arch/h8300/platform/h8s/entry.S

   1 /* -*- mode: asm -*-
   2  *
   3  *  linux/arch/h8300/platform/h8s/entry.S
   4  *
   5  *  Yoshinori Sato <ysato@users.sourceforge.jp>
   6  *
   7  *      fairly heavy changes to fix syscall args and signal processing
   8  *      by David McCullough <davidm@snapgear.com>
   9  */
  10
  11 /*
  12  *  entry.S
  13  *  include exception/interrupt gateway
  14  *          system call entry
  15  */
  16
  17 #include <linux/sys.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         .h8300s
  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         btst    #4,r0l
  35         bne     5f
  36
  37         /* user mode */
  38         mov.l   sp,@SYMBOL_NAME(sw_usp)
  39         mov.l   @sp,er0                         /* restore saved er0 */
  40         orc     #0x10,ccr                       /* switch kernel stack */
  41         mov.l   @SYMBOL_NAME(sw_ksp),sp
  42         sub.l   #(LRET-LORIG),sp                /* allocate LORIG - LRET */
  43         stm.l   er0-er3,@-sp
  44         mov.l   @SYMBOL_NAME(sw_usp),er0
  45         mov.l   @(10:16,er0),er1                /* copy the RET addr */
  46         mov.l   er1,@(LRET-LER3:16,sp)
  47         mov.w   @(8:16,er0),r1
  48         mov.w   r1,@(LEXR-LER3:16,sp)           /* copy EXR */
  49
  50         mov.w   e1,r1                           /* e1 highbyte = ccr */
  51         and     #0xef,r1h                       /* mask mode? flag */
  52         sub.w   r0,r0
  53         mov.b   r1h,r0l
  54         mov.w   r0,@(LCCR-LER3:16,sp)           /* copy ccr */
  55         mov.l   @(LORIG-LER3:16,sp),er0
  56         mov.l   er0,@(LER0-LER3:16,sp)          /* copy ER0 */
  57         bra     6f
  58 5:
  59         /* kernel mode */
  60         mov.l   @sp,er0                         /* restore saved er0 */
  61         subs    #2,sp                           /* set dummy ccr */
  62         stm.l   er0-er3,@-sp
  63         mov.w   @(LRET-LER3:16,sp),r1           /* copy old ccr */
  64         mov.b   r1h,r1l
  65         mov.b   #0,r1h
  66         mov.w   r1,@(LCCR-LER3:16,sp)
  67 6:
  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         ldm.l   @sp+,er2-er3
  78         mov.w   @(LCCR-LER1:16,sp),r0           /* check kernel mode */
  79         btst    #4,r0l
  80         bne     7f
  81
  82         orc     #0x80,ccr
  83         mov.l   @SYMBOL_NAME(sw_usp),er0
  84         mov.l   @(LER0-LER1:16,sp),er1          /* restore ER0 */
  85         mov.l   er1,@er0
  86         mov.w   @(LEXR-LER1:16,sp),r1           /* restore EXR */
  87         mov.b   r1l,r1h
  88         mov.w   r1,@(8:16,er0)
  89         mov.w   @(LCCR-LER1:16,sp),r1           /* restore the RET addr */
  90         mov.b   r1l,r1h
  91         mov.b   @(LRET+1-LER1:16,sp),r1l
  92         mov.w   r1,e1
  93         mov.w   @(LRET+2-LER1:16,sp),r1
  94         mov.l   er1,@(10:16,er0)
  95
  96         mov.l   @sp+,er1
  97         add.l   #(LRET-LER1),sp                 /* remove LORIG - LRET */
  98         mov.l   sp,@SYMBOL_NAME(sw_ksp)
  99         andc    #0xef,ccr                       /* switch to user mode */
 100         mov.l   er0,sp
 101         bra     8f
 102 7:
 103         mov.l   @sp+,er1
 104         adds    #4,sp
 105         adds    #2,sp
 106 8:
 107         mov.l   @sp+,er0
 108         adds    #4,sp                           /* remove the sw created LVEC */
 109         rte
 110         .endm
 111
 112 .globl SYMBOL_NAME(system_call)
 113 .globl SYMBOL_NAME(ret_from_exception)
 114 .globl SYMBOL_NAME(ret_from_fork)
 115 .globl SYMBOL_NAME(ret_from_interrupt)
 116 .globl SYMBOL_NAME(interrupt_redirect_table)
 117 .globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
 118 .globl SYMBOL_NAME(resume)
 119 .globl SYMBOL_NAME(trace_break)
 120 .globl SYMBOL_NAME(interrupt_entry)
 121
 122 INTERRUPTS = 128
 123 #if defined(CONFIG_ROMKERNEL)
 124         .section .int_redirect,"ax"
 125 SYMBOL_NAME_LABEL(interrupt_redirect_table)
 126         .rept   7
 127         .long   0
 128         .endr
 129         jsr     @SYMBOL_NAME(interrupt_entry)   /* NMI */
 130         jmp     @SYMBOL_NAME(system_call)       /* TRAPA #0 (System call) */
 131         .long   0
 132         .long   0
 133         jmp     @SYMBOL_NAME(trace_break)       /* TRAPA #3 (breakpoint) */
 134         .rept   INTERRUPTS-12
 135         jsr     @SYMBOL_NAME(interrupt_entry)
 136         .endr
 137 #endif
 138 #if defined(CONFIG_RAMKERNEL)
 139 .globl SYMBOL_NAME(interrupt_redirect_table)
 140         .section .bss
 141 SYMBOL_NAME_LABEL(interrupt_redirect_table)
 142         .space  4
 143 #endif
 144
 145         .section .text
 146         .align  2
 147 SYMBOL_NAME_LABEL(interrupt_entry)
 148         SAVE_ALL
 149         mov.w   @(LCCR,sp),r0
 150         btst    #4,r0l
 151         bne     1f
 152         mov.l   @SYMBOL_NAME(sw_usp),er0
 153         mov.l   @(4:16,er0),er0
 154         bra     2f
 155 1:
 156         mov.l   @(LVEC:16,sp),er0
 157 2:
 158 #if defined(CONFIG_ROMKERNEL)
 159         sub.l   #SYMBOL_NAME(interrupt_redirect_table),er0
 160 #endif
 161 #if defined(CONFIG_RAMKERNEL)
 162         mov.l   @SYMBOL_NAME(interrupt_redirect_table),er1
 163         sub.l   er1,er0
 164 #endif
 165         shlr.l  #2,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_exception)
 175
 176 SYMBOL_NAME_LABEL(system_call)
 177         subs    #4,sp                           /* dummy LVEC */
 178         SAVE_ALL
 179         mov.l   er0,er4
 180         mov.l   #-ENOSYS,er0
 181         mov.l   er0,@(LER0:16,sp)
 182
 183         /* save top of frame */
 184         mov.l   sp,er0
 185         jsr     @SYMBOL_NAME(set_esp0)
 186         cmp.l   #NR_syscalls,er4
 187         bcc     SYMBOL_NAME(ret_from_exception):16
 188         shll.l  #2,er4
 189         mov.l   #SYMBOL_NAME(sys_call_table),er0
 190         add.l   er4,er0
 191         mov.l   @er0,er0
 192         mov.l   er0,er4
 193         beq     SYMBOL_NAME(ret_from_exception):16
 194         mov.l   sp,er2
 195         and.w   #0xe000,r2
 196         mov.b   @((TASK_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
 197         btst    #(TIF_SYSCALL_TRACE & 7),r2l
 198         mov.l   @(LER1:16,sp),er0
 199         mov.l   @(LER2:16,sp),er1
 200         mov.l   @(LER3:16,sp),er2
 201         andc    #0x7f,ccr
 202         jsr     @er4
 203         mov.l   er0,@(LER0:16,sp)                       /* save the return value */
 204 #if defined(CONFIG_SYSCALL_PRINT)
 205         jsr     @SYMBOL_NAME(syscall_print)
 206 #endif
 207         bra     SYMBOL_NAME(ret_from_exception):8
 208 1:
 209         jsr     SYMBOL_NAME(syscall_trace)
 210         mov.l   @(LER1:16,sp),er0
 211         mov.l   @(LER2:16,sp),er1
 212         mov.l   @(LER3:16,sp),er2
 213         jsr     @er4
 214         mov.l   er0,@(LER0:16,sp)               /* save the return value */
 215         jsr     @SYMBOL_NAME(syscall_trace)
 216         bra     SYMBOL_NAME(ret_from_exception):8
 217
 218 SYMBOL_NAME_LABEL(ret_from_fork)
 219         mov.l   er2,er0
 220         jsr     @SYMBOL_NAME(schedule_tail)
 221         bra     SYMBOL_NAME(ret_from_exception):8
 222
 223 SYMBOL_NAME_LABEL(reschedule)
 224         /* save top of frame */
 225         mov.l   sp,er0
 226         jsr     @SYMBOL_NAME(set_esp0)
 227         jsr     @SYMBOL_NAME(schedule)
 228
 229 SYMBOL_NAME_LABEL(ret_from_exception)
 230 #if defined(CONFIG_PREEMPT)
 231         orc     #0x80,ccr
 232 #endif
 233 SYMBOL_NAME_LABEL(ret_from_interrupt)
 234         mov.b   @(LCCR+1:16,sp),r0l
 235         btst    #4,r0l                  /* check if returning to kernel */
 236         bne     done:8                  /* if so, skip resched, signals */
 237         andc    #0x7f,ccr
 238         mov.l   sp,er4
 239         and.w   #0xe000,r4
 240         mov.l   @(TI_FLAGS:16,er4),er1
 241         and.l   #_TIF_WORK_MASK,er1
 242         beq     done:8
 243 1:
 244         mov.l   @(TI_FLAGS:16,er4),er1
 245         btst    #TIF_NEED_RESCHED,r1l
 246         bne     SYMBOL_NAME(reschedule):16
 247         mov.l   sp,er0
 248         subs    #4,er0                  /* adjust retpc */
 249         mov.l   er2,er1
 250         jsr     @SYMBOL_NAME(do_signal)
 251 #if defined(CONFIG_PREEMPT)
 252         bra     done:8                  /* userspace thoru */
 253 3:
 254         btst    #4,r0l
 255         beq     done:8                  /* userspace thoru */
 256 4:
 257         mov.l   @(TI_PRE_COUNT:16,er4),er1
 258         bne     done:8
 259         mov.l   @(TI_FLAGS:16,er4),er1
 260         btst    #TIF_NEED_RESCHED,r1l
 261         beq     done:8
 262         mov.b   r0l,r0l
 263         bpl     done:8                  /* interrupt off (exception path?) */
 264         mov.l   #PREEMPT_ACTIVE,er1
 265         mov.l   er1,@(TI_PRE_COUNT:16,er4)
 266         andc    #0x7f,ccr
 267         jsr     @SYMBOL_NAME(schedule)
 268         sub.l   er1,er1
 269         mov.l   er1,@(TI_PRE_COUNT:16,er4)
 270         orc     #0x80,ccr
 271         bra     4b:8
 272 #endif
 273 done:
 274         RESTORE_ALL                     /* Does RTE */
 275
 276 SYMBOL_NAME_LABEL(resume)
 277         /*
 278          *      er0 = prev
 279          *      er1 = next
 280          *      return last in er2
 281          */
 282
 283         /* save sr */
 284         sub.w   r3,r3
 285         stc     ccr,r3l
 286         stc     exr,r3h
 287         mov.w   r3,@(THREAD_CCR+2:16,er0)
 288
 289         /* disable interrupts */
 290         orc     #0x80,ccr
 291         mov.l   @SYMBOL_NAME(sw_usp),er3
 292         mov.l   er3,@(THREAD_USP:16,er0)
 293         mov.l   sp,@(THREAD_KSP:16,er0)
 294
 295         /* Skip address space switching if they are the same. */
 296         /* FIXME: what did we hack out of here, this does nothing! */
 297
 298         mov.l   @(THREAD_USP:16,er1),er0
 299         mov.l   er0,@SYMBOL_NAME(sw_usp)
 300         mov.l   @(THREAD_KSP:16,er1),sp
 301
 302         /* restore status register */
 303         mov.w   @(THREAD_CCR+2:16,er1),r3
 304
 305         ldc     r3l,ccr
 306         ldc     r3h,exr
 307
 308         rts
 309
 310 SYMBOL_NAME_LABEL(trace_break)
 311         subs    #4,sp                   /* dummy LVEC */
 312         SAVE_ALL
 313         sub.l   er1,er1
 314         dec.l   #1,er1
 315         mov.l   er1,@(LORIG,sp)
 316         mov.l   sp,er0
 317         jsr     @SYMBOL_NAME(set_esp0)
 318         mov.l   @SYMBOL_NAME(sw_usp),er0
 319         mov.l   @er0,er1
 320         subs    #2,er1
 321         mov.l   er1,@er0
 322         and.w   #0xff,e1
 323         mov.l   er1,er0
 324         jsr     @SYMBOL_NAME(trace_trap)
 325         jmp     @SYMBOL_NAME(ret_from_exception)
 326
 327         .section        .bss
 328 SYMBOL_NAME_LABEL(sw_ksp)
 329         .space  4
 330 SYMBOL_NAME_LABEL(sw_usp)
 331         .space  4