[v4] powerpc: spinlock: Fix spin_unlock_wait()

[Michael Ellerman]

On Fri, 2016-10-06 at 03:51:28 UTC, Boqun Feng wrote:
> There is an ordering issue with spin_unlock_wait() on powerpc, because
> the spin_lock primitive is an ACQUIRE and an ACQUIRE is only ordering
> the load part of the operation with memory operations following it.
...
> 
> Suggested-by: "Paul E. McKenney" <paulmck at linux.vnet.ibm.com>
> Signed-off-by: Boqun Feng <boqun.feng at gmail.com>
> Reviewed-by: "Paul E. McKenney" <paulmck at linux.vnet.ibm.com>
> [mpe: Inline the "nop" ll/sc loop and set EH=0, munge change log]
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/6262db7c088bbfc26480d10144

cheers