summaryrefslogtreecommitdiffstats
path: root/arch/alpha/include/asm/ioctl.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/alpha/include/asm/ioctl.h')
-rw-r--r--arch/alpha/include/asm/ioctl.h66
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/ioctl.h b/arch/alpha/include/asm/ioctl.h
new file mode 100644
index 00000000000..fc63727f417
--- /dev/null
+++ b/arch/alpha/include/asm/ioctl.h
@@ -0,0 +1,66 @@
+#ifndef _ALPHA_IOCTL_H
+#define _ALPHA_IOCTL_H
+
+/*
+ * The original linux ioctl numbering scheme was just a general
+ * "anything goes" setup, where more or less random numbers were
+ * assigned. Sorry, I was clueless when I started out on this.
+ *
+ * On the alpha, we'll try to clean it up a bit, using a more sane
+ * ioctl numbering, and also trying to be compatible with OSF/1 in
+ * the process. I'd like to clean it up for the i386 as well, but
+ * it's so painful recognizing both the new and the old numbers..
+ */
+
+#define _IOC_NRBITS 8
+#define _IOC_TYPEBITS 8
+#define _IOC_SIZEBITS 13
+#define _IOC_DIRBITS 3
+
+#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 _IOC_NONE could be 0, but OSF/1 gives it a bit.
+ * And this turns out useful to catch old ioctl numbers in header
+ * files for us.
+ */
+#define _IOC_NONE 1U
+#define _IOC_READ 2U
+#define _IOC_WRITE 4U
+
+#define _IOC(dir,type,nr,size) \
+ ((unsigned int) \
+ (((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 them.. */
+#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 /* _ALPHA_IOCTL_H */