Divorce "dev_t" from the "major|minor" bitmap, which is now called

udev_t in the kernel but still called dev_t in userland.

Provide functions to manipulate both types:
        major()         umajor()
        minor()         uminor()
        makedev()       umakedev()
        dev2udev()      udev2dev()

For now they're functions, they will become in-line functions
after one of the next two steps in this process.

Return major/minor/makedev to macro-hood for userland.

Register a name in cdevsw[] for the "filedescriptor" driver.

In the kernel the udev_t appears in places where we have the
major/minor number combination, (ie: a potential device: we
may not have the driver nor the device), like in inodes, vattr,
cdevsw registration and so on, whereas the dev_t appears where
we carry around a reference to a actual device.

In the future the cdevsw and the aliased-from vnode will be hung
directly from the dev_t, along with up to two softc pointers for
the device driver and a few houskeeping bits.  This will essentially
replace the current "alias" check code (same buck, bigger bang).

A little stunt has been provided to try to catch places where the
wrong type is being used (dev_t vs udev_t), if you see something
not working, #undef DEVT_FASCIST in kern/kern_conf.c and see if
it makes a difference.  If it does, please try to track it down
(many hands make light work) or at least try to reproduce it
as simply as possible, and describe how to do that.

Without DEVT_FASCIST I belive this patch is a no-op.

Stylistic/posixoid comments about the userland view of the <sys/*.h>
files welcome now, from userland they now contain the end result.

Next planned step: make all dev_t's refer to the same devsw[] which
means convert BLK's to CHR's at the perimeter of the vnodes and
other places where they enter the game (bootdev, mknod, sysctl).

2 files changed, 4 insertions, 8 deletions

diff --git a/sys/miscfs/specfs/spec_vnops.c b/sys/miscfs/specfs/spec_vnops.c
index 74c30c7..636bc44 100644
--- a/sys/miscfs/specfs/spec_vnops.c
+++ b/sys/miscfs/specfs/spec_vnops.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)spec_vnops.c	8.14 (Berkeley) 5/21/95
- * $Id: spec_vnops.c,v 1.84 1999/05/07 10:11:05 phk Exp $
+ * $Id: spec_vnops.c,v 1.85 1999/05/08 06:39:55 phk Exp $
  */
 
 #include <sys/param.h>
@@ -162,7 +162,7 @@ spec_open(ap)
 {
 	struct proc *p = ap->a_p;
 	struct vnode *bvp, *vp = ap->a_vp;
-	dev_t bdev, dev = (dev_t)vp->v_rdev;
+	dev_t bdev, dev = vp->v_rdev;
 	int maj = major(dev);
 	int error;
 	struct cdevsw *dsw;
diff --git a/sys/miscfs/specfs/specdev.h b/sys/miscfs/specfs/specdev.h
index a7e2bab..d0cfd77 100644
--- a/sys/miscfs/specfs/specdev.h
+++ b/sys/miscfs/specfs/specdev.h
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)specdev.h	8.6 (Berkeley) 5/21/95
- * $Id: specdev.h,v 1.15 1998/04/19 23:32:29 julian Exp $
+ * $Id: specdev.h,v 1.16 1999/02/25 05:22:30 dillon Exp $
  */
 
 /*
@@ -60,11 +60,7 @@ struct specinfo {
  * Special device management
  */
 #define	SPECHSZ	64
-#if	((SPECHSZ&(SPECHSZ-1)) == 0)
-#define	SPECHASH(rdev)	(((rdev>>5)+(rdev))&(SPECHSZ-1))
-#else
-#define	SPECHASH(rdev)	(((unsigned)((rdev>>5)+(rdev)))%SPECHSZ)
-#endif
+#define	SPECHASH(rdev)	(((unsigned)(minor(rdev)))%SPECHSZ)
 
 extern	struct vnode *speclisth[SPECHSZ];