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authorPreeti U Murthy <preeti@linux.vnet.ibm.com>2014-04-11 14:31:48 +0400
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-04-28 10:32:40 +0400
commitf203891117323dd31c11adcbba60452c933d604e (patch)
tree5cfbc57f6bbb8428c53b18fb65132e1086b90e45 /arch/powerpc
parent42dbfc8649737cb622b2a7e02045401c4c09561c (diff)
downloadlinux-f203891117323dd31c11adcbba60452c933d604e.tar.xz
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 <preeti@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/powernv/smp.c3
1 files changed, 3 insertions, 0 deletions
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 <asm/cputhreads.h>
#include <asm/xics.h>
#include <asm/opal.h>
+#include <asm/runlatch.h>
#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