Kevin Hao e1f580e8ce powerpc/e6500: hw tablewalk: make sure we invalidate and write to the same tlb entry ... In order to workaround Erratum A-008139, we have to invalidate the tlb entry with tlbilx before overwriting. Due to the performance consideration, we don't add any memory barrier when acquire/release the tcd lock. This means the two load instructions for esel_next do have the possibility to return different value. This is definitely not acceptable due to the Erratum A-008139. We have two options to fix this issue: a) Add memory barrier when acquire/release tcd lock to order the load/store to esel_next. b) Just make sure to invalidate and write to the same tlb entry and tolerate the race that we may get the wrong value and overwrite the tlb entry just updated by the other thread. We observe better performance using option b. So reserve an additional register to save the value of the esel_next. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Scott Wood <scottwood@freescale.com>		2015-10-27 18:14:40 -05:00
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asm	powerpc/e6500: hw tablewalk: make sure we invalidate and write to the same tlb entry	2015-10-27 18:14:40 -05:00
uapi/asm	powerpc: Individual System V IPC system calls	2015-10-15 20:31:57 +11:00