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

     /*-
      * SPDX-License-Identifier: BSD-3-Clause
      *
      * Copyright (c) 1988 University of Utah.
      * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
      * All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * the Systems Programming Group of the University of Utah Computer
     * Science Department, and code derived from software contributed to
     * Berkeley by William Jolitz.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      from: Utah $Hdr: mem.c 1.13 89/10/08$
     *      from: @(#)mem.c 7.2 (Berkeley) 5/9/91
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    /*
     * Memory special file
     */
    
    #include <sys/param.h>
    #include <sys/conf.h>
    #include <sys/fcntl.h>
    #include <sys/ioccom.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/malloc.h>
    #include <sys/memrange.h>
    #include <sys/module.h>
    #include <sys/mutex.h>
    #include <sys/proc.h>
    #include <sys/signalvar.h>
    #include <sys/sx.h>
    #include <sys/systm.h>
    #include <sys/uio.h>
    
    #include <vm/vm.h>
    #include <vm/vm_param.h>
    #include <vm/vm_page.h>
    #include <vm/vm_phys.h>
    #include <vm/vm_dumpset.h>
    #include <vm/pmap.h>
    #include <vm/vm_extern.h>
    
    #include <machine/memdev.h>
    
    /*
     * Used in /dev/mem drivers and elsewhere
     */
    MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors");
    
    struct mem_range_softc mem_range_softc;
    
    static struct sx tmppt_lock;
    SX_SYSINIT(tmppt, &tmppt_lock, "mem4map");
    
    /* ARGSUSED */
    int
    memrw(struct cdev *dev, struct uio *uio, int flags)
    {
            int o;
            u_int c = 0, v;
            struct iovec *iov;
            int error = 0;
            vm_offset_t addr, eaddr;
    
            while (uio->uio_resid > 0 && error == 0) {
                    iov = uio->uio_iov;
                    if (iov->iov_len == 0) {
                            uio->uio_iov++;
                            uio->uio_iovcnt--;
                            if (uio->uio_iovcnt < 0)
                                   panic("memrw");
                           continue;
                   }
                   if (dev2unit(dev) == CDEV_MINOR_MEM) {
                           int i;
                           int address_valid = 0;
   
                           v = uio->uio_offset;
                           v &= ~PAGE_MASK;
                           for (i = 0; dump_avail[i] || dump_avail[i + 1];
                           i += 2) {
                                   if (v >= dump_avail[i] &&
                                       v < dump_avail[i + 1]) {
                                           address_valid = 1;
                                           break;
                                   }
                           }
                           if (!address_valid)
                                   return (EINVAL);
                           sx_xlock(&tmppt_lock);
                           pmap_kenter((vm_offset_t)_tmppt, v);
                           pmap_tlb_flush(kernel_pmap, (vm_offset_t)_tmppt);
                           o = (int)uio->uio_offset & PAGE_MASK;
                           c = (u_int)(PAGE_SIZE - ((int)iov->iov_base & PAGE_MASK));
                           c = min(c, (u_int)(PAGE_SIZE - o));
                           c = min(c, (u_int)iov->iov_len);
                           error = uiomove((caddr_t)&_tmppt[o], (int)c, uio);
                           pmap_qremove((vm_offset_t)_tmppt, 1);
                           sx_xunlock(&tmppt_lock);
                           continue;
                   }
                   else if (dev2unit(dev) == CDEV_MINOR_KMEM) {
                           c = iov->iov_len;
   
                           /*
                            * Make sure that all of the pages are currently
                            * resident so that we don't create any zero-fill
                            * pages.
                            */
                           addr = trunc_page(uio->uio_offset);
                           eaddr = round_page(uio->uio_offset + c);
   
                           for (; addr < eaddr; addr += PAGE_SIZE)
                                   if (pmap_extract(kernel_pmap, addr) == 0)
                                           return (EFAULT);
                           if (!kernacc((caddr_t)(int)uio->uio_offset, c,
                               uio->uio_rw == UIO_READ ?
                               VM_PROT_READ : VM_PROT_WRITE))
                                           return (EFAULT);
                           error = uiomove((caddr_t)(int)uio->uio_offset, (int)c, uio);
                           continue;
                   }
                   /* else panic! */
           }
           return (error);
   }
   
   /*
    * allow user processes to MMAP some memory sections
    * instead of going through read/write
    */
   /* ARGSUSED */
   
   int
   memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
       int prot __unused, vm_memattr_t *memattr __unused)
   {
           if (dev2unit(dev) == CDEV_MINOR_MEM) {
                   *paddr = offset;
                   return (0);
           }
           return (-1);
   }
   
   int
   memioctl_md(struct cdev *dev __unused, u_long cmd __unused,
       caddr_t data __unused, int flags __unused, struct thread *td __unused)
   {
           return (ENOTTY);
   }

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