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powerpc/powernv: Simplify lazy IRQ handling in CPU offline

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Rather than concern ourselves with any soft-mask logic in the CPU
hotplug handler, just hard disable interrupts. This ensures there
are no lazy-irqs pending, which means we can call directly to idle
instruction in order to sleep.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin
2017-06-13 23:05:46 +10:00
committed by Michael Ellerman
parent 2201f994a5
commit 2525db04d1
2 changed files with 29 additions and 23 deletions
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23
arch/powerpc/platforms/powernv/idle.c
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@@ -352,25 +352,31 @@ void power9_idle(void)
/*
* pnv_cpu_offline: A function that puts the CPU into the deepest
* available platform idle state on a CPU-Offline.
* interrupts hard disabled and no lazy irq pending.
*/
unsigned long pnv_cpu_offline(unsigned int cpu)
{
unsigned long srr1;
u32 idle_states = pnv_get_supported_cpuidle_states();
ppc64_runlatch_off();
if (cpu_has_feature(CPU_FTR_ARCH_300) && deepest_stop_found) {
srr1 = __power9_idle_type(pnv_deepest_stop_psscr_val,
pnv_deepest_stop_psscr_mask);
unsigned long psscr;
psscr = mfspr(SPRN_PSSCR);
psscr = (psscr & ~pnv_deepest_stop_psscr_mask) |
pnv_deepest_stop_psscr_val;
srr1 = power9_idle_stop(psscr);
} else if (idle_states & OPAL_PM_WINKLE_ENABLED) {
srr1 = __power7_idle_type(PNV_THREAD_WINKLE);
srr1 = power7_idle_insn(PNV_THREAD_WINKLE);
} else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
(idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
srr1 = __power7_idle_type(PNV_THREAD_SLEEP);
srr1 = power7_idle_insn(PNV_THREAD_SLEEP);
} else if (idle_states & OPAL_PM_NAP_ENABLED) {
srr1 = __power7_idle_type(PNV_THREAD_NAP);
srr1 = power7_idle_insn(PNV_THREAD_NAP);
} else {
ppc64_runlatch_off();
/* This is the fallback method. We emulate snooze */
while (!generic_check_cpu_restart(cpu)) {
HMT_low();
@@ -378,9 +384,10 @@ unsigned long pnv_cpu_offline(unsigned int cpu)
}
srr1 = 0;
HMT_medium();
ppc64_runlatch_on();
}
ppc64_runlatch_on();
return srr1;
}
#endif