Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* -*- mode: asm -*-
 *
 *  linux/arch/h8300/platform/h8300h/entry.S
 *
 *  Yoshinori Sato <ysato@users.sourceforge.jp>
 *  David McCullough <davidm@snapgear.com>
 *
 */

/*
 *  entry.S
 *  include exception/interrupt gateway
 *          system call entry
 */

#include <linux/sys.h>
#include <asm/unistd.h>
#include <asm/setup.h>
#include <asm/segment.h>
#include <asm/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/errno.h>

#if defined(CONFIG_CPU_H8300H)
#define USERRET 8
INTERRUPTS = 64
        .h8300h
        .macro  SHLL2 reg
        shll.l  \reg
        shll.l  \reg
        .endm
        .macro  SHLR2 reg
        shlr.l  \reg
        shlr.l  \reg
        .endm
        .macro  SAVEREGS
        mov.l   er0,@-sp
        mov.l   er1,@-sp
        mov.l   er2,@-sp
        mov.l   er3,@-sp
        .endm
        .macro  RESTOREREGS
        mov.l   @sp+,er3
        mov.l   @sp+,er2
        .endm
        .macro  SAVEEXR
        .endm
        .macro  RESTOREEXR
        .endm
#endif
#if defined(CONFIG_CPU_H8S)
#define USERRET 10
#define USEREXR 8
INTERRUPTS = 128
        .h8300s
        .macro  SHLL2 reg
        shll.l  #2,\reg
        .endm
        .macro  SHLR2 reg
        shlr.l  #2,\reg
        .endm
        .macro  SAVEREGS
        stm.l   er0-er3,@-sp
        .endm
        .macro  RESTOREREGS
        ldm.l   @sp+,er2-er3
        .endm
        .macro  SAVEEXR
        mov.w   @(USEREXR:16,er0),r1
        mov.w   r1,@(LEXR-LER3:16,sp)           /* copy EXR */
        .endm
        .macro  RESTOREEXR
        mov.w   @(LEXR-LER1:16,sp),r1           /* restore EXR */
        mov.b   r1l,r1h
        mov.w   r1,@(USEREXR:16,er0)
        .endm
#endif


/* CPU context save/restore macros. */

        .macro  SAVE_ALL
        mov.l   er0,@-sp
        stc     ccr,r0l                         /* check kernel mode */
        btst    #4,r0l
        bne     5f

        /* user mode */
        mov.l   sp,@SYMBOL_NAME(sw_usp)
        mov.l   @sp,er0                         /* restore saved er0 */
        orc     #0x10,ccr                       /* switch kernel stack */
        mov.l   @SYMBOL_NAME(sw_ksp),sp
        sub.l   #(LRET-LORIG),sp                /* allocate LORIG - LRET */
        SAVEREGS
        mov.l   @SYMBOL_NAME(sw_usp),er0
        mov.l   @(USERRET:16,er0),er1           /* copy the RET addr */
        mov.l   er1,@(LRET-LER3:16,sp)
        SAVEEXR

        mov.l   @(LORIG-LER3:16,sp),er0
        mov.l   er0,@(LER0-LER3:16,sp)          /* copy ER0 */
        mov.w   e1,r1                           /* e1 highbyte = ccr */
        and     #0xef,r1h                       /* mask mode? flag */
        bra     6f
5:
        /* kernel mode */
        mov.l   @sp,er0                         /* restore saved er0 */
        subs    #2,sp                           /* set dummy ccr */
        SAVEREGS
        mov.w   @(LRET-LER3:16,sp),r1           /* copy old ccr */
6:
        mov.b   r1h,r1l
        mov.b   #0,r1h
        mov.w   r1,@(LCCR-LER3:16,sp)           /* set ccr */
        mov.l   er6,@-sp                        /* syscall arg #6 */
        mov.l   er5,@-sp                        /* syscall arg #5 */
        mov.l   er4,@-sp                        /* syscall arg #4 */
        .endm                                   /* r1 = ccr */

        .macro  RESTORE_ALL
        mov.l   @sp+,er4
        mov.l   @sp+,er5
        mov.l   @sp+,er6
        RESTOREREGS
        mov.w   @(LCCR-LER1:16,sp),r0           /* check kernel mode */
        btst    #4,r0l
        bne     7f

        orc     #0x80,ccr
        mov.l   @SYMBOL_NAME(sw_usp),er0
        mov.l   @(LER0-LER1:16,sp),er1          /* restore ER0 */
        mov.l   er1,@er0
        RESTOREEXR
        mov.w   @(LCCR-LER1:16,sp),r1           /* restore the RET addr */
        mov.b   r1l,r1h
        mov.b   @(LRET+1-LER1:16,sp),r1l
        mov.w   r1,e1
        mov.w   @(LRET+2-LER1:16,sp),r1
        mov.l   er1,@(USERRET:16,er0)

        mov.l   @sp+,er1
        add.l   #(LRET-LER1),sp                 /* remove LORIG - LRET */
        mov.l   sp,@SYMBOL_NAME(sw_ksp)
        andc    #0xef,ccr                       /* switch to user mode */
        mov.l   er0,sp
        bra     8f
7:
        mov.l   @sp+,er1
        adds    #4,sp
        adds    #2,sp
8:
        mov.l   @sp+,er0
        adds    #4,sp                           /* remove the sw created LVEC */
        rte
        .endm

.globl SYMBOL_NAME(system_call)
.globl SYMBOL_NAME(ret_from_exception)
.globl SYMBOL_NAME(ret_from_fork)
.globl SYMBOL_NAME(ret_from_interrupt)
.globl SYMBOL_NAME(interrupt_redirect_table)
.globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
.globl SYMBOL_NAME(resume)
.globl SYMBOL_NAME(interrupt_entry)
.globl SYMBOL_NAME(trace_break)

#if defined(CONFIG_ROMKERNEL)
        .section .int_redirect,"ax"
SYMBOL_NAME_LABEL(interrupt_redirect_table)
#if defined(CONFIG_CPU_H8300H)
        .rept   7
        .long   0
        .endr
#endif
#if defined(CONFIG_CPU_H8S)
        .rept   5
        .long   0
        .endr
        jmp     @SYMBOL_NAME(trace_break)
        .long   0
#endif

        jsr     @SYMBOL_NAME(interrupt_entry)   /* NMI */
        jmp     @SYMBOL_NAME(system_call)       /* TRAPA #0 (System call) */
        .long   0
        .long   0
        jmp     @SYMBOL_NAME(trace_break)       /* TRAPA #3 (breakpoint) */
        .rept   INTERRUPTS-12
        jsr     @SYMBOL_NAME(interrupt_entry)
        .endr
#endif
#if defined(CONFIG_RAMKERNEL)
.globl SYMBOL_NAME(interrupt_redirect_table)
        .section .bss
SYMBOL_NAME_LABEL(interrupt_redirect_table)
        .space  4
#endif

        .section .text
        .align  2
SYMBOL_NAME_LABEL(interrupt_entry)
        SAVE_ALL
        mov.l   sp,er0
        add.l   #LVEC,er0
        btst    #4,r1l
        bne     1f
        /* user LVEC */
        mov.l   @SYMBOL_NAME(sw_usp),er0
        adds    #4,er0
1:
        mov.l   @er0,er0                        /* LVEC address */
#if defined(CONFIG_ROMKERNEL)
        sub.l   #SYMBOL_NAME(interrupt_redirect_table),er0
#endif
#if defined(CONFIG_RAMKERNEL)
        mov.l   @SYMBOL_NAME(interrupt_redirect_table),er1
        sub.l   er1,er0
#endif
        SHLR2   er0
        dec.l   #1,er0
        mov.l   sp,er1
        subs    #4,er1                          /* adjust ret_pc */
        jsr     @SYMBOL_NAME(do_IRQ)
        jmp     @SYMBOL_NAME(ret_from_interrupt)

SYMBOL_NAME_LABEL(system_call)
        subs    #4,sp                           /* dummy LVEC */
        SAVE_ALL
        andc    #0x7f,ccr
        mov.l   er0,er4

        /* save top of frame */
        mov.l   sp,er0
        jsr     @SYMBOL_NAME(set_esp0)
        mov.l   sp,er2
        and.w   #0xe000,r2
        mov.b   @((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
        btst    #(TIF_SYSCALL_TRACE & 7),r2l
        beq     1f
        jsr     @SYMBOL_NAME(do_syscall_trace)
1:
        cmp.l   #NR_syscalls,er4
        bcc     badsys
        SHLL2   er4
        mov.l   #SYMBOL_NAME(sys_call_table),er0
        add.l   er4,er0
        mov.l   @er0,er4
        beq     SYMBOL_NAME(ret_from_exception):16
        mov.l   @(LER1:16,sp),er0
        mov.l   @(LER2:16,sp),er1
        mov.l   @(LER3:16,sp),er2
        jsr     @er4
        mov.l   er0,@(LER0:16,sp)               /* save the return value */
        mov.l   sp,er2
        and.w   #0xe000,r2
        mov.b   @((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
        btst    #(TIF_SYSCALL_TRACE & 7),r2l
        beq     2f
        jsr     @SYMBOL_NAME(do_syscall_trace)
2:
#if defined(CONFIG_SYSCALL_PRINT)
        jsr     @SYMBOL_NAME(syscall_print)
#endif
        orc     #0x80,ccr
        bra     resume_userspace

badsys:
        mov.l   #-ENOSYS,er0
        mov.l   er0,@(LER0:16,sp)
        bra     resume_userspace

#if !defined(CONFIG_PREEMPT)
#define resume_kernel restore_all
#endif

SYMBOL_NAME_LABEL(ret_from_exception)
#if defined(CONFIG_PREEMPT)
        orc     #0x80,ccr
#endif
SYMBOL_NAME_LABEL(ret_from_interrupt)
        mov.b   @(LCCR+1:16,sp),r0l
        btst    #4,r0l
        bne     resume_kernel:8         /* return from kernel */
resume_userspace:
        andc    #0x7f,ccr
        mov.l   sp,er4
        and.w   #0xe000,r4              /* er4 <- current thread info */
        mov.l   @(TI_FLAGS:16,er4),er1
        and.l   #_TIF_WORK_MASK,er1
        beq     restore_all:8
work_pending:
        btst    #TIF_NEED_RESCHED,r1l
        bne     work_resched:8
        /* work notifysig */
        mov.l   sp,er0
        subs    #4,er0                  /* er0: pt_regs */
        jsr     @SYMBOL_NAME(do_notify_resume)
        bra     restore_all:8
work_resched:
        mov.l   sp,er0
        jsr     @SYMBOL_NAME(set_esp0)
        jsr     @SYMBOL_NAME(schedule)
        bra     resume_userspace:8
restore_all:
        RESTORE_ALL                     /* Does RTE */

#if defined(CONFIG_PREEMPT)
resume_kernel:
        mov.l   @(TI_PRE_COUNT:16,er4),er0
        bne     restore_all:8
need_resched:
        mov.l   @(TI_FLAGS:16,er4),er0
        btst    #TIF_NEED_RESCHED,r0l
        beq     restore_all:8
        mov.b   @(LCCR+1:16,sp),r0l     /* Interrupt Enabled? */
        bmi     restore_all:8
        mov.l   #PREEMPT_ACTIVE,er0
        mov.l   er0,@(TI_PRE_COUNT:16,er4)
        andc    #0x7f,ccr
        mov.l   sp,er0
        jsr     @SYMBOL_NAME(set_esp0)
        jsr     @SYMBOL_NAME(schedule)
        orc     #0x80,ccr
        bra     need_resched:8
#endif

SYMBOL_NAME_LABEL(ret_from_fork)
        mov.l   er2,er0
        jsr     @SYMBOL_NAME(schedule_tail)
        jmp     @SYMBOL_NAME(ret_from_exception)

SYMBOL_NAME_LABEL(resume)
        /*
         * Beware - when entering resume, offset of tss is in d1,
         * prev (the current task) is in a0, next (the new task)
         * is in a1 and d2.b is non-zero if the mm structure is
         * shared between the tasks, so don't change these
         * registers until their contents are no longer needed.
         */

        /* save sr */
        sub.w   r3,r3
        stc     ccr,r3l
        mov.w   r3,@(THREAD_CCR+2:16,er0)

        /* disable interrupts */
        orc     #0x80,ccr
        mov.l   @SYMBOL_NAME(sw_usp),er3
        mov.l   er3,@(THREAD_USP:16,er0)
        mov.l   sp,@(THREAD_KSP:16,er0)

        /* Skip address space switching if they are the same. */
        /* FIXME: what did we hack out of here, this does nothing! */

        mov.l   @(THREAD_USP:16,er1),er0
        mov.l   er0,@SYMBOL_NAME(sw_usp)
        mov.l   @(THREAD_KSP:16,er1),sp

        /* restore status register */
        mov.w   @(THREAD_CCR+2:16,er1),r3

        ldc     r3l,ccr
        rts

SYMBOL_NAME_LABEL(trace_break)
        subs    #4,sp
        SAVE_ALL
        sub.l   er1,er1
        dec.l   #1,er1
        mov.l   er1,@(LORIG,sp)
        mov.l   sp,er0
        jsr     @SYMBOL_NAME(set_esp0)
        mov.l   @SYMBOL_NAME(sw_usp),er0
        mov.l   @er0,er1
        mov.w   @(-2:16,er1),r2
        cmp.w   #0x5730,r2
        beq     1f
        subs    #2,er1
        mov.l   er1,@er0
1:
        and.w   #0xff,e1
        mov.l   er1,er0
        jsr     @SYMBOL_NAME(trace_trap)
        jmp     @SYMBOL_NAME(ret_from_exception)

        .section        .bss
SYMBOL_NAME_LABEL(sw_ksp)
        .space  4
SYMBOL_NAME_LABEL(sw_usp)
        .space  4

        .end