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- #ifndef _SYS_IOCCOM_H_
- #define _SYS_IOCCOM_H_
-
- /*
- * Ioctl's have the command encoded in the lower word, and the size of
- * any in or out parameters in the upper word. The high 3 bits of the
- * upper word are used to encode the in/out status of the parameter.
- */
- #define IOCPARM_MASK 0x1fff /* parameter length, at most 13 bits */
- #define IOCPARM_LEN(x) (((x) >> 16) & IOCPARM_MASK)
- #define IOCBASECMD(x) ((x) & ~(IOCPARM_MASK << 16))
- #define IOCGROUP(x) (((x) >> 8) & 0xff)
-
- #define IOCPARM_MAX 4096 /* max size of ioctl, mult. of NBPG */
- #define IOC_VOID 0x20000000 /* no parameters */
- #define IOC_OUT 0x40000000 /* copy out parameters */
- #define IOC_IN 0x80000000 /* copy in parameters */
- #define IOC_INOUT (IOC_IN|IOC_OUT)
- #define IOC_DIRMASK 0xe0000000 /* mask for IN/OUT/VOID */
-
- #define _IOC(inout,group,num,len) \
- (inout | ((len & IOCPARM_MASK) << 16) | ((group) << 8) | (num))
- #define _IO(g,n) _IOC(IOC_VOID, (g), (n), 0)
- #define _IOR(g,n,t) _IOC(IOC_OUT, (g), (n), sizeof(t))
- #define _IOW(g,n,t) _IOC(IOC_IN, (g), (n), sizeof(t))
- /* this should be _IORW, but stdio got there first */
- #define _IOWR(g,n,t) _IOC(IOC_INOUT, (g), (n), sizeof(t))
-
- #endif /* !_SYS_IOCCOM_H_ */
-