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* powerpc: Convert cmp to cmpd in idle enter sequenceSegher Boessenkool2016-10-21
| | | | | | | | | | | | | | | | | | | | | PowerPC's "cmp" instruction has four operands. Normally people write "cmpw" or "cmpd" for the second cmp operand 0 or 1. But, frequently people forget, and write "cmp" with just three operands. With older binutils this is silently accepted as if this was "cmpw", while often "cmpd" is wanted. With newer binutils GAS will complain about this for 64-bit code. For 32-bit code it still silently assumes "cmpw" is what is meant. In this instance the code comes directly from ISA v2.07, including the cmp, but cmpd is correct. Backport to stable so that new toolchains can build old kernels. Fixes: 948cf67c4726 ("powerpc: Add NAP mode support on Power7 in HV mode") Cc: stable@vger.kernel.org # v3.0 Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com> Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv: Move IDLE_STATE_ENTER_SEQ macro to cpuidle.hMahesh Salgaonkar2016-08-09
| | | | | | | | | | Move IDLE_STATE_ENTER_SEQ macro to cpuidle.h so that MCE handler changes in subsequent patch can use it. No functionality change. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powerpc/powernv: Add platform support for stop instructionShreyas B. Prabhu2016-07-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | POWER ISA v3 defines a new idle processor core mechanism. In summary, a) new instruction named stop is added. This instruction replaces instructions like nap, sleep, rvwinkle. b) new per thread SPR named Processor Stop Status and Control Register (PSSCR) is added which controls the behavior of stop instruction. PSSCR layout: ---------------------------------------------------------- | PLS | /// | SD | ESL | EC | PSLL | /// | TR | MTL | RL | ---------------------------------------------------------- 0 4 41 42 43 44 48 54 56 60 PSSCR key fields: Bits 0:3 - Power-Saving Level Status. This field indicates the lowest power-saving state the thread entered since stop instruction was last executed. Bit 42 - Enable State Loss 0 - No state is lost irrespective of other fields 1 - Allows state loss Bits 44:47 - Power-Saving Level Limit This limits the power-saving level that can be entered into. Bits 60:63 - Requested Level Used to specify which power-saving level must be entered on executing stop instruction This patch adds support for stop instruction and PSSCR handling. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* powernv/cpuidle: Redesign idle states managementShreyas B. Prabhu2014-12-14
Deep idle states like sleep and winkle are per core idle states. A core enters these states only when all the threads enter either the particular idle state or a deeper one. There are tasks like fastsleep hardware bug workaround and hypervisor core state save which have to be done only by the last thread of the core entering deep idle state and similarly tasks like timebase resync, hypervisor core register restore that have to be done only by the first thread waking up from these state. The current idle state management does not have a way to distinguish the first/last thread of the core waking/entering idle states. Tasks like timebase resync are done for all the threads. This is not only is suboptimal, but can cause functionality issues when subcores and kvm is involved. This patch adds the necessary infrastructure to track idle states of threads in a per-core structure. It uses this info to perform tasks like fastsleep workaround and timebase resync only once per core. Signed-off-by: Shreyas B. Prabhu <shreyas@linux.vnet.ibm.com> Originally-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: linux-pm@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>