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

     /*-
      * 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.
     * 4. 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: releng/6.4/sys/powerpc/powerpc/mem.c 133855 2004-08-16 13:07:40Z ssouhlal $");
    
    /*
     * Memory special file
     */
    
    #include <sys/param.h>
    #include <sys/conf.h>
    #include <sys/fcntl.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/msgbuf.h>
    #include <sys/systm.h>
    #include <sys/signalvar.h>
    #include <sys/uio.h>
    
    #include <machine/md_var.h>
    #include <machine/ofw_machdep.h>
    #include <machine/vmparam.h>
    
    #include <vm/vm.h>
    #include <vm/pmap.h>
    #include <vm/vm_extern.h>
    
    #include <machine/memdev.h>
    
    struct mem_range_softc mem_range_softc;
    
    /* ARGSUSED */
    int
    memrw(struct cdev *dev, struct uio *uio, int flags)
    {
            struct iovec *iov;
            int error = 0;
            vm_offset_t va, eva, off, v;
            vm_prot_t prot;
            vm_size_t cnt;
    
            cnt = 0;
            error = 0;
    
            GIANT_REQUIRED;
    
            while (uio->uio_resid > 0 && !error) {
                    iov = uio->uio_iov;
                    if (iov->iov_len == 0) {
                            uio->uio_iov++;
                            uio->uio_iovcnt--;
                            if (uio->uio_iovcnt < 0)
                                    panic("memrw");
                            continue;
                    }
                    if (minor(dev) == CDEV_MINOR_MEM) {
    kmem_direct_mapped:     v = uio->uio_offset;
    
                           off = uio->uio_offset & PAGE_MASK;
                           cnt = PAGE_SIZE - ((vm_offset_t)iov->iov_base &
                               PAGE_MASK);
                           cnt = min(cnt, PAGE_SIZE - off);
                           cnt = min(cnt, iov->iov_len);
   
                           if (mem_valid(v, cnt)
                               && pmap_dev_direct_mapped(v, cnt)) {
                                   error = EFAULT;
                                   break;
                           }
   
                           uiomove((void *)v, cnt, uio);
                           break;
                   }
                   else if (minor(dev) == CDEV_MINOR_KMEM) {
                           va = uio->uio_offset;
   
                           if ((va < VM_MIN_KERNEL_ADDRESS)
                               || (va > VM_MAX_KERNEL_ADDRESS))
                                   goto kmem_direct_mapped;
   
                           va = trunc_page(uio->uio_offset);
                           eva = round_page(uio->uio_offset
                               + iov->iov_len);
   
                           /* 
                            * Make sure that all the pages are currently resident
                            * so that we don't create any zero-fill pages.
                            */
   
                           for (; va < eva; va += PAGE_SIZE)
                                   if (pmap_extract(kernel_pmap, va)
                                       == 0)
                                           return (EFAULT);
   
                           prot = (uio->uio_rw == UIO_READ)
                               ? VM_PROT_READ : VM_PROT_WRITE;
   
                           va = uio->uio_offset;
                           if (kernacc((void *) va, iov->iov_len, prot)
                               == FALSE)
                                   return (EFAULT);
   
                           error = uiomove((void *)va, iov->iov_len, uio);
   
                           continue;
                   }
           }
   
           return (error);
   }
   
   /*
    * allow user processes to MMAP some memory sections
    * instead of going through read/write
    */
   int
   memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int prot)
   {
           /*
            * /dev/mem is the only one that makes sense through this
            * interface.  For /dev/kmem any physaddr we return here
            * could be transient and hence incorrect or invalid at
            * a later time.
            */
           if (minor(dev) != CDEV_MINOR_MEM)
                   return (-1);
   
           /* Only direct-mapped addresses. */
           if (mem_valid(offset, 0)
               && pmap_dev_direct_mapped(offset, 0))
                   return (EFAULT);
   
           *paddr = offset;
   
           return (0);
   }
   
   void
   dev_mem_md_init(void)
   {
   }

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