date and time created 83/05/27 14:02:47 by sam

[unix-history] / usr / src / sys / kern / kern_subr.c

/*      kern_subr.c     4.1     83/05/27        */

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/uio.h"

uiomove(cp, n, rw, uio)
       register caddr_t cp;
       register int n;
       enum uio_rw rw;
       register struct uio *uio;
{
       register struct iovec *iov;
       u_int cnt;
       int error = 0;

       while (n > 0 && uio->uio_resid) {
               iov = uio->uio_iov;
               cnt = iov->iov_len;
               if (cnt == 0) {
                       uio->uio_iov++;
                       uio->uio_iovcnt--;
                       continue;
               }
               if (cnt > n)
                       cnt = n;
               switch (uio->uio_segflg) {

               case 0:
               case 2:
                       if (rw == UIO_READ)
                               error = copyout(cp, iov->iov_base, cnt);
                       else
                               error = copyin(iov->iov_base, cp, cnt);
                       if (error)
                               return (error);
                       break;

               case 1:
                       if (rw == UIO_READ)
                               bcopy((caddr_t)cp, iov->iov_base, cnt);
                       else
                               bcopy(iov->iov_base, (caddr_t)cp, cnt);
                       break;
               }
               iov->iov_base += cnt;
               iov->iov_len -= cnt;
               uio->uio_resid -= cnt;
               uio->uio_offset += cnt;
               cp += cnt;
               n -= cnt;
       }
       return (error);
}

/*
* Give next character to user as result of read.
*/
ureadc(c, uio)
       register int c;
       register struct uio *uio;
{
       register struct iovec *iov;

again:
       if (uio->uio_iovcnt == 0)
               panic("ureadc");
       iov = uio->uio_iov;
       if (iov->iov_len <= 0 || uio->uio_resid <= 0) {
               uio->uio_iovcnt--;
               uio->uio_iov++;
               goto again;
       }
       switch (uio->uio_segflg) {

       case 0:
               if (subyte(iov->iov_base, c) < 0)
                       return (EFAULT);
               break;

       case 1:
               *iov->iov_base = c;
               break;

       case 2:
               if (suibyte(iov->iov_base, c) < 0)
                       return (EFAULT);
               break;
       }
       iov->iov_base++;
       iov->iov_len--;
       uio->uio_resid--;
       uio->uio_offset++;
       return (0);
}

#ifdef notdef
/*
* Get next character written in by user from uio.
*/
uwritec(uio)
       struct uio *uio;
{
       register struct iovec *iov;
       register int c;

again:
       if (uio->uio_iovcnt <= 0 || uio->uio_resid <= 0)
               panic("uwritec");
       iov = uio->uio_iov;
       if (iov->iov_len == 0) {
               uio->uio_iovcnt--;
               uio->uio_iov++;
               goto again;
       }
       switch (uio->uio_segflg) {

       case 0:
               c = fubyte(iov->iov_base);
               break;

       case 1:
               c = *iov->iov_base & 0377;
               break;

       case 2:
               c = fuibyte(iov->iov_base);
               break;
       }
       if (c < 0)
               return (-1);
       iov->iov_base++;
       iov->iov_len--;
       uio->uio_resid--;
       uio->uio_offset++;
       return (c & 0377);
}
#endif