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| author | Vineet Gupta <vgupta@synopsys.com> | 2014-11-13 10:17:46 (GMT) |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2014-12-12 10:32:46 (GMT) |
| commit | 88ec11b0f82b517b4f1c13f57096db5c8872fccb (patch) | |
| tree | f119899229726c594668a6ac4c50df6a79cbcaca | |
| parent | 9fb92eb1160d7e967f233cdfe2b718acff325b6e (diff) | |
| download | linux-88ec11b0f82b517b4f1c13f57096db5c8872fccb.tar.xz | |
ARC: document memory clobber in irq control macros
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
| -rw-r--r-- | arch/arc/include/asm/irqflags.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arc/include/asm/irqflags.h b/arch/arc/include/asm/irqflags.h index 742816f..27ecc69 100644 --- a/arch/arc/include/asm/irqflags.h +++ b/arch/arc/include/asm/irqflags.h @@ -41,6 +41,15 @@ /****************************************************************** * IRQ Control Macros + * + * All of them have "memory" clobber (compiler barrier) which is needed to + * ensure that LD/ST requiring irq safetly (R-M-W when LLSC is not available) + * are redone after IRQs are re-enabled (and gcc doesn't reuse stale register) + * + * Noted at the time of Abilis Timer List corruption + * Orig Bug + Rejected solution : https://lkml.org/lkml/2013/3/29/67 + * Reasoning : https://lkml.org/lkml/2013/4/8/15 + * ******************************************************************/ /* |