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Date: Thu, 16 Nov 2017 09:11:52 -0800
From: Sami Tolvanen <samitolvanen@google.com>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Yury Norov <ynorov@caviumnetworks.com>,
        Will Deacon <will.deacon@arm.com>, Alex Matveev <alxmtvv@gmail.com>,
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Subject: Re: [PATCH v2 11/18] arm64: make mrs_s and msr_s macros work with LTO
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On Thu, Nov 16, 2017 at 11:01:44AM -0600, Segher Boessenkool wrote:
> The thing with .purgem can work.  Inelegant, sure, but it can work :-)

It works, there are already functions in the kernel that use these
macros more than once. I agree that this might not be the most elegant
solution, but at least it allows us to use the same code path for both
compilers.

> Just make sure you do the macro define, the code that uses it, and the
> undefine, all in the same inline asm statement.

Yes, that's what we're doing here. Only KVM uses msr_s/msr_s directly,
everything else uses the (read|write)_sysreg_s wrappers instead, which
means the DEFINE/UNDEFINE macros are only needed in few places.

Sami