tile: comment assumption about __insn_mtspr for <asm/irqflags.h>
authorChris Metcalf <cmetcalf@tilera.com>
Tue, 9 Apr 2013 16:33:07 +0000 (12:33 -0400)
committerChris Metcalf <cmetcalf@tilera.com>
Tue, 9 Apr 2013 16:33:07 +0000 (12:33 -0400)
commitffae3d0e3606b2e274c9ec1b969342d630b2ecae
tree8dbe20e674f88fa4b19a960a36ba45edef15bc86
parent39e8202bb3b83a826e5825b1a07bbbf30ae9a140
tile: comment assumption about __insn_mtspr for <asm/irqflags.h>

The arch_local_irq_save(), etc., routines are required to function
as compiler barriers.  They do, but it's subtle and requires knowing
that the gcc builtin __insn_mtspr() is marked as a memory clobber.
Provide a comment explaining the assumption.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
arch/tile/include/asm/irqflags.h