sys/platform/vkernel/platform/copyio.c

   1 /*
   2  * Copyright (c) 2006 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/platform/vkernel/platform/copyio.c,v 1.9 2008/05/09 07:24:47 dillon Exp $
  35  */
  36
  37 #include <sys/types.h>
  38 #include <sys/systm.h>
  39 #include <sys/sfbuf.h>
  40 #include <vm/vm_page.h>
  41 #include <vm/vm_extern.h>
  42 #include <assert.h>
  43
  44 #include <sys/stat.h>
  45 #include <sys/mman.h>
  46
  47 #include <sys/mplock2.h>
  48
  49 /*
  50  * A bcopy that works dring low level boot, before FP is working
  51  */
  52 void
  53 ovbcopy(const void *src, void *dst, size_t len)
  54 {
  55         bcopy(src, dst, len);
  56 }
  57
  58 void
  59 bcopyi(const void *src, void *dst, size_t len)
  60 {
  61         bcopy(src, dst, len);
  62 }
  63
  64 int
  65 copystr(const void *kfaddr, void *kdaddr, size_t len, size_t *lencopied)
  66 {
  67         size_t i;
  68
  69         for (i = 0; i < len; ++i) {
  70                 if ((((char *)kdaddr)[i] = ((const char *)kfaddr)[i]) == 0) {
  71                         if (lencopied)
  72                                 *lencopied = i + 1;
  73                         return(0);
  74                 }
  75         }
  76         return (ENAMETOOLONG);
  77 }
  78
  79 /*
  80  * Copies a NUL-terminated string from user space to kernel space.
  81  * The number of bytes copied, including the terminator, is returned in
  82  * (*res).
  83  *
  84  * Returns 0 on success, EFAULT or ENAMETOOLONG on failure.
  85  */
  86 int
  87 copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *res)
  88 {
  89         int error;
  90         size_t n;
  91         const char *uptr = udaddr;
  92         char *kptr = kaddr;
  93
  94         if (res)
  95                 *res = 0;
  96         while (len) {
  97                 n = PAGE_SIZE - ((vm_offset_t)uptr & PAGE_MASK);
  98                 if (n > 32)
  99                         n = 32;
 100                 if (n > len)
 101                         n = len;
 102                 if ((error = copyin(uptr, kptr, n)) != 0)
 103                         return(error);
 104                 while (n) {
 105                         if (res)
 106                                 ++*res;
 107                         if (*kptr == 0)
 108                                 return(0);
 109                         ++kptr;
 110                         ++uptr;
 111                         --n;
 112                         --len;
 113                 }
 114
 115         }
 116         return(ENAMETOOLONG);
 117 }
 118
 119 /*
 120  * Copy a binary buffer from user space to kernel space.
 121  *
 122  * NOTE: on a real system copyin/copyout are MP safe, but the current
 123  * implementation on a vkernel is not so we get the mp lock.
 124  *
 125  * Returns 0 on success, EFAULT on failure.
 126  */
 127 int
 128 copyin(const void *udaddr, void *kaddr, size_t len)
 129 {
 130         struct vmspace *vm = curproc->p_vmspace;
 131         struct sf_buf *sf;
 132         vm_page_t m;
 133         int error;
 134         size_t n;
 135
 136         error = 0;
 137         get_mplock();
 138         while (len) {
 139                 m = vm_fault_page(&vm->vm_map, trunc_page((vm_offset_t)udaddr),
 140                                   VM_PROT_READ,
 141                                   VM_FAULT_NORMAL, &error);
 142                 if (error)
 143                         break;
 144                 n = PAGE_SIZE - ((vm_offset_t)udaddr & PAGE_MASK);
 145                 if (n > len)
 146                         n = len;
 147                 sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
 148                 bcopy((char *)sf_buf_kva(sf)+((vm_offset_t)udaddr & PAGE_MASK),
 149                       kaddr, n);
 150                 len -= n;
 151                 udaddr = (const char *)udaddr + n;
 152                 kaddr = (char *)kaddr + n;
 153                 vm_page_unhold(m);
 154                 sf_buf_free(sf);
 155         }
 156         rel_mplock();
 157         return (error);
 158 }
 159
 160 /*
 161  * Copy a binary buffer from kernel space to user space.
 162  *
 163  * Returns 0 on success, EFAULT on failure.
 164  */
 165 int
 166 copyout(const void *kaddr, void *udaddr, size_t len)
 167 {
 168         struct vmspace *vm = curproc->p_vmspace;
 169         struct sf_buf *sf;
 170         vm_page_t m;
 171         int error;
 172         size_t n;
 173
 174         error = 0;
 175         get_mplock();
 176         while (len) {
 177                 m = vm_fault_page(&vm->vm_map, trunc_page((vm_offset_t)udaddr),
 178                                   VM_PROT_READ|VM_PROT_WRITE,
 179                                   VM_FAULT_NORMAL, &error);
 180                 if (error)
 181                         break;
 182                 n = PAGE_SIZE - ((vm_offset_t)udaddr & PAGE_MASK);
 183                 if (n > len)
 184                         n = len;
 185                 sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
 186                 bcopy(kaddr, (char *)sf_buf_kva(sf) +
 187                              ((vm_offset_t)udaddr & PAGE_MASK), n);
 188                 len -= n;
 189                 udaddr = (char *)udaddr + n;
 190                 kaddr = (const char *)kaddr + n;
 191                 vm_page_dirty(m);
 192                 vm_page_unhold(m);
 193                 sf_buf_free(sf);
 194         }
 195         rel_mplock();
 196         return (error);
 197 }
 198
 199 /*
 200  * Fetch the byte at the specified user address.  Returns -1 on failure.
 201  */
 202 int
 203 fubyte(const void *base)
 204 {
 205         unsigned char c;
 206         int error;
 207
 208         if ((error = copyin(base, &c, 1)) == 0)
 209                 return((int)c);
 210         return(-1);
 211 }
 212
 213 /*
 214  * Store a byte at the specified user address.  Returns -1 on failure.
 215  */
 216 int
 217 subyte (void *base, int byte)
 218 {
 219         unsigned char c = byte;
 220         int error;
 221
 222         if ((error = copyout(&c, base, 1)) == 0)
 223                 return(0);
 224         return(-1);
 225 }
 226
 227 /*
 228  * Fetch a word (integer, 32 bits) from user space
 229  */
 230 long
 231 fuword(const void *base)
 232 {
 233         long v;
 234         int error;
 235
 236         if ((error = copyin(base, &v, sizeof(v))) == 0)
 237                 return((long)v);
 238         return(-1);
 239 }
 240
 241 /*
 242  * Store a word (integer, 32 bits) to user space
 243  */
 244 int
 245 suword(void *base, long word)
 246 {
 247         int error;
 248
 249         if ((error = copyout(&word, base, sizeof(word))) == 0)
 250                 return(0);
 251         return(-1);
 252 }
 253
 254 /*
 255  * Fetch an short word (16 bits) from user space
 256  */
 257 int
 258 fusword(void *base)
 259 {
 260         unsigned short sword;
 261         int error;
 262
 263         if ((error = copyin(base, &sword, sizeof(sword))) == 0)
 264                 return((int)sword);
 265         return(-1);
 266 }
 267
 268 /*
 269  * Store a short word (16 bits) to user space
 270  */
 271 int
 272 susword (void *base, int word)
 273 {
 274         unsigned short sword = word;
 275         int error;
 276
 277         if ((error = copyout(&sword, base, sizeof(sword))) == 0)
 278                 return(0);
 279         return(-1);
 280 }
 281