[POWERPC] Cleanup SMT thread handling

This cleans up the SMT thread handling, removing some hard coded
assumptions and providing a set of helpers to convert between linux
cpu numbers, thread numbers and cores.

This implementation requires the number of threads per core to be a
power of 2 and identical on all cores in the system, but it's an
implementation detail, not an API requirement and so this limitation
can be lifted in the future if anybody ever needs it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/cell/smp.c b/arch/powerpc/platforms/cell/smp.c
index e4438456c86..efb3964457b 100644
--- a/arch/powerpc/platforms/cell/smp.c
+++ b/arch/powerpc/platforms/cell/smp.c
@@ -42,6 +42,7 @@
 #include <asm/firmware.h>
 #include <asm/system.h>
 #include <asm/rtas.h>
+#include <asm/cputhreads.h>
 
 #include "interrupt.h"
 #include <asm/udbg.h>
@@ -182,7 +183,7 @@ static int smp_cell_cpu_bootable(unsigned int nr)
          */
         if (system_state < SYSTEM_RUNNING &&
             cpu_has_feature(CPU_FTR_SMT) &&
-            !smt_enabled_at_boot && nr % 2 != 0)
+            !smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
                 return 0;
 
         return 1;