[tip:locking/core] locking/arch, powerpc/rtas: Use arch_spin_lock() instead of arch_spin_lock_flags()

[tip-bot for Will Deacon <tipbot@zytor.com>]

Commit-ID:  58788a9b6060890e481c8111fac43d065560ebcb
Gitweb:     https://git.kernel.org/tip/58788a9b6060890e481c8111fac43d065560ebcb
Author:     Will Deacon <will.deacon@arm.com>
AuthorDate: Wed, 18 Oct 2017 12:51:09 +0100
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 18 Oct 2017 15:15:07 +0200

locking/arch, powerpc/rtas: Use arch_spin_lock() instead of arch_spin_lock_flags()

arch_spin_lock_flags() is an internal part of the spinlock implementation
and is no longer available when SMP=n and DEBUG_SPINLOCK=y, so the PPC
RTAS code fails to compile in this configuration:

   arch/powerpc/kernel/rtas.c: In function 'lock_rtas':
>> arch/powerpc/kernel/rtas.c:81:2: error: implicit declaration of function 'arch_spin_lock_flags' [-Werror=implicit-function-declaration]
     arch_spin_lock_flags(&rtas.lock, flags);
     ^~~~~~~~~~~~~~~~~~~~

Since there's no good reason to use arch_spin_lock_flags() here (the code
in question already calls local_irq_save(flags)), switch it over to
arch_spin_lock and get things building again.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1508327469-20231-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/powerpc/kernel/rtas.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1643e9e..3f1c4fc 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -78,7 +78,7 @@ static unsigned long lock_rtas(void)
 
 	local_irq_save(flags);
 	preempt_disable();
-	arch_spin_lock_flags(&rtas.lock, flags);
+	arch_spin_lock(&rtas.lock);
 	return flags;
 }