arch/h8300/platform/h8300h/entry.S

   1 /* -*- mode: asm -*-
   2  *
   3  *  linux/arch/h8300/platform/h8300h/entry.S
   4  *
   5  *  Yoshinori Sato <ysato@users.sourceforge.jp>
   6  *  David McCullough <davidm@snapgear.com>
   7  *
   8  */
   9
  10 /*
  11  *  entry.S
  12  *  include exception/interrupt gateway
  13  *          system call entry
  14  */
  15
  16 #include <linux/sys.h>
  17 #include <linux/config.h>
  18 #include <asm/unistd.h>
  19 #include <asm/setup.h>
  20 #include <asm/segment.h>
  21 #include <asm/linkage.h>
  22 #include <asm/asm-offsets.h>
  23 #include <asm/thread_info.h>
  24 #include <asm/errno.h>
  25
  26         .h8300h
  27
  28 /* CPU context save/restore macros. */
  29
  30         .macro  SAVE_ALL
  31         mov.l   er0,@-sp
  32
  33         stc     ccr,r0l                         /* check kernel mode */
  34         orc     #0x10,ccr
  35         btst    #4,r0l
  36         bne     5f
  37
  38         mov.l   sp,@SYMBOL_NAME(sw_usp)         /* user mode */
  39         mov.l   @sp,er0
  40         mov.l   @SYMBOL_NAME(sw_ksp),sp
  41         sub.l   #(LRET-LORIG),sp                /* allocate LORIG - LRET */
  42         mov.l   er0,@-sp
  43         mov.l   er1,@-sp
  44         mov.l   @SYMBOL_NAME(sw_usp),er0
  45         mov.l   @(8:16,er0),er1                 /* copy the RET addr */
  46         mov.l   er1,@(LRET-LER1:16,sp)
  47
  48         mov.w   e1,r1                           /* e1 highbyte = ccr */
  49         and     #0xef,r1h                       /* mask mode? flag */
  50         sub.w   r0,r0
  51         mov.b   r1h,r0l
  52         mov.w   r0,@(LCCR-LER1:16,sp)           /* copy ccr */
  53         mov.l   @(LORIG-LER1:16,sp),er0
  54         mov.l   er0,@(LER0-LER1:16,sp)          /* copy ER0 */
  55         bra     6f
  56 5:
  57         mov.l   @sp,er0                         /* kernel mode */
  58         subs    #2,sp                           /* dummy ccr */
  59         mov.l   er0,@-sp
  60         mov.l   er1,@-sp
  61         mov.w   @(LRET-LER1:16,sp),r1           /* copy old ccr */
  62         mov.b   r1h,r1l
  63         mov.b   #0,r1h
  64         mov.w   r1,@(LCCR-LER1:16,sp)           /* set ccr */
  65 6:
  66         mov.l   er2,@-sp
  67         mov.l   er3,@-sp
  68         mov.l   er6,@-sp                        /* syscall arg #6 */
  69         mov.l   er5,@-sp                        /* syscall arg #5 */
  70         mov.l   er4,@-sp                        /* syscall arg #4 */
  71         .endm
  72
  73         .macro  RESTORE_ALL
  74         mov.l   @sp+,er4
  75         mov.l   @sp+,er5
  76         mov.l   @sp+,er6
  77         mov.l   @sp+,er3
  78         mov.l   @sp+,er2
  79         mov.w   @(LCCR-LER1:16,sp),r0           /* check kernel mode */
  80         btst    #4,r0l
  81         bne     7f
  82
  83         orc     #0x80,ccr
  84         mov.l   @SYMBOL_NAME(sw_usp),er0
  85         mov.l   @(LER0-LER1:16,sp),er1          /* restore ER0 */
  86         mov.l   er1,@er0
  87         mov.w   @(LCCR-LER1:16,sp),r1           /* restore the RET addr */
  88         mov.b   r1l,r1h
  89         mov.b   @(LRET+1-LER1:16,sp),r1l
  90         mov.w   r1,e1
  91         mov.w   @(LRET+2-LER1:16,sp),r1
  92         mov.l   er1,@(8:16,er0)
  93
  94         mov.l   @sp+,er1
  95         add.l   #(LRET-LER1),sp                 /* remove LORIG - LRET */
  96         mov.l   sp,@SYMBOL_NAME(sw_ksp)
  97         mov.l   er0,sp
  98         bra     8f
  99 7:
 100         mov.l   @sp+,er1
 101         adds    #4,sp
 102         adds    #2,sp
 103 8:
 104         mov.l   @sp+,er0
 105         adds    #4,sp                           /* remove the sw created LVEC */
 106         rte
 107         .endm
 108
 109 .globl SYMBOL_NAME(system_call)
 110 .globl SYMBOL_NAME(ret_from_exception)
 111 .globl SYMBOL_NAME(ret_from_fork)
 112 .globl SYMBOL_NAME(ret_from_interrupt)
 113 .globl SYMBOL_NAME(interrupt_redirect_table)
 114 .globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
 115 .globl SYMBOL_NAME(resume)
 116 .globl SYMBOL_NAME(interrupt_redirect_table)
 117 .globl SYMBOL_NAME(interrupt_entry)
 118 .globl SYMBOL_NAME(system_call)
 119 .globl SYMBOL_NAME(trace_break)
 120
 121 #if defined(CONFIG_ROMKERNEL)
 122 INTERRUPTS = 64
 123         .section .int_redirect,"ax"
 124 SYMBOL_NAME_LABEL(interrupt_redirect_table)
 125         .rept   7
 126         .long   0
 127         .endr
 128         jsr     @SYMBOL_NAME(interrupt_entry)   /* NMI */
 129         jmp     @SYMBOL_NAME(system_call)       /* TRAPA #0 (System call) */
 130         .long   0
 131         .long   0
 132         jmp     @SYMBOL_NAME(trace_break)       /* TRAPA #3 (breakpoint) */
 133         .rept   INTERRUPTS-12
 134         jsr     @SYMBOL_NAME(interrupt_entry)
 135         .endr
 136 #endif
 137 #if defined(CONFIG_RAMKERNEL)
 138 .globl SYMBOL_NAME(interrupt_redirect_table)
 139         .section .bss
 140 SYMBOL_NAME_LABEL(interrupt_redirect_table)
 141         .space  4
 142 #endif
 143
 144         .section .text
 145         .align  2
 146 SYMBOL_NAME_LABEL(interrupt_entry)
 147         SAVE_ALL
 148         mov.w   @(LCCR,sp),r0
 149         btst    #4,r0l
 150         bne     1f
 151         mov.l   @SYMBOL_NAME(sw_usp),er0
 152         mov.l   @(4:16,er0),er0
 153         bra     2f
 154 1:
 155         mov.l   @(LVEC,sp),er0
 156 2:
 157 #if defined(CONFIG_ROMKERNEL)
 158         sub.l   #SYMBOL_NAME(interrupt_redirect_table),er0
 159 #endif
 160 #if defined(CONFIG_RAMKERNEL)
 161         mov.l   @SYMBOL_NAME(interrupt_redirect_table),er1
 162         sub.l   er1,er0
 163 #endif
 164         shlr.l  er0
 165         shlr.l  er0
 166         dec.l   #1,er0
 167         mov.l   sp,er1
 168         subs    #4,er1                          /* adjust ret_pc */
 169         jsr     @SYMBOL_NAME(process_int)
 170         mov.l   @SYMBOL_NAME(irq_stat)+CPUSTAT_SOFTIRQ_PENDING,er0
 171         beq     1f
 172         jsr     @SYMBOL_NAME(do_softirq)
 173 1:
 174         jmp     @SYMBOL_NAME(ret_from_interrupt)
 175
 176 SYMBOL_NAME_LABEL(system_call)
 177         subs    #4,sp                           /* dummy LVEC */
 178         SAVE_ALL
 179         mov.w   @(LCCR:16,sp),r1
 180         bset    #4,r1l
 181         ldc     r1l,ccr
 182         mov.l   er0,er4
 183         mov.l   #-ENOSYS,er0
 184         mov.l   er0,@(LER0:16,sp)
 185
 186         /* save top of frame */
 187         mov.l   sp,er0
 188         jsr     @SYMBOL_NAME(set_esp0)
 189         cmp.l   #NR_syscalls,er4
 190         bcc     SYMBOL_NAME(ret_from_exception):16
 191         shll.l  er4
 192         shll.l  er4
 193         mov.l   #SYMBOL_NAME(sys_call_table),er0
 194         add.l   er4,er0
 195         mov.l   @er0,er4
 196         beq     SYMBOL_NAME(ret_from_exception):16
 197         mov.l   sp,er2
 198         and.w   #0xe000,r2
 199         mov.b   @((TASK_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
 200         btst    #(TIF_SYSCALL_TRACE & 7),r2l
 201         bne     1f
 202         mov.l   @(LER1:16,sp),er0
 203         mov.l   @(LER2:16,sp),er1
 204         mov.l   @(LER3:16,sp),er2
 205         jsr     @er4
 206         mov.l   er0,@(LER0:16,sp)               /* save the return value */
 207 #if defined(CONFIG_SYSCALL_PRINT)
 208         jsr     @SYMBOL_NAME(syscall_print)
 209 #endif
 210         bra     SYMBOL_NAME(ret_from_exception):8
 211 1:
 212         jsr     SYMBOL_NAME(syscall_trace)
 213         mov.l   @(LER1:16,sp),er0
 214         mov.l   @(LER2:16,sp),er1
 215         mov.l   @(LER3:16,sp),er2
 216         jsr     @er4
 217         mov.l   er0,@(LER0:16,sp)               /* save the return value */
 218         jsr     @SYMBOL_NAME(syscall_trace)
 219         bra     SYMBOL_NAME(ret_from_exception):8
 220
 221 SYMBOL_NAME_LABEL(ret_from_fork)
 222         mov.l   er2,er0
 223         jsr     @SYMBOL_NAME(schedule_tail)
 224         bra     SYMBOL_NAME(ret_from_exception):8
 225
 226 SYMBOL_NAME_LABEL(reschedule)
 227         /* save top of frame */
 228         mov.l   sp,er0
 229         jsr     @SYMBOL_NAME(set_esp0)
 230         jsr     @SYMBOL_NAME(schedule)
 231
 232 SYMBOL_NAME_LABEL(ret_from_exception)
 233 #if defined(CONFIG_PREEMPT)
 234         orc     #0x80,ccr
 235 #endif
 236 SYMBOL_NAME_LABEL(ret_from_interrupt)
 237         mov.b   @(LCCR+1:16,sp),r0l
 238         btst    #4,r0l                  /* check if returning to kernel */
 239         bne     done:8                  /* if so, skip resched, signals */
 240         andc    #0x7f,ccr
 241         mov.l   sp,er4
 242         and.w   #0xe000,r4
 243         mov.l   @(TI_FLAGS:16,er4),er1
 244         and.l   #_TIF_WORK_MASK,er1
 245         beq     done:8
 246 1:
 247         mov.l   @(TI_FLAGS:16,er4),er1
 248         btst    #TIF_NEED_RESCHED,r1l
 249         bne     SYMBOL_NAME(reschedule):16
 250         mov.l   sp,er0
 251         subs    #4,er0                  /* adjust retpc */
 252         mov.l   er2,er1
 253         jsr     @SYMBOL_NAME(do_signal)
 254 #if defined(CONFIG_PREEMPT)
 255         bra     done:8                  /* userspace thoru */
 256 3:
 257         btst    #4,r0l
 258         beq     done:8                  /* userspace thoru */
 259 4:
 260         mov.l   @(TI_PRE_COUNT:16,er4),er1
 261         bne     done:8
 262         mov.l   @(TI_FLAGS:16,er4),er1
 263         btst    #TIF_NEED_RESCHED,r1l
 264         beq     done:8
 265         mov.b   r0l,r0l
 266         bpl     done:8                  /* interrupt off (exception path?) */
 267         mov.l   #PREEMPT_ACTIVE,er1
 268         mov.l   er1,@(TI_PRE_COUNT:16,er4)
 269         andc    #0x7f,ccr
 270         jsr     @SYMBOL_NAME(schedule)
 271         sub.l   er1,er1
 272         mov.l   er1,@(TI_PRE_COUNT:16,er4)
 273         orc     #0x80,ccr
 274         bra     4b:8
 275 #endif
 276 done:
 277         RESTORE_ALL                     /* Does RTE */
 278
 279 SYMBOL_NAME_LABEL(resume)
 280         /*
 281          * Beware - when entering resume, offset of tss is in d1,
 282          * prev (the current task) is in a0, next (the new task)
 283          * is in a1 and d2.b is non-zero if the mm structure is
 284          * shared between the tasks, so don't change these
 285          * registers until their contents are no longer needed.
 286          */
 287
 288         /* save sr */
 289         sub.w   r3,r3
 290         stc     ccr,r3l
 291         mov.w   r3,@(THREAD_CCR+2:16,er0)
 292
 293         /* disable interrupts */
 294         orc     #0x80,ccr
 295         mov.l   @SYMBOL_NAME(sw_usp),er3
 296         mov.l   er3,@(THREAD_USP:16,er0)
 297         mov.l   sp,@(THREAD_KSP:16,er0)
 298
 299         /* Skip address space switching if they are the same. */
 300         /* FIXME: what did we hack out of here, this does nothing! */
 301
 302         mov.l   @(THREAD_USP:16,er1),er0
 303         mov.l   er0,@SYMBOL_NAME(sw_usp)
 304         mov.l   @(THREAD_KSP:16,er1),sp
 305
 306         /* restore status register */
 307         mov.w   @(THREAD_CCR+2:16,er1),r3
 308
 309         ldc     r3l,ccr
 310         rts
 311
 312 SYMBOL_NAME_LABEL(trace_break)
 313         subs    #4,sp
 314         SAVE_ALL
 315         sub.l   er1,er1
 316         dec.l   #1,er1
 317         mov.l   er1,@(LORIG,sp)
 318         mov.l   sp,er0
 319         jsr     @SYMBOL_NAME(set_esp0)
 320         mov.l   @SYMBOL_NAME(sw_usp),er0
 321         mov.l   @er0,er1
 322         subs    #2,er1
 323         mov.l   er1,@er0
 324         and.w   #0xff,e1
 325         mov.l   er1,er0
 326         jsr     @SYMBOL_NAME(trace_trap)
 327         jmp     @SYMBOL_NAME(ret_from_exception)
 328
 329         .section        .bss
 330 SYMBOL_NAME_LABEL(sw_ksp)
 331         .space  4
 332 SYMBOL_NAME_LABEL(sw_usp)
 333         .space  4