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| author | Gautham R. Shenoy <ego@linux.vnet.ibm.com> | 2017-07-21 14:01:34 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-01 14:01:28 +0300 |
| commit | 24be85a23d1fcdc72264a062a2e4ebaaea48feab (patch) | |
| tree | 2628f824043e14a6c7b3dc08340aa854bc077209 /arch/powerpc/platforms/powernv/smp.c | |
| parent | e1c1cfed54326fd2b17c78f0c85092167fc0783b (diff) | |
| download | linux-24be85a23d1fcdc72264a062a2e4ebaaea48feab.tar.xz | |
powerpc/powernv: Clear PECE1 in LPCR via stop-api only on Hotplug
Currently we use the stop-api provided by the firmware to program the
SLW engine to restore the values of hypervisor resources that get lost
on deeper idle states (such as winkle). Since the deep states were
only used for CPU-Hotplug on POWER8 systems, we would program the LPCR
to have the PECE1 bit since Hotplugged CPUs shouldn't be spuriously
woken up by decrementer.
On POWER9, some of the deep platform idle states such as stop4 can be
used in cpuidle as well. In this case, we want the CPU in stop4 to be
woken up by the decrementer when some timer on the CPU expires.
In this patch, we program the stop-api for LPCR with PECE1
bit cleared only when we are offlining the CPU and set it
back once the CPU is online.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/powernv/smp.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 8 |
1 files changed, 0 insertions, 8 deletions
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index c6448c7aabe7..c17f81e433f7 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -165,12 +165,6 @@ static void pnv_smp_cpu_kill_self(void) if (cpu_has_feature(CPU_FTR_ARCH_207S)) wmask = SRR1_WAKEMASK_P8; - /* We don't want to take decrementer interrupts while we are offline, - * so clear LPCR:PECE1. We keep PECE2 (and LPCR_PECE_HVEE on P9) - * enabled as to let IPIs in. - */ - mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); - while (!generic_check_cpu_restart(cpu)) { /* * Clear IPI flag, since we don't handle IPIs while @@ -220,8 +214,6 @@ static void pnv_smp_cpu_kill_self(void) } - /* Re-enable decrementer interrupts */ - mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1); DBG("CPU%d coming online...\n", cpu); } |