mem.c

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    1 /*-
    2  * Copyright (c) 1988 University of Utah.
    3  * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
    4  * All rights reserved.
    5  *
    6  * This code is derived from software contributed to Berkeley by
    7  * the Systems Programming Group of the University of Utah Computer
    8  * Science Department, and code derived from software contributed to
    9  * Berkeley by William Jolitz.
   10  *
   11  * Redistribution and use in source and binary forms, with or without
   12  * modification, are permitted provided that the following conditions
   13  * are met:
   14  * 1. Redistributions of source code must retain the above copyright
   15  *    notice, this list of conditions and the following disclaimer.
   16  * 2. Redistributions in binary form must reproduce the above copyright
   17  *    notice, this list of conditions and the following disclaimer in the
   18  *    documentation and/or other materials provided with the distribution.
   19  * 4. Neither the name of the University nor the names of its contributors
   20  *    may be used to endorse or promote products derived from this software
   21  *    without specific prior written permission.
   22  *
   23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   33  * SUCH DAMAGE.
   34  *
   35  *      from: Utah $Hdr: mem.c 1.13 89/10/08$
   36  *      from: @(#)mem.c 7.2 (Berkeley) 5/9/91
   37  */
   38 
   39 #include <sys/cdefs.h>
   40 __FBSDID("$FreeBSD$");
   41 
   42 /*
   43  * Memory special file
   44  */
   45 
   46 #include <sys/param.h>
   47 #include <sys/conf.h>
   48 #include <sys/fcntl.h>
   49 #include <sys/ioccom.h>
   50 #include <sys/kernel.h>
   51 #include <sys/lock.h>
   52 #include <sys/malloc.h>
   53 #include <sys/memrange.h>
   54 #include <sys/module.h>
   55 #include <sys/mutex.h>
   56 #include <sys/proc.h>
   57 #include <sys/signalvar.h>
   58 #include <sys/systm.h>
   59 #include <sys/uio.h>
   60 
   61 #include <machine/specialreg.h>
   62 #include <machine/vmparam.h>
   63 
   64 #include <vm/vm.h>
   65 #include <vm/pmap.h>
   66 #include <vm/vm_extern.h>
   67 
   68 #include <machine/memdev.h>
   69 
   70 /*
   71  * Used in /dev/mem drivers and elsewhere
   72  */
   73 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
   74 
   75 /* ARGSUSED */
   76 int
   77 memrw(struct cdev *dev, struct uio *uio, int flags)
   78 {
   79         struct iovec *iov;
   80         u_long c, v;
   81         int error, o, sflags;
   82         vm_offset_t addr, eaddr;
   83 
   84         GIANT_REQUIRED;
   85 
   86         error = 0;
   87         c = 0;
   88         sflags = curthread_pflags_set(TDP_DEVMEMIO);
   89         while (uio->uio_resid > 0 && error == 0) {
   90                 iov = uio->uio_iov;
   91                 if (iov->iov_len == 0) {
   92                         uio->uio_iov++;
   93                         uio->uio_iovcnt--;
   94                         if (uio->uio_iovcnt < 0)
   95                                 panic("memrw");
   96                         continue;
   97                 }
   98                 if (dev2unit(dev) == CDEV_MINOR_MEM) {
   99                         v = uio->uio_offset;
  100 kmemphys:
  101                         o = v & PAGE_MASK;
  102                         c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o));
  103                         v = PHYS_TO_DMAP(v);
  104                         if (v < DMAP_MIN_ADDRESS ||
  105                             (v > DMAP_MIN_ADDRESS + dmaplimit &&
  106                             v <= DMAP_MAX_ADDRESS) ||
  107                             pmap_kextract(v) == 0) {
  108                                 error = EFAULT;
  109                                 goto ret;
  110                         }
  111                         error = uiomove((void *)v, (int)c, uio);
  112                         continue;
  113                 }
  114                 else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
  115                         v = uio->uio_offset;
  116 
  117                         if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) {
  118                                 v = DMAP_TO_PHYS(v);
  119                                 goto kmemphys;
  120                         }
  121 
  122                         c = iov->iov_len;
  123 
  124                         /*
  125                          * Make sure that all of the pages are currently
  126                          * resident so that we don't create any zero-fill
  127                          * pages.
  128                          */
  129                         addr = trunc_page(v);
  130                         eaddr = round_page(v + c);
  131 
  132                         if (addr < VM_MIN_KERNEL_ADDRESS) {
  133                                 error = EFAULT;
  134                                 goto ret;
  135                         }
  136                         for (; addr < eaddr; addr += PAGE_SIZE) {
  137                                 if (pmap_extract(kernel_pmap, addr) == 0) {
  138                                         error = EFAULT;
  139                                         goto ret;
  140                                 }
  141                         }
  142                         if (!kernacc((caddr_t)(long)v, c,
  143                             uio->uio_rw == UIO_READ ? 
  144                             VM_PROT_READ : VM_PROT_WRITE)) {
  145                                 error = EFAULT;
  146                                 goto ret;
  147                         }
  148 
  149                         error = uiomove((caddr_t)(long)v, (int)c, uio);
  150                         continue;
  151                 }
  152                 /* else panic! */
  153         }
  154 ret:
  155         curthread_pflags_restore(sflags);
  156         return (error);
  157 }
  158 
  159 /*
  160  * allow user processes to MMAP some memory sections
  161  * instead of going through read/write
  162  */
  163 /* ARGSUSED */
  164 int
  165 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
  166     int prot __unused, vm_memattr_t *memattr __unused)
  167 {
  168         if (dev2unit(dev) == CDEV_MINOR_MEM)
  169                 *paddr = offset;
  170         else if (dev2unit(dev) == CDEV_MINOR_KMEM)
  171                 *paddr = vtophys(offset);
  172         /* else panic! */
  173         return (0);
  174 }
  175 
  176 /*
  177  * Operations for changing memory attributes.
  178  *
  179  * This is basically just an ioctl shim for mem_range_attr_get
  180  * and mem_range_attr_set.
  181  */
  182 /* ARGSUSED */
  183 int 
  184 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags,
  185     struct thread *td)
  186 {
  187         int nd, error = 0;
  188         struct mem_range_op *mo = (struct mem_range_op *)data;
  189         struct mem_range_desc *md;
  190         
  191         /* is this for us? */
  192         if ((cmd != MEMRANGE_GET) &&
  193             (cmd != MEMRANGE_SET))
  194                 return (ENOTTY);
  195 
  196         /* any chance we can handle this? */
  197         if (mem_range_softc.mr_op == NULL)
  198                 return (EOPNOTSUPP);
  199 
  200         /* do we have any descriptors? */
  201         if (mem_range_softc.mr_ndesc == 0)
  202                 return (ENXIO);
  203 
  204         switch (cmd) {
  205         case MEMRANGE_GET:
  206                 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc);
  207                 if (nd > 0) {
  208                         md = (struct mem_range_desc *)
  209                                 malloc(nd * sizeof(struct mem_range_desc),
  210                                        M_MEMDESC, M_WAITOK);
  211                         error = mem_range_attr_get(md, &nd);
  212                         if (!error)
  213                                 error = copyout(md, mo->mo_desc, 
  214                                         nd * sizeof(struct mem_range_desc));
  215                         free(md, M_MEMDESC);
  216                 }
  217                 else
  218                         nd = mem_range_softc.mr_ndesc;
  219                 mo->mo_arg[0] = nd;
  220                 break;
  221                 
  222         case MEMRANGE_SET:
  223                 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc),
  224                                                     M_MEMDESC, M_WAITOK);
  225                 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc));
  226                 /* clamp description string */
  227                 md->mr_owner[sizeof(md->mr_owner) - 1] = 0;
  228                 if (error == 0)
  229                         error = mem_range_attr_set(md, &mo->mo_arg[0]);
  230                 free(md, M_MEMDESC);
  231                 break;
  232         }
  233         return (error);
  234 }

Cache object: 40700c4edc3a16582fde582ed8f7645e

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FreeBSD/Linux Kernel Cross Reference sys/amd64/amd64/mem.c

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sys/amd64/amd64/mem.c