riscv: Move trap handler codes to mtrap.S

Currently the M-mode trap handler codes are in start.S. For future
extension, move them to a separate file mtrap.S.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Lukas Auer <lukas.auer@aisec.fraunhofer.de>
Reviewed-by: Anup Patel <anup@brainfault.org>

3 files changed, 112 insertions, 90 deletions

diff --git a/arch/riscv/cpu/Makefile b/arch/riscv/cpu/Makefile
index 2cc6757fcf..6bf6f911c6 100644
--- a/arch/riscv/cpu/Makefile
+++ b/arch/riscv/cpu/Makefile
@@ -4,4 +4,4 @@
 
 extra-y = start.o
 
-obj-y += cpu.o
+obj-y += cpu.o mtrap.o
diff --git a/arch/riscv/cpu/mtrap.S b/arch/riscv/cpu/mtrap.S
new file mode 100644
index 0000000000..a5ad558621
--- /dev/null
+++ b/arch/riscv/cpu/mtrap.S
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * M-mode Trap Handler Code for RISC-V Core
+ *
+ * Copyright (c) 2017 Microsemi Corporation.
+ * Copyright (c) 2017 Padmarao Begari <Padmarao.Begari@microsemi.com>
+ *
+ * Copyright (C) 2017 Andes Technology Corporation
+ * Rick Chen, Andes Technology Corporation <rick@andestech.com>
+ *
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <asm/encoding.h>
+
+#ifdef CONFIG_32BIT
+#define LREG		lw
+#define SREG		sw
+#define REGBYTES	4
+#else
+#define LREG		ld
+#define SREG		sd
+#define REGBYTES	8
+#endif
+
+	.text
+
+	/* trap entry */
+	.align 2
+	.global trap_entry
+trap_entry:
+	addi sp, sp, -32 * REGBYTES
+	SREG x1,   1 * REGBYTES(sp)
+	SREG x2,   2 * REGBYTES(sp)
+	SREG x3,   3 * REGBYTES(sp)
+	SREG x4,   4 * REGBYTES(sp)
+	SREG x5,   5 * REGBYTES(sp)
+	SREG x6,   6 * REGBYTES(sp)
+	SREG x7,   7 * REGBYTES(sp)
+	SREG x8,   8 * REGBYTES(sp)
+	SREG x9,   9 * REGBYTES(sp)
+	SREG x10, 10 * REGBYTES(sp)
+	SREG x11, 11 * REGBYTES(sp)
+	SREG x12, 12 * REGBYTES(sp)
+	SREG x13, 13 * REGBYTES(sp)
+	SREG x14, 14 * REGBYTES(sp)
+	SREG x15, 15 * REGBYTES(sp)
+	SREG x16, 16 * REGBYTES(sp)
+	SREG x17, 17 * REGBYTES(sp)
+	SREG x18, 18 * REGBYTES(sp)
+	SREG x19, 19 * REGBYTES(sp)
+	SREG x20, 20 * REGBYTES(sp)
+	SREG x21, 21 * REGBYTES(sp)
+	SREG x22, 22 * REGBYTES(sp)
+	SREG x23, 23 * REGBYTES(sp)
+	SREG x24, 24 * REGBYTES(sp)
+	SREG x25, 25 * REGBYTES(sp)
+	SREG x26, 26 * REGBYTES(sp)
+	SREG x27, 27 * REGBYTES(sp)
+	SREG x28, 28 * REGBYTES(sp)
+	SREG x29, 29 * REGBYTES(sp)
+	SREG x30, 30 * REGBYTES(sp)
+	SREG x31, 31 * REGBYTES(sp)
+	csrr a0, MODE_PREFIX(cause)
+	csrr a1, MODE_PREFIX(epc)
+	mv a2, sp
+	jal handle_trap
+	csrw MODE_PREFIX(epc), a0
+
+#ifdef CONFIG_RISCV_SMODE
+	/* Remain in S-mode after sret */
+	li t0, SSTATUS_SPP
+#else
+	/* Remain in M-mode after mret */
+	li t0, MSTATUS_MPP
+#endif
+	csrs MODE_PREFIX(status), t0
+	LREG x1,   1 * REGBYTES(sp)
+	LREG x2,   2 * REGBYTES(sp)
+	LREG x3,   3 * REGBYTES(sp)
+	LREG x4,   4 * REGBYTES(sp)
+	LREG x5,   5 * REGBYTES(sp)
+	LREG x6,   6 * REGBYTES(sp)
+	LREG x7,   7 * REGBYTES(sp)
+	LREG x8,   8 * REGBYTES(sp)
+	LREG x9,   9 * REGBYTES(sp)
+	LREG x10, 10 * REGBYTES(sp)
+	LREG x11, 11 * REGBYTES(sp)
+	LREG x12, 12 * REGBYTES(sp)
+	LREG x13, 13 * REGBYTES(sp)
+	LREG x14, 14 * REGBYTES(sp)
+	LREG x15, 15 * REGBYTES(sp)
+	LREG x16, 16 * REGBYTES(sp)
+	LREG x17, 17 * REGBYTES(sp)
+	LREG x18, 18 * REGBYTES(sp)
+	LREG x19, 19 * REGBYTES(sp)
+	LREG x20, 20 * REGBYTES(sp)
+	LREG x21, 21 * REGBYTES(sp)
+	LREG x22, 22 * REGBYTES(sp)
+	LREG x23, 23 * REGBYTES(sp)
+	LREG x24, 24 * REGBYTES(sp)
+	LREG x25, 25 * REGBYTES(sp)
+	LREG x26, 26 * REGBYTES(sp)
+	LREG x27, 27 * REGBYTES(sp)
+	LREG x28, 28 * REGBYTES(sp)
+	LREG x29, 29 * REGBYTES(sp)
+	LREG x30, 30 * REGBYTES(sp)
+	LREG x31, 31 * REGBYTES(sp)
+	addi sp, sp, 32 * REGBYTES
+	MODE_PREFIX(ret)
diff --git a/arch/riscv/cpu/start.S b/arch/riscv/cpu/start.S
index 64246a4e09..47c3bf0434 100644
--- a/arch/riscv/cpu/start.S
+++ b/arch/riscv/cpu/start.S
@@ -198,92 +198,3 @@ call_board_init_r:
  * jump to it ...
  */
 	jr	t4			/* jump to board_init_r() */
-
-/*
- * trap entry
- */
-.align 2
-trap_entry:
-	addi	sp, sp, -32*REGBYTES
-	SREG	x1, 1*REGBYTES(sp)
-	SREG	x2, 2*REGBYTES(sp)
-	SREG	x3, 3*REGBYTES(sp)
-	SREG	x4, 4*REGBYTES(sp)
-	SREG	x5, 5*REGBYTES(sp)
-	SREG	x6, 6*REGBYTES(sp)
-	SREG	x7, 7*REGBYTES(sp)
-	SREG	x8, 8*REGBYTES(sp)
-	SREG	x9, 9*REGBYTES(sp)
-	SREG	x10, 10*REGBYTES(sp)
-	SREG	x11, 11*REGBYTES(sp)
-	SREG	x12, 12*REGBYTES(sp)
-	SREG	x13, 13*REGBYTES(sp)
-	SREG	x14, 14*REGBYTES(sp)
-	SREG	x15, 15*REGBYTES(sp)
-	SREG	x16, 16*REGBYTES(sp)
-	SREG	x17, 17*REGBYTES(sp)
-	SREG	x18, 18*REGBYTES(sp)
-	SREG	x19, 19*REGBYTES(sp)
-	SREG	x20, 20*REGBYTES(sp)
-	SREG	x21, 21*REGBYTES(sp)
-	SREG	x22, 22*REGBYTES(sp)
-	SREG	x23, 23*REGBYTES(sp)
-	SREG	x24, 24*REGBYTES(sp)
-	SREG	x25, 25*REGBYTES(sp)
-	SREG	x26, 26*REGBYTES(sp)
-	SREG	x27, 27*REGBYTES(sp)
-	SREG	x28, 28*REGBYTES(sp)
-	SREG	x29, 29*REGBYTES(sp)
-	SREG	x30, 30*REGBYTES(sp)
-	SREG	x31, 31*REGBYTES(sp)
-	csrr	a0, MODE_PREFIX(cause)
-	csrr	a1, MODE_PREFIX(epc)
-	mv	a2, sp
-	jal	handle_trap
-	csrw	MODE_PREFIX(epc), a0
-
-#ifdef CONFIG_RISCV_SMODE
-/*
- * Remain in S-mode after sret
- */
-	li	t0, SSTATUS_SPP
-#else
-/*
- * Remain in M-mode after mret
- */
-	li	t0, MSTATUS_MPP
-#endif
-	csrs	MODE_PREFIX(status), t0
-	LREG	x1, 1*REGBYTES(sp)
-	LREG	x2, 2*REGBYTES(sp)
-	LREG	x3, 3*REGBYTES(sp)
-	LREG	x4, 4*REGBYTES(sp)
-	LREG	x5, 5*REGBYTES(sp)
-	LREG	x6, 6*REGBYTES(sp)
-	LREG	x7, 7*REGBYTES(sp)
-	LREG	x8, 8*REGBYTES(sp)
-	LREG	x9, 9*REGBYTES(sp)
-	LREG	x10, 10*REGBYTES(sp)
-	LREG	x11, 11*REGBYTES(sp)
-	LREG	x12, 12*REGBYTES(sp)
-	LREG	x13, 13*REGBYTES(sp)
-	LREG	x14, 14*REGBYTES(sp)
-	LREG	x15, 15*REGBYTES(sp)
-	LREG	x16, 16*REGBYTES(sp)
-	LREG	x17, 17*REGBYTES(sp)
-	LREG	x18, 18*REGBYTES(sp)
-	LREG	x19, 19*REGBYTES(sp)
-	LREG	x20, 20*REGBYTES(sp)
-	LREG	x21, 21*REGBYTES(sp)
-	LREG	x22, 22*REGBYTES(sp)
-	LREG	x23, 23*REGBYTES(sp)
-	LREG	x24, 24*REGBYTES(sp)
-	LREG	x25, 25*REGBYTES(sp)
-	LREG	x26, 26*REGBYTES(sp)
-	LREG	x27, 27*REGBYTES(sp)
-	LREG	x28, 28*REGBYTES(sp)
-	LREG	x29, 29*REGBYTES(sp)
-	LREG	x30, 30*REGBYTES(sp)
-	LREG	x31, 31*REGBYTES(sp)
-	addi	sp, sp, 32*REGBYTES
-	MODE_PREFIX(ret)