1
+
+ STW .D2T2 B3,*+B5(THREAD_PC)
+ || STDW .D1T1 A13:A12,*+A4(THREAD_A13_12)
+ || MVC .S2 ILC,B0
+
+ LDW .D2T2 *+B4(THREAD_PC),B3
+ || LDDW .D1T1 *+A5(THREAD_A13_12),A13:A12
+
+ STDW .D1T1 A11:A10,*+A4(THREAD_A11_10)
+ || STDW .D2T2 B1:B0,*+B5(THREAD_RICL_ICL)
+#ifndef __DSBT__
+ || MVKL .S2 current_ksp,B1
+#endif
+
+ STDW .D2T2 B15:B14,*+B5(THREAD_B15_14)
+ || STDW .D1T1 A15:A14,*+A4(THREAD_A15_14)
+#ifndef __DSBT__
+ || MVKH .S2 current_ksp,B1
+#endif
+
+ ;; Switch to next SP
+ MV .S2 B7,SP
+#ifdef __DSBT__
+ || STW .D2T2 B7,*+B14(current_ksp)
+#else
+ || STW .D2T2 B7,*B1
+ || MV .L2 B6,B14
+#endif
+ || LDDW .D1T1 *+A5(THREAD_RICL_ICL),A1:A0
+
+ STDW .D2T2 B11:B10,*+B5(THREAD_B11_10)
+ || LDDW .D1T1 *+A5(THREAD_A15_14),A15:A14
+
+ STDW .D2T2 B13:B12,*+B5(THREAD_B13_12)
+ || LDDW .D1T1 *+A5(THREAD_A11_10),A11:A10
+
+ B .S2 B3 ; return in next E1
+ || LDDW .D2T2 *+B4(THREAD_B13_12),B13:B12
+
+ LDDW .D2T2 *+B4(THREAD_B11_10),B11:B10
+ NOP
+
+ MV .L2X A0,B0
+ || MV .S1 A6,A4
+
+ MVC .S2 B0,ILC
+ || MV .L2X A1,B1
+
+ MVC .S2 B1,RILC
+ENDPROC(__switch_to)