bsd/dev/ppc/systemcalls.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1997 Apple Computer, Inc.
  24  *
  25  * PowerPC Family:      System Call handlers.
  26  *
  27  * HISTORY
  28  * 27-July-97  A. Ramesh
  29  *      Adopted for Common Core.
  30  */
  31
  32 #include <mach/mach_types.h>
  33 #include <mach/error.h>
  34
  35 #include <kern/syscall_sw.h>
  36 #include <kern/kdp.h>
  37
  38 #include <machdep/ppc/frame.h>
  39 #include <machdep/ppc/thread.h>
  40 #include <machdep/ppc/asm.h>
  41 #include <machdep/ppc/proc_reg.h>
  42 #include <machdep/ppc/trap.h>
  43 #include <machdep/ppc/exception.h>
  44
  45
  46 #define ERESTART        -1              /* restart syscall */
  47 #define EJUSTRETURN     -2              /* don't modify regs, just return */
  48
  49
  50 struct unix_syscallargs {
  51         int flavor;
  52         int r3;
  53         int arg1, arg2,arg3,arg4,arg5,arg6,arg7,arg8,arg9;
  54 };
  55 extern struct sysent {          /* system call table */
  56         int16_t         sy_narg;        /* number of args */
  57         int16_t         sy_parallel;/* can execute in parallel */
  58         int32_t         (*sy_call)();   /* implementing function */
  59 } sysent[];
  60
  61 /*
  62 ** Function:    unix_syscall
  63 **
  64 ** Inputs:      pcb     - pointer to Process Control Block
  65 **              arg1    - arguments to mach system calls
  66 **              arg2
  67 **              arg3
  68 **              arg4
  69 **              arg5
  70 **              arg6
  71 **              arg7
  72 **
  73 ** Outputs:     none
  74 */
  75 void
  76 unix_syscall(
  77     struct pcb * pcb,
  78     int arg1,
  79     int arg2,
  80     int arg3,
  81     int arg4,
  82     int arg5,
  83     int arg6,
  84     int arg7
  85     )
  86 {
  87     struct ppc_saved_state      *regs;
  88     thread_t                    thread;
  89     struct proc                 *p;
  90    struct sysent                *callp;
  91     int                         nargs, error;
  92     unsigned short              code;
  93     int                         rval[2];
  94         struct unix_syscallargs sarg;
  95
  96     if (!USERMODE(pcb->ss.srr1))
  97         panic("unix_syscall");
  98
  99     regs = &pcb->ss;
 100     thread = current_thread();
 101
 102
 103     /*
 104     ** Get index into sysent table
 105     */
 106     code = regs->r0;
 107
 108
 109         /*
 110         ** Set up call pointer
 111         */
 112         callp = (code >= nsysent) ? &sysent[63] : &sysent[code];
 113
 114         sarg. flavor = (callp == sysent): 1: 0;
 115         sarg. r3 = regs->r3;
 116         sarg. arg1 = arg1;
 117         sarg. arg2 = arg2;
 118         sarg. arg3 = arg3;
 119         sarg. arg4 = arg4;
 120         sarg. arg5 = arg5;
 121         sarg. arg6 = arg6;
 122         sarg. arg7 = arg7;
 123
 124     set_bsduthreadargs(thread,pcb,&sarg);
 125
 126
 127         if (callp->sy_narg > 8)
 128         panic("unix_syscall: max arg count exceeded");
 129
 130         rval[0] = 0;
 131
 132         /* r4 is volatile, if we set it to regs->r4 here the child
 133          * will have parents r4 after execve */
 134         rval[1] = 0;
 135
 136         error = 0; /* Start with a good value */
 137
 138         /*
 139         ** the PPC runtime calls cerror after every unix system call, so
 140         ** assume no error and adjust the "pc" to skip this call.
 141         ** It will be set back to the cerror call if an error is detected.
 142         */
 143         regs->srr0 += 4;
 144         vt = get_bsduthreadarg(thread);
 145         p = ((struct proc *)get_bsdtask_info(current_task()));
 146         error = (*(callp->sy_call))(p, (caddr_t)vt, rval);
 147
 148     if (error == ERESTART) {
 149         regs->srr0 -= 8;
 150     }
 151     else if (error != EJUSTRETURN) {
 152         if (error)
 153         {
 154             regs->r3 = error;
 155             /* set the "pc" to execute cerror routine */
 156             regs->srr0 -= 4;
 157         } else { /* (not error) */
 158             regs->r3 = rval[0];
 159             regs->r4 = rval[1];
 160         }
 161     }
 162     /* else  (error == EJUSTRETURN) { nothing } */
 163
 164     thread_exception_return();
 165     /* NOTREACHED */
 166
 167 }
 168