[PATCH 03/14] ARM: v6k: remove CPU_32v6K dependencies in asm/spinlock.h

[Russell King - ARM Linux]

On Tue, Jan 25, 2011 at 04:43:52PM +0000, Dave Martin wrote:
> A couple of questions on this:
> 
> 1) I notice these spinlock functions are generally marked inline.
> 
> Is that likely to happen in modules?  If so, there would be a need to
> do SMP_ON_UP fixups at module load time -- I don't think that's
> currently implemented.

No one should be using the arch_* spinlocks directly.  The spinlocks
are implemented in out of line code in kernel/spinlock.c

> 2) When building with this patch and CONFIG_SMP_ON_UP=y, I've seen
> vmlinux link errors like this:
> 
>   LD      .tmp_vmlinux1
> `.exit.text' referenced in section `.alt.smp.init' of
> drivers/built-in.o: defined in discarded section `.exit.text' of
> drivers/built-in.o
> make: *** [.tmp_vmlinux1] Error 1
> 
> I don't know whether this is caused by the patch directly or as a
> side-effect -- I've only noticed it in the linaro-2.6.37 tree so far.
> git bisect indentified this above patch as the first one with the
> error in that case.
> 
> I don't understand the section discarding logic too well, so I'm not
> sure how to fix it for now...

Hmm.  I don't see how that could happen, unless some driver is going
behind the spinlock APIs, or using our dsb_sev() directly.

I think you need to first track down what's responsible for inserting
architecture spinlock code into drivers.