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* arch/sh/kernel/cpu/sh2/entry.S
* The SH-2 exception entry
* Copyright (C) 2005-2008 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 <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>
! stack
! r0 <- point sp
! r1
! pc
! sr
! r0 = temporary
! r1 = vector (pseudo EXPEVT / INTEVT / TRA)
mov.l r2,@-sp
mov.l r3,@-sp
mov.l $cpu_mode,r2
mov.l @r2,r0
mov.l @(5*4,r15),r3 ! previous SR
or r0,r3 ! set MD
tst r0,r0
bf/s 1f ! previous mode check
mov.l r3,@(5*4,r15) ! update SR
! switch to kernel mode
mov.l __md_bit,r0
mov.l r0,@r2 ! enter kernel mode
mov.l $current_thread_info,r2
mov.l @r2,r2
mov #(THREAD_SIZE >> 8),r0
shll8 r0
add r2,r0
mov r15,r2 ! r2 = user stack top
mov r0,r15 ! switch kernel stack
mov.l r1,@-r15 ! TRA
sts.l macl, @-r15
sts.l mach, @-r15
stc.l gbr, @-r15
mov.l @(5*4,r2),r0
mov.l r0,@-r15 ! original SR
sts.l pr,@-r15
mov.l @(4*4,r2),r0
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 r1,r9 ! save TRA
mov r2,r8 ! copy user -> kernel stack
mov.l @(0,r8),r3
mov.l r3,@-r15
mov.l @(4,r8),r2
mov.l r2,@-r15
mov.l @(12,r8),r1
mov.l r1,@-r15
mov.l @(8,r8),r0
bra 2f
mov.l r0,@-r15
! 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 @(4,r2),r0 ! old R1
mov.l r0,@-r15
mov.l @r2,r0 ! old R0
mov.l r0,@-r15
add #8,r2
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 r1,r9
mov.l @(OFF_R0,r15),r0
mov.l @(OFF_R1,r15),r1
mov.l @(OFF_R2,r15),r2
mov.l @(OFF_R3,r15),r3
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 ! exception handler address
tst r8,r8
bf 3f
mov.l 8f,r8 ! unhandled exception
mov.l 5f,r10
jmp @r8
lds r10,pr
mov r9,r4
mov r15,r5
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 exception_error
mov #0x30,r8
cmp/ge r8,r9 ! vector 0x20-0x2f is systemcall
bt 1f
add #-0x10,r9 ! convert SH2 to SH3/4 ABI
shll2 r9 ! TRA
bra system_call ! jump common systemcall entry
mov r9,r8
/* Unwind the stack and jmp to the debug entry */
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,@(4,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
mov.l @r15+,r15
.align 2
1: .long gdb_vbr_vector
mov r15,r4 ! regs
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
stc sr,r0
or #0xf0,r0
ldc r0,sr ! all interrupt block (same BL = 1)
! restore special register
! overlap exception frame
mov r15,r0
add #17*4,r0
lds.l @r0+,pr
add #4,r0
ldc.l @r0+,gbr
lds.l @r0+,mach
lds.l @r0+,macl
mov r15,r0
mov.l $cpu_mode,r2
mov #OFF_SR,r3
mov.l @(r0,r3),r1
mov.l __md_bit,r3
and r1,r3 ! copy MD bit
mov.l r3,@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
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
.align 2
.long 0x40000000
.long __current_thread_info
.long __cpu_mode
! common exception handler
#include "../../entry-common.S"
! cpu operation mode
! bit30 = MD (compatible SH3/4)
.long 0x40000000
.section .bss
.long 0
.space 4*32