ARC: document memory clobber in irq control macros

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2014-11-13 15:47:46 +05:30
parent 9fb92eb116
commit 88ec11b0f8

View File

@ -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
*
******************************************************************/
/*