3 commits

Author	SHA1	Message	Date
Nicolas Pitre	b8da46d3d5	clarify a usage constraint for cnt32_to_63() ... The cnt32_to_63 algorithm relies on proper counter data evaluation ordering to work properly. This was missing from the provided documentation. Let's augment the documentation with the missing usage constraint and fix the only instance that got it wrong. Signed-off-by: Nicolas Pitre <nico@fluxnic.net> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	2010-12-20 09:07:35 -08:00
Nicolas Pitre	058e3739f6	clarify usage expectations for cnt32_to_63() ... Currently, all existing users of cnt32_to_63() are fine since the CPU architectures where it is used don't do read access reordering, and user mode preemption is disabled already. It is nevertheless a good idea to better elaborate usage requirements wrt preemption, and use an explicit memory barrier on SMP to avoid different CPUs accessing the counter value in the wrong order. On UP a simple compiler barrier is sufficient. Signed-off-by: Nicolas Pitre <nico@marvell.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	2008-11-09 11:17:33 -08:00
David Howells	b4f151ff89	MN10300: Move asm-arm/cnt32_to_63.h to include/linux/ ... Move asm-arm/cnt32_to_63.h to include/linux/ so that MN10300 can make use of it too. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	2008-09-24 16:38:17 -07:00