--- /dev/null
+/*
+ * arch/sh/kernel/cpu/sh2/entry.S
+ *
+ * The SH-2 exception entry
+ *
+ * Copyright (C) 2005,2006 Yoshinori Sato
+ * Copyright (C) 2005 AXE,Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/cpu/mmu_context.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+#include <asm/page.h>
+
+/* Offsets to the stack */
+OFF_R0 = 0 /* Return value. New ABI also arg4 */
+OFF_R1 = 4 /* New ABI: arg5 */
+OFF_R2 = 8 /* New ABI: arg6 */
+OFF_R3 = 12 /* New ABI: syscall_nr */
+OFF_R4 = 16 /* New ABI: arg0 */
+OFF_R5 = 20 /* New ABI: arg1 */
+OFF_R6 = 24 /* New ABI: arg2 */
+OFF_R7 = 28 /* New ABI: arg3 */
+OFF_SP = (15*4)
+OFF_PC = (16*4)
+OFF_SR = (16*4+2*4)
+OFF_TRA = (16*4+6*4)
+
+#include <asm/entry-macros.S>
+
+ENTRY(exception_handler)
+ ! already saved r0/r1
+ mov.l r2,@-sp
+ mov.l r3,@-sp
+ mov r0,r1
+ cli
+ mov.l $cpu_mode,r2
+ mov.l @r2,r0
+ mov.l @(5*4,r15),r3 ! previous SR
+ shll2 r3 ! set "S" flag
+ rotl r0 ! T <- "S" flag
+ rotl r0 ! "S" flag is LSB
+ rotcr r3 ! T -> r3:b30
+ shlr r3
+ shlr r0
+ bt/s 1f
+ mov.l r3,@(5*4,r15) ! copy cpu mode to SR
+ ! switch to kernel mode
+ mov #1,r0
+ rotr r0
+ rotr r0
+ mov.l r0,@r2 ! enter kernel mode
+ mov.l $current_thread_info,r2
+ mov.l @r2,r2
+ mov #0x20,r0
+ shll8 r0
+ add r2,r0
+ mov r15,r2 ! r2 = user stack top
+ mov r0,r15 ! switch kernel stack
+ add #-4,r15 ! dummy
+ mov.l r1,@-r15 ! TRA
+ sts.l macl, @-r15
+ sts.l mach, @-r15
+ stc.l gbr, @-r15
+ mov.l @(4*4,r2),r0
+ mov.l @(5*4,r2),r1
+ mov.l r1,@-r15 ! original SR
+ sts.l pr,@-r15
+ mov.l r0,@-r15 ! original PC
+ mov r2,r3
+ add #(4+2)*4,r3 ! rewind r0 - r3 + exception frame
+ mov.l r3,@-r15 ! original SP
+ mov.l r14,@-r15
+ mov.l r13,@-r15
+ mov.l r12,@-r15
+ mov.l r11,@-r15
+ mov.l r10,@-r15
+ mov.l r9,@-r15
+ mov.l r8,@-r15
+ mov.l r7,@-r15
+ mov.l r6,@-r15
+ mov.l r5,@-r15
+ mov.l r4,@-r15
+ mov r2,r8 ! copy user -> kernel stack
+ mov.l @r8+,r3
+ mov.l r3,@-r15
+ mov.l @r8+,r2
+ mov.l r2,@-r15
+ mov.l @r8+,r1
+ mov.l r1,@-r15
+ mov.l @r8+,r0
+ bra 2f
+ mov.l r0,@-r15
+1:
+ ! in kernel exception
+ mov #(22-4-4-1)*4+4,r0
+ mov r15,r2
+ sub r0,r15
+ mov.l @r2+,r0 ! old R3
+ mov.l r0,@-r15
+ mov.l @r2+,r0 ! old R2
+ mov.l r0,@-r15
+ mov.l @r2+,r0 ! old R1
+ mov.l r0,@-r15
+ mov.l @r2+,r0 ! old R0
+ mov.l r0,@-r15
+ mov.l @r2+,r3 ! old PC
+ mov.l @r2+,r0 ! old SR
+ add #-4,r2 ! exception frame stub (sr)
+ mov.l r1,@-r2 ! TRA
+ sts.l macl, @-r2
+ sts.l mach, @-r2
+ stc.l gbr, @-r2
+ mov.l r0,@-r2 ! save old SR
+ sts.l pr,@-r2
+ mov.l r3,@-r2 ! save old PC
+ mov r2,r0
+ add #8*4,r0
+ mov.l r0,@-r2 ! save old SP
+ mov.l r14,@-r2
+ mov.l r13,@-r2
+ mov.l r12,@-r2
+ mov.l r11,@-r2
+ mov.l r10,@-r2
+ mov.l r9,@-r2
+ mov.l r8,@-r2
+ mov.l r7,@-r2
+ mov.l r6,@-r2
+ mov.l r5,@-r2
+ mov.l r4,@-r2
+ mov.l @(OFF_R0,r15),r0
+ mov.l @(OFF_R1,r15),r1
+ mov.l @(OFF_R2,r15),r2
+ mov.l @(OFF_R3,r15),r3
+2:
+ mov #OFF_TRA,r8
+ add r15,r8
+ mov.l @r8,r9
+ mov #64,r8
+ cmp/hs r8,r9
+ bt interrupt_entry ! vec >= 64 is interrupt
+ mov #32,r8
+ cmp/hs r8,r9
+ bt trap_entry ! 64 > vec >= 32 is trap
+ mov.l 4f,r8
+ mov r9,r4
+ shll2 r9
+ add r9,r8
+ mov.l @r8,r8
+ mov #0,r9
+ cmp/eq r9,r8
+ bf 3f
+ mov.l 8f,r8 ! unhandled exception
+3:
+ mov.l 5f,r10
+ jmp @r8
+ lds r10,pr
+
+interrupt_entry:
+ mov r9,r4
+ mov.l 6f,r9
+ mov.l 7f,r8
+ jmp @r8
+ lds r9,pr
+
+ .align 2
+4: .long exception_handling_table
+5: .long ret_from_exception
+6: .long ret_from_irq
+7: .long do_IRQ
+8: .long do_exception_error
+
+trap_entry:
+ /* verbose BUG trapa entry check */
+ mov #0x3e,r8
+ cmp/ge r8,r9
+ bf/s 1f
+ add #-0x10,r9
+ add #0x10,r9
+1:
+ shll2 r9 ! TRA
+ mov #OFF_TRA,r8
+ add r15,r8
+ mov.l r9,@r8
+ mov r9,r8
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 2f, r9
+ jsr @r9
+ nop
+#endif
+ sti
+ bra system_call
+ nop
+
+ .align 2
+#ifdef CONFIG_TRACE_IRQFLAGS
+2: .long trace_hardirqs_on
+#endif
+
+#if defined(CONFIG_SH_STANDARD_BIOS)
+ /* Unwind the stack and jmp to the debug entry */
+debug_kernel_fw:
+ mov r15,r0
+ add #(22-4)*4-4,r0
+ ldc.l @r0+,gbr
+ lds.l @r0+,mach
+ lds.l @r0+,macl
+ mov r15,r0
+ mov.l @(OFF_SP,r0),r1
+ mov #OFF_SR,r2
+ mov.l @(r0,r2),r3
+ mov.l r3,@-r1
+ mov #OFF_SP,r2
+ mov.l @(r0,r2),r3
+ mov.l r3,@-r1
+ mov r15,r0
+ add #(22-4)*4-8,r0
+ mov.l 1f,r2
+ mov.l @r2,r2
+ stc sr,r3
+ mov.l r2,@r0
+ mov.l r3,@r0
+ mov.l r1,@(8,r0)
+ mov.l @r15+, r0
+ mov.l @r15+, r1
+ mov.l @r15+, r2
+ mov.l @r15+, r3
+ mov.l @r15+, r4
+ mov.l @r15+, r5
+ mov.l @r15+, r6
+ mov.l @r15+, r7
+ mov.l @r15+, r8
+ mov.l @r15+, r9
+ mov.l @r15+, r10
+ mov.l @r15+, r11
+ mov.l @r15+, r12
+ mov.l @r15+, r13
+ mov.l @r15+, r14
+ add #8,r15
+ lds.l @r15+, pr
+ rte
+ mov.l @r15+,r15
+ .align 2
+1: .long gdb_vbr_vector
+#endif /* CONFIG_SH_STANDARD_BIOS */
+
+ENTRY(address_error_handler)
+ mov r15,r4 ! regs
+ add #4,r4
+ mov #OFF_PC,r0
+ mov.l @(r0,r15),r6 ! pc
+ mov.l 1f,r0
+ jmp @r0
+ mov #0,r5 ! writeaccess is unknown
+ .align 2
+
+1: .long do_address_error
+
+restore_all:
+ cli
+#ifdef CONFIG_TRACE_IRQFLAGS
+ mov.l 1f, r0
+ jsr @r0
+ nop
+#endif
+ mov r15,r0
+ mov.l $cpu_mode,r2
+ mov #OFF_SR,r3
+ mov.l @(r0,r3),r1
+ mov.l r1,@r2
+ shll2 r1 ! clear MD bit
+ shlr2 r1
+ mov.l @(OFF_SP,r0),r2
+ add #-8,r2
+ mov.l r2,@(OFF_SP,r0) ! point exception frame top
+ mov.l r1,@(4,r2) ! set sr
+ mov #OFF_PC,r3
+ mov.l @(r0,r3),r1
+ mov.l r1,@r2 ! set pc
+ add #4*16+4,r0
+ lds.l @r0+,pr
+ add #4,r0 ! skip sr
+ ldc.l @r0+,gbr
+ lds.l @r0+,mach
+ lds.l @r0+,macl
+ get_current_thread_info r0, r1
+ mov.l $current_thread_info,r1
+ mov.l r0,@r1
+ mov.l @r15+,r0
+ mov.l @r15+,r1
+ mov.l @r15+,r2
+ mov.l @r15+,r3
+ mov.l @r15+,r4
+ mov.l @r15+,r5
+ mov.l @r15+,r6
+ mov.l @r15+,r7
+ mov.l @r15+,r8
+ mov.l @r15+,r9
+ mov.l @r15+,r10
+ mov.l @r15+,r11
+ mov.l @r15+,r12
+ mov.l @r15+,r13
+ mov.l @r15+,r14
+ mov.l @r15,r15
+ rte
+ nop
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+1: .long trace_hardirqs_off
+#endif
+$current_thread_info:
+ .long __current_thread_info
+$cpu_mode:
+ .long __cpu_mode
+
+! common exception handler
+#include "../../entry-common.S"
+
+ .data
+! cpu operation mode
+! bit30 = MD (compatible SH3/4)
+__cpu_mode:
+ .long 0x40000000
+
+ .section .bss
+__current_thread_info:
+ .long 0
+
+ENTRY(exception_handling_table)
+ .space 4*32
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