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linux/arch/powerpc/include/asm/cpuidle.h

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powernv/cpuidle: Redesign idle states management 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>
2014-12-09 18:56:52 +00:00
#ifndef _ASM_POWERPC_CPUIDLE_H
#define _ASM_POWERPC_CPUIDLE_H
#ifdef CONFIG_PPC_POWERNV
/* Used in powernv idle state management */
#define PNV_THREAD_RUNNING 0
#define PNV_THREAD_NAP 1
#define PNV_THREAD_SLEEP 2
#define PNV_THREAD_WINKLE 3
#define PNV_CORE_IDLE_LOCK_BIT 0x100
#define PNV_CORE_IDLE_THREAD_BITS 0x0FF
#ifndef __ASSEMBLY__
extern u32 pnv_fastsleep_workaround_at_entry[];
extern u32 pnv_fastsleep_workaround_at_exit[];
powerpc/powernv: Add platform support for stop instruction 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>
2016-07-08 06:20:49 +00:00
extern u64 pnv_first_deep_stop_state;
powernv/cpuidle: Redesign idle states management 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>
2014-12-09 18:56:52 +00:00
#endif
#endif
#endif
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