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authorShreyas B. Prabhu <shreyas@linux.vnet.ibm.com>2014-12-09 21:56:52 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2014-12-15 02:46:40 +0300
commit7cba160ad789a3ad7e68b92bf20eaad6ed171f80 (patch)
treeef57d54fcf61e5acf912e03004c0913457d3832b /drivers/cpuidle
parent8eb8ac89a364305d05ad16be983b7890eb462cc3 (diff)
downloadlinux-7cba160ad789a3ad7e68b92bf20eaad6ed171f80.tar.xz
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>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle-powernv.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 0a7d827897e4..a489b56e92df 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -208,7 +208,8 @@ static int powernv_add_idle_states(void)
nr_idle_states++;
}
- if (flags & OPAL_PM_SLEEP_ENABLED) {
+ if (flags & OPAL_PM_SLEEP_ENABLED ||
+ flags & OPAL_PM_SLEEP_ENABLED_ER1) {
/* Add FASTSLEEP state */
strcpy(powernv_states[nr_idle_states].name, "FastSleep");
strcpy(powernv_states[nr_idle_states].desc, "FastSleep");