From f203891117323dd31c11adcbba60452c933d604e Mon Sep 17 00:00:00 2001 From: Preeti U Murthy Date: Fri, 11 Apr 2014 16:01:48 +0530 Subject: [PATCH] ppc/powernv: Set the runlatch bits correctly for offline cpus Up until now we have been setting the runlatch bits for a busy CPU and clearing it when a CPU enters idle state. The runlatch bit has thus been consistent with the utilization of a CPU as long as the CPU is online. However when a CPU is hotplugged out the runlatch bit is not cleared. It needs to be cleared to indicate an unused CPU. Hence this patch has the runlatch bit cleared for an offline CPU just before entering an idle state and sets it immediately after it exits the idle state. Signed-off-by: Preeti U Murthy Acked-by: Paul Mackerras Reviewed-by: Srivatsa S. Bhat Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/powernv/smp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 908672bdcea6..bf5fcd452168 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -30,6 +30,7 @@ #include #include #include +#include #include "powernv.h" @@ -156,7 +157,9 @@ static void pnv_smp_cpu_kill_self(void) */ mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); while (!generic_check_cpu_restart(cpu)) { + ppc64_runlatch_off(); power7_nap(); + ppc64_runlatch_on(); if (!generic_check_cpu_restart(cpu)) { DBG("CPU%d Unexpected exit while offline !\n", cpu); /* We may be getting an IPI, so we re-enable -- 2.20.1