diff options
Diffstat (limited to 'arch/powerpc/platforms/powernv/smp.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 0d354e19ef92..db09c7022635 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -39,6 +39,7 @@ #include <asm/cpuidle.h> #include <asm/kexec.h> #include <asm/reg.h> +#include <asm/powernv.h> #include "powernv.h" @@ -153,6 +154,7 @@ static void pnv_smp_cpu_kill_self(void) { unsigned int cpu; unsigned long srr1, wmask; + u64 lpcr_val; /* Standard hot unplug procedure */ /* @@ -174,6 +176,19 @@ 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 so as to let IPIs in. + * + * If the CPU gets woken up by a special wakeup, ensure that + * the SLW engine sets LPCR with decrementer bit cleared, else + * the CPU will come back to the kernel due to a spurious + * wakeup. + */ + lpcr_val = mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1; + pnv_program_cpu_hotplug_lpcr(cpu, lpcr_val); + while (!generic_check_cpu_restart(cpu)) { /* * Clear IPI flag, since we don't handle IPIs while @@ -246,6 +261,16 @@ static void pnv_smp_cpu_kill_self(void) } + /* + * Re-enable decrementer interrupts in LPCR. + * + * Further, we want stop states to be woken up by decrementer + * for non-hotplug cases. So program the LPCR via stop api as + * well. + */ + lpcr_val = mfspr(SPRN_LPCR) | (u64)LPCR_PECE1; + pnv_program_cpu_hotplug_lpcr(cpu, lpcr_val); + DBG("CPU%d coming online...\n", cpu); } |