linux/arch/parisc/hpux/wrappers.S
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   1/*
   2 * Linux/PARISC Project (http://www.parisc-linux.org/)
   3 *
   4 * HP-UX System Call Wrapper routines and System Call Return Path
   5 *
   6 * Copyright (C) 2000 Hewlett-Packard (John Marvin)
   7 *
   8 *    This program is free software; you can redistribute it and/or modify
   9 *    it under the terms of the GNU General Public License as published by
  10 *    the Free Software Foundation; either version 2, or (at your option)
  11 *    any later version.
  12 *
  13 *    This program is distributed in the hope that it will be useful,
  14 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 *    GNU General Public License for more details.
  17 *
  18 *    You should have received a copy of the GNU General Public License
  19 *    along with this program; if not, write to the Free Software
  20 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23#ifdef CONFIG_64BIT
  24#warning PA64 support needs more work...did first cut
  25#endif
  26
  27#include <asm/asm-offsets.h>
  28#include <asm/assembly.h>
  29#include <asm/signal.h>
  30#include <linux/linkage.h>
  31
  32        .level  LEVEL
  33        .text
  34
  35        /* These should probably go in a header file somewhere.
  36         * They are duplicated in kernel/wrappers.S
  37         * Possibly we should consider consolidating these
  38         * register save/restore macros.
  39         */
  40        .macro  reg_save regs
  41#ifdef CONFIG_64BIT
  42#warning NEEDS WORK for 64-bit
  43#endif
  44        STREG   %r3, PT_GR3(\regs)
  45        STREG   %r4, PT_GR4(\regs)
  46        STREG   %r5, PT_GR5(\regs)
  47        STREG   %r6, PT_GR6(\regs)
  48        STREG   %r7, PT_GR7(\regs)
  49        STREG   %r8, PT_GR8(\regs)
  50        STREG   %r9, PT_GR9(\regs)
  51        STREG   %r10,PT_GR10(\regs)
  52        STREG   %r11,PT_GR11(\regs)
  53        STREG   %r12,PT_GR12(\regs)
  54        STREG   %r13,PT_GR13(\regs)
  55        STREG   %r14,PT_GR14(\regs)
  56        STREG   %r15,PT_GR15(\regs)
  57        STREG   %r16,PT_GR16(\regs)
  58        STREG   %r17,PT_GR17(\regs)
  59        STREG   %r18,PT_GR18(\regs)
  60        .endm
  61
  62        .macro  reg_restore regs
  63        LDREG   PT_GR3(\regs), %r3
  64        LDREG   PT_GR4(\regs), %r4
  65        LDREG   PT_GR5(\regs), %r5
  66        LDREG   PT_GR6(\regs), %r6
  67        LDREG   PT_GR7(\regs), %r7
  68        LDREG   PT_GR8(\regs), %r8
  69        LDREG   PT_GR9(\regs), %r9
  70        LDREG   PT_GR10(\regs),%r10
  71        LDREG   PT_GR11(\regs),%r11
  72        LDREG   PT_GR12(\regs),%r12
  73        LDREG   PT_GR13(\regs),%r13
  74        LDREG   PT_GR14(\regs),%r14
  75        LDREG   PT_GR15(\regs),%r15
  76        LDREG   PT_GR16(\regs),%r16
  77        LDREG   PT_GR17(\regs),%r17
  78        LDREG   PT_GR18(\regs),%r18
  79        .endm
  80
  81
  82        .import sys_fork
  83
  84ENTRY(hpux_fork_wrapper)
  85        ldo     TASK_REGS-TASK_SZ_ALGN-64(%r30),%r1         ;! get pt regs
  86                                                            ;! pointer in task
  87        reg_save %r1
  88
  89        STREG   %r2,-20(%r30)
  90        ldo     64(%r30),%r30
  91        STREG   %r2,PT_GR19(%r1)        ;! save for child
  92        STREG   %r30,PT_GR21(%r1)       ;! save for child
  93
  94        LDREG   PT_GR30(%r1),%r25
  95        mtctl   %r25,%cr29
  96        copy    %r1,%r24
  97        bl      sys_clone,%r2
  98        ldi     SIGCHLD,%r26
  99
 100        LDREG   -84(%r30),%r2
 101fork_return:
 102        ldo     -64(%r30),%r30
 103        ldo     TASK_REGS-TASK_SZ_ALGN-64(%r30),%r1         ;! get pt regs
 104
 105        reg_restore %r1
 106
 107        /*
 108         * HP-UX wants pid (child gets parent pid, parent gets child pid)
 109         * in r28 and a flag in r29 (r29 == 1 for child, 0 for parent).
 110         * Linux fork returns 0 for child, pid for parent. Since HP-UX
 111         * libc stub throws away parent pid and returns 0 for child,
 112         * we'll just return 0 for parent pid now. Only applications
 113         * that jump directly to the gateway page (not supported) will
 114         * know the difference. We can fix this later if necessary.
 115         */
 116
 117        ldo     -1024(%r0),%r1
 118        comb,>>=,n %r28,%r1,fork_exit  /* just let the syscall exit handle it */
 119        or,=    %r28,%r0,%r0
 120        or,tr   %r0,%r0,%r29    /* r28 <> 0, we are parent, set r29 to 0 */
 121        ldo     1(%r0),%r29     /* r28 == 0, we are child,  set r29 to 1 */
 122
 123fork_exit:
 124        bv      %r0(%r2)
 125        nop
 126ENDPROC(hpux_fork_wrapper)
 127
 128        /* Set the return value for the child */
 129
 130ENTRY(hpux_child_return)
 131#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
 132        bl,n    schedule_tail, %r2
 133#endif
 134
 135        LDREG   TASK_PT_GR19-TASK_SZ_ALGN-128(%r30),%r2
 136        b fork_return
 137        copy %r0,%r28
 138ENDPROC(hpux_child_return)
 139
 140        .import hpux_execve
 141
 142ENTRY(hpux_execv_wrapper)
 143        copy %r0,%r24  /* NULL environment */
 144
 145ENTRY(hpux_execve_wrapper)
 146
 147        ldo     TASK_REGS-TASK_SZ_ALGN-64(%r30),%r1         ;! get pt regs
 148
 149        /*
 150         * Do we need to save/restore r3-r18 here?
 151         * I don't think so. why would new thread need old
 152         * threads registers?
 153         */
 154
 155        /* Store arg0, arg1 and arg2 so that hpux_execve will find them */
 156
 157        STREG %r26,PT_GR26(%r1)
 158        STREG %r25,PT_GR25(%r1)
 159        STREG %r24,PT_GR24(%r1)
 160
 161        STREG %r2,-20(%r30)
 162        ldo 64(%r30),%r30
 163        bl hpux_execve,%r2
 164        copy %r1,%arg0
 165
 166        ldo -64(%r30),%r30
 167        LDREG   -20(%r30),%r2
 168
 169        /* If exec succeeded we need to load the args */
 170
 171        ldo -1024(%r0),%r1
 172        comb,>>= %r28,%r1,exec_error
 173        copy %r2,%r19
 174        ldo     -TASK_SZ_ALGN-64(%r30),%r1         ;! get task ptr
 175        LDREG   TASK_PT_GR26(%r1),%r26
 176        LDREG   TASK_PT_GR25(%r1),%r25
 177        LDREG   TASK_PT_GR24(%r1),%r24
 178        LDREG   TASK_PT_GR23(%r1),%r23
 179        copy %r0,%r2    /* Flag to syscall_exit not to clear args */
 180
 181exec_error:
 182        bv %r0(%r19)
 183        nop
 184ENDPROC(hpux_execv_wrapper)
 185
 186        .import hpux_pipe
 187
 188        /* HP-UX expects pipefd's returned in r28 & r29 */
 189
 190ENTRY(hpux_pipe_wrapper)
 191        STREG %r2,-20(%r30)
 192        ldo 64(%r30),%r30
 193        bl hpux_pipe,%r2
 194        ldo -56(%r30),%r26 /* pass local array to hpux_pipe */
 195
 196
 197        ldo -1024(%r0),%r1
 198        comb,>>= %r28,%r1,pipe_exit /* let syscall exit handle it */
 199        LDREG   -84(%r30),%r2
 200
 201        /* if success, load fd's from stack array */
 202
 203        LDREG   -56(%r30),%r28
 204        LDREG   -52(%r30),%r29
 205
 206pipe_exit:
 207        bv %r0(%r2)
 208        ldo -64(%r30),%r30
 209ENDPROC(hpux_pipe_wrapper)
 210
 211        .import syscall_exit
 212
 213ENTRY(hpux_syscall_exit)
 214        /*
 215         *
 216         * HP-UX call return conventions:
 217         *
 218         * if error:
 219         *       r22 = 1
 220         *       r28 = errno value
 221         *       r29 = secondary return value
 222         * else
 223         *       r22 = 0
 224         *       r28 = return value
 225         *       r29 = secondary return value
 226         *
 227         * For now, we'll just check to see if r28 is < (unsigned long)-1024
 228         * (to handle addresses > 2 Gb) and if so set r22 to zero. If not,
 229         * we'll complement r28 and set r22 to 1. Wrappers will be
 230         * needed for syscalls that care about the secondary return value.
 231         * The wrapper may also need a way of avoiding the following code,
 232         * but we'll deal with that when it becomes necessary.
 233         */
 234
 235        ldo -1024(%r0),%r1
 236        comb,<< %r28,%r1,no_error
 237        copy %r0,%r22
 238        subi 0,%r28,%r28
 239        ldo 1(%r0),%r22
 240
 241no_error:
 242        b,n syscall_exit
 243ENDPROC(hpux_syscall_exit)
 244
 245        .import hpux_unimplemented
 246
 247ENTRY(hpux_unimplemented_wrapper)
 248        b hpux_unimplemented
 249        STREG %r22,-64(%r30)  /* overwrite arg8 with syscall number */
 250ENDPROC(hpux_unimplemented_wrapper)
 251
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