- merge 0.7rc1 from b_devel to HEAD (20030612 merge point)

[fs/lustre-release.git] / lustre / include / ioctl.h

diff --git a/lustre/include/ioctl.h b/lustre/include/ioctl.h
new file mode 100644 (file)
index 0000000..a4ec8a5
--- /dev/null
+++ b/lustre/include/ioctl.h
@@ -0,0 +1,64 @@
+#ifndef _ASMI386_IOCTL_H
+#define _ASMI386_IOCTL_H
+
+/* ioctl command encoding: 32 bits total, command in lower 16 bits,
+ * size of the parameter structure in the lower 14 bits of the
+ * upper 16 bits.
+ * Encoding the size of the parameter structure in the ioctl request
+ * The highest 2 bits are reserved for indicating the ``access mode''.
+ * NOTE: This limits the max parameter size to 16kB -1 !
+ */
+
+/*
+ * The following is for compatibility across the various Linux
+ * platforms.  The i386 ioctl numbering scheme doesn't really enforce
+ * a type field.  De facto, however, the top 8 bits of the lower 16
+ * bits are indeed used as a type field, so we might just as well make
+ * this explicit here.  Please be sure to use the decoding macros
+ * below from now on.
+ */
+#define _IOC_NRBITS     8
+#define _IOC_TYPEBITS   8
+#define _IOC_SIZEBITS   14
+#define _IOC_DIRBITS    2
+
+#define _IOC_NRMASK     ((1 << _IOC_NRBITS)-1)
+#define _IOC_TYPEMASK   ((1 << _IOC_TYPEBITS)-1)
+#define _IOC_SIZEMASK   ((1 << _IOC_SIZEBITS)-1)
+#define _IOC_DIRMASK    ((1 << _IOC_DIRBITS)-1)
+
+#define _IOC_NRSHIFT    0
+#define _IOC_TYPESHIFT  (_IOC_NRSHIFT+_IOC_NRBITS)
+#define _IOC_SIZESHIFT  (_IOC_TYPESHIFT+_IOC_TYPEBITS)
+#define _IOC_DIRSHIFT   (_IOC_SIZESHIFT+_IOC_SIZEBITS)
+
+/*
+ * Direction bits.
+ */
+#define _IOC_NONE       0U
+#define _IOC_WRITE      1U
+#define _IOC_READ       2U
+
+#define _IOC(dir,type,nr,size) (((dir)  << _IOC_DIRSHIFT) | ((type) << _IOC_TYPESHIFT) | ((nr)   << _IOC_NRSHIFT) | ((size) << _IOC_SIZESHIFT))
+
+/* used to create numbers */
+#define _IO(type,nr)            _IOC(_IOC_NONE,(type),(nr),0)
+#define _IOR(type,nr,size)      _IOC(_IOC_READ,(type),(nr),sizeof(size))
+#define _IOW(type,nr,size)      _IOC(_IOC_WRITE,(type),(nr),sizeof(size))
+#define _IOWR(type,nr,size)     _IOC(_IOC_READ|_IOC_WRITE,(type),(nr),sizeof(size))
+
+/* used to decode ioctl numbers.. */
+#define _IOC_DIR(nr)            (((nr) >> _IOC_DIRSHIFT) & _IOC_DIRMASK)
+#define _IOC_TYPE(nr)           (((nr) >> _IOC_TYPESHIFT) & _IOC_TYPEMASK)
+#define _IOC_NR(nr)             (((nr) >> _IOC_NRSHIFT) & _IOC_NRMASK)
+#define _IOC_SIZE(nr)           (((nr) >> _IOC_SIZESHIFT) & _IOC_SIZEMASK)
+
+/* ...and for the drivers/sound files... */
+
+#define IOC_IN          (_IOC_WRITE << _IOC_DIRSHIFT)
+#define IOC_OUT         (_IOC_READ << _IOC_DIRSHIFT)
+#define IOC_INOUT       ((_IOC_WRITE|_IOC_READ) << _IOC_DIRSHIFT)
+#define IOCSIZE_MASK    (_IOC_SIZEMASK << _IOC_SIZESHIFT)
+#define IOCSIZE_SHIFT   (_IOC_SIZESHIFT)
+
+#endif /* _ASMI386_IOCTL_H */