Compilation fails with CONFIG_DEBUG_SPINLOCK

[Thomas Petazzoni <thomas.petazzoni@enix.org>]

Hello,

With the last CVS, if you check CONFIG_DEBUG_SPINLOCK, the compilation
fails :

arch/mips/kernel/built-in.o(.text+0x2e84): In function `probe_irq_on':
: undefined reference to `atomic_lock'
arch/mips/kernel/built-in.o(.text+0x2e88): In function `probe_irq_on':
: undefined reference to `atomic_lock'
arch/mips/kernel/built-in.o(.text+0x2e90): In function `probe_irq_on':
: undefined reference to `atomic_lock'
arch/mips/kernel/built-in.o(.text+0x2e94): In function `probe_irq_on':
: undefined reference to `atomic_lock'
arch/mips/kernel/built-in.o(.text+0x2ebc): In function `probe_irq_on':
: undefined reference to `atomic_lock'
arch/mips/kernel/built-in.o(.text+0x2ec0): more undefined references
to `atomic_lock' follow
make: *** [.tmp_vmlinux1] Error 1

Some macros in include/asm/atomic.h uses a spinlock called
atomic_lock. An "extern" definition is made at the top of the file,
but the real spinlock is not defined anywhere.

I think this is trivial to fix, but I'm not sure what is the right
place to declare the spin lock and to initialize it.

Thomas
-- 
PETAZZONI Thomas - thomas.petazzoni@enix.org 
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