generalize asm-generic/ioctl.h to allow overriding values

In the spirit of a number of other asm-generic header files,
generalize asm-generic/ioctl.h to allow arch-specific ioctl.h headers
to simply override _IOC_SIZEBITS and/or _IOC_DIRBITS before including
this header file, allowing a number of ioctl.h header files to be
shortened considerably.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Robert P. J. Day 2008-04-29 01:02:54 -07:00 committed by Linus Torvalds
parent 098ef1c0ea
commit 10521bd9f7

View file

@ -21,8 +21,19 @@
*/
#define _IOC_NRBITS 8
#define _IOC_TYPEBITS 8
#define _IOC_SIZEBITS 14
#define _IOC_DIRBITS 2
/*
* Let any architecture override either of the following before
* including this file.
*/
#ifndef _IOC_SIZEBITS
# define _IOC_SIZEBITS 14
#endif
#ifndef _IOC_DIRBITS
# define _IOC_DIRBITS 2
#endif
#define _IOC_NRMASK ((1 << _IOC_NRBITS)-1)
#define _IOC_TYPEMASK ((1 << _IOC_TYPEBITS)-1)
@ -35,11 +46,21 @@
#define _IOC_DIRSHIFT (_IOC_SIZESHIFT+_IOC_SIZEBITS)
/*
* Direction bits.
* Direction bits, which any architecture can choose to override
* before including this file.
*/
#define _IOC_NONE 0U
#define _IOC_WRITE 1U
#define _IOC_READ 2U
#ifndef _IOC_NONE
# define _IOC_NONE 0U
#endif
#ifndef _IOC_WRITE
# define _IOC_WRITE 1U
#endif
#ifndef _IOC_READ
# define _IOC_READ 2U
#endif
#define _IOC(dir,type,nr,size) \
(((dir) << _IOC_DIRSHIFT) | \