x86/asm: Add _ASM_RIP() macro for x86-64 (%rip) suffix

From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

commit f87bc8dc upstream.

Add a macro _ASM_RIP() to add a (%rip) suffix on 64 bits only. This is
useful for immediate memory references where one doesn't want gcc
to possibly use a register indirection as it may in the case of an "m"
constraint.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Link: https://lkml.kernel.org/r/20210910195910.2542662-3-hpa@zytor.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>