ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()

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The mmiowb() macro is horribly difficult to use and drivers will continue
to work most of the time if they omit a call when it is required.

Rather than rely on driver authors getting this right, push mmiowb() into
arch_spin_unlock() for ia64. If this is deemed to be a performance issue,
a subsequent optimisation could make use of ARCH_HAS_MMIOWB to elide
the barrier in cases where no I/O writes were performed inside the
critical section.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

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This commit is contained in:

Will Deacon 2019-02-22 13:37:21 +00:00

parent 346e91ee09

commit 49ca6462fc

4 changed files with 27 additions and 18 deletions

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1

arch/ia64/include/asm/Kbuild

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17

arch/ia64/include/asm/io.h

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25

arch/ia64/include/asm/mmiowb.h

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2

arch/ia64/include/asm/spinlock.h

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