Fast sleep is an idle state, where the core and the L1 and L2 caches are brought down to a threshold voltage. This also means that the communication between L2 and L3 caches have to be fenced. However the current P8 chips have a bug wherein this fencing between L2 and L3 caches get delayed by a cpu cycle. This can delay L3 response to the other cpus if they request for data during this time. Thus they would fetch the same data from the memory which could lead to data corruption if L3 cache is not flushed.
This series overcomes above problem in kernel. Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Rafael J. Wysocki <r...@rjwysocki.net> Cc: linux...@vger.kernel.org Cc: linuxppc-...@lists.ozlabs.org Cc: Srivatsa S. Bhat <sriva...@mit.edu> Cc: Preeti U. Murthy <pre...@linux.vnet.ibm.com> Cc: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com> v2: Rebased on 3.17-rc7 Split from 'powerpc/powernv: Support for fastsleep and winkle' v1: https://lkml.org/lkml/2014/8/25/446 Preeti U Murthy (1): powerpc/powernv/cpuidle: Add workaround to enable fastsleep Shreyas B. Prabhu (1): powerpc/kvm/book3s_hv: Enable CPUs to run guest after waking up from fast-sleep Srivatsa S. Bhat (1): powerpc/powernv: Enable Offline CPUs to enter deep idle states arch/powerpc/include/asm/machdep.h | 3 + arch/powerpc/include/asm/opal.h | 7 ++ arch/powerpc/include/asm/processor.h | 4 +- arch/powerpc/kernel/exceptions-64s.S | 35 ++++---- arch/powerpc/kernel/idle.c | 19 ++++ arch/powerpc/kernel/idle_power7.S | 2 +- arch/powerpc/platforms/powernv/opal-wrappers.S | 1 + arch/powerpc/platforms/powernv/powernv.h | 7 ++ arch/powerpc/platforms/powernv/setup.c | 118 +++++++++++++++++++++++++ arch/powerpc/platforms/powernv/smp.c | 11 ++- drivers/cpuidle/cpuidle-powernv.c | 13 ++- 11 files changed, 194 insertions(+), 26 deletions(-) -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
