| commit | 3e2e0d2c222bdf5bafd722dec1618fa6073ef372 | |
| author | Chris Metcalf <cmetcalf@tilera.com> | |
| Tue, 9 Apr 2013 16:33:07 +0000 (9 12:33 -0400) | ||
| committer | Linus Torvalds <torvalds@linux-foundation.org> | |
| Tue, 9 Apr 2013 17:08:14 +0000 (9 10:08 -0700) | ||
| tree | 04ea03bb23d59080ce52012095591874cad6cf49 | treesnapshot (tar.gz zip) |
| parent | 84ee9805bc7406bee35f2d62001440c81059f073 | commitdiff |
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>
[ This came about from me wondering about the synchronization rules of
__insn_mtspr() - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
[ This came about from me wondering about the synchronization rules of
__insn_mtspr() - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| arch/tile/include/asm/irqflags.h | diffblobblamehistory |