arch/h8300/kernel/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 <asm/unistd.h>
  18 #include <asm/setup.h>
  19 #include <asm/segment.h>
  20 #include <asm/linkage.h>
  21 #include <asm/asm-offsets.h>
  22 #include <asm/thread_info.h>
  23 #include <asm/errno.h>
  24
  25 #if defined(CONFIG_CPU_H8300H)
  26 #define USERRET 8
  27 INTERRUPTS = 64
  28         .h8300h
  29         .macro  SHLL2 reg
  30         shll.l  \reg
  31         shll.l  \reg
  32         .endm
  33         .macro  SHLR2 reg
  34         shlr.l  \reg
  35         shlr.l  \reg
  36         .endm
  37         .macro  SAVEREGS
  38         mov.l   er0,@-sp
  39         mov.l   er1,@-sp
  40         mov.l   er2,@-sp
  41         mov.l   er3,@-sp
  42         .endm
  43         .macro  RESTOREREGS
  44         mov.l   @sp+,er3
  45         mov.l   @sp+,er2
  46         .endm
  47         .macro  SAVEEXR
  48         .endm
  49         .macro  RESTOREEXR
  50         .endm
  51 #endif
  52 #if defined(CONFIG_CPU_H8S)
  53 #define USERRET 10
  54 #define USEREXR 8
  55 INTERRUPTS = 128
  56         .h8300s
  57         .macro  SHLL2 reg
  58         shll.l  #2,\reg
  59         .endm
  60         .macro  SHLR2 reg
  61         shlr.l  #2,\reg
  62         .endm
  63         .macro  SAVEREGS
  64         stm.l   er0-er3,@-sp
  65         .endm
  66         .macro  RESTOREREGS
  67         ldm.l   @sp+,er2-er3
  68         .endm
  69         .macro  SAVEEXR
  70         mov.w   @(USEREXR:16,er0),r1
  71         mov.w   r1,@(LEXR-LER3:16,sp)           /* copy EXR */
  72         .endm
  73         .macro  RESTOREEXR
  74         mov.w   @(LEXR-LER1:16,sp),r1           /* restore EXR */
  75         mov.b   r1l,r1h
  76         mov.w   r1,@(USEREXR:16,er0)
  77         .endm
  78 #endif
  79
  80
  81 /* CPU context save/restore macros. */
  82
  83         .macro  SAVE_ALL
  84         mov.l   er0,@-sp
  85         stc     ccr,r0l                         /* check kernel mode */
  86         btst    #4,r0l
  87         bne     5f
  88
  89         /* user mode */
  90         mov.l   sp,@SYMBOL_NAME(sw_usp)
  91         mov.l   @sp,er0                         /* restore saved er0 */
  92         orc     #0x10,ccr                       /* switch kernel stack */
  93         mov.l   @SYMBOL_NAME(sw_ksp),sp
  94         sub.l   #(LRET-LORIG),sp                /* allocate LORIG - LRET */
  95         SAVEREGS
  96         mov.l   @SYMBOL_NAME(sw_usp),er0
  97         mov.l   @(USERRET:16,er0),er1           /* copy the RET addr */
  98         mov.l   er1,@(LRET-LER3:16,sp)
  99         SAVEEXR
 100
 101         mov.l   @(LORIG-LER3:16,sp),er0
 102         mov.l   er0,@(LER0-LER3:16,sp)          /* copy ER0 */
 103         mov.w   e1,r1                           /* e1 highbyte = ccr */
 104         and     #0xef,r1h                       /* mask mode? flag */
 105         bra     6f
 106 5:
 107         /* kernel mode */
 108         mov.l   @sp,er0                         /* restore saved er0 */
 109         subs    #2,sp                           /* set dummy ccr */
 110         SAVEREGS
 111         mov.w   @(LRET-LER3:16,sp),r1           /* copy old ccr */
 112 6:
 113         mov.b   r1h,r1l
 114         mov.b   #0,r1h
 115         mov.w   r1,@(LCCR-LER3:16,sp)           /* set ccr */
 116         mov.l   er6,@-sp                        /* syscall arg #6 */
 117         mov.l   er5,@-sp                        /* syscall arg #5 */
 118         mov.l   er4,@-sp                        /* syscall arg #4 */
 119         .endm                                   /* r1 = ccr */
 120
 121         .macro  RESTORE_ALL
 122         mov.l   @sp+,er4
 123         mov.l   @sp+,er5
 124         mov.l   @sp+,er6
 125         RESTOREREGS
 126         mov.w   @(LCCR-LER1:16,sp),r0           /* check kernel mode */
 127         btst    #4,r0l
 128         bne     7f
 129
 130         orc     #0x80,ccr
 131         mov.l   @SYMBOL_NAME(sw_usp),er0
 132         mov.l   @(LER0-LER1:16,sp),er1          /* restore ER0 */
 133         mov.l   er1,@er0
 134         RESTOREEXR
 135         mov.w   @(LCCR-LER1:16,sp),r1           /* restore the RET addr */
 136         mov.b   r1l,r1h
 137         mov.b   @(LRET+1-LER1:16,sp),r1l
 138         mov.w   r1,e1
 139         mov.w   @(LRET+2-LER1:16,sp),r1
 140         mov.l   er1,@(USERRET:16,er0)
 141
 142         mov.l   @sp+,er1
 143         add.l   #(LRET-LER1),sp                 /* remove LORIG - LRET */
 144         mov.l   sp,@SYMBOL_NAME(sw_ksp)
 145         andc    #0xef,ccr                       /* switch to user mode */
 146         mov.l   er0,sp
 147         bra     8f
 148 7:
 149         mov.l   @sp+,er1
 150         adds    #4,sp
 151         adds    #2,sp
 152 8:
 153         mov.l   @sp+,er0
 154         adds    #4,sp                           /* remove the sw created LVEC */
 155         rte
 156         .endm
 157
 158 .globl SYMBOL_NAME(system_call)
 159 .globl SYMBOL_NAME(ret_from_exception)
 160 .globl SYMBOL_NAME(ret_from_fork)
 161 .globl SYMBOL_NAME(ret_from_interrupt)
 162 .globl SYMBOL_NAME(interrupt_redirect_table)
 163 .globl SYMBOL_NAME(sw_ksp),SYMBOL_NAME(sw_usp)
 164 .globl SYMBOL_NAME(resume)
 165 .globl SYMBOL_NAME(interrupt_entry)
 166 .globl SYMBOL_NAME(trace_break)
 167
 168 #if defined(CONFIG_ROMKERNEL)
 169         .section .int_redirect,"ax"
 170 SYMBOL_NAME_LABEL(interrupt_redirect_table)
 171 #if defined(CONFIG_CPU_H8300H)
 172         .rept   7
 173         .long   0
 174         .endr
 175 #endif
 176 #if defined(CONFIG_CPU_H8S)
 177         .rept   5
 178         .long   0
 179         .endr
 180         jmp     @SYMBOL_NAME(trace_break)
 181         .long   0
 182 #endif
 183
 184         jsr     @SYMBOL_NAME(interrupt_entry)   /* NMI */
 185         jmp     @SYMBOL_NAME(system_call)       /* TRAPA #0 (System call) */
 186         .long   0
 187         .long   0
 188         jmp     @SYMBOL_NAME(trace_break)       /* TRAPA #3 (breakpoint) */
 189         .rept   INTERRUPTS-12
 190         jsr     @SYMBOL_NAME(interrupt_entry)
 191         .endr
 192 #endif
 193 #if defined(CONFIG_RAMKERNEL)
 194 .globl SYMBOL_NAME(interrupt_redirect_table)
 195         .section .bss
 196 SYMBOL_NAME_LABEL(interrupt_redirect_table)
 197         .space  4
 198 #endif
 199
 200         .section .text
 201         .align  2
 202 SYMBOL_NAME_LABEL(interrupt_entry)
 203         SAVE_ALL
 204         mov.l   sp,er0
 205         add.l   #LVEC,er0
 206         btst    #4,r1l
 207         bne     1f
 208         /* user LVEC */
 209         mov.l   @SYMBOL_NAME(sw_usp),er0
 210         adds    #4,er0
 211 1:
 212         mov.l   @er0,er0                        /* LVEC address */
 213 #if defined(CONFIG_ROMKERNEL)
 214         sub.l   #SYMBOL_NAME(interrupt_redirect_table),er0
 215 #endif
 216 #if defined(CONFIG_RAMKERNEL)
 217         mov.l   @SYMBOL_NAME(interrupt_redirect_table),er1
 218         sub.l   er1,er0
 219 #endif
 220         SHLR2   er0
 221         dec.l   #1,er0
 222         mov.l   sp,er1
 223         subs    #4,er1                          /* adjust ret_pc */
 224         jsr     @SYMBOL_NAME(do_IRQ)
 225         jmp     @SYMBOL_NAME(ret_from_interrupt)
 226
 227 SYMBOL_NAME_LABEL(system_call)
 228         subs    #4,sp                           /* dummy LVEC */
 229         SAVE_ALL
 230         andc    #0x7f,ccr
 231         mov.l   er0,er4
 232
 233         /* save top of frame */
 234         mov.l   sp,er0
 235         jsr     @SYMBOL_NAME(set_esp0)
 236         mov.l   sp,er2
 237         and.w   #0xe000,r2
 238         mov.b   @((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
 239         btst    #(TIF_SYSCALL_TRACE & 7),r2l
 240         beq     1f
 241         jsr     @SYMBOL_NAME(do_syscall_trace)
 242 1:
 243         cmp.l   #NR_syscalls,er4
 244         bcc     badsys
 245         SHLL2   er4
 246         mov.l   #SYMBOL_NAME(sys_call_table),er0
 247         add.l   er4,er0
 248         mov.l   @er0,er4
 249         beq     SYMBOL_NAME(ret_from_exception):16
 250         mov.l   @(LER1:16,sp),er0
 251         mov.l   @(LER2:16,sp),er1
 252         mov.l   @(LER3:16,sp),er2
 253         jsr     @er4
 254         mov.l   er0,@(LER0:16,sp)               /* save the return value */
 255         mov.l   sp,er2
 256         and.w   #0xe000,r2
 257         mov.b   @((TI_FLAGS+3-(TIF_SYSCALL_TRACE >> 3)):16,er2),r2l
 258         btst    #(TIF_SYSCALL_TRACE & 7),r2l
 259         beq     2f
 260         jsr     @SYMBOL_NAME(do_syscall_trace)
 261 2:
 262 #if defined(CONFIG_SYSCALL_PRINT)
 263         jsr     @SYMBOL_NAME(syscall_print)
 264 #endif
 265         orc     #0x80,ccr
 266         bra     resume_userspace
 267
 268 badsys:
 269         mov.l   #-ENOSYS,er0
 270         mov.l   er0,@(LER0:16,sp)
 271         bra     resume_userspace
 272
 273 #if !defined(CONFIG_PREEMPT)
 274 #define resume_kernel restore_all
 275 #endif
 276
 277 SYMBOL_NAME_LABEL(ret_from_exception)
 278 #if defined(CONFIG_PREEMPT)
 279         orc     #0x80,ccr
 280 #endif
 281 SYMBOL_NAME_LABEL(ret_from_interrupt)
 282         mov.b   @(LCCR+1:16,sp),r0l
 283         btst    #4,r0l
 284         bne     resume_kernel:8         /* return from kernel */
 285 resume_userspace:
 286         andc    #0x7f,ccr
 287         mov.l   sp,er4
 288         and.w   #0xe000,r4              /* er4 <- current thread info */
 289         mov.l   @(TI_FLAGS:16,er4),er1
 290         and.l   #_TIF_WORK_MASK,er1
 291         beq     restore_all:8
 292 work_pending:
 293         btst    #TIF_NEED_RESCHED,r1l
 294         bne     work_resched:8
 295         /* work notifysig */
 296         mov.l   sp,er0
 297         subs    #4,er0                  /* er0: pt_regs */
 298         jsr     @SYMBOL_NAME(do_notify_resume)
 299         bra     restore_all:8
 300 work_resched:
 301         mov.l   sp,er0
 302         jsr     @SYMBOL_NAME(set_esp0)
 303         jsr     @SYMBOL_NAME(schedule)
 304         bra     resume_userspace:8
 305 restore_all:
 306         RESTORE_ALL                     /* Does RTE */
 307
 308 #if defined(CONFIG_PREEMPT)
 309 resume_kernel:
 310         mov.l   @(TI_PRE_COUNT:16,er4),er0
 311         bne     restore_all:8
 312 need_resched:
 313         mov.l   @(TI_FLAGS:16,er4),er0
 314         btst    #TIF_NEED_RESCHED,r0l
 315         beq     restore_all:8
 316         mov.b   @(LCCR+1:16,sp),r0l     /* Interrupt Enabled? */
 317         bmi     restore_all:8
 318         mov.l   #PREEMPT_ACTIVE,er0
 319         mov.l   er0,@(TI_PRE_COUNT:16,er4)
 320         andc    #0x7f,ccr
 321         mov.l   sp,er0
 322         jsr     @SYMBOL_NAME(set_esp0)
 323         jsr     @SYMBOL_NAME(schedule)
 324         orc     #0x80,ccr
 325         bra     need_resched:8
 326 #endif
 327
 328 SYMBOL_NAME_LABEL(ret_from_fork)
 329         mov.l   er2,er0
 330         jsr     @SYMBOL_NAME(schedule_tail)
 331         jmp     @SYMBOL_NAME(ret_from_exception)
 332
 333 SYMBOL_NAME_LABEL(resume)
 334         /*
 335          * Beware - when entering resume, offset of tss is in d1,
 336          * prev (the current task) is in a0, next (the new task)
 337          * is in a1 and d2.b is non-zero if the mm structure is
 338          * shared between the tasks, so don't change these
 339          * registers until their contents are no longer needed.
 340          */
 341
 342         /* save sr */
 343         sub.w   r3,r3
 344         stc     ccr,r3l
 345         mov.w   r3,@(THREAD_CCR+2:16,er0)
 346
 347         /* disable interrupts */
 348         orc     #0x80,ccr
 349         mov.l   @SYMBOL_NAME(sw_usp),er3
 350         mov.l   er3,@(THREAD_USP:16,er0)
 351         mov.l   sp,@(THREAD_KSP:16,er0)
 352
 353         /* Skip address space switching if they are the same. */
 354         /* FIXME: what did we hack out of here, this does nothing! */
 355
 356         mov.l   @(THREAD_USP:16,er1),er0
 357         mov.l   er0,@SYMBOL_NAME(sw_usp)
 358         mov.l   @(THREAD_KSP:16,er1),sp
 359
 360         /* restore status register */
 361         mov.w   @(THREAD_CCR+2:16,er1),r3
 362
 363         ldc     r3l,ccr
 364         rts
 365
 366 SYMBOL_NAME_LABEL(trace_break)
 367         subs    #4,sp
 368         SAVE_ALL
 369         sub.l   er1,er1
 370         dec.l   #1,er1
 371         mov.l   er1,@(LORIG,sp)
 372         mov.l   sp,er0
 373         jsr     @SYMBOL_NAME(set_esp0)
 374         mov.l   @SYMBOL_NAME(sw_usp),er0
 375         mov.l   @er0,er1
 376         mov.w   @(-2:16,er1),r2
 377         cmp.w   #0x5730,r2
 378         beq     1f
 379         subs    #2,er1
 380         mov.l   er1,@er0
 381 1:
 382         and.w   #0xff,e1
 383         mov.l   er1,er0
 384         jsr     @SYMBOL_NAME(trace_trap)
 385         jmp     @SYMBOL_NAME(ret_from_exception)
 386
 387         .section        .bss
 388 SYMBOL_NAME_LABEL(sw_ksp)
 389         .space  4
 390 SYMBOL_NAME_LABEL(sw_usp)
 391         .space  4
 392
 393         .end