>> Maybe I should send another patch tonight, just for playing.
> Please, I'd like that.
Below a random version of kdev_t.h.
(The file is smaller than the patch.)
kdev_t is the kernel-internal representation
dev_t is the kernel idea of the user space representation
(of course glibc uses 64 bits, split up as 8+8 :-)
kdev_t can be equal to dev_t.
The file below completely randomly makes kdev_t
64 bits, split up 32+32, and dev_t 32 bits, split up 12+20.
Andries
------------------------------------------------------------
#ifndef _LINUX_KDEV_T_H
#define _LINUX_KDEV_T_H
#ifdef __KERNEL__
typedef struct {
unsigned long long value;
} kdev_t;
#define KDEV_MINOR_BITS 32
#define KDEV_MAJOR_BITS 32
#define KDEV_MINOR_MASK ((1ULL << KDEV_MINOR_BITS) - 1)
#define __mkdev(major, minor) (((unsigned long long)(major) << KDEV_MINOR_BITS) + (minor))
#define mk_kdev(major, minor) ((kdev_t) { __mkdev(major,minor) } )
/*
* The "values" are just _cookies_, usable for
* internal equality comparisons and for things
* like NFS filehandle conversion.
*/
static inline unsigned long long kdev_val(kdev_t dev)
{
return dev.value;
}
static inline kdev_t val_to_kdev(unsigned long long val)
{
kdev_t dev;
dev.value = val;
return dev;
}
#define HASHDEV(dev) (kdev_val(dev))
#define NODEV (mk_kdev(0,0))
extern const char * kdevname(kdev_t); /* note: returns pointer to static data! */
static inline int kdev_same(kdev_t dev1, kdev_t dev2)
{
return dev1.value == dev2.value;
}
#define kdev_none(d1) (!kdev_val(d1))
#define minor(dev) (unsigned int)((dev).value & KDEV_MINOR_MASK)
#define major(dev) (unsigned int)((dev).value >> KDEV_MINOR_BITS)
/* These are for user-level "dev_t" */
#define MINORBITS 8
#define MINORMASK ((1U << MINORBITS) - 1)
#define DEV_MINOR_BITS 20
#define DEV_MAJOR_BITS 12
#define DEV_MINOR_MASK ((1U << DEV_MINOR_BITS) - 1)
#define DEV_MAJOR_MASK ((1U << DEV_MAJOR_BITS) - 1)
#include <linux/types.h> /* dev_t */
#define MAJOR(dev) ((unsigned int)(((dev) & 0xffff0000) ? ((dev) >> DEV_MINOR_BITS) & DEV_MAJOR_MASK : ((dev) >> 8) & 0xff))
#define MINOR(dev) ((unsigned int)(((dev) & 0xffff0000) ? ((dev) & DEV_MINOR_MASK) : ((dev) & 0xff)))
#define MKDEV(ma,mi) ((dev_t)((((ma) & ~0xff) == 0 && ((mi) & ~0xff) == 0) ? (((ma) << 8) | (mi)) : (((ma) << DEV_MINOR_BITS) | (mi))))
/*
* Conversion functions
*/
static inline int kdev_t_to_nr(kdev_t dev)
{
unsigned int ma = major(dev);
unsigned int mi = minor(dev);
return MKDEV(ma, mi);
}
static inline kdev_t to_kdev_t(dev_t dev)
{
unsigned int ma = MAJOR(dev);
unsigned int mi = MINOR(dev);
return mk_kdev(ma, mi);
}
#else /* __KERNEL__ */
/*
Some programs want their definitions of MAJOR and MINOR and MKDEV
from the kernel sources. These must be the externally visible ones.
Of course such programs should be updated.
*/
#define MAJOR(dev) ((dev)>>8)
#define MINOR(dev) ((dev) & 0xff)
#define MKDEV(ma,mi) ((ma)<<8 | (mi))
#endif /* __KERNEL__ */
#endif
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Mon Mar 31 2003 - 22:00:26 EST