/*
* linux/arch/m32r/kernel/entry.S
*
* Copyright (c) 2001, 2002 Hirokazu Takata, Hitoshi Yamamoto, H. Kondo
* Copyright (c) 2003 Hitoshi Yamamoto
* Copyright (c) 2004 Hirokazu Takata <takata at linux-m32r.org>
*
* Taken from i386 version.
* Copyright (C) 1991, 1992 Linus Torvalds
*/
/*
* entry.S contains the system-call and fault low-level handling routines.
* This also contains the timer-interrupt handler, as well as all interrupts
* and faults that can result in a task-switch.
*
* NOTE: This code handles signal-recognition, which happens every time
* after a timer-interrupt and after each system call.
*
* Stack layout in 'ret_from_system_call':
* ptrace needs to have all regs on the stack.
* if the order here is changed, it needs to be
* updated in fork.c:copy_thread, signal.c:do_signal,
* ptrace.c and ptrace.h
*
* M32R/M32Rx/M32R2
* @(sp) - r4
* @(0x04,sp) - r5
* @(0x08,sp) - r6
* @(0x0c,sp) - *pt_regs
* @(0x10,sp) - r0
* @(0x14,sp) - r1
* @(0x18,sp) - r2
* @(0x1c,sp) - r3
* @(0x20,sp) - r7
* @(0x24,sp) - r8
* @(0x28,sp) - r9
* @(0x2c,sp) - r10
* @(0x30,sp) - r11
* @(0x34,sp) - r12
* @(0x38,sp) - syscall_nr
* @(0x3c,sp) - acc0h
* @(0x40,sp) - acc0l
* @(0x44,sp) - acc1h ; ISA_DSP_LEVEL2 only
* @(0x48,sp) - acc1l ; ISA_DSP_LEVEL2 only
* @(0x4c,sp) - psw
* @(0x50,sp) - bpc
* @(0x54,sp) - bbpsw
* @(0x58,sp) - bbpc
* @(0x5c,sp) - spu (cr3)
* @(0x60,sp) - fp (r13)
* @(0x64,sp) - lr (r14)
* @(0x68,sp) - spi (cr2)
* @(0x6c,sp) - orig_r0
*/
#include <linux/linkage.h>
#include <asm/irq.h>
#include <asm/unistd.h>
#include <asm/assembler.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/segment.h>
#include <asm/smp.h>
#include <asm/page.h>
#include <asm/m32r.h>
#include <asm/mmu_context.h>
#if !defined(CONFIG_MMU)
#define sys_madvise sys_ni_syscall
#define sys_readahead sys_ni_syscall
#define sys_mprotect sys_ni_syscall
#define sys_msync sys_ni_syscall
#define sys_mlock sys_ni_syscall
#define sys_munlock sys_ni_syscall
#define sys_mlockall sys_ni_syscall
#define sys_munlockall sys_ni_syscall
#define sys_mremap sys_ni_syscall
#define sys_mincore sys_ni_syscall
#define sys_remap_file_pages sys_ni_syscall
#endif /* CONFIG_MMU */
#define R4(reg) @reg
#define R5(reg) @(0x04,reg)
#define R6(reg) @(0x08,reg)
#define PTREGS(reg) @(0x0C,reg)
#define R0(reg) @(0x10,reg)
#define R1(reg) @(0x14,reg)
#define R2(reg) @(0x18,reg)
#define R3(reg) @(0x1C,reg)
#define R7(reg) @(0x20,reg)
#define R8(reg) @(0x24,reg)
#define R9(reg) @(0x28,reg)
#define R10(reg) @(0x2C,reg)
#define R11(reg) @(0x30,reg)
#define R12(reg) @(0x34,reg)
#define SYSCALL_NR(reg) @(0x38,reg)
#define ACC0H(reg) @(0x3C,reg)
#define ACC0L(reg) @(0x40,reg)
#define ACC1H(reg) @(0x44,reg)
#define ACC1L(reg) @(0x48,reg)
#define PSW(reg) @(0x4C,reg)
#define BPC(reg) @(0x50,reg)
#define BBPSW(reg) @(0x54,reg)
#define BBPC(reg) @(0x58,reg)
#define SPU(reg) @(0x5C,reg)
#define FP(reg) @(0x60,reg) /* FP = R13 */
#define LR(reg) @(0x64,reg)
#define SP(reg) @(0x68,reg)
#define ORIG_R0(reg) @(0x6C,reg)
#define nr_syscalls ((syscall_table_size)/4)
#ifdef CONFIG_PREEMPT
#define preempt_stop(x) DISABLE_INTERRUPTS(x)
#else
#define preempt_stop(x)
#define resume_kernel restore_all
#endif
/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) GET_THREAD_INFO reg
.macro GET_THREAD_INFO reg
ldi \reg, #-THREAD_SIZE
and \reg, sp
.endm
ENTRY(ret_from_fork)
pop r0
bl schedule_tail
GET_THREAD_INFO(r8)
bra syscall_exit
/*
* Return to user mode is not as complex as all this looks,
* but we want the default path for a system call return to
* go as quickly as possible which is why some of this is
* less clear than it otherwise should be.
*/
; userspace resumption stub bypassing syscall exit tracing
ALIGN
ret_from_exception:
preempt_stop(r4)
ret_from_intr:
ld r4, PSW(sp)
#ifdef CONFIG_ISA_M32R2
and3 r4, r4, #0x8800 ; check BSM and BPM bits
#else
and3 r4, r4, #0x8000 ; check BSM bit
#endif
beqz r4, resume_kernel
resume_userspace:
DISABLE_INTERRUPTS(r4) ; make sure we don't miss an interrupt
; setting need_resched or sigpending
; between sampling and the iret
GET_THREAD_INFO(r8)
ld r9, @(TI_FLAGS, r8)
and3 r4, r9, #_TIF_WORK_MASK ; is there any work to be done on
; int/exception return?
bnez r4, work_pending
bra restore_all
#ifdef CONFIG_PREEMPT
ENTRY(resume_kernel)
GET_THREAD_INFO(r8)
ld r9, @(TI_PRE_COUNT, r8) ; non-zero preempt_count ?
bnez r9, restore_all
need_resched:
ld r9, @(TI_FLAGS, r8) ; need_resched set ?
and3 r4, r9, #_TIF_NEED_RESCHED
beqz r4, restore_all
ld r4, PSW(sp) ; interrupts off (exception path) ?
and3 r4, r4, #0x4000
beqz r4, restore_all
LDIMM (r4, PREEMPT_ACTIVE)
st r4, @(TI_PRE_COUNT, r8)
ENABLE_INTERRUPTS(r4)
bl schedule
ldi r4, #0
st r4, @(TI_PRE_COUNT, r8)
DISABLE_INTERRUPTS(r4)
bra need_resched
#endif
; system call handler stub
ENTRY(system_call)
SWITCH_TO_KERNEL_STACK
SAVE_ALL
ENABLE_INTERRUPTS(r4) ; Enable interrupt
st sp, PTREGS(sp) ; implicit pt_regs parameter
cmpui r7, #NR_syscalls
bnc syscall_badsys
st r7, SYSCALL_NR(sp) ; syscall_nr
; system call tracing in operation
GET_THREAD_INFO(r8)
ld r9, @(TI_FLAGS, r8)
and3 r4, r9, #_TIF_SYSCALL_TRACE
bnez r4, syscall_trace_entry
syscall_call:
slli r7, #2 ; table jump for the system call
LDIMM (r4, sys_call_table)
add r7, r4
ld r7, @r7
jl r7 ; execute system call
st r0, R0(sp) ; save the return value
syscall_exit:
DISABLE_INTERRUPTS(r4) ; make sure we don't miss an interrupt
; setting need_resched or sigpending
; between sampling and the iret
ld r9, @(TI_FLAGS, r8)
and3 r4, r9, #_TIF_ALLWORK_MASK ; current->work
bnez r4, syscall_exit_work
restore_all:
RESTORE_ALL
# perform work that needs to be done immediately before resumption
# r9 : flags
ALIGN
work_pending:
and3 r4, r9, #_TIF_NEED_RESCHED
beqz r4, work_notifysig
work_resched:
bl schedule
DISABLE_INTERRUPTS(r4) ; make sure we don't miss an interrupt
; setting need_resched or sigpending
; between sampling and the iret
ld r9, @(TI_FLAGS, r8)
and3 r4, r9, #_TIF_WORK_MASK ; is there any work to be done other
; than syscall tracing?
beqz r4, restore_all
and3 r4, r4, #_TIF_NEED_RESCHED
bnez r4, work_resched
work_notifysig: ; deal with pending signals and
; notify-resume requests
mv r0, sp ; arg1 : struct pt_regs *regs
mv r1, r9 ; arg2 : __u32 thread_info_flags
bl do_notify_resume
bra resume_userspace
; perform syscall exit tracing
ALIGN
syscall_trace_entry:
ldi r4, #-ENOSYS
st r4, R0(sp)
bl do_syscall_trace
ld r0, ORIG_R0(sp)
ld r1, R1(sp)
ld r2, R2(sp)
ld r3, R3(sp)
ld r4, R4(sp)
ld r5, R5(sp)
ld r6, R6(sp)
ld r7, SYSCALL_NR(sp)
cmpui r7, #NR_syscalls
bc syscall_call
bra syscall_exit
; perform syscall exit tracing
ALIGN
syscall_exit_work:
ld r9, @(TI_FLAGS, r8)
and3 r4, r9, #_TIF_SYSCALL_TRACE
beqz r4, work_pending
ENABLE_INTERRUPTS(r4) ; could let do_syscall_trace() call
; schedule() instead
bl do_syscall_trace
bra resume_userspace
ALIGN
syscall_fault:
SAVE_ALL
GET_THREAD_INFO(r8)
ldi r4, #-EFAULT
st r4, R0(sp)
bra resume_userspace
ALIGN
syscall_badsys:
ldi r4, #-ENOSYS
st r4, R0(sp)
bra resume_userspace
.global eit_vector
.equ ei_vec_table, eit_vector + 0x0200
/*
* EI handler routine
*/
ENTRY(ei_handler)
#if defined(CONFIG_CHIP_M32700)
; WORKAROUND: force to clear SM bit and use the kernel stack (SPI).
SWITCH_TO_KERNEL_STACK
#endif
SAVE_ALL
mv r1, sp ; arg1(regs)
; get ICU status
seth r0, #shigh(M32R_ICU_ISTS_ADDR)
ld r0, @(low(M32R_ICU_ISTS_ADDR),r0)
push r0
#if defined(CONFIG_SMP)
/*
* If IRQ == 0 --> Nothing to do, Not write IMASK
* If IRQ == IPI --> Do IPI handler, Not write IMASK
* If IRQ != 0, IPI --> Do do_IRQ(), Write IMASK
*/
slli r0, #4
srli r0, #24 ; r0(irq_num<<2)
;; IRQ exist check
#if defined(CONFIG_CHIP_M32700)
/* WORKAROUND: IMASK bug M32700-TS1, TS2 chip. */
bnez r0, 0f
ld24 r14, #0x00070000
seth r0, #shigh(M32R_ICU_IMASK_ADDR)
st r14, @(low(M32R_ICU_IMASK_ADDR),r0)
bra 1f
.fillinsn
0:
#endif /* CONFIG_CHIP_M32700 */
beqz r0, 1f ; if (!irq_num) goto exit
;; IPI check
cmpi r0, #(M32R_IRQ_IPI0<<2) ; ISN < IPI0 check
bc 2f
cmpi r0, #((M32R_IRQ_IPI7+1)<<2) ; ISN > IPI7 check
bnc 2f
LDIMM (r2, ei_vec_table)
add r2, r0
ld r2, @r2
beqz r2, 1f ; if (no IPI handler) goto exit
mv r0, r1 ; arg0(regs)
jl r2
.fillinsn
1:
addi sp, #4
bra restore_all
.fillinsn
2:
srli r0, #2
#else /* not CONFIG_SMP */
srli r0, #22 ; r0(irq)
#endif /* not CONFIG_SMP */
#if defined(CONFIG_PLAT_HAS_INT1ICU)
add3 r2, r0, #-(M32R_IRQ_INT1) ; INT1# interrupt
bnez r2, 3f
seth r0, #shigh(M32R_INT1ICU_ISTS)
lduh r0, @(low(M32R_INT1ICU_ISTS),r0) ; bit10-6 : ISN
slli r0, #21
srli r0, #27 ; ISN
addi r0, #(M32R_INT1ICU_IRQ_BASE)
bra check_end
.fillinsn
3:
#endif /* CONFIG_PLAT_HAS_INT1ICU */
#if defined(CONFIG_PLAT_HAS_INT0ICU)
add3 r2, r0, #-(M32R_IRQ_INT0) ; INT0# interrupt
bnez r2, 4f
seth r0, #shigh(M32R_INT0ICU_ISTS)
lduh r0, @(low(M32R_INT0ICU_ISTS),r0) ; bit10-6 : ISN
slli r0, #21
srli r0, #27 ; ISN
add3 r0, r0, #(M32R_INT0ICU_IRQ_BASE)
bra check_end
.fillinsn
4:
#endif /* CONFIG_PLAT_HAS_INT0ICU */
#if defined(CONFIG_PLAT_HAS_INT2ICU)
add3 r2, r0, #-(M32R_IRQ_INT2) ; INT2# interrupt
bnez r2, 5f
seth r0, #shigh(M32R_INT2ICU_ISTS)
lduh r0, @(low(M32R_INT2ICU_ISTS),r0) ; bit10-6 : ISN
slli r0, #21
srli r0, #27 ; ISN
add3 r0, r0, #(M32R_INT2ICU_IRQ_BASE)
; bra check_end
.fillinsn
5:
#endif /* CONFIG_PLAT_HAS_INT2ICU */
check_end:
bl do_IRQ
pop r14
seth r0, #shigh(M32R_ICU_IMASK_ADDR)
st r14, @(low(M32R_ICU_IMASK_ADDR),r0)
bra ret_from_intr
/*
* Default EIT handler
*/
ALIGN
int_msg:
.asciz "Unknown interrupt\n"
.byte 0
ENTRY(default_eit_handler)
push r0
mvfc r0, psw
push r1
push r2
push r3
push r0
LDIMM (r0, __KERNEL_DS)
mv r0, r1
mv r0, r2
LDIMM (r0, int_msg)
bl printk
pop r0
pop r3
pop r2
pop r1
mvtc r0, psw
pop r0
infinit:
bra infinit
#ifdef CONFIG_MMU
/*
* Access Exception handler
*/
ENTRY(ace_handler)
SWITCH_TO_KERNEL_STACK
SAVE_ALL
seth r2, #shigh(MMU_REG_BASE) /* Check status register */
ld r4, @(low(MESTS_offset),r2)
st r4, @(low(MESTS_offset),r2)
srl3 r1, r4, #4
#ifdef CONFIG_CHIP_M32700
and3 r1, r1, #0x0000ffff
; WORKAROUND: ignore TME bit for the M32700(TS1).
#endif /* CONFIG_CHIP_M32700 */
beqz r1, inst
oprand:
ld r2, @(low(MDEVA_offset),r2) ; set address
srli r1, #1
bra 1f
inst:
and3 r1, r4, #2
srli r1, #1
or3 r1, r1, #8
mvfc r2, bpc ; set address
.fillinsn
1:
mvfc r3, psw
mv r0, sp
and3 r3, r3, 0x800
srli r3, #9
or r1, r3
/*
* do_page_fault():
* r0 : struct pt_regs *regs
* r1 : unsigned long error-code
* r2 : unsigned long address
* error-code:
* +------+------+------+------+
* | bit3 | bit2 | bit1 | bit0 |
* +------+------+------+------+
* bit 3 == 0:means data, 1:means instruction
* bit 2 == 0:means kernel, 1:means user-mode
* bit 1 == 0:means read, 1:means write
* bit 0 == 0:means no page found 1:means protection fault
*
*/
bl do_page_fault
bra ret_from_intr
#endif /* CONFIG_MMU */
ENTRY(alignment_check)
/* void alignment_check(int error_code) */
SWITCH_TO_KERNEL_STACK
SAVE_ALL
ldi r1, #0x30 ; error_code
mv r0, sp ; pt_regs
bl do_alignment_check
error_code:
bra ret_from_exception
ENTRY(rie_handler)
/* void rie_handler(int error_code) */
SWITCH_TO_KERNEL_STACK
SAVE_ALL
ldi r1, #0x20 ; error_code
mv r0, sp ; pt_regs
bl do_rie_handler
bra error_code
ENTRY(pie_handler)
/* void pie_handler(int error_code) */
SWITCH_TO_KERNEL_STACK
SAVE_ALL
ldi r1, #0 ; error_code ; FIXME
mv r0, sp ; pt_regs
bl do_pie_handler
bra error_code
ENTRY(debug_trap)
/* void debug_trap(void) */
.global withdraw_debug_trap
SWITCH_TO_KERNEL_STACK
SAVE_ALL
mv r0, sp ; pt_regs
bl withdraw_debug_trap
ldi r1, #0 ; error_code
mv r0, sp ; pt_regs
bl do_debug_trap
bra error_code
ENTRY(ill_trap)
/* void ill_trap(void) */
SWITCH_TO_KERNEL_STACK
SAVE_ALL
ldi r1, #0 ; error_code ; FIXME
mv r0, sp ; pt_regs
bl do_ill_trap
bra error_code
ENTRY(cache_flushing_handler)
/* void _flush_cache_all(void); */
.global _flush_cache_all
SWITCH_TO_KERNEL_STACK
push r0
push r1
push r2
push r3
push r4
push r5
push r6
push r7
push lr
bl _flush_cache_all
pop lr
pop r7
pop r6
pop r5
pop r4
pop r3
pop r2
pop r1
pop r0
rte
.section .rodata,"a"
#include "syscall_table.S"
syscall_table_size=(.-sys_call_table)
