From: Will Deacon Date: Thu, 19 Sep 2013 18:06:46 +0000 (+0100) Subject: lockref: use cmpxchg64 explicitly for lockless updates X-Git-Tag: v3.12-rc2~11 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8f4c344696b9f9f8471d7f342076ef10ed7f66a5;p=pandora-kernel.git lockref: use cmpxchg64 explicitly for lockless updates The cmpxchg() function tends not to support 64-bit arguments on 32-bit architectures. This could be either due to use of unsigned long arguments (like on ARM) or lack of instruction support (cmpxchgq on x86). However, these architectures may implement a specific cmpxchg64() function to provide 64-bit cmpxchg support instead. Since the lockref code requires a 64-bit cmpxchg and relies on the architecture selecting ARCH_USE_CMPXCHG_LOCKREF, move to using cmpxchg64 instead of cmpxchg and allow 32-bit architectures to make use of the lockless lockref implementation. Cc: Waiman Long Signed-off-by: Will Deacon Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed