sys/arch/powerpc/ibm4xx/copyinstr.c

   1 /*      $NetBSD: copyinstr.c,v 1.7 2005/12/11 12:18:42 christos Exp $   */
   2
   3 /*
   4  * Copyright 2001 Wasabi Systems, Inc.
   5  * All rights reserved.
   6  *
   7  * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. All advertising materials mentioning features or use of this software
  18  *    must display the following acknowledgement:
  19  *      This product includes software developed for the NetBSD Project by
  20  *      Wasabi Systems, Inc.
  21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
  22  *    or promote products derived from this software without specific prior
  23  *    written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
  29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include <sys/cdefs.h>
  39 __KERNEL_RCSID(0, "$NetBSD: copyinstr.c,v 1.7 2005/12/11 12:18:42 christos Exp $");
  40
  41 #include <sys/param.h>
  42 #include <uvm/uvm_extern.h>
  43 #include <machine/pcb.h>
  44
  45 int
  46 copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
  47 {
  48         struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
  49         int msr, pid, tmp, ctx;
  50         struct faultbuf env;
  51
  52         if (setfault(&env)) {
  53                 curpcb->pcb_onfault = 0;
  54                 /* XXXX -- len may be lost on a fault */
  55                 if (done)
  56                         *done = len;
  57                 return EFAULT;
  58         }
  59
  60         if (!(ctx = pm->pm_ctx)) {
  61                 /* No context -- assign it one */
  62                 ctx_alloc(pm);
  63                 ctx = pm->pm_ctx;
  64         }
  65
  66         if (len) {
  67                 __asm volatile("mtctr %3;"              /* Set up counter */
  68                         "mfmsr %0;"                     /* Save MSR */
  69                         "li %1,0x20; "
  70                         "andc %1,%0,%1; mtmsr %1;"      /* Disable IMMU */
  71                         "mfpid %1;"                     /* Save old PID */
  72                         "sync; isync;"
  73
  74                         "li %3,0;"                      /* Clear len */
  75
  76                         "1: "
  77                         "mtpid %4; sync;"               /* Load user ctx */
  78                         "lbz %2,0(%5); addi %5,%5,1;"   /* Load byte */
  79                         "sync; isync;"
  80                         "mtpid %1;sync;"
  81                         "stb %2,0(%6);  dcbf 0,%6; addi %6,%6,1;"       /* Store kernel byte */
  82                         "sync; isync;"
  83                         "addi %3,%3,1;"                 /* Inc len */
  84                         "or. %2,%2,%2;"
  85                         "bdnzf 2,1b;"                   /*
  86                                                          * while(ctr-- && !zero)
  87                                                          */
  88
  89                         "mtpid %1; mtmsr %0;"           /* Restore PID, MSR */
  90                         "sync; isync;"
  91                         : "=&r" (msr), "=&r" (pid), "=&r" (tmp), "+b" (len)
  92                         : "r" (ctx), "b" (udaddr), "b" (kaddr));
  93         }
  94         curpcb->pcb_onfault = 0;
  95         if (done)
  96                 *done = len;
  97         return 0;
  98 }