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author | Poul-Henning Kamp <phk@FreeBSD.org> | 1999-05-11 19:55:07 +0000 |
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committer | Poul-Henning Kamp <phk@FreeBSD.org> | 1999-05-11 19:55:07 +0000 |
commit | bfbb9ce67005673c7b7c8b2267024adef44f7d1d (patch) | |
tree | 9ffcbddb82416102ac7aed6b4c9c9b5bf02d13e3 /sys/kern/kern_conf.c | |
parent | ac9a7ff18c4b3ed2974b52ffccdddff73dfd5cad (diff) | |
download | src-bfbb9ce67005673c7b7c8b2267024adef44f7d1d.tar.gz src-bfbb9ce67005673c7b7c8b2267024adef44f7d1d.zip |
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).
Notes
Notes:
svn path=/head/; revision=47028
Diffstat (limited to 'sys/kern/kern_conf.c')
-rw-r--r-- | sys/kern/kern_conf.c | 75 |
1 files changed, 73 insertions, 2 deletions
diff --git a/sys/kern/kern_conf.c b/sys/kern/kern_conf.c index c20e2aa87214..e6aa7389ca9a 100644 --- a/sys/kern/kern_conf.c +++ b/sys/kern/kern_conf.c @@ -30,7 +30,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: kern_conf.c,v 1.35 1999/05/09 08:18:12 phk Exp $ + * $Id: kern_conf.c,v 1.36 1999/05/09 13:00:46 phk Exp $ */ #include <sys/param.h> @@ -70,7 +70,15 @@ cdevsw_add(dev_t *descrip, struct cdevsw *newentry, struct cdevsw **oldentry) { - int i ; + int i; + static int setup; + + if (!setup) { + for (i = 0; i < NUMCDEV; i++) + if (!bmaj2cmaj[i]) + bmaj2cmaj[i] = 254; + setup++; + } if ( *descrip == NODEV) { /* auto (0 is valid) */ /* @@ -161,3 +169,66 @@ devsw_module_handler(module_t mod, int what, void* arg) else return 0; } + +/* + * dev_t and u_dev_t primitives + */ + +#define DEVT_FASCIST 1 + +int +major(dev_t x) +{ +#ifdef DEVT_FASCIST + return(253 - ((x >> 8) & 0xff)); +#else + return((x >> 8) & 0xff); +#endif +} + +int +minor(dev_t x) +{ + return(x & 0xffff00ff); +} + +dev_t +makedev(int x, int y) +{ +#ifdef DEVT_FASCIST + return (((253 - x) << 8) | y); +#else + return ((x << 8) | y); +#endif +} + +udev_t +dev2udev(dev_t x) +{ + return umakedev(major(x), minor(x)); +} + +dev_t +udev2dev(udev_t x, int b) +{ + return makedev(umajor(x), uminor(x)); +} + +int +uminor(udev_t dev) +{ + return(dev & 0xffff00ff); +} + +int +umajor(udev_t dev) +{ + return((dev & 0xff00) >> 8); +} + +udev_t +umakedev(int x, int y) +{ + return ((x << 8) | y); +} + |