/*
* arch/score/kernel/entry.S
*
* Score Processor version.
*
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
* Chen Liqin <liqin.chen@sunplusct.com>
* Lennox Wu <lennox.wu@sunplusct.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/asmmacro.h>
#include <asm/thread_info.h>
#include <asm/unistd.h>
/*
* disable interrupts.
*/
.macro disable_irq
mfcr r8, cr0
srli r8, r8, 1
slli r8, r8, 1
mtcr r8, cr0
nop
nop
nop
nop
nop
.endm
/*
* enable interrupts.
*/
.macro enable_irq
mfcr r8, cr0
ori r8, 1
mtcr r8, cr0
nop
nop
nop
nop
nop
.endm
__INIT
ENTRY(debug_exception_vector)
nop!
nop!
nop!
nop!
nop!
nop!
nop!
nop!
ENTRY(general_exception_vector) # should move to addr 0x200
j general_exception
nop!
nop!
nop!
nop!
nop!
nop!
ENTRY(interrupt_exception_vector) # should move to addr 0x210
j interrupt_exception
nop!
nop!
nop!
nop!
nop!
nop!
.section ".text", "ax"
.align 2;
general_exception:
mfcr r31, cr2
nop
la r30, exception_handlers
andi r31, 0x1f # get ecr.exc_code
slli r31, r31, 2
add r30, r30, r31
lw r30, [r30]
br r30
interrupt_exception:
SAVE_ALL
mfcr r4, cr2
nop
lw r16, [r28, TI_REGS]
sw r0, [r28, TI_REGS]
la r3, ret_from_irq
srli r4, r4, 18 # get ecr.ip[7:2], interrupt No.
mv r5, r0
j do_IRQ
ENTRY(handle_nmi) # NMI #1
SAVE_ALL
mv r4, r0
la r8, nmi_exception_handler
brl r8
j restore_all
ENTRY(handle_adelinsn) # AdEL-instruction #2
SAVE_ALL
mfcr r8, cr6
nop
nop
sw r8, [r0, PT_EMA]
mv r4, r0
la r8, do_adelinsn
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_ibe) # BusEL-instruction #5
SAVE_ALL
mv r4, r0
la r8, do_be
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_pel) # P-EL #6
SAVE_ALL
mv r4, r0
la r8, do_pel
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_ccu) # CCU #8
SAVE_ALL
mv r4, r0
la r8, do_ccu
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_ri) # RI #9
SAVE_ALL
mv r4, r0
la r8, do_ri
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_tr) # Trap #10
SAVE_ALL
mv r4, r0
la r8, do_tr
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_adedata) # AdES-instruction #12
SAVE_ALL
mfcr r8, cr6
nop
nop
sw r8, [r0, PT_EMA]
mv r4, r0
la r8, do_adedata
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_cee) # CeE #16
SAVE_ALL
mv r4, r0
la r8, do_cee
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_cpe) # CpE #17
SAVE_ALL
mv r4, r0
la r8, do_cpe
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_dbe) # BusEL-data #18
SAVE_ALL
mv r4, r0
la r8, do_be
brl r8
mv r4, r0
j ret_from_exception
nop
ENTRY(handle_reserved) # others
SAVE_ALL
mv r4, r0
la r8, do_reserved
brl r8
mv r4, r0
j ret_from_exception
nop
#ifndef CONFIG_PREEMPT
#define resume_kernel restore_all
#else
#define __ret_from_irq ret_from_exception
#endif
.align 2
#ifndef CONFIG_PREEMPT
ENTRY(ret_from_exception)
disable_irq # preempt stop
nop
j __ret_from_irq
nop
#endif
ENTRY(ret_from_irq)
sw r16, [r28, TI_REGS]
ENTRY(__ret_from_irq)
lw r8, [r0, PT_PSR] # returning to kernel mode?
andri.c r8, r8, KU_USER
beq resume_kernel
resume_userspace:
disable_irq
lw r6, [r28, TI_FLAGS] # current->work
li r8, _TIF_WORK_MASK
and.c r8, r8, r6 # ignoring syscall_trace
bne work_pending
nop
j restore_all
nop
#ifdef CONFIG_PREEMPT
resume_kernel:
disable_irq
lw r8, [r28, TI_PRE_COUNT]
cmpz.c r8
bne restore_all
need_resched:
lw r8, [r28, TI_FLAGS]
andri.c r9, r8, _TIF_NEED_RESCHED
beq restore_all
lw r8, [r28, PT_PSR] # Interrupts off?
andri.c r8, r8, 1
beq restore_all
bl preempt_schedule_irq
nop
j need_resched
nop
#endif
ENTRY(ret_from_kernel_thread)
bl schedule_tail # r4=struct task_struct *prev
nop
mv r4, r13
brl r12
j syscall_exit
ENTRY(ret_from_fork)
bl schedule_tail # r4=struct task_struct *prev
ENTRY(syscall_exit)
nop
disable_irq
lw r6, [r28, TI_FLAGS] # current->work
li r8, _TIF_WORK_MASK
and.c r8, r6, r8
bne syscall_exit_work
ENTRY(restore_all) # restore full frame
RESTORE_ALL_AND_RET
work_pending:
andri.c r8, r6, _TIF_NEED_RESCHED # r6 is preloaded with TI_FLAGS
beq work_notifysig
work_resched:
bl schedule
nop
disable_irq
lw r6, [r28, TI_FLAGS]
li r8, _TIF_WORK_MASK
and.c r8, r6, r8 # is there any work to be done
# other than syscall tracing?
beq restore_all
andri.c r8, r6, _TIF_NEED_RESCHED
bne work_resched
work_notifysig:
mv r4, r0
li r5, 0
bl do_notify_resume # r6 already loaded
nop
j resume_userspace
nop
ENTRY(syscall_exit_work)
li r8, _TIF_SYSCALL_TRACE
and.c r8, r8, r6 # r6 is preloaded with TI_FLAGS
beq work_pending # trace bit set?
nop
enable_irq
mv r4, r0
li r5, 1
bl do_syscall_trace
nop
b resume_userspace
nop
.macro save_context reg
sw r12, [\reg, THREAD_REG12];
sw r13, [\reg, THREAD_REG13];
sw r14, [\reg, THREAD_REG14];
sw r15, [\reg, THREAD_REG15];
sw r16, [\reg, THREAD_REG16];
sw r17, [\reg, THREAD_REG17];
sw r18, [\reg, THREAD_REG18];
sw r19, [\reg, THREAD_REG19];
sw r20, [\reg, THREAD_REG20];
sw r21, [\reg, THREAD_REG21];
sw r29, [\reg, THREAD_REG29];
sw r2, [\reg, THREAD_REG2];
sw r0, [\reg, THREAD_REG0]
.endm
.macro restore_context reg
lw r12, [\reg, THREAD_REG12];
lw r13, [\reg, THREAD_REG13];
lw r14, [\reg, THREAD_REG14];
lw r15, [\reg, THREAD_REG15];
lw r16, [\reg, THREAD_REG16];
lw r17, [\reg, THREAD_REG17];
lw r18, [\reg, THREAD_REG18];
lw r19, [\reg, THREAD_REG19];
lw r20, [\reg, THREAD_REG20];
lw r21, [\reg, THREAD_REG21];
lw r29, [\reg, THREAD_REG29];
lw r0, [\reg, THREAD_REG0];
lw r2, [\reg, THREAD_REG2];
lw r3, [\reg, THREAD_REG3]
.endm
/*
* task_struct *resume(task_struct *prev, task_struct *next,
* struct thread_info *next_ti)
*/
ENTRY(resume)
mfcr r9, cr0
nop
nop
sw r9, [r4, THREAD_PSR]
save_context r4
sw r3, [r4, THREAD_REG3]
mv r28, r6
restore_context r5
mv r8, r6
addi r8, KERNEL_STACK_SIZE
subi r8, 32
la r9, kernelsp;
sw r8, [r9];
mfcr r9, cr0
ldis r7, 0x00ff
nop
and r9, r9, r7
lw r6, [r5, THREAD_PSR]
not r7, r7
and r6, r6, r7
or r6, r6, r9
mtcr r6, cr0
nop; nop; nop; nop; nop
br r3
ENTRY(handle_sys)
SAVE_ALL
sw r8, [r0, 16] # argument 5 from user r8
sw r9, [r0, 20] # argument 6 from user r9
enable_irq
sw r4, [r0, PT_ORIG_R4] #for restart syscall
sw r7, [r0, PT_ORIG_R7] #for restart syscall
sw r27, [r0, PT_IS_SYSCALL] # it from syscall
lw r9, [r0, PT_EPC] # skip syscall on return
addi r9, 4
sw r9, [r0, PT_EPC]
cmpi.c r27, __NR_syscalls # check syscall number
bcs illegal_syscall
slli r8, r27, 2 # get syscall routine
la r11, sys_call_table
add r11, r11, r8
lw r10, [r11] # get syscall entry
cmpz.c r10
beq illegal_syscall
lw r8, [r28, TI_FLAGS]
li r9, _TIF_SYSCALL_TRACE
and.c r8, r8, r9
bne syscall_trace_entry
brl r10 # Do The Real system call
cmpi.c r4, 0
blt 1f
ldi r8, 0
sw r8, [r0, PT_R7]
b 2f
1:
cmpi.c r4, -MAX_ERRNO - 1
ble 2f
ldi r8, 0x1;
sw r8, [r0, PT_R7]
neg r4, r4
2:
sw r4, [r0, PT_R4] # save result
syscall_return:
disable_irq
lw r6, [r28, TI_FLAGS] # current->work
li r8, _TIF_WORK_MASK
and.c r8, r6, r8
bne syscall_return_work
j restore_all
syscall_return_work:
j syscall_exit_work
syscall_trace_entry:
mv r16, r10
mv r4, r0
li r5, 0
bl do_syscall_trace
mv r8, r16
lw r4, [r0, PT_R4] # Restore argument registers
lw r5, [r0, PT_R5]
lw r6, [r0, PT_R6]
lw r7, [r0, PT_R7]
brl r8
li r8, -MAX_ERRNO - 1
sw r8, [r0, PT_R7] # set error flag
neg r4, r4 # error
sw r4, [r0, PT_R0] # set flag for syscall
# restarting
1: sw r4, [r0, PT_R2] # result
j syscall_exit
illegal_syscall:
ldi r4, -ENOSYS # error
sw r4, [r0, PT_ORIG_R4]
sw r4, [r0, PT_R4]
ldi r9, 1 # set error flag
sw r9, [r0, PT_R7]
j syscall_return
ENTRY(sys_rt_sigreturn)
mv r4, r0
la r8, score_rt_sigreturn
br r8
