On Mon 2016-07-18 23:27:49, Tomas Winkler wrote:

quoted

The user space API is achieved via two synchronous IOCTL.

IOCTLs?

Will fix
 

quoted

Simplified one, RPMB_IOC_REQ_CMD, were read result cycles is

performed

quoted

by the framework on behalf the user and second, RPMB_IOC_SEQ_CMD

where

quoted

the whole RPMB sequence including RESULT_READ is supplied by the caller.
The latter is intended for  easier adjusting  of the  applications
that use MMC_IOC_MULTI_CMD ioctl.

Why "  "?

Not sure I there is enough clue in your question. 

quoted

Signed-off-by: Tomas Winkler <redacted>

quoted

+
+static long rpmb_ioctl(struct file *fp, unsigned int cmd, unsigned
+long arg) {
+	return __rpmb_ioctl(fp, cmd, (void __user *)arg); }
+
+#ifdef CONFIG_COMPAT
+static long rpmb_compat_ioctl(struct file *fp, unsigned int cmd,
+			      unsigned long arg)
+{
+	return	__rpmb_ioctl(fp, cmd, compat_ptr(arg));
+}
+#endif /* CONFIG_COMPAT */

Description of the ioctl is missing, 

Will add. 

and it should certainly be designed in a way

that it does not need compat support.

The compat_ioctl handler just casts the compat_ptr, I believe this should be done unless the ioctl is globaly registered in fs/compat_ioctl.c, but I might be wrong.
Tomas