make kernel-side POLL... arch-independent

mangle/demangle on the way to/from userland

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/mips/include/uapi/asm/poll.h

@@ -2,8 +2,25 @@
 #ifndef __ASM_POLL_H
 #define __ASM_POLL_H
 
+#ifndef __KERNEL__
 #define POLLWRNORM	POLLOUT
 #define POLLWRBAND	(__force __poll_t)0x0100
+#else
+#define __ARCH_HAS_MANGLED_POLL
+static inline __u16 mangle_poll(__poll_t val)
+{
+	__u16 v = (__force __u16)val;
+	/* bit 9 -> bit 8, bit 8 -> bit 2 */
+	return (v & ~0x300) | ((v & 0x200) >> 1) | ((v & 0x100) >> 6);
+}
+
+static inline __poll_t demangle_poll(__u16 v)
+{
+        /* bit 8 -> bit 9, bit 2 -> bits 2 and 8 */
+	return (__force __poll_t)((v & ~0x100) | ((v & 0x100) << 1) |
+				((v & 4) << 6));
+}
+#endif
 
 #include <asm-generic/poll.h>